Radiographic evaluation of root canal fillings accomplished by undergraduate dental students.

PubMed

Yavari, Hamidreza; Samiei, Mohammad; Shahi, Shahriar; Borna, Zahra; Abdollahi, Amir Ardalan; Ghiasvand, Negar; Shariati, Gholamreza

2015-01-01

The purpose of this study was to evaluate the radiographic quality of root canal fillings by fourth-, fifth-, and sixth-year undergraduate students at Tabriz Faculty of Dentistry between 2006 and 2012. A total of 1183 root canal fillings in 620 teeth were evaluated by two investigators (and in case of disagreement by a third investigator) regarding the presence or absence of under-fillings, over-fillings and perforations. For each tooth, preoperative, working and postoperative radiographs were checked. The Pearson's chi-square test was used for statistical evaluation of the data. Inter-examiner agreement was measured by Cohen's kappa (k) values. The level of significance was set at 0.05. Total frequencies of over-filling, under-filling and perforation were 5.6%, 20.4% and 1.9%, respectively. There were significant differences between frequencies of over- and under-fillings (P<0.05). Unacceptable quality, under- and over-fillings were detected in 27.9% of 1183 evaluated canals. The technical quality of root canal therapies performed by undergraduate dental students using step-back preparation and lateral compaction techniques was unacceptable in almost one-fourth of the cases.

Effect of education intervention on the quality and long-term outcomes of root canal treatment in general practice.

PubMed

Koch, M; Wolf, E; Tegelberg, Å; Petersson, K

2015-07-01

To compare the technical quality and long-term outcomes of root canal treatment by general practitioners of a Swedish Public Dental Service, before and after an endodontic education including Ni-Ti rotary technique (NiTiR). A random sample was compiled, comprising one root filled tooth from each of 830 patients, treated by 69 general practitioners participating in the education: 414 teeth root filled in 2002, pre-education, using primarily stainless steel instrumentation and filling by lateral compaction, and 416 teeth root filled post-education (2005), using mainly NiTiR and single-cone obturation. Follow-up radiographs taken in 2009 were evaluated alongside immediate post-filling radiographs from 2002 to 2005. The density and length of the root fillings were registered. Periapical status was assessed by the Periapical Index (PAI), using two definitions of disease: apical periodontitis (AP) (PAI 3 + 4 + 5) and definite AP (PAI 4 + 5). Tooth survival was registered. Root fillings pre- and post-education were compared using chi-square and Fisher's exact tests. Crude extraction rates per 100 years were calculated for comparison of tooth survival. Explanatory variables (type of tooth, root filling quality, periapical status, marginal bone loss, type and quality of coronal restoration) in relation to the dependent variable (AP at follow-up) were analysed by multivariable logistic regression. Follow-up data were available for 229 (55%) of teeth treated pre- and 288 (69%) treated post-education: both tooth survival (P < 0.001) and root filling quality were significantly higher (P < 0.001) in the latter. However, there was no corresponding improvement in periapical status. Both pre- and post-education, root fillings with definite AP on completion of treatment had significantly higher odds of AP or definite AP at follow-up. For teeth treated post-education, inadequate root filling quality was significantly associated with AP at follow-up. Despite a higher tooth survival rate and a significant improvement in technical quality of root fillings after the education, there was no corresponding improvement in periapical status. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Fracture resistance of retreated roots using different retreatment systems.

PubMed

Er, Kursat; Tasdemir, Tamer; Siso, Seyda Herguner; Celik, Davut; Cora, Sabri

2011-08-01

This study was designed to evaluate the fracture resistance of retreated roots using different rotary retreatment systems. Forty eight freshly extracted human canine teeth with single straight root canals were instrumented sequentially increasing from size 30 to a size 55 using K-files whit a stepback technique. The teeth were randomly divided into three experimental and one control groups of 12 specimens each. The root canals were filled using cold lateral compaction of gutta-percha and AH Plus (Dentsply Detrey, Konstanz, Germany) sealer in experimental groups. Removal of gutta-percha was performed with the following devices and techniques: ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland), R-Endo (Micro-Mega, Besançon, France), and Mtwo (Sweden & Martina, Padova, Italy) rotary retreatment systems. Control group specimens were only instrumented, not filled or retreated. The specimens were then mounted in copper rings, were filled with a self-curing polymethylmethacrylate resin, and the force required to cause vertical root fracture was measured using a universal testing device. The force of fracture of the roots was recorded and the results in the various groups were compared. Statistical analysis was accomplished by one-way ANOVA and a post hoc Tukey tests. There were statistically significant differences between the control and experimental groups (P<.05). However, there were no significant differences among the experimental groups. Based on the results, all rotary retreatment techniques used in this in vitro study produced similar root weakness.

Detection of Fractured Endodontic Instruments in Root Canals: Comparison between Different Digital Radiography Systems and Cone-beam Computed Tomography.

PubMed

Ramos Brito, Ana Caroline; Verner, Francielle Silvestre; Junqueira, Rafael Binato; Yamasaki, Mayra Cristina; Queiroz, Polyane Mazucato; Freitas, Deborah Queiroz; Oliveira-Santos, Christiano

2017-04-01

This study compared the detection of fractured instruments in root canals with and without filling by periapical radiographs from 3 digital systems and cone-beam computed tomographic (CBCT) images with different resolutions. Thirty-one human molars (80 canals) were used. Root canals were divided into the following groups: the control group, without fillings; the fracture group, without fillings and with fractured files; the fill group, filled; and the fill/fracture group, filled and with fractured files. Digital radiographs in ortho-, mesio-, and distoradial directions were performed in 2 semidirect systems (VistaScan [Dürr Dental, Beitigheim-Bissinger, Germany] and Express [Instrumentarium Imaging, Tuusula, Finland]) and a direct system (SnapShot [Instrumentarium Imaging]). CBCT images were acquired with 0.085-mm and 0.2-mm voxel sizes. All images were assessed and reassessed by 4 observers for the presence or absence of fractured files on a 5-point scale. The sensitivity, specificity, and accuracy were calculated. In the absence of filling, accuracy values were high, and there were no statistical differences among the radiographic techniques, different digital systems, or the different CBCT voxels sizes. In the presence of filling, the accuracy of periapical radiographs was significantly higher than CBCT images. In general, SnapShot showed higher accuracy than VistaScan and Express. Periapical radiographs in 1 incidence were accurate for the detection of fractured endodontic instruments inside the root canal in the absence or presence of filling, suggesting that this technique should be the first choice as well as the direct digital radiographic system. In the presence of filling, the decision to perform a CBCT examination must take into consideration its low accuracy. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

IS GUTTACORE MORE EASILY REMOVED FROM THE ROOT CANAL THAN THERMAFIL? AN EX-VIVO STUDY.

PubMed

Nevares, Giselle; de Albuquerque, Diana Santana; Bueno, Carlos Eduardo da Silveira; Cunha, Rodrigo Sanches

2015-01-01

GuttaCore is a new cross-linked gutta-percha carrier. Its handling time and ease of removal were compared with those of a plastic carrier (Thermafil) and the continuous wave of condensation technique (control). Forty-five maxillary central incisors were randomly divided 3 groups according to filling technique and retreatment was carried out in all samples with NiTi rotary files, hand files and ultrasonic inserts. Time required for filling removal was recorded. Roots were then split longitudinally and photographed under 5x magnification, and residual filling material was quantified. Removal time was significantly longer for Thermafil (7.10 minutes) than GuttaCore (2.91 minutes) and the control group (1.93 minutes) (p < 0.001). The amount of residual filling material did not differ among the groups: Thermafil 8.31%, GuttaCore 6.27 and control 8.68% (p > 0.05). In conclusion, replacing plastic core with cross-linked gutta-percha allows easier removal of carrier from the root canal. The remnants of filling material in all samples illustrate that retreatment remains a challenge in endodontics.

Radiographic Evaluation of Root Canal Fillings Accomplished by Undergraduate Dental Students

PubMed Central

Yavari, Hamidreza; Samiei, Mohammad; Shahi, Shahriar; Borna, Zahra; Abdollahi, Amir Ardalan; Ghiasvand, Negar; Shariati, Gholamreza

2015-01-01

Introduction: The purpose of this study was to evaluate the radiographic quality of root canal fillings by fourth-, fifth-, and sixth-year undergraduate students at Tabriz Faculty of Dentistry between 2006 and 2012. Methods and Materials: A total of 1183 root canal fillings in 620 teeth were evaluated by two investigators (and in case of disagreement by a third investigator) regarding the presence or absence of under-fillings, over-fillings and perforations. For each tooth, preoperative, working and postoperative radiographs were checked. The Pearson’s chi-square test was used for statistical evaluation of the data. Inter-examiner agreement was measured by Cohen’s kappa (k) values. The level of significance was set at 0.05. Results: Total frequencies of over-filling, under-filling and perforation were 5.6%, 20.4% and 1.9%, respectively. There were significant differences between frequencies of over- and under-fillings (P<0.05). Unacceptable quality, under- and over-fillings were detected in 27.9% of 1183 evaluated canals. Conclusion: The technical quality of root canal therapies performed by undergraduate dental students using step-back preparation and lateral compaction techniques was unacceptable in almost one-fourth of the cases. PMID:25834598

Efficacy of ProTaper universal retreatment files in removing filling materials during root canal retreatment.

PubMed

Giuliani, Valentina; Cocchetti, Roberto; Pagavino, Gabriella

2008-11-01

The aim of this study was to evaluate the efficacy of the ProTaper Universal System rotary retreatment system and of Profile 0.06 and hand instruments (K-file) in the removal of root filling materials. Forty-two extracted single-rooted anterior teeth were selected. The root canals were enlarged with nickel-titanium (NiTi) rotary files, filled with gutta-percha and sealer, and randomly divided into 3 experimental groups. The filling materials were removed with solvent in conjunction with one of the following devices and techniques: the ProTaper Universal System for retreatment, ProFile 0.06, and hand instruments (K-file). The roots were longitudinally sectioned, and the image of the root surface was photographed. The images were captured in JPEG format; the areas of the remaining filling materials and the time required for removing the gutta-percha and sealer were calculated by using the nonparametric one-way Kruskal-Wallis test and Tukey-Kramer tests, respectively. The group that showed better results for removing filling materials was the ProTaper Universal System for retreatment files, whereas the group of ProFile rotary instruments yielded better root canal cleanliness than the hand instruments, even though there was no statistically significant difference. The ProTaper Universal System for retreatment and ProFile rotary instruments worked significantly faster than the K-file. The ProTaper Universal System for retreatment files left cleaner root canal walls than the K-file hand instruments and the ProFile Rotary instruments, although none of the devices used guaranteed complete removal of the filling materials. The rotary NiTi system proved to be faster than hand instruments in removing root filling materials.

Effectiveness of ProTaper Universal retreatment instruments used with rotary or reciprocating adaptive motion in the removal of root canal filling material.

PubMed

Capar, I D; Arslan, H; Ertas, H; Gök, T; Saygılı, G

2015-01-01

To compare the effectiveness of ProTaper Universal retreatment instruments with continuous rotation and adaptive motion (AM; a modified reciprocating motion that combines rotational and reciprocating motion) in the removal of filling material. Mesiobuccal root canals in 36 mandibular first molars were instrumented up to size F2 with the ProTaper Universal instrument (Dentsply Maillefer, Ballaigues, Switzerland) and filled using sealer and ProTaper Universal F2 gutta-percha cones. Gutta-percha was then down-packed and the root canal backfilled using the extruder hand-piece of the Elements Obturation System (SybronEndo, Orange, CA, USA). The teeth were assigned to two groups (n = 18), and removal of the root fillings was performed using one of the following techniques: group 1) ProTaper Universal retreatment files used with rotational motion (RM) and group 2) ProTaper Universal retreatment files used with adaptive motion (AM) (600° clockwise/0° counter-clockwise to 370° clockwise/50° counter-clockwise). The teeth were sectioned, and both halves were analysed at 8 × magnification. The percentage of remaining filling material was recorded. The data were analysed statistically using the Student's t-test at a 95% confidence level (P < 0.05). There was no significant difference between the groups with respect to the total time required for retreatment (P = 0.481). The AM technique left significantly less filling material than the RM method (P = 0.013). The use of ProTaper Universal retreatment files with adaptive motion removed more filling materials from root canals than the rotational movement. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Fracture Resistance of Retreated Roots Using Different Retreatment Systems

PubMed Central

Er, Kursat; Tasdemir, Tamer; Siso, Seyda Herguner; Celik, Davut; Cora, Sabri

2011-01-01

Objectives: This study was designed to evaluate the fracture resistance of retreated roots using different rotary retreatment systems. Methods: Forty eight freshly extracted human canine teeth with single straight root canals were instrumented sequentially increasing from size 30 to a size 55 using K-files whit a stepback technique. The teeth were randomly divided into three experimental and one control groups of 12 specimens each. The root canals were filled using cold lateral compaction of gutta-percha and AH Plus (Dentsply Detrey, Konstanz, Germany) sealer in experimental groups. Removal of gutta-percha was performed with the following devices and techniques: ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland), R-Endo (Micro-Mega, Besançon, France), and Mtwo (Sweden & Martina, Padova, Italy) rotary retreatment systems. Control group specimens were only instrumented, not filled or retreated. The specimens were then mounted in copper rings, were filled with a self-curing polymethylmethacrylate resin, and the force required to cause vertical root fracture was measured using a universal testing device. The force of fracture of the roots was recorded and the results in the various groups were compared. Statistical analysis was accomplished by one-way ANOVA and a post hoc Tukey tests. Results: There were statistically significant differences between the control and experimental groups (P<.05). However, there were no significant differences among the experimental groups. Conclusions: Based on the results, all rotary retreatment techniques used in this in vitro study produced similar root weakness. PMID:21912497

Sealing ability of lateral compaction and tapered single cone gutta-percha techniques in root canals prepared with stainless steel and rotary nickel titanium instruments.

PubMed

Koçak, Mustafa M; Darendeliler-Yaman, Sis

2012-07-01

The aim of this study was to evaluate the sealing ability of lateral compaction and tapered single cone gutta-percha techniques in root canals prepared with stainless steel and rotary nickel titanium root canal instruments by fluid filtration method. The root canals were prepared with stainless steel (SS) and nickel titanium (NiTi) instruments. The canals prepared with SS were obturated with lateral compaction technique using .02 tapered cones and the canals prepared with NiTi instruments were obturated with lateral compaction technique using .02 tapered cones or 06 tapered single cones. The amount of leakage was evaluated by fluid filtration model. The results were statistically analyzed with one-way ANOVA. The group prepared with NiTi instruments and filled with lateral compaction technique showed significantly less coronal leakage than the group prepared with SS instruments and filled with lateral compaction technique (p<0.05). There was no statistically difference between apical leakages of groups (p>0.05). Obturation with lateral compaction of gutta-percha provides a superior coronal seal whilst canal instrumentation with engine-driven NiTi files reduces the extent of microleakage in root canals when compared with stainless steel hand instruments. Tapered single cone technique was comparable with lateral compaction technique because of easier application. Key words:Apical leakage, coronal leakage, lateral compaction technique, single cone technique.

Efficacy of ProTaper retreatment system in root canals filled with gutta-percha and two endodontic sealers.

PubMed

Só, Marcus Vinícius Reis; Saran, Caroline; Magro, Miriam Lago; Vier-Pelisser, Fabiana Vieira; Munhoz, Marcelo

2008-10-01

This study evaluated the efficacy of ProTaper Universal rotary retreatment system and hand files for filling material removal during retreatment and the influence of sealer type on the presence of filling debris in the reinstrumented canals. The canals of 60 palatal roots of first molars were obturated with gutta-percha and either a zinc oxide-eugenol-based or a resin-based sealer and reinstrumented: G1, EndoFill/hand files; G2, AH Plus/hand files; G3, EndoFill/ProTaper; G4, AH Plus/ProTaper. Roots were cleaved and examined with an optical microscope, and the amount of filling debris on canal walls was analyzed on digitized images. There was no significant difference (P > .05) among the root canal thirds within each group. G3 presented significantly more filling debris than G1 in the cervical third (P = .04). In the middle third, G2/G3/G4 showed more debris than G1 (P = .03). The techniques were similar (P = .64) in the apical third. All groups presented filling debris in the 3 canal thirds after reinstrumentation.

Effect of Post Space Preparation on Apical Obturation Quality of Teeth Obturated with Different Techniques: A Micro-computed Tomographic Study.

PubMed

Küçükkaya Eren, Selen; Askerbeyli Örs, Sevinc; Yılmaz, Zeliha

2017-07-01

The purpose of this study was to evaluate the obturation quality of root canals filled with different techniques and to determine whether post space preparation had an effect on the quality of apical obturation using micro-computed tomographic (micro-CT) imaging. The root canals of 30 human mandibular premolar teeth were instrumented, and the specimens were divided into 3 groups according to the obturation technique used: cold lateral compaction (CLC), warm vertical compaction (WVC), or single-cone (SC) techniques. The specimens were stored at 37°C and 100% humidity for 1 week. Then, the coronal root filling material was removed in order to create a post space. Micro-CT scans were performed before and after post space preparation for the volumetric analysis of voids and filling materials. Data were analyzed using repeated-measures analysis of variance and Bonferroni tests. The CLC and SC groups showed a significantly greater percentage volume of voids than the WVC group (P < .05), whereas no significant difference was found between the CLC and SC groups before and after post space preparation (P > .05). The post space preparation caused a significant increase in the percentage volume of voids in the CLC and SC groups (P < .05). No significant difference was detected in the percentage volume of voids in the WVC group after post space preparation (P > .05). No root fillings were void free. The WVC group presented the best obturation quality. The post space preparation negatively influenced the apical integrity of the filling materials in the CLC and SC groups, whereas it had no significant effect in the WVC group. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Analysis of the gutta-percha filled area in C-shaped mandibular molars obturated with a modified MicroSeal technique.

PubMed

Ordinola-Zapata, R; Bramante, C M; de Moraes, I G; Bernardineli, N; Garcia, R B; Gutmann, J L

2009-03-01

To analyse the gutta-percha filled area of C-shaped molar teeth root filled with the modified MicroSeal technique with reference to the radiographic features and the C-shaped canal configuration. Twenty-three mandibular second molar teeth with C-shaped roots were classified according to their radiographic features as: type I--merging, type II--symmetrical and type III--asymmetrical. The canals were root filled using a modified technique of the MicroSeal system. Horizontal sections at intervals of 600 mum were made 1 mm from the apex to the subpulpal floor level. The percentage of gutta-percha area from the apical, middle and coronal levels of the radiographic types was analysed using the Kruskal-Wallis test. Complementary analysis of the C-shaped canal configurations (C1, C2 and C3) determined from cross-sections from the apical third was performed in a similar way. No significant differences were found between the radiographic types in terms of the percentage of gutta-percha area at any level (P > 0.05): apical third, type I: 77.04%, II: 70.48% and III: 77.13%, middle third, type I: 95.72%, II: 93.17%, III: 91.13% and coronal level, type I: 98.30%, II: 98.25%, III: 97.14%. Overall, the percentage of the filling material was lower in the apical third (P < 0.05). No significant differences were found between the C-shaped canal configurations apically; C1: 72.64%, C2: 79.62%, C3: 73.51% (P > 0.05). The percentage of area filled with gutta-percha was similar in the three radiographic types and canal configuration categories of C-shaped molars. These results show the difficulty of achieving predictable filling of the root canal system when this anatomical variation exists. In general, the apical third was less completely filled.

Stress distributions in internal resorption cavities restored with different materials at different root levels: A finite element analysis study.

PubMed

Aslan, Tuğrul; Üstün, Yakup; Esim, Emir

2018-04-15

The aim of this study was to evaluate the stresses within simulated roots with internal resorption cavities at the apical, middle and coronal root levels, after obturation with gutta-percha and/or MTA utilising finite element analysis (FEA). Mandibular premolar teeth with internal resorption cavities at different root levels were modelled. Models were restored with gutta-percha and/or MTA. An oblique force of 300 N was applied and stress evaluations were carried out. In the MTA-filled resorption models, the stresses were distributed more homogeneously than the gutta-percha filled models, and the stress concentrations were lower in the remaining dentinal tissues. If the whole root is considered, the fully gutta-percha-filled models generated the highest stress values. Differences between the fully MTA-filled models and hybrid techniques were present only in the apical resorption models. Both the MTA and combination of MTA and gutta-percha can be suggested for use in clinical practice, in cases of internal root resorption cavity obturation. © 2018 Australian Society of Endodontology Inc.

A Novel Method for Characterizing Beam Hardening Artifacts in Cone-beam Computed Tomographic Images.

PubMed

Fox, Aaron; Basrani, Bettina; Kishen, Anil; Lam, Ernest W N

2018-05-01

The beam hardening (BH) artifact produced by root filling materials in cone-beam computed tomographic (CBCT) images is influenced by their radiologic K absorption edge values. The purpose of this study was to describe a novel technique to characterize BH artifacts in CBCT images produced by 3 root canal filling materials and to evaluate the effects of a zirconium (Zr)-based root filling material with a lower K edge (17.99 keV) on the production of BH artifacts. The palatal root canals of 3 phantom model teeth were prepared and root filled with gutta-percha (GP), a Zr root filling material, and calcium hydroxide paste. Each phantom tooth was individually imaged using the CS 9000 CBCT unit (Carestream, Atlanta, GA). The "light" and "dark" components of the BH artifacts were quantified separately using ImageJ software (National Institutes of Health, Bethesda, MD) in 3 regions of the root. Mixed-design analysis of variance was used to evaluate differences in the artifact area for the light and dark elements of the BH artifacts. A statistically significant difference in the area of the dark portion of the BH artifact was found between all fill materials and in all regions of the phantom tooth root (P < .05). GP generated a significantly greater dark but not light artifact area compared with Zr (P < .05). Moreover, statistically significant differences between the areas of both the light and dark artifacts were observed within all regions of the tooth root, with the greatest artifact being generated in the coronal third of the root (P < .001). Root canal filling materials with lower K edge material properties reduce BH artifacts along the entire length of the root canal and reduce the contribution of the dark artifact. Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

An improved technique for taking hydraulic conductivity cores from forest soils

Treesearch

Gerald M. Aubertin

1969-01-01

Describes a large-diameter, heavy-duty soil sampler that makes it possible to obtain long, relatively undisturbed sample columns from stony, root-filled forest soils. The resultant samples include the roots, root channels, stones, and macro-voids common to forested soils.

Apical and periapical repair of dogs' teeth with periapical lesions after endodontic treatment with different root canal sealers.

PubMed

Leonardo, Mário Roberto; Salgado, Antônio Alberto; da Silva, Léa Assed; Tanomaru Filho, Mário

2003-01-01

The aim of this study was to evaluate the apical and periapical repair after root canal treatment of dogs' teeth with pulp necrosis and chronic periapical lesion using different root canal sealers. After periapical lesion induction, forty-four root canals of 3 dogs were submitted to biomechanical preparation using 5.25% sodium hypochlorite as an irrigating solution. A calcium hydroxide dressing (Calen PMCC) was applied for 15 days and the root canals were filled using the lateral condensation technique with gutta-percha points and Sealapex, AH Plus or Sealer Plus for sealing. After 180 days, the animals were sacrificed by anesthetic overdose and the obtained histological sections were stained with hematoxylin-eosin for optical microscopic analysis of the apical and periapical repair. The groups filled with Sealapex and AH Plus had better histological repair (p < 0.05) than the group filled with Sealer Plus, that had unsatisfactory results.

Effects of ultrasonic root-end cavity preparation with different surgical-tips and at different power-settings on glucose-leakage of root-end filling material.

PubMed

Gunes, Betul; Aydinbelge, Hale Ali

2014-09-01

The aim of this in vitro study was to evaluate the effects of different ultrasonic surgical-tips and power-settings on micro-leakage of root-end filling material. The root canals were instrumented using rotary-files and were filled with tapered gutta-percha and root canal sealer using a single-cone technique. The apical 3 mm of each root was resected and the roots were divided into six experimental groups; negative and positive control groups. Root-end cavities were prepared with diamond-coated, zirconum-nitride-coated and stainless-steel ultrasonic retro-tips at half-power and high-power settings. The time required to prepare the root-end cavities for each group was recorded. Root-end cavities were filled with Super-EBA. Leakage values of all samples evaluated with glucose penetration method on 7, 14, 21 and 28(th) days. The results were statistically analyzed with Kruskal-Wallis and Hollander-Wolfe tests. The mean time required to prepare retro cavities using diamond-coated surgical tip at high-power setting was significantly less than other groups (P < 0.01). There were no statistically significant differences in the glucose penetration between the groups at first and second weeks (P > 0.01). Diamond-coated surgical tip showed the least leakage at high-power setting at 3(rd) and 4(th) weeks (P < 0.01). Under the conditions of this study, cavity preparation time was the shortest and the leakage of the root-end filling was the least when diamond-coated retro-tip used at high-power setting.

Bacterial killing by several root filling materials and methods in an ex vivo infected root canal model.

PubMed

Özcan, E; Eldeniz, A U; Arı, H

2011-12-01

To evaluate the ability of two root canal sealers (Epoxy resin-based AH Plus or polydimethylsiloxane-based GuttaFlow) and five root filling techniques (continuous wave of condensation, Thermafil, lateral condensation, matched taper single gutta-percha point, laterally condensed-matched taper gutta-percha point) to kill bacteria in experimentally infected dentinal tubules. An infected dentine block model was used. One hundred and twenty extracted, single-rooted human teeth were randomly divided into 10 test (n = 10) and 2 control (n = 10) groups. The roots, except negative controls, were infected with Enterococcus faecalis for 21 days. The root canals were then filled using the test materials and methods. Positive controls were not filled. Sterile roots were used as negative controls. Dentine powder was obtained from all root canals using gates glidden drills using a standard method. The dentine powder was diluted and inoculated into bacterial growth media. Total colony-forming units (CFU) were calculated for each sample. Statistical analysis was performed using the Kruskal-Wallis and Mann-Whitney U test. The epoxy resin-based sealer was effective in killing E. faecalis except when using Thermafil (P < 0.05), but the polydimethylsiloxane-based sealer was not effective in killing this microorganism except in the continuous wave group (P < 0.05). In the test model, AH Plus killed bacteria in infected dentine more effectively than GuttaFlow. The filling method was less important than the sealer material. © 2011 International Endodontic Journal.

Evaluation of canal filling after using two warm vertical gutta-percha compaction techniques in vivo: a preliminary study.

PubMed

Venturi, M

2006-07-01

To evaluate the quality of root canal filling when comparing two warm gutta-percha filling techniques in vivo. Human teeth were randomly divided into two equal groups, with 30 canals each. The root canals were shaped by hand and ProFile 0.04 rotary instruments to size 20-40 at the end-point and then filled with gutta-percha cones and AH-Plus. In group A, a traditional warm vertical compaction technique was performed using the Touch'n Heat, and back-filling with the Obtura II. In group B, a modified warm vertical compaction technique was used: small amounts of gutta-percha were removed, and the remaining most apical 3 mm were compacted with a 1 mm movement; then thermomechanical back-filling was performed. The teeth were extracted, stored in dye, cleared, and the distance between the apex and apical limit of the filling, linear dye penetration, and voids were measured from the buccal, lingual, mesial and distal perspective. The homogeneity of variance and means was verified using Levene's test and t-test. ANOVA and Dunnett post hoc test were used to establish the significance and to analyse the effects through multiple comparisons. Compared with the specimens of group A, the specimens of group B exhibited less mean linear dye penetration (P < 0.05), smaller void length (P < or = 0.05) and maximal width (P < or = 0.05) when examined in all four views, and a more precise filling when viewed from the buccal aspect (P < 0.05). The modified warm vertical compaction technique with apical back-filling produced a more effective and precise three-dimensional filling.

Micro-CT and nano-CT analysis of filling quality of three different endodontic sealers.

PubMed

Huang, Yan; Celikten, Berkan; de Faria Vasconcelos, Karla; Ferreira Pinheiro Nicolielo, Laura; Lippiatt, Nicholas; Buyuksungur, Arda; Jacobs, Reinhilde; Orhan, Kaan

2017-12-01

To investigate voids in different root canal sealers using micro-CT and nano-CT, and to explore the feasibility of using nano-CT for quantitative analysis of sealer filling quality. 30 extracted mandibular central incisors were randomly assigned into three groups according to the applied root canal sealers (Total BC Sealer, Sure Seal Root, AH Plus) by the single cone technique. Subsequently, micro-CT and nano-CT were performed to analyse the incidence rate of voids, void fraction, void volume and their distribution in each sample. Micro-CT evaluation showed no significant difference among sealers for the incidence rate of voids or void fraction in the whole filling materials (p > 0.05), whereas a significant difference was found between AH Plus and the other two sealers using nano-CT (p < 0.05). All three sealers presented less void volume in the apical third; however, higher void volumes were observed in the apical and coronal thirds in AH Plus using micro-CT (p < 0.05), while nano-CT results displayed higher void volume in AH Plus among all the sealers and regions (p < 0.05). Bioactive sealers showed higher root filling rate, lower incidence rate of voids, void fraction and void volume than AH Plus under nano-CT analysis, when round root canals were treated by the single cone technique. The disparate results suggest that the higher resolution of nano-CT have a greater ability of distinguishing internal porosity, and therefore suggesting the potential use of nano-CT in quantitative analysis of filling quality of sealers.

Cleaning efficacy of reciprocal and rotary systems in the removal of root canal filling material

PubMed Central

Koçak, Mustafa Murat; Koçak, Sibel; Türker, Sevinç Aktemur; Sağlam, Baran Can

2016-01-01

Aim: The aim of this study was to compare the efficacy of hand file, nickel titanium rotary instrument, and two reciprocating instruments for removing gutta-percha and sealer from the root canals. Materials and Methods: Eighty-eight mandibular premolar teeth were used. The root canals were shaped and filled with gutta-percha and a resin-based sealer. The specimens were divided into four groups according to the technique by which the root filling material was removed: Group 1 — Wave One; Group 2 — Reciproc; Group 3 — ProTaper; and Group 4 — Gates-Glidden burs and stainless steel hand file. Then teeth were split longitudinally and photographed. The images were transferred to a computer. The ratio of remaining filling material to the root canal periphery was calculated with the aid of ImageJ software. Statistical analysis was performed using Kruskal–Wallis and Mann–Whitney tests. Results: A significant difference was found among all groups (P < 0.001). The WaveOne group demonstrated significantly less remaining filling material. The greatest amount of filling material was found in specimens where gutta-percha was removed with Gates-Glidden burs and stainless steel hand file. Conclusion: The reciprocating files were found to be significantly more effective in removing the filling material from the canal walls compared to the rotational file and hand file. PMID:27099429

[Iatrogenic risks during the obturation of the root canal system].

PubMed

Aesaert, G

2000-01-01

A hermetic seal is the main goal of obturation of the root canal system. For that purpose guttapercha still remains the filling material of choice. Most filling techniques use plasticized guttapercha and a condensation technique to fulfil the requirements of hermetic seal. The heat to plasticize and the forces applied to condense that material may have an influence on the periodontal ligament and/or the remaining tooth structure. Furthermore can overfilling of guttapercha and more likely the sealer, affect the periodontal tissue. Although rare, mandibular nerve damage and adverse effects on the sinus maxillaris can be the result of inadequate treatment.

The influence of filling technique on depth of tubule penetration by root canal sealer: a study using light microscopy and digital image processing.

PubMed

De Deus, Gustavo A; Gurgel-Filho, Eduardo Diogo; Maniglia-Ferreira, Cláudio; Coutinho-Filho, Tauby

2004-04-01

The purpose of this study was to compare the depth of sealer penetration into dentinal tubules by three root-filling techniques using light microscopy and digital image processing. Thirty-two maxillary central incisors were prepared. Two teeth were separated for the control group. The rest were divided into three equal groups and obturated as following--G1: lateral condensation; G2: warm vertical compaction of gutta-percha and G3: Thermafil system. Each sample was sectioned longitudinally and prepared for microscopic analysis. A sequence of photomicrographs with magnifications of X50, X200 and X500 were taken. Through digital image analysis and processing, measurements for each field were obtained. A non-parametric ANOVA Kruskal-Wallis analysis was used to determine whether there were significant differences among the groups. Significant differences between G2 and G1 (p = 0.034) and between G3 and G1 (p = 0.021) were identified. There were no significant differences between G2 and G3 (p > 0.05). The results of this research suggest that samples root-filled by thermoplasticised gutta-percha techniques lead to deeper penetration of the root canal sealer into the dentinal tubules.

Radiographic technical quality of root canal treatment performed ex vivo by dental students at Valencia University Medical and Dental School, Spain

PubMed Central

Faus-Matoses, Vicente; Alegre-Domingo, Teresa; Faus-Llácer, Vicente J.

2014-01-01

Objectives: To evaluate radiographically the quality of root canal fillings and compare manual and rotary preparation performed on extracted teeth by undergraduate dental students. Study Design: A total of 561 premolars and molars extracted teeth were prepared using nickel-titanium rotary files or manual instrumentation and filled with gutta-percha using a cold lateral condensation technique, by 4th grade undergraduate students. Periapical radiographs were used to assess the technical quality of the root canal filling, evaluating three variables: length, density and taper. These data were recorded, scored and used to study the “technical success rate” and the “overall score”. The length of each root canal filling was classified as acceptable, short and overfilled, based on their relationship with the radiographic apex. Density and taper of filling were evaluated based on the presence of voids and the uniform tapering of the filling, respectively. Statistical analysis was used to evaluate the quality of root canal treatment, considering p < 0.05 as a statistical significant level. Results: The percentage of technical success was 44% and the overall score was 7.8 out of 10. Technical success and overall score were greater with rotary instruments (52% against 28% with a manual one, p < 0.001; 8.3 against 6.7 respectively, p < 0.001). Conclusions: It appears that inexperienced operators perform better root canal treatment (RCT) with the use of rotary instrumentation. Key words:Dental education, endodontics, rotary instrumentation, radiographs, root canal treatment, undergraduate students. PMID:24121911

Influence of apical patency and filling material on healing process of dogs' teeth with vital pulp after root canal therapy.

PubMed

Holland, Roberto; Sant'Anna Júnior, Arnaldo; Souza, Valdir de; Dezan Junior, Eloi; Otoboni Filho, José Arlindo; Bernabé, Pedro Felício Estrada; Nery, Mauro Juvenal; Murata, Sueli Satomi

2005-01-01

The purpose of this study was to investigate the periapical healing process of dogs' teeth with or without apical patency and after root canal filling with two types of sealers. Forty roots of premolars and incisors were utilized. The root canals were over-instrumented and dressed with a corticosteroid-antibiotic solution for 7 days to obtain ingrowth of periapical connective tissue into the canals. After this period, the tissue was removed in half of the specimens (groups with patency) and preserved in the other half (groups without patency). Canals were filled by lateral condensation technique with gutta-percha points and either a calcium hydroxide-based sealer (Sealer Plus) or a Grossman's cement (Fill Canal). The animals were killed by anesthetic overdose 60 days after the endodontic treatment and anatomic pieces were obtained and prepared for histologic examination. Data were evaluated in a blind analysis on the basis of several histomorphologic parameters. The groups without patency had better results (p=0.01) than those in which the ingrown connective tissue was removed. Comparing the sealers, Sealer Plus had significantly better results (p=0.01) than Fill Canal. In conclusion, both the apical patency (presence or absence) and the type of root canal filling material influenced the periapical healing process in dogs' teeth with vital pulp after root canal treatment. The use of a calcium hydroxide-based sealer in teeth without apical patency yielded the best results among the experimental conditions proposed.

A comparison of MTA, Super-EBA, composite and amalgam as root-end filling materials using a bacterial microleakage model.

PubMed

Adamo, H L; Buruiana, R; Schertzer, L; Boylan, R J

1999-05-01

The aim of this study was to compare traditional and newly developed root-end filling materials for resistance to bacterial microleakage. Sixty extracted single-rooted teeth were randomly divided into five groups for root-end filling with mineral trioxide aggregate, Super-EBA, TPH composite resin with ProBond dentine bonding agent, Dispersalloy amalgam with and without ProBond, and positive and negative control groups. Root canals were instrumented using the step-back technique and simulated root-end resections performed. Root-end filling materials were placed in 3 mm ultrasonic retropreparations. Nail varnish was applied to all external root surfaces to the level of the resected root ends to prevent lateral microleakage. Samples were sterilized in an ethylene oxide sterilizer for 12 h. Using a newly designed model system, the apical 3-4 mm of the roots were immersed in BHI culture medium with phenol red indicator within culture chambers. The coronal access of each specimen was inoculated every 48 h with a suspension of Streptococcus salivarius. Culture media were observed every 24 h for colour change indicating bacterial contamination. Media demonstrating colour change were plated for S. salivarius. Samples were observed for 12 weeks. At 4 weeks 10% of specimens from each experimental group had evidence of leakage. At 8 weeks 20% of specimens filled with amalgam without dentine bonding agent, Super-EBA and MTA had evidence of leakage. At 12 weeks minor differences between materials were noted. Under the conditions of the study, despite some variations, there were no statistically significant differences in rate of microleakage among the five groups tested at either 4, 8 or 12 weeks.

An innovative approach for rubber dam isolation of root end tip: A case report.

PubMed

Mittal, Sunandan; Kumar, Tarun; Mittal, Shifali; Sharma, Jyotika

2015-01-01

The success of an apicoectomy with a retrofilling is dependent upon obtaining an acceptable apical seal. The placement of the variously approved retrograde materials requires adequate access, visibility, lighting, and a sterile dry environment. There are instances, however, in which it is difficult to use the rubber dam. One such instance is during retrograde filling. This case report highlights an innovative technique for rubber dam isolation of root end retrograde filling.

Radiologic assessment of quality of root canal fillings and periapical status in an Austrian subpopulation – An observational study

PubMed Central

Frank, Wilhelm; Madaus, Theresa

2017-01-01

Background/Objective Progress in endodontic techniques and methodological advances have altered root canal therapy over the last decades. These techniques and methods need periodical documentation. This observational study determined the current prevalence of endodontic treatments, and investigated the relationship of various factors with the periapical status in a Lower Austrian subpopulation. Methodology One thousand orthopantomograms of first-time university adult patients radiographed at an outpatient clinic were evaluated. For each tooth, the presence of periradicular pathosis and/or endodontic treatment was recorded, as was the quality of (post-)endodontic treatment (homogeneity and length of root canal fillings; preparation failures; posts/screws; apicoectomies; coronal restorations). Two evaluators, blinded to each other, scored all teeth. In cases of disagreement, they joined for a consensus score. Results In all, 22,586 teeth were counted. Of these, 2,907 teeth (12.9%) had periapical pathosis, while 2,504 teeth had undergone root canal treatment. Of the endodontically treated teeth, 52% showed no radiographic signs of apical periodontitis, while 44.9% had overt apical lesions, and 3,1% revealed widened periodontal ligament space. The majority of the root canal fillings was inhomogeneous (70.4%); 75.4% were rated too short, and 3.8% too long. The presence of apical pathosis was significantly correlated (odds ratio (OR) 2.556 [confidence interval (CI) 2.076–3.146]; P<0.0001) with poor root canal fillings (length and homogeneity). Posts or screws positively affected periapical status (OR 1.853 [CI 1.219–2.819]; P = 0.004), but endodontically treated posterior teeth were infrequently restored (posts, 7.5%; screws, 2.7%). Best results were found for teeth with both appropriate endodontic treatment and adequate coronal restoration. Conclusion A high prevalence of periradicular radiolucencies was observed with root canal filled teeth, along with high numbers of unmet treatment needs. Periapical health was associated with adequate root canal obturation and high-grade postendodontic restorations, and quality regarding these latter aspects is considered mandatory to promote periapical health. PMID:28464019

Efficacy of reciprocating and rotary NiTi instruments for retreatment of curved root canals assessed by micro-CT.

PubMed

Rödig, T; Reicherts, P; Konietschke, F; Dullin, C; Hahn, W; Hülsmann, M

2014-10-01

To compare the efficacy of reciprocating and rotary NiTi-instruments in removing filling material from curved root canals using micro-computed tomography. Sixty curved root canals were prepared and filled with gutta-percha and sealer. After determination of root canal curvatures and radii in two directions as well as volumes of filling material, the teeth were assigned to three comparable groups (n = 20). Retreatment was performed using Reciproc, ProTaper Universal Retreatment or Hedström files. Percentages of residual filling material and dentine removal were assessed using micro-CT imaging. Working time and procedural errors were recorded. Statistical analysis was performed by variance procedures. No significant differences amongst the three retreatment techniques concerning residual filling material were detected (P > 0.05). Hedström files removed significantly more dentine than ProTaper Universal Retreatment (P < 0.05), but the difference concerning dentine removal between both NiTi systems was not significant (P > 0.05). Reciproc and ProTaper Universal Retreatment were significantly faster than Hedström files (P = 0.0001). No procedural errors such as instrument fracture, blockage, ledging or perforation were detected for Hedström files. Three perforations were recorded for ProTaper Universal Retreatment, and in both NiTi groups, one instrument fracture occured. Remnants of filling material were observed in all samples with no significant differences between the three techniques. Hedström files removed significantly more dentine than ProTaper Universal Retreatment, but no significant differences between both NiTi systems were detected. Procedural errors were observed with ProTaper Universal Retreatment and Reciproc. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Clinical microscopic analysis of ProTaper retreatment system efficacy considering root canal thirds using three endodontic sealers.

PubMed

Só, Marcus Vinícius Reis; De Figueiredo, Jose Antônio Poli; Freitas Fachin, Elaine Vianna; Húngaro Duarte, Marco Antônio; Pereira, Jefferson Ricardo; Kuga, Milton Carlos; Da Rosa, Ricardo Abreu

2012-09-01

To evaluate the efficacy of ProTaper Universal rotary retreatment system and the influence of sealer type on the presence of filling debris in the reinstrumented canals viewed in an operative clinical microscope. Forty-five palatal root canals of first molars were filled with gutta-percha and one of the following sealers: G1, EndoFill; G2, AH Plus; G3, Sealapex. The canals were then reinstrumented with ProTaper Universal rotary system. Roots were longitudinally sectioned and examined under an operative clinical microscope (10×), and the amount of filling debris on canal walls was analyzed using the AutoCAD 2004 software. A single operator used a specific software tool to outline the canal area and the filling debris area in each third (cervical, middle, and apical), as well as the total canal area. Data were analyzed by Kruskal-Wallis test and Tukey test at P < 0.05. Sealapex demonstrated significant differences in the average of filling debris area/canal among the 3 thirds. This group revealed that apical third showed more debris than the both cervical and middle third (P < 0.0001). Endofill presented significantly more filling debris than Sealapex in the cervical third (P < 0.05). In the middle (P = 0.12) and apical third (P = 0.10), there were no differences amongst groups. Debris was left in all canal thirds, regardless of the retreatment technique. The greatest differences between techniques and sealers were found in the cervical third. Copyright © 2012 Wiley Periodicals, Inc.

Postoperative pain after one-visit root-canal treatment on teeth with vital pulps: Comparison of three different obturation technique

PubMed Central

Alonso-Ezpeleta, Luis O.; Gasco-Garcia, Carmen; Castellanos-Cosano, Lizett; Martín-González, Jenifer; López-Frías, Francsico J.

2012-01-01

Objectives. To investigate and compare postoperative pain after one-visit root canal treatment (RCT) on teeth with vital pulps using three different obturation techniques. Study Design. Two hundred and four patients (105 men and 99 women) aged 12 to 77 years were randomly assigned into three treatments groups: cold lateral compaction of gutta-percha (LC), Thermafil technique (TT), and Backfill - Thermafil obturation technique (BT). Postoperative pain was recorded on a visual analogue scale (VAS) of 0 - 10 after 2 and 6 hours, and 1, 2, 3, 4, 5, 6 and 7 days. Data were statistically analyzed using multivariate logistic regression analysis. Results. In the total sample, 87% of patients experienced discomfort or pain in some moment between RCT and the seventh day. The discomfort experienced was weak, light, moderate and intense in 6%, 44%, 20% and 6% of the cases, respectively. Mean pain levels were 0.4 ± 0.4, 0.4 ± 0.3, and 1.4 ± 0.7 in LC, BT, and TT groups, respectively. Patients of TT group experienced a significantly higher mean pain level compared to other two groups (p < 0.0001). In TT group, all patients felt some level of pain at six hours after RCT. Conclusions. Postoperative pain was significantly associated with the obturation technique used during root canal treatment. Patients whose teeth were filled with Thermafil obturators (TT technique) showed significantly higher levels of discomfort than patients whose teeth were filled using any of the other two techniques. Key words:Postoperative pain, root-canal obturation, root-canal treatment, Thermafil. PMID:22322522

Quality aspects of ex vivo root canal treatments done by undergraduate dental students using four different endodontic treatment systems.

PubMed

Jungnickel, Luise; Kruse, Casper; Vaeth, Michael; Kirkevang, Lise-Lotte

2018-04-01

To evaluate factors associated with treatment quality of ex vivo root canal treatments performed by undergraduate dental students using different endodontic treatment systems. Four students performed root canal treatment on 80 extracted human teeth using four endodontic treatment systems in designated treatment order following a Latin square design. Lateral seal and length of root canal fillings was radiographically assessed; for lateral seal, a graded visual scale was used. Treatment time was measured separately for access preparation, biomechanical root canal preparation, obturation and for the total procedure. Mishaps were registered. An ANOVA mirroring the Latin square design was performed. Use of machine-driven nickel-titanium systems resulted in overall better quality scores for lateral seal than use of the manual stainless-steel system. Among systems with machine-driven files, scores did not significantly differ. Use of machine-driven instruments resulted in shorter treatment time than manual instrumentation. Machine-driven systems with few files achieved shorter treatment times. With increasing number of treatments, root canal-filling quality increased, treatment time decreased; a learning curve was plotted. No root canal shaping file separated. The use of endodontic treatment systems with machine-driven files led to higher quality lateral seal compared to the manual system. The three contemporary machine-driven systems delivered comparable results regarding quality of root canal fillings; they were safe to use and provided a more efficient workflow than the manual technique. Increasing experience had a positive impact on the quality of root canal fillings while treatment time decreased.

Comparison of different techniques for obturating experimental internal resorptive cavities.

PubMed

Goldberg, F; Massone, E J; Esmoris, M; Alfie, D

2000-06-01

Forty extracted maxillary central incisors were instrumented at the working length to a #50 file. The roots were sectioned transversely with a diamond disk at 7 mm from the anatomical apex. At the opening of the root canal of each section, hemicircular cavities were drilled with a specially designed bur. The corresponding root sections were cemented with glue, thus obtaining root canals with similar cavities that simulated internal resorptions. Teeth were embedded in plaster casts to facilitate their handling. The specimens were randomly separated into four groups of 10. The following obturation techniques were evaluated: lateral compaction (group A), hybrid technique (group B), Obtura II (group C), and Thermafil (group D). AH26 was used as the sealer. After obturation, the plaster was removed and the teeth were radiographed in buccolingual and mesiodistal directions to evaluate the quality of the obturation at the IRC. The incisors were then cut with a scalpel at the same level as the previous section, to examine, under a stereomicroscope, the type of material that filled the IRC. Obtura II gave the best results and in most of the specimens obturated with this technique, the IRC were filled mainly with gutta-percha. Statistical analysis of the data indicated that the differences between group C and the other groups were significant (P < 0.05).

Influence of solvents on the bond strength of resin sealer to intraradicular dentin after retreatment.

PubMed

Palhais, Marcelo; Sousa-Neto, Manoel Damião; Rached-Junior, Fuad Jacob Abi; Amaral, Mariana Carvalho de Andrade; Alfredo, Edson; Miranda, Carlos Eduardo Saraiva; Silva-Sousa, Yara Teresinha Corrêa

2017-01-26

This study evaluated the removal of filling material with ProTaper Universal Rotary Retreatment system (PTR) combined with solvents and the influence of solvents on the bond strength (PBS) of sealer to intraradicular dentin after canal reobturation. Roots were endodontically treated and distributed to five groups (n = 12). The control group was not retreated. In the four experimental groups, canals were retreated with PTR alone or in combination with xylol, orange oil, and eucalyptol. After filling material removal, two specimens of each group were analysed by SEM and µCT to verify the presence of filling remnants on root canal walls. The other roots were reobturated and sectioned in 1-mm-thick dentin slices that were subjected to the push-out test. Data were analysed by two-way ANOVA and Tukey's test (α = 0.05). SEM and µCT analysis revealed that all retreatment techniques left filling remnants on canal walls. The control group (3.47 ± 1.21) presented significantly higher (p < 0.05) PBS than the experimental groups. The groups retreated with PTR alone (2.59 ± 0.99) or combined with xylol (2.54 ± 0.77) and orange oil (2.32 ± 0.93) presented similar bond strength (p > 0.05), and differed significantly from the group with eucalyptol (1.89 ± 0.63). The solvents reduced the PBS of the sealer to dentin and no retreatment technique promoted complete removal of filling material.

Effect of bulk-fill base material on fracture strength of root-filled teeth restored with laminate resin composite restorations.

PubMed

Taha, N A; Maghaireh, G A; Ghannam, A S; Palamara, J E

2017-08-01

To evaluate the effect of using a bulk-fill flowable base material on fracture strength and fracture patterns of root-filled maxillary premolars with MOD preparations restored with laminate restorations. Fifty extracted maxillary premolars were selected for the study. Standardized MOD cavities with endodontic treatment were prepared for all teeth, except for intact control. The teeth were divided randomly into five groups (n=10); (Group 1) sound teeth, (Group 2) unrestored teeth; (Group 3) MOD cavities with Vitrebond base and resin-based composite (Ceram. X One Universal); (Group 4) MOD cavities with 2mm GIC base (Fuji IX GP) and resin-based composite (Ceram. X One Universal) open laminate, (Group 5) MOD cavities were restored with 4mm of bulk-fill flowable base material (SDR) and resin-based composite (Ceram. X One Universal). All teeth were thermocycled and subjected to a 45° ramped oblique load in a universal testing machine. Fracture load and fracture patterns were recorded. Data were analyzed using one-way ANOVA and Dunnett's T3 test. Restoration in general increased the fracture strength compared to unrestored teeth. The fracture strength of group 5 (bulk-fill) was significantly higher than the fracture strength of the GIC laminate groups and not significantly different from the intact teeth (355±112N, P=0.118). The type of failure was unfavorable for most of the groups, with the majority being mixed failures. The use of a bulk-fill flowable base material significantly increased the fracture strength of extracted root-filled teeth with MOD cavities; however it did not improve fracture patterns to more favorable ones. Investigating restorative techniques that may improve the longevity of root-filled premolar teeth restored with direct resin restorations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Degradation of trans-polyisoprene after root filling with thermoplasticized techniques.

PubMed

Maniglia-Ferreira, C; Bönecker, G; Silva, J B A; de Paula, R C M; Feitosa, J P A; Souza-Filho, F J

2008-04-01

To evaluate ex vivo degradation of gutta-percha following six thermoplastic obturation techniques. Ninety human-extracted mandibular premolars were selected and divided randomly into nine groups for filling. Group 1: thermomechanical compaction for 3 s with Konne gutta-percha points (Konne Ind. e Com. de Mat. Odontol., Belo Horizonte, MG, Brazil); Group 2: thermomechanical compaction for 3 s with Dentsply TP gutta-percha points (Dentsply Indústria e Comércio Ltda, Petrópolis, R.J. Brazil); Group 3: thermomechanical compaction for 10 s with Konne; Group 4: thermomechanical compaction for 10 s with Dentsply TP; Group 5: warm vertical condensation using System B (EIE/Analytic, Richmond, WA, USA) with Konne; Group 6: warm vertical condensation using System B with Dentsply TP; Group 7: vertical condensation with Konne; Group 8: vertical condensation with Dentsply TP; Group 9: Microseal cone (Analytic Endodontics, Glendora, CA, USA). A further four groups were assessed without using teeth, Group 10: Microseal microflow (Analytic Endodontics); Group 11: Obtura (Obtura Corporation, Penton, MO, USA); Group 12: Obtura flow (Obtura Corporation); Group 13: Thermafil (Dentsply Maillefer, Tulsa, OK, USA). The filling material was removed from the root canal and trans-1,4-polyisoprene isolated by solubilization of the root filling remnants in chloroform followed by filtration and centrifugation. By gel permeation chromatography and infrared spectroscopy, the occurrence and degree of degradation were assessed. The results were analysed statistically using the Kruskal-Wallis test. With differential scanning calorimetry, the thermal behaviour of the gutta-percha was determined. A significant decrease in polymer molar mass and the production of carboxyl and hydroxyl groups in the polymer were observed with thermomechanical compaction used for 10 s and vertical condensation filling techniques (P = 0.0001 and P = 0.0005, respectively). Other techniques caused no polymer degradation. Polyisoprene degrades with high temperature. Thermomechanical compaction for 10 s and vertical condensation were associated with the greatest degradative process.

On implementation of an endodontic program.

PubMed

Koch, Margaretha

2013-01-01

It is widely accepted that the uptake of research findings by practitioners is unpredictable, yet until they are adopted, advances in technology and clinical research cannot improve health outcomes in patients. Despite extensive research there is limited knowledge of the processes by which changes occur and ways of measuring the effectiveness of change of practice. The overall aim of this thesis was to investigate aspects of an educational intervention in clinical endodontic routines and new instrumentation techniques in a Swedish County Public Dental Service. Special reference was made to the establishment of changed behaviour in practice, the process of change, and the clinical effects. Although a high level of competence in root canal treatment procedures is required in general dental practice, a number of Swedish studies have revealed inadequate root-fillings quality and associated periapical inflammation in general populations. It is suggested that the adoption of the nickel-titanium rotary instrumentation (NiTiR) technique would improve the cleaning and shaping of root canals and the quality of the root-filling. However, there is limited knowledge of the effectiveness of the technique when applied in general dental practice. In two of four consecutive studies, the subjects were employees of a county Public Dental Service. The aim was to investigate the rate of adoption of clinical routines and the NiTiR technique: the output, and the qualitative meaning of successful change in clinical practice. In the other two studies the aim was to investigate treatment effect and the cost-effectiveness of root canal treatment in a general population: the outcome. Four hundred employees (dentists, dental assistants, administrative assistants and clinical managers) of a Swedish County Public Dental Service were mandatorily enrolled in an educational and training program over two years. Change of practice was investigated in a post-education survey. The NiTiR technique was adopted by significantly more dentists in the intervention county compared to a control county (77% and 6% respectively). Dentists in the intervention county completed root canal instrumentation in significantly fewer sessions than the dentists in the control county. Eight in-depth interviews, two with each participant, (dentist, dental assistant, receptionist, clinical manager), were strategically selected for a phenomenological analysis. Four factors were identified as necessary for successful change: 1) disclosed motivation, 2) allowance for individual learning processes, 3) continuous professional collaboration, and 4) a facilitating educator. A random sample of 850 performed root canal treatments was used for a study of treatment outcome; 425 before and 425 after the education and adoption of the NiTiR technique. Root-filling quality, periapical status and tooth survival were assessed on radiographs taken at treatment and at follow-up, > or = 4 years later. Apical periodontitis was found in 34% of the teeth root-filled before the education compared to 33%, after. After the education, root-filling quality improved significantly, tooth survival was significantly higher, however, without a subsequent improvement in success rate post-education; 68% vs. 67%. A micro-costing model was used to calculate the costs of root canal instrumentation, pre- and post-education, in the same sample used in the study of treatment outcome. Costs were lower post-education: by SEK 264 for teeth with one canal and SEK 564 for teeth with three or more canals. A reason for lower costs was that the NiTiR technique dominated after the education and required significantly fewer instrumentation sessions. A cost-minimization analysis disclosed that root canal treatments undertaken post-education were more cost-effective. In conclusion, there was only a partial relationship between output and outcome. Although root-filling quality improved significantly, the study did not show any association between the more frequent use of NiTiR and an improvement in remaining teeth with normal periapical status or success rate. However, the use of NiTiR was more cost-effective. These results are in accordance with previous findings of the so called efficacy-effectiveness gap in clinical practice: a high output is not predictive of a high outcome. The overall conclusion to be drawn from these studies is that further research is warranted to identify factors associated with improvement of the quality of endodontic care. The general interpretation of the findings of these implementation studies is as important as the effects of the change in endodontic instrumentation: a clinically relevant and applicable intervention, introduced by experienced expertise under allowing learning and collaborating circumstances, disclosed clinicians' motivation and facilitated implementation. The finding of qualitative differences between the questionnaire responses and the in-depth interviews suggest that a critical approach is warranted when comparing surveys and qualitative methods aimed at investigating qualitative experiences of change, due to their different epistemological premises.

The efficacy of two rotary NiTi instruments and H-files to remove gutta-percha from root canals

PubMed Central

Akpınar, Kerem E.; Altunbaş, Demet

2012-01-01

Objective: The aim of this study was to evaluate the efficacy of R-Endo® and K3® rotary nickel-titanium instruments compared with manual instrumentation with H-files, with use of a solvent, for removal of gutta-percha during retreatment. Study design: Forty five freshly extracted human single-rooted teeth, each with one root canal, were instrumented with K-files and filled using cold lateral compaction of gutta-percha and AH 26® sealer. The teeth were randomly divided into three groups of 15 specimens each. Removal of gutta-percha was performed with the following devices and techniques: Group 1 (H-files), Group 2 (R-Endo®), and Group 3 (K3®). The specimens were rendered transparent for the evaluation of the area of remaining gutta-percha/sealer in buccolingual and mesiodistal directions. Statistical analysis as performed by using one-way ANOVA and Kruskal-Wallis tests (p=0.05). Results: All retreatment techniques used in this study left some filling material inside the root canal. Images in buccolingual and mesiodistal directions showed no significant differences between the groups (p>0.05). Conclusions: Under the experimental conditions, the remaining filling material after retreatment was similar for each group. Key words:Gutta-percha removal, K3®, NiTi, R-Endo®. PMID:22143729

A prospective, randomized, comparative clinical study of resin composite and glass ionomer cement for retrograde root filling.

PubMed

Jensen, S S; Nattestad, A; Egdø, P; Sewerin, I; Munksgaard, E C; Schou, S

2002-12-01

To compare the clinical and radiographic treatment outcome of retrograde root filling with either dentin-bonded resin composite (Retroplast, RP) or glass ionomer cement (Chelon-Silver, CS). A prospective, randomized clinical study of 134 consecutive patients with indication of retrograde root filling of an incisor, canine, premolar, or first molar. Either RP or CS was chosen at random as retrograde filling material. Either material was applied onto the entire resection surface after prepared slightly concave. This preparation technique makes a sealing of the entire resection surface possible and prevents marginal contraction gaps during polymerization. A total of 122 patients were available for 1-year follow-up. After 1 year the proportion of successful cases was significantly higher in the RP group (73%) than in the CS group (31%) (p<0.001). Doubtful healing with a need for a longer observation period was seen in 17% of the RP cases and 19% of the CS cases. The proportion of failures in the RP group (10%) was significantly lower than that in the CS group (50%) (p<0.001). Most of the unsuccessful CS cases failed due to loosening of the retrograde filling. Dentin-bonded RP applied onto the entire, slightly concave resection surface is a predictable apical sealant characterized by a high success rate. In contrast, retrograde root filling with CS results in an unacceptably high failure rate due to insufficient bonding strength to the concave resection surface.

Effect of photodynamic therapy (PDT) on Enterococcus faecalis biofilm in experimental primary and secondary endodontic infections.

PubMed

Tennert, Christian; Feldmann, Katharina; Haamann, Edwina; Al-Ahmad, Ali; Follo, Marie; Wrbas, Karl-Thomas; Hellwig, Elmar; Altenburger, Markus J

2014-11-04

To determine the antibacterial effect of photodynamic Therapy on Enterococcus faecalis (E. faecalis) biofilms in experimentally infected human root canals in primary infections and endodontic retreatments. One hundred and sixty single-rooted extracted teeth with one root canal were prepared using ProTaper instruments. Seventy specimens were left without root canal filling and autoclaved. The root canals of another 70 specimens were filled with Thermafil and AH Plus and the root canal fillings were removed after 24 hours using ProTaper D files and plasma sterilized. The specimens were infected with a clinical isolate of E. faecalis for 72 hours. Samples were taken using sterile paper points to determine the presence of E. faecalis in the root canals. The specimens were randomly divided into groups according to their treatment with 20 teeth each and a control. In the PDT group the teeth were treated using PDT, consisting of the photosensitizer toluidine blue and the PDT light source at 635 nm. In the NaOCl (sodium hypochlorite) group the root canals were rinsed with 10 mL of 3% NaOCl. In the NaOCl-PDT group the root canals were rinsed with 10 mL of 3% of sodium hypochlorite and then treated with PDT. Samples were taken after treatments using sterile paper points. Additionally, remaining root canal filling material was recovered from the root canal walls. Survival fractions of the samples were calculated by counting colony-forming units. A one-way analysis of variance (ANOVA) was applied to the data to assess the effect of different treatment techniques. Antimicrobial treatment of root canals caused a significant reduction of bacterial load in all groups. NaOCl irrigation eliminated E. faecalis most effectively. PDT alone was less effective compared to NaOCl irrigation and the combination of NaOCl irrigation and PDT. CFU levels recovered from the filling material after NaOCl irrigation of the root canals were 10fold higher compared to PDT and the combination of NaOCl irrigation and PDT. Photodynamic therapy killed E. faecalis in experimental primary endodontic infections and retreated human root canals. PDT is an effective supplement in root canal disinfection, especially in endodontic retreatments.

COMPARATIVE SEM EVALUATION OF THREE SOLVENTS USED IN ENDODONTIC RETREATMENT: AN EX VIVO STUDY

PubMed Central

Scelza, Miriam F. Zaccaro; Coil, Jeffrey M.; Maciel, Ana Carolina de Carvalho; Oliveira, Lílian Rachel L.; Scelza, Pantaleo

2008-01-01

This study compared, by scanning electron microscopy (SEM), the efficacy of three solvents on the removal of filling materials from dentinal tubules during endodontic retreatment. Forty human maxillary canines with straight canals were prepared according to a crown-down technique and enlarged to a#30 apical file size, before obturation with gutta-percha and a zinc-oxide-eugenol based sealer. The samples were stored for 3 months before being randomly assigned to four groups: chloroform (n=10), orange oil (n=10), eucalyptol (n=10) and control (n=10). Solvents were applied to a reservoir created on the coronal root third using Gates Glidden drills. The total time for retreatment using the solvents was 5 minutes per tooth. Following retreatment the roots were split longitudinally for SEM evaluation. SEM images were digitized, analyzed using Image ProPlus 4.5 software, and the number of dentinal tubules free of filling material from the middle and apical thirds was recorded. No significant difference was found among the solvent groups regarding the number of dentinal tubules free of root filling remnants in the middle and apical root thirds (p>0.05). However, the control group had fewer dentinal tubules free of filling material (p<0.05). Under the tested conditions, it may be concluded that there was no significant difference among the solvents used to obtain dentinal tubules free of filling material remnants. PMID:19089285

Micro-CT evaluation of the effectiveness of the combined use of rotary and hand instrumentation in removal of Resilon.

PubMed

Asheibi, Fatma; Qualtrough, Alison J E; Mellor, Anthony; Withers, Philip J; Lowe, Tristan

2014-01-01

This study compares the effectiveness of ProTaper rotary files with ProTaper retreatment and K-files in the removal of Resilon or gutta percha (GP) from canals filled either by cold lateral condensation or thermal obturation using micro-CT. Ninety-six teeth were prepared using ProTaper files and allocated into four groups (n=24): Group-1 was filled with GP/AH-Plus and Group-2 with Resilon/RealSeal using cold lateral condensation. Group-3 was filled with GP/AH-Plus and Group-4 with Resilon/RealSeal using System B and Obtura II. The roots were scanned by micro-CT. Each group was divided into two subgroups (n=12): A, retreated using ProTaper files and B, using ProTaper retreatment and K-files. The roots were scanned to calculate the volume of the remaining material. With thermal obturation, roots filled with Resilon had significantly more remaining material than GP. Obturation using thermal technique resulted in significantly less remaining material than cold condensation except Resilon retreated using ProTaper retreatment and K-files.

Sealing ability of white and gray mineral trioxide aggregate mixed with distilled water and 0.12% chlorhexidine gluconate as a root end filling material: an ex vivo evaluation.

PubMed

Shetty, K Harish Kumar; Prathap, M S; Prithviraj, K J

2013-01-01

The aim of this study was to evaluate the sealing ability of white and gray mineral trioxide aggregate (MTA) mixed with distilled water and 0.12% chlorhexidine (CHX) gluconate when used as a root-end filling material using the dye-penetration technique. A total of 48 single-rooted human teeth were cleaned, shaped, and obturated with gutta-percha and AH Plus sealer. The apical 3 mm of each root was resected, and 3-mm deep root-end cavity preparations were made. The teeth were randomly divided into 4 experimental groups, each containing 8 teeth, and 2 negative and positive control groups, each containing 8 teeth. Root-end cavities in the experimental groups were filled with the experimental materials. After application of nail polish, the teeth were exposed to India ink for 72 h and longitudinally sectioned, and the extent of dye penetration was measured with a stereomicroscope. No statistically significant differences were observed in the sealing ability of gray and white MTA mixed with distilled water and 0.12% CHX. CHX appears to be a good alternative to replace distilled water, as a solution to be mixed with MTA.

Periapical tissue healing after post space preparation with or without use of a protection plug and root canal exposure to the oral environment. Study in dogs.

PubMed

Holland, Roberto; Manne, Luciana Noronha; de Souza, Valdir; Murata, Sueli Satomi; Dezan Júnior, Eloi

2007-01-01

The purpose of this study was to evaluate the influence of coronal leakage on the healing of dogs' periapical tissues after root canal filling, post space preparation and protection or not with a temporary sealer plug. Forty root canals of dogs' teeth were instrumented and filled by the lateral condensation technique with gutta-percha points and Endomethasone or CRCS sealers. After post space preparation, the remaining filling material was protected or not with a plug of temporary Coltosol sealer and exposed to the oral environment for 90 days. Thereafter, the animals were sacrificed and the specimens were removed and prepared for histomorphological and histobacteriological analysis. The findings revealed 35% of microbial leakage in the groups without plugs and 15% of leakage in the groups with plugs. Statistical analysis showed that the use of a Coltosol plug improved significantly the histomorphological results regardless of the type of root canal sealer (p=0.05) and that CRCS and Endomethasone sealers showed similar results (p>0.05).

Influence of different final irrigation regimens and various endodontic filling materials on vertical root fracture resistance.

PubMed

Sungur, D D; Altundasar, E; Uzunoglu, E; Yilmaz, Z

2016-01-01

The aim of this study was to evaluate the influence of different endodontic materials and final irrigation regimens on vertical root fracture (VRF) resistance. Eighty human teeth were prepared then assigned into two groups (n = 40) according to the final irrigations. G1: 5 mL, 5.25% sodium hypochlorite (NaOCl), G2: 5 mL, 2% chlorhexidine gluconate (CHX). Each group was assigned into four subgroups according to the obturation system used (n = 10): A: iRoot SP/single gutta-percha cone (SGP), B: Only iRoot SP, C: Mineral trioxide aggregate (MTA)-Fillapex/SGP, D: AH26/SGP. The specimens were embedded in acrylic molds and subjected to compressive loading at a rate of 1 mm min until VRF occurred. Data were analyzed via three-way ANOVA tests. The statistically significant difference was found among groups (P < 0.05). The G1A and G1B and G1D revealed significantly higher-VRF values than G1C (P = 0.023). The roots filled with MTA-Fillapex revealed lower-VRF values than the other subgroups (P < 0.05). Groups irrigated with NaOCl had significantly lower-VRF values than the groups irrigated with CHX (P < 0.05). Final irrigation regimens could alter VRF resistance of root canals filled with different obturation technique and root canal sealers.

Study of the areas and thicknesses of mesiobucal root canals prepared by three endodontic techniques.

PubMed

Constante, Isa Geralda Teixeira; Davidowicz, Harry; Barletta, Fernando Branco; de Moura, Abilio Albuquerque Maranhão

2007-01-01

The purpose of this study was to compare, in vitro, by means of computerized analysis of digital radiographic images, the anatomic alterations produced in the mandibular molar tooth dentinal walls of mesiobucal canals with severe curvature by three different endodontic techniques: Progressive Preparation, Staged and Serial Preparation. A selection was made of 45 extracted, human, mandibular molars, with root curvatures greater than 25 degrees. They were divided into three groups for every technique studied, which were then sub-divided into three sub-groups in accordance with the position of the curvature along the root: cervical, median or apical. After access surgery and tooth length determination, the canals were filled with 100% Barium Sulphate radiological contrast and the teeth were then radiographed with a direct digital radiography system, using a special apparatus capable of keeping the samples in the same spatial position during the different radiographic takes. After the above-mentioned endodontic techniques had been performed, the teeth were again filled with Barium sulphate and were also radiographed under the same previously mentioned conditions. The pre- and post-operative digital images were then analyzed in two computerized programs, AutoCAD 2004 and CorelDraw 10, to assess, respectively, the areas and the horizontal alterations which occurred in the internal and external walls of the root canals. The results indicated that although no significant differences among the techniques were shown in the statistical analysis, in a descriptive analysis the Progressive Preparation technique was shown to be more regular, uniform and effective.

Effect of timing and method of post space preparation on sealing ability of remaining root filling material: in vitro microbiological study.

PubMed

Grecca, Fabiana Soares; Rosa, Angela Rezende Gomes; Gomes, Maximiliano Schünke; Parolo, Clarissa Fatturi; Bemfica, Jules Renan Dutra; Frasca, Luis Carlos da Fontoura; Maltz, Marisa

2009-10-01

To evaluate the effect of timing (immediate versus delayed) and technique of post space preparation on the ability of the residual root canal obturation to prevent coronal bacterial leakage. Sixty-six single-rooted teeth were decoronated at the cementoenamel junction. The canals were prepared according to a step-back technique and were filled with thermoplasticized gutta-percha and AH Plus endodontic sealer (Dentsply De Trey). The root segments were randomly assigned to 8 groups. The positive controls (n = 3) were instrumented but not obturated. The negative controls (n = 3) were instrumented, obturated and sealed with Cavit (3M ESPE). In the other 6 groups (n = 10 each), the post space was prepared either immediately after obturation or 7 days later using LA Axxess burs (SybronEndo) (groups 1 and 2), heated pluggers (groups 3 and 4) or solvent delivered with a hand file (groups 5 and 6). The external surface of all roots was rendered waterproof with nail varnish. Custom-made dual-chamber devices were used to evaluate leakage. The coronal third of the prepared root canal was kept in contact with artificial saliva contaminated with Enterococcus faecalis, and the root apex was submerged in tryptic soy agar medium. The root assemblies were stored at 37 degrees C and were monitored daily over a 90-day period. The occurrence of turbidity in the medium was deemed to indicate bacterial leakage, from which failure of the seal was inferred. Throughout the experimental period, there was no significant difference (p = 0.094) among the preparation techniques, either immediate or delayed, in terms of bacterial leakage. Immediate and delayed post space preparation yielded similar outcomes in terms of the canal seal. Regardless of the timing and the technique of post space preparation, coronal bacterial leakage occurred over time.

Comparative evaluation of endodontic pressure syringe, insulin syringe, jiffy tube, and local anesthetic syringe in obturation of primary teeth: An in vitro study.

PubMed

Hiremath, Mallayya C; Srivastava, Pooja

2016-01-01

The purpose of this in vitro study was to compare four methods of root canal obturation in primary teeth using conventional radiography. A total of 96 root canals of primary molars were prepared and obturated with zinc oxide eugenol. Obturation methods compared were endodontic pressure syringe, insulin syringe, jiffy tube, and local anesthetic syringe. The root canal obturations were evaluated by conventional radiography for the length of obturation and presence of voids. The obtained data were analyzed using Chi-square test. The results showed significant differences between the four groups for the length of obturation (P < 0.05). The endodontic pressure syringe showed the best results (98.5% optimal fillings) and jiffy tube showed the poor results (37.5% optimal fillings) for the length of obturation. The insulin syringe (79.2% optimal fillings) and local anesthetic syringe (66.7% optimal fillings) showed acceptable results for the length of root canal obturation. However, minor voids were present in all the four techniques used. Endodontic pressure syringe produced the best results in terms of length of obturation and controlling paste extrusion from the apical foramen. However, insulin syringe and local anesthetic syringe can be used as effective alternative methods.

Effectiveness of Sonic, Ultrasonic, and Photon-Induced Photoacoustic Streaming Activation of NaOCl on Filling Material Removal Following Retreatment in Oval Canal Anatomy.

PubMed

Jiang, Shan; Zou, Ting; Li, Dongxia; Chang, Jeffery W W; Huang, Xiaojing; Zhang, Chengfei

2016-01-01

This study aimed to assess the effectiveness of sonic, ultrasonic and laser [photon-induced photoacoustic streaming (PIPS)] irrigation activation in removing filling remnants from oval root canals after standard canal retreatment procedures with the ProTaper universal rotary retreatment system. Twenty-eight maxillary first premolars were instrumented with ProTaper NiTi rotary instruments and obturated with gutta-percha and AH Plus sealer using the continuous wave of condensation technique. After storage at 37°C and 100% humidity for 1 week, the specimens were retreated with the ProTaper universal retreatment system for the removal of filling material. Teeth were then randomly assigned into four groups (n = 7): group 1, positive control; group 2, retreated with sonic irrigation; group 3, retreated with ultrasonic irrigation; and group 4, retreated with laser irradiation. The specimens were scanned using micro-CT before instrumentation, after obturation and mechanical retreatment, and after additional activation procedures. The percentage volume of the filling remnants was measured. Specimens were split longitudinally after micro-CT scan, canal walls were examined using scanning electron microscopy (SEM), and the amount of residual filling material was scored. The filling materials' removal efficacy in the three experimental groups was higher than that of the control group (p < 0.05), whereas filling materials ranging from 1.46 ± 0.30 to 2.21 ± 0.46 mm(3) remained in the canal in all three experimental groups. Additionally, there was a significantly greater reduction in the amount of filling remnants in the PIPS group than in the sonic and ultrasonic groups (both p < 0.05), and significantly greater reduction in the ultrasonic group than the sonic group (p < 0.05). Activation of NaOCl with PIPS showed significantly better performance than sonic and ultrasonic techniques in removing the filling remnants following mechanical retreatment of oval root canals. The ultrasonic technique also performed better than the sonic technique. However, none of the additional activation procedures was able to completely eliminate the filling remnants.

Dye leakage of four root end filling materials: effects of blood contamination.

PubMed

Torabinejad, M; Higa, R K; McKendry, D J; Pitt Ford, T R

1994-04-01

The purpose of this study was to compare the amount of dye leakage (in the presence versus absence of blood) in root end cavities filled with amalgam, Super EBA, IRM, and a mineral trioxide aggregate. After removing the anatomical crowns of 90 extracted human teeth, their roots were instrumented and obturated. Except for their apical 2 mm, the root surfaces were sealed with nail polish. After removal of the apical 2 to 3 mm of each root, a standardized root end cavity was prepared. Five root ends were filled with gutta-percha and no sealer, and another five root ends were filled with sticky wax. These served as positive and negative controls, respectively. The remaining 80 roots were divided into four equal groups and filled with the test materials. For each material, half of the root end cavities were dried prior to placing the filling material. The remaining half were filled after they were contaminated with blood. All 90 roots were then immediately placed in 1% methylene blue dye for 72 h. Finally, the roots were split and linear dye penetration was measured and statistically analyzed (analysis of variance). Presence or absence of blood had no significant effect on the amount of dye leakage. However, the results showed that there was a significant leakage difference between the root end filling materials (p < 0.0001). Mineral trioxide aggregate leaked significantly less than other materials tested with or without blood contamination of the root end cavities.

Resistance to fracture of roots filled with different sealers.

PubMed

Sağsen, Burak; Ustün, Yakup; Pala, Kanşad; Demırbuğa, Sezer

2012-01-01

The aim of this study was to compare the fracture resistance of roots filled with gutta percha (GP) and different root canal sealers.Fifty-five human maxillary central incisors were selected and randomly divided into three experimental groups (Groups 1-3) and two control groups (Groups 4 and 5). They were Group 1-15 root canals filled with an epoxy resin-based sealer (AH Plus) and GP, Group 2 -15 root canals filled with a calcium silicate-based sealer (iRoot SP) and GP, Group 3: 15 root canals filled with another calcium silicate-based sealer (MTA Fillapex) and GP, Group 4: five roots were instrumented but not filled, and Group 5: five roots were neither instrumented nor filled. Compressive loading was carried out using a universal testing machine until fracture occurred. Force applied at time of fracture was recorded as fracture strength of specimen in Newtons. There were no significant differences in fracture strength among the three experimental groups (p>0.05), whose results were significantly superior to that of Group 4 (p<0.05). In conclusion, all the root canal sealers used in the present study increased the fracture resistance of instrumented root canals.

Contribution of cone beam computed tomography to the detection of apical root resorption after orthodontic treatment in root-filled and vital teeth.

PubMed

Castro, Iury; Valladares-Neto, José; Estrela, Carlos

2015-09-01

To investigate whether root-filled teeth are similar to vital pulp teeth in terms of apical root resorption (ARR) after orthodontic treatment. An original sample of cone beam computed tomography (CBCT) images of 1256 roots from 30 orthodontic patients were analyzed. The inclusion criteria demanded root-filled teeth and their contralateral vital teeth, while teeth with history of trauma had to be excluded to comply with exclusion criteria. CBCT images of root-filled teeth were compared before and after orthodontic treatment in a split-mouth design study. Tooth measurements were made with multiplanar reconstruction using axial-guided navigation. The statistical difference between the treatment effects was compared using the paired t-test. Twenty posterior root-filled teeth and their contralaterals with vital pulp were selected before orthodontic treatment from six adolescents (two boys and four girls; mean [SD] age 12.8 [1.8] years). No differences were detected between filled and vital root lengths before treatment (P  =  .4364). The mean differences in root length between preorthodontic and postorthodontic treatment in filled- and vital roots were -0.30 mm and -0.16 mm, respectively, without any statistical difference (P  =  .4197) between them. There appears to be no increase in ARR after orthodontic treatment in root-filled teeth with no earlier ARR.

Prevalence of Enterococcus faecalis in saliva and filled root canals of teeth associated with apical periodontitis

PubMed Central

Wang, Qian-Qian; Zhang, Cheng-Fei; Chu, Chun-Hung; Zhu, Xiao-Fei

2012-01-01

To investigate the prevalence of Enterococcus faecalis in saliva and filled root canals of patients requiring endodontic retreatment for apical periodontitis. Patients with apical periodontitis who were referred for endodontic retreatment were examined. The type and quality of the restoration, symptoms, quality of obturation were recorded. During retreatment, an oral rinse sample and root canal sample were cultured using brain-heart infusion agar and bile esculinazide agar to select for E. faecalis. The 16S rRNA technique was used to identify E. faecalis. A total of 32 women and 22 men (mean age: 38 years; s.d.: 11 years) and 58 teeth were studied. The prevalence of E. faecalis was 19% in the saliva and 38% in the root canals. The odds that root canals harbored E. faecalis were increased if the saliva habored this bacterium (odds ratio=9.7; 95% confidence interval=1.8–51.6; P<0.05). Teeth with unsatisfactory root obturation had more cultivable bacterial species in root canals than teeth with satisfactory root obturation (P<0.05). E. faecalis is more common in root canals of teeth with apical periodontitis than in saliva. The prevalence of E. faecalis in root canals is associated with the presence of E. faecalis in saliva. PMID:22422085

An Evaluation of GuttaFlow2 in Filling Artificial Internal Resorption Cavities: An in vitro Study.

PubMed

Mohammad, Yara; Alafif, Hisham; Hajeer, Mohammad; Yassin, Oula

2016-06-01

Obturation of root canal with internal resorption represents a major challenge in Endodontics. In spite of that, usual obturation techniques are often employed without considering the best technique to solve this problem. The goal of this study was to investigate the ability of GuttaFlow2 in filling artificial internal resorption cavities. The study sample included 36 human upper central incisors that were prepared using Protaper system (F4). Internal resorption cavities were prepared by cutting each tooth at 7 mm from the apex and preparing hemispherical cavities on both the sides and then re-attaching them. The sample was randomly separated into three groups (n = 12 in each group). In the first group, thermal injection technique (Obtura II) was employed and served as the control group. In the second group, injection of cold free-flow obturation technique with a master cone (GF2-C) was employed, whereas in the third group injection of cold free-flow obturation without a master cone (GF2) was followed. The teeth were re-cut at the same level as before and examined under a stereomicroscope. Subsequently, the captured images were transferred to AutoCAD program to measure the percentage of total filling "TF," gutta-percha "G," sealer "S," and voids "V" out of the total surface of the cross sections. All materials showed high filling properties in terms of "total filling," ranging from 99.17% (for Obtura II) to 99.72% (for GF2-C). Regarding gutta-percha percentages of filling, they ranged from 83.15 to 83.93%, whereas those for the sealer ranged from 5.71 to 15.24%. GuttaFlow2 group with a master cone appeared to give the best results despite the insignificant differences among the three groups. The GuttaFlow2 with a master cone technique seemed to be a promising filling material and gave results similar to those observed with Obtura II. It is recommended for use to obturate internal resorption cavities in clinical practice due to its good adaptability to root canal walls, ease of handling, and application. Internal resorption defects can be successfully filled with GuttaFlow2 material when supplemented with a master cone, and the results are comparable with those obtained with the Obtura II technique.

One- versus two-visit endodontic treatment of teeth with apical periodontitis: a histobacteriologic study.

PubMed

Vera, Jorge; Siqueira, José F; Ricucci, Domenico; Loghin, Simona; Fernández, Nancy; Flores, Belina; Cruz, Alvaro G

2012-08-01

This study analyzed the in vivo microbiological status of the root canal systems of mesial roots of mandibular molars with primary apical periodontitis after 1- or 2-visit endodontic treatment. Mesial root canals were instrumented by using either a combination of K3 and LightSpeed instruments (mesiobuccal canals) or the ProTaper system (mesiolingual canals), with 5% NaOCl irrigation. Patency files were used. Smear layer was removed, and a final rinse with 5 mL of 2% chlorhexidine was performed. In the 2-visit group (7 roots, 14 canals), canals were medicated with calcium hydroxide for 1 week and then obturated by using the continuous wave of compaction technique. In the 1-visit group (6 roots, 12 canals), canals were immediately obturated after chemomechanical procedures. Teeth were extracted 1 week after root canal instrumentation and processed for histobacteriologic analysis. In the 1-visit group, no case was completely free of bacteria; residual bacteria occurred in the main root canal (5 of 6 cases), isthmus (5 of 6), apical ramifications (4 of 6), and dentinal tubules (5 of 6). In the 2-visit group, 2 cases were rendered bacteria-free; residual bacteria were found in the main canal only in 2 cases (none of them with persistent dentinal tubule infection), in the isthmus (4 of 7 cases), and in ramifications (2 of 7). The 2 instrumentation techniques performed similarly. When filling material was observed in ramifications, it was usually intermixed with necrotic tissue, debris, and bacteria. The 2-visit protocol by using an interappointment medication with calcium hydroxide resulted in improved microbiological status of the root canal system when compared with the 1-visit protocol. Residual bacteria were more frequent and abundant in ramifications, isthmuses, and dentinal tubules when root canals were treated without an interappointment medication. Apical ramifications and isthmuses were never completely filled. The use of an antibacterial interappointment agent is necessary to maximize bacterial reduction before filling. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Comprehensive Analysis of Secondary Dental Root Canal Infections: A Combination of Culture and Culture-Independent Approaches Reveals New Insights

PubMed Central

Anderson, Annette Carola; Hellwig, Elmar; Vespermann, Robin; Wittmer, Annette; Schmid, Michael; Karygianni, Lamprini; Al-Ahmad, Ali

2012-01-01

Persistence of microorganisms or reinfections are the main reasons for failure of root canal therapy. Very few studies to date have included culture-independent methods to assess the microbiota, including non-cultivable microorganisms. The aim of this study was to combine culture methods with culture-independent cloning methods to analyze the microbial flora of root-filled teeth with periradicular lesions. Twenty-one samples from previously root-filled teeth were collected from patients with periradicular lesions. Microorganisms were cultivated, isolated and biochemically identified. In addition, ribosomal DNA of bacteria, fungi and archaea derived from the same samples was amplified and the PCR products were used to construct clone libraries. DNA of selected clones was sequenced and microbial species were identified, comparing the sequences with public databases. Microorganisms were found in 12 samples with culture-dependent and -independent methods combined. The number of bacterial species ranged from 1 to 12 in one sample. The majority of the 26 taxa belonged to the phylum Firmicutes (14 taxa), followed by Actinobacteria, Proteobacteria and Bacteroidetes. One sample was positive for fungi, and archaea could not be detected. The results obtained with both methods differed. The cloning technique detected several as-yet-uncultivated taxa. Using a combination of both methods 13 taxa were detected that had not been found in root-filled teeth so far. Enterococcus faecalis was only detected in two samples using culture methods. Combining the culture-dependent and –independent approaches revealed new candidate endodontic pathogens and a high diversity of the microbial flora in root-filled teeth with periradicular lesions. Both methods yielded differing results, emphasizing the benefit of combined methods for the detection of the actual microbial diversity in apical periodontitis. PMID:23152922

Biocompatibility of root-end filling materials: recent update

PubMed Central

Gupta, Saurabh Kumar; Newaskar, Vilas

2013-01-01

The purpose of a root-end filling is to establish a seal between the root canal space and the periradicular tissues. As root-end filling materials come into contact with periradicular tissues, knowledge of the tissue response is crucial. Almost every available dental restorative material has been suggested as the root-end material of choice at a certain point in the past. This literature review on root-end filling materials will evaluate and comparatively analyse the biocompatibility and tissue response to these products, with primary focus on newly introduced materials. PMID:24010077

An in vitro evaluation of the apical sealing ability of new polymeric endodontic filling systems.

PubMed

Onay, Emel Olga; Ungor, Mete; Unver, Saadet; Ari, Hale; Belli, Sema

2009-08-01

The objective of this study was to compare the short-term sealing abilities of recently introduced polymeric endodontic filling systems. Root canals of 120 extracted and decoronated human single-rooted teeth were instrumented using crown-down technique with HERO Shaper rotary instruments. The roots were divided randomly into 8 groups (6 experimental and 2 control groups of 15 roots each) and filled with different combinations of core and sealer as follows: group 1, RealSeal/Resilon; group 2, RealSeal/Herofill; group 3, Hybrid Root Seal/Resilon; group 4, Hybrid Root Seal/Herofill; group 5, MM-Seal/Resilon; group 6, MM-Seal/Herofill; group 7, positive controls (Herofill only); group 8, negative controls. Apical leakage quantity was evaluated after 1 week by using a fluid filtration model. For each sample, measurements of fluid movement were recorded at 2-minute intervals for a total of 8 minutes, and then averaged. The data were calculated and analyzed using the Kolmogorov-Smirnov test, 1-way analysis of variance (ANOVA), and the Tukey test. Significance was set at P less than .05. Multiple paired comparisons (Tukey test) showed that, of all the groups, MM-Seal/Herofill combination exhibited the least microleakage, and RealSeal/Herofill combination ranked second in this regard. The mean leakage values for the RealSeal/Resilon and MM-Seal/Resilon combinations were both significantly higher than the means for the other 4 experimental groups (P < .01). Hybrid Root Seal combined with Resilon resulted in significantly less microleakage than Hybrid Root Seal combined with Herofill (P = .001). The results suggest that the sealing properties of epoxy-resin-based sealer (MM-Seal) combined with gutta-percha (Herofill) are superior to those of methacrylate-based sealers (Hybrid Root Seal and Realseal) combined with Resilon.

Comparing the Marginal Adaptation of Cold Ceramic and Mineral Trioxide Aggregate by Means of Scanning Electron Microscope: An In vitro Study.

PubMed

Mokhtari, Fatemeh; Modaresi, Jalil; Javadi, Gholamreza; Davoudi, Amin; Badrian, Hamid

2015-09-01

Long-term success of endodontic surgeries is often influenced by the type of root-end filling material (RFM). The aim of present study was to compare the marginal adaptation of two different RFM, cold ceramic (CC) and mineral trioxide aggregate (MTA), using scanning electron microscope (SEM). About 20 extracted human single-rooted teeth were collected and stored into sodium hypochlorite 5.25%. The teeth were decronated from the cemento-enamel junction to prepare 16 mm roots. The working length was measured, and 1/3 coronal of the canal was prepared by Gates-Glidden drills. Apical flaring was followed by K file size # 40-70 based on step back technique. After filling of the canals, 3 mm above the apex was cut at 90° to the long axis. Furthermore, 3 mm of the filling was removed from the apical part using the ultrasonic device. All of the prepared specimens were divided into two groups and were retro filled by MTA and CC. The roots were cut horizontally from 1 mm above the apical part, and dentin-filling material interface was observed by SEM. Finally, the collected data were analyzed by Mann-Whitney test and using SPSS software version 18 at a significant level of 0.05. The mean interfacial adaptation was higher in CC group. However, no significant differences were observed by statistical test (P = 0.35). Both CC and MTA had similar marginal adaptation as RFM however in vivo studies are recommended for better determination.

In vitro comparison of gutta-percha-filled area percentages in root canals instrumented and obturated with different techniques.

PubMed

Yilmaz, Ayca; Karagoz-Kucukay, Isil

2017-01-01

To evaluate the efficacy of different obturation techniques in root canals instrumented either by hand or rotary instruments with regard to the percentage of gutta- percha-filled area (PGFA). One hundred and sixty extracted mandibular premolars with single, straight root canals were studied. Root canals were prepared to an apical size of 30 by hand with a modified crown-down technique or the ProTaper and HEROShaper systems. Teeth were divided into eight groups (n=20) according to the following instrumentation and obturation techniques: G1: Hand files+lateral condensation (LC), G2: Hand files+Thermafil, G3: ProTaper+LC, G4: ProTaper+single-cone, G5: ProTaper+ProTaper-Obturator, G6: HEROShaper+LC, G7: HEROShaper+single-cone, G8: HEROShaper+HEROfill. Horizontal sections were cut at 1, 3, 5, 7, 9, 11 and 13 mm from the apical foramen. A total of 1120 sections obtained were digitally photographed under a stereomicroscope set at 48X magnification. The cross-sectional area of the canal and the gutta-percha was measured by digital image analysis and the PGFA was calculated for each section. The mean of the PGFA in Thermafil (G2), ProTaper-Obturator (G5) and HEROfill (G8) groups was significantly higher than the other groups. In G3 and G4, PGFA showed no significant difference in the apical segments whereas PGFA was significantly higher at the middle and coronal segments in G3. In G6 and G7, PGFA showed no significant difference in the apical and middle segments whereas PGFA was significantly higher at the coronal segments in G6. The carrier-based gutta-percha obturation systems revealed significantly higher PGFA in comparison to single-cone and lateral condensation techniques.

Impact of cross-sectional root canal shape on filled canal volume and remaining root filling material after retreatment.

PubMed

Rechenberg, D K; Paqué, F

2013-06-01

To assess the impact of cross-sectional root canal shape (CSRCS) on the canal volume that can be filled and the root filling material that remains following a subsequent retreatment procedure. A total of 15 extracted two-rooted human maxillary premolars and 15 mandibular first molars were used. Both root canals in the premolars (N = 30) and the distal root canal in the molars (N = 15) were prepared using ProFile instruments and filled by lateral compaction using gutta-percha and AH Plus sealer. Canals were later retreated using the last ProFile used for instrumentation followed by two ProFiles of increasing size. Teeth were viewed in a μCT scanner before and after each treatment step. Defined and validated threshold levels were used to differentiate empty root canal volumes, root dentine and root filling materials from each other. CSRCS was defined as the averaged ratio between bucco-lingual and mesio-distal canal diameter (round ≤ 1, oval 1-2, long oval 2-4 and flattened ≥ 4), determined for each 1 mm over the total root length. Data were averaged between the two canals in premolars, only the distal canals were assessed in molars. Parametric and non-parametric tests were used to statistically compare the data, alpha = 0.01. Canals in premolars had a round CSRCS after preparation (1.0 ± 0.0), whereas distal counterparts in molars were oval (1.6 ± 0.5). Significantly (P < 0.01) more canal volume could be filled, and significantly less filling material remained after retreatment in premolars compared with mandibular molar distal canals. There was a high correlation between CSRCS, filled canal volume and remaining filling material. The endodontic procedures under investigation were significantly influenced by the cross-sectional root canal shape. © 2012 International Endodontic Journal. Published by Blackwell Publishing Ltd.

Comparison of Gap Volume after Retrofilling Using 4 Different Filling Materials: Evaluation by Micro-computed Tomography.

PubMed

Kim, Sue Youn; Kim, Hyeon-Cheol; Shin, Su-Jung; Kim, Euiseong

2018-04-01

The purpose of this study was to evaluate the gap volume between dentin and root-end filling materials. Four root-end filling materials were compared in the present study: ProRoot MTA (PRM; Dentsply Tulsa Dental, Tulsa, OK), MTA Angelus (MAG; Angelus, Londrina, Brazil), EndoCem MTA (ECM; Maruchi, Wonju, Korea), and RetroMTA (RTM; BioMTA, Seoul, Korea). Forty-eight single-rooted, extracted human teeth were instrumented with nickel-titanium instruments and oburated with gutta-percha. The apical 3 mm of the root tip was resected, and root-end preparation was performed with a diamond bur. The root-end cavity was filled with the experimental filling materials for the 4 designated groups (n = 10). Then, the samples were scanned with micro-computed tomographic (micro-CT) imaging. Three-dimensional images of the samples were reconstructed, and the volume of the gap between the tooth surface (dentinal wall) and the root-end filling materials was measured. The percentage volume of the gap between the tooth structure and the root-end filling material (V G %) was calculated. Data were analyzed using the Kruskal-Wallis and Mann-Whitney U tests at a significance level of 95%. The median V G % values for the PRM, MAG, ECM, and RTM groups were 0.00472, 0.00134, 0.00014, and 0.00071, respectively. The ProRoot MTA group showed the greatest gap volume percentage among the experimental groups with a significant statistical difference (P < .05). From the micro-CT analysis, ProRoot MTA had a greater gap volume percentage than other root-end filling materials. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Further Treatments of Root-filled Teeth in the Swedish Adult Population: A Comparison of Teeth Restored with Direct and Indirect Coronal Restorations.

PubMed

Dawson, Victoria S; Isberg, Per-Erik; Kvist, Thomas; Fransson, Helena

2017-09-01

The aim of this study was to evaluate the frequencies of nonsurgical retreatment, root-end surgery, extraction, and further restoration of root-filled teeth in Sweden in 2009 during a follow-up period of 5 years and to compare the outcomes in teeth restored with direct or indirect restorations. Data from the Swedish Social Insurance Agency were analyzed, and the frequencies of nonsurgical retreatment, root-end surgery, extractions, and further restoration were calculated for all teeth registered as root filled during 2009. Chi-square tests were applied to detect any significant differences in the frequency of further treatment in teeth registered as restored with either a direct or an indirect restoration within 6 months of root filling. Of the 248,299 teeth reported root filled in Sweden in 2009, nonsurgical retreatment was registered in 2.2%, root-end surgery in 1.0%, and extractions in 9.2% during the follow-up period. Of the teeth restored with a direct restoration within 6 months after the root filling, 30.3% were registered as having undergone at least 1 further direct restoration; the corresponding percentage of teeth with indirect restorations was 6.4%. A statistically significant difference in the frequency of nonsurgical retreatment, extraction, and further restoration was found; teeth restored with an indirect restoration within 6 months of root filling had fewer of these treatments than those restored by direct restoration. Low frequencies of nonsurgical retreatment and root-end surgery were reported 5 years after root filling, whereas extraction was more common. Fewer additional treatment procedures were registered for teeth with indirect restorations than for those with direct restorations. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

External root resorption during orthodontic treatment in root-filled teeth and contralateral teeth with vital pulp: A clinical study of contributing factors.

PubMed

Lee, Yun Ju; Lee, Tae Yeon

2016-01-01

There is a lack of research to support the belief that root canal treatment can be considered for stopping or decreasing external apical root resorption (EARR). There is conflicting evidence as to whether root-filled teeth are more or less likely to experience EARR after orthodontic treatment. The purpose of this study was to compare the degree of EARR of root-filled teeth with that of contralateral teeth with vital pulp after fixed orthodontic treatment. The study sample consisted of 35 patients aged 25.23 ± 4.92 years who had at least 1 root-filled tooth before orthodontic treatment. Digital panoramic radiographs of each patient taken before and after orthodontic treatment were used to measure the EARR. The Student t test for matched pairs and the Pearson correlation analysis were applied. The mean EARR values were 0.22 (0.14, 0.35) for root-filled teeth and 0.87 (0.59, 1.31) for contralateral teeth with vital pulp, indicating significantly less EARR for root-filled teeth compared with the contralateral teeth with vital pulp after orthodontic treatment. EARR was influenced by the patient's age, treatment duration, treatment type, and periapical pathosis, but not by tooth type and sex. Root-filled teeth appear to be associated with significantly less EARR than are contralateral teeth with vital pulp. This study suggests that the possible complication of EARR in root-filled teeth may not be an important consideration in orthodontic treatment planning, and root canal treatment can be considered for stopping or decreasing EARR when severe EARR occurs during orthodontic treatment. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

A comparative In vivo efficacy of three spiral techniques versus incremental technique in obturating primary teeth.

PubMed

Chandrasekhar, Shalini; Prasad, Madu Ghanashyam; Radhakrishna, Ambati Naga; Saujanya, Kaniti; Raviteja, N V K; Deepthi, B; Ramakrishna, J

2018-01-01

The aim of this study was to evaluate the efficiency of four different obturating techniques in filling the radicular space in primary teeth. This clinical trial was carried out on 34 healthy, cooperative children (5-9 years) who had 63 carious primary teeth indicated for pulpectomy. They were divided into four groups, such that in each group, a total of 40 canals were allotted for obturation with respective technique. The root canals of selected primary teeth were filled with Endoflas obturating material using either bi-directional spiral (Group 1); incremental technique (Group 2), past inject (Group 3) or lentulo spiral (Group 4) according to the groups assigned. The effectiveness of the obturation techniques was assessed using postoperative radiographs. The assessment was made for a depth of fill in the canal, the presence of any voids using Modified Coll and Sadrian criteria. The obtained data were analyzed by using ANOVA test and unpaired t-test. Bi-directional spiral and lentulo spiral were superior to other techniques in providing optimally filled canals (P< 0.05). The bi-directional spiral was superior to lentulo spiral in preventing overfill (P< 0.05). Based on the present study results, bi-directional spiral can be recommended as an alternate obturating technique in primary teeth.

Comparison between the use of an ultrasonic tip and a microhead handpiece in periradicular surgery: a prospective randomised trial.

PubMed

Shearer, Jane; McManners, Joseph

2009-07-01

Innovations in periradicular surgery for failed treatment of orthograde root canal disease have been well-documented. We know of no prospective studies that have compared success rates of conventional methods with these presumed advances. In this prospective randomised trial we compare the use of an ultrasonic retrotip with a microhead bur in the preparation of a retrograde cavity. Outcome was estimated clinically by estimation of pain, swelling, and sinus, and radiographically by looking at infill of bone and retrograde root filling 2 weeks and 6 months postoperatively. Both methods used other surgical techniques including microinstruments to place the retrograde root filling. The success rate of the ultrasonic method was higher (all patients, n=26) than that of the microhead method (n=19 of 21). A larger study with longer follow up is required to consolidate this evidence.

Accuracy of two root canal length measurement devices integrated into rotary endodontic motors when removing gutta-percha from root-filled teeth.

PubMed

Uzun, O; Topuz, O; Tinaz, C; Nekoofar, M H; Dummer, P M H

2008-09-01

To evaluate ex vivo the accuracy of the integrated electronic root canal length measurement devices within TCM Endo V and Tri Auto ZX motors whilst removing gutta-percha and sealer from filled root canals. Forty freshly extracted maxillary and mandibular incisor teeth with mature apices were selected. Following access cavity preparation, the length of the root canals were measured visually 0.5 mm short of the major foramen (TL). The canals were prepared using the HERO 642 system and then filled with gutta-percha and AH26 sealer using a lateral compaction technique. After 7 days the coronal temporary filling was removed and the roots mounted in an alginate experimental model. The roots were then randomly divided in two groups. The access cavities were filled with chloroform to soften the gutta-percha and allow its penetration using the Tri Auto ZX and the TCM Endo V devices in groups 1 and 2, respectively. The 'automatic apical reverse function' (ARL) of both devices was set to start at the 0.5 setting and the rotary instrument inserted inside the root canal until a beeping sound was heard and the rotation of the file stopped automatically. Once the auto reverse function had been initiated, the foot pedal of the motor was inactivated and the rubber stop placed against the reference point. The distance between the file tip and rubber stop was measured using a digital calliper to 0.01 mm accuracy (ARL). Then, a size 20, 0.02 taper instrument was attached to each device and inserted into the root canals without rotary motion until the integrated ERCLMDs positioned the instrument tips at the 0.5 setting as suggested by the devices. This length was again measured using a digital calliper (EL). The Mann-Whitney U-test was used to investigate statistical differences between the true canal length and those indicated by the two devices when used in 'automatic ARL and when inserted passively (EL). In the presence of gutta-percha, sealer and chloroform, the auto-reverse function for the Tri Auto ZX and TCM Endo V, set to start at 0.5 level, was initiated beyond the foramen in 60% and 95% of the samples, respectively during active (rotary) penetration of the instruments. There was a statistically significant difference between the devices for the mean discrepancies between the length at which the auto reverse function was initiated and the true length (P < 0.001). Electronic detection of the apical terminus when the instruments were introduced passively (not rotating) was beyond the foramen in 20% and 37% of cases in the Tri Auto ZX group and the TCM Endo V group, respectively. There was a statistically significant difference between the devices for the mean discrepancies between the electronically determined (passive) length and true length (P < 0.01). The auto reverse function of the Tri Auto ZX and TCM Endo V devices, set to start at 0.5 level, were initiated beyond the foramen in the majority of root-filled teeth during active (rotating) penetration of root filling material. Thus, this automatic function must be used with caution when removing gutta-percha root fillings. There were significant differences between the accuracy of measurements in active (rotating) and passive (not-rotating) modes; both devices were more accurate when used in passive mode. However, the Tri Auto ZX was significantly more accurate in a greater proportion of cases.

Periapical status and quality of root fillings in a selected adult Riga population.

PubMed

Jersa, Ilana; Kundzina, Rita

2013-01-01

The aim of the study was to assess the prevalence of apical periodontitis and quality of root canal fillings in an adult Riga subpopulation. Panoramic radiographs of Latvian adults 35-44 year old attending a private dental clinic for the first time during the period of 2004-2008 were included in the study. Totally, 312 out of 1248 panoramic radiographs were randomly selected and examined for periapical conditions and endodontic treatment quality. The technical quality of root fillings was evaluated in terms of length in relation to the root apex and lateral adaptation to the canal wall. The periapical status was assessed using the PAI index. The data were analyzed using SPSS 14 computer software program. Statistical significance was assessed by the chi-squared (Pearson's) test. Out of the 312 individuals examined 224 (72%) had one or more teeth with apical periodontitis (PAI 3-5) and 272 individuals (87%) had one or more endodontically treated teeth. Amongst 7065 teeth evaluated 1255 (18%) were endodontically treated. Only 285 teeth (23%) of the root canal treated teeth were with complete root canal fillings. There was a statistically significant relationship between quality of root canal fillings and apical periodontitis (p<0.0001). In teeth with complete fillings only 15% were with apical periodontitis, but apical periodontitis were detected in 342 teeth (35%) with incomplete root fillings. The results from this study indicates a high prevalence of apical periodontitis and low quality of root fillings in a selected adult Riga population.

Measurement of the percentage of root filling in oval-shaped canals obturated with Thermafil Obturators and Beefill 2in1: In vitro study

PubMed Central

Collado-Castellanos, Nicolás; Alegre-Domingo, Teresa; Dolz-Solsona, María; Faus-Matoses, Vicente

2015-01-01

Background The aim of the study was to measure the percentage of root canal fillings in long oval canals obturated with thermoplasticized gutta-percha techniques, Beefill 2in1® and Thermafil Obturators®. Material and Methods Fifty four mandibular incisors were selected after bucco-lingual and mesio-distal radiographs showed at 5 mm from apex an internal long:short diameter ≥2. Teeth were instrumented with Protaper Universal and divided in two groups of 27. Group 1 was obturated with Thermafil Obturators® and group 2 with Beefill 2in1®. Two horizontal sections were cut at 5 and 7 mm from the apex and photographed in a stereo-microscope. The total area of the canal and filled canal in cross-sections were measured with AutoCad and the percentages of gutta-percha-sealer and voids in the canal were obtained. Results Both systems achieved high percentage of filled canal, Thermafil 96.8% and Beefill 2in1 98.9%. The percentages of voids in both groups were very low. No significant differences were found between the two groups . The percentage obtained at 5 and 7 mm from the apex in both groups showed no significant difference. Conclusions The percentages of filled canal (gutta-percha-sealer) were high and these two thermoplasticized techniques are suitable for long oval canals obturation. Key words:Long oval canal, oval canal, thermoplasticized obturation. PMID:26155350

Measurement of the percentage of root filling in oval-shaped canals obturated with Thermafil Obturators and Beefill 2in1: In vitro study.

PubMed

Faus-Llácer, Vicente; Collado-Castellanos, Nicolás; Alegre-Domingo, Teresa; Dolz-Solsona, María; Faus-Matoses, Vicente

2015-04-01

The aim of the study was to measure the percentage of root canal fillings in long oval canals obturated with thermoplasticized gutta-percha techniques, Beefill 2in1® and Thermafil Obturators®. Fifty four mandibular incisors were selected after bucco-lingual and mesio-distal radiographs showed at 5 mm from apex an internal long:short diameter ≥2. Teeth were instrumented with Protaper Universal and divided in two groups of 27. Group 1 was obturated with Thermafil Obturators® and group 2 with Beefill 2in1®. Two horizontal sections were cut at 5 and 7 mm from the apex and photographed in a stereo-microscope. The total area of the canal and filled canal in cross-sections were measured with AutoCad and the percentages of gutta-percha-sealer and voids in the canal were obtained. Both systems achieved high percentage of filled canal, Thermafil 96.8% and Beefill 2in1 98.9%. The percentages of voids in both groups were very low. No significant differences were found between the two groups . The percentage obtained at 5 and 7 mm from the apex in both groups showed no significant difference. The percentages of filled canal (gutta-percha-sealer) were high and these two thermoplasticized techniques are suitable for long oval canals obturation. Key words:Long oval canal, oval canal, thermoplasticized obturation.

Sealing ability of grar MTA AngelusTM, CPM TM and MBPc used as apical plugs.

PubMed

Orosco, Fernando Accorsi; Bramante, Clovis Monteiro; Garcia, Roberto Brandão; Bernadineli, Norberti; Moraes, Ivaldo Gomes de

2008-01-01

This study evaluated the sealing ability of apical plugs fabricated with gray MTA Angelus sealer, CPM TM sealer and MBPc sealer. The root canals of 98 extracted single-rooted human teeth were instrumented with #5 to #1 Gates Glidden drills according to the crown-down technique until the #1 drill could pass through the apical foramen. The specimens were then prepared with K-files, starting with an ISO 50 until an ISO 90 could be visualized 1 mm beyond the apex. After root canal preparation, the external surface of each root was rendered impermeable and roots were assigned to 3 experimental groups (n = 30), which received a 5-mm thick apical plug of gray MTA Angelus, CPM and MBPc, and two control groups (n=4). The remaining portion of the canal in the experimental groups was filled by the lateral condensation technique. The teeth of each group, properly identified, were fixed on utility wax by their crowns and were placed in plastic flasks, leaving the apex free and facing upward. The flasks were filled with 0.2% Rhodamine B solution, pH 7.0, so as to completely cover the root apex of all teeth. The sealing ability was analyzed by measuring 0.2% Rhodamine B leakage after all groups had been maintained in this solution for 48 hours. Data were analyzed statistically by Kruskal-Wallis test and Dunn test with a=5%. The results showed that, among the tested materials used for fabrication of apical plugs, MBPc sealer had the least amount of leakage with statistically significant difference (p<0.05).

SEALING ABILITY OF GRAY MTA ANGELUS™, CPM™ AND MBPC USED AS APICAL PLUGS

PubMed Central

Orosco, Fernando Accorsi; Bramante, Clovis Monteiro; Garcia, Roberto Brandão; Bernardineli, Norberti; de Moraes, Ivaldo Gomes

2008-01-01

This study evaluated the sealing ability of apical plugs fabricated with gray MTA Angelus™ sealer, CPM™ sealer and MBPc sealer. The root canals of 98 extracted single-rooted human teeth were instrumented with #5 to #1 Gates Glidden drills according to the crown-down technique until the #1 drill could pass through the apical foramen. The specimens were then prepared with K-files, starting with an ISO 50 until an ISO 90 could be visualized 1 mm beyond the apex. After root canal preparation, the external surface of each root was rendered impermeable and roots were assigned to 3 experimental groups (n = 30), which received a 5-mm thick apical plug of gray MTA Angelus™, CPM ™ and MBPc, and two control groups (n=4). The remaining portion of the canal in the experimental groups was filled by the lateral condensation technique. The teeth of each group, properly identified, were fixed on utility wax by their crowns and were placed in plastic flasks, leaving the apex free and facing upward. The flasks were filled with 0.2% Rhodamine B solution, pH 7.0, so as to completely cover the root apex of all teeth. The sealing ability was analyzed by measuring 0.2% Rhodamine B leakage after all groups had been maintained in this solution for 48 hours. Data were analyzed statistically by Kruskal-Wallis test and Dunn test with a=5%. The results showed that, among the tested materials used for fabrication of apical plugs, MBPc sealer had the least amount of leakage with statistically significant difference (p<0.05). PMID:19089289

Periapical inflammation subsequent to coronal inoculation of dog teeth root filled with resilon/epiphany in 1 or 2 treatment sessions with chlorhexidine medication.

PubMed

Santos, João M; Palma, Paulo J; Ramos, João C; Cabrita, António S; Friedman, Shimon

2014-06-01

Therapeutic methods that inhibit microbial ingress into filled root canals are desirable. This in vivo study assessed the inhibition of periapical inflammation subsequent to coronal inoculation in canals medicated with 2% chlorhexidine gel and filled with Resilon/Epiphany (Pentron Clinical Technologies, Wallingford, CT). Six Beagle dogs each had 10 two-rooted premolars treated. In group 1 (n = 36 roots), 1 root/tooth had the canal conditioned with Primer Epiphany, filled with Epiphany sealer and Resilon core in 1 session, and coronally sealed with PhotacFil. In group 2 (n = 36 roots), the second root/tooth had the canal medicated with 2% chlorhexidine gel for 1 week and then filled and coronally sealed as in group 1. After 3 weeks, canals were exposed to the oral environment for 7 days, inoculated with isologous plaque, and coronally sealed. Negative controls treated as groups 1 and 2 remained sealed. Positive controls had canals unfilled and exposed. Seven months after inoculation, dogs were euthanized; jaw blocks processed for histologic examination; and periapical inflammation (PI) recorded as none, mild, or severe. In groups 1 and 2, severe PI occurred in 5 of 65 roots (8%) and mild PI in 18 of 65 roots (28%) with a significantly higher (P = .031) PI incidence in group 2 than in group 1. Negative controls had only mild PI in 9 of 29 roots (31%). Roots medicated with 2% chlorhexidine gel had mild PI significantly more (P = .009) than roots filled in 1 session (more than 2-fold). Intracanal medication with 2% chlorhexidine gel and root filling with Resilon/Epiphany did not effectively inhibit apical periodontitis subsequent to coronal inoculation. Copyright © 2014 American Association of Endodontists. All rights reserved.

Comparison of the efficacy of nickel-titanium rotary systems with or without the retreatment instruments in the removal of gutta-percha in the apical third

PubMed Central

2014-01-01

Background The purpose of this study was to compare the efficacy of nickel-titanium rotary systems with or without the retreatment instruments in the removal of gutta-percha from the apical third. Methods The systems compared were as follows: ProTaper Universal (PT), ProTaper Universal Retreatment (PTr), Mtwo (M2) and Mtwo Retreatment (M2r). Sixty extracted mandibular incisors were treated with a crown-down technique and filled with gutta-percha and sealer. The apical diameter was standardized in 0.30 mm, 1 mm from the apex. The teeth were distributed into 4 experimental groups: PT, PTr, M2 and M2r. In PTr and M2r groups, filling materials were removed by PTr/M2r followed by root canals preparation up to a PT F4/M2 40; in groups PT/M2, the filling materials were removed and the root canals were prepared by PT up to a PT F4/M2 up to a M2 40. The roots were split and photomicrographing. The percentage of clean area in the apical 5 mm was calculated using software. Data were analyzed with the Kruskal-Wallis test. Results Remaining material was found in all hemisections and there was no statistically significant difference between the groups (p = 0.09). Considering the surface of the canal walls of all teeth, the mean of the percentage of clean area was 54%. Conclusions Considering the applied methodology, remaining filling material was found in all hemisections, regardless of the retreatment technique and PT or M2 were as effective as PTr/PT or M2r/M2. PMID:25128277

Effect of photodynamic therapy and non-thermal plasma on root canal filling: analysis of adhesion and sealer penetration.

PubMed

Menezes, Marilia; Prado, Maíra; Gomes, Brenda; Gusman, Heloisa; Simão, Renata

2017-01-01

The aim of this study was to evaluate the effect of photodynamic therapy (PDT) and non-thermal plasma (NTP) on adhesion and sealer penetration in root canals. Sixty single-rooted premolars were used. The teeth were prepared using a crown-down technique. NaOCl and EDTA were used for irrigation and smear layer removal, respectively. The root canals were divided into three groups: control, PDT, and NTP. After treatments, the roots were filled using gutta-percha and either AH Plus (AHP) or MTA Fillapex (MTAF) sealers. Samples were sectioned at 4, 8, and 12 mm from the apex (1-mm slices)and analyzed by the push-out bond strength test (adhesion) and confocal laser scanning microscopy (sealer penetration). Data were statistically evaluated using Kruskal-Wallis, Dunn's, and Spearman's tests. Regarding AHP, bond strength was similar in the NTP group and in the control group, but significantly lower in the PDT group. As to MTAF, both therapies showed lower values than the control group. In the confocal analysis of AHP, maximum and mean penetration, and penetrated area were statistically higher in the control group than in the PDT and NTP groups. Penetrated perimeter was similar among groups. Regarding MTAF, all parameters yielded better results in the NTP than in the control group. The PDT and control groups showed similar results except for penetrated area. PDT and plasma therapy affected the adhesion and sealer penetration of root canals filled with AH Plus and MTA Fillapex and there is no positive correlation between adhesion and sealer penetration.

Study of external root resorption during orthodontic treatment in root filled teeth compared with their contralateral teeth with vital pulps.

PubMed

Llamas-Carreras, J M; Amarilla, A; Solano, E; Velasco-Ortega, E; Rodríguez-Varo, L; Segura-Egea, J J

2010-08-01

To determine whether root filled teeth and those with vital pulps exhibit a similar degree of external root resorption (ERR) as a consequence of orthodontic treatment. The study sample consisted of 77 patients, with a mean age of 32.7 +/- 10.7 years, who had one root filled tooth before completion of multiband/bracket orthodontic therapy for at least 1 year. For each patient, digital panoramic radiographs taken before and after orthodontic treatment were used to determine the proportion of external root resorption (PRR), defined as the ratio between the root resorption in the root filled tooth and that in its contralateral tooth with a vital pulp. The student's t-test, anova and logistic regression analysis were used to determine statistical significance. The mean PRR was 1.00 +/- 0.13, indicating that, in the total sample, there were no significant differences in root resorption in the root filled teeth and their contralateral teeth with vital pulps. Multivariate logistic regression analysis suggested that PRR was significantly greater in incisors (P = 0.0014; odds ratio = 6.2885, C.I. 95% = 2.0-19.4), compared to other teeth, and in women (P = 0.0255; odds ratio = 4.2, C.I. 95% = 1.2-14.6), compared to men. There was no significant difference in the amount or severity of external root resorption during orthodontic movement between root filled teeth and their contralateral teeth with vital pulps.

Evaluation of debris extruded apically during the removal of root canal filling material using ProTaper, D-RaCe, and R-Endo rotary nickel-titanium retreatment instruments and hand files.

PubMed

Topçuoğlu, Hüseyin Sinan; Aktı, Ahmet; Tuncay, Öznur; Dinçer, Asiye Nur; Düzgün, Salih; Topçuoğlu, Gamze

2014-12-01

The aim of this study was to evaluate the amount of debris extruded apically during the removal of root canal filling material using ProTaper (Dentsply Maillefer, Ballaigues, Switzerland), D-RaCe (FKG Dentaire, La Chaux-de-Fonds, Switzerland), and R-Endo (Micro-Mega, Besançon, France) nickel-titanium (NiTi) rotary retreatment instruments and hand files. Sixty extracted single-rooted mandibular premolar teeth were prepared with K-files and filled with gutta-percha and AH Plus sealer (Dentsply DeTrey, Konstanz, Germany). The teeth were then randomly assigned to 4 groups (n = 15 for each group) for retreatment. The removal of canal filling material was performed as follows: hand files, ProTaper, D-RaCe, and R-Endo retreatment instruments. Debris extruded apically during the removal of canal filling material was collected into preweighed Eppendorf tubes. The tubes were then stored in an incubator at 70°C for 5 days. The weight of the dry extruded debris was established by subtracting the preretreatment and postretreatment weight of the Eppendorf tubes for each group. The data obtained were analyzed using 1-way analysis of variance and Tukey post hoc tests. All retreatment techniques caused the apical extrusion of debris. Hand files produced significantly more debris when compared with ProTaper, D-RaCe, and R-Endo rotary systems (P < .05). There was no statistical difference between the ProTaper, D-RaCe, and R-Endo retreatment systems (P > .05). The findings showed that during the removal of root canal filling material, rotary NiTi retreatment instruments used in this study caused less apical extrusion of debris compared with hand files. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

21 CFR 872.3820 - Root canal filling resin.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Root canal filling resin. 872.3820 Section 872.3820 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification...

Technological advances in endodontics: treatment of a mandibular molar with internal root resorption using a reciprocating single-file system.

PubMed

de Souza, Samir Noronha; Marques, André Augusto Franco; Sponchiado-Júnior, EmÍlio Carlos; Roberti Garcia, Lucas da Fonseca; da Frota, Matheus Franco; de Carvalho, Fredson Márcio Acris

2017-01-01

The field of endodontics has become increasingly successful due to technological advances that allow clinicians to solve clinical cases that would have been problematic a few years ago. Despite such advances, endodontic treatment of teeth with internal root resorption remains challenging. This article presents a clinical case in which a reciprocating single-file system was used for endodontic treatment of a mandibular molar with internal root resorption. Radiographic examination revealed the presence of internal root resorption in the distobuccal root canal of the mandibular right first molar. A reciprocating single-file system was used for root canal instrumentation and final preparation, and filling was obtained through a thermal compaction technique. No painful symptoms or periapical lesions were observed in 12 months of follow-up. The results indicate that a reciprocating single-file system is an adequate alternative for root canal instrumentation, particularly in teeth with internal root resorption.

In vitro evaluation of efficacy of different rotary instrument systems for gutta percha removal during root canal retreatment

PubMed Central

Joseph, Mercy; Malhotra, Amit; Rao, Murali; Sharma, Abhimanyu; Talwar, Sangeeta

2016-01-01

Background Complete removal of old filling material during root canal retreatment is fundamental for predictable cleaning and shaping of canal anatomy. Most of the retreatment methods tested in earlier studies have shown inability to achieve complete removal of root canal filling. Therefore the aim of this investigation was to assess the efficacy of three different rotary nickel titanium retreatment systems and Hedstrom files in removing filling material from root canals. Material and Methods Sixty extracted mandibular premolars were decoronated to leave 15 mm root. Specimen were hand instrumented and obturated using gutta percha and AH plus root canal sealer. After storage period of two weeks, roots were retreated with three (Protaper retreatment files, Mtwo retreatment files, NRT GPR) rotary retreatment instrument systems and Hedstroem files. Subsequently, samples were sectioned longitudinally and examined under stereomicroscope. Digital images were recorded and evaluated using Digital Image Analysing Software. The retreatment time was recorded for each tooth using a stopwatch. The area of canal and the residual filling material was recorded in mm2 and the percentage of remaining filling material on canal walls was calculated. Data was analysed using ANOVA test. Results Significantly less amount of residual filling material was present in protaper and Mtwo instrumented teeth (p < 0.05) compared to NRT GPR and Hedstrom files group. Protaper instruments also required lesser time during removal of filling material followed by Mtwo instruments, NRT GPR files and Hedstrom files. Conclusions None of the instruments were able to remove the filling material completely from root canal. Protaper universal retreatment system and Mtwo retreatment files were more efficient and faster compared to NRT GPR fles and Hedstrom files. Key words:Gutta-percha removal, nickel titanium, root canal retreatment, rotary instruments. PMID:27703601

Comparative Evaluation of Marginal Adaptation of BiodentineTM and Other Commonly Used Root End Filling Materials-An Invitro Study

PubMed Central

P.V., Ravichandra; Vemisetty, Harikumar; K., Deepthi; Reddy S, Jayaprada; D., Ramkiran; Krishna M., Jaya Nagendra; Malathi, Gita

2014-01-01

Aim: The purpose of this investigation was to evaluate the marginal adaptation of three root-end filling materials Glass ionomer cement, Mineral trioxide aggregate and BiodentineTM. Methodology: Thirty human single-rooted teeth were resected 3 mm from the apex. Root-end cavities were then prepared using an ultrasonic tip and filled with one of the following materials Glass ionomer cement (GIC), Mineral trioxide aggregate (MTA) and a bioactive cement BiodentineTM. The apical portions of the roots were then sectioned to obtain three 1 mm thick transversal sections. Confocal laser scanning microscopy (CLSM) was used to determine area of gaps and adaptation of the root-end filling materials with the dentin. The Post hoc test, a multiple comparison test was used for statistical data analysis. Results: Statistical analysis showed lowest marginal gaps (11143.42±967.753m2) and good marginal adaptation with BiodentineTM followed by MTA (22300.97±3068.883m2) and highest marginal gaps with GIC (33388.17±12155.903m2) which were statistically significant (p<0.0001). Conclusion: A new root end filling material BiodentineTM showed better marginal adaptation than commonly used root end filling materials PMID:24783148

Radiographic technical quality of root canal treatment performed by a new rotary single-file system.

PubMed

Colombo, Marco; Bassi, Cristina; Beltrami, Riccardo; Vigorelli, Paolo; Spinelli, Antonio; Cavada, Andrea; Dagna, Alberto; Chiesa, Marco; Poggio, Claudio

2017-01-01

The aim of the present study was to evaluate radiographically the technical quality of root canal filling performed by postgraduate students with a new single-file Nickel-Titanium System (F6 Skytaper Komet) in clinical practice. Records of 74 patients who had received endodontic treatment by postgraduate students at the School of Dentistry, Faculty of Medicine, University of Pavia in the period between September 2015 and April 2016 were collected and examined: the final sample consisted 114 teeth and 204 root canals. The quality of endodontic treatment was evaluated by examining the length of the filling in relation to the radiographic apex, the density of the obturation according to the presence of voids and the taper of root canal filling. Chi-squared analysis was used to determine statistically significant differences between the technical quality of root fillings according to tooth's type, position and curvature. The results showed that 75,49%, 82,84% and 90,69% of root filled canals had adequate length, density and taper respectively. Overall, the technical quality of root canal fillings performed by postgraduates students was acceptable in 60,78% of the cases.

Evaluation of hydroxyl ion diffusion in dentin and injectable forms and a simple powder-water calcium hydroxide paste: an in vitro study.

PubMed

Eftekhar, Behrooz; Moghimipour, Eskandar; Eini, Ebrahim; Jafarzadeh, Mansour; Behrooz, Narges

2014-08-01

Intra canal medicaments are used to reduce the number of bacteria and reinfection in endodontic procedures. Calcium Hydroxide was introduced to endodontics by Herman as an intracanal antimicrobial agent. The aim of this study was to present an injectable formulation of calcium hydroxide then compare the final pH of this new formulation with Metapaste and evaluate the effect of a mixture of Calcium Hydroxide powder with water on human extracted teeth. A total of 49 extracted human single-canal roots without caries and visible microcracks were included in this study. The teeth were decoronated and length of teeth was measured 1 mm anatomic apex. The canals were prepared using step-back technique. A cavity was created in the middle third of the buccal surface of all roots. The teeth were randomly divided into five groups: Group A (n = 15): In this group the root canals were filled with a mixture of calcium hydroxide powder and distilled water. Group B (n = 15): Included roots that were filled with Metapaste. Group C (n = 15): Root canals of this group were filled with new formulation of calcium hydroxide paste. Group D (negative control, n = 2): Included roots that were filled with a mixture of calcium hydroxide powder and distilled water. Group E (positive control, n = 2): Root canals of this group were filled with a mixture of calcium hydroxide powder and distilled water. Each tooth was immersed in a separate closed container with 4 mL saline for 2 weeks, pH of liquids were measured with an electrical pH meter after 7 and 14 days. The SPSS software (version 13) was used for data analysis. Analysis of variance (ANOVA) and Tukey tests were used for the statistical evaluation of results. There was no significant difference at 7th day between the groups (P = 0.17) but at 14th day, a significant difference was observed between the groups (P = 0.04). The new formulation of calcium hydroxide with methylcellulose base has slower ionic dissolution, more durability and longevity of alkaline properties in comparison to combination of powder with distilled water and is comparable with other commercial products.

Healing of experimental apical periodontitis after apicoectomy using different sealing materials on the resected root end.

PubMed

Otani, Kaori; Sugaya, Tsutomu; Tomita, Mahito; Hasegawa, Yukiko; Miyaji, Hirofumi; Tenkumo, Taichi; Tanaka, Saori; Motoki, Youji; Takanawa, Yasuhiro; Kawanami, Masamitsu

2011-01-01

This study evaluated apical periodontal healing after root-end sealing using 4-META/MMA-TBB resin (SB), and root-end filling using reinforced zinc oxide eugenol cement (EBA) or mineral trioxide aggregate (MTA) when root canal infection persisted. Apical periodontitis was induced in mandibular premolars of beagles by contaminating the root canals with dental plaque. After 1 month, in the SB group, SB was applied to the resected surface following apicoectomy. In the EBA and MTA groups, a root-end cavity was prepared and filled with EBA or MTA. In the control group, the root-end was not filled. Fourteen weeks after surgery, histological and radiographic analyses in a beagle model were performed. The bone defect area in the SB, EBA and MTA groups was significantly smaller than that in the control group. The result indicated that root-end sealing using SB and root-end filling using EBA or MTA are significantly better than control.

Prevalence of apical periodontitis and quality of root canal treatment in an adult Palestinian sub-population

PubMed Central

Mukhaimer, Raed; Hussein, Emad; Orafi, Ibtesam

2012-01-01

Purpose The aim of this study was to determine the prevalence of apical periodontitis and the technical quality of root canal fillings in a Palestinian sub-population. Methods The panoramic radiographs of 258 patients (142 females, 116 males) attending dental clinics in 2010 were examined to identify the presence of apical lesions associated with any remaining teeth, excluding third molars. The technical quality of root canal fillings was also evaluated by assessing apical extension from the radiographic apex. The panoramic radiographs were taken by a well-trained radiology assistant and evaluated by a radiologist and an endodontist. Statistical analysis was performed with the chi-square test with a significant level set at P < 0.05%. Results Of 6482 teeth examined radiographically, 978 (15.1%) had radiographic signs of apical periodontitis (AP). The prevalence of AP was 8.3% in teeth without filled roots and 59.5% (509/855) in root canal-treated teeth. The prevalence of AP and endodontic treatment increased with age and differed significantly (p < 0.05) between males and females. The majority (74.5%) of root canal fillings was performed inadequately, and most (77.2%) inadequate fillings were >2 mm short of the radiographic apex. The presence of AP was correlated significantly with poorly executed root canal fillings (p < 0.05). Conclusions The present study found a high prevalence and incidence of AP in association with root-filled teeth. The technical quality of many root canal treatments was unacceptable. PMID:23960544

Marginal adaptation of mineral trioxide aggregate (MTA) compared with amalgam as a root-end filling material: a low-vacuum (LV) versus high-vacuum (HV) SEM study.

PubMed

Shipper, G; Grossman, E S; Botha, A J; Cleaton-Jones, P E

2004-05-01

To compare the marginal adaptation of mineral trioxide aggregate (MTA) or amalgam root-end fillings in extracted teeth under low-vacuum (LV) versus high-vacuum (HV) scanning electron microscope (SEM) viewing conditions. Root-end fillings were placed in 20 extracted single-rooted maxillary teeth. Ten root ends were filled with MTA and the other 10 root ends were filled with amalgam. Two 1 mm thick transverse sections of each root-end filling were cut 0.50 mm (top) and 1.50 mm (bottom) from the apex. Gap size was recorded at eight fixed points along the dentine-filling material interface on each section when uncoated wet (LV wet (LVW)) and dry under LV (0.3 Torr) in a JEOL JSM-5800 SEM and backscatter emission (LV dry uncoated (LVDU)). The sections were then air-dried, gold-coated and gap size was recorded once again at the fixed points under HV (10(-6) Torr; HV dry coated (HVDC)). Specimen cracking, and the size and extent of the crack were noted. Gap sizes at fixed points were smallest under LVW and largest under HVDC SEM conditions. Gaps were smallest in MTA root-end fillings. A General Linear Models Analysis, with gap size as the dependent variable, showed significant effects for extent of crack in dentine, material and viewing condition (P = 0.0001). This study showed that MTA produced a superior marginal adaptation to amalgam, and that LVW conditions showed the lowest gap size. Gap size was influenced by the method of SEM viewing. If only HV SEM viewing conditions are used for MTA and amalgam root-end fillings, a correction factor of 3.5 and 2.2, respectively, may be used to enable relative comparisons of gap size to LVW conditions.

To evaluate the influence of smear layer with different instruments and obturation methods on microleakage of root canal filled teeth: In vitro study.

PubMed

Likhitkar, Manoj S; Kulkarni, Shantaram V; Burande, Aravind; Solanke, Vishal; Kumar, C Sushil; Kamble, Babasaheb

2016-01-01

The success of root canal treatment depends on proper debridement, instrumentation, proper accessibility, and proper restoration. The presence of a smear layer is considered to be a significant factor. This in vitro study was conducted to assess the effect of the presence/absence of a smear layer on the microleakage of root canal filled teeth using different instruments and obturation methods. One hundred extracted mandibular premolars with closed apices and single roots were chosen and then divided into six groups, A to F, consisting of 15 teeth each. The control group included 10 teeth; 5 positive and 5 negative. The teeth were decoronated at the cementoenamel junction. Groups A, B, C, and D were instrumented with engine-driven rotary Protaper NiTi files. Groups E and F were instrumented with conventional stainless steel hand files. Groups A, C, and E were flushed with 3 ml of 17% EDTA to remove the smear layer prior to obturation. All teeth were flushed with 5.25% sodium hypochlorite solution and obturated with AH-Plus sealer with lateral condensation technique for Groups C, D, E, F and with thermoplasticized gutta-percha technique for Groups A and B. Using an electrochemical technique, leakages in the obturated canals were assessed for 45 days. The results were tabulated using Student's t-test (paired and unpaired t-test) with the Statistical Package for the Social Sciences Software Version 21 (IBM Company, New York, USA). Group A showed the lowest mean value at intervals of 10, 20, 30, and 45 days. There was no current flow in the negative controls during the test period. There was leakage in the positive controls within a few minutes of immersion. The results showed that rotary instrumentation contributed toward an exceptional preparation of root canals compared to hand instrumentation. Elimination of the smear layer enhanced the resistance to microleakage; thermoplasticized gutta-percha obturation technique produced a better seal compared to the lateral condensation technique.

Effect of photodynamic therapy and non-thermal plasma on root canal filling: analysis of adhesion and sealer penetration

PubMed Central

MENEZES, Marilia; PRADO, Maíra; GOMES, Brenda; GUSMAN, Heloisa; SIMÃO, Renata

2017-01-01

Abstract Objective The aim of this study was to evaluate the effect of photodynamic therapy (PDT) and non-thermal plasma (NTP) on adhesion and sealer penetration in root canals. Material and Methods Sixty single-rooted premolars were used. The teeth were prepared using a crown-down technique. NaOCl and EDTA were used for irrigation and smear layer removal, respectively. The root canals were divided into three groups: control, PDT, and NTP. After treatments, the roots were filled using gutta-percha and either AH Plus (AHP) or MTA Fillapex (MTAF) sealers. Samples were sectioned at 4, 8, and 12 mm from the apex (1-mm slices)and analyzed by the push-out bond strength test (adhesion) and confocal laser scanning microscopy (sealer penetration). Data were statistically evaluated using Kruskal-Wallis, Dunn’s, and Spearman’s tests. Results Regarding AHP, bond strength was similar in the NTP group and in the control group, but significantly lower in the PDT group. As to MTAF, both therapies showed lower values than the control group. In the confocal analysis of AHP, maximum and mean penetration, and penetrated area were statistically higher in the control group than in the PDT and NTP groups. Penetrated perimeter was similar among groups. Regarding MTAF, all parameters yielded better results in the NTP than in the control group. The PDT and control groups showed similar results except for penetrated area. Conclusion PDT and plasma therapy affected the adhesion and sealer penetration of root canals filled with AH Plus and MTA Fillapex and there is no positive correlation between adhesion and sealer penetration. PMID:28877278

Evaluation of Enterococcus faecalis adhesion, penetration, and method to prevent the penetration of Enterococcus faecalis into root cementum: Confocal laser scanning microscope and scanning electron microscope analysis.

PubMed

Halkai, Rahul S; Hegde, Mithra N; Halkai, Kiran R

2016-01-01

To ascertain the role of Enterococcus faecalis in persistent infection and a possible method to prevent the penetration of E. faecalis into root cementum. One hundred and twenty human single-rooted extracted teeth divided into five groups. Group I (control): intact teeth, Group II: no apical treatment done, Group III divided into two subgroups. In Groups IIIa and IIIb, root apex treated with lactic acid of acidic and neutral pH, respectively. Group IV: apical root cementum exposed to lactic acid and roughened to mimic the apical resorption. Group V: apical treatment done same as Group IV and root-end filling done using mineral trioxide aggregate (MTA). Apical one-third of all samples immersed in E. faecalis broth for 8 weeks followed by bone morphogenetic protein and obturation and again immersed into broth for 8 weeks. Teeth split into two halves and observed under confocal laser scanning microscope and scanning electron microscope, organism identified by culture and polymerase chain reaction techniques. Adhesion and penetration was observed in Group IIIa and Group IV. Only adhesion in Group II and IIIB and no adhesion and penetration in Group I and V. Adhesion and penetration of E. faecalis into root cementum providing a long-term nidus for subsequent infection are the possible reason for persistent infection and root-end filling with MTA prevents the adhesion and penetration.

Prevalence of apical periodontitis and quality of root canal fillings in population of Zagreb, Croatia: a cross-sectional study

PubMed Central

Matijević, Jurica; Čižmeković Dadić, Tina; Prpić Mehičić, Goranka; Anić, Ivica; Šlaj, Mladen; Jukić Krmek, Silvana

2011-01-01

Aim To determine the prevalence of apical periodontitis and assess the quality of endodontic fillings in the population of the city of Zagreb, Croatia. Methods A total of 1462 orthopantomograms from new patients at 6 different dental practices was analyzed during 2006 and 2007. The presence of periapical lesions was determined by using the periapical index score (PAI). The quality of endodontic fillings was assessed according to the filling length and homogeinicity. Data were analyzed using t test and ANOVA with Scheffe post-hoc test. Results There were 75.9% of participants with endodontically treated teeth and 8.5% of all teeth were endodontically treated. Only 34.2% of endodontically treated roots had adequate root canal filling length, while 36.2% of root canal fillings had homogenous appearance. From the total number of teeth with intracanal post, 17.5% had no visible root canal filling. Using PAI 3 as a threshold value for apical periodontitis, periapical lesions were detected in 8.5% of teeth. Adequate quality of root canal fillings was associated with a lower prevalence of periapical lesions. Conclusion We found a large proportion of endodontically treated teeth with apical periodontitis and a correlation between the quality of endodontic filling and the prevalence of periapical lesions. This all suggests that it is necessary to improve the quality of endodontic treatment in order to reduce the incidence and prevalence of apical periodontitis. PMID:22180266

Prevalence of periradicular periodontitis in a Scottish subpopulation found on CBCT images.

PubMed

Dutta, A; Smith-Jack, F; Saunders, W P

2014-09-01

To investigate the prevalence of periradicular periodontitis (PRP) using cone-beam computed tomography (CBCT) scans in a retrospective cross-sectional epidemiological study in a Scottish subpopulation. Of the 319 CBCT scans performed at Dundee Dental Hospital between November 2009 and July 2012, 245 dentate scans of patients over 18 years of age were included and 3595 teeth examined. Odds ratios were calculated, and the association between root filling and posts with PRP was determined. Radiological signs of PRP were detected in 209 teeth (5.8%) in 96 patients (male = 53, female = 43) of which 145 (69.4%) were measurable and 64 (30.6%) appeared as periapical widening. Most lesions were seen in the 46-55-year age group and in maxillary anterior teeth (35.4%); 47.4% (n = 81) of the total root filled teeth (n = 171) had PRP. Of the root filled teeth with lesions, approximately half (50.6%) had an inadequate root filling. Teeth with crowns, but not root filled, accounted for 17.7% of PRP. Periapical changes were detected on a high proportion of teeth with post-retained crowns (70.7%). The presence of a root filling was significantly associated with PRP (z = 17.689 P < 0.0001; odds ratio 16.36 < 23.17 < 32.83, 95% CI) and the presence of a post (z = 10.901 P < 0.0001; odds ratio 21.36 < 41.8021 < 81.78, 95% CI). The prevalence of PRP in a Scottish subpopulation was 5.8%. The presence of a root filling or a post-retained crown was significantly associated with the presence of PRP as determined by CBCT scans. The prevalence of periradicular disease in root filled teeth remains high in the Scottish population. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

'It's good enough': Swedish general dental practitioners on reasons for accepting substandard root filling quality.

PubMed

Dahlström, L; Lindwall, O; Rystedt, H; Reit, C

2018-04-01

The concept of 'good enough' is central and necessary in the assessment of root filling quality. The aim was to explore the concept by analysing reasons and arguments for the acceptance or rejection of substandard root filling quality as reported by general dental practitioners (GDPs) in Sweden. The study was designed as a qualitative and exploratory study based on seven videotaped focus group interviews analysed by means of qualitative content analysis. Thirty-three GDPs employed in the Public Dental Health Service in Gothenburg, Sweden, participated (4-6 GDPs/interview). In all, nine predetermined questions were followed. Before each focus group, the participants received radiographs of 37 root fillings and were asked to assess the root filling quality. The three cases representing the most divergent assessments served as a basis for the discussion. The cases were presented without clinical information; the dentists would relate to the cases as being just root filled by themselves. The radiographs did not provide a sufficient basis for decisions on whether or not to accept the root filling. This study emphasized that dentists did not primarily look for these arguments in the technical details of the root filling per se, but instead, they considered selected features of the contextual situation. The GDPs constantly introduced relevant 'ad hoc considerations' to account for the decisions they made. These contextual considerations were related to aspects of pulpal and periapical disease, risks (e.g. technical complications) or to consumed resources (personal and/or economic). It was obvious that the concept of 'good enough' does not exist as a general formula ready to be applied in particular situations. Instead, it is necessarily and irremediably tied to contextual properties that emerge from case to case. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Impact of the quality of coronal restoration and root canal filling on the periapical health in adult syrian subpopulation

PubMed Central

Alafif, Hisham

2014-01-01

Background: The purpose of this study was to determine the status of periapical tissues of endodontically treated teeth according to coronal restorations and root canal fillings separately and in concomitant in adult Syrian subpopulation. Methods: 784 endodontically treated teeth from two hundred randomly selected Syrian adult patients were radiographically evaluated. According to predetermined criteria, the quality of coronal restorations and root canal filling of each tooth was scored as adequate or inadequate. The status of periapical tissues was also classified as healthy or diseased. Results were analyzed using Chi-squared test. Results: Adequate coronal restorations were determined in 58.54% of cases which was accompanied with less periapical pathosis than that in teeth with inadequate restorations (P < 0.01). 14% of teeth were restored by posts which showed no significant impact on the periapical tissues health. 18.5% of endodontic treatments were evaluated as adequate with less number of periapical radiolucencies than that of inadequate root canal fillings (P < 0.01). Absence of periapical pathosis was 96.6% in cases with both adequate coronal restorations and root canals fillings. The rate was 88.5% in cases with only adequate root canals fillings, and about 70% in cases with only adequate coronal restorations. When the treatment was inadequate in both coronal and root canals fillings, success rate was only observed in 48.8%. Conclusion: The most important factor with regard to the periradicular tissue health is the quality of root canal filling without neglecting the influence of coronal restoration (regardless of its type). There is a high prevalence rate of periapical pathosis in Syrian subpopulation due to poor dental practice. PMID:25565729

Periapical tissue response after use of intermediate restorative material, gutta-percha, reinforced zinc oxide cement, and mineral trioxide aggregate as retrograde root-end filling materials: a histologic study in dogs.

PubMed

Wälivaara, Dan-Åke; Abrahamsson, Peter; Isaksson, Sten; Salata, Luiz Antonio; Sennerby, Lars; Dahlin, Christer

2012-09-01

To investigate the periapical tissue response of 4 different retrograde root-filling materials, ie, intermediate restorative material, thermoplasticized gutta-percha, reinforced zinc oxide cement (Super-EBA), and mineral trioxide aggregate (MTA), in conjunction with an ultrasonic root-end preparation technique in an animal model. Vital roots of the third and fourth right mandibular premolars in 6 healthy mongrel dogs were apicectomized and sealed with 1 of the materials using a standardized surgical procedure. After 120 days, the animals were sacrificed and the specimens were analyzed radiologically, histologically, and scanning electron microscopically. The Fisher exact test was performed on the 2 outcome values. Twenty-three sections were analyzed histologically. Evaluation showed better re-establishment of the periapical tissues and generally lower inflammatory infiltration in the sections from teeth treated with the intermediate restorative material and the MTA. New root cement on the resected dentin surfaces was seen on all sections regardless of the used material. New hard tissue formation, directly on the surface of the material, was seen only in the MTA sections. There was no statistical difference in outcome among the tested materials. The results from this dog model favor the intermediate restorative material and MTA as retrograde fillings when evaluating the bone defect regeneration. MTA has the most favorable periapical tissue response when comparing the biocompatibility of the materials tested. Copyright © 2012 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

The efficacy of the Self-Adjusting File versus WaveOne in removal of root filling residue that remains in oval canals after the use of ProTaper retreatment files: A cone-beam computed tomography study

PubMed Central

Pawar, Ajinkya M; Thakur, Bhagyashree; Metzger, Zvi; Kfir, Anda; Pawar, Mansing

2016-01-01

Aim: The current ex vivo study compared the efficacy of removing root fillings using ProTaper retreatment files followed by either WaveOne reciprocating file or the Self-Adjusting File (SAF). Materials and Methods: Forty maxillary canines with single oval root canal were selected and sectioned to obtain 18-mm root segments. The root canals were instrumented with WaveOne primary files, followed by obturation using warm lateral compaction, and the sealer was allowed to fully set. The teeth were then divided into two equal groups (N = 20). Initial removal of the bulk of root filling material was performed with ProTaper retreatment files, followed by either WaveOne files (Group 1) or SAF (Group 2). Endosolv R was used as a gutta-percha softener. Preoperative and postoperative high-resolution cone-beam computed tomography (CBCT) was used to measure the volume of the root filling residue that was left after the procedure. Statistical analysis was performed using t-test. Results: The mean volume of root filling residue in Group 1 was 9.4 (±0.5) mm3, whereas in Group 2 the residue volume was 2.6 (±0.4) mm3, (P < 0.001; t-test). Conclusions: When SAF was used after ProTaper retreatment files, significantly less root filling residue was left in the canals compared to when WaveOne was used. PMID:26957798

The Tennessee study: factors affecting treatment outcome and healing time following nonsurgical root canal treatment.

PubMed

Azim, A A; Griggs, J A; Huang, G T-J

2016-01-01

To determine factors that may influence treatment outcome and healing time following root canal treatment. Root filled and restored teeth by pre-doctoral students were included in this study. Teeth/roots were followed-up regularly, and treatment outcome was evaluated at every follow-up appointment (healed, healing, uncertain or unsatisfactory). Host (age, immune condition, pulp/periapical diagnosis, tooth/root type, location and anatomy) and treatment factors (master apical file size, apical extension, voids and density of root filling) were recorded from patient dental records. Univariate, bivariate and multivariate analyses were performed to determine the impact of the factors on treatment outcomes and healing times. A total of 422 roots from 291 teeth met the inclusion criteria with a mean follow-up period of 2 years. The preoperative pulp condition, procedural errors during treatment, apical extension and density of root fillings significantly affected the treatment outcome. The average time required for a periapical lesion to heal was 11.78 months. The healing time increased in patients with compromised healing, patients older than 40 years, roots with Weine type II root canal systems, root canal systems prepared to a master apical file size <35, and roots with overextended fillings (P < 0.1). Multiple host and treatment factors affected the healing time and outcome of root canal treatment. Follow-up protocols should consider these factors before concluding the treatment outcome: patient's age, immune condition, as well as roots with overextended fillings, root canal systems with smaller apical preparations (size <35) or roots with complex canal systems. Intervention may be recommended if the treatment quality was inadequate or if patients became symptomatic. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Evaluation of technical quality and periapical health of root-filled teeth by using cone-beam CT

PubMed Central

Bilge Gülsüm, NUR; Evren, OK; ALTUNSOY, Mustafa; AĞLARCI, Osman Sami; ÇOLAK, Mehmet; GÜNGÖR, Enes

2014-01-01

Objective This study aimed to assess the quality of root fillings, coronal restorations, complications of all root-filled teeth and their association with apical periodontitis (AP) detected by cone-beam computed tomography (CBCT) images from an adult Turkish subpopulation. Material and Methods The sample for this study consisted of 242 patients (aging from 15 to 72 years) with 522 endodontically treated teeth that were assessed for technical quality of the root canal filling and periapical status of the teeth. Additionally, the apical status of each root-filled tooth was assessed according to the gender, dental arch, tooth type and age classification, undetected canals, instrument fracture, root fracture, apical resorption, apical lesion, furcation lesion and type and quality of the coronal structure. Statistical analysis was performed using percentages and chi-square test. Results The success rate of the root canal treatment was of 54.4%. The success rates of adequate and inadequate root canal treatment were not significantly different (p>0.05). Apical periodontitis was found in 228 (45.6%) teeth treated for root canals. Higher prevalence of AP was found in patients aging from 20 to 29 years [64 (27%) teeth] and in anterior (canines and incisors) teeth [97 (41%) teeth]. Conclusions The technical quality of root canal filling performed by dental practitioners in a Turkish subpopulation was consistent with a high prevalence of AP. The probable reasons for this failure are multifactorial, and there may be a need for improved undergraduate education and postgraduate courses to improve the clinical skills of dental practitioners in endodontics. PMID:25591019

Effect of ultrasonic tip and root-end filling material on bond strength.

PubMed

Vivan, Rodrigo Ricci; Guerreiro-Tanomaru, Juliane Maria; Bernardes, Ricardo Affonso; Reis, José Mauricio Santos Nunes; Hungaro Duarte, Marco Antonio; Tanomaru-Filho, Mário

2016-11-01

The objective of this study was to evaluate the bond strength of three root-end filling materials (MTAA-MTA Angelus, MTAS-experimental MTA Sealer, and ZOE- zinc oxide and eugenol cement) in retrograde preparations performed with different ultrasonic tips (CVD, Trinity, and Satelec). Ninety 2-mm root sections from single-rooted human teeth were used. The retrograde cavities were prepared by using the ultrasonic tips, coupled to a device for position standardization. The specimens were randomly divided into nine groups: CVD MTAA; CVD MTAS; CVD ZOE; Trinity MTAA; Trinity MTAS; Trinity ZOE; Satelec MTAA; Satelec MTAS; Satelec ZOE. Each resin disc/dentin/root-end filling material was placed in the machine to perform the push-out test. The specimens were examined in a stereomicroscope to evaluate the type of failure. Data were submitted to statistical analysis using ANOVA and Tukey tests (α = 0.05). The highest bond strength was observed for the CVD tip irrespective of the material used (P < 0.05). There was no significant difference for the Trinity TU-18 diamond and S12 Satelec tips (P > 0.05). MTAA and MTAS showed highest bond strength. The most common type of failure was adhesion between the filling material and dentin wall, except for ZOE, where mixed failure was predominant. The CVD tip favored higher bond strength of the root-end filling materials. MTA Angelus and experimental MTAS presented bond strength to dentin prepared with ultrasonic tips. Root-end preparation with the CVD tip positively influences the bond strength of root-end filling materials. MTA Angelus and experimental MTAS present bond strength to be used as root-end filling materials.

Single crowns versus conventional fillings for the restoration of root filled teeth.

PubMed

Fedorowicz, Zbys; Carter, Ben; de Souza, Raphael Freitas; Chaves, Carolina de Andrade Lima; Nasser, Mona; Sequeira-Byron, Patrick

2012-05-16

Endodontic treatment, involves removal of the dental pulp and its replacement by a root canal filling. Restoration of root filled teeth can be challenging due to structural differences between vital and non-vital root filled teeth. Direct restoration involves placement of a restorative material e.g. amalgam or composite directly into the tooth. Indirect restorations consist of cast metal or ceramic (porcelain) crowns. The choice of restoration depends on the amount of remaining tooth which may influence long term survival and cost. The comparative in service clinical performance of crowns or conventional fillings used to restore root filled teeth is unclear. To assess the effects of restoration of endodontically treated teeth (with or without post and core) by crowns versus conventional filling materials. We searched the following databases: the Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE via OVID, EMBASE via OVID, CINAHL via EBSCO, LILACS via BIREME and the reference lists of articles as well as ongoing trials registries.There were no restrictions regarding language or date of publication. Date of last search was 13 February 2012. Randomised controlled trials (RCTs) or quasi-randomised controlled trials in participants with permanent teeth which have undergone endodontic treatment. Single full coverage crowns compared with any type of filling materials for direct restoration, as well as indirect partial restorations (e.g. inlays and onlays). Comparisons considered the type of post and core used (cast or prefabricated post), if any. Two review authors independently assessed trial quality and extracted data. One trial judged to be at high risk of bias due to missing outcome data, was included. 117 participants with a root filled premolar tooth restored with a carbon fibre post, were randomised to either a full coverage metal-ceramic crown or direct adhesive composite restoration. At 3 years there was no reported difference between the non-catastrophic failure rates in both groups. Decementation of the post and marginal gap formation occurred in a small number of teeth. There is insufficient evidence to support or refute the effectiveness of conventional fillings over crowns for the restoration of root filled teeth. Until more evidence becomes available clinicians should continue to base decisions on how to restore root filled teeth on their own clinical experience, whilst taking into consideration the individual circumstances and preferences of their patients.

Evaluation of lumbar transforaminal epidural injections with needle placement and contrast flow patterns: a prospective, descriptive report.

PubMed

Manchikanti, Laxmaiah; Cash, Kim A; Pampati, Vidyasagar; Damron, Kim S; McManus, Carla D

2004-04-01

Transforaminal epidural steroid injection is one of the commonly employed modalities of treatment in managing nerve root pain. However, there have been no controlled prospective evaluations of epidural and nerve root contrast distribution patterns and other aspects of fluoroscopically directed lumbosacral transforaminal epidural steroid injections. To evaluate contrast flow patterns and intravascular needle placement of fluoroscopically guided lumbosacral transforaminal epidural injections. A prospective, observational study. A total of 100 consecutive patients undergoing fluoroscopically guided transforaminal epidural steroid injections were evaluated. The contrast flow patterns, ventral or dorsal epidural filling, nerve root filling, C-arm time, and intravascular needle placement were evaluated. Ventral epidural filling was seen in 88% of the procedures, in contrast to dorsal filling noted in 9% of the procedures. Nerve root filling was seen in 97% of the procedures. Total intravenous placement of the needle was noted in 22% of the procedures, whereas negative flashback and aspiration was noted in 5% of the procedures. Lumbosacral transforaminal epidural injections, performed under fluoroscopic visualization, provide excellent nerve root filling and ventral epidural filling patterns. However, unrecognized intravascular needle placement with negative flashback or aspiration was noted in 5% of the procedures.

Theoretical distribution of gutta-percha within root canals filled using cold lateral compaction based on numeric calculus.

PubMed

Min, Yi; Song, Ying; Gao, Yuan; Dummer, Paul M H

2016-08-01

This study aimed to present a new method based on numeric calculus to provide data on the theoretical volume ratio of voids when using the cold lateral compaction technique in canals with various diameters and tapers. Twenty-one simulated mathematical root canal models were created with different tapers and sizes of apical diameter, and were filled with defined sizes of standardized accessory gutta-percha cones. The areas of each master and accessory gutta-percha cone as well as the depth of their insertion into the canals were determined mathematically in Microsoft Excel. When the first accessory gutta-percha cone had been positioned, the residual area of void was measured. The areas of the residual voids were then measured repeatedly upon insertion of additional accessary cones until no more could be inserted in the canal. The volume ratio of voids was calculated through measurement of the volume of the root canal and mass of gutta-percha cones. The theoretical volume ratio of voids was influenced by the taper of canal, the size of apical preparation and the size of accessory gutta-percha cones. Greater apical preparation size and larger taper together with the use of smaller accessory cones reduced the volume ratio of voids in the apical third. The mathematical model provided a precise method to determine the theoretical volume ratio of voids in root-filled canals when using cold lateral compaction.

Push-out bond strength of different tricalcium silicate-based filling materials to root dentin.

PubMed

Stefaneli Marques, Jorge Henrique; Silva-Sousa, Yara Teresinha Corrêa; Rached-Júnior, Fuad Jacob Abi; Macedo, Luciana Martins Domingues de; Mazzi-Chaves, Jardel Francisco; Camilleri, Josette; Sousa-Neto, Manoel Damião

2018-03-08

The aim of this study was to evaluate the bond strength of different triccalcium silicate cements to retrograde cavity using a push out test. Thirty maxillary central incisors were shaped using #80 hand files and sectioned transversally. Root slices were obtained from the apical 4 mm after eliminating the apical extremity. The specimens were embedded in acrylic resin and positioned at 45° to the horizontal plane for preparation of root-end cavities with a diamond ultrasonic retrotip. The samples were divided into three groups according to the root-end filling material (n = 10): MTA Angelus, ProRoot MTA and Biodentine. A gutta-percha cone (#80) was tugged-back at the limit between the canal and the root-end cavity. The root-end cavity was filled and the gutta-percha cone was removed after complete setting of the materials. The specimens were placed in an Instron machine with the root-end filling turned downwards. The push-out shaft was inserted in the space previously occupied by the gutta-percha cone and push out testing was performed at a crosshead speed of 1.0 mm/min. There was no statistically significant difference in resistance to push out by the materials tested (p > 0.01). MTA Angelus and ProRoot MTA showed predominantly mixed failure while Biodentine exhibited mixed and cohesive failures. The tricalcium silicate-based root-end filling materials showed similar bond strength retrograde cavity.

Comparison of two vertical condensation obturation techniques: Touch 'n Heat modified and System B.

PubMed

Silver, G K; Love, R M; Purton, D G

1999-08-01

The aims of this study were firstly to compare the area of canal occupied by gutta-percha, sealer or voids using the System B heating device with that obtained by a modified vertical condensation technique using the Touch 'n Heat: and secondly to compare the temperature changes at the root canal wall and external root surface during obturation with the above techniques. Forty-five resin blocks, each with a standardized, simulated, prepared main root canal and five lateral canals, were assigned to three equal experimental groups. The canals were obturated using either the System B technique at two different temperature settings, or vertical condensation with a Touch 'n Heat instrument as the heat source. A heat transfer model was used to simultaneously record internal and external root surface temperature elevations during obturation by the three techniques. Data were analysed using unpaired Student's t-test and Mann-Whitney U-test. Both obturation techniques produced root fillings consisting of over 90% gutta-percha at most levels, although the percentages of sealer and voids 2-3 mm from the working length following System B obturation were higher than those found following modified vertical condensation. Modified vertical condensation resulted in more gutta-percha in lateral canals. Obturation was accomplished more quickly using the System B, and temperature elevations produced during obturation with the System B were significantly less (P < 0.001) than with vertical condensation. An elevation of external root surface temperature by more than 10 degrees C occurred during vertical condensation. The results suggest that the System B may produce an acceptable obturation and that the use of a Touch 'n Heat source during vertical condensation may result in damage to the periodontium.

Nonsurgically retreated root filled teeth--radiographic findings after 20-27 years.

PubMed

Fristad, I; Molven, O; Halse, A

2004-01-01

To identify periapical changes in nonsurgically retreated root-filled teeth 20-27 years after root canal treatment. From an original material of 429 roots, retreated by undergraduate students in a teaching clinic, 112 roots in 70 individuals could be evaluated radiographically 20-27 years after treatment. The same roots had been studied 10-17 years earlier. The periapical condition was registered and compared by three observers in two series of intraoral radiographs taken 10-17 and 20-27 years after treatment. A retrospective analysis was performed to gain information about probable endodontic and nonendodontic reasons for extractions of lost roots, by evaluating their periapical status immediately after retreatment and at the 10-17-year follow-up. Favourable outcomes were observed in 11 roots that had radiolucencies at the 10-17-year follow-up. Eight of these roots had periapical pathosis preoperatively, five of them filled with surplus root filling material. The percentage of cases recorded as normal condition at the final follow-up was 95.5%, including five cases initially recorded with increased width of the apical periodontal space. Delayed healing as a result of surplus root filling material explained most of the cases with favourable outcome assessed many years after treatment. Twenty-eight roots were lost because of extraction during the observation period, 17 during the last 10 years. Based on status at previous follow-ups, endodontic failure seems to represent a minor reason for extraction in the material. Late periapical changes, with more successful cases, were recorded when a 10-17-year follow-up after root canal treatment was extended for another 10 years. Persistent asymptomatic periapical radiolucencies, especially those with overfill, should generally not be classified as failures, as many of them will heal after an extended observation period.

Technical Quality of Root Canal Treatment Performed by Undergraduate Clinical Students of Isfahan Dental School.

PubMed

Saatchi, Masoud; Mohammadi, Golshan; Vali Sichani, Armita; Moshkforoush, Saba

2018-01-01

The aim of the present study was to evaluate the radiographic quality of RCTs performed by undergraduate clinical students of Dental School of Isfahan University of Medical Sciences. In this cross sectional study, records and periapical radiographs of 1200 root filled teeth were randomly selected from the records of patients who had received RCTs in Dental School of Isfahan University of Medical Sciences from 2013 to 2015. After excluding 416 records, the final sample consisted of 784 root-treated teeth (1674 root canals). Two variables including the length and the density of the root fillings were examined. Moreover, the presence of ledge, foramen perforation, root perforation and fractured instruments were also evaluated as procedural errors. Descriptive statistics were used for expressing the frequencies of criteria and chi square test was used for comparing tooth types, tooth locations and academic level of students ( P <0.05). The frequency of root canals with acceptable filling was 54.1%. Overfilling was found in 11% of root canals, underfilling in 8.3% and inadequate density in 34.6%. No significant difference was found between the frequency of acceptable root fillings in the maxilla and mandible ( P =0.072). More acceptable fillings were found in the root canals of premolars (61.3%) than molars (51.3%) ( P =0.001). The frequency of procedural errors was 18.6%. Ledge was found in 12.5% of root canals, foramen perforation in 2%, root perforation in 2.4% and fractured instrument in 2%. Procedural errors were more frequent in the root canals of molars (22.5%) than the anterior teeth (12.3%) ( P =0.003) and the premolars (9.5%) ( P <0.001). Technical quality of RCTs performed by clinical students was not satisfactory and incidence of procedural errors was considerable.

Efficacy of ProTaper and Mtwo Retreatment Files in Removal of Gutta-percha and GuttaFlow from Root Canals

PubMed Central

Khedmat, Sedigheh; Azari, Abbas; Shamshiri, Ahmad Reza; Fadae, Mehdi; Bashizadeh Fakhar, Hoorieh

2016-01-01

Introduction: The aim of this in vitro study was to compare the efficacy of ProTaper retreatment (ProTaper R) and Mtwo retreatment (Mtwo R) files in removing gutta-percha and GuttaFlow from endodontically treated straight root canals. Methods and Materials: The root canals of 60 human mandibular single-rooted premolars were prepared and randomly divided into two groups (n=30). In groups A and B the root canals were obturated using lateral condensation of gutta-percha plus AH 26 and GuttaFlow, respectively. The canal orifices were temporarily sealed and the roots were incubated for 3 months at 37ºC and 100% humidity. Primary cone-beam computed tomography (CBCT) images were taken after incubation period. The specimens in each group were randomly divided into two subgroups (n=15). ProTaper R files (D1, D2, and D3) were used in groups A1 and B1 while Mtwo R files (25/0.05 and 15/0.05) were used in groups A2 and B2. The time required to extirpate the root filling was also recorded. After retreatment, another CBCT scan was taken at the same position. The volume of remaining filling materials inside the canals was calculated before and after retreatment. The data was analyzed using the two-way ANOVA and independent t-test. Results: The remaining filling materials in the canals treated with ProTaper were less than Mtwo. The remaining volume of GuttaFlow was less than gutta-percha regardless of the system applied. Mtwo R files removed root fillings faster than ProTaper R. Conclusion: ProTaper R removed filling material more efficiently compared to Mtwo R which required less time to remove root filling material. PMID:27471528

Filling a Conical Cavity

NASA Astrophysics Data System (ADS)

Nye, Kyle; Eslam-Panah, Azar

2016-11-01

Root canal treatment involves the removal of infected tissue inside the tooth's canal system and filling the space with a dense sealing agent to prevent further infection. A good root canal treatment happens when the canals are filled homogeneously and tightly down to the root apex. Such a tooth is able to provide valuable service for an entire lifetime. However, there are some examples of poorly performed root canals where the anterior and posterior routes are not filled completely. Small packets of air can be trapped in narrow access cavities when restoring with resin composites. Such teeth can cause trouble even after many years and lead the conditions like acute bone infection or abscesses. In this study, the filling of dead-end conical cavities with various liquids is reported. The first case studies included conical cavity models with different angles and lengths to visualize the filling process. In this investigation, the rate and completeness at which a variety of liquids fill the cavity were observed to find ideal conditions for the process. Then, a 3D printed model of the scaled representation of a molar with prepared post spaces was used to simulate the root canal treatment. The results of this study can be used to gain a better understanding of the restoration for endodontically treated teeth.

The force required to fracture endodontically roots restored with various materials as intra-orifice barriers.

PubMed

Yasa, E; Arslan, H; Yasa, B; Akcay, M; Alsancak, M; Hatirli, H

2017-10-01

To evaluate the effect of various materials as intra-orifice barriers on the force required fracture roots. One hundred-thirty five mandibular premolars were decoronated and prepared up to size #40. The root canals were filled and randomly divided into two control and seven experimental groups (n = 15), as follows: Positive control group (the intra-orifice barrier cavity was not prepared), negative control group (the intra-orifice barrier cavity was prepared, but not filled), filling using glass ionomer cement, nano-hybrid composite resin, short fiber-reinforced composite, bulk-fill flowable composite, MTA Angelus, Micro Mega MTA or Biodentine. A fracture strength test was performed, and the data were analyzed using one-way ANOVA and Tukey's post hoc tests. Nano-hybrid composite, short fiber-reinforced composite, bulk-fill flow able composite, and glass ionomer cement increased the force required fracture the roots compared to the positive and negative control groups (P < 0.05). While MTA groups did not increase the force required fracture the roots compared to the control groups, Biodentine increased significantly. Within the limitations of the present study, the use of nano-hybrid composite, short fiber-reinforced composite, bulk-fill flowable composite, and glass ionomer cement as an intra-orifice barrier may be useful in reinforcing roots. MTA placement (MTA Angelus or Micro Mega MTA) did not significantly increase the fracture resistance of endodontically treated roots compared to the control groups, however Biodentine did.

Effect of Calcium Hydroxide, Chlorhexidine Digluconate and Camphorated Monochlorophenol on the Sealing Ability of Biodentine Apical Plug.

PubMed

Srivastava, Aastha Arora; Srivastava, Harshit; Prasad, Ashwini B; Raisingani, Deepak; Soni, Dileep

2016-06-01

Teeth with immature apex are managed by establishing an apical plug using various materials and techniques. However, the use of previously placed intracanal medicament may affect the sealing ability of permanent filling material used as an apical plug. To evaluate the effect of removal of previously placed Calcium Hydroxide, Chlorhexidine Digluconate and Camphorated Monochlorophenol as an intracanal medicament on the sealing ability of the Biodentine as an apical plug. A total of 72 recently extracted human permanent teeth with single root were selected and stored in saline at room temperature. The crown portion of each tooth was removed at the level of cemento enamel junction; 14mm root length was taken as standard length. All the roots were submerged in 20% sulphuric acid up to 3 mm from the apex, for four days for root resorption. One sample was cut longitudinally to look for root resorption under stereo microscope. The canal preparation was done; the roots were kept in moist gauze after instrumentation. A total of 71 roots were randomly divided into three groups. GROUP 1:Calcium hydroxide paste, GROUP 2: Chlorhexidine digluconate, GROUP 3: Camphorated Monochlorophenol (CMCP). The medicaments were removed with stainless steel hand files and 0.5% sodium hypochlorite irrigation. After removal of medicament Biodentine was placed in apical third of resorbed roots and the remaining portion of the canals was filled with gutta-percha. All the 71 roots were analysed with fluid filtration method for evaluating microleakage. Comparing all the three groups statistically there was no significant difference. The mean values were found more for group 1 followed by group 2 & 3. All the groups showed microleakage. Calcium hydroxide showed the maximum microleakage followed by Chlorhexidine digluconate and least with CMCP.

Assessment of Marginal Adaptation and Sealing Ability of Root Canal Sealers: An in vitro Study.

PubMed

Remy, Vimal; Krishnan, Vineesh; Job, Tisson V; Ravisankar, Madhavankutty S; Raj, C V Renjith; John, Seena

2017-12-01

This study aims to compare the marginal adaptation and sealing ability [mineral trioxide aggregate (MTA)-Fillapex, AH Plus, Endofill sealers] of root canal sealers. In the present study, the inclusion criteria include 45 single-rooted extracted mandibular premolar teeth, with single canal and complete root formation. The sectioning of the samples was done at the cementoenamel junction using a low-speed diamond disc. Step-back technique was used to prepare root canals manually. The MTA-Fillapex, AH Plus, and Endofill sealers were the three experimental sealer groups to which 45 teeth were distributed. Under scanning electron microscope (SEM), marginal gap at sealer and root dentin interface were examined at coronal and apical halves of root canal. Among the three maximum marginal adaptations were seen with AH Plus sealer (4.10 ± 0.10) which is followed by Endofill sealer (1.44 ± 0.18) and MTA-Fillapex sealer (0.80 ± 0.22). Between the coronal and apical marginal adaptation, significant statistical difference (p = 0.001) was seen in AH Plus sealer. When a Mann-Whitney U-test was done on MTA-Fillapex sealer vs AH Plus sealer and AH Plus sealer vs Endofill sealer, there was a statistically significant difference (p < 0.05) found between the above two groups at coronal and apical third. The present study proves that AH Plus sealer has a better marginal adaptation when compared with other sealers used. For sealing space of crown wall and main cone in root canal treatment, sealers play an important role. The other advantages of sealers are that they are used to fill voids and irregularities in root channel, secondary, lateral channels, and space between applied gutta-percha cones and also act as tripper during filling.

The impact of a continuing education programme on the adoption of nickel-titanium rotary instrumentation and root-filling quality amongst a group of Swedish general dental practitioners.

PubMed

Dahlström, L; Molander, A; Reit, C

2015-02-01

The aim of the study was to test the hypothesis that a further education programme relating to nickel-titanium rotary instrumentation (NTRI), with the concurrent activation of social/professional networks amongst all general dental practitioners (GDPs) in a public dental service in Sweden, would increase the adoption rate and improve root-filling quality. To activate the networks, the GDPs at the 25 clinics elected training coaches from amongst themselves. The coaches were educated by a specialist and were then free to organise and conduct the training of the local GDPs. However, collective hands-on training and discussions were mandatory. Lectures were held by an endodontist. The rate of adoption and root-filling quality was evaluated just before and 6 months after the education. Statistical tests were performed with chi-square using a 95% confidence interval. Nickel-titanium rotary instrumentation was adopted by 88%. Excellent root fillings (score 1) increased from 45% to 59% (P = 0.003). The rate of poor-quality root fillings (score 4 and score 5) was not affected. The quality ratio (score 1/score 5) increased from 5.36 (118/22) to 9.5 (133/14). Eleven dentists (17%) at nine different clinics produced 49% of the poor-quality root fillings (score 4 and score 5). Seventy-three per cent of these dentists stated that they had adopted NTRI. The introduction of NTRI will increase the adoption rate and the frequency of good-quality root fillings. However, it will not overcome the problems associated with dentists producing a low-quality level, even if a local professional network is activated. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A laboratory comparison of apical leakage between immediate versus delayed post space preparation in root canals filled with Resilon.

PubMed

Attam, K; Talwar, S

2010-09-01

To analyse ex vivo the integrity of the apical seal of Resilon root fillings following immediate post space preparation or after 1 week when leaving either 5 mm or 3 mm of remaining filling material. One hundred and fifty freshly extracted mandibular premolar teeth with single, straight root canals were used. Teeth were autoclaved and cleaned of debris and soft tissue. After decoronation at 16 mm length, the root canals were instrumented using the K3 rotary system to apical file size 45, 0.04 taper with intermittent irrigation using 1% sodium hypochlorite. The teeth were randomly divided into five groups with 30 teeth in each group. Group 1: control group in which the root canals were not filled. Group 2: the canals were filled with Resilon and a post space prepared immediately leaving 5 mm of apical filling. Group 3: the canals were filled and post space preparation delayed for 1 week leaving 5 mm of material apically. Group 4: post space preparation in the canals was initiated immediately after filling leaving 3 mm of material apically. Group 5: the root canals were filled and post space preparation was delayed for 1 week leaving 3 mm of material apically. Microleakage was evaluated using a fluid transport device. The results were analysed statistically using one-way anova followed by Bonferroni's post hoc test. P < 0.05 was considered as statistically significant. There was a highly significant difference amongst the groups (P < 0.001). The maximum mean leakage was observed in group 5 (141.63 x 10(-6) microL min(-1) cm(-1)) and the least microleakage in group 2 (99.87 x 10(-6) microL min(-1) cm(-1)). Immediate post space preparation was associated with less microleakage than delayed preparation when both 5 mm and 3 mm of apical filling remained. Leaving 5 mm of Resilon provided a significantly better seal compared to leaving 3 mm of material.

Endodontic management of maxillary first molar with seven root canals diagnosed using Cone Beam Computed Tomography scanning

PubMed Central

Raghavendra, Srinidhi Surya; Hindlekar, Ajit Narayan; Desai, Niranjan Nanasaheb; Vyavahare, Nishant Kishor; Napte, Bandu Devrao

2014-01-01

The main objective of root canal treatment is thorough cleaning and shaping of the entire pulp space and its complete filling with an inert filling material. A major cause of post-treatment disease is the inability to locate, debride or adequately fill all canals of the root canal system. The form, configuration, and number of root canals in the maxillary first molars have been discussed for more than half a century. Maxillary first molars commonly present with three roots and three canals, with a second mesiobuccal canal (MB2) also present. With the advent of improved magnification there are reports of multiple root canals in the maxillary first molars. Nonsurgical endodontic therapy of a left maxillary first molar with three roots and seven root canals was successfully performed under a dental operating microscope. The diagnosis of multiple root canals was confirmed with the help of Cone Beam Computed Tomography (CBCT) images. PMID:25565745

Efficacy of Twisted File Adaptive, Reciproc and ProTaper Universal Retreatment instruments for root-canal-filling removal: A cone-beam computed tomography study.

PubMed

Akbulut, Makbule Bilge; Akman, Melek; Terlemez, Arslan; Magat, Guldane; Sener, Sevgi; Shetty, Heeresh

2016-01-01

The aim of this study was to evaluate the efficacy of Twisted File (TF) Adaptive, Reciproc, and ProTaper Universal Retreatment (UR) System instruments for removing root-canal-filling. Sixty single rooted teeth were decoronated, instrumented and obturated. Preoperative CBCT scans were taken and the teeth were retreated with TF Adaptive, Reciproc, ProTaper UR, or hand files (n=15). Then, the teeth were rescanned, and the percentage volume of the residual root-canal-filling material was established. The total time for retreatment was recorded, and the data was statistically analyzed. The statistical ranking of the residual filling material volume was as follows: hand file=TF Adaptive>ProTaper UR=Reciproc. The ProTaper UR and Reciproc systems required shorter periods of time for retreatment. Root canal filling was more efficiently removed by using Reciproc and ProTaper UR instruments than TF Adaptive instruments and hand files. The TF Adaptive system was advantageous over hand files with regard to operating time.

Evaluation of apically extruded debris during root canal retreatment with two different rotary systems followed by a self-adjusting file.

PubMed

Cakici, Fatih; Cakici, Elif B; Küçükekenci, Funda Fundaoglu

2016-02-01

To compare the amount of apically extruded debris during root canal retreatment using ProTaper retreatment system (Dentsply Maillefer, Ballaigues, Switzerland), ProTaper retreatment system with Self-Adjusting File (SAF) system (ReDent-Nova, Ra'anana, Israel), Mtwo retreatment system (VDW, Munich, Germany), Mtwo retreatment system with SAF instruments. In total, 72 extracted human mandibular incisor teeth were used. All root canals were prepared with ProTaper universal (Dentsply Maillefer) up to F2 file and filled with gutta percha and AH plus sealer using cold lateral condensation before being assembled randomly into 4 groups (n = 18 each). Root canal filling materials were removed using the ProTaper retreatment system, the ProTaper retreatment system followed by SAF system, Mtwo retreatment system and Mtwo retreatment system followed by SAF system. Debris extruded apically during the removal of canal filling material was collected into preweighed Eppendorf tubes. The tubes were then stored in an incubator at 70°C for 5 days. The weight of the dry extruded debris was established by subtracting the preretreatment and postretreatment weight of the Eppendorf tubes for each group. The data obtained were analyzed using Kruskal-Wallis test. All retreatment techniques caused the apical extrusion of debris. There was no significant difference between the groups statistically (p>0.05). The results of this study showed that SAF system after Mtwo retreatment system and ProTaper retreatment system for improving retreatment has no significant effect on the amount of debris extruded apically.

Fracture Resistance of Endodontically Retreated Roots After Retreatment Using Self-Adjusting File, Passive Ultrasonic Irrigation, Photon-Induced Photoacoustic Streaming, or Laser.

PubMed

Kamalak, Aliye; Uzun, Ismail; Arslan, Hakan; Keleş, Ali; Doğanay, Ezgi; Keskin, Cangül; Akçay, Merve

2016-10-01

Additional cleaning techniques and devices are required to remove maximum amount of residual filling material, which might limit disinfection of root canal system during retreatment. This study aimed to compare fracture resistance of roots when self-adjusting file (SAF), photon-induced photoacoustic streaming (PIPS), passive ultrasonic irrigation (PUI), erbium-doped yttrium aluminum garnet (Er:YAG), or neodymium-doped yttrium aluminum garnet (Nd:YAG) lasers are applied following the use of retreatment files in endodontics. A total of 117 human mandibular canine teeth of similar dimensions were selected and divided into nine groups (n = 13). Aside from control, instrumented, and only-prepared groups, 91 teeth were remaining, of which 13 were assigned to the only-filling group and final 78 to retreatment, thus R-Endo file, R-Endo+SAF, R-Endo+PUI, R-Endo+Er:YAG laser, R-Endo+Nd:YAG laser, and R-Endo+PIPS. The fracture strengths of the retreatment groups were lower than control, instrumented, and only-filling groups (p < 0.05). There was no difference between the R-Endo group and additional retreatment procedure groups (p > 0.05). Further cleaning methods using SAF, PIPS, Er:YAG laser, Nd:YAG laser, or PUI did not decrease the fracture resistance when compared with the R-Endo group.

Molecular and morphological surface analysis: effect of filling pastes and cleaning agents on root dentin

PubMed Central

DAINEZI, Vanessa Benetello; IWAMOTO, Alexsandra Shizue; MARTIN, Airton Abrahão; SOARES, Luís Eduardo Silva; HOSOYA, Yumiko; PASCON, Fernanda Miori; PUPPIN-RONTANI, Regina Maria

2017-01-01

Abstract The quality of the dentin root is the most important factor for restoration resin sealing and drives the outcome of endodontic treatment. Objective This study evaluated the effect of different filling pastes and cleaning agents on the root dentin of primary teeth using Fourier-transformed Raman spectroscopy (FT-Raman), micro energy-dispersive X-ray fluorescence (µ-EDXRF) and scanning electron microscopic (SEM) analysis. Material and Methods Eighty roots of primary teeth were endodontically prepared and distributed into 4 groups and filled according to the following filling pastes: Control-no filling (CP), Calen®+zinc oxide (CZ), Calcipex II® (CII), Vitapex® (V). After seven days, filling paste groups were distributed to 4 subgroups according to cleaning agents (n=5): Control-no cleaning (C), Ethanol (E), Tergenform® (T), 35% Phosphoric acid (PA). Then, the roots were sectioned and the dentin root sections were internally evaluated by FT-Raman, µ-EDXRF and SEM. Data was submitted to two-way ANOVA and Tukey tests (α=0.05). Results Regarding filling pastes, there was no significant difference in organic content. CP provided the lowest calcium values and, calcium/phosphoric ratio (Ca/P), and the highest phosphoric values. For cleaning agents there was no difference in organic content when compared to the C; however, T showed significantly higher calcium and Ca/P than PA. All groups showed similar results for phosphorus. The dentin smear layer was present after use of the cleaning agents, except PA. Conclusion The filling pastes changed the inorganic content, however they did not change the organic content. Cleaning agents did not alter the inorganic and organic content. PA cleaned and opened dentin tubules. PMID:28198982

Comparison of retreatment ability of full-sequence reciprocating instrumentation and 360° rotary instrumentation.

PubMed

Capar, Ismail Davut; Gok, Tuba; Orhan, Ezgi

2015-12-01

The purpose of the present study was to investigate the amount of root canal filling material after root canal filling removal with 360° rotary instrumentation or reciprocating motion with the same file sequence. Root canals of the 36 mandibular premolars were shaped with ProTaper Universal instruments up to size F2 and filled with corresponding single gutta-percha cone and sealer. The teeth were assigned to two retreatment groups (n = 18): group 1 360° rotational motion and group 2 reciprocating motion of ATR Tecnika motors (1310° clockwise and 578° counterclockwise). Retreatment procedure was performed with ProTaper Universal retreatment files with a sequence of D1-3 and ProTaper Universal F3 instruments. Total time required to remove filling material were recorded. Remaining filling material was examined under stereomicroscope at ×8 magnification. The data were analysed statistically using the Mann-Whitney U test, and testing was performed at 95 % confidence level (p < 0.05). There were no significant differences between the groups (p > 0.05) in terms of remaining filling material. The total time required for retreatment was shorter in 360° rotational motion group compared to reciprocating motion group (p < 0.05). Both continuous rotation and reciprocating motion showed similar effectiveness in terms of root canal filling material removal. Using ProTaper Universal retreatment instruments with reciprocating motion of ATR motor and conventional rotary motion have similar efficacy in root canal filling removal.

Molecular and morphological surface analysis: effect of filling pastes and cleaning agents on root dentin.

PubMed

Dainezi, Vanessa Benetello; Iwamoto, Alexsandra Shizue; Martin, Airton Abrahão; Soares, Luís Eduardo Silva; Hosoya, Yumiko; Pascon, Fernanda Miori; Puppin-Rontani, Regina Maria

2017-01-01

This study evaluated the effect of different filling pastes and cleaning agents on the root dentin of primary teeth using Fourier-transformed Raman spectroscopy (FT-Raman), micro energy-dispersive X-ray fluorescence (µ-EDXRF) and scanning electron microscopic (SEM) analysis. Eighty roots of primary teeth were endodontically prepared and distributed into 4 groups and filled according to the following filling pastes: Control-no filling (CP), Calen®+zinc oxide (CZ), Calcipex II® (CII), Vitapex® (V). After seven days, filling paste groups were distributed to 4 subgroups according to cleaning agents (n=5): Control-no cleaning (C), Ethanol (E), Tergenform® (T), 35% Phosphoric acid (PA). Then, the roots were sectioned and the dentin root sections were internally evaluated by FT-Raman, µ-EDXRF and SEM. Data was submitted to two-way ANOVA and Tukey tests (α=0.05). Regarding filling pastes, there was no significant difference in organic content. CP provided the lowest calcium values and, calcium/phosphoric ratio (Ca/P), and the highest phosphoric values. For cleaning agents there was no difference in organic content when compared to the C; however, T showed significantly higher calcium and Ca/P than PA. All groups showed similar results for phosphorus. The dentin smear layer was present after use of the cleaning agents, except PA. The filling pastes changed the inorganic content, however they did not change the organic content. Cleaning agents did not alter the inorganic and organic content. PA cleaned and opened dentin tubules.

Impact of adhesive surface and volume of luting resin on fracture resistance of root filled teeth.

PubMed

Krastl, G; Gugger, J; Deyhle, H; Zitzmann, N U; Weiger, R; Müller, B

2011-05-01

To investigate the correlation between geometric parameters of severely compromised root filled (RCT) pre-molar teeth with irregular root canals and their fracture resistance. The null hypothesis tested was that the fracture resistance of root filled teeth is not influenced by: (i) the adhesive surface of the post-space preparation (A(PS) ), (ii) the coronal tooth surface (A(A) ), (iii) the amount of resin cement (V(C) ) and (iv) the Young's modulus of the specimens. A total of 48 noncarious human pre-molar teeth with irregular root canals were decoronated, root filled and adhesively restored with post-retained direct composite crowns. After thermomechanical loading (1,200,000×, 5-50° C), static load was applied until failure. The geometric parameters of the tooth were evaluated by microcomputed tomography (μCT) using impressions taken after post-space preparation. Linear regression analyses were performed to correlate the geometric parameters of the specimens with their fracture resistance. The amount of resin cement (V(C) ) comprised up to 88% of the entire post-space (mean 67%) and had no impact on the maximal load (P = 0.88). The latter was significantly influenced by post-space preparation (P = 0.003). Amongst the geometric parameters tested, the surface area in the root canal had the greatest impact on fracture resistance of root filled pre-molars restored with posts and composite crowns, whilst the fit of the post was less important. © 2011 International Endodontic Journal.

An audit on technical quality of root fillings performed by undergraduate students.

PubMed

Fong, W; Heidarifar, O; Killough, S; Lappin, M J; El Karim, I A

2018-04-01

To evaluate radiographically the technical quality of root fillings performed by undergraduate dental students and to assess whether students were exposed to an appropriate endodontic case mix during their clinical training. A retrospective audit was undertaken evaluating the clinical records of patients who underwent endodontic procedures during the period from September 2015 to June 2016 in the Dental School at Queen's University Belfast, UK. Two final-year dental students were trained and calibrated to evaluate postoperative intra-oral periapical radiographs of completed root canal treatments using specific assessment criteria. Data were presented as frequencies, percentage and mean ± standard deviation (SD). Comparisons of treatment outcomes between groups (posterior and anterior teeth) were calculated using Fisher's exact test, and the level of significance was set at P < 0.05. Intra- and interexaminer reproducibility was assessed by Kappa statistics. A total of 222 teeth and 381 canals were assessed, and of those, 253 (66%) of the root fillings were found to be acceptable in all the assessment parameters, namely taper, length and lateral adaptation of the root filling. Subanalysis of individual root filling parameters revealed that 372 canals (97%) exhibited good taper, and 275 canals (72%) were considered to be of an appropriate length, with 89 canals (23%) found to be underfilled and 17 canals (5%) overfilled. Overall 346 (91%) of canals had good lateral condensation. Students treated both single and multirooted teeth, and there was no significant association between tooth type and the quality of root filling provided (P > 0.05). In the majority of the teeth treated by undergraduate students at Queen's University Belfast, the technical quality of the root filling was acceptable and students were exposed to an appropriate case mix for endodontic training. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Layered Plant-Growth Media for Optimizing Gaseous, Liquid and Nutrient Requirements: Modeling, Design and Monitoring

NASA Astrophysics Data System (ADS)

Heinse, R.; Jones, S. B.; Bingham, G.; Bugbee, B.

2006-12-01

Rigorous management of restricted root zones utilizing coarse-textured porous media greatly benefits from optimizing the gas-water balance within plant-growth media. Geophysical techniques can help to quantify root- zone parameters like water content, air-filled porosity, temperature and nutrient concentration to better address the root systems performance. The efficiency of plant growth amid high root densities and limited volumes is critically linked to maintaining a favorable water content/air-filled porosity balance while considering adequate fluxes to replenish water at decreasing hydraulic conductivities during uptake. Volumes adjacent to roots also need to be optimized to provide adequate nutrients throughout the plant's life cycle while avoiding excessive salt concentrations. Our objectives were to (1) design and model an optimized root zone system using optimized porous media layers, (2) verify our design by monitoring the water content distribution and tracking nutrient release and transport, and (3) mimic water and nutrient uptake using plants or wicks to draw water from the root system. We developed a unique root-zone system using layered Ottawa sands promoting vertically uniform water contents and air-filled porosities. Watering was achieved by maintaining a shallow saturated layer at the bottom of the column and allowing capillarity to draw water upward, where coarser particle sizes formed the bottom layers with finer particles sizes forming the layers above. The depth of each layer was designed to optimize water content based on measurements and modeling of the wetting water retention curves. Layer boundaries were chosen to retain saturation between 50 and 85 percent. The saturation distribution was verified by dual-probe heat-pulse water-content sensors. The nutrient experiment involved embedding slow release fertilizer in the porous media in order to detect variations in electrical resistivity versus time during the release, diffusion and uptake of nutrients. The experiment required a specific geometry for the acquisition of ERT data using the heat-pulse water-content sensor's steel needles as electrodes. ERT data were analyzed using the sensed water contents and deriving pore-water resistivities using Archie's law. This design should provide a more optimal root-zone environment by maintaining a more uniform water content and on-demand supply of water than designs with one particle size at all column heights. The monitoring capability offers an effective means to describe the relationship between root-system performance and plant growth.

[The development and in vitro experiment study of a bio-type root canal filling sealer using calcium phosphate cement].

PubMed

Chen, Zuo-liang; Wei, Wei; Feng, Zhu-de; Liu, Xue-qing; Chen, Xiao-ling; Huang, Wen-xia

2007-10-01

The purpose of this study is to develop a novel root canal filling sealers based on calcium phosphate cement (CPC), and to evaluate its physical-chemical properties and in vitro antibacterial activity on the predominant bacteria infecting root canal. The fluidity and the setting time of the sealer were tested according to ISO 6876:2001(E) standards. The crystal size of the final product was determined. Its opacification with different composition were measured. The in vitro antibacterial property of the sealer was tested according to the Antimicrobial Susceptibility Testing of Anaerobes recommended by National Committee for Clinical Laboratory Standards (NCCLs). The involved bacteria included Actinomyces naeslundii(A. naeslundii), Peptostreptococcus anaerobius (P. anaerobius), Porphyromonas gingivalis (P. gingivalis), Porphyromonas endodpntalis (P. endodpntalis) and Fusobacterium nucleatum (F. nucleatum). Twenty single-rooted human extracted teeth were selected to evaluate the sealing ability using dye microleakage technology. Dye penetration was measured and the results were statistically analyzed using SPSS12.0 software package. The new root canal filling sealer was primarily composed of hydroxyapatite in 279 nm after setting. Its liquidity was suitable, the operating time was over 30 minutes, and the controlled setting time was (1.0+/-0.5) hours. The opacification was acceptable. MIC

Rotary endodontics in primary teeth – A review

PubMed Central

George, Sageena; Anandaraj, S.; Issac, Jyoti S.; John, Sheen A.; Harris, Anoop

2015-01-01

Endodontic treatment in primary teeth can be challenging and time consuming, especially during canal preparation, which is considered one of the most important steps in root canal therapy. The conventional instrumentation technique for primary teeth remains the “gold-standard” over hand instrumentation, which makes procedures much more time consuming and adversely affects both clinicians and patients. Recently nickel–titanium (Ni–Ti) rotary files have been developed for use in pediatric endodontics. Using rotary instruments for primary tooth pulpectomies is cost effective and results in fills that are consistently uniform and predictable. This article reviews the use of nickel–titanium rotary files as root canal instrumentation in primary teeth. The pulpectomy technique is described here according to different authors and the advantages and disadvantages of using rotary files are discussed. PMID:26792964

Rotary endodontics in primary teeth - A review.

PubMed

George, Sageena; Anandaraj, S; Issac, Jyoti S; John, Sheen A; Harris, Anoop

2016-01-01

Endodontic treatment in primary teeth can be challenging and time consuming, especially during canal preparation, which is considered one of the most important steps in root canal therapy. The conventional instrumentation technique for primary teeth remains the "gold-standard" over hand instrumentation, which makes procedures much more time consuming and adversely affects both clinicians and patients. Recently nickel-titanium (Ni-Ti) rotary files have been developed for use in pediatric endodontics. Using rotary instruments for primary tooth pulpectomies is cost effective and results in fills that are consistently uniform and predictable. This article reviews the use of nickel-titanium rotary files as root canal instrumentation in primary teeth. The pulpectomy technique is described here according to different authors and the advantages and disadvantages of using rotary files are discussed.

External apical root resorption in maxillary root-filled incisors after orthodontic treatment: A split-mouth design study

PubMed Central

Amarilla, Almudena; Espinar-Escalona, Eduardo; Castellanos-Cosano, Lizett; Martín-González, Jenifer; Sánchez-Domínguez, Benito; López-Frías, Francisco J.

2012-01-01

Introduction: The purpose of this study was to compare, in a split mouth design, the external apical root resorption (EARR) associated with orthodontic treatment in root-filled maxillary incisors and their contralateral teeth with vital pulps. Methodology: The study sample consisted of 38 patients (14 males and 24 females), who had one root-filled incisor before completion of multiband/bracket orthodontic therapy for at least 1 year. For each patient, digital panoramic radiographs taken before and after orthodontic treatment were used to determine the root resortion and the proportion of external root resorption (PRR), defined as the ratio between the root resorption in the endodontically treated incisor and that in its contralateral incisor with a vital pulp. The student’s t-test, chi-square test and logistic regression analysis were used to determine statistical significance. Results: There was no statistically significant difference (p > 0.05) between EARR in vital teeth (1.1 ± 1.0 mm) and endodontically treated incisors (1.1 ± 0.8 mm). Twenty-six patients (68.4%) showed greater resorption of the endodontically treated incisor than its homolog vital tooth (p > 0.05). The mean and standard deviation of PPR were 1.0 ± 0.2. Multivariate logistic regression suggested that PRR does not correlate with any of the variables analyzed. Conclusions: There was no significant difference in the amount or severity of external root resorption during orthodontic movement between root-filled incisors and their contralateral teeth with vital pulps. Key words:Endodontics, orthodontics, root canal treatment, root resorption. PMID:22143731

Extension and Density of Root Fillings and Post-operative Apical Radiolucencies in the Veterans Affairs Dental Longitudinal Study

PubMed Central

Zhong, Yan; Chasen, Joel; Yamanaka, Ryan; Garcia, Raul; Kaye, Elizabeth Krall; Kaufman, Jay S; Cai, Jianwen; Wilcosky, Tim; Trope, Martin; Caplan, Daniel J

2008-01-01

We evaluated the association between radiographically-assessed extension and density of root canal fillings and post-operative apical radiolucencies (AR) using data from 288 participants in the Veterans Affairs Dental Longitudinal Study. Study subjects were not VA patients; all received their medical and dental care in the private sector. Generalized Estimating Equations were used to account for multiple teeth within subjects and to control for covariates of interest. Defective root filling density was associated with increased odds of post-operative AR among teeth with no pre-operative AR (Odds Ratio=3.0, 95%CI=1.3–7.1), though pre-operative AR was the strongest risk factor for post-operative AR (Odds Ratio=29.2, 95%CI=13.6–63.0 among teeth with ideal density). Compared to well-extended root fillings, neither over- nor under-extended root fillings separately were related to post-operative AR, but when those two categories were collapsed into one “poorly-extended” category, poor extension was related to post-operative AR (Odds Ratio=1.8, 95%CI=1.1–3.2). PMID:18570982

External apical root resorption in maxillary root-filled incisors after orthodontic treatment: a split-mouth design study.

PubMed

Llamas-Carreras, José María; Amarilla, Almudena; Espinar-Escalona, Eduardo; Castellanos-Cosano, Lizett; Martín-González, Jenifer; Sánchez-Domínguez, Benito; López-Frías, Francisco Javier

2012-05-01

The purpose of this study was to compare, in a split mouth design, the external apical root resorption (EARR) associated with orthodontic treatment in root-filled maxillary incisors and their contralateral teeth with vital pulps. The study sample consisted of 38 patients (14 males and 24 females), who had one root-filled incisor before completion of multiband/bracket orthodontic therapy for at least 1 year. For each patient, digital panoramic radiographs taken before and after orthodontic treatment were used to determine the root resortion and the proportion of external root resorption (PRR), defined as the ratio between the root resorption in the endodontically treated incisor and that in its contralateral incisor with a vital pulp. The student's t-test, chi-square test and logistic regression analysis were used to determine statistical significance. There was no statistically significant difference (p > 0.05) between EARR in vital teeth (1.1 ± 1.0 mm) and endodontically treated incisors (1.1 ± 0.8 mm). Twenty-six patients (68.4%) showed greater resorption of the endodontically treated incisor than its homolog vital tooth (p > 0.05). The mean and standard deviation of PPR were 1.0 ± 0.2. Multivariate logistic regression suggested that PRR does not correlate with any of the variables analyzed. There was no significant difference in the amount or severity of external root resorption during orthodontic movement between root-filled incisors and their contralateral teeth with vital pulps.

A titration model for evaluating calcium hydroxide removal techniques.

PubMed

Phillips, Mark; McClanahan, Scott; Bowles, Walter

2015-01-01

Calcium hydroxide (Ca(OH)2) has been used in endodontics as an intracanal medicament due to its antimicrobial effects and its ability to inactivate bacterial endotoxin. The inability to totally remove this intracanal medicament from the root canal system, however, may interfere with the setting of eugenol-based sealers or inhibit bonding of resin to dentin, thus presenting clinical challenges with endodontic treatment. This study used a chemical titration method to measure residual Ca(OH)2 left after different endodontic irrigation methods. Eighty-six human canine roots were prepared for obturation. Thirty teeth were filled with known but different amounts of Ca(OH)2 for 7 days, which were dissolved out and titrated to quantitate the residual Ca(OH)2 recovered from each root to produce a standard curve. Forty-eight of the remaining teeth were filled with equal amounts of Ca(OH)2 followed by gross Ca(OH)2 removal using hand files and randomized treatment of either: 1) Syringe irrigation; 2) Syringe irrigation with use of an apical file; 3) Syringe irrigation with added 30 s of passive ultrasonic irrigation (PUI), or 4) Syringe irrigation with apical file and PUI (n=12/group). Residual Ca(OH)2 was dissolved with glycerin and titrated to measure residual Ca(OH)2 left in the root. No method completely removed all residual Ca(OH)2. The addition of 30 s PUI with or without apical file use removed Ca(OH)2 significantly better than irrigation alone. This technique allowed quantification of residual Ca(OH)2. The use of PUI (with or without apical file) resulted in significantly lower Ca(OH)2 residue compared to irrigation alone.

Protecting tree roots and subterranean infrastructure in urban areas by developing self-compacting flowable fills with root growth impeding properties

NASA Astrophysics Data System (ADS)

Felde, Vincent; Simon, Jana; Kimm-Friedenberg, Stefan; Peth, Stephan; Middendorf, Bernhard

2015-04-01

In urban areas, the installation of cables and disposal lines is still done by open building method. Here, a ditch is being excavated, pipes and lines are laid and subsequently it is filled with and covered by bulk material (e.g. sand or gravel), which is then compacted. Due to the often times limited space that the roots have in the ground and the better supply of water and oxygen in the poorly compacted bulk material, these refilled ditches are areas of preferential root growth of urban trees. The entangling of the pipes and supply lines by these roots leads to severe damage of the tree when maintenance work on the lines is carried out and roots have to be cut. In order to reduce this competition between urban trees and urban subterranean infrastructure, the development of a self-compacting flowable fill with root growth resistance is mandatory. Physico-chemical properties, such as a very high pH-value and a low cation-exchange-capacity, a low root-penetrability, a high packing density and a low porosity, with a poorly connected pore system that impedes gas and water exchange are the characteristic aspects of this flowable fills that could help avoid undesired root penetration into supply lines. The flowable fills are supposed to sheath pipes and lines void-free and without any tension, in order to restrain the root growth in these areas. Trees are of crucial importance for urban ecosystems and are comprising 3% of the total stock of trees in the Federal Republic of Germany, which is why it is fundamental to conserve them. This work therefore targets not only at enabling a balanced coexistence of urban trees and subterranean infrastructure, but also at avoiding costly re-opening of ditches, tree harming cutting of roots and time consuming maintenance work. Further positive side effects are reduced costs for network providers and local municipalities, as well as reduced noise and dust emissions for passersby and local residents. To guarantee the root growth restricting properties, the self-compacting fill has to have less porosity than the adjacent soil (40 - 60%). Theoretically a porosity of 30% is possible with a homogeneous compaction of sand. In urban areas, however, because of the limited spaces and crossing pipes, a mechanical and homogenous compacting is often impossible. Porosities of 60 to 70% are the result. Self-compacting flowable fills have a porosity of about 40% while the first optimized materials can even have a porosity of 28%. We present the first results of the hydro-mechanical properties of the different materials under development that highlight the influence of the mixture of the fills (i.e. maximal grain size) on the root growth impeding properties, while still ensuring mechanical workability of the material (in spite of the low porosity, strengths less than 0.8 N mm-² must be ensured at all times).

Impact of root canal preparation size and taper on coronal-apical micro-leakage using glucose penetration method

PubMed Central

Tabrizizadeh, Mehdi; Hekmati-Moghadam, Seyed-Hossein; Hakimian, Roqayeh

2014-01-01

Objectives: The purpose of this in vitro study was to assess the effect of root canal preparation size and taper on the amounts of glucose penetration. Material and Methods: For conducting this experimental study, eighty mandibular premolars with single straight canals were divided randomly into 2 experimental groups of 30 samples each and 2 control groups. Using K-files and the balance force technique, canals in group 1 were prepared apically to size 25 and coronally to size 2 Peesoreamer. Group 2 were instrumented apically and coronally to size 40 and size 6 Peesoreamer, respectively. Rotary instrumentation was accomplished in group 1; using size 25 and .04 tapered and in group 2, size 35 and .06 tapered Flex Master files. Canals were then obturated by lateral compaction of cold gutta-percha. Glucose penetration through root canal fillings was measured at 1, 8, 15, 22 and 30 days. Data were recorded as mmol/L and statistically analyzed with Mann-Whitney U test (P value=. 05). Results: In comparison to group 1, group 2 showed significant glucose leakage during the experimental period (P value < .0001). Also, in each experimental group, the amount of micro-leakage was significantly increased at the end of the study. Conclusions: Under the condition of this study, the amounts of micro-leakage through root canal fillings are directly related to the size and taper of root canal preparation and reducing the preparation size may lead to less micro-leakage. Key words:Dental leakage, root canal preparation, endodontics. PMID:25593654

Effect of two storage solutions on surface topography of two root-end fillings.

PubMed

Asgary, Saeed; Eghbal, Mohammad Jafar; Parirokh, Masoud; Ghoddusi, Jamileh

2009-12-01

The effect of different storage solutions on surface topography of mineral trioxide aggregate (MTA) and new experimental cement (NEC) as root-end fillings was investigated. Twenty-four single-rooted teeth were cleaned, shaped and obturated in a same manner. After root-end resection, 3-mm deep root-end cavities were ultrasonically prepared. Samples were randomly divided into four test groups (A1-A2-B1-B2, n = 6). Root-end cavities in groups A and B were filled with MTA and NEC, respectively, and were then stored in 100% humidity for 24 h. The samples of groups 1 and 2 were, respectively, immersed in normal saline (NS) and phosphate buffer saline solutions for 1 week. The samples were imaged under stereomicroscope before and after immersion and were then investigated and analysed by scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDXA). Results showed significant difference among studied groups. Surface topography of all samples was altered by crystal formation and precipitation on root-end fillings except for group A1 (MTA-NS). SEM and EDXA results showed that the composition and structure of precipitated crystals were comparable with that of standard hydroxyapatite. It was concluded that biocompatibility, sealing ability, and cementogenic activity of MTA and probably NEC may be attributed to this fundamental bioactive reaction.

Effect of retained fractured instruments on tooth resistance to vertical fracture with or without attempt at removal.

PubMed

Madarati, A A; Qualtrough, A J E; Watts, D C

2010-11-01

To investigate the effect of retained fractured endodontic instruments on root strength and to evaluate the effectiveness of several root filling materials in reinforcing roots that had undergone unsuccessful attempt at removal of fractured instruments. Seventy five mandibular premolar roots were divided into five groups. In group A (control), canals were prepared to a size F5-ProTaper instrument and filled with gutta-percha and TubliSeal sealer fragments. In the experimental groups (B, C, D and E), 4 mm of F5-ProTaper instruments were fractured in the apical one-third of the canal and then treated as follows: in group B, the fragments were left in situ without attempt at removal, and canals were filled with gutta-percha and TubliSeal sealer (GP No Removal). In groups C, D and E, an attempt at removal of the fragment was simulated by preparing a staging platform coronal to the fragment using modified Gates Glidden burs (No 2-5). Canals in group C were filled with gutta-percha and TubliSeal sealer (GP Removal), group D filled with Resilon (Resilon Removal) and group E with mineral trioxide aggregate (MTA Removal). Roots then underwent vertical fracture. Data were analysed using the one-way anova at P<0.05. Roots in the GP Removal group had significantly lower values for mean force for fracture (404.9 N). There was no significant difference between the control group and GP No Removal (765.2 and 707.8, respectively). Resilon Removal and MTA Removal groups (577.3 and 566.6 N) were not significantly different from the GP No Removal group. Leaving fractured instruments in the apical one-third of the canal does not appear to affect the resistance of the root to vertical fracture; Resilon and MTA appear to compensate for root dentine loss that occurred as a consequence of attempts at retrieval of fractured instruments when used as canal filling materials. © 2010 International Endodontic Journal.

Technical quality of root canal treatment performed by undergraduate students using hand instrumentation: a meta-analysis.

PubMed

Ribeiro, D M; Réus, J C; Felippe, W T; Pacheco-Pereira, C; Dutra, K L; Santos, J N; Porporatti, A L; De Luca Canto, G

2018-03-01

The technical quality of root canal treatment (RCT) may impact on the outcome. The quality of education received during undergraduate school may be linked to the quality of treatment provided in general dental practice. In this context, the aim of this systematic review was to answer the following focused questions: (i) What is the frequency of acceptable technical quality of root fillings, assessed radiographically, performed by undergraduate students? (ii) What are the most common errors assessed radiographically and reported in these treatments? For this purpose, articles that evaluated the quality of root fillings performed by undergraduate students were selected. Data were collected based on predetermined criteria. The key features from the included studies were extracted. GRADE-tool assessed the quality of the evidence. MAStARI evaluated the methodological quality, and a meta-analysis on all studies was conducted. At the end of the screening, 24 articles were identified. Overall frequency of acceptable technical quality of root fillings was 48%. From this total, 52% related to anterior teeth, 49% to premolars and 26% to molars. The main procedural errors reported were ledge formation, furcation perforation, apical transportation and apical perforation. The heterogeneity amongst the studies was high (84-99%). Five studies had a high risk of bias, eight had a moderate risk, and 11 had low risk. The overall quality of evidence identified was very low. The conclusion was that technical quality of root fillings performed by undergraduate students is low, which may reveal that endodontic education has limited achievement at undergraduate level. A plan to improve the quality of root fillings, and by extrapolation the overall quality of root canal treatment, should be discussed by the staff responsible for endodontic education and training. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

An experimental technique to repair cracked teeth using calcium phosphate, melted by a laser beam: an in vitro evaluation.

PubMed

Levy, G C; Koubi, G F

1993-11-01

Using a neodymium: yttrium-aluminum-garnet laser beam to seal vertical root fracture lines with tricalcium phosphate paste represents an alternative treatment for cracked teeth with noted clinical results. This article describes a study of the permeability of molten crystals of hydroxyapatite in the dentin of a cracked root after crack lines have been filled with a preparation of tricalcium phosphate melted by a neodymium: yttrium-aluminum-garnet laser beam. The morphology of the sealed cracks was analyzed under a scanning electron microscope that showed a deep fusion of tricalcium phosphate along crack lines.

Intraorifice sealing ability of different materials in endodontically treated teeth: An in vitro study.

PubMed

Parekh, Bandish; Irani, Rukshin S; Sathe, Sucheta; Hegde, Vivek

2014-05-01

Microbial contamination of the pulp space is one of the major factors associated with endodontic failure. Thus, in addition to a three dimentional apical filling a coronal seal for root canal fillings has been recommended. The present study was conducted to evaluate and compare the intra-orifice sealing ability of three experimental materials after obturation of the root canal system. Fourty single rooted mandibular premolars were decoronated, cleaned, shaped and obturated. Gutta-percha was removed to the depth of 3.5 mm from the orifice with a heated plugger. Ten specimens each were sealed with Light Cure Glass Ionomer Cement (LCGIC), Flowable Composite (Tetric N-Flow), and Light Cure Glass Ionomer Cement with Flowable Composite in Sandwich Technique along with a positive control respectively and roots submerged in Rhodamine-B dye in vacuum for one week. Specimens were longitudinally sectioned and leakage measured using a 10X stereomicroscope and graded for depth of leakage. According to the results of the present study LC GIC + Tetric N Flow demonstrated significantly better seal (P < 0.01) than LC GIC. However there was no statistically significant difference in leakage (P > 0.01) between Tetric N-Flow and LCGIC+Tetric N-Flow groups. In the current study LCGIC+Tetric N-Flow was found to be superior over other experimental materials as intra-orifice barriers.

Cleaning of Root Canal System by Different Irrigation Methods.

PubMed

Tanomaru-Filho, Mário; Miano, Lucas Martinati; Chávez-Andrade, Gisselle Moraima; Torres, Fernanda Ferrari Esteves; Leonardo, Renato de Toledo; Guerreiro-Tanomaru, Juliane Maria

2015-11-01

The aim of this study was to compare the cleaning of main and lateral canals using the irrigation methods: negative pressure irrigation (EndoVac system), passive ultrasonic irrigation (PUI) and manual irrigation (MI). Resin teeth were used. After root canal preparation, four lateral canals were made at 2 and 7 mm from the apex. Root canals were filled with contrast solution and radiographed pre- and post-irrigation using digital radiographic system [radiovisiography (RVG)]. The irrigation protocols were: MI1-manual irrigation [22 G needle at 5 mm short of working length-WL]; MI2-manual irrigation (30G needle at 2 mm short of WL); PUI; EV1-EndoVac (microcannula at 1 mm short of WL); EV2-Endovac (microcannula at 3 mm short of WL). The obtained images, initial (filled with contrast solution) and final (after irrigation) were analyzed by using image tool 3.0 software. Statistical analysis was performed by analysis of variance (ANOVA) and Tukey tests (5% significance level). EV1 and EV2, followed by PUI showed better cleaning capacity than manual irrigation (MI1 and MI2) (p < 0.05). Negative pressure irrigation and PUI promoted better cleaning of main and simulated lateral canals. Conventional manual irrigation technique may promote less root canal cleaning in the apical third. For this reason, the search for other irrigation protocols is important, and EndoVac and PUI are alternatives to contribute to irrigation effectiveness.

The Tubular Penetration Depth and Adaption of Four Sealers: A Scanning Electron Microscopic Study

PubMed Central

Chen, Huan; Zhao, Xinyuan; Qiu, Yu; Xu, Dengyou

2017-01-01

Background. The tubular penetration and adaptation of the sealer are important factors for successful root canal filling. The aim of this study was to evaluate the tubular penetration depth of four different sealers in the coronal, middle, and apical third of root canals as well as the adaptation of these sealers to root canal walls. Materials and Methods. 50 single-rooted teeth were prepared in this study. Forty-eight of them were filled with different sealers (Cortisomol, iRoot SP, AH-Plus, and RealSeal SE) and respective core filling materials. Then the specimens were sectioned and scanning electron microscopy was employed to assess the tubular penetration and adaptation of the sealers. Results. Our results demonstrated that the maximum penetration was exhibited by RealSeal SE, followed by AH-Plus, iRoot SP, and Cortisomol. As regards the adaptation property to root canal walls, AH-Plus has best adaptation capacity followed by iRoot SP, RealSeal SE, and Cortisomol. Conclusion. The tubular penetration and adaptation vary with the different sealers investigated. RealSeal SE showed the most optimal tubular penetration, whereas AH-Plus presented the best adaptation to the root canal walls. PMID:29479539

SEM and microCT validation for en face OCT imagistic evaluation of endodontically treated human teeth

NASA Astrophysics Data System (ADS)

Negrutiu, Meda L.; Nica, Luminita; Sinescu, Cosmin; Topala, Florin; Ionita, Ciprian; Bradu, Adrian; Petrescu, Emanuela L.; Pop, Daniela M.; Rominu, Mihai; Podoleanu, Adrian Gh.

2011-03-01

Successful root canal treatment is based on diagnosis, treatment planning, knowledge of tooth anatomy, endodontic access cavity design, controlling the infection by thorough cleaning and shaping, methods and materials used in root canal obturation. An endodontic obturation must be a complete, three-dimensional filling of the root canal system, as close as possible to cemento-dentinal junction, without massive overfilling or underfilling. There are several known methods which are used to assess the quality of the endodontic sealing, but most are invasive. These lead to the destruction of the samples and often no conclusion could be drawn in respect to the existence of any microleakage in the investigated areas of interest. Using an time domain en-face OCT system, we have recently demonstrated real time thorough evaluation of quality of root canal fillings. The purpose of this in vitro study was to validate the en face OCT imagistic evaluation of endodontically treated human teeth by using scanning electron microscopy (SEM) and microcomputer tomography (μCT). SEM investigations evidenced the nonlinear aspect of the interface between the endodontic filling material and the root canal walls and materials defects in some samples. The results obtained by μCT revealed also some defects inside the root-canal filling and at the interfaces between the material and the root canal walls. The advantages of the OCT method consist in non-invasiveness and high resolution. In addition, en face OCT investigations permit visualization of the more complex stratified structure at the interface between the filling material and the dental hard tissue.

Revitalization of open apex teeth with apical periodontitis using a collagen-hydroxyapatite scaffold.

PubMed

Nevins, Alan J; Cymerman, Jerome J

2015-06-01

An enhanced revision of the revitalization endodontic technique for immature teeth with apical periodontitis has been described. It includes the addition of collagen-hydroxyapatite scaffold to the currently practiced revascularization technique. Four cases treated in series are presented in this report, 1 case involving 2 teeth. Periapical diagnoses of immature teeth included "asymptomatic apical periodontitis," "symptomatic apical periodontitis," and "acute apical abscess." Additionally, 1 fully developed tooth that had undergone root canal treatment that failed had a periapical diagnosis of acute apical abscess. An established revascularization protocol was used for all teeth. In addition to stimulating blood clots, all teeth were filled with collagen-hydroxyapatite scaffolds. Periapical radiolucencies healed in all teeth, and diffuse radiopacity developed within the coronal portions of canal spaces. Root development with root lengthening occurred in the immature nonvital maxillary premolar that had not undergone prior treatment. The technique of adding a collagen-hydroxyapatite scaffold to the existing revitalization protocol has been described in which substantial hard tissue repair has occurred. This may leave teeth more fully developed and less likely to fracture. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

An evaluation of .06 tapered gutta-percha cones for filling of .06 taper prepared curved root canals.

PubMed

Gordon, M P J; Love, R M; Chandler, N P

2005-02-01

To compare the area occupied by gutta-percha, sealer, or void in standardized .06 tapered prepared simulated curved canals and in mesio-buccal canals of extracted maxillary first molars filled with a single .06 gutta-percha point and sealer or lateral condensation of multiple .02 gutta-percha points and sealer. Simulated canals in resin blocks with either a 30 degrees curve and radius of 10.5 mm (n = 20) or a 58 degrees curve and 4.7 mm radius (n = 20) and curved mesio-buccal canals of extracted maxillary first molars (n = 20) were prepared using .06 ProFiles in a variable tip crown-down sequence to an apical size 35 at 0.5 mm from the canal terminus or apical foramen. Ten 30 degrees and 58 degrees curved resin canals and 10 canals in the extracted teeth group were obturated with .02 taper gutta-percha cones and AH 26 sealer using lateral condensation. The time required to obturate was recorded. The remaining canals were obturated with a single .06 taper gutta-percha cone and AH 26 sealer. Excess gutta-percha was removed from the specimens using heat and the warm mass vertically condensed. Horizontal sections were cut at 0.5, 1.5, 2.5, 4.5, 7.5 and 11.5 mm from the canal terminus or apical foramen. Colour photographs were taken using an Olympus 35 mm camera attached to a stereomicroscope set at x40 magnification, and then digitized using a flatbed scanner. The cross-sectional area of the canal contents was analysed using Adobe PhotoShop. The percentage of gutta-percha, sealer or voids to the total root canal area were derived and data analysed using unpaired Student's t-test and the Mann-Whitney U-test. In the 30 degrees curved canals the levels had between 94 and 100% of the area filled with gutta-percha with no significant difference (P > 0.05) between the lateral condensation and single cone techniques. In the 58 degrees curved canals the levels had 92-99% of the area filled with gutta-percha, with the single cone technique having significantly (P < 0.05) more gutta-percha fill at the 2.5 mm level only. In the mesio-buccal canals of the teeth the levels had between 72 and 96% of the area filled with gutta-percha with no significant difference (P > 0.05) between the lateral condensation and single cone technique. The time for obturation was significantly (P < 0.05) greater for lateral condensation compared with the single cone technique in all groups. The .06 taper single cone technique was comparable with lateral condensation in the amount of gutta-percha occupying a prepared .06 tapered canal. The .06 single cone technique was faster than lateral condensation.

Comparison of efficiency of the retreatment procedure between Wave One Gold and Wave One systems by Micro-CT and confocal microscopy: an in vitro study.

PubMed

Canali, Lyz Cristina Furquim; Duque, Jussaro Alves; Vivan, Rodrigo Ricci; Bramante, Clovis Monteiro; Só, Marcus Vinícius Reis; Duarte, Marco Antonio Hungaro

2018-04-19

To compare, by Micro-CT and confocal laser scanning microscopy (CLSM), the ability of the Wave One Gold and Wave One systems to remove filling material from mesial canals of mandibular molars, effective time spent; quantity of extruded material, and percentage of sealer in the dentinal tubules after retreatment and re-obturation procedures. Ten first mandibular molars (n = 20 mesial canals) were prepared and filled with gutta-percha and Endofill sealer mixed with Rhodamine B dye using the single cone technique. After 7 days, the canals were scanned using a high-definition micro-computer tomography with 19-mm voxel size and divided into two groups (n = 10) according to the system used in retreatment: group 1, Wave One (WO), and group 2, Wave One Gold (WG). After removing filling material with the primary file of each system, the WO 40/.08 and WG 35/.06 files were used. After using each file, a new scanning was performed and the residual filling material and extruded filling material were measured. The effective time spent to remove the canal filling was measured after each instrument. After retreatment, the teeth were re-obturated with gutta-percha and AH Plus sealer mixed with fluorescein dye using the single-cone technique. The roots were sectioned at 2, 4 and 6 mm and analysed by CLSM to measure the percentage of remaining sealer and the sealer of the new root canal filling. The data were statistically compared (P < 0.05). Both systems presented a similar volume of filling material remaining in the canals after the use of the two instruments, similar residual and new material in the dentinal tubules, and similar extrusion of material (P > 0.05). When using WO 25, the operator spent significantly less effective time than when using WG 25 (P < 0.05); however, use of WG 35 and WO 40 required a similar time to remove filling material from the canals (P > 0.05). Neither of the two systems removed all the filling material. The WG system presented similar ability in removing filling and extruded material in comparison with WO system. The effective time spent was shorter for WO 25 than for WG 25. Wave One Gold can be an alternative to perform retreatment considering that in comparison with Wave One, there was no difference in filling material removal capacity and extruded materials. There was only difference in the effective time spent, in which the operator spent more time with WG 25 than with WO 25.

Microflora of root filled teeth with apical periodontitis in Latvian patients.

PubMed

Mindere, Anda; Kundzina, Rita; Nikolajeva, Vizma; Eze, Daina; Petrina, Zaiga

2010-01-01

The aim of the present study was to investigate the microbial flora of root filled teeth with apical periodontitis and to determine the prevalence of β-lactamase producing strains in isolated bacteria in Latvian patients. 33 root filled teeth with asymptomatic persisting periapical lesions were selected for the present study. During nonsurgical endodontic retreatment, the root filling material was removed and canals were sampled. Determination of microbial species was based on series of biochemical tests using identification kits. All strains of bacteria were tested for β-lactamase production by using chromogenic nitrocefin-impregnated slides. Bacteria were found in 32 (97%) of initial specimens from the teeth. The number of isolated microbial strains in the specimens ranged from one to six (mean 2.7). 79% of the isolated microbial species were Gram-positive bacteria. The most common isolates were Streptococcus (27%), Actinomyces (27%), Staphylococcus (18%), Enterococcus (18%) and Lactobacillus (18%) spp. Yeasts were found as four isolates in 3 cases (9%). β-lactamase-producing bacterial strains were detected in 12 specimens, 36% of the patients. The most common enzyme-producing bacteria belonged to Actinomyces and Staphylococcus spp. The microbial flora in previously treated root canals with apical periodontitis is limited to a small number of predominantly Gram-positive microbial species. The most common isolates are Streptococcus, Actinomyces, Staphylococcus, Enterococcus and Lactobacillus spp. A moderately high prevalence of β-lactamase producing bacterial strains was detected in patients with root filled teeth with apical periodontitis.

Sealing ability of white and gray mineral trioxide aggregate mixed with distilled water and 0.12% chlorhexidine gluconate when used as root-end filling materials.

PubMed

Shahi, Shahriar; Rahimi, Saeed; Yavari, Hamid Reza; Shakouie, Sahar; Nezafati, Saeed; Abdolrahimi, Majid

2007-12-01

This in vitro study used dye penetration to compare the sealing ability of white and gray mineral trioxide aggregate mixed with distilled water and 0.12% chlorhexidine gluconate when used as root-end filling materials. Ninety-six single-rooted human teeth were cleaned, shaped, and obturated with gutta-percha and AH26 root canal sealer. The apical 3 mm of each root was resected, and 3-mm deep root-end cavity preparations were made. The teeth were randomly divided into 4 experimental groups, each containing 20 teeth, and 2 negative and positive control groups, each containing 8 teeth. Root-end cavities in the experimental groups were filled with the experimental materials. After decoronation of the teeth and application of nail polish, the teeth were exposed to India ink for 72 hours and longitudinally sectioned, and the extent of dye penetration was measured with a stereomicroscope. Statistical analysis showed that there were no significant differences among the 4 experimental groups.

Contamination of tooth-colored mineral trioxide aggregate used as a root-end filling material: a bacterial leakage study.

PubMed

Montellano, Angela M; Schwartz, Scott A; Beeson, Thomas J

2006-05-01

This experiment investigated the ability of tooth-colored mineral trioxide aggregate (MTA) to maintain an apical seal in the presence of bacteria when contaminated with blood, saline or saliva. Ninety extracted human teeth with single canals were randomly placed into six groups of 15. Canals were prepared to size 50. The apical 3 mm of each root was removed and 3 mm root-end preparations were made with a #329 bur. Root-end preparations in groups 1 through 3 were filled with MTA after contamination with blood, saline, or saliva, respectively. In group 4, uncontaminated root-end preparations were filled with MTA. Groups 5 and 6 served as negative and positive controls. A tube/tooth assembly was utilized to suspend each root end in Trypticase Soy Broth (TSB). The access chambers were filled with Staphylococcus epidermidis. Positive growth over thirty days was demonstrated by turbidity of the TSB. Vitek analysis was used to confirm the presence of S. epidermidis in the positive samples. Data evaluation consisted of a chi(2) analysis (p < 0.05). Although all experimental groups demonstrated leakage, tooth-colored MTA contaminated with saliva (group 3) leaked significantly more than the uncontaminated tooth-colored MTA (group 4) (p = 0.028).

Effects of an EPSPS-transgenic soybean line ZUTS31 on root-associated bacterial communities during field growth

PubMed Central

Cheng, Jing; Wang, Gu-Hao; Zhu, Yin-Ling; Zhang, Li-Ya; Shou, Hui-Xia; Qi, Jin-Liang

2018-01-01

The increased worldwide commercial cultivation of transgenic crops during the past 20 years is accompanied with potential effects on the soil microbial communities, because many rhizosphere and endosphere bacteria play important roles in promoting plant health and growth. Previous studies reported that transgenic plants exert differential effects on soil microbial communities, especially rhizobacteria. Thus, this study compared the soybean root-associated bacterial communities between a 5-enolpyruvylshikimate-3-phosphate synthase -transgenic soybean line (ZUTS31 or simply Z31) and its recipient cultivar (Huachun3 or simply HC3) at the vegetative, flowering, and seed-filling stages. High-throughput sequencing of 16S rRNA gene (16S rDNA) V4 hypervariable region amplicons via Illumina MiSeq and real-time quantitative PCR (qPCR) were performed. Our results revealed no significant differences in the overall alpha diversity of root-associated bacterial communities at the three developmental stages and in the beta diversity of root-associated bacterial communities at the flowering stage between Z31 and HC3 under field growth. However, significant differences in the beta diversity of rhizosphere bacterial communities were found at the vegetative and seed-filling stages between the two groups. Furthermore, the results of next generation sequencing and qPCR showed that the relative abundances of root-associated main nitrogen-fixing bacterial genera, especially Bradyrhizobium in the roots, evidently changed from the flowering stage to the seed-filling stage. In conclusion, Z31 exerts transitory effects on the taxonomic diversity of rhizosphere bacterial communities at the vegetative and seed-filling stages compared to the control under field conditions. In addition, soybean developmental change evidently influences the main symbiotic nitrogen-fixing bacterial genera in the roots from the flowering stage to the seed-filling stage. PMID:29408918

Outcome of Endodontic Surgery: A Meta-analysis of the Literature-Part 3: Comparison of Endodontic Microsurgical Techniques with 2 Different Root-end Filling Materials.

PubMed

Kohli, Meetu R; Berenji, Homayon; Setzer, Frank C; Lee, Su-Min; Karabucak, Bekir

2018-06-01

The aim of the present study was to investigate the influence of root-end preparation and filling material on endodontic surgery outcome. A systematic review and meta-analysis was conducted to determine the outcome of resin-based endodontic surgery (RES, the use of high-magnification preparation of a shallow and concave root-end cavity and bonded resin-based root-end filling material) versus endodontic microsurgery (EMS, the use of high-magnification ultrasonic root-end preparation and root-end filling with SuperEBA [Keystone Industries, Gibbstown, NJ], IRM [Dentsply Sirona, York, PA], mineral trioxide aggregate [MTA], or other calcium silicate cements). An exhaustive literature search was conducted to identify prognostic studies on the outcome of root-end surgery. Human studies conducted from 1966 to the end of December 2016 in 5 different languages (ie, English, French, German, Italian, and Spanish) were searched in 4 electronic databases (ie, Medline, Embase, PubMed, and Cochrane Library). Relevant review articles on the subject were scrutinized for cross-references. In addition, 5 dental and medical journals (Journal of Endodontics; International Endodontic Journal; Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontics; Journal of Oral and Maxillofacial Surgery; and International Journal of Oral and Maxillofacial Surgery) were hand checked dating back to 1975. All abstracts were screened by 3 independent reviewers (H.B., M.K., and F.S.). Strict inclusion-exclusion criteria were defined to identify relevant articles. Raw data were extracted from the full-text review of these selected articles independently by each of the 3 reviewers. In case of disagreement, an agreement was reached by discussion, and qualifying articles were assigned to group RES. For EMS, the same search strategy was performed for the time frame October 2009 to December 2016, whereas up to October 2009 the data were obtained from a previous systematic review with identical criteria and search strategy. Weighted pooled success rates and a relative risk assessment between RES and EMS were calculated. To make a comparison between groups, a random effects model was used. Sixty-eight articles were eligible for full-text review. Of these, per strict inclusion exclusion criteria, 14 studies qualified, 3 for RES (n = 862) and 11 for EMS (n = 915). Weighted pooled success rates for RES were 82.20% (95% confidence interval [CI], 0.7965-0.8476) and 94.42% for EMS (95% CI, 0.9295-0.9590). This difference was statistically significant (P < .0005). The probability for success for EMS proved to be significantly greater than the probability for success for RES, providing best available evidence on the influence of cavity preparation with ultrasonic tips and/or SuperEBA (Keystone Industries, Gibbstown, NJ), IRM (Dentsply Sirona, York, PA), MTA, or silicate cements as root-end filling material instead of a shallow cavity preparation and placement of a resin-based material. Additional large-scale randomized clinical trials are needed to assess other predictors of outcome. Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Effects of X-Ray Dose On Rhizosphere Studies Using X-Ray Computed Tomography

PubMed Central

Zappala, Susan; Helliwell, Jonathan R.; Tracy, Saoirse R.; Mairhofer, Stefan; Sturrock, Craig J.; Pridmore, Tony; Bennett, Malcolm; Mooney, Sacha J.

2013-01-01

X-ray Computed Tomography (CT) is a non-destructive imaging technique originally designed for diagnostic medicine, which was adopted for rhizosphere and soil science applications in the early 1980s. X-ray CT enables researchers to simultaneously visualise and quantify the heterogeneous soil matrix of mineral grains, organic matter, air-filled pores and water-filled pores. Additionally, X-ray CT allows visualisation of plant roots in situ without the need for traditional invasive methods such as root washing. However, one routinely unreported aspect of X-ray CT is the potential effect of X-ray dose on the soil-borne microorganisms and plants in rhizosphere investigations. Here we aimed to i) highlight the need for more consistent reporting of X-ray CT parameters for dose to sample, ii) to provide an overview of previously reported impacts of X-rays on soil microorganisms and plant roots and iii) present new data investigating the response of plant roots and microbial communities to X-ray exposure. Fewer than 5% of the 126 publications included in the literature review contained sufficient information to calculate dose and only 2.4% of the publications explicitly state an estimate of dose received by each sample. We conducted a study involving rice roots growing in soil, observing no significant difference between the numbers of root tips, root volume and total root length in scanned versus unscanned samples. In parallel, a soil microbe experiment scanning samples over a total of 24 weeks observed no significant difference between the scanned and unscanned microbial biomass values. We conclude from the literature review and our own experiments that X-ray CT does not impact plant growth or soil microbial populations when employing a low level of dose (<30 Gy). However, the call for higher throughput X-ray CT means that doses that biological samples receive are likely to increase and thus should be closely monitored. PMID:23840640

Push-out bond strength of root fillings made with C-Point and BC sealer versus gutta-percha and AH Plus after the instrumentation of oval canals with the Self-Adjusting File versus WaveOne.

PubMed

Pawar, A M; Pawar, S; Kfir, A; Pawar, M; Kokate, S

2016-04-01

To compare the push-out bond strength exhibited by root fillings performed with either C-Point and Endosequence® BC sealer™ (BC Sealer) or gutta-percha and AH Plus® after the instrumentation of oval canals with either the Self-Adjusting File (SAF) System or WaveOne (WO) reciprocating file. Eighty extracted premolars were selected and divided randomly into the following four groups (n = 20): group 1, SAF instrumentation and filling using gutta-percha and AH Plus sealer; group 2, SAF instrumentation and C-Point and BC sealer filling; group 3, WO instrumentation and filling using gutta-percha and AH Plus sealer; and group 4, WO instrumentation and filling with C-Point and BC sealer. Sodium hypochlorite (5.25%) and EDTA (17%) were used as irrigants for all groups. After the sealer was set completely, the teeth were prepared for micro push-out assessment using 1.0-mm-thick root slices. Loading was performed with a universal testing machine at a speed of 0.5 mm min(-1) . Two-way anova and Student's t-test for pairwise comparisons were used to compare groups. All specimens filled with C-Point and BC sealer were associated with significantly higher push-out bond strength compared with gutta-percha and AH Plus sealer (P < 0.001). The bond strength was higher for the coronal and apical samples of the C-Point/BC sealer/SAF group (6.6 ± 0.3 and 3.2 ± 0.3 MPa) versus those of the gutta-percha/AH Plus/WO group (4.8 ± 0.3 and 1.8 ± 0.3 MPa), by 38% and by 80% in the coronal and apical parts, respectively (P < 0.001, P < 0.0001). Adhesive bond failure was more common in the WaveOne-instrumented group in general and in the buccal and lingual recesses in this group in particular. In oval canals, the instrument used and the root filling material significantly affected the push-out values of root fillings. The highest value was recorded in oval root canals instrumented with the SAF System and filled with C-Point and BC sealer, whereas the lowest strength was noted in oval canals instrumented with WaveOne and filled with gutta-percha and AH Plus sealer. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Root proliferation in decaying roots and old root channels: A nutrient conservation mechanism in oligotrophic mangrove forests?

USGS Publications Warehouse

McKee, K.L.

2001-01-01

1. In oligotrophic habitats, proliferation of roots in nutrient-rich microsites may contribute to overall nutrient conservation by plants. Peat-based soils on mangrove islands in Belize are characterized by the presence of decaying roots and numerous old root channels (0.1-3.5 cm diameter) that become filled with living and highly branched roots of Rhizophora mangle and Avicennia germinans. The objectives of this study were to quantify the proliferation of roots in these microsites and to determine what causes this response. 2. Channels formed by the refractory remains of mangrove roots accounted for only 1-2% of total soil volume, but the proportion of roots found within channels varied from 9 to 24% of total live mass. Successive generations of roots growing inside increasingly smaller root channels were also found. 3. When artificial channels constructed of PVC pipe were buried in the peat for 2 years, those filled with nutrient-rich organic matter had six times more roots than empty or sand-filled channels, indicating a response to greater nutrient availability rather than to greater space or less impedance to root growth. 4. Root proliferation inside decaying roots may improve recovery of nutrients released from decomposing tissues before they can be leached or immobilized in this intertidal environment. Greatest root proliferation in channels occurred in interior forest zones characterized by greater soil waterlogging, which suggests that this may be a strategy for nutrient capture that minimizes oxygen losses from the whole root system. 5. Improved efficiency of nutrient acquisition at the individual plant level has implications for nutrient economy at the ecosystem level and may explain, in part, how mangroves persist and grow in nutrient-poor environments.

Single crowns versus conventional fillings for the restoration of root-filled teeth.

PubMed

Sequeira-Byron, Patrick; Fedorowicz, Zbys; Carter, Ben; Nasser, Mona; Alrowaili, Eman F

2015-09-25

Endodontic treatment involves removal of the dental pulp and its replacement by a root canal filling. Restoration of root filled teeth can be challenging due to structural differences between vital and non-vital root-filled teeth. Direct restoration involves placement of a restorative material e.g. amalgam or composite, directly into the tooth. Indirect restorations consist of cast metal or ceramic (porcelain) crowns. The choice of restoration depends on the amount of remaining tooth, and may influence durability and cost. The decision to use a post and core in addition to the crown is clinician driven. The comparative clinical performance of crowns or conventional fillings used to restore root-filled teeth is unknown. This review updates the original, which was published in 2012. To assess the effects of restoration of endodontically treated teeth (with or without post and core) by crowns versus conventional filling materials. We searched the following databases: the Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE via OVID, EMBASE via OVID, CINAHL via EBSCO, LILACS via BIREME. We also searched the reference lists of articles and ongoing trials registries.There were no restrictions regarding language or date of publication. The search is up-to-date as of 26 March 2015. Randomised controlled trials (RCTs) or quasi-randomised controlled trials in participants with permanent teeth that have undergone endodontic treatment. Single full coverage crowns compared with any type of filling materials for direct restoration or indirect partial restorations (e.g. inlays and onlays). Comparisons considered the type of post and core used (cast or prefabricated post), if any. Two review authors independently extracted data from the included trial and assessed its risk of bias. We carried out data analysis using the 'treatment as allocated' patient population, expressing estimates of intervention effect for dichotomous data as risk ratios, with 95% confidence intervals (CI). We included one trial, which was judged to be at high risk of performance, detection and attrition bias. The 117 participants with a root-filled, premolar tooth restored with a carbon fibre post, were randomised to either a full coverage metal-ceramic crown or direct adhesive composite restoration. None experienced a catastrophic failure (i.e. when the restoration cannot be repaired), although only 104 teeth were included in the final, three-year assessment. There was no clear difference between the crown and composite group and the composite only group for non-catastrophic failures of the restoration (1/54 versus 3/53; RR 0.33; 95% CI 0.04 to 3.05) or failures of the post (2/54 versus 1/53; RR 1.96; 95% CI 0.18 to 21.01) at three years. The quality of the evidence for these outcomes is very low. There was no evidence available for any of our secondary outcomes: patient satisfaction and quality of life, incidence or recurrence of caries, periodontal health status, and costs. There is insufficient evidence to assess the effects of crowns compared to conventional fillings for the restoration of root-filled teeth. Until more evidence becomes available, clinicians should continue to base decisions about how to restore root-filled teeth on their own clinical experience, whilst taking into consideration the individual circumstances and preferences of their patients.

Effects of zinc oxide-eugenol and calcium hydroxide/ iodoform on delaying root resorption in primary molars without successors.

PubMed

Lin, Bichen; Zhao, Yuming; Yang, Jie; Wang, Wenjun; Ge, Li-hong

2014-01-01

The purpose of this study was to compare the effects of zinc oxide-eugenol (ZOE) and calcium hydroxide/iodoform paste (Vitapex), as root canal filling materials in pulpectomy, on delaying the root resorption of primary molars without permanent successors. Animal models without permanent successors were surgically established in beagle dogs. Root resorption was observed via periapical radiographs. The onset of root resorption of primary mandibular molars without successors occurred later (p<0.05) than physiologic resorption. ZOE pulpectomy clearly delayed the root resorption of primary molars without permanent successors (p<0.05), whereas resorption of primary molars with Vitapex pulpectomy started at almost the same time as physiologic resorption. Compared with Vitapex, ZOE was a more effective root canal filling material in delaying the root resorption of primary molars.

A comparative evaluation of efficacy of protaper universal rotary retreatment system for gutta-percha removal with or without a solvent.

PubMed

Kumar, M Sita Ram; Sajjan, Girija S; Satish, Kalyan; Varma, K Madhu

2012-09-01

The aim was to evaluate and compare the efficacy of ProTaper Universal rotary retreatment system with or without solvent and stainless steel hand files for endodontic filling removal from root canals and also to compare retreatment time for each system. Thirty extracted mandibular premolars with single straight canals were endodontically treated. Teeth were divided into three major groups, having 10 specimens each. Removal of obturating material in group 1 by stainless steel hand files with RC Solve, group 2 by ProTaper Universal retreatment instruments and group 3 by ProTaper Universal retreatment instruments along with RC solve was done. Retreatment was considered complete for all groups when no filling material was observed on the instruments. The retreatment time was recorded for each tooth. All specimens were grooved longitudinally in a buccolingual direction. The split halves were examined under a stereomicroscope and images were captured and analyzed. The remaining filling debris area ratios were considered for statistical analysis. With ANOVA test, statistical analysis showed that there was statistically no significant difference regarding the amount of filling remnants between the groups (P < 0.05). Differences between the means of groups are statistically significant regarding the retreatment time. Irrespective of the technique used, all the specimens had some remnants on the root canal wall. ProTaper Universal retreatment system files alone proved to be faster than the other experimental groups.

Sealing ability of root-end filling materials.

PubMed

Amezcua, Octávio; Gonzalez, Álvaro Cruz; Borges, Álvaro Henrique; Bandeca, Matheus Coelho; Estrela, Cyntia Rodrigues de Araújo; Estrela, Carlos

2015-03-01

The aim of this research was to compare the apical sealing ability of different root-end filling materials (SuperEBA(®), ProRoot MTA(®), thermoplasticized gutta-percha + AH-Plus(®), thermoplasticized RealSeal(®)), by means of microbial indicators. Thus, 50 human single-rooted teeth were employed, which were shaped until size 5 0, retro - prepared with ultrasonic tips and assigned to 4 groups, retro-filled with each material or controls. A platform was employed, which was split in two halves: upper chamber-where the microbial suspension containing the biological indicators was introduced (E. faecalis + S. aureus + P. aeruginosa + B. subtilis + C. albicans); and a lower chamber containing the culture medium brain, heart influsion, where 3 mm of the apical region of teeth were kept immersed. Lectures were made daily for 60 days, using the turbidity of the culture medium as indicative of microbial contamination. Statistical analyses were carried out at 5% level of significance. The results showed microbial leakage at least in some specimens in all of the groups. RealSeal(®) has more microbial leakage, statistically significant, compared to ProRoot(®) MTA and SuperEBA(®). No significant differences were observed when compared ProRoot(®) MTA and SuperEBA(®). The gutta-percha + AH Plus results showed no statistically significant differences when compared with the other groups. All the tested materials showed microbial leakage. Root-end fillings with Super-EBA or MTA had the lowest bacterial filtration and RealSeal shows highest bacterial filtration.

Volumetric Evaluation of Different Obturation Techniques in Primary Teeth Using Spiral Computed Tomography.

PubMed

Nagaveni, N B; Yadav, Sneha; Poornima, P; Reddy, Vv Subba; Roshan, N M

Various obturation techniques have been evaluated for better filling of the root canals in primary teeth using different methods. Spiral Computed Tomography (SCT) is a new revolution in the pediatric endodontics for assessment of quality of the obturation from 3 dimensions. To evaluate the efficiency of 5 different obturation methods in delivering the filling material into the canals of primary teeth using Spiral Computed Tomography scan. A total of 50 canals of primary teeth were prepared, divided into 5 groups with 10 canals in each group and obturated with Zinc Oxide Eugenol cement using 5 different obturation techniques such as Local anesthetic syringe, Tuberculin syringe, Endodontic plugger, hand held Lentulo-spiral, and Lentulo-spiral mounted on slow speed hand piece. The pre and post obturation volume and finally the Percentage of Obturated Volume (POV) were calculated using SCT scan for each group. The data obtained was statistically analyzed using One-way Analysis of Variance (ANOVA) and Tukey's post-hoc test. Lentulo-spiral hand held showed highest POV value followed by Lentulospiral mounted to hand piece, Tuberculin syringe and Endodontic plugger; whereas Anesthetic syringe had least POV (P < 0.05). Lentulo-spiral hand held is the best obturating technique among the 5 groups evaluated as the canals of this group showed maximum percentage of filled material. However, a further study with large sample size is highly essential.

Sealing ability of MTA, CPM, and MBPc as root-end filling materials: a bacterial leakage study.

PubMed

Medeiros, Paulo Leal; Bernardineli, Norberti; Cavenago, Bruno Cavalini; Torres, Sérgio Aparecido; Duarte, Marco Antonio Hungaro; Bramante, Clovis Monteiro; Marciano, Marina Angélica

2016-04-01

Objectives To evaluate the sealing ability of three root-end filling materials (white MTA, CPM, and MBPc) using an Enterococcus faecalis leakage model. Material and Methods Seventy single-root extracted human teeth were instrumented and root-ends were resected to prepare 3 mm depth cavities. Root-end preparations were filled with white MTA, CPM, and MBPc cements. Enterococcus faecalis was coronally introduced and the apical portion was immersed in BHI culture medium with phenol red indicator. The bacterial leakage was monitored every 24 h for 4 weeks. The statistical analysis was performed using the Wilcoxon-Gehan test (p<0.05). Results All cements showed bacterial leakage after 24 hours, except for the negative control group. The MBPc showed significantly less bacterial leakage compared with the MTA group (p<0.05). No significant differences were found between the CPM and the other groups. Conclusions The epoxy resin-based cement MBPc had lower bacterial leakage compared with the calcium silicate-based cements MTA and CPM.

Investigation of Coronal Leakage of Root Fillings after Smear Layer Removal with EDTA or Er,Cr:YSGG Laser through Capillary Flow Porometry

PubMed Central

Vergauwen, Tom Edgard Maria; Michiels, Rafaël; Torbeyns, Dries; Meire, Maarten; De Moor, Roeland Jozef Gentil

2014-01-01

No studies have been performed evaluating the marginal seal of root fillings after direct exposure of root canal (RC) walls to Er,Cr:YSGG laser irradiation. Therefore, 75 root filled teeth (5 × 15–cold lateral condensation) were analyzed for through-and-through leakage (TTL) using capillary flow porometry (CFP). The cleaning protocol determined the experimental groups: (1) irrigation with NaOCl 2.5% and EDTA 17% or standard protocol (SP), (2) SP + Er,Cr:YSGG lasing (dried RC), (3) NaOCl 2.5% + Er,Cr:YSGG lasing (dried RC), (4) SP + Er,Cr:YSGG lasing (wet RC), and (5) NaOCl 2.5% + Er,Cr:YSGG lasing (wet RC). Groups 6 to 10 consisted of the same filled teeth with resected apices. Resection was performed after the first CFP measurement. CFP was used to assess minimum, mean flow, and maximum pore diameters after 48 h. Statistics were performed using nonparametric tests (P > 0.05). Additional three roots per group were submitted to SEM of the RC walls. TTL was observed in all groups without statistically significant differences between the different groups for minimum, mean, and maximum pore diameter (P > 0.05). In this study, the use of EDTA and/or Er,Cr:YSGG laser did not reduce through-and-through leakage in nonresected and resected roots. PMID:24696685

Spiral computed tomography assessment of the efficacy of different rotary versus hand retreatment system.

PubMed

Mittal, Neelam; Jain, Jyoti

2014-01-01

The purpose of this study was to evaluate the efficacy of nickel-titanium rotary retreatment systems versus stainless steel hand retreatment system with or without solvent for gutta-percha removal during retreatment. Sixty extracted human mandibular molar teeth with single canal in a distal root was prepared with ProTaper rotary nickel-titanium files and obturated with gutta-percha and sealer. The teeth were randomly divided into six groups of 10 specimens in each groups. The volume of filling material before and after retreatment were evaluated in cm(3) using the computed tomography (CT) scanner proprietary software. Maximum amount of filling material removed during retreatment with ProTaper retreatment system with solvent and minimum with hand retreatment system with solvent. None of the technique was 100% effective in removing the filling materials, but the ProTaper retreatment system with solvent was better.

Evaluation of Dentin Defect Formation during Retreatment with Hand and Rotary Instruments: A Micro-CT Study.

PubMed

Yilmaz, Ayca; Helvacioglu-Yigit, Dilek; Gur, Cansu; Ersev, Handan; Kiziltas Sendur, Gullu; Avcu, Egemen; Baydemir, Canan; Abbott, Paul Vincent

2017-01-01

The purpose of this study was to compare the incidence and longitudinal propagation of dentin defects after gutta-percha removal with hand and rotary instruments using microcomputed tomography. Twenty mandibular incisors were prepared using the balanced-force technique and scanned in a 19.9  μ m resolution. Following filling with the lateral compaction technique, gutta-percha was removed with ProTaper Universal Retreatment (PTUR) or hand instruments. After rescanning, a total of 24,120 cross-sectional images were analyzed. The numbers, types, and longitudinal length changes of defects were recorded. Defects were observed in 36.90% of the cross sections. A total of 73 defects were comprised of 87.67% craze lines, 2.73% partial cracks, and 9.58% fractures. No significant difference in terms of new defect formation was detected between the retreatment groups. The apical and middle portions of the roots had more dentin defects than the coronal portions. Defects in three roots of the PTUR instrument group increased in length. Under the conditions of this in vitro study, gutta-percha removal seemed to not increase the incidence of dentin defect formation, but the longitudinal defect propagation finding suggests possible cumulative dentinal damage due to additional endodontic procedures. Hand and rotary instrumentation techniques caused similar dentin defect formation during root canal retreatment.

Nd:YAG laser in endodontics: filling-material edge bordering on a root channel laser cavity

NASA Astrophysics Data System (ADS)

Belikov, Andrei V.; Sinelnik, Yuri A.; Moroz, Boris T.; Pavlovskaya, Irina V.

1997-12-01

For the very first time it is represented a study of filling material edge bordering upon root channel cavity modified with a laser. As a filling material it is used a glass ionomer cement. It is demonstrated that Nd:YAG laser radiation effects on increase of grade of edge bordering on the average of 20 - 30% at temperature rise of no more than 2 - 3 degrees in periodontium area in a period of operation.

Morphological Changes Of The Root Surface And Fracture Resistance After Treatment Of Root Fracture By CO2 Laser And Glass Ionomer Or Mineral Trioxide Aggregates

NASA Astrophysics Data System (ADS)

Badr, Y. A.; Abd El-Gawad, L. M.; Ghaith, M. E.

2009-09-01

This in vitro study evaluates the morphological changes of the root surface and fracture resistance after treatment of root cracks by CO2 laser and glass Ionomer or mineral trioxide aggregates (MTA). Fifty freshly extracted human maxillary central incisor teeth with similar dimension were selected. Crowns were sectioned at the cemento-enamel junction, and the lengths of the roots were adjusted to 13 mm. A longitudinal groove with a dimension of 1×5 mm2 and a depth of 1.5 mm was prepared by a high speed fissure bur on the labial surface of the root. The roots were divided into 5 groups: the 10 root grooves in group 1 were remained unfilled and were used as a control group. The 10 root grooves in group 2 were filled with glass Ionomer, 10 root grooves in group 3 were filled with MTA, the 10 root grooves in group 4 were filled with glass Ionomer and irradiated by CO2 laser and the 10 root grooves in group 5 were filled with MTA and irradiated with CO2 laser. Scanning electron microscopy was performed for two samples in each group. Tests for fracture strength were performed using a universal testing machine and a round tip of a diameter of 4 mm. The force was applied vertically with a constant speed of 1 mm min 1. For each root, the force at the time of fracture was recorded in Newtons. Results were evaluated statistically with ANOVA and Turkey's Honestly Significant Difference (HSD) tests. SEM micrographs revealed that the melted masses and the plate-like crystals formed a tight Chemical bond between the cementum and glass Ionomer and melted masses and globular like structure between cementum and MTA. The mean fracture resistance was the maximum fracture resistance in group 5 (810.8 N). Glass Ionomer and MTA with the help of CO2 laser can be an alternative to the treatment of tooth crack or fracture. CO2 laser increase the resistance of the teeth to fracture.

The effect of using an inverted master cone in a lateral compaction technique on the density of the gutta-percha fill.

PubMed

Wu, Min-Kai; de Groot, Sjoerd D; van der Sluis, Luc W M; Wesselink, Paul R

2003-09-01

We sought to measure and calculate the percentage of the gutta-percha-filled area in the apical root canal after the use of a standardized or inverted master cone in cold lateral compaction.Study design Two groups of extracted mandibular premolars with a single canal were instrumented with instruments of the same size; furthermore, they were obturated with laterally compacted gutta-percha cones with AH26 used as a sealer. In the first group, a standardized master cone was used with its narrow end in an apical position, whereas in the other group, an inverted master cone was used with its wide end in an apical position. The 2 master cones had the same apical diameter and fit in the apical canal. After lateral compaction, horizontal sections were cut at a level 3 and 5 mm from the apex of each filled tooth. Photographs of the sections were taken by using a microscope equipped with a digital camera; the photos were then scanned as tagged-image file format images. The cross-sectional area of the canal and the gutta-percha were measured by using an image-analysis program. The percentage of gutta-percha-filled area was calculated. At both levels, the inverted master cone produced a significantly higher percentage, statistically, of gutta-percha-filled area than did the standardized master cone (P =.001 at 3 mm; P =.012 at 5 mm). The use of an inverted master cone in cold lateral compaction may facilitate the apical placement of accessory cones, significantly increasing the volume of gutta-percha while reducing the volume of sealer in the apical root canal.

Resistance to vertical fracture of MTA-filled roots.

PubMed

EL-Ma'aita, Ahmad M; Qualtrough, Alison J E; Watts, David C

2014-02-01

To investigate the effect of MTA root canal fillings on the resistance to vertical root fracture (VRF) over different time intervals. Freshly extracted anterior human teeth with single canals and minimal curvatures were decoronated, instrumented to size 50/.05 ProTaper file, irrigated with 1%NaOCl and randomly allocated to one of three groups (n = 36): (i) filled with MTA, (ii) filled with gutta-percha and sealer and (iii) unfilled roots used as a negative control. Each group was subdivided into three subgroups (n = 12) according to the storage time of 48 h, 1 and 6 months at 37°C in synthetic tissue fluid (STF). Following the storage periods, filled roots were mounted in acrylic supports, and the periodontal ligament was simulated using elastomeric impression material. Vertical loading was carried out with a ball-ended steel cylinder fitted on a universal testing machine at 1 mm/min crosshead speed. The maximum force at fracture (F-max) and the fracture mode were recorded for each root. Data were statistically analysed using two-way anova and Bonferroni post hoc tests. The mean F-max was significantly higher in the MTA subgroups after 1 and 6 months compared with all other subgroups. Two modes of fracture were identified: split and comminuted. The mean F-max values recorded with the latter were significantly higher compared with the former (P < 0.001). In all groups, split fracture was the most dominant mode apart from the MTA/1 month and MTA/6 month groups. MTA increases the resistance to VRF of endodontically treated teeth and influences the mode of fracture after 1 and 6 month of storage in STF compared with gutta-percha and sealer. © 2013 John Wiley & Sons A/S.

Effect of Root Filling on Stress Distribution in Premolars with Endodontic-Periodontal Lesion: A Finite Elemental Analysis Study.

PubMed

Belli, Sema; Eraslan, Oğuz; Eskitascioglu, Gürcan

2016-01-01

Endodontic-periodontal (EP) lesions require both endodontic and periodontal therapies. Impermeable sealing of the root canal system after cleaning and shaping is essential for a successful endodontic treatment. However, complete healing of the hard and soft tissue lesions takes time, and diseased bone, periodontal ligament, and tooth fibrous joints are reported to have an increased failure risk for a given load. Considering that EP lesions may affect the biomechanics of teeth, this finite elemental analysis study aimed to test the effect of root fillings on stress distribution in premolars with EP lesions. Three finite elemental analysis models representing 3 different types of EP lesions (primary endodontic disease [PED], PED with secondary periodontic involvement, and true combined) were created. The root canals were assumed as nonfilled or filled with gutta-percha, gutta-percha/apical mineral trioxide aggregate (MTA) plug, and MTA-based sealer. Materials used were assumed to be homogenous and isotropic. A 300-N load was applied from the buccal cusp of the crown with a 135° angle. The Cosmoworks structural-analysis program (SolidWorks Corp, Waltham, MA) was used for analysis. Results were presented considering von Mises criteria. Stresses at the root apex increased with an increase in lesion dimensions. Root filling did not affect stress distribution in the PED model. An MTA plug or MTA-based sealer created more stress areas within the root compared with the others in the models representing PED with periodontic involvement and true combined lesions. Stresses at the apical end of the root increase with increases in lesion dimensions. MTA-based sealers or an MTA plug creates more stresses when there is periodontic involvement or a true combined lesion. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Clinical results with two different methods of root-end preparation and filling in apical surgery: mineral trioxide aggregate and adhesive resin composite.

PubMed

von Arx, Thomas; Hänni, Stefan; Jensen, Simon Storgård

2010-07-01

The aim of apical surgery is to hermetically seal the root canal system after root-end resection, thereby enabling periradicular healing. The objective of this nonrandomized prospective clinical study was to report results of 2 different root-end preparation and filling methods, ie, mineral trioxide aggregate (MTA) and an adhesive resin composite (Retroplast). The study included 353 consecutive cases with endodontic lesions limited to the periapical area. Root-end cavities were prepared with sonic microtips and filled with MTA (n = 178), or alternatively, a shallow concavity was prepared in the cut root face, with subsequent placement of an adhesive resin composite (Retroplast) (n = 175). Patients were recalled after 1 year. Cases were defined as healed when no clinical signs or symptoms were present and radiographs demonstrated complete or incomplete (scar tissue) healing of previous radiolucencies. The overall rate of healed cases was 85.5%. MTA-treated teeth demonstrated a significantly (P = .003) higher rate of healed cases (91.3%) compared with Retroplast-treated teeth (79.5%). Within the MTA group, 89.5%-100% of cases were classified as healed, depending on the type of treated tooth. In contrast, more variable rates ranging from 66.7%-100% were found in the Retroplast group. In particular, mandibular premolars and molars demonstrated considerably lower rates of healed cases when treated with Retroplast. MTA can be recommended for root-end filling in apical surgery, irrespective of the type of treated tooth. Retroplast should be used with caution for root-end sealing in apical surgery of mandibular premolars and molars. Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Morphologic study of tissue changes occurring in the apical third and periapex of rat molars after endodontic treatment performed under different occlusal conditions.

PubMed

Sato, E F; Antoniazzi, J H; Bauer, J A

1994-01-01

The purpose of the present study was to carry out a histologic study of the periapical changes of the maxillary first molar of rats submitted to endodontic treatment under different occlusal conditions. The experiment was carried out under conditions analogous to those used in clinical practice. Pulpotomy, pulpectomy and chemomechanical preparation of the mesial root canal were carried out according to previously established techniques and the mesial root canal was filled with cement and gutta-percha. A glass ionomer cement was used as restorative material under conditions of subocclusion, normal occlusion and excessive occlusal forces. No inflammatory reaction of periapical tissue was observed under the three conditions used, and active closing of the root canal was observed 15 days after the procedure, with the formation of cementum replacing the pulpar remnant.

Determination of the Apical Sealing Abilities of Mineral Trioxide Aggregate, Portland Cement, and Bioaggregate After Irrigation with Different Solutions.

PubMed

Bayram, H Melike; Saklar, Feridun; Bayram, Emre; Orucoglu, Hasan; Bozkurt, Alperen

2015-06-01

The purpose of this study was to investigate the sealing ability of root-end filling materials such as mineral trioxide aggregate (MTA), Portland cement, and bioaggregate (BA) after irrigation with different solutions. We examined 130 human maxillar central teeth. After cutting the teeth at the cementoenamel junction, the root canals were expanded using nickel-titanium rotary instruments. Root canals were filled with AH-plus and gutta-percha. Then, the roots were cut apically, and 3 mm deep retrograde cavities were prepared. The roots were divided 12 experimental groups, consisting 10 teeth each; the positive and negative control groups contained five teeth each. The retrograde cavities were rinsed using ethylenediaminetetraacetic acid (EDTA), chlorhexidine (CHX), BioPure(™) mixture of a tetracycline isomer, an acid, and a detergent (MTAD), or distilled water. Next, groups 1, 2, 3, and 4 were sealed with MTA; groups 5, 6, 7, and 8 were sealed with Portland cement; and groups 9, 10, 11, and 12 were sealed with BA. Then, apical microleakage was evaluated by using a computerized fluid filtration method. The results of the leakage test were statistically evaluated by the post-hoc Tukey's test. MTA, Portland cement, and BA root-end filling materials showed the least leakage in the CHX and distilled water groups. The highest leakage was observed in the EDTA and MTAD groups. The sealing ability of BA was as good as that of MTA. EDTA and MTAD increased the apical leakage and CHX and distilled water decreased the leakage of the root-end filling materials examined in this study.

Interleukin 1 gene cluster SNPs (rs1800587, rs1143634) influences post-orthodontic root resorption in endodontic and their contralateral vital control teeth differently.

PubMed

Iglesias-Linares, A; Yañez-Vico, R M; Ballesta, S; Ortiz-Ariza, E; Mendoza-Mendoza, A; Perea, E; Solano-Reina, E

2012-11-01

To investigate whether the genetic variants of the interleukin-1 gene cluster (IL1) are associated with a possible genetically induced variability in post-orthodontic external apical root resorption (EARR) in root filled teeth and their control counterparts with vital pulps. One hundred and forty-six maxillary premolars were evaluated radiographically following orthodontic treatment. Genetic screening was performed on orthodontic patients for two single-nucleotide polymorphisms (SNPs: rs1800587 and rs1143634) in the IL1 gene cluster. Subjects were divided into two groups according to the presence or absence of radiographic post-orthodontic EARR (>2 mm) in root filled teeth and their controls with vital pulps. Logistic regression analysis was performed to obtain an adjusted estimation between EARR and IL1 polymorphisms. Allelic frequencies, genotype distributions, and adjusted odds ratio (OR), at 95% confidence interval, were also calculated. Whilst no clear statistical association was found for gene variations in IL1A, a sound association was found in the comparative analysis of subjects homozygous [2/2(TT)] for the IL1B gene, which resulted in a two times increased risk of suffering post-orthodontic EARR in root filled teeth [OR, 2.032 (P = 0.031); CI,1.99-14.77] when compared with their controls with vital pulps. There was, however, a shared predisposition to EARR in controls with vital pulps and root filled teeth of subjects homozygous for allele 1 [OR, 5.05 (P = 0.002)] and [OR, 2.77 (P = 0.037)], respectively. Genetic variations in the interleukin-1β gene (rs1143634) predispose root filled teeth to EARR for matched pairs secondary to orthodontic treatment in a different way from their control teeth with vital pulps in subjects homozygous for allele 2 [2/2(TT)]. © 2012 International Endodontic Journal.

Determining the apical terminus of root-end resected teeth using three modern apex locators: a comparative ex vivo study.

PubMed

ElAyouti, A; Kimionis, I; Chu, A-L; Löst, C

2005-11-01

To assess ex vivo the accuracy of various electronic apex locators in locating the apical terminus of root-end resected teeth. Ninety extracted human posterior teeth (182 root canals) were prepared to a minimum size of 40 and filled with gutta-percha and sealer. After resection of the apical 3 mm of the root, the root canal filling was removed using HERO rotary instruments. The size of the root canal at the apical terminus after removal of the filling ranged from size 50 to 90. The root canal length to the apical terminus was determined using 3 apex locators (Root ZX, Raypex4 and Apex Pointer). A new mounting model that utilized a micrometer was used to perform the measurements and to visually determine the actual position of the apical terminus. The frequency of locating the apical terminus and the corresponding 95% confidence interval (CI) were calculated. Additionally, the coefficient of repeatability of each apex locator and the limits of inter-operator agreement were determined. All apex locators showed an acceptable repeatability (0.02-0.03 mm coefficient of repeatability) and narrow limits of inter-operator agreement (+0.07 and -0.07 mm). The accuracy of determining the apical terminus within 1 mm in the root canal was as follows: Root ZX 90% (164/182 root-canals) [95%CI: 86-94%], Raypex4 74% (135/182 root-canals) [95%CI: 68-80%], and Apex Pointer 71% (129/182 root canals) [95%CI: 65-77%]. No over-instrumentation resulted when the Root ZX device was used. In contrast, using the Raypex4 or the Apex Pointer device resulted in over-instrumentation in 8 of 182 root canals (4%). Under the conditions of this study all three apex locators were able to detect the apical terminus of root-end resected teeth with an acceptable range. The Root ZX device was the most accurate without over-instrumentation of the root canals.

Bacterial entombment by intratubular mineralization following orthograde mineral trioxide aggregate obturation: a scanning electron microscopy study

PubMed Central

Yoo, Jun Sang; Chang, Seok-Woo; Oh, So Ram; Perinpanayagam, Hiran; Lim, Sang-Min; Yoo, Yeon-Jee; Oh, Yeo-Rok; Woo, Sang-Bin; Han, Seung-Hyun; Zhu, Qiang; Kum, Kee-Yeon

2014-01-01

The time domain entombment of bacteria by intratubular mineralization following orthograde canal obturation with mineral trioxide aggregate (MTA) was studied by scanning electron microscopy (SEM). Single-rooted human premolars (n=60) were instrumented to an apical size #50/0.06 using ProFile and treated as follows: Group 1 (n=10) was filled with phosphate buffered saline (PBS); Group 2 (n=10) was incubated with Enterococcus faecalis for 3 weeks, and then filled with PBS; Group 3 (n=20) was obturated orthograde with a paste of OrthoMTA (BioMTA, Seoul, Korea) and PBS; and Group 4 (n=20) was incubated with E. faecalis for 3 weeks and then obturated with OrthoMTA–PBS paste. Following their treatments, the coronal openings were sealed with PBS-soaked cotton and intermediate restorative material (IRM), and the roots were then stored in PBS for 1, 2, 4, 8 or 16 weeks. After each incubation period, the roots were split and their dentin/MTA interfaces examined in both longitudinal and horizontal directions by SEM. There appeared to be an increase in intratubular mineralization over time in the OrthoMTA-filled roots (Groups 3 and 4). Furthermore, there was a gradual entombment of bacteria within the dentinal tubules in the E. faecalis inoculated MTA-filled roots (Group 4). Therefore, the orthograde obturation of root canals with OrthoMTA mixed with PBS may create a favorable environment for bacterial entombment by intratubular mineralization. PMID:25012869

The Comparative Efficacy of Different Files in The Removal of Different Sealers in Simulated Root Canal Retreatment- An In-vitro Study.

PubMed

Kanaparthy, Aruna; Kanaparthy, Rosaiah

2016-05-01

Root canal treatment enjoys a high success rate all over the world and has saved billions of teeth from extraction. However, there are instances of failure, the main causes being insufficient cleaning and inadequate obturation. In such cases the most conservative treatment option would be non-surgical retreatment. It requires regaining access to the entire root canal system through removal of the original root canal filling thus permitting further cleaning and re- obturation. Removal of gutta-percha and sealer becomes a critical step to gain access to the root canal system, remove necrotic tissue debris, bacteria and infected dentin. To compare and evaluate the efficacy of manual hand Hedstrom files and two rotary retreatment file systems ProTaper Universal retreatment files and Mtwo(R) (retreatment) files in the removal of root canal filling material during root canal retreatment and the influence of the type of sealers zinc oxide eugenol and AH plus on the presence of remaining debris in the reinstrumented canals in the apical, middle and coronal third. Sixty single rooted human premolar teeth were divided into 3 Groups of 20 teeth each Group I (20 Teeth): prepared using hand K Files, Group II (20 Teeth): prepared using ProTaper rotary system and Group III (20 Teeth): prepared using Mtwo rotary system. In Groups- IA, IIA, IIIA: (10 teeth each) Obturation was done using Zinc Oxide Eugenol sealer and gutta percha. In Groups- IB, IIB, IIIB: (10 teeth each) obturation was done with AH Plus sealer and gutta percha. All the teeth were subjected to retreatment. Groups IA and IB with Hedstrom files, Groups IIA and IIB with ProTaper retreatment files and for Groups IIIA and IIIB with Mtwo retreatment Files. The roots were longitudinally split and were observed under a stereomicroscope for remaining amount of filling material on the canal walls. Statistical analysis was done using One-way ANOVA (Analysis of variance) test and Tukey HSD Test. Mtwo(R) files showed statistically significant difference in the removal of filling material in the apical third and ProTaper R in the coronal and apical thirds. Better cleaning efficacy was seen in canals obturated with zinc oxide eugenol sealer. Mtwo(R) files showed better removal of filling material than ProTaper R followed by Hedstrom files, even though there was no statistically significant difference. None of the instrument group showed complete removal of the filling material. It was easier to remove zinc oxide eugenol sealer than AH plus sealer.

Periapical Status and Quality of Root Canal Fillings in a Moroccan Subpopulation

PubMed Central

El Merini, Hafsa; Lamzawaq, Amine; Hamza, Mouna

2017-01-01

Aim The aim of the study was to assess the prevalence of apical periodontitis (AP) and quality of root canal fillings in an adult Moroccan subpopulation. Methods In the study 508 patients were included, attending the Conservative Dentistry Clinic at the Faculty of Dentistry of Casablanca. 508 panoramic and 709 periapical radiographs were observed. The periapical status of all teeth (with the exception of third molars) was examined according to Ørstavik's periapical index. The statistical analysis was performed with the software Epi Info Version 6.04dfr, April 2001. Results A total of 12719 teeth were examined. 45.3% of patients had apical periodontitis. 4.2% of teeth were treated endodontically and 70.4% of these treatments were inadequate. 91,5% with inadequate endodontic treatment presented apical periodontitis, while only 8,2% with adequate endodontic treatment had apical periodontitis. The lower molars and the upper premolars were the most affected teeth. The presence of apical periodontitis was correlated significantly with insufficient root canal fillings (p < 0.05). Conclusions The present study found a high prevalence of apical periodontitis in this Moroccan population. Inadequate root canal fillings were associated with an increased prevalence of apical periodontitis. PMID:28713425

Root canal obturation: experimental study on the thermafil system related to different irrigation protocols

PubMed Central

Migliau, Guido; Sofan, Afrah Ali Abdullah; Sofan, Eshrak Ali Abdullah; Cosma, Salvatore; Eramo, Stefano; Gallottini, Livio

2014-01-01

Summary Aim The aim of this study was to stress the ability of a specific obturation technique (thermafil technique) to seal root canal system in presence or absence of smear layer. Methodology Sixteen monoradicular teeth, extracted for periodontal reasons, were collected for this study. All specimens were prepared with nickel-titanium rotary files, and then divided into two groups: for each group was applied a different kind of irrigation method, verifying the effectiveness in removing the smear layer, thus rendering the dentinal tubules more permeable for penetration of softened gutta-percha. Thermafil system was used to fill the root canals, and then all the specimens were observed under scanning electron microscope (SEM). Results The results showed that the Group which followed irrigation only with sodium hypochlorite exhibited significantly less gutta-percha tags when compared to the second Group, which was irrigated with sodium hypochlorite and EDTA. Conclusion The thermafil systems have a very good quality of compression and fluency that permit to gain a good seal of endodontic space; furthermore it allows the penetration of gutta-percha with the formation of numerous of gutta-percha tags inside the dentinal tubules above all when smear layer is reduced or eliminated. PMID:25506413

Arthroscopy Techniques: The Premier Arthroscopic Video Library.

PubMed

Leland, J Martin; Lubowitz, James H; Provencher, Matthew T

2016-12-01

Arthroscopy has always been focused on its roots-providing practical, clinically relevant information for the practicing arthroscopist. In the digital age, there is a need for publication platforms dedicated to multimedia presentations, hence the birth of Arthroscopy Techniques, Arthroscopy's online video companion. With over 700 videos, our library is filled with an exceptional collection of arthroscopic educational material, with topics ranging from the basics of arthroscopy to the most complex surgical procedures. One series, published this month, explores elbow arthroscopy with specific attention to describing various elbow portals, patient positioning, and tricks of elbow arthroscopy known only to the masters. If you have yet to view Arthroscopy Techniques, experience the future of arthroscopy today at www.ArthroscopyTechniques.org! Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Effect of different irrigation protocols on the radicular dentin interface and bond strength with a metacrylate-based endodontic sealer.

PubMed

Gonçalves, Lisandro; Silva-Sousa, Yara Teresinha Correa; Raucci Neto, Walter; Teixeira, Cleonice Silveira; Sousa-Neto, Manoel Damião; Alfredo, Edson

2014-06-01

This study assessed the influence of different endodontic chemical substances on the adhesion of the Epiphany SE/Resilon system (with and without resinous solvent) to radicular dentin walls, using the push-out test and scanning electron microscopy (SEM). Forty-eight root canals of human canines were prepared biomechanically with ProTaper rotary files (crown-down technique) and the radicular dentin was treated with either 17% EDTA, 2% chlorhexidine gel (CHX) or 2.5% NaOCl (control). The root canals were filled with Resilon cones and Epiphany SE sealer with and without resinous solvent. Six groups of eight canals each had their roots sectioned transversally to obtain 1-mm thick slices. Data were subjected to statistical analysis by ANOVA and Tukey's tests. The specimens treated with 17% EDTA (1.59 ± 0.91) presented higher bond strength (P < 0.05) than those treated with 2.5% NaOCl (0.93 ± 0.27) and 2% CHX (0.92 ± 0.22). Significantly higher bond strength (P < 0.05) was observed when the Epiphany SE was prepared with (1.37 ± 0.78) than without (0.92 ± 0.33) solvent. Adhesive failures were predominant in all groups. SEM analysis showed greater homogeneity of the filling mass when the solvent was added to the sealer. Treatment of root canal walls with 17% EDTA, and addition of a resinous solvent to Epiphany SE produced the highest adhesion to radicular dentin. © 2014 Wiley Periodicals, Inc.

Effects of EDTA gel preconditioning of periodontally affected human root surfaces on chlorhexidine substantivity - an SEM study.

PubMed

Gamal, Ahmed Y; Mailhot, Jason M

2007-09-01

Infection control is an important requirement during the early stages of periodontal healing. This study was performed to assess the preconditioning effect of EDTA gel on chlorhexidine (CHX) substantivity to periodontally involved root surfaces. Eighty patients with severe chronic periodontitis were enrolled in this study. Following cause-related therapy, patients were divided randomly into four groups. Each group consisted of 20 subjects with one tooth that was diagnosed as hopeless and designated for extraction. In group 1 (G1), selected periodontal pockets were filled with a placebo gel in a silica base for 2 minutes. Exposed roots in group 2 (G2) were etched for 2 minutes with a neutral EDTA conditioning agent, followed by pocket fill with the placebo gel. Pockets in group 3 (G3) were filled with 0.12% CHX digluconate gel in a silica base. Exposed roots in group 4 (G4) were etched for 2 minutes with a neutral EDTA conditioning agent, followed by pocket fill with the CHX gel. Four teeth from each group were extracted immediately and at 3, 12, 24, and 48 hours for SEM evaluation. G1 and G2 specimens showed no evidence of silica adherent to any of the examined root surfaces. At 3 hours following CHX gel application, G3 specimens showed marked reduction in CHX-coated silica. At 24 and 48 hours following EDTA and CHX gel application, G4 specimens demonstrated adherent CHX-coated silica particles despite the reclogging of the tubule orifices. EDTA and CHX gel root conditioning is a valuable regimen that improves CHX substantivity to periodontally involved root surfaces.

Root surface temperature variation during mechanical removal of root canal filling material. An in vitro study.

PubMed

García-Cuerva, Martín; Horvath, Lucía; Pinasco, Laura; Ciparelli, Verónica; Gualtieri, Ariel; Casadoumecq, Ana C; Rodríguez, Pablo; Gonzalez-Zanotto, Carlos

2017-04-01

The aim of this study was to analyze in vitro temperature changes on the outer surface of the dental root during mechanical filling removal procedures. Thirty recently extracted single-rooted lower premolars were cut transversally at 16 mm from the apex in order to standardize sample length. Endodontic treatment was performed on them. The filling material was subsequently removed using Gates Glidden (G1, G2, G3); Peeso (P1, P2, P3) and PostecPlus FRC (FRC) reamers while temperatures were measured on the outer surface using a digital device with thermocouple at 0, 2, 4, 6, 8, 10 and 15 seconds. Temperatures were compared using repeated measures ANOVA followed by pairwise comparison with Tukey's test. All reamers caused significant temperature variation between different times (p<0.05). Pairwise comparisons indicated that temperature increased with time for all reamers (p<0.05). Significant differences in temperature were found between different reamers after 0, 2, 4, 6, 8,10 and 15 seconds (p<0.05). Temperature at the root surface increased considerably. Values higher than 50°C were recorded, the greatest increase from baseline being 16°C. Accordingly, if the procedure were begun at 37°C (physiological temperature), the temperature in the surrounding tissues - cementum, periodontium and bone - would rise to 53°C. An increase in 10°C above body temperature at the root surface may cause lesions in surrounding tissues. While removing filling material, it is essential to cool, control action time and use instruments in perfect condition, all of which may contribute to reducing the heat generated and transmitted to the outer root surface. Sociedad Argentina de Pediatría.

How accurate replicates the Thermafil System the morphology of the apical endodontic space? An ex vivo study.

PubMed

Stratul, S I; Didilescu, Andreea; Grigorie, Mihaela; Ianes, Emilia; Rusu, D; Nica, Luminiţa

2011-01-01

To evaluate the morphology of the root canal in its apical third and the capacity of the Thermafil System to reproduce the entire morphology of the cleaned and shaped root canal. Thirty-two roots of periodontally compromised teeth were prepared using the ProTaper System to an apical size 30 and filled with the Thermafil obturation technique and sealer. The roots were surgically amputated and prepared for metallographic evaluation by incremental reductions of 0.5 mm each, starting with the apical foramen. Photomicrographs of each section were taken at a magnification of 500x and 100x. The images were analyzed and processed. The position of the apical foramen with respect to the anatomical apex was identified and marked. Additional morphological details as lateral canals and recesses were also recorded. The cross-sectioned area of the canal and gutta-percha, the total perimeter, the shaped perimeter and the filled perimeter were recorded for each sample and the results were expressed as percentages. Multiple images of successive sections were used to create a 3D reconstruction of the apical anatomy of the tooth. The ANOVA test was performed to assess mean differences between evaluations of perimeters/areas at different levels. The anatomical apical foramen was found at the tip of the root in 50% of the evaluated samples. In the remaining samples, the foramen was located between 0.5 and 2.5 mm from the centre of the apex. Lateral canals, which opened in accessory foramens, were recorded in 25% of the evaluated samples. Statistical significant differences (p<0.05) were found between different levels of preparation and obturation. The complex morphology of the apical third of the root canal is satisfactory microstructurally replicated by the Thermafil System. Moreover, polarized light microscopy and the 3D reconstruction offered a discriminative vision of morphological details as lateral canals, recesses, the gutta-percha and debris.

Interleukin 1 receptor antagonist (IL1RN) genetic variations condition post-orthodontic external root resorption in endodontically-treated teeth.

PubMed

Iglesias-Linares, Alejandro; Yañez-Vico, Rosa Ma; Ballesta-Mudarra, Sofía; Ortiz-Ariza, Estefanía; Mendoza-Mendoza, Asunción; Perea-Pérez, Evelio; Moreno-Fernández, Ana Ma; Solano-Reina, Enrique

2013-06-01

External apical root resorption (EARR) is a frequent iatrogenic problem following orthodontic treatment in endodontically-treated teeth, about which the literature reports substantial variability in post-orthodontic treatment EARR responses. The main focus of the present study is to clarify whether variants in the interleukin-1 receptor antagonist gene coding for the IL-1ra protein have a positive/negative influence on EARR of endodontically-treated teeth. Ninety-three orthodontic patients were genetically screened for a single nucleotide polymorphism (SNP:rs419598) in the IL1 cluster. The sample was classified into 2 groups: group 1 (affected-group) showed radiographic EARR of more than 2mm; group 2 (control-group), had no EARR or EARR ≤ to 2mm following orthodontic treatment on root-filled teeth. Logistic regression analysis was performed to obtain an adjusted estimate between the SNPs studied and EARR. Genotype distributions, allelic frequencies, adjusted odds ratios (OR) and 95% confidence intervals were also calculated. We found that subjects homozygous [1/1(TT)] for the IL1RN gene [OR:10.85; p=0.001;CI:95%] were at risk of EARR in root-filled teeth. Genetic variants in the antagonist axis balance of the IL1RN (rs419598) have a direct repercussion on the predisposition to post-orthodontic EARR in root-filled teeth. Variants in allele 1 of the interleukin-1 receptor antagonist gene(rs419598) are associated(p=0.001**) with an increased risk of suffering post-orthodontic EARR in root-filled teeth.

The effect of chloroform, orange oil and eucalyptol on root canal transportation in endodontic retreatment.

PubMed

Karataş, Ertuğrul; Kol, Elif; Bayrakdar, İbrahim Şevki; Arslan, Hakan

2016-04-01

The purpose of the present study was to assess the effect of solvents on root canal transportation in endodontic retreatment. Sixty extracted human permanent mandibular first molars with curved root canals were selected. All of the root canals were prepared using Twisted File Adaptive instruments (SybronEndo, Orange, CA, USA) and filled with gutta-percha and AH Plus sealer (Dentsply DeTrey, Konstanz, Germany) using the cold lateral compaction technique. The teeth were assigned to four retreatment groups as follows (n = 15): eucalyptol, chloroform, orange oil and control. The canals were scanned using cone-beam computed tomography scanning before and after instrumentation. The chloroform group showed a significantly higher mean transportation value than the orange oil and control groups at the 3 and 5 mm levels (P = 0.011 and P = 0.003, respectively). There was no significant difference among the orange oil, eucalyptol and control groups in terms of canal transportation (P > 0.61). The chloroform led to more canal transportation than the eucalyptol and orange oil during endodontic retreatment. © 2015 Australian Society of Endodontology.

[A prognostic model for assessment of outcome of root canal treatment in teeth with pulpitis or apical periodontitis].

PubMed

Zhang, M M; Zheng, Y D; Liang, Y H

2018-02-18

To present a prognostic model for evaluating the outcome of root canal treatment in teeth with pulpitis or apical periodontitis 2 years after treatment. The implementation of this study was based on a retrospective study on the 2-year outcome of root canal treatment. A cohort of 360 teeth, which received treatment and review, were chosen to build up the total sample size. In the study, 143 teeth with vital pulp and 217 teeth with apical periodontitis were included. About 67% of the samples were selected randomly to derive a training date set for modeling, and the others were used as validating date set for testing. Logistic regression models were used to produce the prognostic models. The dependent variable was defined as absence of periapical lesion or reduction of periapical lesion. The predictability of the models was evaluated by the area under the receiver-operating characteristic (ROC) curve (AUC). Four predictors were included in model one (absence of apical lesion): pre-operative periapical radiolucency, canal curvature, density and apical extent of root fillings. The AUC was 0.802 (95%CI: 0.744-0.859). And the AUC of the testing date was 0.688. Only the density and apical extent of root fillings were included to present model two (reduction of apical lesion). The AUC of training dates and testing dates were 0.734 (95%CI: 0.612-0.856) and 0.681, respectively. As predicted by model one, the probability of absence of periapical lesion 2 years after endodontic treatment was 90% in pulpitis teeth with sever root-canal curvature and adequate root canal fillings, but 51% in teeth with apical periodontitis. When using prognostic model two for prediction, in teeth with apical periodontitis, the probability of detecting lesion reduction with adequate or inadequate root fillings was 95% and 39% 2 years after treatment. The pre-operative periapical status, canal curvature and quality of root canal treatment could be used to predict the 2-year outcome of root canal treatment.

Comparative evaluation of the vertical fracture resistance of endodontically treated roots filled with Gutta-percha and Resilon: a meta-analysis of in vitro studies.

PubMed

Tan, Minmin; Chai, Zhaowu; Sun, Chengjun; Hu, Bo; Gao, Xiang; Chen, Yunjia; Song, Jinlin

2018-06-13

Teeth treated endodontically are more susceptible to vertical root fracture (VRF). Some studies have suggested that obturating the root canals with Gutta-percha or Resilon can reinforce endodontically treated teeth, but a few others have presented conflicting results. These inconsistent results cannot guide clinicians in determining clinical approaches. The objective of this meta-analysis is to evaluate and compare the vertical fracture resistance of endodontically treated root canals obturated with Gutta-percha/AH plus and the Resilon system. Comprehensive literature searches were performed in the PubMed, Cochrane Library, ScienceDirect, Web of Science and Embase databases. The titles and abstracts of all of the retrieved articles were independently assessed by two authors according to predefined selection criteria. Data in the included articles were independently extracted. Statistical analyses were conducted using Review Manager 5.3 and Stata 12.0 software. The pooled standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated for the outcome indicators. The level of statistical significance was set at p < 0.05. The Cochran Q test (I 2 test) was used to test for heterogeneity among studies. Fourteen randomized controlled in vitro trials were included in the meta-analysis. The results demonstrated that the vertical root fracture resistance of unprepared and unfilled roots was significantly higher than that of roots obturated with Gutta-percha/AH plus (SMD = - 0.69, 95% CI = - 1.34 to - 0.04, p = 0.04) or the Resilon system (SMD = - 0.54, 95% CI = - 1.07 to - 0.00, p = 0.05). The differences in fracture resistance between the roots filled with Gutta-percha/AH plus and the prepared unfilled root canals was not significant (SMD = 0.59, 95% CI = - 0.02 to 1.21, p = 0.06). Roots obturated with Resilon had higher fracture resistance than instrumented unfilled roots (SMD = 0.83, 95% CI = 0.44 to 1.22, p < 0.0001) or roots filled with Gutta-percha/AH plus (SMD = 0.62, 95% CI = 0.01 to 1.23, p = 0.05). The present study suggests that filling with Gutta-percha/AH plus dose not reinforce endodontically treated roots, whereas obturating with the Resilon system can increase vertical root fracture resistance of prepared roots. As this meta-analysis was based on in vitro studies, it should be careful to extrapolate its conclusion to the clinical context.

Orthograde retreatment failure with extruded MTA apical plug in a large periradicular lesion followed by surgical intervention: case report.

PubMed

Brito-Junior, Manoel; Faria-e-Silva, Andre Luis; Quintino, Alex Carvalho; Moreira-Junior, Gil; Geber, Mauro; Camilo, Carla Cristina; Soares, Janir Alves

2012-01-01

Absence of periapical healing after orthograde retreatment using an apical plug with mineral trioxide aggregate (MTA) can require surgical intervention. A patient with a root-filled maxillary central incisor with chronic apical periodontitis and sinus tract was referred for endodontic retreatment. Excessive apical enlargement was verified, indicating an MTA apical plug placement; however, an unintentional extrusion of MTA occurred during this step. The root canal was filled with gutta-percha and sealer, and periodic recalls were scheduled. The sinus tract was observed after six months and the lesion remained unaltered, although the extruded MTA had resorbed; therefore, an apicoectomy and retrograde root-end filling with MTA were performed. Absence of sinus tract, normal clinical aspect, and complete repair of the lesion were observed at the two-year follow-up.

Evaluation of apically extruded debris during root canal retreatment with several NiTi systems.

PubMed

Dincer, A N; Er, O; Canakci, B C

2015-12-01

To compare the amount of debris extruded apically during root canal retreatment using ProTaper, Mtwo and Reciproc instruments with hand H-files. In total, 60 freshly extracted human mandibular incisor teeth were used. All root canals were prepared with a Reciproc R25 file than filled with Gutta-percha and AH Plus sealer using cold lateral condensation before being assigned randomly to four groups (n = 15 each). In group 1, root fillings were removed with the Protaper Universal retreatment system; ProTaper Universal F3 and F4 instruments were used for the final preparation. In group 2, root fillings were removed with the Mtwo retreatment system; Mtwo size 30, .06 taper, size 35, .06 taper and size 40, .06 taper files were used for the final preparation. In group 3, root fillings were removed with Reciproc R25 instruments; Reciproc R40 instruments were used for the final preparation. In group 4, the root fillings were removed with Gates Glidden burs and sizes 35, 30 and 25 H-files; for final preparation, a size 40 H-file was used. Glass vials were used for debris collection. The vials were weighed before and after Gutta-percha removal. Additionally, the times required for the retreatment procedures were recorded. Data were analysed statistically using one-way analysis of variance. The Reciproc system produced significantly smaller amounts of apical extruded debris than the other groups (P < 0.05). There was no significant difference between the Mtwo, H-file and ProTaper groups. The ProTaper and Reciproc groups required significantly less time than the Mtwo and H-file groups (P < 0.001). Use of the reciprocating single file system resulted in the extrusion of significantly less debris compared with the full-sequence rotary NiTi instruments and hand filing. Use of the ProTaper and Reciproc instruments required less time for retreatment procedures than use of the Mtwo or H-file. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Rooting traits of peanut genotypes with different yield response to terminal drought

USDA-ARS?s Scientific Manuscript database

Drought at pod filling and maturity stages can severely reduce yield of peanut. Better root systems can reduce yield loss from drought. The goal of this study was to investigate the responses to terminal drought of peanut genotypes for root dry weight and root length density. A field experiment was ...

Use of calcium-containing endodontic sealers as apical barrier in fluid-contaminated wide-open apices.

PubMed

Prati, Carlo; Siboni, Francesco; Polimeni, Antonella; Bossu, Maurizio; Gandolfi, Maria Giovanna

2014-12-30

The sealing of wide-open apex roots is still a challenge and requires the use of apical barrier techniques. The aim was to evaluate ex vivo the sealing and the apical morphology of 3 commercial calcium oxide (CaO)-containing sealers - namely, 2 zinc oxide-based (CRCS and Sealapex) and a calcium silicate MTA-based (TechBiosealer Endo) - placed in wet root canals with artificial wide-open apices.
 Thirty human single-rooted teeth were shaped with Protaper and an artificial open apex (diameter size 110) was created. Each root was inserted in a custom-designed support containing simulated body fluid (Hank's balanced salt solution, HBSS) at the bottom simulating the presence of periapical fluid in the canal. Each sealer (TechBiosealer Endo, CRCS, Sealapex) was compacted to the apical 5 mm and the filled roots stored in HBSS at 37°C. The sealing was evaluated as microinfiltrated fluid since 24 hours up to 6 months using a high-precision digital fluid flow meter. The sealers were also studied for setting time in HBSS, calcium releasing (statistical analysis by 2-way ANOVA followed by Student-Newman-Keuls test, P<0.05) and surface morpho-chemistry by ESEM-EDX and OM analysis.
 All sealers showed a stable seal. TechBiosealer Endo maintained a better seal than the other materials (P<0.05) and ESEM-EDX and OM analyses showed the presence of apatite deposits.
 The clinical use of hydraulic hydrophilic MTA-based sealers can be recommended to stop/reduce the fluid flow rate through the apex. The artificial apical barrier in wet wide apices is a suitable technique able to seal wet root canals.

In Vitro Regeneration of Endangered Medicinal Plant Heliotropium kotschyi (Ramram).

PubMed

Sadeq, Manal Ahmed; Pathak, Malabika Roy; Salih, Ahmed Ali; Abido, Mohammed; Abahussain, Asma

2016-01-01

Heliotropium kotschyi (Ramram) is an important endangered medicinal plant distributed in the Kingdom of Bahrain. Plant tissue culture technique is applied for ex situ conservation study. Nodal stem segments are cultured in modified MS media supplemented with various combination and concentration of plant growth regulators (PGRs). Plants are regenerated via shoot organogenesis from the nodal meristems. Plants are regenerated in three different steps: initial shoot development, shoot multiplication, and rooting. After 4 weeks of culture, 100 % explants respond to shoot initiation on the medium containing 8.88 μM BAP and 5.71 μM IAA. The highest frequency of shoot regeneration is observed in the same media after second subculture of shoots. The highest rooting frequency is observed in the presence of 2.85 μM IAA. After root development, the plantlets are transferred to pots filled with soil and 60 % of plants survived after 45 days. This plant regeneration protocol is of great value for rapid desert plant propagation program.

Apical sealing ability of Resilon/Epiphany versus gutta-percha/AH Plus: immediate and 16-months leakage.

PubMed

Paqué, F; Sirtes, G

2007-09-01

To compare the long-term apical sealing ability of gutta-percha/AH Plus and Resilon/Epiphany. The root canals of 90 single-rooted human mandibular premolars with single narrow root canals were prepared with ProFile 0.4 taper instruments to apical size 40. After each instrument, the canals were irrigated with 1% sodium hypochlorite. Subsequently, the teeth were randomly divided into four groups containing 20 teeth each. Additionally, 10 prepared premolars served as positive and 10 counterparts with intact crowns as negative controls. The root canals were filled with gutta-percha/AH Plus or Resilon/Epiphany using lateral or vertical compaction. Specimens were allowed to set for 7 days at 37 degrees C and 100% humidity. Subsequently, the root fillings were removed down to the apical 4 mm. Fluid movement was then assessed using a fluid transportation model and re-evaluated after 16 months of water storage. Leakage within and between groups was compared using nonparametric tests. Negative controls revealed no fluid movement and positive controls displayed gross fluid movement at both times of observation. At the immediate measurement, there were no significant differences between the experimental groups (Kruskal-Wallis, P > 0.05). Gutta-percha/AH Plus fillings retained their seal after 16-months storage (Wilcoxon, P > 0.05), whilst the Resilon/Epiphany groups lost their sealing capacity (Wilcoxon, P < 0.001). In these groups, 29 of the 40 specimens exhibited gross leakage similar to positive controls. Initially, Resilon/Epiphany root fillings prevented fluid movement to the same degree as gutta-percha/AH Plus counterparts, but showed more fluid movement when tested at 16 months.

Fracture resistance of immature teeth filled with BioAggregate, mineral trioxide aggregate and calcium hydroxide.

PubMed

Tuna, Elif Bahar; Dinçol, Muzaffer Emir; Gençay, Koray; Aktören, Oya

2011-06-01

Abstract -  Background: The aim of this in vitro study was to assess the long-term fracture resistance of human immature permanent teeth filled with BioAggregate (BA), mineral trioxide aggregate (MTA) and calcium hydroxide (CH).  The study consisted of single rooted premolar teeth with immature root formation extracted for orthodontic reasons. A total of 28 immature premolars with average root length of 10.7 mm and apical diameter of 3 mm were included in the study. The pulps were extirpated and the canals were prepared using an apical approach. The teeth were randomly assigned to four groups: Group I: DiaRoot(®) BA (DiaDent, Burnaby, BC, Canada), Group II: Angelus MTA (MTA-A; Angelus, Londrina, Brazil), Group III: ProRoot(®) MTA (MTA-PR; Dentsply, Tulsa, OK, USA), Group IV: CH (Sultan Chemists Inc., Englewood, NJ, USA). The teeth were placed in saline solution at 4°C for 1 year. The root of each tooth was then embedded in an acrylic resin block. All specimens were loaded at a crosshead speed of 1 mm min(-1) in an Instron testing machine and the peak loads up to fracture were recorded. Data were analysed statistically by Kruskal-Wallis and Mann-Whitney U-tests.  Mean (±SD) failure loads (MPa) were: 37.69 ± 14.43 for BA group, 32.94 ± 8.15 for MTA-A group, 28.74 ± 9.49 for MTA-PR group and 23.18 ± 8.48 for CH group. The BA group exhibited the highest fracture resistance and the CH group showed the lowest resistance to fracture. Significant differences (P < 0.05) in fracture resistance were found between the DiaRoot-BA and CH groups, and also between the MTA-A and CH groups.  Within the limitations of this study, data suggest that DiaRoot-BA-filled immature teeth demonstrate higher fracture resistance than other groups at 1 year. Considering the long-term risk of cervical root fracture associated with immature teeth, the use of DiaRoot-BA as a root canal filling material appears to be the most advantageous of the materials tested. © 2011 John Wiley & Sons A/S.

Evaluation of physicochemical properties of root-end filling materials using conventional and Micro-CT tests.

PubMed

Torres, Fernanda Ferrari Esteves; Bosso-Martelo, Roberta; Espir, Camila Galletti; Cirelli, Joni Augusto; Guerreiro-Tanomaru, Juliane Maria; Tanomaru-Filho, Mario

2017-01-01

To evaluate solubility, dimensional stability, filling ability and volumetric change of root-end filling materials using conventional tests and new Micro-CT-based methods. 7. The results suggested correlated or complementary data between the proposed tests. At 7 days, BIO showed higher solubility and at 30 days, showed higher volumetric change in comparison with MTA (p<0.05). With regard to volumetric change, the tested materials were similar (p>0.05) at 7 days. At 30 days, they presented similar solubility. BIO and MTA showed higher dimensional stability than ZOE (p<0.05). ZOE and BIO showed higher filling ability (p<0.05). ZOE presented a higher dimensional change, and BIO had greater solubility after 7 days. BIO presented filling ability and dimensional stability, but greater volumetric change than MTA after 30 days. Micro-CT can provide important data on the physicochemical properties of materials complementing conventional tests.

The antimicrobial effectiveness of photodynamic therapy used as an addition to the conventional endodontic re-treatment: a clinical study.

PubMed

Jurič, Ivona Bago; Plečko, Vanda; Pandurić, Dragana Gabrić; Anić, Ivica

2014-12-01

The purpose of the study was to evaluate the efficacy of antimicrobial photodynamic therapy (aPDT) used as an adjunct to the endodontic re-treatment in the eradication of microorganisms from previously filled root canals. The study sample consisted of 21 randomly selected patients with root filled and infected root canal system with chronic apical periodontitis on incisors or canines, who have had previously endodontic treatment. Microbiological samples from the root canals were collected after accessing the canal, following the endodontic re-treatment and after the aPDT procedure. During instrumentation, the root canals were irrigated with 2.5% sodium hypochlorite (NaOCl), and the final irrigation protocol included 17% ethylenediaminetetraacetic acid followed by NaOCl. Root canals were filled with a phenothiazinium chloride and irradiated with a diode laser (λ=660 nm, 100 mW) for 1 min. Microbiological samples from the root canals were cultivated on selective plates, and the identification was done by micromorphology, macromorphology and different API strips as well as bacterial counts (colony forming units). Fourteen bacteria species were isolated from the root canals initially, with a mean value of 4.57 species per canal. Although endodontic re-treatment alone produced a significant reduction in the number of bacteria species (p<0.001), the combination of endodontic treatment and aPDT was statistically more effective (p<0.001). No bacteria were cultivated from the main root canals of 11 teeth. The results indicated that the aPDT used as an adjunct to the conventional endodontic therapy achieved a significant further reduction of intracanal microbial load. Copyright © 2014 Elsevier B.V. All rights reserved.

Flare up rate related to root canal treatment of asymptomatic pulpally necrotic central incisor teeth in patients attending a military hospital.

PubMed

Al-Negrish, Abdul Rohman Salem; Habahbeh, Riyad

2006-10-01

This prospective study was conducted to determine the flare up rate related to root canal treatment of asymptomatic non vital maxillary central incisor teeth performed in one and two appointments and the relationship, if any between pain and number of treatment visits. The frequency of postobturation pain and swelling was recorded and evaluated over an observation period of 1 week in a 120 consecutive patients undergoing root canal treatment. The patients were assigned randomly into one of two groups of 60 patients each. The canals of all teeth were prepared and filled using the step-back preparation and lateral condensation filling techniques. The data were analyzed statistically using Mann-Whitney test. Eight of the 120 patients were excluded from the analysis as they failed to attend for postoperative reviews. Out of the 112 patients involved in the study 90 patients had no pain, 9 patients had slight pain, 8 patients had moderate pain, and 5 patients had severe pain after 2 days. After 7 days 104 patients had no pain, 4 patients had slight pain, 3 patients had moderate pain and 1 patient had severe pain. No statistically significant difference in the incidence and degree of postoperative pain was found between one and two visit Endodontic procedures. The rate of post obturation flare up in asymptomatic Endodontically treated non vital maxillary centarl incisors was 11.6 and 3.6% after 2 and 7 days, respectively.

[Evaluation of labial surface root filling combined with porcelain dental restoration].

PubMed

Liu, Yuan-qiao; Huang, Zhi-hua; Hu, Huan-yu

2015-04-01

To analyze the effect of porcelain dental restoration combined with labial surface root filling for the anterior teeth. One hundred cases with anterior teeth protrusion treated in our department from January 2010 to January 2014 underwent porcelain dental restoration combined with labial surface root filling. The measurements in cephalometric X-ray films before and after treatment were compared, and porcelain dental appearance and function were evaluated. The data was statistically analyzed with SPSS18.0 software package. After treatment, U1-SN, U1-X, U1-Y were significantly lower than before treatment (P<0.01). U1-L1 was significantly higher after treatment (P<0.01). The incidence of gingivitis after treatment decreased significantly (X(2)=16.2749,P=0.0000<0.01). The excellent rate of outline of porcelain teeth after treatment, correction of protruding anterior teeth, fitting with adjacent teeth and alleviation of deep overbite and deep cover was 96.00%, 95.00%, 98.00% and 91.00%, respectively. Porcelain dental restoration after root canal treatment can effectively improve anterior teeth protrusion and increase the aesthetic appearance, which is worthy of clinical application.

A comparative evaluation of sealing ability of four root end filling materials using fluid filtration method: An in vitro study

PubMed Central

Shetty, Shilpa; Hiremath, Geeta; Yeli, Mahantesh

2017-01-01

Aim of the Study: The aim of this study was to compare and evaluate the sealing ability of four root end filling materials mineral trioxide aggregate (MTA)-Plus, Biodentine, MTA (MTA Angelus) and glass ionomer cement (GIC) using fluid filtration method. Materials and Methods: Forty-four extracted, human single-rooted teeth were collected. The crown of each tooth was decoronated 2 mm above the cementoenamel junction. Canals were negotiated, instrumented, obturated using lateral compaction method. The access cavities were sealed with Cavit. Root end resection and apical root end cavity preparations of 4 mm were made in each specimen. The selected roots were then randomly divided into four groups (n = 11) and restored as follows. Group 1 – GIC, Group 2 – MTA (MTA Angelus), Group 3 – Biodentine, and Group 4 – MTA Plus. The apical microleakage of each specimen was assessed using fluid filtration method at 72 h, 1 month and 3 months. Microleakage in each specimen was recorded in mm (millimeter) and converted to μl/min/cm H2O. Results: MTA Angelus showed least microleakage followed by Biodentine and MTA Plus. Least sealing ability was seen with GIC. There was statistically significant difference between all the materials at various time intervals. Conclusion: MTA Angelus showed superior sealing ability as a retrograde filling material followed by Biodentine and MTA Plus. PMID:29386776

Microorganism penetration in dentinal tubules of instrumented and retreated root canal walls. In vitro SEM study.

PubMed

Al-Nazhan, Saad; Al-Sulaiman, Alaa; Al-Rasheed, Fellwa; Alnajjar, Fatimah; Al-Abdulwahab, Bander; Al-Badah, Abdulhakeem

2014-11-01

This in vitro study aimed to investigate the ability of Candida albicans (C. albicans) and Enterococcus faecalis (E. faecalis) to penetrate dentinal tubules of instrumented and retreated root canal surface of split human teeth. Sixty intact extracted human single-rooted teeth were divided into 4 groups, negative control, positive control without canal instrumentation, instrumented, and retreated. Root canals in the instrumented group were enlarged with endodontic instruments, while root canals in the retreated group were enlarged, filled, and then removed the canal filling materials. The teeth were split longitudinally after canal preparation in 3 groups except the negative control group. The teeth were inoculated with both microorganisms separately and in combination. Teeth specimens were examined by scanning electron microscopy (SEM), and the depth of penetration into the dentinal tubules was assessed using the SMILE view software (JEOL Ltd). Penetration of C. albicans and E. faecalis into the dentinal tubules was observed in all 3 groups, although penetration was partially restricted by dentin debris of tubules in the instrumented group and remnants of canal filling materials in the retreated group. In all 3 groups, E. faecalis penetrated deeper into the dentinal tubules by way of cell division than C. albicans which built colonies and penetrated by means of hyphae. Microorganisms can easily penetrate dentinal tubules of root canals with different appearance based on the microorganism size and status of dentinal tubules.

Micro-computed tomography evaluation of the removal of calcium hydroxide medicament from C-shaped root canals of mandibular second molars.

PubMed

Ma, J Z; Shen, Y; Al-Ashaw, A J; Khaleel, H Y; Yang, Y; Wang, Z J; Peng, B; Haapasalo, M

2015-04-01

To use micro-computed tomography (μ-CT) to evaluate the amount of calcium hydroxide [Ca(OH)2 ] remaining in the C-shaped root canals of mandibular second molars after attempting to remove it with passive ultrasonic and sonic irrigation. Thirty mandibular second molars, 15 in C1 and 15 in C2 configurations as first identified by μ-CT, were divided into three groups (five C1 and five C2 in each group) for the three irrigation methods. All teeth were prepared to ProTaper Universal F2 and filled with Ca(OH)2 paste. The Ca(OH)2 was removed with F2 files and irrigation without agitation or with agitation using either EndoActivator or ultrasonics. μ-CT was used to measure the initial amount of Ca(OH)2 present. After removal of Ca(OH)2, μ-CT imaging was used to assess the percentage of volume of residual Ca(OH)2 in the canal. Data were analysed using one-way anova test. There was no significant difference in the mean volume of the root canal systems after instrumentation amongst the three groups. The three irrigation techniques left 2-17% of Ca(OH)2 in the root canals after removal. The mean volume of the remaining Ca(OH)2 was higher in the group without agitation than in the groups with sonic or ultrasonic agitation (P < 0.05). In the apical third, 68% of the canal space remained occupied by Ca(OH)2 when no agitation was used, whereas 28% and 31% remained filled by Ca(OH)2 in the EndoActivator and ultrasonic groups, respectively. There was no significant difference in the amount of residual Ca(OH)2 between the EndoActivator and ultrasonic groups. The proportion of remaining Ca(OH)2 in the apical canals was higher than in the middle and coronal canals in all groups (P < 0.05). A considerable proportion of the apical canal space remained filled with Ca(OH)2 in the C-shaped root canals after instrumentation and conventional needle irrigation. Although combining rotary instrumentation and irrigation with sonic or ultrasonic agitation reduced the amount of residual Ca(OH)2 in the C-shaped root canals, the large amount of calcium hydroxide in the critical apical area remains a concern. Alternative strategies should be considered in medication of the apical canal in C-shaped teeth. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Evaluation of odontological assistance to soldiers going on a mission, and prognostication of their odontological problems.

PubMed

Kelbauskiene, Nijole; Kelbauskas, Eduardas; Nedzelskiene, Irena

2006-01-01

The aim of the study was to evaluate the condition of the oral cavity in soldiers going on a military mission, the level of odontological assistance to them, and to prognosticate possible odontological problems during the mission period. We studied 50 soldiers going on a military mission in Iraq. During the study we applied odontological examination and panoramic imaging. We found that soldiers' teeth were treated, and they received comprehensive odontological assistance: 18% of soldiers had their teeth restored with single crowns and bridges, and 56% of soldiers had underwent endodontic treatment of their teeth. During the radiological examination we diagnosed individual cases of dental caries on the contact surfaces of teeth, and determined the level of the filling of root canals of endodontically treated teeth and the relationship of this level with radiological changes in apical periodontium. 67.3% of teeth had incompletely filled root canals, and radiological changes in their apical periodontium were reliably more frequent (80.6%) than in the apical periodontium of teeth with completely filled root canals (19.4%) (p<0.001). Of significant concern is the fact that frequently teeth with incompletely filled root canals and apical periodontal damage are restored using radical post-core and crowns. Radiological examination showed that in teeth with signs of chronic apical periodontitis and insufficient quality of filling, the condition may become more acute and cause odontological problems. A part of odontological problems in soldiers may be caused by incorrect position of the third molars in the jaw and possible aggravated eruption of these teeth.

Long-Term Fracture Resistance of Simulated Immature Teeth Filled with Various Calcium Silicate-Based Materials.

PubMed

Guven, Yeliz; Tuna, Elif Bahar; Dincol, M Emir; Ozel, Emre; Yilmaz, Bulent; Aktoren, Oya

2016-01-01

Objective. The aim of this in vitro study was to evaluate the long-term fracture resistance of simulated human immature permanent teeth filled with BioAggregate™ (BA), mineral trioxide aggregate (MTA), and EndoSequence® Root Repair Material (ERRM). Material and Methods. 40 teeth, simulated to average root length of 13 ± 1 mm (Cvek's stage 3), were included in the study. The teeth were randomly divided into four groups: Group 1: DiaRoot® BA, Group 2: MTA-Plus™ (MTA-P), Group 3: MTA-Angelus (MTA-A), and Group 4: ERRM. The root canal filling materials were applied according to the manufacturers' instructions. After 24 months of incubation, the roots of the teeth were embedded in acrylic blocks and subjected to fracture testing. The resultant data were analyzed statistically by Kruskal-Wallis and Mann-Whitney U tests. Results. Mean (±SD) failure loads (MPa) were 20.46 ± 2.53 for BA, 18.88 ± 5.13 for MTA-P, 14.12 ± 1.99 for MTA-A, and 17.65 ± 4.28 for ERRM groups. BA group exhibited the highest and MTA-A group showed the lowest resistance to fracture. Significant differences in fracture resistance were found between the groups of BA and MTA-A (p < 0.001), MTA-P and MTA-A (p < 0.05), and ERRM and MTA-A (p < 0.05). Conclusion. Within the limitations of this study, data suggests that BA-filled immature teeth demonstrate higher fracture resistance than other groups at 24 months appearing to be the most promising material tested.

Sealing ability, marginal adaptation and their correlation using three root-end filling materials as apical plugs

PubMed Central

OROSCO, Fernando Accorsi; BRAMANTE, Clovis Monteiro; GARCIA, Roberto Brandão; BERNARDINELI, Norberti; de MORAES, Ivaldo Gomes

2010-01-01

Objective This study used dye leakage assay and scanning electron microscopy to evaluate, respectively, the sealing ability and marginal adaptation of three root-end filling materials used as apical plugs, as well as the possible correlation between these properties. Material and Methods Ninety-eight single-rooted human teeth were prepared to simulate an open apex. The teeth were allocated to three experimental groups (n = 30), which received a 5-mm thick apical plug of (1) gray MTA AngelusTM, (2) CPMTM and (3) MBPc, and two controls groups (n = 4). After immersion in 0.2% Rhodamine B solution for 48 h, the teeth were sectioned longitudinally and analyzed by Image Tool 3.0 software. The marginal adaptation between apical plugs and the root canal walls were analyzed by SEM. Results MBPc had significantly less (p<0.05) apical leakage than the other materials. Regarding marginal adaptation, CPMTM showed the best numerical results, though without statistical significance from the other materials (p<0.05). There was no correlation between the two properties. Conclusions When used as apical plugs, the tested root-end filling materials had similar marginal adaptation to the dentin walls, but MBPc had the best sealing ability, as demonstrated by the least apical leakage from all tested materials. PMID:20485923

Differential diagnosis of endodontic-related inferior alveolar nerve paraesthesia with cone beam computed tomography: a case report.

PubMed

Gambarini, G; Plotino, G; Grande, N M; Testarelli, L; Prencipe, M; Messineo, D; Fratini, L; D'Ambrosio, F

2011-02-01

To discuss the use of cone-beam computed tomography (CBCT) in the differential diagnosis of a case of labiomandibular paraesthesia caused by extrusion of endodontic sealer into the mandibular canal. A 59-year-old woman suffering from a paraesthesia on the left posterior mandible and numbness on the left side of the lower lip was referred to an endodontic specialist 1 month after multiple root canal treatments. A panoramic radiograph revealed the presence of extruded root filling material beyond the apex of the mesial root of the mandibular left second molar and also beyond the apex of the first premolar. A cone beam computed tomography examination was undertaken, which confirmed the presence of radiopaque root canal filling material in the periapical area of the second molar, and revealed that the material was inside the mandibular canal. No extruded filling material was found inside the mental foramen beyond the apex of the first premolar tooth. Small field of view CBCT (where possible) can be considered an effective radiographic diagnostic device when endodontic-related inferior alveolar nerve or mental foramen paraesthesia are suspected. CBCT is able to provide detailed three-dimensional images of the tooth, the root canal system and the surrounding tissue. © 2010 International Endodontic Journal.

Evaluation of subcutaneous and alveolar implantation surgical sites in the study of the biological properties of root-end filling endodontic materials

PubMed Central

CINTRA, Luciano Tavares Angelo; BERNABÉ, Pedro Felício Estrada; de MORAES, Ivaldo Gomes; GOMES-FILHO, João Eduardo; OKAMOTO, Tetuo; CONSOLARO, Alberto; PINHEIRO, Tiago Novaes

2010-01-01

Objective The aim of this study was to compare two methodologies used in the evaluation of tissue response to root-end filling materials in rats. Material and Methods Forty rats were divided into 4 groups: in Groups I and II (control groups), empty polyethylene tubes were implanted in the extraction site and in the subcutaneous tissue, respectively; in Groups III and IV, polyethylene tubes filled with ProRoot MTA were implanted in the extraction site and in the subcutaneous tissue, respectively. The animals were killed 7 and 30 days after tube implantation, and the hemi-maxillas and the capsular subcutaneous tissue, both with the tubes, were removed. Specimens were processed and evaluated histomorphologicaly under light microscopy. The scores obtained were analyzed statistically by the Kruskal-Wallis test (p<0.05). Results There were no statistically significant differences between the implantation methods (p=0.78033, p=0.72039). It was observed that the 30-day groups presented a more mature healing process due to smaller number of inflammatory cells. Conclusion The present study showed no differences in tissue responses as far as the implantation site and the studied period were concerned. Alveolar socket implantation methodology represents an interesting method in the study of the biological properties of root-end filling endodontic materials due to the opportunity to evaluate bone tissue response. PMID:20379685

Deep rooting conferred by DEEPER ROOTING 1 enhances rice yield in paddy fields.

PubMed

Arai-Sanoh, Yumiko; Takai, Toshiyuki; Yoshinaga, Satoshi; Nakano, Hiroshi; Kojima, Mikiko; Sakakibara, Hitoshi; Kondo, Motohiko; Uga, Yusaku

2014-07-03

To clarify the effect of deep rooting on grain yield in rice (Oryza sativa L.) in an irrigated paddy field with or without fertilizer, we used the shallow-rooting IR64 and the deep-rooting Dro1-NIL (a near-isogenic line homozygous for the Kinandang Patong allele of DEEPER ROOTING 1 (DRO1) in the IR64 genetic background). Although total root length was similar in both lines, more roots were distributed within the lower soil layer of the paddy field in Dro1-NIL than in IR64, irrespective of fertilizer treatment. At maturity, Dro1-NIL showed approximately 10% higher grain yield than IR64, irrespective of fertilizer treatment. Higher grain yield of Dro1-NIL was mainly due to the increased 1000-kernel weight and increased percentage of ripened grains, which resulted in a higher harvest index. After heading, the uptake of nitrogen from soil and leaf nitrogen concentration were higher in Dro1-NIL than in IR64. At the mid-grain-filling stage, Dro1-NIL maintained higher cytokinin fluxes from roots to shoots than IR64. These results suggest that deep rooting by DRO1 enhances nitrogen uptake and cytokinin fluxes at late stages, resulting in better grain filling in Dro1-NIL in a paddy field in this study.

Efficacy of Needle, Ultrasonic, and Endoactivator Irrigation and Photon-Induced Photoacoustic Streaming in Removing Calcium Hydroxide from the Main Canal and Isthmus: An In Vitro Micro-Computed Tomography and Scanning Electron Microscopy Study.

PubMed

Li, Dongxia; Jiang, Shan; Yin, Xingzhe; Chang, Jeffrey Wen Wei; Ke, Jie; Zhang, Chengfei

2015-06-01

The aim of this in vitro study was to use high-resolution micro-computed tomography (micro-CT) and scanning electron microscopy (SEM) to compare the efficacy of four irrigation techniques [needle, ultrasonic, EndoActivator, and photon-induced photoacoustic streaming (PIPS)] in removing calcium hydroxide (Ca[OH]2) from the root canal and isthmus of maxillary premolars. Twenty-four maxillary first premolars were selected based on the presence of isthmus regions on micro-CT scans. Root canals were instrumented with an F2 file using ProTaper rotary instruments and filled with Ca(OH)2 paste. Samples were stored at 37°C and 100% humidity for 1 week and randomly divided into four groups (n=6 each), according to irrigation technique. Samples were scanned with micro-CT before instrumentation, after Ca(OH)2 filling, and after irrigation. Ca(OH)2 reduction in the coronal, middle, and apical thirds and in the isthmus were assessed with three-dimensional image analysis. Next, specimens were split longitudinally, and canal walls were examined with SEM for Ca(OH)2 residues. Data were statistically evaluated with the Kruskal-Wallis and Mann-Whitney tests (p=0.05). The PIPS and ultrasonic groups showed greater Ca(OH)2 reduction in the apical third and higher cleanliness of the isthmus than the EndoActivator and needle irrigation groups (p<0.05). Ca(OH)2 residue scores in the PIPS and ultrasonic groups were significantly lower than those in the EndoActivator and needle groups in all regions of the root canals (p<0.05). There was no significant difference between PIPS and ultrasonic groups (p>0.05), or between EndoActivator and needle groups (p>0.05). PIPS and ultrasonic irrigation more effectively removed Ca(OH)2 from the main canal and isthmus in maxillary premolars than did EndoActivator or needle irrigation.

Root canal preparation in endodontics: conventional versus laser methods

NASA Astrophysics Data System (ADS)

Goodis, Harold E.; White, Joel M.; Marshall, Sally J.; Marshall, Grayson W.; Moskowitz, Emrey

1992-06-01

Conventional cleaning and shaping of root canal systems employs hand and/or rotary instrumentation to remove the contents of the canal and shape the canal to receive a filling material. With the advent of the Nd:YAG laser system another method of accomplishing proper cleaning and shaping is evaluated. Single rooted teeth were radiographed bucco- lingually and mesio-distally and were divided into 2 groups. The first group was accessed and the root canal systems cleaned and shaped with a step back technique utilizing hand files and gates glidden burs. At completion of the procedure the teeth were again radiographed at the same positions as those prior to the procedure. The teeth were split longitudinally and examined under scanning electron microscopy to assess cleaning. The second group of teeth were accessed, and cleaning and shaping was accomplished using the Nd:YAG laser in combination with hand files and rotary instruments. These teeth were subjected to the same analysis as those in the first group. The before and after radiographs of each group were subjected to image analysis to determine effectiveness of the two methods in shaping the canal systems. We will discuss the ability of Nd:YAG to clean and shape root canal spaces and remove smear layer and organic tissue remnants from those areas.

Healing process following application of set or fresh mineral trioxide aggregate as a root-end filling material.

PubMed

Habibi, Mehdi; Ghoddusi, Jamileh; Habibi, Ataollah; Mohtasham, Nooshin

2011-01-01

An unsuccessful attempt to reach the apical area or to place the retrograde material is a major difficulty in periradicular surgery. The aim of this study was to compare the histological evaluation of the healing process following an orthograde versus a retrograde application of mineral trioxide aggregate (MTA) as a root-end filling material during apical surgery on cats' teeth in order to find out whether orthograde placement of MTA before surgery can be used instead of retrograde placement during surgery. In this experimental study, 24 canine teeth in 12 mature and healthy cats were filled with either MTA or gutta-percha in an orthograde manner. Two weeks later, the teeth with MTA were surgically exposed and resected to the set-MTA within the canals. The teeth previously filled by gutta-percha were also surgically exposed, and retrograde cavities were prepared at the root ends and filled with fresh-MTA. After 8 weeks, the animals were euthanized by vital perfusion. Six-micron histological slices were prepared from samples, stained by Hematoxylin & Eosin, and histologically studied by means of a light microscope. The collected data was analyzed by the Chi-square and the T-test. One of the samples in the fresh-MTA group was omitted during processing because of inappropriate sectioning. In the set-MTA group, 5 out of 12 showed chronic abscess, while in the fresh-MTA group, 2 out of 11 were discovered to have chronic abscess; however, no significant difference was observed (P>.05). Hard tissue healing (cementum, bone, cementum + bone formation) in the set-MTA and fresh-MTA groups were 7 out of 12 and 9 out of 11, respectively. While healing seemed more likely to occur in the fresh-MTA group, the difference was statistically insignificant (P>.05). The magnitude of bone, cementum, or bone and cementum formation showed slight differences between the two groups; however, the figures failed to show any marked differences (P>.05). Orthograde placement of MTA could be used as an obturation material before surgery. In this way, after root-end resection, there would be no need for root-end preparation and filling procedures.

Prevalence of apical periodontitis and endodontic treatment in a Kosovar adult population.

PubMed

Kamberi, Blerim; Hoxha, Veton; Stavileci, Miranda; Dragusha, Edmond; Kuçi, Astrit; Kqiku, Lumnije

2011-11-29

Despite numerous studies on the prevalence of apical periodontitis (AP) and endodontic treatment in diverse geographical populations, there are currently no data on the prevalence of these conditions in populations of adults native to Kosovo. Therefore, little is known about how widespread these conditions are, and whether there is any correlation between root canal treatment and AP. The purpose of our research was to address this anomaly by investigating AP and endodontic treatment in an adult Kosovar population based on radiographic examination. The sample used for this study consisted of randomly selected individuals referred to the University Dentistry Clinical Center of Kosovo in the years 2006-2007. Orthopantomographs of 193 patients were evaluated. The periapical status of all teeth (with the exception of third molars) was examined according to Ørstavik's Periapical Index. The quality of the root canal filling was rated as 'adequate' or 'inadequate' based on whether all canals were filled, the depth of fill relative to the radiographic apex and the quality of compaction (absence/presence of voids). Data were analyzed statistically using the Chi-square test and calculation of odds ratios. Out of 4131 examined teeth, the prevalence of apical periodontitis (AP) and endodontic treatment was 12.3% and 2.3%, respectively. Of 95 endodontically-treated teeth, 46.3% were associated with AP. The prevalence of AP increased with age. The prevalence in subjects aged over 60 years old (20.2%) was higher than in other age groups. A statistically significant difference was found for the frequency of endodontically-treated teeth associated with AP in the 40-49 year age group (P < 0.001). Of some concern was the discovery that only 30.5% of the endodontically-treated teeth examined met the criteria of an acceptable root canal filling. Inadequately root-filled teeth were associated with an increased AP risk. The prevalence of AP and the frequency of endodontically-treated teeth with AP in this Kosovar population are higher than those found in other countries. Inadequate root canal fillings were associated with an increased prevalence of AP.

Effect of the size of the apical enlargement with rotary instruments, single-cone filling, post space preparation with drills, fiber post removal, and root canal filling removal on apical crack initiation and propagation.

PubMed

Çapar, İsmail Davut; Uysal, Banu; Ok, Evren; Arslan, Hakan

2015-02-01

The purpose of this study was to investigate the incidence of apical crack initiation and propagation in root dentin after several endodontic procedures. Sixty intact mandibular premolars were sectioned perpendicular to the long axis at 1 mm from the apex, and the apical surface was polished. Thirty teeth were left unprepared and served as a control, and the remaining 30 teeth were instrumented with ProTaper Universal instruments (Dentsply Maillefer, Ballaigues, Switzerland) up to size F5. The root canals were filled with the single-cone technique. Gutta-percha was removed with drills of the Rebilda post system (VOCO, Cuxhaven, Germany). Glass fiber-reinforced composite fiber posts were cemented using a dual-cure resin cement. The fiber posts were removed with a drill of the post system. Retreatment was completed after the removal of the gutta-percha. Crack initiation and propagation in the apical surfaces of the samples were examined with a stereomicroscope after each procedure. The absence/presence of cracks was recorded. Logistic regression was performed to analyze statistically the incidence of crack initiation and propagation with each procedure. The initiation of the first crack and crack propagation was associated with F2 and F4 instruments, respectively. The logistic regression analysis revealed that instrumentation and F2 instrument significantly affected apical crack initiation (P < .001). Post space preparation had a significant effect on crack propagation (P = .0004). The other procedures had no significant effects on crack initiation and propagation (P > .05). Rotary nickel-titanium instrumentation had a significant effect on apical crack initiation, and post space preparation with drills had a significant impact on crack propagation. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Influence of 2% chlorhexidine on pH, calcium release and setting time of a resinous MTA-based root-end filling material.

PubMed

Jacinto, Rogério Castilho; Linhares-Farina, Giane; Sposito, Otávio da Silva; Zanchi, César Henrique; Cenci, Maximiliano Sérgio

2015-01-01

The addition of chlorhexidine (CHX) to a resinous experimental Mineral Trioxide Aggregate (E-MTA) based root-end filling material is an alternative to boost its antimicrobial activity. However, the influence of chlorhexidine on the properties of this material is unclear. The aim of this study was to evaluate the influence of 2% chlorhexidine on the pH, calcium ion release and setting time of a Bisphenol A Ethoxylate Dimethacrylate/Mineral Trioxide Aggregate (Bis-EMA/MTA) based dual-cure experimental root-end filling material (E-MTA), in comparison with E-MTA without the addition of CHX and with conventional white MTA (W-MTA). The materials were placed in polyethylene tubes, and immersed in deionized water to determine pH (digital pH meter) and calcium ion release (atomic absorption spectrometry technique). The setting time of each material was analyzed using Gilmore needles. The data were statistically analyzed at a significance level of 5%. E-MTA + CHX showed an alkaline pH in the 3 h period of evaluation, the alkalinity of which decreased but remained as such for 15 days. The pH of E-MTA + CHX was higher than the other two materials after 7 days, and lower after 30 days (p < 0.05). All of the materials were found to release calcium ions throughout the 30 days of the study. The addition of CHX increased the calcium ion release of E-MTA to levels statistically similar to W-MTA. E-MTA showed shorter initial and final setting time, compared with W-MTA (p < 0.05). The addition of 2% CHX to MTA prevented setting of the material. The addition of CHX to E-MTA increased its pH and calcium ion release. However, it also prevented setting of the material.

Incidence of apical crack initiation and propagation during the removal of root canal filling material with ProTaper and Mtwo rotary nickel-titanium retreatment instruments and hand files.

PubMed

Topçuoğlu, Hüseyin Sinan; Düzgün, Salih; Kesim, Bertan; Tuncay, Oznur

2014-07-01

The aim of this study was to determine the incidence of crack initiation and propagation in apical root dentin after retreatment procedures performed by using 2 rotary retreatment systems and hand files with additional instrumentation. Eighty extracted mandibular premolars with single canals were selected. One millimeter from the apex of each tooth was ground perpendicular to the long axis of the tooth, and the apical surface was polished. Twenty teeth served as the control group, and no preparation was performed. The remaining 60 teeth were prepared to size 35 with rotary files and filled with gutta-percha and AH Plus sealer. Specimens were then divided into 3 groups (n = 20), and retreatment procedures were performed with the following devices and techniques: ProTaper Universal retreatment files, Mtwo retreatment files, and hand files. After retreatment, the additional instrumentation was performed by using size 40 ProTaper, Mtwo, and hand files. Digital images of the apical root surface were recorded before preparation, after instrumentation, after filling, after retreatment, and after additional instrumentation. The images were then inspected for the presence of any new apical cracks and propagation. Data were analyzed with the logistic regression and Fisher exact tests. All experimental groups caused crack initiation and propagation after use of retreatment instruments. The ProTaper and Mtwo retreatment groups caused greater crack initiation and propagation than the hand instrument group (P < .05) after retreatment. Additional instrumentation with ProTaper and Mtwo instruments after the use of retreatment instruments caused crack initiation and propagation, whereas hand files caused neither crack initiation nor propagation (P < .05). This study showed that retreatment procedures and additional instrumentation after the use of retreatment files may cause crack initiation and propagation in apical dentin. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Rooting traits of peanut genotypes with different yield responses to terminal drought

USDA-ARS?s Scientific Manuscript database

Drought at pod filling can severely reduce yield of peanut. Better root systems can reduce yield loss from drought. However, the relationship of root characters with yield under terminal drought is not well understood. The objective of this study was to investigate the responses of peanut genotyp...

Efficacy of D-RaCe and ProTaper Universal Retreatment NiTi instruments and hand files in removing gutta-percha from curved root canals - a micro-computed tomography study.

PubMed

Rödig, T; Hausdörfer, T; Konietschke, F; Dullin, C; Hahn, W; Hülsmann, M

2012-06-01

To compare the efficacy of two rotary NiTi retreatment systems and Hedström files in removing filling material from curved root canals. Curved root canals of 57 extracted teeth were prepared using FlexMaster instruments and filled with gutta-percha and AH Plus. After determination of root canal curvatures and radii in two directions, the teeth were assigned to three identical groups (n = 19). The root fillings were removed with D-RaCe instruments, ProTaper Universal Retreatment instruments or Hedström files. Pre- and postoperative micro-CT imaging was used to assess the percentage of residual filling material as well as the amount of dentine removal. Working time and procedural errors were recorded. Data were analysed using analysis of covariance and analysis of variance procedures. D-RaCe instruments were significantly more effective than ProTaper Universal Retreatment instruments and Hedström files (P < 0.05). Hedström files removed significantly less dentine than the rotary NiTi systems (P < 0.0001). D-RaCe instruments were significantly faster compared to both other groups (P < 0.05). No procedural errors such as instrument fracture, blockage, ledging or perforation were detected in the Hedström group. In the ProTaper group, four instrument fractures and one lateral perforation were observed. Five instrument fractures were recorded for D-RaCe. D-RaCe instruments were associated with significantly less residual filling material than ProTaper Universal Retreatment instruments and hand files. Hedström files removed significantly less dentine than both rotary NiTi systems. Retreatment with rotary NiTi systems resulted in a high incidence of procedural errors. © 2012 International Endodontic Journal.

Endodontic treatment of mandibular molar with root dilaceration using Reciproc single-file system.

PubMed

Meireles, Daniely Amorin; Bastos, Mariana Mena Barreto; Marques, André Augusto Franco; Garcia, Lucas da Fonseca Roberti; Sponchiado, Emílio Carlos

2013-08-01

Biomechanical preparation of root canals with accentuated curvature is challenging. New rotatory systems, such as Reciproc, require a shorter period of time to prepare curved canals, and became a viable alternative for endodontic treatment of teeth with root dilaceration. Thus, this study aimed to report a clinical case of endodontic therapy of root with accentuated dilaceration using Reciproc single-file system. Mandibular right second molar was diagnosed as asymptomatic irreversible pulpitis. Pulp chamber access was performed, and glide path was created with #10 K-file (Dentsply Maillefer) and PathFile #13, #16 and #19 (Dentsply Maillefer) up to the temporary working length. The working length measured corresponded to 20 mm in the mesio-buccal and mesio-lingual canals, and 22 mm in the distal canal. The R25 file (VDW GmbH) was used in all the canals for instrumentation and final preparation, followed by filling with Reciproc gutta-percha cones (VDW GmbH) and AH Plus sealer (Dentsply Maillefer), using thermal compaction technique. The case has been receiving follow-up for 6 mon and no painful symptomatology or periapical lesions have been found. Despite the difficulties, the treatment could be performed in a shorter period of time than the conventional methods.

A review of the regenerative endodontic treatment procedure

PubMed Central

Lee, Bin-Na; Moon, Jong-Wook; Chang, Hoon-Sang; Hwang, In-Nam; Oh, Won-Mann

2015-01-01

Traditionally, apexification has been used to treat immature permanent teeth that have lost pulp vitality. This technique promotes the formation of an apical barrier to close the open apex so that the filling materials can be confined to the root canal. Because tissue regeneration cannot be achieved with apexification, a new technique called regenerative endodontic treatment was presented recently to treat immature permanent teeth. Regenerative endodontic treatment is a treatment procedure designed to replace damaged pulp tissue with viable tissue which restores the normal function of the pulp-dentin structure. After regenerative endodontic treatment, continued root development and hard tissue deposition on the dentinal wall can occur under ideal circumstances. However, it is difficult to predict the result of regenerative endodontic treatment. Therefore, the purpose of this study was to summarize multiple factors effects on the result of regenerative endodontic treatment in order to achieve more predictable results. In this study, we investigated the features of regenerative endodontic treatment in comparison with those of other pulp treatment procedures and analyzed the factors that have an effect on regenerative endodontic treatment. PMID:26295020

Microorganism penetration in dentinal tubules of instrumented and retreated root canal walls. In vitro SEM study

PubMed Central

Al-Sulaiman, Alaa; Al-Rasheed, Fellwa; Alnajjar, Fatimah; Al-Abdulwahab, Bander; Al-Badah, Abdulhakeem

2014-01-01

Objectives This in vitro study aimed to investigate the ability of Candida albicans (C. albicans) and Enterococcus faecalis (E. faecalis) to penetrate dentinal tubules of instrumented and retreated root canal surface of split human teeth. Materials and Methods Sixty intact extracted human single-rooted teeth were divided into 4 groups, negative control, positive control without canal instrumentation, instrumented, and retreated. Root canals in the instrumented group were enlarged with endodontic instruments, while root canals in the retreated group were enlarged, filled, and then removed the canal filling materials. The teeth were split longitudinally after canal preparation in 3 groups except the negative control group. The teeth were inoculated with both microorganisms separately and in combination. Teeth specimens were examined by scanning electron microscopy (SEM), and the depth of penetration into the dentinal tubules was assessed using the SMILE view software (JEOL Ltd). Results Penetration of C. albicans and E. faecalis into the dentinal tubules was observed in all 3 groups, although penetration was partially restricted by dentin debris of tubules in the instrumented group and remnants of canal filling materials in the retreated group. In all 3 groups, E. faecalis penetrated deeper into the dentinal tubules by way of cell division than C. albicans which built colonies and penetrated by means of hyphae. Conclusions Microorganisms can easily penetrate dentinal tubules of root canals with different appearance based on the microorganism size and status of dentinal tubules. PMID:25383343

Critical review on methacrylate resin-based root canal sealers.

PubMed

Kim, Young Kyung; Grandini, Simone; Ames, Jason M; Gu, Li-sha; Kim, Sung Kyo; Pashley, David H; Gutmann, James L; Tay, Franklin R

2010-03-01

Four generations of methacrylate resin-based sealers have been available commercially. Three of these were introduced during the last 5 years when the concept of simultaneous bonding of root canal sealers to root filling materials and dentin was popularized. This article presents an overview of methacrylate resin-based sealers, with the objectives of clarifying the behavior of these materials and delineating their limitations in clinical application. The first generation sealer was introduced in the mid-1970s. The initial enthusiasm associated with its use eventually diminished as a result of its suboptimal physical, biologic, and clinical properties. With advances in self-etching adhesive technology acquired from adhesive dentistry, methacrylate resin-based sealers were reintroduced in the beginning of the 21st century to support the introduction of bondable root canal filling materials. Three different generations of these sealers have since been available commercially. Although some in vitro studies on the sealing ability, self-etching potential, biocompatibility, and removability of the sealers showed better potential over conventional nonbonding sealers, accomplishing the ideal goal of a monoblock in the root canal space with these materials is still regarded as a major challenge. On the basis of the in vitro and in vivo data available to date, there appears to be no clear benefit with the use of methacrylate resin-based sealers in conjunction with adhesive root filling materials at this point in their development. Copyright (c) 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

FEM analysis of different dental root canal-post systems in young permanent teeth.

PubMed

Vitale, M C; Chiesa, M; Coltellaro, F; Bignardi, C; Celozzi, M; Poggio, C

2008-09-01

Aim of this work was to carry out a comparative evaluation of the structural behaviour of different root canal posts (cylindrical, conical and triple conical) fitted in a second lower bicuspid and subjected to compression and bending test. This study has been carried out by numerical method of structural analysis of finite elements (FEM, Finite Element Method). Different tridimensional models were obtained by CAT images of an extracted tooth, endodontically treated, filled with guttapercha and triple conical glass post. Images have been elaborated by a software for images (Mimics and Ansys) and CAD (Rhinoceros 3 D). In the models a II Class restoration has been virtually created. In the numerical simulation dental tissues (enamel, dentine and root cement), guttapercha, root canal cement, different posts, different techniques of cementation and crown restoration (composites and adhesive systems) have been considered. Strain distributions in dental tissues, in root canal cement and in posts have been compared. The equivalent tensions and the single components (traction, compression and cut) have been analysed. In all examined posts, the most strained part is resulted the coronal one, even if the total tension, in the different tooth-post analyzed systems, resulted uniformly distributed. A similar behaviour was shown by the root canal cement. According to the analyzed conditions of bond and load, varying according to the geometry of the considered posts, our results confirm that there is no substantial difference of deformation in posts, root canal cement and treated tooth.

Anatomical analysis of the resected roots of mandibular first molars after failed non-surgical retreatment

PubMed Central

2018-01-01

Objectives Understanding the reason for an unsuccessful non-surgical endodontic treatment outcome, as well as the complex anatomy of the root canal system, is very important. This study examined the cross-sectional root canal structure of mandibular first molars confirmed to have failed non-surgical root canal treatment using digital images obtained during intentional replantation surgery, as well as the causative factors of the failed conventional endodontic treatments. Materials and Methods This study evaluated 115 mandibular first molars. Digital photographic images of the resected surface were taken at the apical 3 mm level and examined. The discolored dentin area around the root canal was investigated by measuring the total surface area, the treated areas as determined by the endodontic filling material, and the discolored dentin area. Results Forty 2-rooted teeth showed discolored root dentin in both the mesial and distal roots. Compared to the original filled area, significant expansion of root dentin discoloration was observed. Moreover, the mesial roots were significantly more discolored than the distal roots. Of the 115 molars, 92 had 2 roots. Among the mesial roots of the 2-rooted teeth, 95.7% of the roots had 2 canals and 79.4% had partial/complete isthmuses and/or accessory canals. Conclusions Dentin discoloration that was not visible on periapical radiographs and cone-beam computed tomography was frequently found in mandibular first molars that failed endodontic treatment. The complex anatomy of the mesial roots of the mandibular first molars is another reason for the failure of conventional endodontic treatment. PMID:29765897

Intentional Replantation of an Immature Incisor with a Transverse Root Fracture and Endo-Perio Condition: 4 Year Follow-Up.

PubMed

Oishi, Atsushi

This case report describes the importance of continual examination for dental trauma and the efficacy of intentional replantation with retrograde root canal filling for a transverse root fracture in an immature incisor accompanied by subsequent periodontal-endodontic disease. In the treatment of traumatically fractured roots in immature incisors, continual examination is indispensable for the final diagnosis because roots in immature teeth are less calcified, resulting in less detailed radiological examinations. Thus, common dental trauma complications such as pulp necrosis may appear months after the initial examination. Endodontic treatment for transverse root fracture is mainly determined according to radiographic examination findings; for fractured immature roots, apexification with calcium hydroxide of the coronal fragment is generally applied. However, this method requires removal of considerable amounts of enamel and dentin to allow access to the cavity for preparation, which may increase the risk of future fractures. In contrast, intentional replantation with retrograde root canal filling does not require the removal or long-term application of calcium hydroxide. However, it requires careful extraction of the tooth, maintenance of root wetness during the extraoral procedure, rigid splinting, and oral hygiene control. Management of tooth mobility is also important in the post-replantation course.

Evaluation of physicochemical properties of root-end filling materials using conventional and Micro-CT tests

PubMed Central

TORRES, Fernanda Ferrari Esteves; BOSSO-MARTELO, Roberta; ESPIR, Camila Galletti; CIRELLI, Joni Augusto; GUERREIRO-TANOMARU, Juliane Maria; TANOMARU-FILHO, Mario

2017-01-01

Abstract Objective To evaluate solubility, dimensional stability, filling ability and volumetric change of root-end filling materials using conventional tests and new Micro-CT-based methods. Material and Methods 7 Results The results suggested correlated or complementary data between the proposed tests. At 7 days, BIO showed higher solubility and at 30 days, showed higher volumetric change in comparison with MTA (p<0.05). With regard to volumetric change, the tested materials were similar (p>0.05) at 7 days. At 30 days, they presented similar solubility. BIO and MTA showed higher dimensional stability than ZOE (p<0.05). ZOE and BIO showed higher filling ability (p<0.05). Conclusions ZOE presented a higher dimensional change, and BIO had greater solubility after 7 days. BIO presented filling ability and dimensional stability, but greater volumetric change than MTA after 30 days. Micro-CT can provide important data on the physicochemical properties of materials complementing conventional tests. PMID:28877275

Advances in endodontics: Potential applications in clinical practice

PubMed Central

Kishen, Anil; Peters, Ove A.; Zehnder, Matthias; Diogenes, Anibal R.; Nair, Madhu K.

2016-01-01

Contemporary endodontics has seen an unprecedented advance in technology and materials. This article aimed to review some of the challenges and advances in the following sections: (1) endodontic imaging, (2) root canal preparation, (3) root canal disinfection, (4) root canal filling, and (4) regenerative endodontic procedures (REPs). Jointly, these advances are aimed at improving the state of the art and science of root canal treatment. PMID:27217630

Apical closure of mature molar roots with the use of calcium hydroxide.

PubMed

Rotstein, I; Friedman, S; Katz, J

1990-11-01

Calcium hydroxide may induce apical root closure in affected mature teeth as well as in immature teeth. Once an apical hard tissue barrier is formed, a permanent root canal filling can be safely condensed. Two cases are described in which calcium hydroxide induced apical root closure in mature molar teeth where the apical constriction was lost because of chronic inflammatory process.

A microleakage study of gutta-percha/AH Plus and Resilon/Real self-etch systems after different irrigation protocols.

PubMed

Prado, Maíra; Simão, Renata Antoun; Gomes, Brenda Paula Figueiredo de Almeida

2014-06-01

The development and maintenance of the sealing of the root canal system is the key to the success of root canal treatment. The resin-based adhesive material has the potential to reduce the microleakage of the root canal because of its adhesive properties and penetration into dentinal walls. Moreover, the irrigation protocols may have an influence on the adhesiveness of resin-based sealers to root dentin. The objective of the present study was to evaluate the effect of different irrigant protocols on coronal bacterial microleakage of gutta-percha/AH Plus and Resilon/Real Seal Self-etch systems. One hundred ninety pre-molars were used. The teeth were divided into 18 experimental groups according to the irrigation protocols and filling materials used. The protocols used were: distilled water; sodium hypochlorite (NaOCl)+eDTA; NaOCl+H3PO4; NaOCl+eDTA+chlorhexidine (CHX); NaOCl+H3PO4+CHX; CHX+eDTA; CHX+ H3PO4; CHX+eDTA+CHX and CHX+H3PO4+CHX. Gutta-percha/AH Plus or Resilon/Real Seal Se were used as root-filling materials. The coronal microleakage was evaluated for 90 days against Enterococcus faecalis. Data were statistically analyzed using Kaplan-Meier survival test, Kruskal-Wallis and Mann-Whitney tests. No significant difference was verified in the groups using chlorhexidine or sodium hypochlorite during the chemo-mechanical preparation followed by eDTA or phosphoric acid for smear layer removal. The same results were found for filling materials. However, the statistical analyses revealed that a final flush with 2% chlorhexidine reduced significantly the coronal microleakage. A final flush with 2% chlorhexidine after smear layer removal reduces coronal microleakage of teeth filled with gutta-percha/AH Plus or Resilon/Real Seal SE.

Short-term vs long-term calcium hydroxide therapy after immediate tooth replantation: a histomorphometric study in monkey's teeth.

PubMed

Panzarini, Sônia Regina; Gulinelli, Jéssica Lemos; Saito, Célia T M H; Poi, Wilson Roberto; Sonoda, Celso Koogi; Américo de Oliveira, José; Melo, Moriel Evangelista; de Souza Gomes, Weglis Dyanne

2012-06-01

Endodontic treatment is an important step of tooth replantation protocols, but the ideal moment for definitive obturation of replanted teeth has not yet been established. In this study, a histomorphometric analysis was undertaken to evaluate the repair process on immediate replantation of monkey's teeth after calcium hydroxide (CH) therapy for 1 and 6 months followed by root canal filling with a CH-based sealer (Sealapex(®) ). The maxillary and mandibular lateral incisors of five female Cebus apella monkeys were extracted, kept in sterile saline for 15 min, replanted and splinted with stainless steel orthodontic wire and composite resin for 10 days. In Group I (control), definitive root canal filling was performed before tooth extraction. In Groups II and III, CH therapy started after removal of splint, and definitive root canal filling was performed 1 and 6 months later, respectively. The animals were euthanized 9 months after replantation, and specimens were processed for histomorphometric analysis. In all groups, epithelial attachment occurred at the cementoenamel junction or very close to this region; the areas of resorption on root surface had small extension and depth and were repaired by newly formed cementum; and the periodontal ligament was organized. Statistical analysis of the scores obtained for the histomorphometric parameters did not show any statistically significant difference (P = 0.1221) among the groups. The results suggests that when endodontic treatment is initiated 10 days after immediate replantation and an antibiotic regimen is associated, definitive root canal filling can be performed after a short-term CH therapy. © 2011 John Wiley & Sons A/S.

A Systematic Review of Root Canal Filling Materials for Deciduous Teeth: Is There an Alternative for Zinc Oxide-Eugenol?

PubMed Central

Barja-Fidalgo, Fernanda; Moutinho-Ribeiro, Michele; Oliveira, Maria Angelina Amorim; de Oliveira, Branca Heloísa

2011-01-01

The aim of this systematic review was to determine whether there is a root canal filling for deciduous teeth equally or more effective than zinc oxide-eugenol cement (ZOE). Six clinical trials selected for inclusion were independently reviewed by two researchers. Only two showed statistically significant different success rates between the test and the control groups. One found that an iodoform paste with calcium hydroxide (IP + Ca) performed better than ZOE, and the other found that ZOE performed similarly to IP + Ca. The other four studies compared ZOE with an iodoform paste (IP), a calcium hydroxide cement (Ca(OH)2), or IP + Ca. In these trials, the success rates in the ZOE groups were slightly lower than in the other groups. There seems to be no convincing evidence to support the superiority of any material over ZOE, and both ZOE and IP + Ca appear to be suitable as root canal fillings for deciduous teeth. PMID:21991471

21 CFR 872.3850 - Gutta percha.

Code of Federal Regulations, 2012 CFR

2012-04-01

... made from coagulated sap of certain tropical trees intended to fill the root canal of a tooth. The gutta percha is softened by heat and inserted into the root canal, where it hardens as it cools. (b...

21 CFR 872.3850 - Gutta percha.

Code of Federal Regulations, 2011 CFR

2011-04-01

... made from coagulated sap of certain tropical trees intended to fill the root canal of a tooth. The gutta percha is softened by heat and inserted into the root canal, where it hardens as it cools. (b...

21 CFR 872.3850 - Gutta percha.

Code of Federal Regulations, 2013 CFR

2013-04-01

... made from coagulated sap of certain tropical trees intended to fill the root canal of a tooth. The gutta percha is softened by heat and inserted into the root canal, where it hardens as it cools. (b...

[Theory and practice of minimally invasive endodontics].

PubMed

Jiang, H W

2016-08-01

The primary goal of modern endodontic therapy is to achieve the long-term retention of a functional tooth by preventing or treating pulpitis or apical periodontitis is. The long-term retention of endodontically treated tooth is correlated with the remaining amount of tooth tissue and the quality of the restoration after root canal filling. In recent years, there has been rapid progress and development in the basic research of endodontic biology, instrument and applied materials, making treatment procedures safer, more accurate, and more efficient. Thus, minimally invasive endodontics(MIE)has received increasing attention at present. MIE aims to preserve the maximum of tooth structure during root canal therapy, and the concept covers the whole process of diagnosis and treatment of teeth. This review article focuses on describing the minimally invasive concepts and operating essentials in endodontics, from diagnosis and treatment planning to the access opening, pulp cavity finishing, root canal cleaning and shaping, 3-dimensional root canal filling and restoration after root canal treatment.

Root canal treatment of a periradicular lesion caused by unintentional root damage after orthodontic miniscrew placement: a case report.

PubMed

Er, K; Bayram, M; Taşdemir, T

2011-12-01

To present the successful endodontic management of a maxillary lateral incisor tooth with a periradicular lesion caused by unintentional root damage after orthodontic miniscrew placement. A 22-year-old female was diagnosed with a skeletal Class II, Division 2 malocclusion with Class II molar and canine relationships on both sides. The treatment plan included distalization of the maxillary first molars bilaterally followed by full fixed appliance therapy. For the maxillary molar distalization, an appliance in conjunction with a miniscrew anchorage system was designed. Two months later, the patient came to the clinic with complaints of pain in the maxillary right lateral incisor region. On intraoral examination, intraoral sinus tracts were detected in the maxillary right buccal sulcus and palate. A large radiolucent lesion with a well-defined margin around the root of the maxillary right lateral incisor was seen. Root canal treatment was performed on the maxillary right lateral incisor tooth. The root canal was filled with gutta-percha and AH Plus sealer, using a lateral compaction technique. The final restoration of the tooth was completed using composite, and the tooth was reviewed after 10 months. The tooth was asymptomatic and radiographically showed repair of the lesion. Healing was achieved without any need for further endodontic or surgical intervention. Key learning points • This case illustrates the need to take care with miniscrews when performing orthodontic treatment, especially when the miniscrews are in close proximity to root apices. • The periradicular lesion as a result of miniscrew damage was successfully treated with root canal treatment. © 2011 International Endodontic Journal.

Graviresponsiveness of surgically altered primary roots of Zea mays

NASA Technical Reports Server (NTRS)

Maimon, E.; Moore, R.

1991-01-01

We examined the gravitropic responses of surgically altered primary roots of Zea mays to determine the route by which gravitropic inhibitors move from the root tip to the elongating zone. Horizontally oriented roots, from which a 1-mm-wide girdle of epidermis plus 2-10 layers of cortex were removed from the apex of the elongating zone, curve downward. However, curvature occurred only apical to the girdle. Filling the girdle with mucilage-like material transmits curvature beyond the girdle. Vertically oriented roots with a half-girdle' (i.e. the epidermis and 2-10 layers of the cortex removed from half of the circumference of the apex of the elongating zone) curve away from the girdle. Inserting the half-girdle at the base of the elongating zone induces curvature towards the girdle. Filling the half-circumference girdles with mucilage-like material reduced curvature significantly. Stripping the epidermis and outer 2-5 layers of cortex from the terminal 1.5 cm of one side of a primary root induces curvature towards the cut, irrespective of the root's orientation to gravity. This effect is not due to desiccation since treated roots submerged in water also curved towards their cut surface. Coating a root's cut surface with a mucilage-like substance minimizes curvature. These results suggest that the outer cell-layers of the root, especially the epidermis, play an important role in root gravicurvature, and the gravitropic signals emanating from the root tip can move apoplastically through mucilage.

Evaluation of the sealing ability of gutta-percha and thermoplastic synthetic polymer-based systems along the root canals through the glucose penetration model.

PubMed

Kaya, B Ureyen; Kececi, Ayşe Diljin; Belli, S

2007-12-01

To compare the sealing ability of gutta-percha and thermoplastic synthetic polymer-based systems along the root canals using a recently introduced glucose penetration model. Premolars (n = 156) instrumented to an apical size of .06/40 were divided into 12 experimental and 2 control groups. The root canals were filled with either gutta-percha (groups 1-6) or Resilon (groups 7-12) core materials combined with AH Plus (groups 1, 4, 7, 0), Ketac Endo (groups 1, 5, 8, 11), or Epiphany (groups 2, 6, 9, 12), using cold lateral compaction (groups 1-3, 7-9) or System B with Obtura II (groups 4-6, 10-12). The leaked glucose concentration was measured spectrophotometrically at 1, 8, 15, 22, and 30 days. Percentage leaking of each group was also calculated. Data were recorded as mmol/L and statistically analyzed with Kruskal-Wallis and Mann-Whitney U tests (P = .05). Throughout the experimental period Resilon/Ketac-Endo/cold lateral compaction (group 8) showed the highest mean cumulative glucose penetration (mmol/L) (17.27 +/- 10.32), whereas Resilon/AH Plus/cold lateral compaction (group 7) had the least (3.36 +/- 4.65) (P < .05). At the 30(th) day, the least leaking percentage was observed in gutta-percha, Epiphany/cold lateral compaction (group 3). Glucose penetration was affected by the obturation technique in some groups. Ketac-Endo either with gutta-percha (group 2) or Resilon (group 8) indicated significantly less glucose penetration in warm technique, whereas gutta-percha/Epiphany (group 3) had significantly less glucose penetration in cold technique (P < .05). All material/technique combinations allowed glucose penetration. Gutta-percha/AH Plus combinations allowed similar patterns of glucose penetration to Resilon/Epiphany combinations.

Restricting the above ground sink corrects the root/shoot ratio and substantially boosts the yield potential per panicle in field-grown rice (Oryza sativa L.).

PubMed

Nada, Reham M; Abogadallah, Gaber M

2016-04-01

Rice has shallow, weak roots, but it is unknown how much increase in yield potential could be achieved if the root/shoot ratio is corrected. Removing all tillers except the main one, in a japonica (Sakha 101) and an indica (IR64) rice cultivar, instantly increased the root/shoot ratio from 0.21 to 1.16 in Sakha 101 and from 0.16 to 1.46 in IR64. Over 30 days after detillering, the root/shoot ratios of the detillered plants decreased to 0.49 in Sakha 101 and 0.46 in IR64 but remained significantly higher than in the controls. The detillered plants showed two- or fourfold increase in the main tiller fresh weight, as a consequence of more positive midday leaf relative water content (RWC), and consistently higher rates of stomatal conductance and photosynthesis, but not transpiration, compared with the controls. The enhanced photosynthesis in Sakha 101 after detillering resulted from both improved water status and higher Rubisco contents whereas in IR64, increasing the Rubisco content did not contribute to improving photosynthesis. Detillering did not increase the carbohydrate contents of leaves but prevented starch depletion at the end of grain filling. The leaf protein content during vegetative and reproductive stages, the grain filling rate, the number of filled grains per panicle were greatly improved, bringing about 38.3 and 35.9% increase in the harvested grain dry weight per panicle in Sakha 101 and IR64, respectively. We provide evidence that improving the root performance by increasing the root/shoot ratio would eliminate the current limitations to photosynthesis and growth in rice. © 2015 Scandinavian Plant Physiology Society.

Sealing ability of three root-end filling materials prepared using an erbium: Yttrium aluminium garnet laser and endosonic tip evaluated by confocal laser scanning microscopy

PubMed Central

Nanjappa, A Salin; Ponnappa, KC; Nanjamma, KK; Ponappa, MC; Girish, Sabari; Nitin, Anita

2015-01-01

Aims: (1) To compare the sealing ability of mineral trioxide aggregate (MTA), Biodentine, and Chitra-calcium phosphate cement (CPC) when used as root-end filling, evaluated under confocal laser scanning microscope using Rhodamine B dye. (2) To evaluate effect of ultrasonic retroprep tip and an erbium:yttrium aluminium garnet (Er:YAG) laser on the integrity of three different root-end filling materials. Materials and Methods: The root canals of 80 extracted teeth were instrumented and obturated with gutta-percha. The apical 3 mm of each tooth was resected and 3 mm root-end preparation was made using ultrasonic tip (n = 30) and Er:YAG laser (n = 30). MTA, Biodentine, and Chitra-CPC were used to restore 10 teeth each. The samples were coated with varnish and after drying, they were immersed in Rhodamine B dye for 24 h. The teeth were then rinsed, sectioned longitudinally, and observed under confocal laser scanning microscope. Statistical Analysis Used: Data were analyzed using one-way analysis of variance (ANOVA) and a post-hoc Tukey's test at P < 0.05 (R software version 3.1.0). Results: Comparison of microleakage showed maximum peak value of 0.45 mm for Biodentine, 0.85 mm for MTA, and 1.05 mm for Chitra-CPC. The amount of dye penetration was found to be lesser in root ends prepared using Er:YAG laser when compared with ultrasonics, the difference was found to be statistically significant (P < 0.05). Conclusions: Root-end cavities prepared with Er:YAG laser and restored with Biodentine showed superior sealing ability compared to those prepared with ultrasonics. PMID:26180420

Effectiveness of several solutions to prevent the formation of precipitate due to the interaction between sodium hypochlorite and chlorhexidine and its effect on bond strength of an epoxy-based sealer.

PubMed

Magro, M G; Kuga, M C; Aranda-Garcia, A J; Victorino, K R; Chávez-Andrade, G M; Faria, G; Keine, K C; Só, M V R

2015-05-01

To evaluate the effectiveness of isopropyl alcohol, saline or distilled water to prevent the precipitate formed between sodium hypochlorite (NaOCl) and chlorhexidine (CHX) and its effect on the bond strength of an epoxy-based sealer in radicular dentine. The root canals of 50 extracted human canines (n = 10) were instrumented. In G1, root canals were irrigated with 17% EDTA and 2.5% NaOCl; G2, as G1, except that 2% CHX was used as the final irrigant. In the other groups, intermediate flushes with isopropyl alcohol (G3), saline (G4) or distilled water (G5) were used between NaOCl and CHX. The specimens were submitted to SEM analysis to evaluate the presence of debris and smear layer, in the apical and cervical segments. In sequence, fifty extracted human canines were distributed into five groups (n = 10), similar to the SEM study. After root filling, the roots were sectioned transversally to obtain dentine slices, in the cervical, middle and apical thirds. The root filling was submitted to a push-out bond strength test using an electromechanical testing machine. Statistical analysis was performed using Kruskal-Wallis and Dunn's tests (α = 5%). All groups had similar amounts of residue precipitated on the canal walls (P > 0.05). The push-out bond strength values were similar for all groups, independently of the root third evaluated (P > 0.05). Isopropyl alcohol, saline and distilled water failed to prevent the precipitation of residues on canal walls following the use of NaOCl and CHX. The residues did not interfere with the push-out bond strength of the root filling. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

[Thermoplasticized gutta percha in apexification].

PubMed

Vicente Gómez, A; Miñana Laliga, R

1990-01-01

Filling the root canals in teeth after apexification is one useful clinical application of the thermoplasticized gutta-percha. We described 7 cases which Ultrafil was used in order to fill the canals. In all of them we made X-ray check-up.

MTA and F-doped MTA cements used as sealers with warm gutta-percha. Long-term study of sealing ability.

PubMed

Gandolfi, M G; Prati, C

2010-10-01

To evaluate the long-term sealing ability (up to 6 months) of two experimental calcium silicate MTA cements used as root canal sealers in association with warm gutta-percha. Calcium silicate (MTA) and calcium-fluoro-silicate powders were prepared. Sodium fluoride was included in FMTA (Fluoride-doped Mineral Trioxide Aggregate) as an expansive and retardant agent. Single-rooted teeth were instrumented with NiTi rotary instruments, filled with warm gutta-percha in association with one of the experimental sealers or with AH Plus as a control (n = 20 for each sealer) and stored at 37 °C. Sealing was assessed at 24, 48 h, 1, 2 weeks and 1, 3, 6 months by a fluid filtration method. Scanning electron microscopy with energy dispersive analysis (SEM/EDX) was used to study the dentine/sealer interface of roots stored for 6 months and the surface of cement disks stored for 24 h. All sealers revealed a statistically significant reduction (P < 0.05) in fluid filtration after the first 2 weeks. No statistically significant differences were observed between FMTA and AH Plus at all analysis times. At short times (24, 48-h), no statistically significant differences were found between the experimental cements and AH Plus. At long-term evaluations (1, 3, 6 months), FMTA and AH Plus sealed significantly better (P < 0.05) than MTA. FMTA was associated with lower fluid filtration rates, and the seal was stable from 48 h to 6 months, thus proving the most effective material. Scanning electron microscopy with energy dispersive analysis of root sections filled with calcium silicate sealers revealed the formation of a blend layer of gutta-percha and cement consequent to the warm gutta-percha condensation technique. Scanning electron microscopy with energy dispersive analysis of 24-h-stored disks identified a Ca-rich coating on the outer surface consisting of globular particles (calcium hydroxide and calcium carbonate), and a deeper internal Ca- and Si-rich region consisting of needle-like ettringite crystals and round formations of calcium silicate hydrate gel. Fluoride-doped MTA demonstrated stable sealing during a period of up to 6 months and significantly better than conventional calcium silicate MTA cements and comparable to AH Plus. The study supports the suitability of calcium silicate MTA cements as sealers in association with warm gutta-percha for root filling. © 2010 International Endodontic Journal.

New bacterial composition in primary and persistent/secondary endodontic infections with respect to clinical and radiographic findings.

PubMed

Tennert, Christian; Fuhrmann, Maximilian; Wittmer, Annette; Karygianni, Lamprini; Altenburger, Markus J; Pelz, Klaus; Hellwig, Elmar; Al-Ahmad, Ali

2014-05-01

The aim of the present study was to analyze the microbiota of primary and secondary/persistent endodontic infections of patients undergoing endodontic treatment with respect to clinical and radiographic findings. Samples from the root canals of 21 German patients were taken using 3 sequential sterile paper points. In the case of a root canal filling, gutta-percha was removed with sterile files, and samples were taken using sterile paper points. The samples were plated, and microorganisms were then isolated and identified morphologically by biochemical analysis and sequencing the 16S rRNA genes of isolated microorganisms. In 12 of 21 root canals, 33 different species could be isolated. Six (50%) of the cases with isolated microorganisms were primary, and 6 (50%) cases were endodontic infections associated with root-filled teeth. Twelve of the isolated species were facultative anaerobic and 21 obligate anaerobic. Monomicrobial infections were found for Enterococcus faecalis and Actinomyces viscosus. E. faecalis was most frequently isolated in secondary endodontic infections (33%). Moraxella osloensis was isolated from a secondary endodontic infection that had an insufficient root canal filling accompanied by a mild sensation of pain. A new bacterial composition compromising Atopobium rimae, Anaerococcus prevotii, Pseudoramibacter alactolyticus, Dialister invisus, and Fusobacterium nucleatum was recovered from teeth with chronic apical abscesses. New bacterial combinations were found and correlated to clinical and radiographic findings, particularly to chronic apical abscesses. M. osloensis was detected in root canals for the second time and only in German patients. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Healing Process Following Application of Set or Fresh Mineral Trioxide Aggregate as a Root-End Filling Material

PubMed Central

Habibi, Mehdi; Ghoddusi, Jamileh; Habibi, Ataollah; Mohtasham, Nooshin

2011-01-01

Objectives: An unsuccessful attempt to reach the apical area or to place the retrograde material is a major difficulty in periradicular surgery. The aim of this study was to compare the histological evaluation of the healing process following an orthograde versus a retrograde application of mineral trioxide aggregate (MTA) as a root-end filling material during apical surgery on cats’ teeth in order to find out whether orthograde placement of MTA before surgery can be used instead of retrograde placement during surgery. Methods: In this experimental study, 24 canine teeth in 12 mature and healthy cats were filled with either MTA or gutta-percha in an orthograde manner. Two weeks later, the teeth with MTA were surgically exposed and resected to the set-MTA within the canals. The teeth previously filled by gutta-percha were also surgically exposed, and retrograde cavities were prepared at the root ends and filled with fresh-MTA. After 8 weeks, the animals were euthanized by vital perfusion. Six-micron histological slices were prepared from samples, stained by Hematoxylin & Eosin, and histologically studied by means of a light microscope. The collected data was analyzed by the Chi-square and the T-test. Results: One of the samples in the fresh-MTA group was omitted during processing because of inappropriate sectioning. In the set-MTA group, 5 out of 12 showed chronic abscess, while in the fresh-MTA group, 2 out of 11 were discovered to have chronic abscess; however, no significant difference was observed (P>.05). Hard tissue healing (cementum, bone, cementum + bone formation) in the set-MTA and fresh-MTA groups were 7 out of 12 and 9 out of 11, respectively. While healing seemed more likely to occur in the fresh-MTA group, the difference was statistically insignificant (P>.05). The magnitude of bone, cementum, or bone and cementum formation showed slight differences between the two groups; however, the figures failed to show any marked differences (P>.05). Conclusions: Orthograde placement of MTA could be used as an obturation material before surgery. In this way, after root-end resection, there would be no need for root-end preparation and filling procedures. PMID:21228953

Effectiveness of ProTaper, D-RaCe, and Mtwo retreatment files with and without supplementary instruments in the removal of root canal filling material.

PubMed

Marques da Silva, B; Baratto-Filho, F; Leonardi, D P; Henrique Borges, A; Volpato, L; Branco Barletta, F

2012-10-01

To assess the efficacy of different retreatment rotary files in removing gutta-percha and endodontic sealer from canals. Ninety straight single-rooted premolars were prepared up to a size 30 and filled with gutta-percha and sealer and then randomly assigned to six retreatment groups (n = 15). Groups I, III, and V were retreated using rotary systems ProTaper Universal Retreatment (PTUR), D-RaCe, and Mtwo Retreatment, respectively. Groups II, IV, and VI were retreated using the additional instruments F4, size 40, .04 taper RaCe, and size 40, .04 taper Mtwo, respectively. The roots were split vertically, and images of the halves were obtained using a high-resolution scanner and evaluated with AutoCAD software to calculate the percentage of residual material. Data were analyzed with Kruskal-Wallis and Student-Newman-Keuls tests using a 5% significance cutoff (P < 0.05). There were no statistically significant differences (P > 0.05) between groups when additional instruments were used. The percentage of residual material was lowest in the PTUR group and was statistically significant only when compared to the D-RaCe system (P = 0.0038). All root canals had residual filling material after retreatment even when additional instruments were used. © 2012 International Endodontic Journal.

Bacterial leakage in root canals filled with AH Plus and dentine bonding agents.

PubMed

Navarro-Escobar, Esther; Baca, Pilar; Ruiz-Linares, Matilde; Arias-Moliz, Maria Teresa; Perez-Heredia, Mercedes; Ferrer-Luque, Carmen Maria

2014-11-01

The aim of this study was to compare the efficacy of different dentine adhesives in delaying the coronal bacterial leakage of Enterococcus faecalis in filled root canals. Materials and methods. Ninety-five lower incisors of patients >65 years of age were instrumented using the ProTaper system and were irrigated with 1 mL of 2.5% sodium hypochlorite (NaOCl) alternated with 1 mL 17% EDTA between each file change. Final irrigation was performed with 5 mL of 17% EDTA and then flushed with 5 mL of distilled water. The teeth were randomly divided into five experimental groups (n = 15/group) and one of the following dentine adhesives was applied: (1) AdheSE; (2) Excite DSC; (3) Clearfil Protect Bond; (4) One Coat 7.0; or (5) Control group without adhesive. After filling the root canals, the samples were mounted on a double chamber device to evaluate the bacterial filtration of E. faecalis during a period of 240 days. The results underwent non-parametric Kaplan-Meier survival analysis and comparisons among groups were done using the Log-Rank test. At 240 days, E. faecalis was detected in samples of all groups in the lower chamber. The highest survival value was obtained by One Coat 7.0, giving statistically significant differences from the other groups, whereas Clearfil Protect Bond, AdheSE and Excite DSC showed similar behaviours, likewise similar to the Control group. One Coat 7.0 adhesive system provides the longest survival value to delay E. faecalis coronal leakage in filled root canals.

Effects of combining CBCT technology with visual root canal recurrence in treatment of elderly patients with dental pulp disease.

PubMed

Cui, J-J; Peng, B; Lin, W

2017-03-01

The aim of this study is to analyze the effects of combining cone beam computed tomography (CBCT) technology with visual root canal recurrence in the treatment of elderly patients with dental pulp disease. 56 cases of elderly patients with dental pulp disease were contiguously selected, and randomly divided into the control group (70 teeth from 27 patients) and the observation group (77 teeth from the rest 29 patients). We adopted CBCT technology combined with conventional root canal therapy in control group and CBCT technology combined with visual root canal recurrence in observation group to compare the clinical effects. It was found that there was no statistical difference in duration of operation between the two groups (p>0.05). The operation times and the VAS during and after operation of the observation group were significantly less than that of the control group (p<0.05). The duration of follow-up of the two groups was both about 18 months. Successful rates of treatment for 6 months and by the end of follow-up visit in the observation group were both significantly higher than those in the control group (p<0.05). The correct filling rate, good filling rate and fair filling rate in the observation group were significantly higher than those of the control group (p<0.05). CBCT technology combined with visual root canal recurrence can significantly improve the near and long-term treatment effects of elderly patients with dental pulp disease.

Plasticity of rhizosphere hydraulic properties as a key for efficient utilization of scarce resources

PubMed Central

Carminati, Andrea; Vetterlein, Doris

2013-01-01

Background It is known that the soil near roots, the so-called rhizosphere, has physical and chemical properties different from those of the bulk soil. Rhizosphere properties are the result of several processes: root and soil shrinking/swelling during drying/wetting cycles, soil compaction by root growth, mucilage exuded by root caps, interaction of mucilage with soil particles, mucilage shrinking/swelling and mucilage biodegradation. These processes may lead to variable rhizosphere properties, i.e. the presence of air-filled gaps between soil and roots; water repellence in the rhizosphere caused by drying of mucilage around the soil particles; or water accumulation in the rhizosphere due to the high water-holding capacity of mucilage. The resulting properties are not constant in time but they change as a function of soil condition, root growth rate and mucilage age. Scope We consider such a variability as an expression of rhizosphere plasticity, which may be a strategy for plants to control which part of the root system will have a facilitated access to water and which roots will be disconnected from the soil, for instance by air-filled gaps or by rhizosphere hydrophobicity. To describe such a dualism, we suggest classifying rhizosphere into two categories: class A refers to a rhizosphere covered with hydrated mucilage that optimally connects roots to soil and facilitates water uptake from dry soils. Class B refers to the case of air-filled gaps and/or hydrophobic rhizosphere, which isolate roots from the soil and may limit water uptake from the soil as well water loss to the soil. The main function of roots covered by class B will be long-distance transport of water. Outlook This concept has implications for soil and plant water relations at the plant scale. Root water uptake in dry conditions is expected to shift to regions covered with rhizosphere class A. On the other hand, hydraulic lift may be limited in regions covered with rhizosphere class B. New experimental methods need to be developed and applied to different plant species and soil types, in order to understand whether such dualism in rhizosphere properties is an important mechanism for efficient utilization of scarce resources and drought tolerance. PMID:23235697

Phytoremediation of soils contaminated by cadmium

NASA Astrophysics Data System (ADS)

Watai, H.; Miyazaki, T.; Fujikawa, T.; Mizoguchi, M.

2004-12-01

Phytoremediation is a technique to clean up soils contaminated with heavy metals. Advantages of this method are that (1) This technique is suitable to cleanup soils slightly contaminated with heavy metals in relatively wide area. (2) The expense for clean up is lower than civil engineering techniques. (3) This method can remove heavy metals fundamentally from contaminated. (4) The heavy metals are able to recycle by ashing of plants. Many researches have been done on the phytoremediation up to now, but almost all these researches were devoted to clarify the phytoremediation from the view point of plants themselves. However, few efforts have been devoted to analyze the migrations of heavy metals in soils during the phytoremediation process. The objective of this study is to clarify the features of Cd migration when plant roots are absorbing Cd from the ambient soils. Especially, we focused on finding the Cd migration pattern by changing the soil condition such as plant growing periods, planting densities, and the initial Cd concentration in soils. We planted sunflowers in columns filled with Cd contaminated soils because sunflower is a well-known hyperaccumulator of Cd from soils. By cutting the shoots of plants at the soil surface, and by keeping the plant roots in the soils without disturbance, the Cd concentrations, moisture contents, pH distributions, EC distributions, and dry weight of residual roots in the soils were carefully analyzed. The experimental results showed that (1)The growth of the planted sunflowers were suffered by applying of Cd. (2)The decrease of suction was affected by water uptake by roots at the depth from 0 to 5 cm. Water contents with plants in soils decrease more than without plants. (3)Cd adsorption by roots was predominant within 5cm from soil surface. In addition, it was also shown that there was an optimal Cd concentration where Cd is most effectively adsorbed by the plant. In this experiment we found that 40 to 60 mg kg-1 was the optimal concentration. By a trial calculation, it was revealed that more than 30 times of planting-cultivating processes were needed to decrease the Cd concentration from 9.75 to 0.4 mg Cd kg-1. When the sunflower was not planted, Cd did not move in the soils even when the soil water the sunflower was planted, Cd in the soil moved toward the plant roots associating with the water uptake by the roots. This Cd movement may have enhanced by the secretion of organic acid from plant roots.

Apical third enlargement of the root canal and its relationship with the repair of periapical lesions

PubMed Central

Souza, Ronaldo Araújo; Dantas, João Costa Pinto; Brandão, Paula Maciel; Colombo, Suely; Lago, Maurício; Duarte, Marco Antônio Húngaro

2012-01-01

Objective: The purpose of this study was to evaluate if the apical third enlargement of root canal is the determinant factor for the repair of periapical lesions in endodontic treatment. Methods: Eighty upper and lower incisors, canines and premolars with periapical lesions were randomly divided in 2 groups and were treated by undergraduate students. Canals were instrumented with up to 3 files in group I (n = 40) and up to 4 files in group II (n = 40) 1 mm short of the apex and were filled with a calcium hydroxide dressing. After removing calcium hydroxide 14 days later, both groups were filled using the lateral condensation technique. In the 2-year follow-up, a few patients did not return, and some cases did not present conditions for accurate comparisons. Therefore, only 43 patients (24 in group I and 19 in group II) presented conditions for radiographic comparisons. Data were statistically analyzed using Fisher's exact test. Results: Comparison of the initial and follow-up radiographs showed that 22 out of 24 (91.67%) patients in group I and 17 out of 19 patients (89.47%) in group II showed repair. Statistical analysis revealed no significant differences between the groups (P>.05). Conclusion: The results of this study show that the apical third enlargement did not alter the outcome of endodontic treatment of teeth with periapical lesion performed by undergraduate students. PMID:23077417

Persistent extraradicular infection in root-filled asymptomatic human tooth: scanning electron microscopic analysis and microbial investigation after apical microsurgery.

PubMed

Signoretti, Fernanda G C; Endo, Marcos S; Gomes, Brenda P F A; Montagner, Francisco; Tosello, Fernanda B; Jacinto, Rogério C

2011-12-01

Procedural accidents have a negative effect on healing and might contribute to the persistence of infections in inaccessible apical areas, requiring surgical intervention. This report describes a case of persistent apical periodontitis of a lower left first molar associated with the sinus tract and a periapical lesion that required nonsurgical endodontic retreatment and apical surgery for resolution. The tooth had received endodontic treatment 3 years ago and had to be retreated using the crown-down technique with chemical auxiliary substance (2% chlorhexidine gel), foramen patency, and enlargement and was filled in a single appointment. The occlusal access cavity was immediately restored with composite resin. After 1 month, it could be observed that the sinus tract persisted and, radiographically, the lesion remained unaltered. Therefore, endodontic microsurgery was indicated. Apical microsurgery was performed under magnification with the use of a dental operating microscope including apicectomy, root end with ultrasound, and sealing with mineral trioxide aggregate. A microbiological sample was collected from the apical lesion. The resected distal root apex was observed by scanning electron microscopy. The following species were detected: Actinomyces naeslundii and Actinomyces meyeri, Propionibacterium propionicum, Clostridium botullinum, Parvimonas micra, and Bacteroides ureolyticus; scanning electron microscopic analysis revealed bacterial biofilm surrounding the apical foramen and external radicular surface. Gutta-percha overfilling at the apex because of a zip caused during initial endodontic treatment could be observed. A 6-month follow-up showed apparent radiographic periapical healing, which progressed after 24 months. Gram-positive anaerobic bacteria and extraradicular biofilm seem to participate in the maintenance of persistent periapical pathology, and endodontic retreatment followed by periapical microsurgery proved to be a successful alternative in the resolution of persistent extraradicular infections. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The efficacy of the self-adjusting file and ProTaper for removal of calcium hydroxide from root canals

PubMed Central

FARIA, Gisele; KUGA, Milton Carlos; RUY, Alessandra Camila; ARANDA-GARCIA, Arturo Javier; BONETTI-FILHO, Idomeo; GUERREIRO-TANOMARU, Juliane Maria; LEONARDO, Renato Toledo

2013-01-01

Objective The goal of this study was to evaluate the efficacy of the Self-Adjusting File (SAF) and ProTaper for removing calcium hydroxide [Ca(OH)2] from root canals. Material and Methods Thirty-six human mandibular incisors were instrumented with the ProTaper system up to instrument F2 and filled with a Ca(OH)2-based dressing. After 7 days, specimens were distributed in two groups (n=15) according to the method of Ca(OH)2 removal. Group I (SAF) was irrigated with 5 mL of NaOCl and SAF was used for 30 seconds under constant irrigation with 5 mL of NaOCl using the Vatea irrigation device, followed by irrigation with 3 mL of EDTA and 5 mL of NaOCl. Group II (ProTaper) was irrigated with 5 mL of NaOCl, the F2 instrument was used for 30 seconds, followed by irrigation with 5 mL of NaOCl, 3 mL of EDTA, and 5 mL of NaOCl. In 3 teeth Ca(OH)2 was not removed (positive control) and in 3 teeth canals were not filled with Ca(OH)2 (negative control). Teeth were sectioned and prepared for the scanning electron microscopy. The amounts of residual Ca(OH)2 were evaluated in the middle and apical thirds using a 5-score system. Results None of the techniques completely removed the Ca(OH)2 dressing. No difference was observed between SAF and ProTaper in removing Ca(OH)2 in the middle (P=0.11) and the apical (P=0.23) thirds. Conclusion The SAF system showed similar efficacy to rotary instrument for removal of Ca(OH)2 from mandibular incisor root canals. PMID:24037074

In Vitro Comparison of Gutta-Percha Removal with H-File and ProTaper with or without Chloroform

PubMed Central

Khalilak, Zohreh; Vatanpour, Mehdi; Dadresanfar, Bahareh; Moshkelgosha, Pouneh; Nourbakhsh, HamidReza

2013-01-01

Introduction Removal of root filling materials is one of the key steps in success of root canal retreatment. The purpose of this study was to evaluate the efficacy of H-File and ProTaper with or without chloroform in the removal of gutta-percha during retreatment of mandibular premolars. Materials and Methods Sixty mandibular premolars with one canal, and curvatures less than 30 degrees were used in this experimental study. They were instrumented with K-files and laterally obturated with condensed gutta-percha using AH26 as the sealer and were stored in 100% humidity at 37°C for 2 weeks. The teeth were randomly divided into four groups of 15 teeth each. Removal of gutta-percha was performed with H-File and ProTaper. All techniques were used with or without chloroform. The teeth were split longitudinally and the area of remaining gutta-percha/sealer on the root canal wall was explored under stereomicroscope. Retreatment time duration was also recorded for each sample. Data were analyzed statistically by Two-way ANOVA, t-test and Tukey’s. Results In all groups, no significant difference was found in remaining gutta-percha and sealer with or without using chloroform, but chloroform shortened the time of retreatment. ProTaper left significantly less remaining filling materials than H-File (P<0.05). Retreatment time was significantly different between the studied groups (P<0.001). Conclusion ProTaper Ni-Ti instruments proved to be more efficient and time-saving devices for removal of gutta-percha compared to H-File in canals with no or slight curvature. PMID:23413203

Micro-computed tomography analysis of post space preparation in root canals filled with carrier-based thermoplasticized gutta-percha.

PubMed

Schroeder, A A; Ford, N L; Coil, J M

2017-03-01

To determine whether post space preparation deviated from the root canal preparation in canals filled with Thermafil, GuttaCore or warm vertically compacted gutta-percha. Forty-two extracted human permanent maxillary lateral incisors were decoronated, and their root canals instrumented using a standardized protocol. Samples were divided into three groups and filled with Thermafil (Dentsply Tulsa Dental Specialties, Johnson City, TN, USA), GuttaCore (Dentsply Tulsa Dental Specialties) or warm vertically compacted gutta-percha, before post space preparation was performed with a GT Post drill (Dentsply Tulsa Dental Specialties). Teeth were scanned using micro-computed tomography after root filling and again after post space preparation. Scans were examined for number of samples with post space deviation, linear deviation of post space preparation and minimum root thickness before and after post space preparation. Parametric data were analysed with one-way analysis of variance (anova) or one-tailed paired Student's t-tests, whilst nonparametric data were analysed with Fisher's exact test. Deviation occurred in eight of forty-two teeth (19%), seven of fourteen from the Thermafil group (50%), one of fourteen from the GuttaCore group (7%), and none from the gutta-percha group. Deviation occurred significantly more often in the Thermafil group than in each of the other two groups (P < 0.05). Linear deviation of post space preparation was greater in the Thermafil group than in both of the other groups and was significantly greater than that of the gutta-percha group (P < 0.05). Minimum root thickness before post space preparation was significantly greater than it was after post space preparation for all groups (P < 0.01). The differences between the Thermafil, GuttaCore and gutta-percha groups in the number of samples with post space deviation and in linear deviation of post space preparation were associated with the presence or absence of a carrier as well as the different carrier materials. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

A microleakage study of gutta-percha/AH Plus and Resilon/Real self-etch systems after different irrigation protocols

PubMed Central

PRADO, Maíra; SIMÃO, Renata Antoun; GOMES, Brenda Paula Figueiredo de Almeida

2014-01-01

The development and maintenance of the sealing of the root canal system is the key to the success of root canal treatment. The resin-based adhesive material has the potential to reduce the microleakage of the root canal because of its adhesive properties and penetration into dentinal walls. Moreover, the irrigation protocols may have an influence on the adhesiveness of resin-based sealers to root dentin. Objective The objective of the present study was to evaluate the effect of different irrigant protocols on coronal bacterial microleakage of gutta-percha/AH Plus and Resilon/Real Seal Self-etch systems. Material and Methods One hundred ninety pre-molars were used. The teeth were divided into 18 experimental groups according to the irrigation protocols and filling materials used. The protocols used were: distilled water; sodium hypochlorite (NaOCl)+eDTA; NaOCl+H3PO4; NaOCl+eDTA+chlorhexidine (CHX); NaOCl+H3PO4+CHX; CHX+eDTA; CHX+ H3PO4; CHX+eDTA+CHX and CHX+H3PO4+CHX. Gutta-percha/AH Plus or Resilon/Real Seal Se were used as root-filling materials. The coronal microleakage was evaluated for 90 days against Enterococcus faecalis. Data were statistically analyzed using Kaplan-Meier survival test, Kruskal-Wallis and Mann-Whitney tests. Results No significant difference was verified in the groups using chlorhexidine or sodium hypochlorite during the chemo-mechanical preparation followed by eDTA or phosphoric acid for smear layer removal. The same results were found for filling materials. However, the statistical analyses revealed that a final flush with 2% chlorhexidine reduced significantly the coronal microleakage. Conclusion A final flush with 2% chlorhexidine after smear layer removal reduces coronal microleakage of teeth filled with gutta-percha/AH Plus or Resilon/Real Seal SE. PMID:25025557

The efficiency of different irrigation solutions and techniques for the removal of triple antibiotic paste from simulated immature root canals.

PubMed

Ustun, Y; Düzgün, S; Aslan, T; Aktı, A

2018-03-01

The purpose of this study was to evaluate the efficiencies of different irrigation protocols in the removal of triple antibiotic paste (TAP) from root canals. A total of 127 extracted human maxillary incisor teeth were prepared. Then, root-end resection of 3 mm was accomplished to simulate immature apex model. The root canals were filled with TAP, after 21 days, randomly divided into nine groups according to irrigation systems and solutions (n = 13). Conventional irrigation (CI) groups - Group 1: Root canal irrigation was performed with CI by Peracetic acid (PAA) solution, Group 2: Root canal irrigation was performed with CI by etidronic acid 1-hydroxyethylidene-1, 1-bisphosphonate (HEBP) + sodium hypochlorite (NaOCl) solution, Group 3: Root canal irrigation was performed with CI by ethylenediaminetetraacetic acid (EDTA)/NaOCl solutions. Vibringe system groups - Group 4: Root canal irrigation was performed with Vibringe system by PAA solution, Group 5: Root canal irrigation was performed with Vibringe system by HEBP + NaOCl solution, Group 6: Root canal irrigation was performed with Vibringe system by EDTA/NaOCl solution. EndoVac system groups - Group 7: Root canal irrigation was performed with EndoVac system by PAA solution, Group 8: Root canal irrigation was performed with EndoVac system by HEBP + NaOCl solution, Group 9: Root canal irrigation was performed with EndoVac system by EDTA/NaOCl solution. Control Group: (n = 0). Samples were sectioned vertically, and the amount of remaining medicament was scored for each root half and data were statistically analyzed. Among the irrigation systems, CI groups showed the highest scores at both apical and coronal parts (P < 0.05). In comparisons among the solutions, at the apical part, PAA groups showed the highest scores (P < 0.05). At the coronal part, EDTA + NaOCl groups showed the lowest score values (P < 0.05). The use of irrigation systems improved the removal of TAP from the simulated immature root canals. Also, as an irrigation solution EDTA gives more promising results than PAA and HEBP solutions.

Efficacy of Different Methods for Removing Root Canal Filling Material in Retreatment - An In-vitro Study.

PubMed

Kasam, Swetha; Mariswamy, Annapoorna Ballagere

2016-06-01

Although success of endodontic therapy has significantly improved in the last few decades due to the introduction of novel materials and techniques, failures of endodontic therapy requiring re-treatment still comprise a significant percentage of patients requiring root canal treatment. To evaluate and compare the effective removal of gutta percha and sealer, amount of apical debris extrusion and time required for gutta percha removal using various endodontic files. Total 48 extracted mandibular premolars were mounted on acrylic blocks and endodontic procedure was carried out using size 40 K file and obturated using guttapercha and zinc oxide eugenol sealer. After one month storage, samples were decoronated, mounted on screw capped vials and subjected to removal of obturated material by four instruments: H files, safe sided H files, protaper universal retreatment rotary system and ultrasonic retreatment tip, grouped as 1, 2, 3, and 4 respectively. Only 2mm of obturated material from the coronal part was removed using no. 3 Gates Glidden drill, guttapercha was softened with a drop of xylene for 2 mins for each canal and retreatment was performed. The retreatment procedure was said to be complete when no visible debris were observed on the instrument flutes. The samples split into two halves and examined under stereomicroscope, photographed, assessed using AUTOCAD software and percentage of remaining filling material in coronal, middle, apical thirds of the canal was calculated in mm(2). Retreatment time was recorded in seconds and apically extruded debris was assessed by microbalance in grams for each tooth. The data was analyzed by using descriptive statistics, ANOVA and Scheffe's post hoc test through SPSS for windows (v 16.0). The ultrasonic retreatment tip had less percentage of residual guttapercha/sealer, shorter mean operating time and little apical extrusion with a significant difference (p<0.05) between the other groups. All techniques retained guttapercha/sealer remnants within the root canal. The ultrasonic retreatment tip proved to be an efficient method of removing obturated material. It was fastest with least apical debris extrusion.

Efficacy of Different Methods for Removing Root Canal Filling Material in Retreatment - An In-vitro Study

PubMed Central

Mariswamy, Annapoorna Ballagere

2016-01-01

Introduction Although success of endodontic therapy has significantly improved in the last few decades due to the introduction of novel materials and techniques, failures of endodontic therapy requiring re-treatment still comprise a significant percentage of patients requiring root canal treatment. Aim To evaluate and compare the effective removal of gutta percha and sealer, amount of apical debris extrusion and time required for gutta percha removal using various endodontic files. Materials and Methods Total 48 extracted mandibular premolars were mounted on acrylic blocks and endodontic procedure was carried out using size 40 K file and obturated using guttapercha and zinc oxide eugenol sealer. After one month storage, samples were decoronated, mounted on screw capped vials and subjected to removal of obturated material by four instruments: H files, safe sided H files, protaper universal retreatment rotary system and ultrasonic retreatment tip, grouped as 1, 2, 3, and 4 respectively. Only 2mm of obturated material from the coronal part was removed using no. 3 Gates Glidden drill, guttapercha was softened with a drop of xylene for 2 mins for each canal and retreatment was performed. The retreatment procedure was said to be complete when no visible debris were observed on the instrument flutes. The samples split into two halves and examined under stereomicroscope, photographed, assessed using AUTOCAD software and percentage of remaining filling material in coronal, middle, apical thirds of the canal was calculated in mm2. Retreatment time was recorded in seconds and apically extruded debris was assessed by microbalance in grams for each tooth. The data was analyzed by using descriptive statistics, ANOVA and Scheffe’s post hoc test through SPSS for windows (v 16.0). Results The ultrasonic retreatment tip had less percentage of residual guttapercha/sealer, shorter mean operating time and little apical extrusion with a significant difference (p<0.05) between the other groups. Conclusion All techniques retained guttapercha/sealer remnants within the root canal. The ultrasonic retreatment tip proved to be an efficient method of removing obturated material. It was fastest with least apical debris extrusion. PMID:27504397

Comparing simple root phenotyping methods on a core set of rice genotypes.

PubMed

Shrestha, R; Al-Shugeairy, Z; Al-Ogaidi, F; Munasinghe, M; Radermacher, M; Vandenhirtz, J; Price, A H

2014-05-01

Interest in belowground plant growth is increasing, especially in relation to arguments that shallow-rooted cultivars are efficient at exploiting soil phosphorus while deep-rooted ones will access water at depth. However, methods for assessing roots in large numbers of plants are diverse and direct comparisons of methods are rare. Three methods for measuring root growth traits were evaluated for utility in discriminating rice cultivars: soil-filled rhizotrons, hydroponics and soil-filled pots whose bottom was sealed with a non-woven fabric (a potential method for assessing root penetration ability). A set of 38 rice genotypes including the OryzaSNP set of 20 cultivars, additional parents of mapping populations and products of marker-assisted selection for root QTLs were assessed. A novel method of image analysis for assessing rooting angles from rhizotron photographs was employed. The non-woven fabric was the easiest yet least discriminatory method, while the rhizotron was highly discriminatory and allowed the most traits to be measured but required more than three times the labour of the other methods. The hydroponics was both easy and discriminatory, allowed temporal measurements, but is most likely to suffer from artefacts. Image analysis of rhizotrons compared favourably to manual methods for discriminating between cultivars. Previous observations that cultivars from the indica subpopulation have shallower rooting angles than aus or japonica cultivars were confirmed in the rhizotrons, and indica and temperate japonicas had lower maximum root lengths in rhizotrons and hydroponics. It is concluded that rhizotrons are the preferred method for root screening, particularly since root angles can be assessed. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

Processing and statistical analysis of soil-root images

NASA Astrophysics Data System (ADS)

Razavi, Bahar S.; Hoang, Duyen; Kuzyakov, Yakov

2016-04-01

Importance of the hotspots such as rhizosphere, the small soil volume that surrounds and is influenced by plant roots, calls for spatially explicit methods to visualize distribution of microbial activities in this active site (Kuzyakov and Blagodatskaya, 2015). Zymography technique has previously been adapted to visualize the spatial dynamics of enzyme activities in rhizosphere (Spohn and Kuzyakov, 2014). Following further developing of soil zymography -to obtain a higher resolution of enzyme activities - we aimed to 1) quantify the images, 2) determine whether the pattern (e.g. distribution of hotspots in space) is clumped (aggregated) or regular (dispersed). To this end, we incubated soil-filled rhizoboxes with maize Zea mays L. and without maize (control box) for two weeks. In situ soil zymography was applied to visualize enzymatic activity of β-glucosidase and phosphatase at soil-root interface. Spatial resolution of fluorescent images was improved by direct application of a substrate saturated membrane to the soil-root system. Furthermore, we applied "spatial point pattern analysis" to determine whether the pattern (e.g. distribution of hotspots in space) is clumped (aggregated) or regular (dispersed). Our results demonstrated that distribution of hotspots at rhizosphere is clumped (aggregated) compare to control box without plant which showed regular (dispersed) pattern. These patterns were similar in all three replicates and for both enzymes. We conclude that improved zymography is promising in situ technique to identify, analyze, visualize and quantify spatial distribution of enzyme activities in the rhizosphere. Moreover, such different patterns should be considered in assessments and modeling of rhizosphere extension and the corresponding effects on soil properties and functions. Key words: rhizosphere, spatial point pattern, enzyme activity, zymography, maize.

High-contrast x-ray microtomography in dental research

NASA Astrophysics Data System (ADS)

Davis, Graham; Mills, David

2017-09-01

X-ray microtomography (XMT) is a well-established technique in dental research. The technique has been used extensively to explore the complex morphology of the root canal system, and to qualitatively and quantitatively evaluate root canal instrumentation and filling efficacy in extracted teeth; enabling different techniques to be compared. Densitometric information can be used to identify and map demineralized tissue resulting from tooth decay (caries) and, in extracted teeth, the method can be used to evaluate different methods of excavation. More recently, high contrast XMT is being used to investigate the relationship between external insults to teeth and the pulpal reaction. When such insults occur, fluid may flow through dentinal tubules as a result of cracking or porosity in enamel. Over time, there is an increase in mineralization along the paths of the tubules from the pulp to the damaged region in enamel and this can be visualized using high contrast XMT. The scanner used for this employs time-delay integration to minimize the effects of detector inhomogeneity in order to greatly increase the upper limit on signal-to-noise ratio that can be achieved with long exposure times. When enamel cracks are present in extracted teeth, the presence of these pathways indicates that the cracking occurred prior to extraction. At high contrast, growth lines are occasionally seen in deciduous teeth which may have resulted from periods of maternal illness. Various other anomalies in mineralization resulting from trauma or genetic abnormalities can also be investigated using this technique.

Complex Apical Intraradicular Infection and Extraradicular Mineralized Biofilms as the Cause of Wet Canals and Treatment Failure: Report of 2 Cases.

PubMed

Ricucci, Domenico; Candeiro, George T M; Bugea, Calogero; Siqueira, José F

2016-03-01

This article describes 2 cases that showed persistent intracanal exudation (wet canal) even after several visits of antimicrobial endodontic treatment. Histologic and histobacteriologic investigation was conducted for determination of the cause. The 2 cases involved teeth with apical periodontitis lesions, which presented persistent exudation refractory to treatment after several visits. In case 1, it was not possible to achieve a dry canal, and surgery had to be performed. In case 2, attempts to dry the canal succeeded and the canal was filled, but follow-up examination showed an enlarged apical periodontitis lesion and extraction was performed. Biopsy specimens consisting of the root apex and apical periodontitis lesion for case 1 and the whole root for case 2 were subjected to histologic and histobacteriologic analyses. Both cases showed complex bacterial infection in the apical root, affecting both the intraradicular space and the outer root surface. Case 1 showed bacterial biofilms in ramifications, on untouched walls, and extending to the external root surface to form a thick and partially mineralized structure with high bacterial density. Different bacterial morphotypes were evidenced. Case 2 had a ledge on the apical canal wall created during instrumentation, which was filled with necrotic debris, filling material, and bacteria. The walls of the apical portion of the canal were covered by a bacterial biofilm, which was continuous with a thick extraradicular biofilm covering the cementum and dentin in resorptive defects. The extraradicular biofilm showed areas of mineralization and was dominated by filamentous bacteria. The 2 cases with wet canals and treatment failure were associated with complex persistent infection in the apical part of the root canal system extending to form thick and partially mineralized biofilm structures (calculus) on the outer apical root surface. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Effect of Different Endodontic Sealers on the Push-out Bond Strength of Fiber Posts.

PubMed

Forough Reyhani, Mohammad; Ghasemi, Negin; Rahimi, Saeed; Milani, Amin Salem; Omrani, Elnaz

2016-01-01

The aim of this in vitro study was to evaluate the effect of MTA-based sealer (MTA Fillapex), eugenol-based sealer (Dorifill) and an epoxy resin sealer (AH Plus) on the bond strength of fiber posts cemented with a self-etch adhesive. The root canals of 72 maxillary incisors were prepared using the step-back technique after removing/cutting off the crowns. The samples were randomly divided to 4 groups (n=18). In group 1 (the controls) gutta-percha was used without sealer. In groups 2, 3 and 4, the canals were filled with gutta-percha using AH Plus, Dorifill and MTA Fillapex sealers, respectively, by cold lateral compaction technique. After post space preparation, the fiber posts were cemented in the root canals using self-etch adhesive. Then 1-mm-thick disks were prepared from the coronal thirds of all the root canals and subjected to a push-out test. Data were analyzed using the one-way ANOVA and post hoc Tukey's tests. The maximum (4.45±0.09 MPa) and minimum (1.02±0.03 MPa) bond strength values were recorded in the control and Dorifill groups, respectively. The mean push-out bond strength values were similar for MTA Fillapex and AH Plus sealers (P>0.05). However these values were significantly higher than that of the Dorifill sealer (P<0.05). Sealer type affected the bond strength of the fiber posts and MTA Fillapex decreased the dislodgment resistant of the fiber post.

Computed tomography (CT) in the selection of treatment for root-filled maxillary molars with apical periodontitis

PubMed Central

Huumonen, Sisko; Molander, Anders; Öhman, Anders; Kvist, Thomas

2016-01-01

Objectives: The aims of this study were to evaluate whether the use of CT facilitates agreement among endodontists in selecting treatments for root-filled maxillary molars with apical periodontitis and to assess the efficacy of CT in choosing a treatment for such teeth. Methods: 39 root-filled maxillary molars from 34 patients with suspected apical periodontitis were independently evaluated by 4 endodontists and 1 postgraduate student (decision-makers). Treatment decisions were made based on intra-oral radiographs and a fictive clinical history. After 1–3 months, the same decision-makers repeated the examination of the same teeth but with additional information from a CT examination. Agreement between decision-makers with or without the availability of the CT results was measured with Cohen's kappa coefficient. Differences in selected treatments with or without accessibility to the CT results were plotted for the same endodontists using descriptive statistics. Results: The agreement in assessments among endodontists was slight or fair before the CT results were available (range: 0.081–0.535). No increase was observed after reviewing the CT results (range: 0.116–0.379). After the use of CT, the treatment plan was changed 38–76% of the time by all decision-makers, and the changes affected 57.8% of the cases in the study. Conclusions: The endodontists in this study exhibited a low degree of agreement when choosing a treatment for root-filled maxillary molars with apical periodontitis. A CT examination of the investigated teeth did not result in a significantly higher degree of agreement, and CT frequently contributed to a shift in the selected therapy. PMID:26985980

Periapical and endodontic status of type 2 diabetic patients in Catalonia, Spain: a cross-sectional study.

PubMed

López-López, José; Jané-Salas, Enric; Estrugo-Devesa, Albert; Velasco-Ortega, Eugenio; Martín-González, Jenifer; Segura-Egea, Juan José

2011-05-01

The aim of this study was to investigate radiographically the prevalence of apical periodontitis (AP) and endodontic treatment in a sample of adult type II diabetic patients and control subjects. In a cross-sectional study, the radiographic records of 50 adult patients reporting a history of well-controlled type 2 diabetes mellitus (DM) (study group) and 50 age- and sex-matched subjects who reported no history of DM (control group) were examined. Periapical status of all teeth was assessed using the periapical index score. The average number of teeth per patient in the diabetic and control groups was 21.9 and 24.6 teeth, respectively (P = .012). AP in one or more teeth was found in 37 diabetic patients (74%) and in 21 control subjects (42%) (odds ratio = 3.9, P = .002). One or more root-filled teeth were found in 35 (70%) and 25 (50%) of diabetic and control subjects, respectively (odds ratio = 2.3, P = .043). Among diabetic patients with root-filled teeth, 16 (46%) had AP affecting at least one treated tooth. Among controls with root-filled teeth, 6 (24%) had AP affecting at least one treated tooth (P > .05). Adjusting for teeth number, multivariate logistic regression analysis showed that periapical status (odds ratio = 3.3, P = .0071) and the number of root-filled teeth (odds ratio = 1.7; P = .0035) were significantly associated with diabetic status. The results showed that in adult patients, type 2 DM is significantly associated with an increased prevalence of AP and endodontic treatment. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Apical extrusion of debris by supplementary files used for retreatment: An ex vivo comparative study

PubMed Central

Pawar, Ajinkya M.; Pawar, Mansing; Metzger, Zvi; Thakur, Bhagyashree

2016-01-01

Aim: This study evaluated whether using supplementary files for removing root canal filling residues after ProTaper Universal Retreatment files (RFs) increased the debris extrusion apically. Materials and Methods: Eighty mandibular premolars with single root and canal were instrumented with ProTaper Universal rotary system (SX-F3) and obturated. The samples were divided randomly into four groups (n = 20). Group 1 served as a control; only ProTaper Universal RFs D1–D3 were used, and the extruded debris was weighed. Groups 2, 3, and 4 were the experimental groups, receiving a twofold retreatment protocol: Removal of the bulk, followed by the use of supplementary files. The bulk was removed by RFs, followed by the use of ProTaper NEXT (PTN), WaveOne (WO), and Self-Adjusting File (SAF) for removal of the remaining root filling residues. Debris extruded apically were weighed and compared to the control group. Statistical analysis was performed using one-way analysis of variance (ANOVA) and post hoc Tukey's test. Results: All the three experimental groups presented significant difference (P < .01). The post hoc Tukey's test confirmed that Group 4 (SAF) exhibited significantly less (P < .01) debris extrusion between the three groups tested. Conclusion: SAF results in less extrusion of debris when used as supplementary file to remove root-filling residues, compared to WO and PTN. PMID:27099416

Histologic evaluation of the effect of mineral trioxide aggregate-Fillapex as a root canal sealer in rat teeth submitted to late replantation

PubMed Central

Ferreira, Manuel Marques; Botelho, Maria Filomena; Abrantes, Margarida; Carvalho, Lina; Carrilho, Eunice

2017-01-01

Objective: This study aims to analyze the effect of new root canal based silicate cement, in rat teeth after late replantation, comparing with calcium hydroxide (CH) in preventing tooth root resorption. Materials and Methods: The study group included 16 Wistar rats in which the upper right central incisors were extracted and were left on a worktable for 60 min, simulating a case of tooth avulsion, after had been anesthetized. One group, (Group I), the canals were filled with CH past, before replantation. The second groups of teeth, (Group II), the canals were filled with mineral trioxide aggregate-Fillapex (MTAF). After removal, the blood clot of the socket, with saline solution irrigation, the teeth were replanted into their original socket, and splinted with silk 3/0. The rats were sacrificed 8 weeks after replantation and the specimens were prepared for histologic and histomorphometric analyses. The areas of inflammatory and replacement resorptions were selected and quantified. These data for each group of teeth were evaluated and analyzed using the Mann–Whitney test (P = 0.05). Result and Conclusion: All the replanted teeth in both groups survived. Although root canal filled with MTAF provide better results than with CH past concerning inflammatory and replacement resorption, there was no statistical difference (P = 0.527). PMID:28435372

Soft chelating irrigation protocol optimizes bonding quality of Resilon/Epiphany root fillings.

PubMed

De-Deus, Gustavo; Namen, Fátima; Galan, João; Zehnder, Matthias

2008-06-01

This study was designed to test the impact of either a strong (MTAD) or a soft (1-hydroxyethylidene-1, 1-bisphosphonate [HEPB]) chelating solution on the bond strength of Resilon/Epiphany root fillings. Both 17% EDTA and the omission of a chelator in the irrigation protocol were used as reference treatments. Forty extracted human upper lateral incisors were prepared using different irrigation protocols (n = 10): G1: NaOCl, G2: NaOCl + 17% EDTA, G3: NaOCl + BioPure MTAD (Dentsply/Tulsa, Tulsa, OK), and G4: NaOCl + 18% HEPB. The teeth were obturated and then prepared for micropush-out assessment using root slices of 1 mm thickness. Loading was performed on a universal testing machine at a speed of 0.5 mm/min. One-way analysis of variance and Tukey multiple comparisons were used to compare the results among the experimental groups. EDTA- and MTAD-treated samples revealed intermediate bond strength (0.3-3.6 MPa). The lowest bond strengths were achieved in NaOCl-treated samples (0.3-1.2 MPa, p < 0.05). The highest bond strength was reached in the HEBP-treated samples (3.1-6.1 MPa, p < 0.05). Under the present in vitro conditions, the soft chelating irrigation protocol (18% HEBP) optimized the bonding quality of Resilon/Epiphany (Resilon Research LLC, Madison, CT) root fillings.

[Evaluation of pH variation and cervical dentin permeability in teeth submitted to bleaching treatment].

PubMed

Dezotti, Mariela S G; Souza, Mário Honorato Silva e; Nishiyama, Celso Kenji

2002-01-01

External cervical root resorption is one of the disadvantages of the bleaching procedure. There are several mechanisms that may be responsible for causing resorption, such as the chemical and physical action of the utilized materials and the morphology of the cementoenamel junction. The purpose of this study was to investigate the presence of a communication between the pulp chamber and the external root surface. The investigation was carried out by means of pH tests and measurement of dye infiltration into cervical dentin after the bleaching procedure. Thirty-four human permanent incisors were submitted to endodontic treatment. The teeth were assigned to three experimental groups, according to the level at which the filling was cut, and to the sealing of the root canal entrance with glass ionomer cement. Sodium perborate and 30% hydrogen peroxide were utilized for bleaching. pH readings were carried out after 30 minutes, 24 h, 48 h and 72 h from the beginning of the procedure. The teeth were immersed in 0.5% basic fuchsin for 24 h in order to determine possible differences in the permeability of cervical dentin. The results revealed that pH tended to change when the root filling was cut at the entrance of the canal, when 2 mm of the filling were removed, and when the canal entrance was sealed with glass ionomer. Dentinal permeability increased in the three experimental groups, in comparison with the control group. These slight differences may suggest a communication between the pulp chamber and the external root surface.

Impact of three radiographic methods in the outcome of nonsurgical endodontic treatment: a five-year follow-up.

PubMed

Fernández, Rafael; Cadavid, Diego; Zapata, Sandra M; Alvarez, Luis G; Restrepo, Felipe A

2013-09-01

The periapical film radiograph (PFR) and digital periapical radiograph (DPR) techniques have some limitations in the visualization of small periapical lesions (PLs) when compared with cone-beam computed tomography (CBCT). However, the evidence supporting their effectiveness is very limited. This retrospective longitudinal cohort study evaluated the outcome of endodontic treatments measured/monitored by PFR, DPR, and CBCT during a 5-year follow-up and also determined the prognostic factors that influenced treatment success. A total of 132 teeth (208 roots) with vital pulps received endodontic treatment. The periapical indexes with scores ≥2 for PFR and DPR and ≥1 for CBCT indicated the presence of PLs. Prognostic factors were determined by bivariate and multivariate analyses. Statistical significance was defined at a P level <.05. CBCT detected a higher number of PLs (18.7%, n = 39 roots), followed by DPR (7.7%, n = 16 roots) and PFR (5.7%, n = 12 roots). Likewise, CBCT was more sensitive than PFR and DPR in detecting deficiencies in extension and density of the root canal filling (P ≤ .001). Of the 17 prognostic factors evaluated, 4 were significantly associated with poor outcome to the treatment (P < .05): root canal curvature, disinfection of gutta-percha, presence of missed canals, and the quality of definitive coronal restoration. The success outcome of endodontic treatment after 5 years in teeth with vital pulps varied with each radiographic method: 94.3%/PFR, 92.3%/DPR, and 81.3%/CBCT. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Evaluation of fracture resistance in simulated immature teeth using Resilon and Ribbond as root reinforcements--an in vitro study.

PubMed

Hemalatha, Hiremath; Sandeep, Metgud; Kulkarni, Sadanand; Yakub, Shoeb Sheikh

2009-08-01

To compare the reinforcement and strengthening ability of resilon, gutta-percha, and ribbond in endodontically treated roots of immature teeth. Sixty five freshly extracted human maxillary anterior teeth were prepared with a Peeso no. 6 to simulate immature teeth (Cvek's stage 3 root development). After instrumentation, each root was irrigated with sodium hypochlorite and with ethylene diamino tetra acetic acid to remove the smear layer. To simulate single visit apexification technique a 4-5 mm white Pro Root mineral trioxide aggregate plug was placed apically using schilder carrier. The teeth were divided into three experimental groups and one control group. Group I--control group (root canals instrumented but not filled); Group II--backfilled with thermoplastisized gutta-percha using AH plus sealer; Group III--reinforced with Resilon using epiphany sealer; Group IV--reinforced with Ribbond fibers using Panavia F luting cement. A Universal Testing Machine was used to apply a load, at the level of the lingual cementoenamel junction with a chisel-shaped tip The peak load to fracture was recorded and statistical analysis was completed using student's t-test. Values of peak load to fracture were 1320.8, 1604.88, 1620, and 1851 newtons for Group I to Group IV respectively. The results of student's t-test, revealed no significant difference (P > 0.05,) between Group II and Group III. Comparison between Group IV and Group III and between Group IV and Group II revealed highly significant difference (P > 0.001). Teeth reinforced with Ribbond fibers using Panavia F luting cement showed the highest resistance to fracture. Resilon could not strengthen the roots and showed no statistically significant difference when compared with thermoplastisized gutta-percha in reinforcing immature tooth when tested with universal testing machine in an experimental model of immature tooth.

Capillary-Effect Root-Environment System

NASA Technical Reports Server (NTRS)

Wright, Bruce D.

1991-01-01

Capillary-effect root-environment system (CERES) is experimental apparatus for growing plants in nutrient solutions. Solution circulated at slight tension in cavity filled with plastic screen and covered by porous plastic membrane. By adsorptive attraction, root draws solution through membrane. Conceived for use in microgravity of space, also finds terrestrial application in germinating seedlings, because it protects them from extremes of temperature, moisture, and soil pH and from overexposure to fertilizers and herbicides.

Improving Marine Corps Assignment of SDAP Levels

DTIC Science & Technology

2013-03-01

Nettles , Colonel, USMC, M&RA (MPO). 15 Information Paper SDAP. 17 for a job or being able to fill the position at all, in addition to the potential to...Total 7850672.93 60132 130.557323 Root MSE = 6.2241... Root MSE = .26638 Adj R-squared = 0.0097 Residual 4577.29534 64507 .070958118

Carbon Nanotubes Filled with Different Ferromagnetic Alloys Affect the Growth and Development of Rice Seedlings by Changing the C:N Ratio and Plant Hormones Concentrations.

PubMed

Hao, Yi; Yu, Feifan; Lv, Ruitao; Ma, Chuanxin; Zhang, Zetian; Rui, Yukui; Liu, Liming; Cao, Weidong; Xing, Baoshan

2016-01-01

The aim of this study was to investigate the phytotoxicity of thin-walled carbon nanotubes (CNTs) to rice (Oryza sativa L.) seedlings. Three different CNTs, including hollow multi-walled carbon nanotubes (MWCNTs), Fe-filled carbon nanotubes (Fe-CNTs), and Fe-Co-filled carbon nanotubes (FeCo-CNTs), were evaluated. The CNTs significantly inhibited rice growth by decreasing the concentrations of endogenous plant hormones. The carbon to nitrogen ratio (C:N ratio) significantly increased in rice roots after treatments with CNTs, and all three types of CNTs had the same effects on the C:N ratio. Interestingly, the increase in the C:N ratio in roots was largely because of decreased N content, indicating that the CNTs significantly decreased N assimilation. Analyses of the Fe and Co contents in plant tissues, transmission electron microscope (TEM) observations and energy dispersive X-ray spectroscopy (EDS) analysis proved that the CNTs could penetrate the cell wall and the cell membrane, and then enter the root cells. According to the author's knowledge, this is the first time to study the relationship between carbon nanotubes and carbon nitrogen ratio and plant hormones.

The outcome of apical microsurgery using MTA as the root-end filling material: 2- to 6-year follow-up study.

PubMed

Çalışkan, M K; Tekin, U; Kaval, M E; Solmaz, M C

2016-03-01

To evaluate the influence of various predictors on the healing outcome 2-6 years after apical microsurgery (AMS) using MTA as the root-end filling material. A total of 90 anterior teeth with asymptomatic persistent periradicular periodontitis of strictly endodontic origin that failed after either nonsurgical or surgical treatment were included. Surgery was completed under local anaesthesia using a standardized clinical protocol. Clinical and radiographic measures as well as the follow-up period were used to determine the healing outcome. For statistical analysis of the predictors, the outcome was dichotomized into healed cases and nonhealed cases. Odds ratios were calculated, and Pearson chi-square or Fisher's exact tests were used to analyse the data. Clinical and radiographic assessment of AMS revealed that 80% were healed, 14.4% were nonhealed, whilst 5.6% were judged to be uncertain. None of the various predictors investigated had a significant influence on the outcome of AMS. The results of this clinical study demonstrated that 80% of cases that received apical microsurgery healed when using MTA as the root-end filling material. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Carbon Nanotubes Filled with Different Ferromagnetic Alloys Affect the Growth and Development of Rice Seedlings by Changing the C:N Ratio and Plant Hormones Concentrations

PubMed Central

Lv, Ruitao; Ma, Chuanxin; Zhang, Zetian; Rui, Yukui; Liu, Liming; Cao, Weidong; Xing, Baoshan

2016-01-01

The aim of this study was to investigate the phytotoxicity of thin-walled carbon nanotubes (CNTs) to rice (Oryza sativa L.) seedlings. Three different CNTs, including hollow multi-walled carbon nanotubes (MWCNTs), Fe-filled carbon nanotubes (Fe-CNTs), and Fe-Co-filled carbon nanotubes (FeCo-CNTs), were evaluated. The CNTs significantly inhibited rice growth by decreasing the concentrations of endogenous plant hormones. The carbon to nitrogen ratio (C:N ratio) significantly increased in rice roots after treatments with CNTs, and all three types of CNTs had the same effects on the C:N ratio. Interestingly, the increase in the C:N ratio in roots was largely because of decreased N content, indicating that the CNTs significantly decreased N assimilation. Analyses of the Fe and Co contents in plant tissues, transmission electron microscope (TEM) observations and energy dispersive X-ray spectroscopy (EDS) analysis proved that the CNTs could penetrate the cell wall and the cell membrane, and then enter the root cells. According to the author's knowledge, this is the first time to study the relationship between carbon nanotubes and carbon nitrogen ratio and plant hormones. PMID:27284692

Effects of different radio-opacifying agents on physicochemical and biological properties of a novel root-end filling material

PubMed Central

Lü, Xiao-Ying; Liu, Gen-Di

2018-01-01

Background/Purpose Radio-opacity is an essential attribute of ideal root-end filling materials because it is important for clinicians to observe root canal filling and to facilitate the follow-up instructions. The novel root-end filling material (NRFM) has good cytocompatibility and physicochemical properties but low intrinsic radio-opacity value. To improve its radio-opacity value, three novel radio-opaque root-end filling materials (NRRFMs) were developed by adding barium sulphate (NRFM-Ba), bismuth trioxide (NRFM-Bi) and zirconium dioxide (NRFM-Zr) to NRFM, respectively. The purpose of this study was to identify the suitable radio-opacifier for NRFM through evaluating their physicochemical and biological properties, in comparison with NRFM and glass ionomer cement (GIC). Methods NRRFMs were characterized using X-ray diffraction (XRD) and Fourier transform infrared spectrophotometry (FTIR). Physicochemical properties including setting time, compressive strength, porosity, pH variation, solubility, washout resistance, contact angle and radiopacity were investigated. Cytocompatibility of both freshly mixed and set NRRFMs was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Alkaline phosphatase (ALP) activity assay and alizarin red staining were used to investigate the osteogenic differentiation potential of NRFM-Zr. Data were analyzed using two-way ANOVA (pH variation, solubility and ALP activity) and one-way ANOVA (for the other variables). Results (1) NRRFMs were primarily composed of hydroxyapatite, calcium carboxylate salt and the corresponding radio-opacity agents (barium sulphate, bismuth trioxide or zirconium dioxide). (2) Besides similar physicochemical properties in terms of setting time, pH variation, solubility, washout resistance and contact angle to NRFM, NRFM-Bi and NRFM-Zr exhibited lower porosity and greater compressive strength after being set for 7 days and their radio-opacity were greater than the 3 mm aluminium thickness specified in ISO 6876 (2001). (3) MTT assay revealed that freshly mixed and set NRFM-Zr presented better cell viability than NRFM-Ba and NRFM-Bi at 24 hours and 48 hours (P<0.05). (4) NRFM-Zr significantly enhanced ALP activity and calcium formation of human osteoblast-like Saos-2 cells when compared with negative group and GIC (P<0.05). Conclusion NRFM-Zr presents desirable physicochemical and biological properties, thus zirconium dioxide may be a suitable radio-opacifier for NRFM. PMID:29420559

Effects of different radio-opacifying agents on physicochemical and biological properties of a novel root-end filling material.

PubMed

Chen, Yao-Zhong; Lü, Xiao-Ying; Liu, Gen-Di

2018-01-01

Radio-opacity is an essential attribute of ideal root-end filling materials because it is important for clinicians to observe root canal filling and to facilitate the follow-up instructions. The novel root-end filling material (NRFM) has good cytocompatibility and physicochemical properties but low intrinsic radio-opacity value. To improve its radio-opacity value, three novel radio-opaque root-end filling materials (NRRFMs) were developed by adding barium sulphate (NRFM-Ba), bismuth trioxide (NRFM-Bi) and zirconium dioxide (NRFM-Zr) to NRFM, respectively. The purpose of this study was to identify the suitable radio-opacifier for NRFM through evaluating their physicochemical and biological properties, in comparison with NRFM and glass ionomer cement (GIC). NRRFMs were characterized using X-ray diffraction (XRD) and Fourier transform infrared spectrophotometry (FTIR). Physicochemical properties including setting time, compressive strength, porosity, pH variation, solubility, washout resistance, contact angle and radiopacity were investigated. Cytocompatibility of both freshly mixed and set NRRFMs was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Alkaline phosphatase (ALP) activity assay and alizarin red staining were used to investigate the osteogenic differentiation potential of NRFM-Zr. Data were analyzed using two-way ANOVA (pH variation, solubility and ALP activity) and one-way ANOVA (for the other variables). (1) NRRFMs were primarily composed of hydroxyapatite, calcium carboxylate salt and the corresponding radio-opacity agents (barium sulphate, bismuth trioxide or zirconium dioxide). (2) Besides similar physicochemical properties in terms of setting time, pH variation, solubility, washout resistance and contact angle to NRFM, NRFM-Bi and NRFM-Zr exhibited lower porosity and greater compressive strength after being set for 7 days and their radio-opacity were greater than the 3 mm aluminium thickness specified in ISO 6876 (2001). (3) MTT assay revealed that freshly mixed and set NRFM-Zr presented better cell viability than NRFM-Ba and NRFM-Bi at 24 hours and 48 hours (P<0.05). (4) NRFM-Zr significantly enhanced ALP activity and calcium formation of human osteoblast-like Saos-2 cells when compared with negative group and GIC (P<0.05). NRFM-Zr presents desirable physicochemical and biological properties, thus zirconium dioxide may be a suitable radio-opacifier for NRFM.

A new method to enhance rhizosheath formation

NASA Astrophysics Data System (ADS)

Ahmadi, katayoun; Zarebanadkouki, Mohsen; Kuzyakov, Yakov; Carminati, Andrea

2016-04-01

The rhizosheath is defined as the soil that adheres to the roots by help of root hairs and mucilage. Rhizosheath maintain the contact between roots and soil improving water and nutrient uptake. Here we introduce: (1) a technique to quantify the formation of rhizosheath around the roots, and (2) a method to enhance the formation of rhizosheath around the roots. Additionally, we measured the relation between rhizosheath thickness and the carbon content and enzyme activities in the rhizosphere. We grew lupine plants in aluminum containers (28×30×1 cm) filled with a sandy soil. When plants were two weeks-old and the soil had a water content of 30%, we stopped the irrigation and let the plants to uptake water to a soil water content of 4-5%. Thereafter, half of the plants (4 plants) were irrigated with water and the other half with water with an additive (international patent is pending). We repeated the drying and rewetting cycle three times. At the end of the third drying cycle, when plants were 40 days old and soil had a water content of 4-5%,the containers were opened and roots and their surrounding soils were gently collected. We used imaging to quantify the rhizosheath formation. The method consists of scanning the roots and the surrounding soil using the Winrhizo software. By image analysis we quantified the thickness of roots and their rhizosheath. The plants irrigated with the additive had 63% thicker rhizopsheath than plants irrigated with water. So, the additive enhanced gelation of mucilage exuded by the roots. Carbon content and enzyme activity in the collected rhizosheath showed that the rhizosheath of plants irrigated with the additive had higher carbon content and enzyme activity than the rhizopsheath of plants irrigated with water. The new method to increase rhizosheath has the great advantage that can be easily applied to the irrigation water to improve plant uptake of water and nutrients in semiarid and arid areas.

Effect of the fungus Piriformospora indica on physiological characteristics and root morphology of wheat under combined drought and mechanical stresses.

PubMed

Hosseini, Fatemeh; Mosaddeghi, Mohammad Reza; Dexter, Anthony Roger

2017-09-01

This study was done to evaluate the effects of the root-colonizing endophytic fungus Piriformospora indica on wheat growth under combined drought and mechanical stresses. Inoculated (colonized) and non-inoculated (uncolonized) wheat (Triticum aestivum L. cv. Chamran) seedlings were planted in growth chambers filled with moist sand (at a matric suction of 20 hPa). Slight, moderate and severe mechanical stresses (i.e., penetration resistance, Q p , of 1.17, 4.17 and 5.96 MPa, respectively) were produced by a dead-load technique (i.e., placing a weight on the sand surface) in the root medium. Slight, moderate and severe drought stresses were induced using PEG 6000 solutions with osmotic potentials of 0, -0.3 and -0.5 MPa, respectively. After 30 days, plant physiological characteristics and root morphology were measured. An increase in Q p from 1.17 to 5.96 MPa led to greater leaf proline concentration and root diameter, and lower relative water content (RWC), leaf water potential (LWP), chlorophyll contents and root volume. Moreover, severe drought stress decreased root and shoot fresh weights, root volume, leaf area, RWC, LWP and chlorophyll content compared to control. Catalase (CAT) and ascorbate peroxidase (APX) activities under severe drought stress were about 1.5 and 2.9 times greater than control. Interaction of the stresses showed that mechanical stress primarily controls plant water status and physiological responses. However, endophyte presence mitigated the adverse effects of individual and combined stresses on plant growth. Colonized plants were better adapted and had greater root length and volume, RWC, LWP and chlorophyll contents under stressful conditions due to higher absorption sites for water and nutrients. Compared with uncolonized plants, colonized plants showed lower CAT activity implying that wheat inoculated with P. indica was more tolerant and experienced less oxidative damage induced by drought and/or mechanical stress. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

An In-Vitro Evaluation and Comparison of Apical Sealing Ability of Three Different Obturation Technique - Lateral Condensation, Obtura II, and Thermafil.

PubMed

Emmanuel, Samson; Shantaram, Kulkarni; Sushil, Kumar C; Manoj, Likhitkar

2013-04-01

Success of non-surgical root canal treatment is predicted by meticulous cleaning and shaping of the root canal system, three-dimensional obturation and a well-fitting "leakage-free" coronal restoration. The techniques of obturation that are available have their own relative position in the historical development of filling techniques. Over the years, pitfalls with one technique have often led to the development of newer methods of obturation, along with the recognition that no one method of obturation may satisfy all clinical cases. A total of 120 extracted human permanent anterior maxillary and mandibular single rooted teeth were selected for the present study and divided into 3 groups based on the method of obturation technique. Following the preparation the patency at the apical foramen was confirmed by passing a file #15. After obturation of all three groups, teeth were immersed in 1% of aqueous methylene blue dye for a period of two weeks and then samples were subjected to spectrophotometric analysis. The present study was conducted to evaluate in vitro the spectrophotometric analysis to quantitatively analyze relative amount of dye penetration using lateral condensation (Group I), Obtura II (Group II ), Thermafil obturating technique (Group III) with ZOE sealer used in all groups. Teeth obturated with lateral condensation (Group I) shows mean value of 0.0243 and standard deviation of 0.0056. The Group II thermoplasticized injectable moulded Guttapercha (Obtura II) showed 0.0239 mean and standard deviation value of 0.0045 and Group III Thermafil obturation technique shows 0.0189 as mean value and 0.0035 standard deviation values. Following conclusion was drawn from the present study. Group III i.e., Thermafil obturating technique shows minimum mean apical dye penetration compared to Group II (ObturaII) and Group I (lateral condensation).Lateral condensation shows maximum mean apical dye penetration in all three groups.There is no significant difference between the apical dye penetration of lateral condensation and Obtura II. Obturation, lateral condensation, Obtura II, Thermafil, Spectrophotometer, dye penetration. How to cite this article: Samson E, Kulkarni S, Sushil K C, Likhitkar M. An In-Vitro Evaluation and Comparison of Apical Sealing Ability of Three Different Obturation Technique - Lateral Condensation, Obtura II, and Thermafil. J Int Oral Health 2013; 5(2):35-43.

The use of mineral trioxide aggregate in endodontics.

PubMed

Casella, G; Ferlito, S

2006-03-01

Mineral trioxide aggregate (MTA), composed mainly of tricalcic silicate, tricalcic alluminate, bismuth oxide, is a particular endodontic cement. It is made of hydrophilic fine particles that harden in the presence of dampness or blood. It is biocompatible, radiopaque and it is harder to infiltrate, compared to classic materials for root filling such as amalgam, cements, Super-EBA, and IRM. and SEM studies of sections and copies in resin of root neoapices filled with amalgam, IRM, Super-EBA and MTA, as well as tests of microinfiltration have shown that MTA has excellent sealing capacities. It requires a working time of about 5 min and a hardening time that varies from 2 h and 45 min to 4 h according to the density of the air entrapped during mixing and the dampness of the receiving site. The long hardening time reduces internal tensions and the incidence of marginal infiltration, but it forces to definitively fill the tooth in the following sitting, with an interval of at least 3 days from the MTA application. Clinical experience shows how MTA is a material of choice in cases not only of endodontic surgery, apicectomy and retrograde filling but also in the sealing filling of perforations of the pulp chamber and of the root, stripping, internal reabsorptions, readaptations, lacerations, and apical transports. It has been used with success also in direct cappings and in apexifications instead of calcium hydroxide, leading to quicker therapies and more predictable The authors outline the operative phases of the different treatments proposed, make a survey of the most important studies published so far and hope that a new sealing cement with more reduced hardening times will soon be available.

Reaction of the lateral periodontium of dogs' teeth to contaminated and noncontaminated perforations filled with mineral trioxide aggregate.

PubMed

Holland, Roberto; Bisco Ferreira, Luciana; de Souza, Valdir; Otoboni Filho, José Arlindo; Murata, Sueli Satomi; Dezan, Eloi

2007-10-01

It has been shown that the mineral trioxide aggregate (MTA) used to seal lateral/furcal perforations stimulates the deposition of newly formed cementum. Nevertheless, when the site of the perforation is contaminated, the healing process might occur under less favorable conditions. This study evaluated the repair healing process of noncontaminated and contaminated lateral perforations filled with MTA and the effect of previously filling the contaminated perforations with a bactericidal agent. Thirty lateral root perforations were prepared in endodontically treated dog's teeth, thus forming 3 groups with 10 specimens each. In group 1 the perforations were immediately sealed with MTA. In group 2 the perforations were left open for 7 days and thereafter sealed with MTA. In group 3 the perforations were left open for 7 days, filled temporarily with a calcium hydroxide-based paste for 14 days, and then sealed with MTA. The animals were killed after 90 days, and the pieces were prepared for histomorphologic and histomicrobiologic evaluations. The statistical analysis showed that group 1 had significantly better repair than groups 2 (P < .05) and 3 (P < .05), which validates the superior results obtained when MTA was immediately used to seal root perforations. Groups 2 and 3 had statistically similar repair to each other (P > .05). There were a larger number of cases of complete or partial biologic seal in group 1 compared with the contaminated groups. It might be concluded that the lateral root perforations sealed with MTA after contamination presented worse repair than the noncontaminated, immediately sealed perforations. The temporary filling with a bactericidal agent (calcium hydroxide-based paste) did not improve the repair of perforations exposed to contamination, and the contaminated groups presented similar results to each other.

Maxillary first molar with an O-shaped root morphology: report of a case.

PubMed

Shin, Yooseok; Kim, Yemi; Roh, Byoung-Duck

2013-12-01

This case report is to present a maxillary first molar with one O-shaped root, which is an extended C-shaped canal system. Patient with chronic apical periodontitis in maxillary left first molar underwent replantation because of difficulty in negotiating all canals. Periapical radiographs and cone-beam computed tomography (CBCT) were taken. All roots were connected and fused to one root, and all canals seemed to be connected to form an O-shape. The apical 3 mm of the root were resected and retrograde filled with resin-modified glass ionomer. Intentional replantation as an alternative treatment could be considered in a maxillary first molar having an unusual O-shaped root.

Perforating internal root resorption repaired with mineral trioxide aggregate caused complete resolution of odontogenic sinus mucositis: a case report.

PubMed

Bendyk-Szeffer, Maja; Łagocka, Ryta; Trusewicz, Matylda; Lipski, Mariusz; Buczkowska-Radlińska, Jadwiga

2015-02-01

An extensive perforating internal root resorption accompanied by apical periodontitis and odontogenic sinus mucositis was detected on preoperative cone-beam computed tomographic scans in a first maxillary molar. After the chemomechanical debridement of the root canals, calcium hydroxide was placed as a temporary dressing for 7 days. Mineral trioxide aggregate was used to fill the perforation site with the aid of a surgical microscope. At the next visit, the root with the resorption defect was filled with warm vertical compaction of gutta-percha. A control cone-beam computed tomographic scan acquired 6 months after the endodontic treatment revealed complete resolution of the sinus retention cyst. Moreover, the patient's frequent otolaryngologic disturbances ceased. The tooth was functional with satisfactory clinical and radiographic results after 12 months. Based on the results of this case, successful repair of an extensive, perforating internal resorption with mineral trioxide aggregate may lead to complete resolution of apical periodontitis and maxillary sinus retention cyst. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The effect of retreatment procedure on the pH changes at the surface of root dentin using two different calcium hydroxide pastes

PubMed Central

Kazemipoor, Maryam; Tabrizizadeh, Mehdi; Dastani, Milad; Hakimian, Roqayeh

2012-01-01

Aim: To compare pH changes at the cervical, middle and apical surfaces of root dentin in retreated and non- retreated teeth, after canal obturation with two different calcium hydroxide pastes. Materials and Methods: After instrumentation of 55 extracted teeth, three cavities with 0.75 mm depth and 1.5 mm in diameter were drilled at buccal root surface. The teeth were randomly divided into five groups. Canals in the first two groups were filled with either mixture of calcium hydroxide and saline solution and calcium hydroxide and 2% chlorhexidine (CHX). In the third and fourth groups canals were first obturated with gutta-percha and AH26 sealer, and then materials were removed. After 2 days canals were filled with two different calcium hydroxide pastes similar to the first and the second groups. The pH was measured in the prepared cavities at 1, 3, 7 and 14 days. Results: In the non-retreated groups, pH at the surface of the roots was significantly higher in comparison to the retreated ones (P value < 0.001). pH values were significantly higher in the non-retreated teeth filling with calcium hydroxide and saline solution (P value < 0.001). Conclusion: Regarding to the little pH changes at the surface of dentin in retreated teeth, the hydroxyl ions cannot penetrate into the dentinal tubules. Thus, to achieve higher pH at the root surface in retreated teeth, it is clinically advisable to remove more dentin from the inner walls and to use normal saline as a vehicle for calcium hydroxide rather than acidic pH materials. PMID:23112482

The effect of retreatment procedure on the pH changes at the surface of root dentin using two different calcium hydroxide pastes.

PubMed

Kazemipoor, Maryam; Tabrizizadeh, Mehdi; Dastani, Milad; Hakimian, Roqayeh

2012-10-01

To compare pH changes at the cervical, middle and apical surfaces of root dentin in retreated and non- retreated teeth, after canal obturation with two different calcium hydroxide pastes. After instrumentation of 55 extracted teeth, three cavities with 0.75 mm depth and 1.5 mm in diameter were drilled at buccal root surface. The teeth were randomly divided into five groups. Canals in the first two groups were filled with either mixture of calcium hydroxide and saline solution and calcium hydroxide and 2% chlorhexidine (CHX). In the third and fourth groups canals were first obturated with gutta-percha and AH26 sealer, and then materials were removed. After 2 days canals were filled with two different calcium hydroxide pastes similar to the first and the second groups. The pH was measured in the prepared cavities at 1, 3, 7 and 14 days. In the non-retreated groups, pH at the surface of the roots was significantly higher in comparison to the retreated ones (P value < 0.001). pH values were significantly higher in the non-retreated teeth filling with calcium hydroxide and saline solution (P value < 0.001). Regarding to the little pH changes at the surface of dentin in retreated teeth, the hydroxyl ions cannot penetrate into the dentinal tubules. Thus, to achieve higher pH at the root surface in retreated teeth, it is clinically advisable to remove more dentin from the inner walls and to use normal saline as a vehicle for calcium hydroxide rather than acidic pH materials.

Comparative in vivo analysis of the sealing ability of three endodontic sealers in post-prepared root canals.

PubMed

Kopper, P M P; Figueiredo, J A P; Della Bona, A; Vanni, J R; Bier, C A; Bopp, S

2003-12-01

To compare the sealing ability of the endodontic sealers AH Plus, Sealer 26 and Endofill in premolar teeth of dogs exposed to the oral cavity after post-preparation. Forty teeth with two canals each underwent root canal cleaning and shaping. Before filling, the canals were randomly distributed into three groups according to the sealer to be used: Group 1 - AH Plus; Group 2 - Sealer 26; and Group 3 - Endofill (Dentsply, Indústria e Comércio Ltda.). Immediately after filling, the gutta percha and sealer were partially removed from the canals, leaving material only in the apical third of the root. The teeth were temporarily sealed with glass ionomer sealer for 72 h to ensure setting. The coronal seal was then removed and the canals were exposed to the oral cavity for 45 days. The animals were euthanased and their mandibles and maxillae were removed. After abundant irrigation with distilled water, the canals were dried and filled with India ink. The teeth were sealed again for 96 h before extraction. The roots of the extracted premolars were separated and stored in labelled test tubes. The roots were cleared and the extent of dye penetration was measured with a 20x stereoscopic magnifying lens. Statistical analysis revealed that there were significant differences between the sealers studied (P < 0.001). Means for the extent of dye penetration for AH Plus, Endofill and Sealer 26 were, respectively, 0.13, 2.27 and 3.08 mm. After 45 days exposure to the oral cavity, none of the sealers was capable of preventing leakage and coronal dye penetration. There were significant differences between the sealers studied, in terms of mean dye penetration.

An in vitro study of coronal leakage after intraradicular preparation of cast-dowel space.

PubMed

Pappen, A F; Bravo, M; Gonzalez-Lopez, S; Gonzalez-Rodriguez, M P

2005-09-01

Coronal leakage can produce contamination of periapical tissues, resulting in endodontic failure. The purpose of this in vitro study was to evaluate the ability of 2 sealers to prevent coronal leakage in canals filled with gutta-percha and prepared for cast dowels but without coronal sealing. The crowns of 60 extracted single-rooted teeth were amputated. The root canals were prepared corono-apically and filled with gutta-percha cones and 1 of 2 different endodontic sealers: a resin-based sealer (AH Plus) and a calcium hydroxide-based sealer (Sealapex). Specimens were then stored in water for 7 days to allow the sealers to set. The specimens were prepared in 1 of 2 ways: no preparation for cast dowel or preparation of cast-dowel space (n=15). External surfaces of the roots were sealed with cyanoacrylate cement. The teeth were thermal cycled at 5 degrees and 55 degrees C in water baths (dwell time=30 seconds) for 500 cycles. Specimens were then submerged in 2% methylene blue colorant for 24 hours. Microleakage was measured according to the percentage of area stained with the colorant. Effects of each factor (cast-dowel preparation and type of sealant) on microleakage were analyzed by the Student t test (alpha=.05). The AH Plus and Sealapex sealers with cast-dowel preparation resulted in significantly (P<.001) more leakage compared to sealers with no dowel preparation. Cast dowel-space preparation had a negative influence on the sealing ability of the remnant root-canal filling material.

Solubility and bacterial sealing ability of MTA and root-end filling materials.

PubMed

Espir, Camila Galletti; Guerreiro-Tanomaru, Juliane Maria; Spin-Neto, Rubens; Chávez-Andrade, Gisselle Moraima; Berbert, Fabio Luiz Camargo Villela; Tanomaru-Filho, Mario

2016-04-01

Objective To evaluate solubility and sealing ability of Mineral Trioxide Aggregate (MTA) and root-end filling materials. Material and Methods The materials evaluated were: MTA, Calcium Silicate Cement with zirconium oxide (CSC/ZrO2), and zinc oxide/eugenol (ZOE). Solubility test was performed according to ANSI/ADA. The difference between initial and final mass of the materials was analyzed after immersion in distilled water for 7 and 30 days. Retrograde cavities in human teeth with single straight root canal were performed by using ultrasonic tip CVD 9.5107-8. The cavities were filled with the evaluated materials to evaluate sealing ability using the bacterial leakage test with Enterococcus faecalis. Bacterial leakage was evaluated every 24 hours for six weeks observing the turbidity of Brain Heart infusion (BHI) medium in contact with root apex. Data were submitted to ANOVA followed by Tukey tests (solubility), and Kruskal-Wallis and Dunn tests (sealing ability) at a 5% significance level. Results For the 7-day period, ZOE presented highest solubility when compared with the other groups (p<0.05). For the 30-day period, no difference was observed among the materials. Lower bacterial leakage was observed for MTA and CSC/ZrO2, and both presented better results than ZOE (p<0.05). Conclusion MTA and CSC/ZrO2 presented better bacterial sealing capacity, which may be related to lower initial solubility observed for these materials in relation to ZOE.

Route and Regulation of Zinc, Cadmium, and Iron Transport in Rice Plants (Oryza sativa L.) during Vegetative Growth and Grain Filling: Metal Transporters, Metal Speciation, Grain Cd Reduction and Zn and Fe Biofortification

PubMed Central

Yoneyama, Tadakatsu; Ishikawa, Satoru; Fujimaki, Shu

2015-01-01

Zinc (Zn) and iron (Fe) are essential but are sometimes deficient in humans, while cadmium (Cd) is toxic if it accumulates in the liver and kidneys at high levels. All three are contained in the grains of rice, a staple cereal. Zn and Fe concentrations in rice grains harvested under different levels of soil/hydroponic metals are known to change only within a small range, while Cd concentrations show greater changes. To clarify the mechanisms underlying such different metal contents, we synthesized information on the routes of metal transport and accumulation in rice plants by examining metal speciation, metal transporters, and the xylem-to-phloem transport system. At grain-filling, Zn and Cd ascending in xylem sap are transferred to the phloem by the xylem-to-phloem transport system operating at stem nodes. Grain Fe is largely derived from the leaves by remobilization. Zn and Fe concentrations in phloem-sap and grains are regulated within a small range, while Cd concentrations vary depending on xylem supply. Transgenic techniques to increase concentrations of the metal chelators (nicotianamine, 2′-deoxymugineic acid) are useful in increasing grain Zn and Fe concentrations. The elimination of OsNRAMP5 Cd-uptake transporter and the enhancement of root cell vacuolar Cd sequestration reduce uptake and root-to-shoot transport, respectively, resulting in a reduction of grain Cd accumulation. PMID:26287170

Route and Regulation of Zinc, Cadmium, and Iron Transport in Rice Plants (Oryza sativa L.) during Vegetative Growth and Grain Filling: Metal Transporters, Metal Speciation, Grain Cd Reduction and Zn and Fe Biofortification.

PubMed

Yoneyama, Tadakatsu; Ishikawa, Satoru; Fujimaki, Shu

2015-08-13

Zinc (Zn) and iron (Fe) are essential but are sometimes deficient in humans, while cadmium (Cd) is toxic if it accumulates in the liver and kidneys at high levels. All three are contained in the grains of rice, a staple cereal. Zn and Fe concentrations in rice grains harvested under different levels of soil/hydroponic metals are known to change only within a small range, while Cd concentrations show greater changes. To clarify the mechanisms underlying such different metal contents, we synthesized information on the routes of metal transport and accumulation in rice plants by examining metal speciation, metal transporters, and the xylem-to-phloem transport system. At grain-filling, Zn and Cd ascending in xylem sap are transferred to the phloem by the xylem-to-phloem transport system operating at stem nodes. Grain Fe is largely derived from the leaves by remobilization. Zn and Fe concentrations in phloem-sap and grains are regulated within a small range, while Cd concentrations vary depending on xylem supply. Transgenic techniques to increase concentrations of the metal chelators (nicotianamine, 2'-deoxymugineic acid) are useful in increasing grain Zn and Fe concentrations. The elimination of OsNRAMP5 Cd-uptake transporter and the enhancement of root cell vacuolar Cd sequestration reduce uptake and root-to-shoot transport, respectively, resulting in a reduction of grain Cd accumulation.

Healing of Horizontal Intra-alveolar Root Fractures after Endodontic Treatment with Mineral Trioxide Aggregate.

PubMed

Kim, Dohyun; Yue, Wonyoung; Yoon, Tai-Cheol; Park, Sung-Ho; Kim, Euiseong

2016-02-01

The purpose of this retrospective study was to evaluate the healing type and assess the outcome of horizontal intra-alveolar root fractures after endodontic treatment with mineral trioxide aggregate (MTA) as filling material. The clinical database of the Department of Conservative Dentistry at Yonsei University Dental Hospital, Seoul, Korea, was searched for patients with histories of intra-alveolar root fractures and endodontic treatments with MTA between October 2005 and September 2014. Radiographic healing at the fracture line was evaluated independently by 2 examiners and was classified into 4 types according to Andreasen and Hjørting-Hansen. Of the 22 root-fractured teeth that received endodontic treatment with MTA, 19 cases participated in the follow-up after a period of at least 3 months. Seventeen of the 19 teeth (89.5%) exhibited healing of the root fractures. For each healing type, 7 teeth (36.8%) showed healing with calcified tissue, 8 teeth (42.1%) showed interposition of connective tissue, 2 teeth (10.5%) showed interposition of connective tissue and bone, and 2 teeth (10.5%) showed interposition of granulation tissue without healing. Within the limitations of this study, intra-alveolar root fractures showed satisfactory healing outcomes after endodontic treatment with MTA. MTA could be considered to be suitable filling material for the endodontic treatment of horizontal intra-alveolar root fractures. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Ecology of eelgrass meadows of the Atlantic Coast: a community profile

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thayer, G.W.; Kenworthy, W.J.; Fonseca, M.S.

1984-07-01

Eelgrass, Zostera marina, dominates the ecologically important but fragile seagrass communities along the east coast of the United States from North Carolina to Nova Scotia. Grasslike leaves and an extensive root and rhizome system enable eelgrass to exist in a shallow aquatic environment subject to waves, tides, and shifting sediments. Eelgrass meadows are highly productive, frequently rivaling agricultural croplands. They provide shelter and a rich variety of primary and secondary food resources, and form a nursery habitat for the life history stages of numerous fishery organisms. The leaves absorb and release nutrients, provide surfaces for attachment, reduce water current velocity,more » turbulence and scour, and promote accumulation of detritus. Rhizomes provide protection for benthic infauna and enhance sediment stability. Roots absorb and release nutrients to interstitial waters. Because of their shallow, subtidal existence, seagrasses are susceptible to perturbations of both the water column and sediments. Eelgrass meadows are impacted by dredging and filling, some commercial fishery harvest techniques, modification of normal temperature and salinity regimes, and addition of chemical wastes. Techniques have been developed to successfully restore eelgrass habitats, but a holistic approach to planning research and environmentally-related decisions is needed to avoid cumulative environmental impacts on these vital nursery areas. 64 figures, 16 tables.« less

The Performance of a Zirconium-based Root Filling Material with Artifact Reduction Properties in the Detection of Artificially Induced Root Fractures Using Cone-beam Computed Tomographic Imaging.

PubMed

Fox, Aaron; Basrani, Bettina; Lam, Ernest W N

2018-05-01

Limited field of view cone-beam computed tomographic (CBCT) imaging has been used to augment clinical testing of vertical root fractures (VRFs); however, the presence of gutta-percha (GP) in the canal space generates substantial imaging artifacts that make fracture detection difficult. The purpose of this study was to evaluate the influence of a zirconium (Zr)-based root filling material with radiologic properties that reduce beam hardening (BH) artifacts using CBCT imaging in the in vitro diagnosis of VRFs. One hundred seventy-six single-rooted mandibular premolar teeth were obtained, and half of these teeth were filled with GP or Zr (CPoint; EndoTechnologies, LLC, Shrewsbury, MA). VRFs were induced in 44 decoronated teeth in each group using an Instron (Norwood, MA) Universal Testing Machine. Each root was then placed in a dry human mandible and imaged with the Carestream 9000 3D CBCT system (Carestream Dental, Atlanta, GA). The images were evaluated by 6 oral maxillofacial radiologists (OMRs) and residents. The sensitivity was greater for detecting VRFs in the Zr group than the GP group (P = .035). However, the specificity was greater for the GP group than the Zr group (P = .028). Receiver operating characteristic area under the curve values were greater for the Zr group than the GP group, but these differences were not statistically significant. The OMRs outperformed the residents in the detection of VRFs in the Zr group with respect to specificity (P = .006) and positive predictive value (P = .012). The reduced BH of the Zr group improved the sensitivity of the detection of artificially induced VRFs. The ability to detect VRFs in the Zr group was further enhanced by clinical experience. Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Prevalence of technical errors and periapical lesions in a sample of endodontically treated teeth: a CBCT analysis.

PubMed

Nascimento, Eduarda Helena Leandro; Gaêta-Araujo, Hugo; Andrade, Maria Fernanda Silva; Freitas, Deborah Queiroz

2018-01-21

The aims of this study are to identify the most frequent technical errors in endodontically treated teeth and to determine which root canals were most often associated with those errors, as well as to relate endodontic technical errors and the presence of coronal restorations with periapical status by means of cone-beam computed tomography images. Six hundred eighteen endodontically treated teeth (1146 root canals) were evaluated for the quality of their endodontic treatment and for the presence of coronal restorations and periapical lesions. Each root canal was classified according to dental groups, and the endodontic technical errors were recorded. Chi-square's test and descriptive analyses were performed. Six hundred eighty root canals (59.3%) had periapical lesions. Maxillary molars and anterior teeth showed higher prevalence of periapical lesions (p < 0.05). Endodontic treatment quality and coronal restoration were associated with periapical status (p < 0.05). Underfilling was the most frequent technical error in all root canals, except for the second mesiobuccal root canal of maxillary molars and the distobuccal root canal of mandibular molars, which were non-filled in 78.4 and 30% of the cases, respectively. There is a high prevalence of apical radiolucencies, which increased in the presence of poor coronal restorations, endodontic technical errors, and when both conditions were concomitant. Underfilling was the most frequent technical error, followed by non-homogeneous and non-filled canals. Evaluation of endodontic treatment quality that considers every single root canal aims on warning dental practitioners of the prevalence of technical errors that could be avoided with careful treatment planning and execution.

In vitro fracture resistance of roots obturated with epoxy resin-based, mineral trioxide aggregate-based, and bioceramic root canal sealers.

PubMed

Topçuoğlu, Hüseyin Sinan; Tuncay, Öznur; Karataş, Ertuğrul; Arslan, Hakan; Yeter, Kübra

2013-12-01

The aim of this study was to evaluate the fracture resistance of teeth filled with 3 different endodontic sealers. Seventy-five single-rooted extracted mandibular premolars were decoronated to a length of 13 mm. The teeth were randomly divided into 5 groups (n = 15 for each group). In group 1, the teeth were left unprepared and unfilled (negative control), and in group 2, the teeth were left unobturated (positive control). The rest of the roots were prepared by using the ProTaper System up to a master apical file size of F3: group 3, bioceramic sealer (Endosequence BC sealer) + gutta-percha; group 4, mineral trioxide aggregate-based sealer (Tech Biosealer Endo) + gutta-percha; and group 5, epoxy resin-based sealer (AH Plus Jet) + gutta-percha. All root specimens were stored for 2 weeks at 100% humidity to allow the complete setting of the sealers. Each specimen was then subjected to fracture testing by using a universal testing machine at a crosshead speed of 1.0 mm/min(-1) until the root fractured. The force required to fracture each specimen was recorded, and the data were analyzed statistically. The fracture values of groups 3 and 5 were significantly higher than those of group 4 (P < .05). There was no significant difference between groups 3 and 5 (P > .05). In contrast to Tech Biosealer Endo, Endosequence BC and AH Plus Jet sealer increased the force to fracture in root-filled single-rooted premolar teeth. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Three-year follow-up results for non-surgical root canal therapy of idiopathic external root resorption on a maxillary canine with MTA: a case report

PubMed Central

Huang, Zheng; Chen, Li-Li; Wang, Cong-Yi; Dai, Lin; Cheng, Bo; Sun, Jun; Sun, Jun

2014-01-01

External root resorption (ERR) is an uncommon and intractable disease. Treatment alternatives are case-dependant and aim for the repair of the resorptive lesion and long-term retention of the tooth. A forty-year-old Asian female was diagnosed with idiopathic ERR on tooth #11 (the left maxillary canine) by CBCT. Non-surgical root canal therapy was completed with the aid of an operating microscope. The apical third of the root canal was filled with warm gutta-percha and the resorption defect was filled with mineral trioxide aggregate (MTA). The periapical radiographs were taken immediately after operation, one-month follow-up, six-month follow-up and three-year follow-up, respectively. Clinically, the canine was asymptomatic, and no evidence of any further resorption was found. The six-month follow-up radiograph showed initial healing of the bony lesion, while the three-year follow-up radiograph manifested almost complete healing. MTA can be a superior material to be successfully used in the non-surgical treatment of ERR. CBCT is very useful for evaluating the true nature and severity of absorption lesions in root resorption. It is the first complete case report from China about non-surgical treatment of severe ERR along with a relatively long term follow-up. PMID:25031758

Fracture resistance of simulated immature tooth roots reinforced with MTA or restorative materials.

PubMed

Karapinar-Kazandag, Meric; Basrani, Bettina; Tom-Kun Yamagishi, Valerie; Azarpazhooh, Amir; Friedman, Shimon

2016-04-01

Immature endodontically treated teeth may require reinforcing to reduce the risk of root fracture. This study assessed the fracture resistance of simulated immature tooth roots reinforced with mineral trioxide aggregate (MTA) or two composite resin (CR) materials. One hundred extracted roots of mature human maxillary incisors were decoronated and sectioned 9 mm further apically from the decoronation line and randomly divided into five groups (n = 20). In Group 1 (negative control), roots received no treatment. In groups 2-5, canals were enlarged to 2.1 mm diameter to simulate immature roots, dressed with calcium hydroxide (Ca(OH)2 ) and incubated for 7 days. After removal of Ca(OH)2 , canals in Group 2 (positive control) were left unfilled. Canals in groups 3, 4 and 5 were filled with MTA, BisFil 2B flowable CR or BisFil II posterior CR, respectively. After further incubation for 30 days, specimens were embedded in acrylic cylinders and horizontally loaded in a universal testing machine at cross head speed of 5 mm min(-1) until fracture occurred. Load (N) at and pattern of fracture were recorded. Load at fracture was significantly lower (t-test, P = 0.003) in Group 2 (630 ± 199.12) than in Group 1 (896.98 ± 311.79). It did not differ significantly among groups 1, 3, 4 and 5 (anova, P > 0.07). Pattern of fracture did not differ among the groups either. Within the limitations of this study, root canal filling with MTA and two CR materials affected reinforcement of simulated immature roots to levels comparable with intact roots. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of Different Endodontic Sealers on the Push-out Bond Strength of Fiber Posts

PubMed Central

Forough Reyhani, Mohammad; Ghasemi, Negin; Rahimi, Saeed; Milani, Amin Salem; Omrani, Elnaz

2016-01-01

Introduction: The aim of this in vitro study was to evaluate the effect of MTA-based sealer (MTA Fillapex), eugenol-based sealer (Dorifill) and an epoxy resin sealer (AH Plus) on the bond strength of fiber posts cemented with a self-etch adhesive. Materials and Methods: The root canals of 72 maxillary incisors were prepared using the step-back technique after removing/cutting off the crowns. The samples were randomly divided to 4 groups (n=18). In group 1 (the controls) gutta-percha was used without sealer. In groups 2, 3 and 4, the canals were filled with gutta-percha using AH Plus, Dorifill and MTA Fillapex sealers, respectively, by cold lateral compaction technique. After post space preparation, the fiber posts were cemented in the root canals using self-etch adhesive. Then 1-mm-thick disks were prepared from the coronal thirds of all the root canals and subjected to a push-out test. Data were analyzed using the one-way ANOVA and post hoc Tukey’s tests. Results: The maximum (4.45±0.09 MPa) and minimum (1.02±0.03 MPa) bond strength values were recorded in the control and Dorifill groups, respectively. The mean push-out bond strength values were similar for MTA Fillapex and AH Plus sealers (P>0.05). However these values were significantly higher than that of the Dorifill sealer (P<0.05). Conclusion: Sealer type affected the bond strength of the fiber posts and MTA Fillapex decreased the dislodgment resistant of the fiber post. PMID:27141220

Significance of moist root canal dentin with the use of methacrylate-based endodontic sealers: an in vitro coronal dye leakage study.

PubMed

Zmener, Osvaldo; Pameijer, Cornelis H; Serrano, Susana Alvarez; Vidueira, Mercedes; Macchi, Ricardo L

2008-01-01

This in vitro study compared the effect of different levels of moisture of root canals, from none to wet, on the coronal seal after filling with resin-coated gutta-percha cones/EndoRez [RGPC/ER (groups 1-4)], Resilon/Epiphany [RE/EP (groups 5-8)], and gutta-percha/Grossman's cement [GP/G (groups 9-12)]. The length of 76 single-rooted extracted human teeth was standardized to approximately 17 mm. After instrumentation with size 10 K-Files, #2 and #3 Gates Glidden burs, and preparation to the working length with K-Type files, the smear layer was removed with 17% ethylenediaminetetraacetic acid followed by flooding with distilled water. On the basis of similarities of canal shape determined by x-rays, roots were assigned to the groups (n = 5 per group) and treated according to one of the following protocols. (I) ETOH: excess distilled water was removed with paper points followed by dehydration with 95% ethanol; (II) PAPER POINTS: the canals were blot-dried with paper points with the last one appearing dry; (III) MOIST: the canals were dried with low vacuum by using a luer adapter for 5 seconds followed by 1 paper point for 1 second; and (IV) WET: the canals remained totally flooded. The roots were then filled with one of the obturation systems outlined above. The teeth were coated with 2 layers of nail varnish and 1 layer of sticky wax, except for the coronal access. In addition, positive and negative controls were added. After immersion in 2% methylene blue dye for 7 days, the samples were embedded in clear orthodontic resin and cross-sectioned at 0.5-mm intervals along the length of the roots. Dye penetration was evaluated by an independent investigator with a stereomicroscope at 40x magnification. The results indicated that dye leakage was affected by the degree of moisture. All materials evaluated showed some evidence of dye penetration, however, root canals filled with resin-coated gutta-percha/EndoRez and Resilon/Epiphany demonstrated significantly less leakage (P < .05) when moist conditions II and III were present.

Push-out bond strength of fiber posts to root dentin using glass ionomer and resin modified glass ionomer cements.

PubMed

Pereira, Jefferson Ricardo; Rosa, Ricardo Abreu da; Só, Marcus Vinícius Reis; Afonso, Daniele; Kuga, Milton Carlos; Honório, Heitor Marques; Valle, Accácio Lins do; Vidotti, Hugo Alberto

2014-01-01

The purpose of this study was to assess the push-out bond strength of glass fiber posts to root dentin after cementation with glass ionomer (GICs) and resinmodified glass ionomer cements (RMGICs). Fifty human maxillary canines were transversally sectioned at 15 mm from the apex. Canals were prepared with a step back technique until the application of a #55 K-file and filled. Post spaces were prepared and specimens were divided into five groups according to the cement used for post cementation: Luting & Lining Cement; Fuji II LC Improved; RelyX Luting; Ketac Cem; and Ionoseal. After cementation of the glass fiber posts, all roots were stored at 100% humidity until testing. For push-out test, 1-mm thick slices were produced. The push-out test was performed in a universal testing machine at a crosshead speed of 0.5 mm/minute and the values (MPa) were analyzed by Kolmogorov-Smirnov and Levene's tests and by two-way ANOVA and Tukey's post hoc test at a significance level of 5%. Fiber posts cemented using Luting & Lining Cement, Fuji II LC Improved, and Ketac Cem presented the highest bond strength to root dentin, followed by RelyX Luting. Ionoseal presented the lowest bond strength values (P>0.05). The post level did not influence the bond strength of fiber posts to root dentin (P=0.148). The major cause of failure was cohesive at the cement for all GICs and RMGICs. Except for Ionoseal, all cements provided satisfactory bond strength values.

Pathogenesis of apical periodontitis and the causes of endodontic failures.

PubMed

Nair, P N R

2004-11-01

Apical periodontitis is a sequel to endodontic infection and manifests itself as the host defense response to microbial challenge emanating from the root canal system. It is viewed as a dynamic encounter between microbial factors and host defenses at the interface between infected radicular pulp and periodontal ligament that results in local inflammation, resorption of hard tissues, destruction of other periapical tissues, and eventual formation of various histopathological categories of apical periodontitis, commonly referred to as periapical lesions. The treatment of apical periodontitis, as a disease of root canal infection, consists of eradicating microbes or substantially reducing the microbial load from the root canal and preventing re-infection by orthograde root filling. The treatment has a remarkably high degree of success. Nevertheless, endodontic treatment can fail. Most failures occur when treatment procedures, mostly of a technical nature, have not reached a satisfactory standard for the control and elimination of infection. Even when the highest standards and the most careful procedures are followed, failures still occur. This is because there are root canal regions that cannot be cleaned and obturated with existing equipments, materials, and techniques, and thus, infection can persist. In very rare cases, there are also factors located within the inflamed periapical tissue that can interfere with post-treatment healing of the lesion. The data on the biological causes of endodontic failures are recent and scattered in various journals. This communication is meant to provide a comprehensive overview of the etio-pathogenesis of apical periodontitis and the causes of failed endodontic treatments that can be visualized in radiographs as asymptomatic post-treatment periapical radiolucencies.

Push-out bond strength of fiber posts to root dentin using glass ionomer and resin modified glass ionomer cements

PubMed Central

PEREIRA, Jefferson Ricardo; da ROSA, Ricardo Abreu; SÓ, Marcus Vinícius Reis; AFONSO, Daniele; KUGA, Milton Carlos; HONÓRIO, Heitor Marques; do VALLE, Accácio Lins; VIDOTTI, Hugo Alberto

2014-01-01

Objective The purpose of this study was to assess the push-out bond strength of glass fiber posts to root dentin after cementation with glass ionomer (GICs) and resin-modified glass ionomer cements (RMGICs). Material and Methods Fifty human maxillary canines were transversally sectioned at 15 mm from the apex. Canals were prepared with a step back technique until the application of a #55 K-file and filled. Post spaces were prepared and specimens were divided into five groups according to the cement used for post cementation: Luting & Lining Cement; Fuji II LC Improved; RelyX Luting; Ketac Cem; and Ionoseal. After cementation of the glass fiber posts, all roots were stored at 100% humidity until testing. For push-out test, 1-mm thick slices were produced. The push-out test was performed in a universal testing machine at a crosshead speed of 0.5 mm/minute and the values (MPa) were analyzed by Kolmogorov-Smirnov and Levene's tests and by two-way ANOVA and Tukey's post hoc test at a significance level of 5%. Results Fiber posts cemented using Luting & Lining Cement, Fuji II LC Improved, and Ketac Cem presented the highest bond strength to root dentin, followed by RelyX Luting. Ionoseal presented the lowest bond strength values (P>0.05). The post level did not influence the bond strength of fiber posts to root dentin (P=0.148). The major cause of failure was cohesive at the cement for all GICs and RMGICs. Conclusions Except for Ionoseal, all cements provided satisfactory bond strength values. PMID:25004052

Full-mouth treatment of gingival recessions and noncarious cervical lesions with coronally advanced flap and xenogeneic collagen matrix: 
a 2-year case report.

PubMed

Martiniello, Nello; Stefanini, Martina; Zucchelli, Giovanni

In clinical practice it is common to observe adjacent multiple gingival recessions (MGRs) associated with noncarious cervical lesions (NCCLs). The aim of this 2-year case report was to describe the full-mouth treatment of a patient affected by MGRs and NCCLs, with a combined restorative-surgical approach using a coronally advanced flap (CAF) and a xenogeneic collagen matrix (CM). Before surgery, a composite restoration filled the deepest portion of the NCCL defects and was finished at the level of the maximum root coverage (MRC). The surgical technique adopted for the root coverage procedures was CAF for MGRs without vertical releasing incisions in the maxilla, and with one vertical releasing incision in the mandible. The CM was positioned at the level of the cementoenamel junction (CEJ), and sutured at the base of the anatomic de-epithelialized papillae. The flap was shifted coronally, providing complete coverage of the CM, and sutured coronal to the CEJ with a variable number of sling sutures. At 2 years, complete root coverage was achieved in all treated sites, and the patient reported complete resolution of dental hypersensitivity. In the questionnaire, the patient-reported outcome showed a high level of esthetic satisfaction (mean score: 9.6; range: 9 to 10), and the objective esthetic evaluation with the root coverage esthetic score (RES) system showed a very high result (mean: 9.4). The suggested combined restorative-surgical approach provided successful root coverage and a favorable esthetic outcome in the treatment of MGR associated with NCCLs.

Tissue response to silicone rubber when used as a root canal filling.

PubMed

Kasman, F G; Goldman, M

1977-04-01

To test the tissue compatibility of silicone rubber when it is used as a root canal filler, excess material was intentionally forced into the apical tissues in primates. The tissue response was one of general acceptance, with the usual response being fibrotic encapsulation. A low degree of inflammation was noted. Further studies are in progress.

Comparative evaluation of microleakage of various retrograde filling materials: An in vitro study.

PubMed

Galhotra, Virat; Sofat, Anjali; Pandit, Inder K; Gambhir, Ramandeep Singh; Srivastava, Nikhil; Gugnani, Neeraj

2013-07-01

The present study is envisaged to evaluate and compare the microleakage of mineral trioxide aggregate (MTA) with commonly used retrograde filling materials, like light-cured composite with dentin-bonding agents, light-cured glass ionomer cement (LC GIC) and resin-modified zinc oxide eugenol. Ninety freshly extracted non-carious single-rooted human anterior teeth were used in the study. They were randomly divided into four experimental groups and two control groups of 15 each. Following the biomechanical preparation, all teeth were obturated and then the apices of the obturated teeth were resected by removing 3 mm of each apex at 90° to the long axis of the tooth with a straight fissure bur in a high-speed air-rotor handpiece with water coolant. A 3-mm-deep root end cavity was prepared and the root end fillings were placed as per the manufacturer's instructions and according to the groups divided. The samples were then immersed in 1% methylene blue at room temperature for 72 h, 96 h and 1 week and the dye penetration was measured. All the four materials used in the study showed some microleakage throughout the experimental period. The sealing ability in terms of microleakage can be summarized as: MTA > Composite resin with dentin bonding agent > LC GIC > Resin modified zinc oxide eugenol.

Application of lasers in endodontics

NASA Astrophysics Data System (ADS)

Ertl, Thomas P.; Benthin, Hartmut; Majaron, Boris; Mueller, Gerhard J.

1997-12-01

Root canal treatment is still a problem in dentistry. Very often the conventional treatment fails and several treatment sessions are necessary to save the tooth from root resection or extraction. Application of lasers may help in this situation. Bacteria reduction has been demonstrated both in vitro and clinically and is either based on laser induced thermal effects or by using an ultraviolet light source. Root canal cleansing is possible by Er:YAG/YSGG-Lasers, using the hydrodynamic motion of a fluid filled in the canals. However root canal shaping using lasers is still a problem. Via falsas and fiber breakage are points of research.

Comparison of the ultrastructure of conventionally fixed and high pressure frozen/freeze substituted root tips of Nicotiana and Arabidopsis

NASA Technical Reports Server (NTRS)

Kiss, J. Z.; Giddings, T. H. Jr; Staehelin, L. A.; Sack, F. D.

1990-01-01

To circumvent the limitations of chemical fixation (CF) and to gain more reliable structural information about higher plant tissues, we have cryofixed root tips of Nicotiana and Arabidopsis by high pressure freezing (HPF). Whereas other freezing techniques preserve tissue to a relatively shallow depth, HPF in conjunction with freeze substitution (FS) resulted in excellent preservation of entire root tips. Compared to CF, in tissue prepared by HPF/FS: (1) the plasmalemma and all internal membranes were much smoother and often coated on the cytoplasmic side by a thin layer of stained material, (2) the plasmalemma was appressed to the cell wall, (3) organelle profiles were rounder, (4) the cytoplasmic, mitochondrial, and amyloplast matrices were denser, (5) vacuoles contained electron dense material, (6) microtubules appeared to be more numerous and straighter, with crossbridges observed between them, (7) cisternae of endoplasmic reticulum (ER) were wider and filled with material, (8) Golgi intercisternal elements were more clearly resolved and were observed between both Golgi vesicles and cisternae, and (9) larger vesicles were associated with Golgi stacks. This study demonstrates that HPF/FS can be used to successfully preserve the ultrastructure of relatively large plant tissues without the use of intracellular cryoprotectants.

Solubility of a new calcium silicate-based root-end filling material

PubMed Central

Singh, Shishir; Podar, Rajesh; Dadu, Shifali; Kulkarni, Gaurav; Purba, Rucheet

2015-01-01

Introduction: The purpose of this study was to compare solubility of a new calcium silicate-based cement, Biodentine with three commonly used root-end filling materials viz. glass-ionomer cement (GIC), intermediate restorative material (IRM), and mineral trioxide aggregate (MTA). Materials and Methods: Twenty stainless steel ring molds were filled with cements corresponding to four groups (n = 5). The weight of 20 dried glass bottles was recorded. Samples were transferred to bottles containing 5 ml of distilled water and stored for 24 h. The bottles were dried at 105΀C and weighed. This procedure was repeated for 3, 10, 30, and 60 days. Data was analyzed with one-way analysis of variance (ANOVA) test (P < 0.05). Results: Biodentine demonstrated significantly higher solubility than MTA for 30- and 60-day immersion periods. Statistical difference was noted between the solubility values of Biodentine samples amongst each of the five time intervals. Conclusions: Biodentine exhibited higher solubility in comparison with all other cements. PMID:25829696

Copper ion as a new leakage tracer.

PubMed

Modaresi, J; Baharizade, M; Shareghi, A; Ahmadi, M; Daneshkazemi, A

2013-12-01

Most failures of root canal treatments are caused by bacteria. Studies showed that the most common cause of endodontic failures were the incomplete obturation of the root canal and the lack of adequate apical seal. Some in-vitro methods are used to estimate sealing quality, generally by measuring microleakage that allows the tracer agent to penetrate the filled canal. Conventional methods of evaluating the seal of endodontically treated teeth are complicated and have some drawbacks. We used copper ion diffusion method to assess the leakage and the results were compared to dye penetration method. The crowns of 21 extracted teeth were cut off at the CEJ level. After preparing the canals, the teeth were placed in tubes containing saline. They were divided randomly into 15 experimental cases; 3 positive and 3 negative controls. Positive controls were filled by single cone without sealer while the experimental and the negative control groups were filled by lateral technique. The coronal portion of gutta was removed and 9mm was left. The external surface of each tooth was coated with nail polish. Two millimeters of apical portion was immersed into 9ml of distilled water and 0.3ml of CuSO4 solution was injected into the coronal portion. After 2 days, copper sulfate was measured by an atomic absorption spectrophotometer. The teeth were then immersed in 2% methylene blue for 24 hours, sectioned and the extent of dye penetration was measured by a stereomicroscope. The maximum and minimum recorded copper ion concentrations for the experimental group were 18.37 and 2.87ppm respectively. The maximum and minimum recorded dye penetrations for the experimental group were 8.5 and 3.5mm respectively. The statistical analysis, adopting paired samples test, showed poor correlation between average recorded results of two methods. Based on our results, there was no significant correlation between the dye penetration and the copper ion diffusion methods.

Comparative Analysis of Calcium Silicate-based Root Filling Materials Using an Open Apex Model.

PubMed

Tran, Dennis; He, Jianing; Glickman, Gerald N; Woodmansey, Karl F

2016-04-01

Many new calcium silicate-based root filling materials have emerged in the market; however, their performance in the orthograde obturation of an open apex has not been evaluated. The purpose of this study was to compare the marginal adaptation of ProRoot MTA (Dentsply Tulsa Dental, Tulsa, OK), NeoMTA Plus (Avalon Biomed Inc, Bradenton, FL), and Endosequence BC RRM-Fast Set Putty (BC RRM-FS; Brasseler USA, Savannah, GA) after orthograde placement in roots with open apices. Palatal roots of maxillary molars were instrumented to create divergent open apices and divided into 4 groups for orthograde obturation: ProRoot MTA, NeoMTA Plus, BC RRM-FS, and BC RRM-FS + BC Sealer. Using a scanning electron microscope, the quality of material adaptation at the anatomic apex was evaluated by 5 blinded examiners; 3 mm of the root end was sectioned, and gap distance was measured at the material-dentin interface. Statistical analyses were performed using the Kruskal-Wallis test. There were no significant differences in marginal adaptation among the 4 groups at the level of the anatomic apex (P = .175). BC RRM-FS + BC Sealer had a significantly smaller gap size after 3-mm root end resection compared with the other 3 groups (P < .01). No differences were observed among the other 3 materials. All materials showed comparable marginal adaptation at the anatomic apex when used for orthograde obturation of open apices. Application of BC Sealer before the delivery of BC RRM-FS Putty enhanced the quality of adaptation coronal to the apex. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Radiation mechanism for the aerodynamic sound of gears - An explanation for the radiation process by air flow observation

NASA Astrophysics Data System (ADS)

Houjoh, Haruo

1992-12-01

One specific feature of the aerodynamic sound produced at the face end region is that the radiation becomes equally weak by filling root spaces as by shortening the center distance. However, one can easily expect that such actions make the air flow faster, and consequently make the sound louder. This paper attempts to reveal the reason for such a feature. First, air flow induced by the pumping action of the gear pair was analyzed regarding a series of root spaces as volume varying cavities which have channels to adjacent cavities as well as the exit/inlet at the face ends. The numerical analysis was verified by the hot wire anemometer measurement. Next, from the obtained flow response, the sound source was estimated to be a combination of symmetrically distributed simple sources. Taking the effect of either the center distance or root filling into consideration, it is shown that the simplified model can explain such a feature rationally.

Histological study of the effect of some irrigating solutions on bacterial endotoxin in dogs.

PubMed

Silva, Léa Assed Bezerra da; Leonardo, Mario Roberto; Assed, Sada; Tanomaru Filho, Mário

2004-01-01

The aim of this study was to evaluate, histopathologically, the effectiveness of mechanical preparation of root canals using different irrigating solutions in dog teeth filled with LPS after pulpectomy. A total of 120 root canals of 6 mongrel dogs were filled with a solution of LPS after pulpectomy. The irrigating solutions used were saline, 1, 2.5, and 5% sodium hypochlorite, and 2% chlorhexidine. No irrigation was used in the control group. The animals were sacrificed after 60 days and the teeth were fixed and demineralized. Subsequently, serial 6-microm sections were stained with hematoxylin and eosin and Mallory's trichrome for histopathological analysis and Brown-Brenn for verification of bacterial contamination. Analysis showed that the inflammatory infiltrate was statistically less intense in the groups in which the root canals were irrigated with 5% sodium hypochlorite and 2% chlorhexidine. However, none of the irrigating solutions completely inactivated the harmful effects of LPS. Mechanical preparation associated with different irrigating solutions did not completely inactivate LPS.

The Effect of Immediate versus Delayed Dowel Space Preparation on Endodontically Filled Teeth.

DTIC Science & Technology

1981-01-01

solution of 1% sodium hypochlorite (Chlorox Corp., Oakland, CA) to remove any tissue tags attached to the root surface. The crowns of all the teeth were...stored. Two weeks later, twenty more weo~ similarly filled. Using hot endodontic pluggers, dowel spaces were prepare d 4h-th~t eithe 3mm or 71T11 of...Preparation on Endodontically Filled Teeth Acce sion r NTIS .... D TTC TAB Distrilu Av r i 0ou- Dist 1 A! The Effect of Immediate Versus Delayed Dowel

Ecosystem carbon partitioning: aboveground net primary productivity correlates with the root carbon input in different land use types of Southern Alps

NASA Astrophysics Data System (ADS)

Rodeghiero, Mirco; Martinez, Cristina; Gianelle, Damiano; Camin, Federica; Zanotelli, Damiano; Magnani, Federico

2013-04-01

Terrestrial plant carbon partitioning to above- and below-ground compartments can be better understood by integrating studies on biomass allocation and estimates of root carbon input based on the use of stable isotopes. These experiments are essential to model ecosystem's metabolism and predict the effects of global change on carbon cycling. Using in-growth soil cores in conjunction with the 13C natural abundance method we quantified net plant-derived root carbon input into the soil, which has been pointed out as the main unaccounted NPP (net primary productivity) component. Four land use types located in the Trentino Region (northern Italy) and representing a range of aboveground net primary productivity (ANPP) values (155-868 gC m-2 y-1) were investigated: conifer forest, apple orchard, vineyard and grassland. Cores, filled with soil of a known C4 isotopic signature were inserted at 18 sampling points for each site and left in place for twelve months. After extraction, cores were analysed for %C and d13C, which were used to calculate the proportion of new plant-derived root C input by applying a mass balance equation. The GPP (gross primary productivity) of each ecosystem was determined by the eddy covariance technique whereas ANPP was quantified with a repeated inventory approach. We found a strong and significant relationship (R2 = 0.93; p=0.03) between ANPP and the fraction of GPP transferred to the soil as root C input across the investigated sites. This percentage varied between 10 and 25% of GPP with the grassland having the lowest value and the apple orchard the highest. Mechanistic ecosystem carbon balance models could benefit from this general relationship since ANPP is routinely and easily measured at many sites. This result also suggests that by quantifying site-specific ANPP, root carbon input can be reliably estimated, as opposed to using arbitrary root/shoot ratios which may under- or over-estimate C partitioning.

Bond strength to root dentin and fluid filtration test of AH Plus/gutta-percha, EndoREZ and RealSeal systems

PubMed Central

MAHDI, Alaa Abdul; BOLAÑOS-CARMONA, Victoria; GONZALEZ-LOPEZ, Santiago

2013-01-01

Objectives To investigate the bond strength and seal ability produced by AH Plus/gutta-percha, EndoREZ and RealSeal systems to root canal dentin. Material and Methods Sixty extracted single-root human teeth, instrumented manually to size 40, were divided into three groups (n=20) according to the sealer used; G1: AH Plus, G2: EndoREZ, and G3: RealSeal sealers. After filling using the lateral condensation technique, each sealer group was randomly divided into two subgroups according to the tests applied (n=10 for µPush-out test and n=10 for fluid filtration test). A fluid filtration method was used for quantitative evaluation of apical leakage. Four 1-mm-thick slices (cervical and medium level) were obtained from each root sample and a µPush-out test was performed. Failure modes were examined under microscopy at 40x, and a one-way ANOVA was applied to analyze the permeability. Non-parametrical statistics for related (Friedman's and Wilcoxon's rank tests) or unrelated samples (Kruskal-Wallis' and Mann-Whitney's tests) allowed for comparisons of µPush-out strength values among materials at the different levels. Statistical significance was accepted for p values <.05. Results There are no significant differences among fluid filtration of the three sealers. The sealer/core material does not significantly influence the µPush-out bond strength values (F=2.49; p=0.10), although statistically significant differences were detected with regard to root level (Chi2=23.93; p<0.001). AH Plus and RealSeal obtained higher bond strength to intraradicular dentin in the medium root slices. Conclusions There are no significant differences between the permeability and global µPush-out bond strength to root canal dentin achieved by AH Plus/gutta-percha, EndoREZ and RealSeal systems. PMID:24037078

[In vitro evaluation of five root canal sealers].

PubMed

Testarelli, L; Andreasi Bassi, M; Gambarini, G

2003-01-01

An adequate film thickness is an important property of an endodontic sealer, when used in combination with gutta-percha, to eventually fill minimal voids between gutta-percha and the root canal walls, ensuring an hermetic three-dimensional root canal obturation. The goal of the present study was to evaluate the film thickness of the following five root canal sealers: RSA, Rocanal R4, N2, Bioseal and Acroseal. The testing procedures strictly followed ANSI/ADA spec. no. 57 for endodontic filling materials. All root canal sealers were mixed at room temperature strictly following mixing procedures advised by manufacturers. A small amount of sealer was placed between two glass plates and load of 147 N was applied vertically on the top glass plate. After 10 min, the thickness of sealers was measured by a micrometer assembled on a stereomicroscope (Lomo MBC 10). Data were collected and statistically analysed. Results (expressed in micron) were the following: RSA=9,3 (+/-1), Rocanal R4 95 (+/-12), N2 50 (+/-23), Bioseal 41 (+/-13) and Acroseal =9 (+/-2.55). RSA and Acroseal showed the best results (a statistically significant difference was noted among these sealers and the others). On the other hand Bioseal and (partially) N2 showed values compatible with a valid clinical use, while Rocanal R4 showed values higher than minimum standard values allowed by ANSA/ADA spec. no. 57.

Efficacy of CM-Wire, M-Wire, and Nickel-Titanium Instruments for Removing Filling Material from Curved Root Canals: A Micro-Computed Tomography Study.

PubMed

Rodrigues, Clarissa Teles; Duarte, Marco Antonio Hungaro; de Almeida, Marcela Milanezi; de Andrade, Flaviana Bombarda; Bernardineli, Norberti

2016-11-01

The aim of this ex vivo study was to evaluate the removal of filling material after using CM-wire, M-wire, and nickel-titanium instruments in both reciprocating and rotary motions in curved canals. Thirty maxillary lateral incisors were divided into 9 groups according to retreatment procedures: Reciproc R25 followed by Mtwo 40/.04 and ProDesign Logic 50/.01 files; ProDesign R 25/.06 followed by ProDesign Logic 40/.05 and ProDesign Logic 50/.01 files; and Gates-Glidden drills, Hedström files, and K-files up to apical size 30 followed by K-file 40 and K-file 50 up to the working length. Micro-computed tomography scans were performed before and after each reinstrumentation procedure to evaluate root canal filling removal. Statistical analysis was performed with Kruskal-Wallis, Friedman, and Wilcoxon tests (P < .05). No significant differences in filling material removal were found in the 3 groups of teeth. The use of Mtwo and ProDesign Logic 40/.05 rotary files did not enhance filling material removal after the use of reciprocating files. The use of ProDesign Logic 50/.01 files significantly reduced the amount of filling material at the apical levels compared with the use of reciprocating files. Association of reciprocating and rotary files was capable of removing a large amount of filling material in the retreatment of curved canals, irrespective of the type of alloy of the instruments. The use of a ProDesign Logic 50/.01 file for apical preparation significantly reduced the amount of remnant material in the apical portion when compared with reciprocating instruments. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

[Effects of different application rates of water-retaining agent on root physiological characteristics of winter wheat at its different growth stages].

PubMed

Yang, Yong-Hui; Wu, Ji-Cheng; Wu, Pu-Te; Huang, Zhan-Bin; Zhao, Xi-Ning; Guan, Xiu-Juan; He, Fang

2011-01-01

A field experiment was conducted at the Yuzhou Experimental Base of Henan Province to study the effects of different application rates (0, 30, 60, and 90 kg x hm(-2)) of water-retaining agent (WRA) on the root physiological characteristics, biomass, and grain yield of two winter wheat cultivars Zhengmai-9694 and Aikang-58, aimed to probe into the action mechanisms of WRA on the root system of winter wheat at its different growth stages. The application of WRA decreased the root membrane permeability and soluble sugar content, and increased the root vigor. After the application of WRA, the Zhengmai-9694 at its different growth stages had a greater decrement of root membrane permeability, compared with Aikang-58. In all treatments except 90 kg x hm(-2) of WRA, the root vigor of Aikang-58 was obviously higher than that of Zhengmai-9694. At booting and grain-filling stages, the root soluble sugar content of Zhengmai-9694 decreased much more than that of Aikang-58. In the whole growth period of the two cultivars, their root membrane permeability and soluble sugar content were the lowest in treatment 60 kg x hm(-2) of WRA, and no significant differences were observed between treatments 60 and 90 kg x hm(-2) of WRA. The root vigor of Zhengmai-9694 increased remarkably with the increasing rate of WRA application, while that of Aikang-58 was the highest in treatment 60 kg x hm(-2) of WRA. The application of WRA also increased root biomass, and at jointing and booting stages, the root biomass of Aikang-58 was much higher than that of Zhengmai-9694. However, at grain-filling stage, the biomass of Aikang-58 in treatments 60 and 90 kg x hm(-2) of WRA was lower than that of Zhengmai-9694. Treatment 60 kg x hm(-2) of WRA had the highest grain yield of the two cultivars. It was concluded that WRA had more significant effects on Zhengmai-9694 than on Aikang-58, and applying 60 kg x hm(-2) of WRA could obtain the best effect.

Five-year longitudinal assessment of the prognosis of apical microsurgery.

PubMed

von Arx, Thomas; Jensen, Simon S; Hänni, Stefan; Friedman, Shimon

2012-05-01

Apical surgery is an important treatment option for teeth with post-treatment apical periodontitis. Knowledge of the long-term prognosis is necessary when weighing apical surgery against alternative treatments. This study assessed the 5-year outcome of apical surgery and its predictors in a cohort for which the 1-year outcome was previously reported. Apical microsurgery procedures were uniformly performed using SuperEBA (Staident International, Staines, UK) or mineral trioxide aggregate (MTA) (ProRoot MTA; Dentsply Tulsa Dental Specialties, Tulsa, OK) root-end fillings or alternatively Retroplast capping (Retroplast Trading, Rorvig, Denmark). Subjects examined at 1 year (n = 191) were invited for the 5-year clinical and radiographic examination. Based on blinded, independent assessment by 3 calibrated examiners, the dichotomous outcome (healed or nonhealed) was determined and associated with patient-, tooth-, and treatment-related variables using logistic regression. At the 5-year follow-up, 9 of 191 teeth were unavailable, 12 of 191 teeth were extracted, and 170 of 191 teeth were examined (87.6% recall rate). A total of 129 of 170 teeth were healed (75.9%) compared with 83.8% at 1 year, and 85.3% were asymptomatic. Two significant outcome predictors were identified: the mesial-distal bone level at ≤ 3 mm versus >3 mm from the cementoenamel junction (78.2% vs 52.9% healed, respectively; odds ratio = 5.10; confidence interval, 1.67-16.21; P < .02) and root-end fillings with ProRoot MTA versus SuperEBA (86.4% vs. 67.3% healed, respectively; odds ratio = 7.65; confidence interval, 2.60-25.27; P < .004). This study suggested that the 5-year prognosis after apical microsurgery was 8% poorer than assessed at 1 year. It also suggested that the prognosis was significantly impacted by the interproximal bone levels at the treated tooth and by the type of root-end filling material used. Copyright © 2012 American Association of Endodontists. All rights reserved.

Efficacy of two rotary retreatment systems in removing Gutta-percha and sealer during endodontic retreatment with or without solvent: A comparative in vitro study.

PubMed

Bhagavaldas, Moushmi Chalakkarayil; Diwan, Abhinav; Kusumvalli, S; Pasha, Shiraz; Devale, Madhuri; Chava, Deepak Chowdary

2017-01-01

The aim of this in vitro study was to compare the efficacy of two retreatment rotary systems in the removal of Gutta-percha (GP) and sealer from the root canal walls with or without solvent. Forty-eight extracted human mandibular first premolars were prepared and obturated with GP and AH Plus sealer. Samples were then randomly divided into four groups. Group I was retreated with MtwoR rotary system without solvent, Group II was retreated with MtwoR rotary system with Endosolv R as the solvent, Group III with D-RaCe rotary system without solvent, and Group IV with D-RaCe rotary system and Endosolv R solvent. The cleanliness of canal walls was determined by stereomicroscope (×20) and AutoCAD software. Kruskal-Wallis test and Mann-Whitney U-test were used to compare the data. Results showed that none of the retreatment systems used in this study was able to completely remove the root canal filling material. D-RaCe with or without solvent showed significantly ( P > 0.05) less filling material at all levels compared to MtwoR with/without solvent. Within the limitation of the current study, D-RaCe rotary retreatment system is more effective in removing filling material from root canal walls when compared to MtwoR rotary retreatment system.

In vitro fabrication of dental filling nanopowder by green route and its antibacterial activity against dental pathogens.

PubMed

Lee, Jeong-Ho; Velmurugan, Palanivel; Park, Jung-Hee; Lee, Kui-Jae; Jin, Jong-Sik; Park, Yool-Jin; Bang, Keuk-Soo; Oh, Byung-Taek

2016-06-01

The aim of this study was to introduce novel Sn, Cu, Hg, and Ag nanopowders (NPs) and a composite nanopowder (NP) synthesized using Salvia miltiorrhiza Bunge (SM) root extract as a reducing and capping agent to improve the antibacterial property of dental filling materials. All of the NPs obtained were characterized using a scanning transmission electron microscope (STEM), and energy dispersive X-ray (EDX) spectrum imaging was performed to map the elemental distributions of the NP composite. Fourier transform infrared (FTIR) spectroscopy was performed to identify the role of various functional groups in all of the obtained NPs and the phyto-compound responsible for the reduction of various metal ions. The X-ray diffraction (XRD) patterns clearly illustrated the crystalline phase of the synthesized NP. The antibacterial properties of the synthesized Sn, Cu, Hg, Ag, composite NP, SM root extract, and commercial amalgam powder were evaluated. The Cu, composite NP, SM root extract and Ag NP displayed excellent antibacterial activity against dental bacteria Streptococcus mutans and Lactobacillus acidophilus. The results of this study require further evaluation for signs of metal toxicity in appropriate animal models. However, the results are encouraging for the application of metal NPs as suitable alternatives for antibiotics and disinfectants, especially in dental filling materials. Copyright © 2016 Elsevier B.V. All rights reserved.

Physical characteristics, antimicrobial and odontogenesis potentials of calcium silicate cement containing hinokitiol.

PubMed

Huang, Ming-Hsien; Shen, Yu-Fang; Hsu, Tuan-Ti; Huang, Tsui-Hsien; Shie, Ming-You

2016-08-01

Hinokitiol is a natural material and it has antibacterial and anti-inflammatory effects. The purpose of this study was to evaluate the material characterization, cell viability, antibacterial and anti-inflammatory abilities of the hinokitiol-modified calcium silicate (CS) cement as a root end filling material. The setting times, diametral tensile strength (DTS) values and XRD patterns of CS cements with 0-10mM hinokitiol were examined. Then, the antibacterial effect and the expression levels of cyclooxygenase 2 (COX-2) and interleukin-1 (IL-1) of the hinokitiol-modified CS cements were evaluated. Furthermore, the cytocompatibility, the expression levels of the markers of odontoblastic differentiation, mineralized nodule formation and calcium deposition of human dental pulp cells (hDPCs) cultured on hinokitiol-modified CS cements were determined. The hinokitiol-modified CS cements had better antibacterial and anti-inflammatory abilities and cytocompatibility than non-modified CS cements. Otherwise, the hinokitiol-modified CS cements had suitable setting times and better odontoblastic potential of hDPCs. Previous report pointed out that the root-end filling materials may induce inflammatory cytokines reaction. In our study, hinokitiol-modified CS cements not only inhibited the expression level of inflammatory cytokines, but also had better cytocompatibility, antimicrobial properties and active ability of odontoblastic differentiation of hDPCs. Therefore, the hinokitiol-modified CS cement may be a potential root end filling material for clinic. Copyright © 2016 Elsevier B.V. All rights reserved.

[Pain, flare-ups and failures in root canal therapy].

PubMed

Moorer, W R

1989-10-01

In this overview the incidences and causes of pain, flare-ups and failures that occur after root canal therapy are discussed. Infection is considered the most important single, underlying determinant of the many factors that may cause pain and failures. Therefore, strict adherence to recognized therapeutic principles of shaping, disinfection and filling, in addition to proper aftercare, is of importance to diminish postoperative sequelae.

Computed Tomographic Evaluation of K3 Rotary and Stainless Steel K File Instrumentation in Primary Teeth

PubMed Central

Kavitha, Swaminathan; Thomas, Eapen; Anadhan, Vasanthakumari; Vijayakumar, Rajendran

2016-01-01

Introduction The intention of root canal preparation is to reduce infected content and create a root canal shape allowing for a well condensed root filling. Therefore, it is not necessary to remove excessive dentine for successful root canal preparation and concern must be taken not to over instrument as perforations can occur in the thin dentinal walls of primary molars. Aim This study was done to evaluate the time preparation, the risk of lateral perforation and dentine removal of the stainless steel K file and K3 rotary instrumentation in primary teeth. Materials and Methods Seventy-five primary molars were selected and divided into three groups. Using spiral computed tomography the teeth were scanned before instrumentation. Teeth were prepared using a stainless steel K file for manual technique. All the canals were prepared up to file size 35. In K3 rotary files (.02 taper) instrumentation was done up to 35 size file. In K3 rotary files (.04 taper) the instrumentation was done up to 25 size file and simultaneously the instrumentation time was recorded. The instrumented teeth were once again scanned and the images were compared with the images of the uninstrumented canals. Statistical Analysis Data was statistically analysed using Kruskal Wallis One-way ANOVA, Mann-Whitney U-Test and Pearson’s Chi-square Test. Results K3 rotary files (.02 taper) removed a significantly less amount of dentine, required less instrumentation time than a stainless steel K file. Conclusion K3 files (.02 taper) generated less dentine removal than the stainless steel K file and K3 files (.04 taper). K3 rotary files (.02 taper) were more effective for root canal instrumentation in primary teeth. PMID:26894166

[Sealing properties of three resin-based sealers].

PubMed

Mai, Sui; Wu, Shiyu; Gu, Lisha; Qi, Yipin; Sun, Qiurong; Ling, Junqi

2014-11-01

To evaluate the sealing properties of three resin- based sealers, EndoREZ, RealSEAL and RealSEAL SE. Forthy-eight extracted human anterior teeth with single root and canal were prepared using ProTaper files with crown-down technique to F3. The teeth were filled with three sealer respectively with hot gutta- percha vertical condensation technique simulating the clinical situation. Leakage quantity was detected using computerized fluid filtration meter with 10 samples in each group. The cross section morphology of apical parts of roots of 5 mm was observed with scanning electron microscope and transmission electron microscope in 3 samples of each group, respectively. The leakage quantity of EndoREZ, RealSEAL and RealSEAL SE were (2.61±0.60), (1.43±0.11) and (1.76±0.18) µl/min, respectively. The gaps between the the sealer and the canal wall were increased in in order of RealSEAL, RealSEAL SE and EndoREZ. No obvious demineralized dentin under EndoREZ and the smear layer was not completed removed. The partly demineralized dentin was observed under RealSEAL and the smear layer was totally removed. The partly demineralized dentin was seen under RealSEAL SE and the majority of smear layer was removed. Among the three resin- based sealers, RealSEAL has the best sealing properties, followed by RealSEAL SE and EndoREZ.

Molecular Mechanisms of Root Gravitropism.

PubMed

Su, Shih-Heng; Gibbs, Nicole M; Jancewicz, Amy L; Masson, Patrick H

2017-09-11

Plant shoots typically grow against the gravity vector to access light, whereas roots grow downward into the soil to take up water and nutrients. These gravitropic responses can be altered by developmental and environmental cues. In this review, we discuss the molecular mechanisms that govern the gravitropism of angiosperm roots, where a physical separation between sites for gravity sensing and curvature response has facilitated discovery. Gravity sensing takes place in the columella cells of the root cap, where sedimentation of starch-filled plastids (amyloplasts) triggers a pathway that results in a relocalization to the lower side of the cell of PIN proteins, which facilitate efflux of the plant hormone auxin efflux. Consequently, auxin accumulates in the lower half of the root, triggering bending of the root tip at the elongation zone. We review our understanding of the molecular mechanisms that control this process in primary roots, and discuss recent insights into the regulation of oblique growth in lateral roots and its impact on root-system architecture and soil exploration. Copyright © 2017 Elsevier Ltd. All rights reserved.

Speckle tracking and speckle content based composite strain imaging for solid and fluid filled lesions.

PubMed

Rabbi, Md Shifat-E; Hasan, Md Kamrul

2017-02-01

Strain imaging though for solid lesions provides an effective way for determining their pathologic condition by displaying the tissue stiffness contrast, for fluid filled lesions such an imaging is yet an open problem. In this paper, we propose a novel speckle content based strain imaging technique for visualization and classification of fluid filled lesions in elastography after automatic identification of the presence of fluid filled lesions. Speckle content based strain, defined as a function of speckle density based on the relationship between strain and speckle density, gives an indirect strain value for fluid filled lesions. To measure the speckle density of the fluid filled lesions, two new criteria based on oscillation count of the windowed radio frequency signal and local variance of the normalized B-mode image are used. An improved speckle tracking technique is also proposed for strain imaging of the solid lesions and background. A wavelet-based integration technique is then proposed for combining the strain images from these two techniques for visualizing both the solid and fluid filled lesions from a common framework. The final output of our algorithm is a high quality composite strain image which can effectively visualize both solid and fluid filled breast lesions in addition to the speckle content of the fluid filled lesions for their discrimination. The performance of our algorithm is evaluated using the in vivo patient data and compared with recently reported techniques. The results show that both the solid and fluid filled lesions can be better visualized using our technique and the fluid filled lesions can be classified with good accuracy. Copyright © 2016 Elsevier B.V. All rights reserved.

Hot-wire Laser Welding of Deep and Wide Gaps

NASA Astrophysics Data System (ADS)

Näsström, J.; Frostevarg, J.; Silver, T.

Heavy section Gas Metal Arc Welding (GMAW) usually requires special edge preparation and several passes. One alternative for increased performance is Laser Arc Hybrid Welding (LAHW). For very thick sheets however, imperfections like root drops or solidification cracks can occur. In this study, other techniques are also studied, including multi-pass filling of deep gaps with wire deposition. A laser is then used to melt the filler and base material. The hot- and cold wire laser welding processes are highly sensitive to wire-laser positioning, where controlled melting of the wire is essential. Apart from a comprehensive literature survey, preliminary experiments were also performed in order to find a novel method variant that can successfully fill deep and wide gaps. The method applied uses a defocused laser that generates the melt pool. A resistance heated wire is fed into the melt pool front in a leading position. This is similar to additive manufacturing techniques such as laser direct metal deposition with wire. A layer height of several millimeters can be achieved and rather low laser power can be chosen. The preliminary experiments were observed using high speed imaging and briefly evaluated by visual examination of the resulting beads. Using a defocused laser beam turned out to have two major advantages; 1. It adds heat to the melt pool in a manner that properly fuses the bottom and walls of the base material. 2. It counteracts difficulties due to an irregularly oscillating filler wire. These early results show that this can be a promising technique for joining thick steels with wide gaps.

Large-scale tomographic particle image velocimetry using helium-filled soap bubbles

NASA Astrophysics Data System (ADS)

Kühn, Matthias; Ehrenfried, Klaus; Bosbach, Johannes; Wagner, Claus

2011-04-01

To measure large-scale flow structures in air, a tomographic particle image velocimetry (tomographic PIV) system for measurement volumes of the order of one cubic metre is developed, which employs helium-filled soap bubbles (HFSBs) as tracer particles. The technique has several specific characteristics compared to most conventional tomographic PIV systems, which are usually applied to small measurement volumes. One of them is spot lights on the HFSB tracers, which slightly change their position, when the direction of observation is altered. Further issues are the large particle to voxel ratio and the short focal length of the used camera lenses, which result in a noticeable variation of the magnification factor in volume depth direction. Taking the specific characteristics of the HFSBs into account, the feasibility of our large-scale tomographic PIV system is demonstrated by showing that the calibration errors can be reduced down to 0.1 pixels as required. Further, an accurate and fast implementation of the multiplicative algebraic reconstruction technique, which calculates the weighting coefficients when needed instead of storing them, is discussed. The tomographic PIV system is applied to measure forced convection in a convection cell at a Reynolds number of 530 based on the inlet channel height and the mean inlet velocity. The size of the measurement volume and the interrogation volumes amount to 750 mm × 450 mm × 165 mm and 48 mm × 48 mm × 24 mm, respectively. Validation of the tomographic PIV technique employing HFSBs is further provided by comparing profiles of the mean velocity and of the root mean square velocity fluctuations to respective planar PIV data.

Permeation fill-tube design for inertial confinement fusion target capsules

DOE PAGES

Rice, B. S.; Ulreich, J.; Fella, C.; ...

2017-03-22

A unique approach for permeation filling of nonpermeable inertial confinement fusion target capsules with deuterium–tritium (DT) is presented. This process uses a permeable capsule coupled into the final target capsule with a 0.03-mm-diameter fill tube. Leak free permeation filling of glow-discharge polymerization (GDP) targets using this method have been successfully demonstrated, as well as ice layering of the target, yielding an inner ice surface roughness of 1-more » $$\\unicode[STIX]{x03BC}$$m rms (root mean square). Finally, the measured DT ice-thickness profile for this experiment was used to validate a thermal model’s prediction of the same thickness profile.« less

Root architecture simulation improves the inference from seedling root phenotyping towards mature root systems

PubMed Central

Zhao, Jiangsan; Rewald, Boris; Leitner, Daniel; Nagel, Kerstin A.; Nakhforoosh, Alireza

2017-01-01

Abstract Root phenotyping provides trait information for plant breeding. A shortcoming of high-throughput root phenotyping is the limitation to seedling plants and failure to make inferences on mature root systems. We suggest root system architecture (RSA) models to predict mature root traits and overcome the inference problem. Sixteen pea genotypes were phenotyped in (i) seedling (Petri dishes) and (ii) mature (sand-filled columns) root phenotyping platforms. The RSA model RootBox was parameterized with seedling traits to simulate the fully developed root systems. Measured and modelled root length, first-order lateral number, and root distribution were compared to determine key traits for model-based prediction. No direct relationship in root traits (tap, lateral length, interbranch distance) was evident between phenotyping systems. RootBox significantly improved the inference over phenotyping platforms. Seedling plant tap and lateral root elongation rates and interbranch distance were sufficient model parameters to predict genotype ranking in total root length with an RSpearman of 0.83. Parameterization including uneven lateral spacing via a scaling function substantially improved the prediction of architectures underlying the differently sized root systems. We conclude that RSA models can solve the inference problem of seedling root phenotyping. RSA models should be included in the phenotyping pipeline to provide reliable information on mature root systems to breeding research. PMID:28168270

Can Degradation of Adhesive Interfaces Due to Water Storage Affect Stress Distributions? A Finite-Element Stress Analysis Study.

PubMed

Belli, Sema; Eraslan, Oğuz; Eskitaşcıoğlu, Gürcan

The aim of this finite-element stress analysis (FEA) was to determine the effect of degradation due to water storage on stress distributions in root-filled premolar models restored with composite using either a self-etch (SE) or an etch-and-rinse (E&R) adhesive. Four premolar FEA models including root filling, MOD cavity, and composite restorations were created. The cavities were assumed to be treated by SE or E&R adhesives and stored in water for 18 months. The elastic properties of the adhesive-dentin interface after 24-h and 18-month water storage were obtained from the literature and applied to the FEA models. A 300-N load was applied on the functional cusps of the models. The SolidWorks/Cosmosworks structural analysis program was used and the results were presented considering the von Mises stresses. Stresses in the cervical region increased over time on the load-application side of the main tooth models (SE: 84.11 MPa to 87.51 MPa; E&R: 100.24 MPa to 120.8 MPa). When the adhesive interfaces (hybrid layer, adhesive layer) and dentin were evaluated separately, the stresses near the root canal orifices increased over time in both models; however, this change was more noticeable in the E&R models. Stresses at the cavity corners decreased in the E&R model (within the adhesive layer), while SE models showed the opposite (within the hybrid layer). Change in the elastic modulus of the adhesive layer, hybrid layer, and dentin due to water storage has an effect on stresses in root-filled premolar models. The location and the level of the stresses differed depending on the adhesive used.

The failures of root canal preparation with hand ProTaper.

PubMed

Bătăiosu, Marilena; Diaconu, Oana; Moraru, Iren; Dăguci, C; Tuculină, Mihaela; Dăguci, Luminiţa; Gheorghiţă, Lelia

2012-07-01

The failures of root canal preparation are due to some anatomical deviation (canal in "C" or "S") and some technique errors. The technique errors are usually present in canal root cleansing and shaping stage and are the result of endodontic treatment objectives deviation. Our study was made on technique errors while preparing the canal roots with hand ProTaper. Our study was made "in vitro" on 84 extracted teeth (molars, premolars, incisors and canines). The canal root of these teeth were cleansed and shaped with hand ProTaper by crown-down technique and canal irrigation with NaOCl(2,5%). The dental preparation control was made by X-ray. During canal root preparation some failures were observed like: canal root overinstrumentation, zipping and stripping phenomenon, discarded and/or fractured instruments. Hand ProTaper represents a revolutionary progress of endodontic treatment, but a deviation from accepted rules of canal root instrumentation can lead to failures of endodontic treatment.

Traits and selection strategies to improve root systems and water uptake in water-limited wheat crops.

PubMed

Wasson, A P; Richards, R A; Chatrath, R; Misra, S C; Prasad, S V Sai; Rebetzke, G J; Kirkegaard, J A; Christopher, J; Watt, M

2012-05-01

Wheat yields globally will depend increasingly on good management to conserve rainfall and new varieties that use water efficiently for grain production. Here we propose an approach for developing new varieties to make better use of deep stored water. We focus on water-limited wheat production in the summer-dominant rainfall regions of India and Australia, but the approach is generally applicable to other environments and root-based constraints. Use of stored deep water is valuable because it is more predictable than variable in-season rainfall and can be measured prior to sowing. Further, this moisture is converted into grain with twice the efficiently of in-season rainfall since it is taken up later in crop growth during the grain-filling period when the roots reach deeper layers. We propose that wheat varieties with a deeper root system, a redistribution of branch root density from the surface to depth, and with greater radial hydraulic conductivity at depth would have higher yields in rainfed systems where crops rely on deep water for grain fill. Developing selection systems for mature root system traits is challenging as there are limited high-throughput phenotyping methods for roots in the field, and there is a risk that traits selected in the lab on young plants will not translate into mature root system traits in the field. We give an example of a breeding programme that combines laboratory and field phenotyping with proof of concept evaluation of the trait at the beginning of the selection programme. This would greatly enhance confidence in a high-throughput laboratory or field screen, and avoid investment in screens without yield value. This approach requires careful selection of field sites and years that allow expression of deep roots and increased yield. It also requires careful selection and crossing of germplasm to allow comparison of root expression among genotypes that are similar for other traits, especially flowering time and disease and toxicity resistances. Such a programme with field and laboratory evaluation at the outset will speed up delivery of varieties with improved root systems for higher yield.

Analysis of the cause of failure in nonsurgical endodontic treatment by microscopic inspection during endodontic microsurgery.

PubMed

Song, Minju; Kim, Hyeon-Cheol; Lee, Woocheol; Kim, Euiseong

2011-11-01

This study examined the clinical causes of failure and the limitation of a previous endodontic treatment by an inspection of the root apex and resected root surface at 26× magnification during endodontic microsurgery. The data were collected from patients in the Department of Conservative Dentistry at the Dental College, Yonsei University in Seoul, Korea between March 2001 and January 2011. All root-filled cases with symptomatic or asymptomatic apical periodontitis were enrolled in this study. All surgical procedures were performed by using an operating microscope. The surface of the apical root to be resected or the resected root surface after methylene blue staining was examined during the surgical procedure and recorded carefully with 26× magnification to determine the state of the previous endodontic treatment by using an operating microscope. Among the 557 cases with periapical surgery, 493 teeth were included in this study. With the exclusion of unknown cases, the most common possible cause of failure was perceived leakage around the canal filling material (30.4%), followed by a missing canal (19.7%), underfilling (14.2%), anatomical complexity (8.7%), overfilling (3.0%), iatrogenic problems (2.8%), apical calculus (1.8%), and cracks (1.2%). The frequency of possible failure causes differed according to the tooth position (P < .001). An appreciation of the root canal anatomy by using an operating microscope in nonsurgical endodontic treatment can make the prognosis more predictable and favorable. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Comparison of efficacy of pulverization and sterile paper point techniques for sampling root canals.

PubMed

Tran, Kenny T; Torabinejad, Mahmoud; Shabahang, Shahrokh; Retamozo, Bonnie; Aprecio, Raydolfo M; Chen, Jung-Wei

2013-08-01

The purpose of this study was to compare the efficacy of the pulverization and sterile paper point techniques for sampling root canals using 5.25% NaOCl/17% EDTA and 1.3% NaOCl/MTAD (Dentsply, Tulsa, OK) as irrigation regimens. Single-canal extracted human teeth were decoronated and infected with Enterococcus faecalis. Roots were randomly assigned to 2 irrigation regimens: group A with 5.25% NaOCl/17% EDTA (n = 30) and group B with 1.3% NaOCl/MTAD (n = 30). After chemomechanical debridement, bacterial samplings were taken using sterile paper points and pulverized powder of the apical 5 mm root ends. The sterile paper point technique did not show growth in any samples. The pulverization technique showed growth in 24 of the 60 samples. The Fisher exact test showed significant differences between sampling techniques (P < .001). The sterile paper point technique showed no difference between irrigation regimens. However, 17 of the 30 roots in group A and 7 of the 30 roots in group B resulted in growth as detected by pulverization technique. Data showed a significant difference between irrigation regimens (P = .03) in pulverization technique. The pulverization technique was more efficacious in detecting viable bacteria. Furthermore, this technique showed that 1.3% NaOCl/MTAD regimen was more effective in disinfecting root canals. Published by Elsevier Inc.

An atraumatic restorative treatment (ART) technique: evaluation after one year.

PubMed

Frencken, J E; Songpaisan, Y; Phantumvanit, P; Pilot, T

1994-10-01

Extraction is the most common dental treatment provided for people in rural and suburban areas in many less-industrialised countries. By comparison, restorative care is rarely provided. In order to improve such situations, a treatment technique has been developed based only on hand excavation of carious lesions and using glass-ionomer cement as a filling material and a sealant. This Atraumatic Restorative Treatment (ART) technique follows the concept of minimal intervention and does not require electrically driven equipment. This paper reports on the longevity of fillings and sealants placed using the technique under field conditions in rural Thailand. Dental caries was treated using the ART technique in one village, whilst the population in a second village received restorative care (amalgam fillings) through mobile dental units. A third village was the control. After one year, 79 per cent of single surface ART fillings and 55 per cent of ART fillings of greater than one surface placed in deciduous teeth were judged successful. The success rate of ART fillings in the permanent dentition (mainly single surface fillings) was 93 per cent and the retention rate for sealants was 78 per cent. Children were pleased at having received treatment by this technique and showed little fear. The ART technique is a promising caries treatment procedure for use in rural and sub-urban areas in less-industrialised countries.

Valve sparing aortic replacement - root remodeling.

PubMed

Lausberg, Henning F; Schäfers, Hans-Joachim

2006-01-01

Aortic root remodeling restores aortic root geometry and improves valve competence. We have used this technique whenever aorto-ventricular diameter is preserved. The operative technique is detained in this presentation. As a result of our 10-year experience with root remodeling we propose this operation as a reproducible option for patients with dilatation of the aortic root.

Sealing ability of mineral trioxide aggregate (MTA) combined with distilled water, chlorhexidine, and doxycycline.

PubMed

Arruda, Roberta A A; Cunha, Rodrigo S; Miguita, Kenner B; Silveira, Cláudia F M; De Martin, Alexandre S; Pinheiro, Sérgio L; Rocha, Daniel G P; Bueno, Carlos E S

2012-09-01

The aim of this study was to evaluate the sealing ability of mineral trioxide aggregate (MTA Bio) combined with different mixing agents (distilled water, chlorhexidine, doxycycline), used as an apical root-end filling material. Forty-two extracted human teeth were divided into three groups (n = 12); six teeth were used as controls. Root-ends were resected at 90 degrees, 3 mm from the apex. Root-end cavities were prepared using ultrasonic tips and filled with MTA Bio plus distilled water, 2% chlorhexidine solution, or 10% doxycycline solution. Apical sealing was assessed by microleakage of 50% silver nitrate solution. Roots were longitudinally sectioned in a buccolingual plane and analyzed using an operating microscope (20× magnification). Depth of dye leakage into the dentinal walls was measured in millimeters. Results were analyzed using ANOVA and Tukey's test (P = 0.05). MTA Bio plus distilled water showed significantly higher mean leakage results (1.06 mm) when compared with MTA Bio plus doxycycline (0.61 mm), and higher, although not significant, results when compared with MTA Bio plus chlorhexidine (0.79 mm). In conclusion, replacing distilled water with two biologically active mixing agents (doxycycline and chlorhexidine) did not alter the sealing properties of MTABio. The antimicrobial properties of these combinations should be further investigated.

The Effect of File Size and Type and Irrigation Solutions on the Accuracy of Electronic Apex Locators: An In Vitro Study on Canine Teeth.

PubMed

Janeczek, Maciej; Kosior, Piotr; Piesiak-Pańczyszyn, Dagmara; Dudek, Krzysztof; Chrószcz, Aleksander; Czajczyńska-Waszkiewicz, Agnieszka; Kowalczyk-Zając, Małgorzata; Gabren-Syller, Aleksandra; Kirstein, Karol; Skalec, Aleksandra; Bryła, Ewelina; Dobrzyński, Maciej

2016-01-01

Measurements of the root canal during endodontic treatment have a significant influence on the course of the therapeutic process as well as on its final result in both human and veterinary medicine. The apical constriction should be the termination point for the preparation and filling of the root canal. This research was conducted with the use of a Septodont kit consisting of a small chamber filled with the examined solution in which a healthy second incisor was placed. The step back method was applied for the root canal preparation and master apical file of 30 was used. The working length was 22 mm. The examination was conducted with the use of steel as well as nickel titanium hand instruments. Different irrigation solutions and two types of apex locators were used. Measurements of the working length of the root canal showed dependence on the size of the instrument. Examinations carried out in various environments showed that analogical measurements were obtained only for sodium hypochlorite solutions. In other environments the measured sections were shortened. Comparative examinations with the use of steel instruments demonstrated insignificant measurement differences. Compared to these results, the measurements in nickel titanium group were characterized by more considerable deviations.

The Effect of File Size and Type and Irrigation Solutions on the Accuracy of Electronic Apex Locators: An In Vitro Study on Canine Teeth

PubMed Central

Kosior, Piotr; Piesiak-Pańczyszyn, Dagmara; Dudek, Krzysztof; Chrószcz, Aleksander; Czajczyńska-Waszkiewicz, Agnieszka; Kowalczyk-Zając, Małgorzata; Gabren-Syller, Aleksandra; Bryła, Ewelina

2016-01-01

Measurements of the root canal during endodontic treatment have a significant influence on the course of the therapeutic process as well as on its final result in both human and veterinary medicine. The apical constriction should be the termination point for the preparation and filling of the root canal. This research was conducted with the use of a Septodont kit consisting of a small chamber filled with the examined solution in which a healthy second incisor was placed. The step back method was applied for the root canal preparation and master apical file of 30 was used. The working length was 22 mm. The examination was conducted with the use of steel as well as nickel titanium hand instruments. Different irrigation solutions and two types of apex locators were used. Measurements of the working length of the root canal showed dependence on the size of the instrument. Examinations carried out in various environments showed that analogical measurements were obtained only for sodium hypochlorite solutions. In other environments the measured sections were shortened. Comparative examinations with the use of steel instruments demonstrated insignificant measurement differences. Compared to these results, the measurements in nickel titanium group were characterized by more considerable deviations. PMID:27747242

A comparison of the sealing ability of various temporary restorative materials to seal the access cavity: An in vitro study.

PubMed

Markose, Aji; Krishnan, Ramesh; Ramesh, Maya; Singh, Shishir

2016-10-01

In multiple-appointment root canal treatment, a temporary filling material is used to seal the access cavity between visits. The primary function of this material is to prevent the contamination of the root canal system by fluids, organic debris, and bacteria from the oral cavity. A total of fifty extracted noncarious unrestored human maxillaryanterior teeth with intact crowns and roots were selected The canals were instrumented using stepback technique and sodium hypochlorite (3%) and hydrogen peroxide (3%) were used as irrigants for each specimen alternatively. The coronal two-thirds of each canal were flared using Gates-Glidden drills up to no. 3 size and obturated with Gutta-percha using zinc oxide-eugenol (ZnOE) as sealer. The teeth were then randomly selected and divided into six groups out of which four were experimental groups and two control groups. The teeth were then immersed in 2% methylene blue dye solution for 3 days. All sealing materials and Gutta-percha were gently removed from the walls of the canal, and the entire circumference of the canal wall examined for dye penetration. The lowest mean leakage was in the Fermit-N group followed by Cavit-W, ZnOE, intermediate restorative materials (IRM), and positive control. Fermit-N showed better sealing ability compared to cavit, ZnOE and IRM.

Endodontic treatment of a mandibular second premolar with three root canals.

PubMed

Aguiar, Carlos; Mendes, Daniela; Câmara, Andréa; Figueiredo, Jose

2010-03-01

The purpose of this case report is to describe a nonsurgical endodontic treatment of a mandibular left second premolar with two separate roots and three distinct root canals. In endodontics, the possible existence of extra canals must be considered before endodontic treatment is instituted. A wide morphological variation of the root canal system is known to exist. A 36-year-old male patient was referred for endodontic treatment on the left mandibular second premolar. Radiographic examination of the involved tooth revealed an unusual, complex root canal anatomy. There was an irregular root morphology consisting of two distinct roots and three canals. This case report describes the successful nonsurgical endodontic treatment of a mandibular left second premolar with two separate roots and three distinct root canals filled using size 35 Thermafil gutta-percha carriers and AH Plus sealer. On the one-year follow-up radiograph, the tooth was asymptomatic, confirming adequate healing with no complications. Even in a tooth with an extremely complex root canal morphology, conventional endodontic treatment without surgical intervention can result in adequate healing without any complications.

Surgical management of vertical root fractures for posterior teeth: report of four cases.

PubMed

Floratos, Spyros G; Kratchman, Samuel I

2012-04-01

The objective of this article was to present a surgical treatment option for teeth with incomplete vertical root fracture in maxillary and mandibular posterior teeth. Four cases are presented in which 1 endodontically treated maxillary or mandibular molar had an incomplete vertical root fracture involving 1 of the roots. The tooth underwent a flap elevation procedure to visualize the pattern of bone loss and assess the extent of root fracture. The fracture line was eliminated by resecting the root in a beveled manner, after which root-end preparation and root-end filling were performed by using mineral trioxide aggregate. The osteotomy was covered with an absorbable collagen membrane. Cases were followed up for 8-24 months after surgery. The procedure was shown to be predictable and successful in this series. Root length was preserved, and tooth extraction was avoided. The microsurgical treatment option for multirooted teeth with incomplete vertical root fracture resulted in long-term clinical success. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

A new approach to the treatment of true-combined endodontic-periodontic lesions by the guided tissue regeneration technique.

PubMed

Tseng, C C; Harn, W M; Chen, Y H; Huang, C C; Yuan, K; Huang, P H

1996-12-01

Clinicians often have difficulty in the diagnosis and treatment of the combined endodontal and periodontal (endo-perio) lesion. A case of an endo-perio true-combined lesion on a maxillary premolar was first treated with conventional endodontic therapy. Periodontal surgery was then completed, which included scaling and root planing and apical curettage on the tooth. The facial bony defect was then filled with a decalcified freeze-dried bone allograft mixed with tetracycline powder. A non-resorbable Teflon membrane was then used to cover the bone material and the periodontal flap sutured over this. This combined treatment resulted in minimal probing depth (2 mm), maximal clinical attachment gain (8 mm), as well as radiographic evidence of alveolar bone gain. This case report demonstrates that proper diagnosis, followed by removal of etiological factors and utilizing the guided tissue regeneration technique combined with osseous grafting, will restore health and function to a tooth with severe attachment loss caused by an endo-perio lesion.

Chromoplasts ultrastructure and estimated carotene content in root secondary phloem of different carrot varieties.

PubMed

Kim, Ji Eun; Rensing, Kim H; Douglas, Carl J; Cheng, Kimberly M

2010-02-01

There have been few studies on quantifying carotenoid accumulation in carrots, and none have taken the comparative approach. The abundance and distribution of carotenes in carrot roots of three varieties, white, orange, and high carotene mass (HCM) were compared using light and transmission electron microscopy (TEM). Light microscopy has indicated that, in all three varieties, carotenes were most abundant in the secondary phloem and this area was selected for further TEM analysis. While carotenes were extracted during the fixation process for TEM, the high-pressure freezing technique we employed preserved the spaces (CS) left behind by the extracted carotene crystals. Chromoplasts from the HCM variety contained significantly (P < 0.05) more CS than chromoplasts from the orange variety. Chromoplasts from the white variety had few or no CS. There was no significant difference between the HCM and orange varieties in the number of chromoplasts per unit area, but the white variety had significantly (P < 0.05) fewer chromoplasts than the other two varieties. A large number of starch-filled amyloplasts was observed in secondary phloem of the white variety but these were not found in the other two varieties. The results from this comparative approach clearly define the subcellular localization of carotenoids in carrot roots and suggest that while the HCM genotype was selectively bred for increased carotene content, this selection did not lead to increased numbers of carotene-containing chromoplasts but rather greater accumulation of carotene per chromoplast. Furthermore, the results confirm that roots of the white carrot variety retain residual amounts of carotene.

Medial Meniscus Posterior Root Repair Using a Transtibial Technique.

PubMed

Woodmass, Jarret M; Mohan, Rohith; Stuart, Michael J; Krych, Aaron J

2017-06-01

The meniscal roots are critical in maintaining the normal shock absorbing function of the meniscus. If a meniscal root tear is left untreated, meniscal extrusion can occur rendering the meniscus nonfunctional resulting in degenerative arthritis. Two main repair techniques are described: (1) suture anchors (direct fixation) and (2) sutures pulled through a tibial tunnel (indirect fixation). Meniscal root repair using a suture anchor technique is technically challenging requiring a posterior portal and a curved suture passing device that can be difficult to manipulate within the knee. We present a technique for posterior medial meniscus root repair using 3 sutures (1 leader, 2 cinch), standard arthroscopy portals, and transtibial fixation. Overall, this technique simplifies a challenging procedure and allows for familiarity and efficiency.

Effect of incremental filling technique on adhesion of light-cured resin composite to cavity floor.

PubMed

Chikawa, Hirokazu; Inai, Norimichi; Cho, Eitetsu; Kishikawa, Ryuzo; Otsuki, Masayuki; Foxton, Richard M; Tagami, Junji

2006-09-01

The purpose of this study was to evaluate the effect of various incremental filling techniques on adhesion between composite and cavity floor using light-cured resin composite. Black ABS resin and hybrid resin composite were used as mold materials--instead of dentin--for the preparation of cavities, and standardized to 5x5x5 mm. Each cavity was then treated with a bonding system (Clearfil SE bond). Resin composite (Clearfil Photo Core) was placed on the bonding resin using different incremental filling techniques or in bulk and irradiated for a total of 80 seconds using a halogen light unit. Specimens were subjected to the micro-tensile bond test at a crosshead speed of 1 mm/min. Data were analyzed by two-way ANOVA. The results indicated that an incremental filling technique was more effective in improving adhesion to the cavity floor than a bulk filling technique.

Hand and nickel-titanium root canal instrumentation performed by dental students: a micro-computed tomographic study.

PubMed

Peru, M; Peru, C; Mannocci, F; Sherriff, M; Buchanan, L S; Pitt Ford, T R

2006-02-01

The aim of this study was to evaluate root canals instrumented by dental students using the modified double-flared technique, nickel-titanium (NiTi) rotary System GT files and NiTi rotary ProTaper files by micro-computed tomography (MCT). A total of 36 root canals from 18 mesial roots of mandibular molar teeth were prepared; 12 canals were prepared with the modified double-flared technique, using K-flexofiles and Gates-Glidden burs; 12 canals were prepared using System GT and 12 using ProTaper rotary files. Each root was scanned using MCT preoperatively and postoperatively. At the coronal and mid-root sections, System GT and ProTaper files produced significantly less enlarged canal cross-sectional area, volume and perimeter than the modified double-flared technique (P < 0.05). In the mid-root sections there was significantly less thinning of the root structure towards the furcation with System GT and ProTaper (P < 0.05). The rotary techniques were both three times faster than the modified double-flared technique (P < 0.05). Qualitative evaluation of the preparations showed that both ProTaper and System GT were able to prepare root canals with little or no procedural error compared with the modified double-flared technique. Under the conditions of this study, inexperienced dental students were able to prepare curved root canals with rotary files with greater preservation of tooth structure, low risk of procedural errors and much quicker than with hand instruments.

Effect of Metal Artifacts on Detection of Vertical Root Fractures Using Two Cone Beam Computed Tomography Systems.

PubMed

Safi, Yaser; Aghdasi, Mohammad Mehdi; Ezoddini-Ardakani, Fatemeh; Beiraghi, Samira; Vasegh, Zahra

2015-01-01

Vertical root fracture (VRF) is common in endodontically treated teeth. Conventional and digital radiographies have limitations for detection of VRFs. Cone-beam computed tomography (CBCT) offers greater detection accuracy of VRFs in comparison with conventional radiography. This study compared the effects of metal artifacts on detection of VRFs by using two CBCT systems. Eighty extracted premolars were selected and sectioned at the level of the cemento enamel junction (CEJ). After preparation, root canals were filled with gutta-percha. Subsequently, two thirds of the root fillings were removed for post space preparation and a custom-made post was cemented into each canal. The teeth were randomly divided into two groups (n=40). In the test group, root fracture was created with Instron universal testing machine. The control teeth remained intact. CBCT scans of all teeth were obtained with either New Tom VGI or Soredex Scanora 3D. Three observers analyzed the images for detection of VRF. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for VRF detection and percentage of probable cases were calculated for each imaging system and compared using non-parametric tests considering the non-normal distribution of data. The inter-observer reproducibility was calculated using the weighted kappa coefficient. There were no statistically significant differences in sensitivity, specificity, PPV and NPV between the two CBCT systems. The effect of metal artifacts on VRF detection was not significantly different between the two CBCT systems.

Relevance of the clustered regularly interspaced short palindromic repeats of Enterococcus faecalis strains isolated from retreatment root canals on periapical lesions, resistance to irrigants and biofilms

PubMed Central

Tong, Zhongchun; Du, Yu; Ling, Junqi; Huang, Lijia; Ma, Jinglei

2017-01-01

A high prevalence of Enterococcus faecalis (E. faecalis) is observed in teeth with root canal treatment failures. Clustered regularly interspaced short palindromic repeats (CRISPR) are widely distributed in prokaryotes that have adaptive immune systems against mobile elements, including pathogenic genes. The present study investigated the relevance of the CRISPR in E. faecalis strains isolated from retreated root canals on biofilms, periapical lesions and drug resistance. A total of 20 E. faecalis strains were extracted from the root canals of teeth referred for root canal retreatment. CRISPR-Cas loci were identified by two pairs of relevant primers and polymerase chain reaction. The susceptibility of the 20 isolated strains to intracanal irrigants was evaluated by 1- and 5-minute challenges with a mixture of a tetracycline isomer, an acid and a detergent (MTAD), 2% chlorhexidine (CHX) and 5.25% sodium hypochlorite (NaOCl). The microtiter plate assay and crystal violet staining were used to compare the biofilm formation of the E. faecalis isolate strains. Out of the 20 E. faecalis isolate strains, 5 strains that lacked CRISPR-cas determinants exhibited significant periapical lesions. Among the 15 strains containing CRISPR-cas determinants, 8 were isolated from root canals with inadequate fillings and 7 were isolated from root canals without any fillings. The five strains lacking CRISPR-cas loci were observed to be more resistant to MTAD and 2% CHX than the 15 strains that had CRISPR-cas loci. All of the strains exhibited the same susceptibility to 5.25% NaOCl. Furthermore, the 5 strains lacking CRISPR-cas determinants generated more biofilm than the other 15 strains. Thus, the results of the present study suggested that E. faecalis root canal isolates lacking CRISPR-cas exhibit higher resistance to intracanal irrigants, stronger biofilm formation and generate significant periapical lesions. PMID:29285081

Relevance of the clustered regularly interspaced short palindromic repeats of Enterococcus faecalis strains isolated from retreatment root canals on periapical lesions, resistance to irrigants and biofilms.

PubMed

Tong, Zhongchun; Du, Yu; Ling, Junqi; Huang, Lijia; Ma, Jinglei

2017-12-01

A high prevalence of Enterococcus faecalis ( E. faecalis ) is observed in teeth with root canal treatment failures. Clustered regularly interspaced short palindromic repeats (CRISPR) are widely distributed in prokaryotes that have adaptive immune systems against mobile elements, including pathogenic genes. The present study investigated the relevance of the CRISPR in E. faecalis strains isolated from retreated root canals on biofilms, periapical lesions and drug resistance. A total of 20 E. faecalis strains were extracted from the root canals of teeth referred for root canal retreatment. CRISPR-Cas loci were identified by two pairs of relevant primers and polymerase chain reaction. The susceptibility of the 20 isolated strains to intracanal irrigants was evaluated by 1- and 5-minute challenges with a mixture of a tetracycline isomer, an acid and a detergent (MTAD), 2% chlorhexidine (CHX) and 5.25% sodium hypochlorite (NaOCl). The microtiter plate assay and crystal violet staining were used to compare the biofilm formation of the E. faecalis isolate strains. Out of the 20 E. faecalis isolate strains, 5 strains that lacked CRISPR-cas determinants exhibited significant periapical lesions. Among the 15 strains containing CRISPR-cas determinants, 8 were isolated from root canals with inadequate fillings and 7 were isolated from root canals without any fillings. The five strains lacking CRISPR-cas loci were observed to be more resistant to MTAD and 2% CHX than the 15 strains that had CRISPR-cas loci. All of the strains exhibited the same susceptibility to 5.25% NaOCl. Furthermore, the 5 strains lacking CRISPR-cas determinants generated more biofilm than the other 15 strains. Thus, the results of the present study suggested that E. faecalis root canal isolates lacking CRISPR-cas exhibit higher resistance to intracanal irrigants, stronger biofilm formation and generate significant periapical lesions.

Influence of plant roots on electrical resistivity measurements of cultivated soil columns

NASA Astrophysics Data System (ADS)

Maloteau, Sophie; Blanchy, Guillaume; Javaux, Mathieu; Garré, Sarah

2016-04-01

Electrical resistivity methods have been widely used for the last 40 years in many fields: groundwater investigation, soil and water pollution, engineering application for subsurface surveys, etc. Many factors can influence the electrical resistivity of a media, and thus influence the ERT measurements. Among those factors, it is known that plant roots affect bulk electrical resistivity. However, this impact is not yet well understood. The goals of this experiment are to quantify the effect of plant roots on electrical resistivity of the soil subsurface and to map a plant roots system in space and time with ERT technique in a soil column. For this research, it is assumed that roots system affect the electrical properties of the rhizosphere. Indeed the root activity (by transporting ions, releasing exudates, changing the soil structure,…) will modify the rhizosphere electrical conductivity (Lobet G. et al, 2013). This experiment is included in a bigger research project about the influence of roots system on geophysics measurements. Measurements are made on cylinders of 45 cm high and a diameter of 20 cm, filled with saturated loam on which seeds of Brachypodium distachyon (L.) Beauv. are sowed. Columns are equipped with electrodes, TDR probes and temperature sensors. Experiments are conducted at Gembloux Agro-Bio Tech, in a growing chamber with controlled conditions: temperature of the air is fixed to 20° C, photoperiod is equal to 14 hours, photosynthetically active radiation is equal to 200 μmol m-2s-1, and air relative humidity is fixed to 80 %. Columns are fully saturated the first day of the measurements duration then no more irrigation is done till the end of the experiment. The poster will report the first results analysis of the electrical resistivity distribution in the soil columns through space and time. These results will be discussed according to the plant development and other controlled factors. Water content of the soil will also be detailed. Reference Lobet G, Hachez C, Chaumont F, Javaux M, Draye X. Root water uptake and water flow in the soil-root domain. In: Eshel A and Beeckman T, editors. Plant Roots. The Hidden Half. Boca Raton (US):CRC Press,2013. p. 24-1 - 24-13.

Root architecture simulation improves the inference from seedling root phenotyping towards mature root systems.

PubMed

Zhao, Jiangsan; Bodner, Gernot; Rewald, Boris; Leitner, Daniel; Nagel, Kerstin A; Nakhforoosh, Alireza

2017-02-01

Root phenotyping provides trait information for plant breeding. A shortcoming of high-throughput root phenotyping is the limitation to seedling plants and failure to make inferences on mature root systems. We suggest root system architecture (RSA) models to predict mature root traits and overcome the inference problem. Sixteen pea genotypes were phenotyped in (i) seedling (Petri dishes) and (ii) mature (sand-filled columns) root phenotyping platforms. The RSA model RootBox was parameterized with seedling traits to simulate the fully developed root systems. Measured and modelled root length, first-order lateral number, and root distribution were compared to determine key traits for model-based prediction. No direct relationship in root traits (tap, lateral length, interbranch distance) was evident between phenotyping systems. RootBox significantly improved the inference over phenotyping platforms. Seedling plant tap and lateral root elongation rates and interbranch distance were sufficient model parameters to predict genotype ranking in total root length with an RSpearman of 0.83. Parameterization including uneven lateral spacing via a scaling function substantially improved the prediction of architectures underlying the differently sized root systems. We conclude that RSA models can solve the inference problem of seedling root phenotyping. RSA models should be included in the phenotyping pipeline to provide reliable information on mature root systems to breeding research. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

The failures of root canal preparation with hand ProTaper

PubMed Central

Bătăiosu, Marilena; Diaconu, Oana; Moraru, Iren; Dăguci, C.; Ţuculină, Mihaela; Dăguci, Luminiţa; Gheorghiţă, Lelia

2012-01-01

The failures of root canal preparation are due to some anatomical deviation (canal in “C” or “S”) and some technique errors. The technique errors are usually present in canal root cleansing and shaping stage and are the result of endodontic treatment objectives deviation. Objectives: Our study was made on technique errors while preparing the canal roots with hand ProTaper. Methodology: Our study was made “in vitro” on 84 extracted teeth (molars, premolars, incisors and canines). The canal root of these teeth were cleansed and shaped with hand ProTaper by crown-down technique and canal irrigation with NaOCl(2,5%). The dental preparation control was made by X-ray. Results: During canal root preparation some failures were observed like: canal root overinstrumentation, zipping and stripping phenomenon, discarded and/or fractured instruments. Conclusions: Hand ProTaper represents a revolutionary progress of endodontic treatment, but a deviation from accepted rules of canal root instrumentation can lead to failures of endodontic treatment. PMID:24778848

Low Light Diagnostics in Thin-Film Photovoltaics

NASA Astrophysics Data System (ADS)

Shvydka, Diana; Karpov, Victor; Compaan, Alvin

2003-03-01

We study statistics of the major photovoltaic (PV) parameters such as open circuit voltage, short circuit current and fill factor vs. light intensity on a set of nominally identical CdTe/CdS solar cells. We found the most probable parameter values to change with the light intensity as predicted by the standard diode model, while their relative fluctuations increase dramatically under low light. The crossover light intensity is found below which the relative fluctuations of the PV parameters diverge inversely proportional to the square root of the light intensity. We propose a model where the observed fluctuations are due to lateral nonuniformities in the device structure. In particular, the crossover is attributed to the lateral nonuniformity screening length exceeding the device size. >From the practical standpoint, our study introduces a simple uniformity diagnostic technique.

21 CFR 872.3850 - Gutta percha.

Code of Federal Regulations, 2010 CFR

2010-04-01

... DENTAL DEVICES Prosthetic Devices § 872.3850 Gutta percha. (a) Identification. Gutta percha is a device made from coagulated sap of certain tropical trees intended to fill the root canal of a tooth. The...

Percentage exposure of root dentin collagen after application of two irrigation protocols with manual or rotary instrumentation and two methacrylate resin-based sealers.

PubMed

González-López, Santiago; Martín-Altuve, Ernesto; Bolaños-Carmona, Victoria; Sánchez-Sánchez, Purificación; Rodríguez-Navarro, Alejandro

2013-10-01

To compare the percentage of collagen exposed in dentin root thirds after two irrigation protocols with manual or rotary instrumentation using two methacrylate resin-based sealers. Forty-eight single-root human teeth were prepared with manual (n = 24) or nickeltitanium ProFile rotary (n = 24) instrumentation, using 5% NaOCl between instruments and 5 ml 17% EDTA as final irrigant or 20% citric acid + 2% chlorhexidine (CHX) between instruments and as the final irrigant. RealSeal or EndoREZ were used as filling materials. One 1-mm slice per third was abraded and stained with Masson's trichrome method. Mean exposed collagen values were obtained in four areas from each section (at 60X magnification) and a complete factorial ANOVA was used to analyze the influence of the study variables. Non-parametric Mann-Whitney's test was used to compare groups. Differences with p < 0.05 were considered significant. A significantly higher percentage of collagen was exposed in all thirds with the use of the 20% citric acid + 2% CHX protocol with rotary vs manual instrumentation, but percent collagen exposed did not differ as a function of the filling material. After the 5% NaOCl + 17% EDTA protocol, the percentage of collagen exposed did not differ between rotary and manual instrumentation but was higher with the use of RealSeal. The highest percentage exposure of collagen was with 20% citric acid + 2% CHX using rotary instrumentation, regardless of the filling material.

Efficacy of two rotary retreatment systems in removing Gutta-percha and sealer during endodontic retreatment with or without solvent: A comparative in vitro study

PubMed Central

Bhagavaldas, Moushmi Chalakkarayil; Diwan, Abhinav; Kusumvalli, S.; Pasha, Shiraz; Devale, Madhuri; Chava, Deepak Chowdary

2017-01-01

Objectives: The aim of this in vitro study was to compare the efficacy of two retreatment rotary systems in the removal of Gutta-percha (GP) and sealer from the root canal walls with or without solvent. Materials and Methods: Forty-eight extracted human mandibular first premolars were prepared and obturated with GP and AH Plus sealer. Samples were then randomly divided into four groups. Group I was retreated with MtwoR rotary system without solvent, Group II was retreated with MtwoR rotary system with Endosolv R as the solvent, Group III with D-RaCe rotary system without solvent, and Group IV with D-RaCe rotary system and Endosolv R solvent. The cleanliness of canal walls was determined by stereomicroscope (×20) and AutoCAD software. Kruskal–Wallis test and Mann–Whitney U-test were used to compare the data. Results: Results showed that none of the retreatment systems used in this study was able to completely remove the root canal filling material. D-RaCe with or without solvent showed significantly (P > 0.05) less filling material at all levels compared to MtwoR with/without solvent. Conclusion: Within the limitation of the current study, D-RaCe rotary retreatment system is more effective in removing filling material from root canal walls when compared to MtwoR rotary retreatment system. PMID:28761246

Plant root and shoot dynamics during subsurface obstacle interaction

NASA Astrophysics Data System (ADS)

Conn, Nathaniel; Aguilar, Jeffrey; Benfey, Philip; Goldman, Daniel

As roots grow, they must navigate complex underground environments to anchor and retrieve water and nutrients. From gravity sensing at the root tip to pressure sensing along the tip and elongation zone, the complex mechanosensory feedback system of the root allows it to bend towards greater depths and avoid obstacles of high impedance by asymmetrically suppressing cell elongation. Here we investigate the mechanical and physiological responses of roots to rigid obstacles. We grow Maize, Zea mays, plants in quasi-2D glass containers (22cm x 17cm x 1.4cm) filled with photoelastic gel and observe that, regardless of obstacle interaction, smaller roots branch off the primary root when the upward growing shoot (which contains the first leaf) reaches an average length of 40 mm, coinciding with when the first leaf emerges. However, prior to branching, contacts with obstacles result in reduced root growth rates. The growth rate of the root relative to the shoot is sensitive to the angle of the obstacle surface, whereby the relative root growth is greatest for horizontally oriented surfaces. We posit that root growth is prioritized when horizontal obstacles are encountered to ensure anchoring and access to nutrients during later stages of development. NSF Physics of Living Systems.

Analysis techniques for multivariate root loci. [a tool in linear control systems

NASA Technical Reports Server (NTRS)

Thompson, P. M.; Stein, G.; Laub, A. J.

1980-01-01

Analysis and techniques are developed for the multivariable root locus and the multivariable optimal root locus. The generalized eigenvalue problem is used to compute angles and sensitivities for both types of loci, and an algorithm is presented that determines the asymptotic properties of the optimal root locus.

Radiographic comparison of apical root resorption after orthodontic treatment between bidimensional and Roth straight-wire techniques

PubMed Central

Zawawi, Khalid H; Malki, Ghadah A

2014-01-01

Objective: The aim of this study was to compare the amount of root resorption after orthodontic treatment between the bidimensional and the Roth straight-wire techniques. Another objective was to compare the amount of root resorption in the whole sample studied and record the prevalence of root resorption. Materials and Methods: The sample consisted of 40 patients (age ranged between 11 and 18 years) with Angle Class II division 1 malocclusions, treated nonextraction. Twenty patients were treated with bidimensional technique and 20 with a 0.018-inch Roth straight-wire technique. Root lengths of the maxillary incisors were measured on pre- and post-treatment periapical radiographs. Results: The results demonstrated that the bidimensional and Roth straight-wire groups showed significant root resorption after treatment, 1.11 (0.17) and 0.86 (0.05), respectively, P < 0.001. When comparing the amount of root shortening between the bidimensional and Roth straight-wire groups, there was no significant difference between the mean change from pre- to post-treatment between bidimensional group (mean = 1.00 ± 1.34) and Roth straight-wire group (mean = 0.88 ± 0.86), P = 0.63. Considering the whole sample, there was no root resoprtion in 32.5% of the analysed teeth. There was only mild resorption in 56.2%, moderate in 8.8% and severe in only 2.5% of the teeth. Conclusions: Treatment with the bidimensional technique did not produce an increase in the amount of root resorption. The prevalence and amount of root resorption was similar between bidimensional and Roth straight-wire techniques. PMID:25426453

Radiographic comparison of apical root resorption after orthodontic treatment between bidimensional and Roth straight-wire techniques.

PubMed

Zawawi, Khalid H; Malki, Ghadah A

2014-10-01

The aim of this study was to compare the amount of root resorption after orthodontic treatment between the bidimensional and the Roth straight-wire techniques. Another objective was to compare the amount of root resorption in the whole sample studied and record the prevalence of root resorption. The sample consisted of 40 patients (age ranged between 11 and 18 years) with Angle Class II division 1 malocclusions, treated nonextraction. Twenty patients were treated with bidimensional technique and 20 with a 0.018-inch Roth straight-wire technique. Root lengths of the maxillary incisors were measured on pre- and post-treatment periapical radiographs. The results demonstrated that the bidimensional and Roth straight-wire groups showed significant root resorption after treatment, 1.11 (0.17) and 0.86 (0.05), respectively, P < 0.001. When comparing the amount of root shortening between the bidimensional and Roth straight-wire groups, there was no significant difference between the mean change from pre- to post-treatment between bidimensional group (mean = 1.00 ± 1.34) and Roth straight-wire group (mean = 0.88 ± 0.86), P = 0.63. Considering the whole sample, there was no root resoprtion in 32.5% of the analysed teeth. There was only mild resorption in 56.2%, moderate in 8.8% and severe in only 2.5% of the teeth. Treatment with the bidimensional technique did not produce an increase in the amount of root resorption. The prevalence and amount of root resorption was similar between bidimensional and Roth straight-wire techniques.

Antibacterial Properties Associated with Chitosan Nanoparticle Treatment on Root Dentin and 2 Types of Endodontic Sealers.

PubMed

Del Carpio-Perochena, Aldo; Kishen, Anil; Shrestha, Annie; Bramante, Clovis Monteiro

2015-08-01

The aim of this study was to evaluate the efficacy of carboxymethyl chitosan (CMCS) and chitosan nanoparticles (CNps) to inactivate bacteria and prevent biofilm formation at sealer-dentin interfaces. The study was divided into 3 stages: first stage, the experiment was conducted to analyze the antibacterial properties of CMCS in different formulations against biofilms; second stage, direct-contact and membrane-restricted methods were used to evaluate the antibacterial properties of an epoxy resin (ThermaSeal Plus; Dentsply Tulsa Dental, Tulsa, OK) and calcium silicate (MTA Fillapex; Angelus SA, Londrina, PR, Brazil) based-sealers with or without CNps; and third stage, biofilm formation at the sealer dentin interfaces of root dentin treated with CMCS and filled with gutta-percha and CNp incorporated sealer were analyzed after 1- and 4-week aging periods. The samples were treated and filled as follows: (1) distilled water: unaltered sealer (control group), (2) CMCS: sealer+CNps (CMCS group), and (3) CMCS/rose bengal: sealer+CNps (CMCS/RB group). Enterococcus faecalis was used to infect all the samples. Microbiological and microscopic analyses were used to assess the antibacterial characteristics. CMCS-based treatments effectively killed bacteria adherent on root dentin (P < .05). The addition of CNps to ThermaSeal enhanced its antibacterial ability by direct-contact and membrane-restricted tests (P < .05). The CNp incorporation significantly increased the antibacterial efficacy of root canal sealers even after a 4-week aging time (P < .05). This study highlighted the ability of CMCS to disinfect root canal dentin and inhibit bacterial adhesion. CNps in root canal sealers are capable of maintaining their antibacterial activity even after prolonged aging. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Comparison of Gutta Percha Filling Techniques. Part 2. Three Chloroform-Gutta Percha Filling Techniques.

DTIC Science & Technology

1980-06-01

in evaluators and the evaluation method. Also in Goldman’s study reagents, nitric acid and sodium hypochlorite , were used in retrieving the gutta...Inlo Di-5r7W~f~ IU* Report) DTIC illE LECTE f_ IS. KEY WORDS (Conthue on revere* side It necessay and Identify by block numbei) -. , endodontics ...TECHNIQUES. PART 2: THREE CHLOROFORM-GUTTA PERCHA FILLING TECHNIQUES M. Wong, DDS Resident, Endodontics Dept. of Dentistry - PO Box 59 Madigan Army Medical

Classroom Modified Split-Root Technique and Its Application in a Plant Habitat Selection Experiment at the College Level

ERIC Educational Resources Information Center

Elliott, Shannon S.; Winter, Peggy A.

2011-01-01

The split-root technique produces a plant with two equal root masses. Traditionally, the two root masses of the single plant are cultivated in adjacent pots with or without roots from competitors for the purpose of elucidating habitat preferences. We have tailored this technology for the classroom, adjusting protocols to match resources and time…

Effect of ultrasonic agitation on push-out bond strength and adaptation of root-end filling materials

PubMed Central

2018-01-01

Objectives This study evaluated the effect of ultrasonic agitation of mineral trioxide aggregate (MTA), calcium silicate-based cement (CSC), and Sealer 26 (S26) on adaptation at the cement/dentin interface and push-out bond strength. Materials and Methods Sixty maxillary canines were divided into 6 groups (n = 10): MTA, S26, and CSC, with or without ultrasonic activation (US). After obturation, the apical portions of the teeth were sectioned, and retrograde cavities were prepared and filled with cement by hand condensation. In the US groups, the cement was activated for 60 seconds: 30 seconds in the mesio-distal direction and 30 seconds in the buccal-lingual direction, using a mini Irrisonic insert coupled with the ultrasound transducer. After the materials set, 1.5-mm thick sections were obtained from the apexes. The presence of gaps and the bond between cement and dentin were analyzed using low-vacuum scanning electron microscopy. Push-out bond strength was measured using a universal testing machine. Results Ultrasonic agitation increased the interfacial adaptation of the cements. The S26 US group showed a higher adaptation value than MTA (p < 0.05). US improved the push-out bond strength for all the cements (p < 0.05). Conclusions The US of retrograde filling cements enhanced the bond to the dentin wall of the root-end filling materials tested. PMID:29765903

Effect of ultrasonic agitation on push-out bond strength and adaptation of root-end filling materials.

PubMed

Alcalde, Murilo Priori; Vivan, Rodrigo Ricci; Marciano, Marina Angélica; Duque, Jussaro Alves; Fernandes, Samuel Lucas; Rosseto, Mariana Bailo; Duarte, Marco Antonio Hungaro

2018-05-01

This study evaluated the effect of ultrasonic agitation of mineral trioxide aggregate (MTA), calcium silicate-based cement (CSC), and Sealer 26 (S26) on adaptation at the cement/dentin interface and push-out bond strength. Sixty maxillary canines were divided into 6 groups ( n = 10): MTA, S26, and CSC, with or without ultrasonic activation (US). After obturation, the apical portions of the teeth were sectioned, and retrograde cavities were prepared and filled with cement by hand condensation. In the US groups, the cement was activated for 60 seconds: 30 seconds in the mesio-distal direction and 30 seconds in the buccal-lingual direction, using a mini Irrisonic insert coupled with the ultrasound transducer. After the materials set, 1.5-mm thick sections were obtained from the apexes. The presence of gaps and the bond between cement and dentin were analyzed using low-vacuum scanning electron microscopy. Push-out bond strength was measured using a universal testing machine. Ultrasonic agitation increased the interfacial adaptation of the cements. The S26 US group showed a higher adaptation value than MTA ( p < 0.05). US improved the push-out bond strength for all the cements ( p < 0.05). The US of retrograde filling cements enhanced the bond to the dentin wall of the root-end filling materials tested.

A global Fine-Root Ecology Database to address below-ground challenges in plant ecology

DOE PAGES

Iversen, Colleen M.; McCormack, M. Luke; Powell, A. Shafer; ...

2017-02-28

Variation and tradeoffs within and among plant traits are increasingly being harnessed by empiricists and modelers to understand and predict ecosystem processes under changing environmental conditions. And while fine roots play an important role in ecosystem functioning, fine-root traits are underrepresented in global trait databases. This has hindered efforts to analyze fine-root trait variation and link it with plant function and environmental conditions at a global scale. This Viewpoint addresses the need for a centralized fine-root trait database, and introduces the Fine-Root Ecology Database (FRED, http://roots.ornl.gov) which so far includes > 70 000 observations encompassing a broad range of rootmore » traits and also includes associated environmental data. FRED represents a critical step toward improving our understanding of below-ground plant ecology. For example, FRED facilitates the quantification of variation in fine-root traits across root orders, species, biomes, and environmental gradients while also providing a platform for assessments of covariation among root, leaf, and wood traits, the role of fine roots in ecosystem functioning, and the representation of fine roots in terrestrial biosphere models. There has been a continued input of observations into FRED to fill gaps in trait coverage will improve our understanding of changes in fine-root traits across space and time.« less

A global Fine-Root Ecology Database to address below-ground challenges in plant ecology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iversen, Colleen M.; McCormack, M. Luke; Powell, A. Shafer

Variation and tradeoffs within and among plant traits are increasingly being harnessed by empiricists and modelers to understand and predict ecosystem processes under changing environmental conditions. And while fine roots play an important role in ecosystem functioning, fine-root traits are underrepresented in global trait databases. This has hindered efforts to analyze fine-root trait variation and link it with plant function and environmental conditions at a global scale. This Viewpoint addresses the need for a centralized fine-root trait database, and introduces the Fine-Root Ecology Database (FRED, http://roots.ornl.gov) which so far includes > 70 000 observations encompassing a broad range of rootmore » traits and also includes associated environmental data. FRED represents a critical step toward improving our understanding of below-ground plant ecology. For example, FRED facilitates the quantification of variation in fine-root traits across root orders, species, biomes, and environmental gradients while also providing a platform for assessments of covariation among root, leaf, and wood traits, the role of fine roots in ecosystem functioning, and the representation of fine roots in terrestrial biosphere models. There has been a continued input of observations into FRED to fill gaps in trait coverage will improve our understanding of changes in fine-root traits across space and time.« less

Multi-frequency electrical impedance tomography as a non-invasive tool to characterize and monitor crop root systems

NASA Astrophysics Data System (ADS)

Weigand, Maximilian; Kemna, Andreas

2017-02-01

A better understanding of root-soil interactions and associated processes is essential in achieving progress in crop breeding and management, prompting the need for high-resolution and non-destructive characterization methods. To date, such methods are still lacking or restricted by technical constraints, in particular the charactization and monitoring of root growth and function in the field. A promising technique in this respect is electrical impedance tomography (EIT), which utilizes low-frequency (< 1 kHz)- electrical conduction- and polarization properties in an imaging framework. It is well established that cells and cell clusters exhibit an electrical polarization response in alternating electric-current fields due to electrical double layers which form at cell membranes. This double layer is directly related to the electrical surface properties of the membrane, which in turn are influenced by nutrient dynamics (fluxes and concentrations on both sides of the membranes). Therefore, it can be assumed that the electrical polarization properties of roots are inherently related to ion uptake and translocation processes in the root systems. We hereby propose broadband (mHz to hundreds of Hz) multi-frequency EIT as a non-invasive methodological approach for the monitoring and physiological, i.e., functional, characterization of crop root systems. The approach combines the spatial-resolution capability of an imaging method with the diagnostic potential of electrical-impedance spectroscopy. The capability of multi-frequency EIT to characterize and monitor crop root systems was investigated in a rhizotron laboratory experiment, in which the root system of oilseed plants was monitored in a water-filled rhizotron, that is, in a nutrient-deprived environment. We found a low-frequency polarization response of the root system, which enabled the successful delineation of its spatial extension. The magnitude of the overall polarization response decreased along with the physiological decay of the root system due to the stress situation. Spectral polarization parameters, as derived from a pixel-based Debye decomposition analysis of the multi-frequency imaging results, reveal systematic changes in the spatial and spectral electrical response of the root system. In particular, quantified mean relaxation times (of the order of 10 ms) indicate changes in the length scales on which the polarization processes took place in the root system, as a response to the prolonged induced stress situation. Our results demonstrate that broadband EIT is a capable, non-invasive method to image root system extension as well as to monitor changes associated with the root physiological processes. Given its applicability on both laboratory and field scales, our results suggest an enormous potential of the method for the structural and functional imaging of root systems for various applications. This particularly holds for the field scale, where corresponding methods are highly desired but to date are lacking.

Dynamics of air gap formation around roots with changing soil water content.

NASA Astrophysics Data System (ADS)

Vetterlein, D.; Carminati, A.; Weller, U.; Oswald, S.; Vogel, H.-J.

2009-04-01

Most models regarding uptake of water and nutrients from soil assume intimate contact between roots and soil. However, it is known for a long time that roots may shrink under drought conditions. Due to the opaque nature of soil this process could not be observed in situ until recently. Combining tomography of the entire sample (field of view of 16 x 16 cm, pixel side 0.32 mm) with local tomography of the soil region around roots (field of view of 5 x 5 cm, pixel side 0.09 mm), the high spatial resolution required to image root shrinkage and formation of air-filled gaps around roots could be achieved. Applying this technique and combining it with microtensiometer measurements, measurements of plant gas exchange and microscopic assessment of root anatomy, a more detailed study was conducted to elucidate at which soil matric potential roots start to shrink in a sandy soil and which are the consequences for plant water relations. For Lupinus albus grown in a sandy soil tomography of the entire root system and of the interface between taproot and soil was conducted from day 11 to day 31 covering two drying cycles. Soil matric potential decreased from -36 hPa at day 11 after planting to -72, -251, -429 hPa, on day 17, 19, 20 after planting. On day 20 an air gap started to occur around the tap root and extended further on day 21 with matric potential below -429 hPa (equivalent to 5 v/v % soil moisture). From day 11 to day 21 stomatal conductivity decreased from 467 to 84 mmol m-2 s-1, likewise transpiration rate decreased and plants showed strong wilting symptoms on day 21. Plants were watered by capillary rise on day 21 and recovered completely within a day with stomatal conductivity increasing to 647 mmol m-2 s-1. During a second drying cycle, which was shorter as plants continuously increased in size, air gap formed again at the same matric potential. Plant stomatal conductance and transpiration decreased in a similar fashion with decreasing matric potential and appearance of air gap as during the first cycle. Microscopic assessment of the tap root at day 31 showed that secondary thickening of the taproot occurred all along the region of interest observed during X-ray tomography. A large part of the cross sections consists of lignified tissue; no root hairs could be observed along the tap root. Gaps are expected to reduce water transfers between soil and roots. Opening and closing of gaps may help plants to prevent water loss when the soil dries, and to restore the soil-root continuity when water becomes available.

Estimation of root zone storage capacity at the catchment scale using improved Mass Curve Technique

NASA Astrophysics Data System (ADS)

Zhao, Jie; Xu, Zongxue; Singh, Vijay P.

2016-09-01

The root zone storage capacity (Sr) greatly influences runoff generation, soil water movement, and vegetation growth and is hence an important variable for ecological and hydrological modelling. However, due to the great heterogeneity in soil texture and structure, there seems to be no effective approach to monitor or estimate Sr at the catchment scale presently. To fill the gap, in this study the Mass Curve Technique (MCT) was improved by incorporating a snowmelt module for the estimation of Sr at the catchment scale in different climatic regions. The "range of perturbation" method was also used to generate different scenarios for determining the sensitivity of the improved MCT-derived Sr to its influencing factors after the evaluation of plausibility of Sr derived from the improved MCT. Results can be showed as: (i) Sr estimates of different catchments varied greatly from ∼10 mm to ∼200 mm with the changes of climatic conditions and underlying surface characteristics. (ii) The improved MCT is a simple but powerful tool for the Sr estimation in different climatic regions of China, and incorporation of more catchments into Sr comparisons can further improve our knowledge on the variability of Sr. (iii) Variation of Sr values is an integrated consequence of variations in rainfall, snowmelt water and evapotranspiration. Sr values are most sensitive to variations in evapotranspiration of ecosystems. Besides, Sr values with a longer return period are more stable than those with a shorter return period when affected by fluctuations in its influencing factors.

Resistance to compression of weakened roots subjected to different root reconstruction protocols

PubMed Central

ZOGHEIB, Lucas Villaça; SAAVEDRA, Guilherme de Siqueira Ferreira Anzaloni; CARDOSO, Paula Elaine; VALERA, Márcia Carneiro; de ARAÚJO, Maria Amélia Máximo

2011-01-01

Objective This study evaluated, in vitro, the fracture resistance of human non-vital teeth restored with different reconstruction protocols. Material and methods Forty human anterior roots of similar shape and dimensions were assigned to four groups (n=10), according to the root reconstruction protocol: Group I (control): non-weakened roots with glass fiber post; Group II: roots with composite resin by incremental technique and glass fiber post; Group III: roots with accessory glass fiber posts and glass fiber post; and Group IV: roots with anatomic glass fiber post technique. Following post cementation and core reconstruction, the roots were embedded in chemically activated acrylic resin and submitted to fracture resistance testing, with a compressive load at an angle of 45º in relation to the long axis of the root at a speed of 0.5 mm/min until fracture. All data were statistically analyzed with bilateral Dunnett's test (α=0.05). Results Group I presented higher mean values of fracture resistance when compared with the three experimental groups, which, in turn, presented similar resistance to fracture among each other. None of the techniques of root reconstruction with intraradicular posts improved root strength, and the incremental technique was suggested as being the most recommendable, since the type of fracture that occurred allowed the remaining dental structure to be repaired. Conclusion The results of this in vitro study suggest that the healthy remaining radicular dentin is more important to increase fracture resistance than the root reconstruction protocol. PMID:22231002

Comparison of marginal adaptation of mineral trioxide aggregate, glass ionomer cement and intermediate restorative material as root-end filling materials, using scanning electron microscope: An in vitro study

PubMed Central

Gundam, Sirisha; Patil, Jayaprakash; Venigalla, Bhuvan Shome; Yadanaparti, Sravanthi; Maddu, Radhika; Gurram, Sindhura Reddy

2014-01-01

Aim: The present study compares the marginal adaption of Mineral Trioxide Aggregate (MTA), Glass Ionomer Cement (GIC) and Intermediate Restorative Material (IRM) as root-end filling materials in extracted human teeth using Scanning Electron Microscope (SEM). Materials and Methods: Thirty single rooted human teeth were obturated with Gutta-percha after cleaning and shaping. Apical 3 mm of roots were resected and retrofilled with MTA, GIC and IRM. One millimeter transverse section of the retrofilled area was used to study the marginal adaptation of the restorative material with the dentin. Mounted specimens were examined using SEM at approximately 15 Kv and 10-6 Torr under high vacuum condition. At 2000 X magnification, the gap size at the material-tooth interface was recorded at 2 points in microns. Statistical Analysis: One way ANOVA Analysis of the data from the experimental group was carried out with gap size as the dependent variable, and material as independent variable. Results: The lowest mean value of gap size was recorded in MTA group (0.722 ± 0.438 μm) and the largest mean gap in GIC group (1.778 ± 0.697 μm). Conclusion: MTA showed least gap size when compared to IRM and GIC suggesting a better marginal adaptation. PMID:25506146

Prevalence of apical periodontitis and quality of root canal treatment in an adult Saudi population

PubMed Central

Al-Nazhan, Saad A.; Alsaeed, Suliman A.; Al-Attas, Hussan A.; Dohaithem, Abdullah J.; Al-Serhan, Mohamed S.; Al-Maflehi, Nassr S.

2017-01-01

Objectives: To determine the health status of periradicular tissue and the quality of root canal fillings in an adult Saudi population attending dental clinics for the first time. Methods: This cross sectional study was conducted in the dental clinics at King Saud University, Riyadh and other dental centers (Jeddah, Najran, and Albaha City), Kingdom of Saudi Arabia between year 2010 and 2012. Good-quality panoramic radiographs of 926 Saudi subjects (540 males and 386 females)were analyzed based on the gender, age, health status, smoking habits, periapical status of the endodontically treated teeth, technical quality of the root canal fillings, and the presence or absence of coronal restoration. Data were calibrated and statistical analyses were performed using the Statistical Package for the Social Sciences (SPSS Inc., Chicago, IL, USA) version 17. Results: Of the 25,028 teeth examined, 1,556 teeth (6.2%) had apical periodontitis (AP). Male subjects aged over 55 years and females between 36 and 45 years had higher AP. A total of 36 diabetic and 87 smokers subjects had AP. The AP was more common in male diabetics than female (p=0.383), and in female smokers more than male (p=0.44). Only 42.2% of male and 57.7% of female teeth had adequate root canal treatment. Conclusions: Apical periodontitis was significantly related to diabetes, smoking, and inadequate endodontic treatment. PMID:28397949

Influence of root canal instrumentation and obturation techniques on intra-operative pain during endodontic therapy

PubMed Central

Martín-González, Jenifer; Echevarría-Pérez, Marta; Sánchez-Domínguez, Benito; Tarilonte-Delgado, Maria L.; Castellanos-Cosano, Lizett; López-Frías, Francisco J.

2012-01-01

Objective: To analyse the influence of root canal instrumentation and obturation techniques on intra-operative pain experienced by patients during endodontic therapy. Method and Materials: A descriptive cross-sectional study was carried out in Ponferrada and Sevilla, Spain, including 80 patients (46 men and 34 women), with ages ranged from 10 to 74 years, randomly recruited. Patient gender and age, affected tooth, pulpal diagnosis, periapical status, previous NSAID or antibiotic (AB) treatment, and root canal instrumentation and obturation techniques were recorded. After root canal treatment (RCT), patients completed a 10-cm visual analogue scale (VAS) that ranked the level of pain. Results were analysed statistically using the Chi-square and ANOVA tests and logistic regression analysis. Results: The mean pain level during root canal treatment was 2.9 ± 3.0 (median = 2) in a VAS between 0 and 10. Forty percent of patients experienced no pain. Gender, age, arch, previous NSAIDs or AB treatment and anaesthetic type did not influence significantly the pain level (p > 0.05). Pain during root canal treatment was significantly greater in molar teeth (OR = 10.1; 95% C.I. = 1.6 - 63.5; p = 0.013). Root canal instrumentation and obturation techniques did not affect significantly patient’s pain during root canal treatment (p > 0.05). Conclusion: Patients feel more pain when RCT is carried out on molar teeth. The root canal instrumentation and obturation techniques do not affect significantly the patients’ pain during RCT. Key words:Anaesthesia, endodontic pain, pulpitis, root canal instrumentation, root canal obturation, rotary files. PMID:22549694

Endodontic treatment of a maxillary lateral incisor with a perforating internal resorption by using cone beam computed tomography as a diagnostic aid: a case report.

PubMed

Takita, Toshiya; Tsurumachi, Tamotsu; Ogiso, Bunnai

2011-10-01

This case report presents the endodontic treatment of a maxillary right lateral incisor with a perforating internal resorption in a 50-year-old woman. Radiographically, internal resorption appears as a fairly uniform, radiolucent enlargement of the pulp canal and distortion of the original root canal outline. The use of cone beam computed tomography can help the clinician in making a confirmatory diagnosis and determining the treatment plan before undertaking the actual treatment. After cleaning the root canal space and the resorptive defect by mechanic instrumentation, irrigation, and interim calcium hydroxide dressing, the apical third canal was filled with a gutta-percha point by lateral condensation. The resorptive defect was filled with mineral trioxide aggregate. Follow-up radiographs at 3 years showed adequate repair of the resorption, and the tooth remained asymptomatic.

Influence of apical enlargement and complementary canal preparation with the Self-Adjusting File on endotoxin reduction in retreatment cases.

PubMed

Silva, E J N L; Ferreira, V M; Silva, C C; Herrera, D R; De-Deus, G; Gomes, B P

2017-07-01

To compare the effectiveness of large apical preparations and complementary canal preparation with the Self-Adjusting File (SAF) in removing endotoxins from the root canal of teeth with apical periodontitis. Ten single-rooted and single-canaled teeth with post-treatment apical periodontitis were selected. Endotoxin samples were taken after removal of the root filling (S1), after chemomechanical preparation (CMP) using 2.5% NaOCl and an R25 file (S2), after CMP using 2.5% NaOCl and an R40 file (S3) and after complementary CMP using the SAF system (S4). Limulus amebocyte lysate (LAL) was used to measure endotoxin levels. The Friedman and Wilcoxon tests were used to compare endotoxin levels at each clinical intervention (P < 0.05). After root filling removal, endotoxin was detected in 100% of the root canals (S1, 4.84 EU mL -1 ). CMP with the R25 file was able to significantly reduce endotoxin levels (P < 0.05). Increased levels of endotoxin removal were achieved by apical preparation with the R40 file (P < 0.05). Complementary CMP with SAF did not significantly reduce endotoxin levels (P > 0.05) following the use of the R40 instrument. Apical enlargement protocols were effective in significantly reducing endotoxin levels. Complementary preparation with the SAF system failed to eliminate residual endotoxin contents beyond those obtained with the R40 instrument. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Comparison of post-obturation pain experience following one-visit and two-visit root canal treatment on teeth with vital pulps: a randomized controlled trial.

PubMed

Wang, C; Xu, P; Ren, L; Dong, G; Ye, L

2010-08-01

To compare the incidence and intensity of post-obturation pain after one- or two-visit root canal treatment (RCT) on anterior teeth with vital pulps and a single root and canal in a randomized controlled trial. One hundred patients requiring RCT on permanent anterior teeth with vital pulps preoperatively were included. The patients were assigned randomly into two groups of 50 patients each. After local anaesthesia, isolation, access and pulp extirpation, the canals of all teeth were prepared using engine-driven rotary ProTaper nickel-titanium instruments in a crown-down technique and irrigated with 2.5% NaOCl. The teeth in group 1 (n = 50) were filled with AH Plus sealer and gutta-percha using a lateral compaction technique at the first visit, whilst those in group 2 (n = 50) were medicated with a calcium hydroxide paste, a sterile dry cotton pellet and Caviton and scheduled for a second visit 7 days later. A modified verbal descriptor scale was used to measure preoperative pain and post-obturation pain at 6, 24, 48 h and 1 week after operation. Chi-square tests and independent-sample T-tests were used to compare the incidence and intensity of post-obturation pain of two groups at each interval. Eleven patients were excluded from the study as they failed to follow the scheduled revisit or their selected teeth had more than one root canal. Data were obtained from the remaining 89 patients. Forty-three patients were undergoing one-visit treatment (group 1) and 46 undergoing two-visit treatment (group 2). Most patients in both groups reported no pain or only slight pain within each post-obturation interval, only one in group 1 and one in group 2 had flare-ups and slight swelling. There was no statistically significant difference in the incidence and intensity of post-obturation pain experienced by two groups. The incidence and intensity of post-obturation pain experience following one- or two-visit RCT on teeth with vital pulps and a single canal were not significantly different.

Ground penetrating radar (GPR) detects fine roots of agricultural crops in the field

Treesearch

Xiuwei Liu; Xuejun Dong; Qingwu Xue; Daniel I. Leskovar; John Jifon; John R. Butnor; Thomas Marek

2018-01-01

Aim Ground penetrating radar (GPR) as a non-invasive technique is widely used in coarse root detection. However, the applicability of the technique to detect fine roots of agricultural crops is unknown. The objective of this study was to assess the feasibility of utilizing GPR to detect fine roots in the field.

Comparative evaluation of antimicrobial efficacy of various root canal filling materials along with aloevera used in primary teeth: a microbiological study.

PubMed

Kriplani, R; Thosar, N; Baliga, M S; Kulkarni, P; Shah, N; Yeluri, R

2013-01-01

this study was conducted to evaluate the antimicrobial effectiveness of 6 root canal filling materials and a negative control agent against 18 strains of bacteria isolated from infected root canals of primary molar teeth using agar diffusion assay. Aloevera with sterile water Zinc oxide and Eugenol, Zinc oxide-Eugenol with aloevera, Calcium hydroxide and sterile water, Calcium hydroxide with sterile water and aloevera, Calcium hydroxide and Iodoform (Metapex) and Vaseline (Control). MIC and MBC of aloevera was calculated. All materials except Vaseline showed varied antimicrobial activity against the test bacterias. The zones of inhibition were ranked into 4 inhibition categories based on the proportional distribution of the data. All the 18 bacterial isolates were classified under 2 groups based on Gram positive and Gram negative aerobes. Statistical analysis was carried out to compare the antimicrobial effectiveness between materials tested with each of the bacterial groupings. Aloevera + Sterile Water was found to have superior antimicrobial activity against most of the microorganisms followed by ZOE + Aloevera, calcium hydroxide + Aloevera, ZOE, calcium hydroxide, Metapex in the descending order and Vaseline showed no inhibition.

Comparison of intracanal EndoSequence Root Repair Material and ProRoot MTA to induce pH changes in simulated root resorption defects over 4 weeks in matched pairs of human teeth.

PubMed

Hansen, Stephen W; Marshall, J Gordon; Sedgley, Christine M

2011-04-01

Intracanal mineral trioxide aggregate (MTA) may provide an alternative to calcium hydroxide in the treatment of external inflammatory root resorption. This in vitro study using human matched pairs of teeth compared white ProRoot MTA (WMTA; (Dentsply Tulsa Dental Specialties, Tulsa, OK) and an alternative material with purportedly improved handling properties, EndoSequence Root Repair Material (ES; Brasseler USA, Savannah, GA), by measuring pH in simulated root surface resorptive defects after intracanal placement. The null hypothesis tested was that there is no difference between WMTA and ES. Bilaterally matched pairs (n = 24) of extracted, human, single-rooted teeth were instrumented to apical size 50/.06, and root surface cavities were prepared at 5 mm and 2 mm from the apex. Root canals of experimental matched pairs (n = 20) were filled with WMTA or ES; control pairs (n = 4) were filled with calcium hydroxide (positive control [POS]) or saline (negative control [NEG]). Teeth were sealed coronally and apically and immersed in saline. The pH in root surface cavities was measured at 20 minutes, 3 hours, 24 hours, 1 week, 2 weeks, 3 weeks, and 4 weeks. The pH at 5 mm when compared with the 2-mm level was significantly higher for the WMTA, ES, and POS groups (P < .05, paired t tests); therefore, each level was analyzed separately. At both the 2-mm and 5-mm levels, significant pH changes occurred over time in the WMTA, ES (both P < .0001, repeated-measures analysis of variance), and POS (P < .0001, Friedman test) groups and not in the NEG group (mean pH = 7.32 ± 0.04, P > .05). There were no differences between WMTA and ES at 20 minutes and 3 hours at both levels or at 24 hours at 5mm. The pH of WMTA was higher than ES by 24 hours at the 2-mm level (8.79 vs 8.56, P < .05, paired t test) and after 1 week at the 5-mm level (8.91 vs 8.05, P < .0001) and was thereafter always significantly higher in WMTA compared with ES (P < .0001). The null hypothesis was rejected. In matched pairs of teeth, intracanal placement of WMTA compared with ES resulted in a higher pH in simulated root resorption defects that was time and root level dependent. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Micro-CT analyses of apical enlargement and molar root canal complexity.

PubMed

Markvart, M; Darvann, T A; Larsen, P; Dalstra, M; Kreiborg, S; Bjørndal, L

2012-03-01

To compare the effectiveness of two rotary hybrid instrumentation techniques with focus on apical enlargement in molar teeth and to quantify and visualize spatial details of instrumentation efficacy in root canals of different complexity. Maxillary and mandibular molar teeth were scanned using X-ray microcomputed tomography. Root canals were prepared using either a GT/Profile protocol or a RaCe/NiTi protocol. Variables used for evaluation were the following: distance between root canal surfaces before and after preparation (distance after preparation, DAP), percentage of root canal area remaining unprepared and increase in canal volume after preparation. Root canals were classified according to size and complexity, and consequences of unprepared portions of narrow root canals and intraradicular connections/isthmuses were included in the analyses. One- and two-way anova were used in the statistical analyses. No difference was found between the two techniques: DAP(apical-third) (P = 0.590), area unprepared(apical-third) (P = 0.126) and volume increase(apical-third) (P = 0.821). Unprepared root canal area became larger in relation to root canal size and complexity, irrespective of the technique used. Percentage of root canal area remaining unprepared was significantly lower in small root canals and complex systems compared to large root canals. The isthmus area per se contributed with a mean of 17.6%, and with a mean of 25.7%, when a narrow root canal remained unprepared. The addition of isthmuses did not significantly alter the ratio of instrumented to unprepared areas at total root canal level. Distal and palatal root canals had the highest level of unprepared area irrespective of the two instrumentation techniques examined. © 2011 International Endodontic Journal.

Coronal leakage of four intracanal medications after exposure to human saliva in the presence of a temporary filling material.

PubMed

Verissimo, Rebeca Dibe; Gurgel-Filho, Eduardo Diogo; De-Deus, Gustavo; Coutinho-Filho, Tauby; de Souza-Filho, Francisco Jose

2010-01-01

To determine the time required for the recontamination of root canals medicated with four different materials. A total of 60 intact, caries-free, human single-rooted teeth with straight roots were selected for this study. After chemo-mechanical preparation they must be changed in the specimens into seven groups: 10 teeth medicated with calcium hydroxide (Ca(OH) 2) + Camphorated paramonochlorophanol (CPMC) (G.1); 10 medicated with 2.5% Sodium hypochlorite (NaOCL) (G.2); 10 medicated with 2% Chlorhexidine gluconate (CHX) in gel (G.3); 10 medicated with 2% CHX in gel + Ca(OH) 2 (G.4); 10 without intracanal medicament and sealed with a coronal temporary filling (G.5). Five teeth were without intracanal medicament and coronally unsealed, used as the positive control group (PC) (G.6) and 5 teeth with intact crowns used as the negative control group (NC) (G.7). Glass vials with rubber stoppers were adjusted for use. The medicaments were prepared and injected into the root canals using sterile plastic syringes. An apparatus was used to evaluate for 30 days leakage. The chamber was filled with 3 ml of human saliva and Brain Heart Infusion (BHI) broth, incubated at 37 degrees C and checked daily for the appearance of turbidity in the BHI broth. Recontamination was detected after an average time of 2.6 days in group 2, 15.9 days in group 3, 30 days in group 1, 27.6 days in group 4, 2.9 days in group 5, 1 day in the positive control, and there was no contamination in the negative control group. The NaOCl group showed the highest worst average of recontamination; on the other hand, high averages were also shown by Ca(OH) 2 + CPMC and Ca(OH) 2 + 2% CHX in gel.

Zinc allocation and re-allocation in rice.

PubMed

Stomph, Tjeerd Jan; Jiang, Wen; Van Der Putten, Peter E L; Struik, Paul C

2014-01-01

Agronomy and breeding actively search for options to enhance cereal grain Zn density. Quantifying internal (re-)allocation of Zn as affected by soil and crop management or genotype is crucial. We present experiments supporting the development of a conceptual model of whole plant Zn allocation and re-allocation in rice. Two solution culture experiments using (70)Zn applications at different times during crop development and an experiment on within-grain distribution of Zn are reported. In addition, results from two earlier published experiments are re-analyzed and re-interpreted. A budget analysis showed that plant zinc accumulation during grain filling was larger than zinc allocation to the grains. Isotope data showed that zinc taken up during grain filling was only partly transported directly to the grains and partly allocated to the leaves. Zinc taken up during grain filling and allocated to the leaves replaced zinc re-allocated from leaves to grains. Within the grains, no major transport barrier was observed between vascular tissue and endosperm. At low tissue Zn concentrations, rice plants maintained concentrations of about 20 mg Zn kg(-1) dry matter in leaf blades and reproductive tissues, but let Zn concentrations in stems, sheath, and roots drop below this level. When plant zinc concentrations increased, Zn levels in leaf blades and reproductive tissues only showed a moderate increase while Zn levels in stems, roots, and sheaths increased much more and in that order. In rice, the major barrier to enhanced zinc allocation towards grains is between stem and reproductive tissues. Enhancing root to shoot transfer will not contribute proportionally to grain zinc enhancement.

Incidence of apical crack formation and propagation during removal of root canal filling materials with different engine driven nickel-titanium instruments.

PubMed

Özyürek, Taha; Tek, Vildan; Yılmaz, Koray; Uslu, Gülşah

2017-11-01

To determine the incidence of crack formation and propagation in apical root dentin after retreatment procedures performed using ProTaper Universal Retreatment (PTR), Mtwo-R, ProTaper Next (PTN), and Twisted File Adaptive (TFA) systems. The study consisted of 120 extracted mandibular premolars. One millimeter from the apex of each tooth was ground perpendicular to the long axis of the tooth, and the apical surface was polished. Twenty teeth served as the negative control group. One hundred teeth were prepared, obturated, and then divided into 5 retreatment groups. The retreatment procedures were performed using the following files: PTR, Mtwo-R, PTN, TFA, and hand files. After filling material removal, apical enlargement was done using apical size 0.50 mm ProTaper Universal (PTU), Mtwo, PTN, TFA, and hand files. Digital images of the apical root surfaces were recorded before preparation, after preparation, after obturation, after filling removal, and after apical enlargement using a stereomicroscope. The images were then inspected for the presence of new apical cracks and crack propagation. Data were analyzed with χ 2 tests using SPSS 21.0 software. New cracks and crack propagation occurred in all the experimental groups during the retreatment process. Nickel-titanium rotary file systems caused significantly more apical crack formation and propagation than the hand files. The PTU system caused significantly more apical cracks than the other groups after the apical enlargement stage. This study showed that retreatment procedures and apical enlargement after the use of retreatment files can cause crack formation and propagation in apical dentin.

Zinc allocation and re-allocation in rice

PubMed Central

Stomph, Tjeerd Jan; Jiang, Wen; Van Der Putten, Peter E. L.; Struik, Paul C.

2014-01-01

Aims: Agronomy and breeding actively search for options to enhance cereal grain Zn density. Quantifying internal (re-)allocation of Zn as affected by soil and crop management or genotype is crucial. We present experiments supporting the development of a conceptual model of whole plant Zn allocation and re-allocation in rice. Methods: Two solution culture experiments using 70Zn applications at different times during crop development and an experiment on within-grain distribution of Zn are reported. In addition, results from two earlier published experiments are re-analyzed and re-interpreted. Results: A budget analysis showed that plant zinc accumulation during grain filling was larger than zinc allocation to the grains. Isotope data showed that zinc taken up during grain filling was only partly transported directly to the grains and partly allocated to the leaves. Zinc taken up during grain filling and allocated to the leaves replaced zinc re-allocated from leaves to grains. Within the grains, no major transport barrier was observed between vascular tissue and endosperm. At low tissue Zn concentrations, rice plants maintained concentrations of about 20 mg Zn kg−1 dry matter in leaf blades and reproductive tissues, but let Zn concentrations in stems, sheath, and roots drop below this level. When plant zinc concentrations increased, Zn levels in leaf blades and reproductive tissues only showed a moderate increase while Zn levels in stems, roots, and sheaths increased much more and in that order. Conclusions: In rice, the major barrier to enhanced zinc allocation towards grains is between stem and reproductive tissues. Enhancing root to shoot transfer will not contribute proportionally to grain zinc enhancement. PMID:24478788

Estimating Starch Content in Roots of Deciduous Trees--A Visual Technique

Treesearch

Philip M. Wargo; Philip M. Wargo

1975-01-01

A visual technique for determining starch content in roots of forest trees, based onz iodine-staining of starch granules, was compared with a chemical method. Although the chemical method was more precise, roots could be sorted with the visual method into groups that are probably biologically important. The visual technique is simple and can be adapted for use in the...

A technique for locating function roots and for satisfying equality constraints in optimization

NASA Technical Reports Server (NTRS)

Sobieszczanski-Sobieski, Jaroslaw

1991-01-01

A new technique for locating simultaneous roots of a set of functions is described. The technique is based on the property of the Kreisselmeier-Steinhauser function which descends to a minimum at each root location. It is shown that the ensuing algorithm may be merged into any nonlinear programming method for solving optimization problems with equality constraints.

A technique for locating function roots and for satisfying equality constraints in optimization

NASA Technical Reports Server (NTRS)

Sobieszczanski-Sobieski, J.

1992-01-01

A new technique for locating simultaneous roots of a set of functions is described. The technique is based on the property of the Kreisselmeier-Steinhauser function which descends to a minimum at each root location. It is shown that the ensuing algorithm may be merged into any nonlinear programming method for solving optimization problems with equality constraints.

A global Fine-Root Ecology Database to address below-ground challenges in plant ecology.

PubMed

Iversen, Colleen M; McCormack, M Luke; Powell, A Shafer; Blackwood, Christopher B; Freschet, Grégoire T; Kattge, Jens; Roumet, Catherine; Stover, Daniel B; Soudzilovskaia, Nadejda A; Valverde-Barrantes, Oscar J; van Bodegom, Peter M; Violle, Cyrille

2017-07-01

Variation and tradeoffs within and among plant traits are increasingly being harnessed by empiricists and modelers to understand and predict ecosystem processes under changing environmental conditions. While fine roots play an important role in ecosystem functioning, fine-root traits are underrepresented in global trait databases. This has hindered efforts to analyze fine-root trait variation and link it with plant function and environmental conditions at a global scale. This Viewpoint addresses the need for a centralized fine-root trait database, and introduces the Fine-Root Ecology Database (FRED, http://roots.ornl.gov) which so far includes > 70 000 observations encompassing a broad range of root traits and also includes associated environmental data. FRED represents a critical step toward improving our understanding of below-ground plant ecology. For example, FRED facilitates the quantification of variation in fine-root traits across root orders, species, biomes, and environmental gradients while also providing a platform for assessments of covariation among root, leaf, and wood traits, the role of fine roots in ecosystem functioning, and the representation of fine roots in terrestrial biosphere models. Continued input of observations into FRED to fill gaps in trait coverage will improve our understanding of changes in fine-root traits across space and time. © 2017 UT-Battelle LLC. New Phytologist © 2017 New Phytologist Trust.

Effect of zoledronic acid used in the root surface treatment of late replanted teeth: a study in rats.

PubMed

Mori, Graziela Garrido; Janjacomo, Daniela Maria de Mendonça; Nunes, Daniele Clapes; Castilho, Lithiene Ribeiro

2010-01-01

This study evaluated the use of zoledronic acid, a resorption inhibitor, as a medication for root resorption treatment of late replanted teeth. Twenty-four maxillary right central incisors of rats were avulsed and kept dry for 30 min. Then, the teeth were divided into 2 groups. In group I, root surface was treated with 2% sodium fluoride for 20 min; in group II, 10-6M zoledronic acid solution was used for 20 min. All root canals were filled with calcium hydroxide. Next, teeth were replanted in their respective sockets. After 15 and 60 days post-replantation, the animals were killed and the anatomic pieces were obtained and prepared for microscopic and morphometric analyses. The results showed that zoledronic acid was capable of limiting the occurrence of root resorption and preserving cementum resorption. Further research must be performed to confirm the use of zoledronic acid in root surface treatment of late replanted teeth.

30 CFR 717.17 - Protection of the hydrologic system.

Code of Federal Regulations, 2012 CFR

2012-07-01

... be free of sod, large roots, other large vegetative matter, and frozen soil, and in no case shall... lowest point of the foundation. The fill shall be brought up in horizontal layers of such thickness as is...

30 CFR 717.17 - Protection of the hydrologic system.

Code of Federal Regulations, 2013 CFR

2013-07-01

... be free of sod, large roots, other large vegetative matter, and frozen soil, and in no case shall... lowest point of the foundation. The fill shall be brought up in horizontal layers of such thickness as is...

30 CFR 717.17 - Protection of the hydrologic system.

Code of Federal Regulations, 2014 CFR

2014-07-01

... be free of sod, large roots, other large vegetative matter, and frozen soil, and in no case shall... lowest point of the foundation. The fill shall be brought up in horizontal layers of such thickness as is...

Test evaluation of a laminated wood wind turbine blade concept

NASA Technical Reports Server (NTRS)

Faddoul, J. R.

1981-01-01

A series of tests conducted on a root end section of a laminated wood wind turbine blade are reported. The blade to hub transition of the wood blade uses steel studs cast into the wood D spar with a filled epoxy. Both individual studs and a full scale, short length, root section were tested. Results indicate that the bonded stud concept is more than adequate for both the 30 year life fatigue loads and for the high wind or hurricane gust loads.

The Mt. Gilead Cemetery Study: An Example of Biocultural Analysis from Western Georgia.

DTIC Science & Technology

1986-02-01

recognize against the lighter matrix at about 1.0 - 1.2 m below the original ground surface. At this point, the pans were dis- missed and the field crew...general soil matrix outside the grave fill. Detailed photographs of certain skeletal elements which exhibited pathologies were taken (color slides...and sharp. Of the molars, the roots of #3, #19, and #32 remained; #14 was in place but was 39 -.. hollowed halfway down the buccal roots by gingival

Aesthetic management of gingival recession by root biomodification with carbon dioxide laser and subepithelial connective tissue graft with lateral repositioned flap technique

PubMed Central

Rastogi, Pavitra Kumar; Lal, Nand; Garg, Nimit; Anand, Vishal; Singhal, Rameshwari

2012-01-01

Localised gingival recessions continue to represent an important aesthetic condition requiring treatment in periodontics. Various techniques have been tried to treat exposed root surfaces to improve aesthetics with high percentage of success and minimal discomfort. Root biomodification is done to improve the predictability of these procedures. This clinical report describes periodontal plastic procedure involving subepithelial connective tissue graft with lateral repositioned flap technique and root biomodification with CO2 laser for the management of gingival recession. PMID:22778454

Regeneration and Repair in Endodontics—A Special Issue of the Regenerative Endodontics—A New Era in Clinical Endodontics

PubMed Central

Saoud, Tarek Mohamed A.; Ricucci, Domenico; Lin, Louis M.; Gaengler, Peter

2016-01-01

Caries is the most common cause of pulp-periapical disease. When the pulp tissue involved in caries becomes irreversibly inflamed and progresses to necrosis, the treatment option is root canal therapy because the infected or non-infected necrotic pulp tissue in the root canal system is not accessible to the host's innate and adaptive immune defense mechanisms and antimicrobial agents. Therefore, the infected or non-infected necrotic pulp tissue must be removed from the canal space by pulpectomy. As our knowledge in pulp biology advances, the concept of treatment of pulpal and periapical disease also changes. Endodontists have been looking for biologically based treatment procedures, which could promote regeneration or repair of the dentin-pulp complex destroyed by infection or trauma for several decades. After a long, extensive search in in vitro laboratory and in vivo preclinical animal experiments, the dental stem cells capable of regenerating the dentin-pulp complex were discovered. Consequently, the biological concept of ‘regenerative endodontics’ emerged and has highlighted the paradigm shift in the treatment of immature permanent teeth with necrotic pulps in clinical endodontics. Regenerative endodontics is defined as biologically based procedures designed to physiologically replace damaged tooth structures, including dentin and root structures, as well as the pulp-dentin complex. According to the American Association of Endodontists’ Clinical Considerations for a Regenerative Procedure, the primary goal of the regenerative procedure is the elimination of clinical symptoms and the resolution of apical periodontitis. Thickening of canal walls and continued root maturation is the secondary goal. Therefore, the primary goal of regenerative endodontics and traditional non-surgical root canal therapy is the same. The difference between non-surgical root canal therapy and regenerative endodontic therapy is that the disinfected root canals in the former therapy are filled with biocompatible foreign materials and the root canals in the latter therapy are filled with the host's own vital tissue. The purpose of this article is to review the potential of using regenerative endodontic therapy for human immature and mature permanent teeth with necrotic pulps and/or apical periodontitis, teeth with persistent apical periodontitis after root canal therapy, traumatized teeth with external inflammatory root resorption, and avulsed teeth in terms of elimination of clinical symptoms and resolution of apical periodontitis. PMID:29563445

Regeneration and Repair in Endodontics-A Special Issue of the Regenerative Endodontics-A New Era in Clinical Endodontics.

PubMed

Saoud, Tarek Mohamed A; Ricucci, Domenico; Lin, Louis M; Gaengler, Peter

2016-02-27

Caries is the most common cause of pulp-periapical disease. When the pulp tissue involved in caries becomes irreversibly inflamed and progresses to necrosis, the treatment option is root canal therapy because the infected or non-infected necrotic pulp tissue in the root canal system is not accessible to the host's innate and adaptive immune defense mechanisms and antimicrobial agents. Therefore, the infected or non-infected necrotic pulp tissue must be removed from the canal space by pulpectomy. As our knowledge in pulp biology advances, the concept of treatment of pulpal and periapical disease also changes. Endodontists have been looking for biologically based treatment procedures, which could promote regeneration or repair of the dentin-pulp complex destroyed by infection or trauma for several decades. After a long, extensive search in in vitro laboratory and in vivo preclinical animal experiments, the dental stem cells capable of regenerating the dentin-pulp complex were discovered. Consequently, the biological concept of 'regenerative endodontics' emerged and has highlighted the paradigm shift in the treatment of immature permanent teeth with necrotic pulps in clinical endodontics. Regenerative endodontics is defined as biologically based procedures designed to physiologically replace damaged tooth structures, including dentin and root structures, as well as the pulp-dentin complex. According to the American Association of Endodontists' Clinical Considerations for a Regenerative Procedure, the primary goal of the regenerative procedure is the elimination of clinical symptoms and the resolution of apical periodontitis. Thickening of canal walls and continued root maturation is the secondary goal. Therefore, the primary goal of regenerative endodontics and traditional non-surgical root canal therapy is the same. The difference between non-surgical root canal therapy and regenerative endodontic therapy is that the disinfected root canals in the former therapy are filled with biocompatible foreign materials and the root canals in the latter therapy are filled with the host's own vital tissue. The purpose of this article is to review the potential of using regenerative endodontic therapy for human immature and mature permanent teeth with necrotic pulps and/or apical periodontitis, teeth with persistent apical periodontitis after root canal therapy, traumatized teeth with external inflammatory root resorption, and avulsed teeth in terms of elimination of clinical symptoms and resolution of apical periodontitis.

Postoperative quality of life following single-visit root canal treatment performed by rotary or reciprocating instrumentation: a randomized clinical trial.

PubMed

Pasqualini, D; Corbella, S; Alovisi, M; Taschieri, S; Del Fabbro, M; Migliaretti, G; Carpegna, G C; Scotti, N; Berutti, E

2016-11-01

To compare the impact of rotary and reciprocating instrumentation on postoperative quality of life (POQoL) after single-visit primary root canal treatment. A randomized controlled clinical trial was designed and carried out in a University endodontic practice in northern Italy. Healthy subjects with asymptomatic irreversible pulpitis, symptomatic irreversible pulpitis or pulp necrosis with or without apical periodontitis (symptomatic or asymptomatic) scheduled for primary root canal treatment were enrolled. Single-visit root canal treatment was performed with ProTaper ™ S1-S2-F1-F2 (rotary group, n = 23) and WaveOne ™ Primary (reciprocating group, n = 24). Irrigation was performed with 5% NaOCl and 10% EDTA. Root canal filling was performed with the continuous-wave technique and ZOE sealer. POQoL indicators were evaluated for 7 days post-treatment. The variation of each indicator over time was compared using anova for repeated measures (P < 0.05). The impact of each variable on POQoL was analysed with a multivariate logistic regression model (P < 0.05). Pain curves demonstrated a more favourable time-trend in the rotary group (mean, P = 0.077; maximum, P = 0.015). Difficulty in eating (P = 0.017), in performing daily activities (P = 0.023), in sleeping (P = 0.021) and in social relations (P = 0.077), was more evident in the reciprocating group. Patients' perception of the impact of treatment on POQoL was more favourable in the rotary group (P = 0.006). Multirooted tooth type and pre-existing periradicular inflammation were associated with a decrease in POQoL. Reciprocating instrumentation affected POQoL to a greater extent than rotary instrumentation. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

An In vitro Comparison and Evaluation of Sealing Ability of Newly Introduced C-point System, Cold Lateral Condensation, and Thermoplasticized Gutta-Percha Obturating Technique: A Dye Extraction Study.

PubMed

Sinhal, Tapati Manohar; Shah, Ruchi Rani Purvesh; Jais, Pratik Subhas; Shah, Nimisha Chinmay; Hadwani, Krupali Dhirubhai; Rothe, Tushar; Sinhal, Neha Nilesh

2018-01-01

The aim of this study is to compare and to evaluate sealing ability of newly introduced C-point system, cold lateral condensation, and thermoplasticized gutta-percha obturating technique using a dye extraction method. Sixty extracted maxillary central incisors were decoronated below the cementoenamel junction. Working length was established, and biomechanical preparation was done using K3 rotary files with standard irrigation protocol. Teeth were divided into three groups according to the obturation protocol; Group I-Cold lateral condensation, Group II-Thermoplasticized gutta-percha, and Group III-C-Point obturating system. After obturation all samples were subjected to microleakage assessment using dye extraction method. Obtained scores will be statistical analyzed using ANOVA test and post hoc Tukey's test. One-way analysis of variance revealed that there is significant difference among the three groups with P value (0.000 < 0.05). Tukey's HSD post hoc tests for multiple comparisons test shows that the Group II and III perform significantly better than Group I. Group III performs better than Group II with no significant difference. All the obturating technique showed some degree of microleakage. Root canals filled with C-point system showed least microleakage followed by thermoplasticized obturating technique with no significant difference among them. C-point obturation system could be an alternative to the cold lateral condensation technique.

Defective secretion of mucilage is the cellular basis for agravitropism in primary roots of Zea mays cv. Ageotropic

NASA Technical Reports Server (NTRS)

Miller, I.; Moore, R.

1990-01-01

Root caps of primary, secondary, and seminal roots of Z. mays cv. Kys secrete large amounts of mucilage and are in close contact with the root all along the root apex. These roots are strongly graviresponsive. Secondary and seminal roots of Z. mays cv. Ageotropic are also strongly graviresponsive. Similarly, their caps secrete mucilage and closely appress the root all along the root apex. However, primary roots of Z. mays cv. Ageotropic are non-responsive to gravity. Their caps secrete negligible amounts of mucilage and contact the root only at the extreme apex of the root along the calyptrogen. These roots become graviresponsive when their tips are coated with mucilage or mucilage-like materials. Peripheral cells of root caps of roots of Z. mays cv. Kys contain many dictyosomes associated with vesicles that migrate to and fuse with the plasmalemma. Root-cap cells of secondary and seminal (i.e. graviresponsive) roots of Z. mays cv. Ageotropic are similar to those of primary roots of Z. mays cv. Kys. However, root-cap cells of primary (i.e. non-graviresponsive) roots of Z. mays cv. Ageotropic have distended dictyosomal cisternae filled with an electron-dense, granular material. Large vesicles full of this material populate the cells and apparently do not fuse with the plasmalemma. Taken together, these results suggest that non-graviresponsiveness of primary roots of Z. mays cv. Ageotropic results from the lack of apoplastic continuity between the root and the periphery of the root cap. This is a result of negligible secretion of mucilage by cells along the edge of the root cap which, in turn, appears to be due to the malfunctioning of dictyosomes in these cells.

Augmentation of the Pullout Repair of a Medial Meniscus Posterior Root Tear by Arthroscopic Centralization.

PubMed

Koga, Hideyuki; Watanabe, Toshifumi; Horie, Masafumi; Katagiri, Hiroki; Otabe, Koji; Ohara, Toshiyuki; Katakura, Mai; Sekiya, Ichiro; Muneta, Takeshi

2017-08-01

The meniscus roots are critical for meniscus function in preserving correct knee kinematics and avoiding meniscus extrusion and, consequently, in the progression of osteoarthritis. Several techniques exist for medial meniscus posterior root tear repair; however, current surgical techniques have been proved to fail to reduce meniscus extrusion, which has been shown to be associated with development of osteoarthritis, although significant improvements in the postoperative clinical findings have been achieved. This Technical Note describes an arthroscopic technique for the medial meniscus posterior root tear in which a pullout repair is augmented by a centralization technique to restore and maintain the medial meniscus function by efficiently reducing meniscus extrusion.

Species richness and selenium accumulation of plants in soils with elevated concentration of selenium and salinity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Z.Z.; Wu, L.

1991-12-01

Field studies were conducted in soils with elevated concentrations of Se and salinity at Kesterson, California. Biomass distribution, species richness, and selenium accumulation of plants were examined for two sites where 15 cm of surface soil was removed and replaced with fill dirt in the fall of 1989, and two sites were native soil cover. The Se concentrations in the top 15 cm of fill dirt ranged from undetectable to 36 ng g-1. For the native soil sites, Se levels ranged from 75 to 550 ng g-1. Soil Se concentrations below 15 cm ranged from 300 to 700 ng g-1more » and were comparable between the fill dirt and the native soil sites. At least 20 different plant species were brought into the two fill dirt sites with the top soil. Avena fatua L., Bassia hyssopifolia Kuntze Rev. Gen. Pl., Centaurea solstitialis L., Erysimum officianale L., Franseria acanthicarpa Cav. Icon., and Melilotus indica (L.) All. contributed over 60% of the total biomass. Only 5 species were found in the native soil sites, and salt grass (Distichlis spicata L.) was the predominant species and accounted for over 80% of the total biomass. Between 1989 and 1990, two years after the surface soil replacement, the two fill dirt sites had a 70% reduction in species richness. Plant tissue selenium concentrations were found to be quite variable between plant species and between sites of sampling. At the fill dirt sites, the plant species with deep root systems accumulated greater amounts of selenium than the shallow-rooted species. The soil selenium concentration of the field soil had no negative effect on pollen fertility, seed set, and seed germination for the plant species examined. However, seedling growth was impaired by the soil selenium concentrations. This suggests that a selection pressure of soil Se concentration may have been imposed on plant species such as M. indica in an early stage of its life cycle.« less

Ligament, nerve, and blood vessel anatomy of the lateral zone of the lumbar intervertebral foramina.

PubMed

Yuan, Shi-Guo; Wen, You-Liang; Zhang, Pei; Li, Yi-Kai

2015-11-01

To provide an anatomical basis for intrusive treatment using an approach through the lateral zones of the lumbar intervertebral foramina (LIF), especially for acupotomology lysis, percutaneous transforaminal endoscopy, and lumbar nerve root block. Blood vessels, ligaments, nerves, and adjacent structures of ten cadavers were exposed through the L1-2 to L5-S1 intervertebral foramina and examined. The lateral zones of the LIF were almost filled by ligaments, nerves, and blood vessels, which were separated into compartments by superior/inferior transforaminal ligaments and corporotransverse superior/inferior ligaments. Two zones relatively lacking in blood vessels and nerves (triangular working zones) were found beside the lamina of the vertebral arch and on the root of the transverse processus. Both the ascending lumbar vein and branches of the intervetebral vein were observed in 12 Kambin's triangles, and in only seven Kambin's triangles were without any veins. Nerves and blood vessels are fixed and protected by transforaminal ligaments and/or corporotransverse ligaments. It is necessary to distinguish the ligaments from nerves using transforaminal endoscopy so that the ligaments can be cut without damaging nerves. Care needs to be taken in intrusive operations because of the veins running through Kambin's triangle. We recommend injecting into the lamina of the vertebral arch and the midpoint between the adjacent roots of the transverse processus when administering nerve root block. Blind percutaneous incision and acupotomology lysis is dangerous in the lateral zones of the LIF, as they are filled with nerves and blood vessels.

Vegetation effects on event water dynamics - Insights from in-situ stable isotope observations and dye patterns

NASA Astrophysics Data System (ADS)

Volkmann, Till; Haberer, Kristine; Gessler, Arthur; Weiler, Markus

2014-05-01

The predicted changes of climate and land-use could have drastic effects on the water balance of ecosystems, particularly under frequent drought and subsequent rewetting conditions. Yet, inference of these effects and related consequences for the structure and functioning of ecosystems, groundwater recharge, leaching of nutrients and pollutants, drinking water availability, and the water cycle is currently impeded by gaps in our understanding of the manifold interactions between vegetation and soil water dynamics. While plants require water and nutrients, they also exert, for instance, important below-ground controls on the distribution and movement of water and chemicals in the rooted soil horizons via uptake and redistribution of water, modification of soil hydraulic properties, and formation of conduits for rapid preferential water flow. This work aims to contribute to fill existing gaps by assessing the effects of different plant types and their rooting systems on the soil water dynamics. Therefore, we conducted artificial drought and subsequent rewetting experiments using isotopically and dye (Brilliant Blue FCF) labeled water on plots of various surface cover (bare soil, grass, beech, oak, vine) established on relatively homogeneous luvisol on loess in southwestern Germany. Detailed insight into the short-term dynamics of event water infiltration and root uptake during the field experiments was facilitated by the application of novel techniques for high-frequency in-situ monitoring of stable isotope signatures in pore and transpiration water using commercial laser-based spectrometers, augmenting conventional observations of soil physicochemical states (soil water content, matric potential, electrical conductivity). The temporal point information is complemented by dye staining profiles, providing a detailed picture of spatial infiltration patterns, and by root density observations. The results of the experiments allow for a comprehensive spatiotemporal characterization of the effects of differing vegetation cover and rooting systems on infiltration, preferential flow path characteristics, and water storage in the rooted soil horizons. This will contribute to an improved ability to estimate environmental change impacts on the fate of water, nutrients, and pollutants in this critical zone and associated feedbacks within the soil-vegetation-atmosphere system.

Root resistance to cavitation is accurately measured using a centrifuge technique.

PubMed

Pratt, R B; MacKinnon, E D; Venturas, M D; Crous, C J; Jacobsen, A L

2015-02-01

Plants transport water under negative pressure and this makes their xylem vulnerable to cavitation. Among plant organs, root xylem is often highly vulnerable to cavitation due to water stress. The use of centrifuge methods to study organs, such as roots, that have long vessels are hypothesized to produce erroneous estimates of cavitation resistance due to the presence of open vessels through measured samples. The assumption that roots have long vessels may be premature since data for root vessel length are sparse; moreover, recent studies have not supported the existence of a long-vessel artifact for stems when a standard centrifuge technique was used. We examined resistance to cavitation estimated using a standard centrifuge technique and compared these values with native embolism measurements for roots of seven woody species grown in a common garden. For one species we also measured vulnerability using single-vessel air injection. We found excellent agreement between root native embolism and the levels of embolism measured using a centrifuge technique, and with air-seeding estimates from single-vessel injection. Estimates of cavitation resistance measured from centrifuge curves were biologically meaningful and were correlated with field minimum water potentials, vessel diameter (VD), maximum xylem-specific conductivity (Ksmax) and vessel length. Roots did not have unusually long vessels compared with stems; moreover, root vessel length was not correlated to VD or to the vessel length of stems. These results suggest that root cavitation resistance can be accurately and efficiently measured using a standard centrifuge method and that roots are highly vulnerable to cavitation. The role of root cavitation resistance in determining drought tolerance of woody species deserves further study, particularly in the context of climate change. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Grout compactness monitoring of concrete-filled fiber-reinforced polymer tube using electromechanical impedance

NASA Astrophysics Data System (ADS)

Shi, Yaokun; Luo, Mingzhang; Li, Weijie; Song, Gangbing

2018-05-01

The concrete-filled fiber-reinforced polymer tube (CFFT) is a type of structural element widely used in corrosive environments. Poor grout compactness results in incomplete contact or even no contact between the fiber-reinforced polymer (FRP) tube and the concrete grout, which reduces the load bearing capacity of a CFFT. The monitoring of grout compactness for CFFTs is important. The piezoceramic-based electromechanical impedance (EMI) method has emerged as an efficient and low-cost structural health monitoring technique. This paper presents a feasibility study using the EMI method to monitor grout compactness of CFFTs. In this research, CFFT specimens with different levels of compactness (empty, 1/5, 1/3, 1/2, 2/3, and full compactness) were prepared and subjected to EMI measurement by using four piezoceramic patches that were bonded circumferentially along the outer surface of the CFFT. To analyze the correlation between grout compactness and EMI signatures, a compactness index (CI) was proposed based on the root-mean-square deviation (RMSD). The experimental results show that the changes in admittance signatures are able to determine the grout compactness qualitatively. The proposed CI is able to effectively identify the compactness of the CFFT, and provides location information of the incomplete concrete infill.

Influence of ultrasonic and sonic activation of epoxy-amine resin-based sealer on penetration of sealer into lateral canals.

PubMed

Arslan, Hakan; Abbas, Aneesh; Karatas, Ertugrul

2016-11-01

The aim of this study was to evaluate the efficacy of sonic and ultrasonic activation of epoxy-amine resin-based root canal sealer (2Seal; VDW GmbH, München, Germany) on penetration of the sealer into lateral canals compared to non-activated filling. Thirty-six single-rooted human anterior teeth were decoronated and prepared, using the ProTaper rotary system (Dentsply Maillefer, Ballaigues, Switzerland) to F4. After the completion of the clearing procedures, lateral canals were created at 2, 4, and 6 mm from the working length. The specimens were randomly divided into a control group (non-activated sealer application) and two experimental groups that received a sealer application with either sonic or ultrasonic activation. The root canals were filled using cold lateral compaction and images were obtained from each lateral canals at 40× magnification using a stereomicroscope. The sealer penetration was evaluated using a four-grade scoring system. The data were evaluated statistically using the Kruskal-Wallis and Mann-Whitney U tests with a 95 % confidence level (P = 0.05). The ultrasonic activation resulted in a better sealer penetration compared with the non-activated and sonically activated groups (P < 0.001). Sonic activation also resulted in better sealer penetration compared to the non-activated group (P < 0.001). The use of the ultrasonic activation of an epoxy-amine resin-based sealer promoted greater sealer penetration into the lateral canals. Sonic activation was not effective as ultrasonic activation, but was more effective than the non-activated group. The ultrasonic activation of an epoxy-amine resin-based sealer could be beneficial in filling procedures.

Fracture resistance of simulated immature teeth filled with Biodentine and white mineral trioxide aggregate - an in vitro study.

PubMed

Elnaghy, Amr M; Elsaka, Shaymaa E

2016-04-01

The purpose of this study was to evaluate the long-term fracture resistance of simulated immature teeth filled with Biodentine (BD) and white mineral trioxide aggregate (WMTA) as pulp space barriers for regenerative endodontic procedures (REPs). Sixty extracted human maxillary anterior teeth were divided into four groups of 15 teeth each. Positive control teeth received no treatment. The remaining teeth were prepared until a size 6 Peeso (1.7 mm) could be passed 1 mm beyond the apex. Then, an engineering twist drill of 3 mm diameter was used to extend the preparation of the canal 3 mm below CEJ. The root canals were irrigated and disinfected according to AAE considerations for REPs. The canals were filled with either BD or WMTA. The negative control canals were left unfilled. The coronal access cavities were restored with glass ionomer followed by composite resin. The teeth were placed in phosphate-buffered saline solution and stored for 12 months. Each specimen was then subjected to fracture testing using a universal testing machine. The peak load to fracture and the fracture resistance were recorded, and the data were analysed statistically. The positive control group had the highest fracture resistance and differed significantly (P < 0.05) from the other experimental groups. No significant difference was found between BD and WMTA (P > 0.05). Considering the risk of cervical root fracture for pulpless infected immature teeth treated with REPs, after 12 months, there was no difference between WMTA and BD regarding the resistance to root fracture. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Discrete square root filtering - A survey of current techniques.

NASA Technical Reports Server (NTRS)

Kaminskii, P. G.; Bryson, A. E., Jr.; Schmidt, S. F.

1971-01-01

Current techniques in square root filtering are surveyed and related by applying a duality association. Four efficient square root implementations are suggested, and compared with three common conventional implementations in terms of computational complexity and precision. It is shown that the square root computational burden should not exceed the conventional by more than 50% in most practical problems. An examination of numerical conditioning predicts that the square root approach can yield twice the effective precision of the conventional filter in ill-conditioned problems. This prediction is verified in two examples.

A clinical evaluation of resorbable hydroxylapatite for the repair of human intra-osseous defects.

PubMed

Corsair, A

1990-01-01

One of the goals of periodontal therapy is actual hard- and soft-tissue regeneration or at least the functional repair of periodontal defects. Alloplastic materials used in the past included dense hydroxylapatite grafts which were non-resorbable and often exfoliated. A new resorbable hydroxylapatite biomaterial [OsteoGen (HA RESORB)] was used during flap surgery. After the usual initial therapy, full-thickness flaps were elevated. A through debridement of the roots and osseous defects was accomplished. The defects were measured and then filled with OsteoGen. The mean initial bone defect depth was 4.47 mm. These defects were re-evaluated by the probing of bone levels after a 4-6-month healing period. A mean of 2.26 mm of new bone fill was obtained. This represents an average fill of 51%. Seventeen of the 22 defects had 42% or more actual new bone fill. No foreign body reaction or exfoliation occurred.

Effect of different intraorifice barriers on the fracture resistance of roots obturated with Resilon or gutta-percha.

PubMed

Nagas, Emre; Uyanik, Ozgur; Altundasar, Emre; Durmaz, Veli; Cehreli, Zafer C; Vallittu, Pekka K; Lassila, Lippo V J

2010-06-01

This study investigated and compared the root reinforcement potential of 3 different intraorifice barriers (mineral trioxide aggregate [MTA], resin-modified glass ionomer cement [Vitremer], and fiber-reinforced composite [FRC]) placed over root canals obturated with gutta-percha or Resilon. Crowns of 80 extracted human mandibular premolars were sectioned off to obtain 14-mm-long root specimens. After preparation of root canals with nickel-titanium rotary files, the roots were obturated with either the Resilon/Epiphany system or gutta-percha + AH Plus sealer. In both obturation groups, specimens were further subgrouped with respect to the intraorifice barrier material placed after removal of 3-mm coronal portion of the root fillings: (1) MTA, (2) Vitremer, and (3) FRC. The specimens were loaded vertically at 1 mm/min crosshead speed until vertical root fracture occurred. Results were evaluated statistically with two-way analysis of variance and Tukey tests. Fracture resistance of roots was significantly affected by the type of intraorifice barrier (P < .05), but not by the type of obturation system used (P > .05). The use of Vitremer and FRC significantly improved the fracture resistance, whereas MTA did not exhibit any reinforcing effect as an intraorifice barrier. Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Defect reduction for semiconductor memory applications using jet and flash imprint lithography

NASA Astrophysics Data System (ADS)

Ye, Zhengmao; Luo, Kang; Irving, J. W.; Lu, Xiaoming; Zhang, Wei; Fletcher, Brian; Liu, Weijun; Xu, Frank; LaBrake, Dwayne; Resnick, Douglas; Sreenivasan, S. V.

2013-03-01

Imprint lithography has been shown to be an effective technique for replication of nano-scale features. Jet and Flash Imprint Lithography (J-FIL) involves the field-by-field deposition and exposure of a low viscosity resist deposited by jetting technology onto the substrate. The patterned mask is lowered into the fluid which then quickly flows into the relief patterns in the mask by capillary action. Following this filling step, the resist is crosslinked under UV radiation, and then the mask is removed leaving a patterned resist on the substrate. Acceptance of imprint lithography for manufacturing will require demonstration that it can attain defect levels commensurate with the defect specifications of high end memory devices. Typical defectivity targets are on the order of 0.10/cm2. In previous studies, we have focused on defects such as random non-fill defects occurring during the resist filling process and repeater defects caused by interactions with particles on the substrate. In this work, we attempted to identify the critical imprint defect types using a mask with NAND Flash-like patterns at dimensions as small as 26nm. The two key defect types identified were line break defects induced by small particulates and airborne contaminants which result in local adhesion failure. After identification, the root cause of the defect was determined, and corrective measures were taken to either eliminate or reduce the defect source. As a result, we have been able to reduce defectivity levels by more than three orders of magnitude in only 12 months and are now achieving defectivity adders as small as 2 adders per lot of wafers.

Analysis of hairy root culture of Rauvolfia serpentina using direct analysis in real time mass spectrometric technique.

PubMed

Madhusudanan, K P; Banerjee, Suchitra; Khanuja, Suman P S; Chattopadhyay, Sunil K

2008-06-01

The applicability of a new mass spectrometric technique, DART (direct analysis in real time) has been studied in the analysis of the hairy root culture of Rauvolfia serpentina. The intact hairy roots were analyzed by holding them in the gap between the DART source and the mass spectrometer for measurements. Two nitrogen-containing compounds, vomilenine and reserpine, were characterized from the analysis of the hairy roots almost instantaneously. The confirmation of the structures of the identified compounds was made through their accurate molecular formula determinations. This is the first report of the application of DART technique for the characterization of compounds that are expressed in the hairy root cultures of Rauvolfia serpentina. Moreover, this also constitutes the first report of expression of reserpine in the hairy root culture of Rauvolfia serpentina. Copyright (c) 2008 John Wiley & Sons, Ltd.

Prosthetic valve sparing aortic root replacement: an improved technique.

PubMed

Leacche, Marzia; Balaguer, Jorge M; Umakanthan, Ramanan; Byrne, John G

2008-10-01

We describe a modified surgical technique to treat patients with a previous history of isolated aortic valve replacement who now require aortic root replacement for an aneurysmal or dissected aorta. This technique consists of replacing the aortic root with a Dacron conduit, leaving intact the previously implanted prosthesis, and re-implanting the coronary arteries in the Dacron graft. Our technique differs from other techniques in that we do not leave behind any aortic tissue remnant and also in that we use a felt strip to obliterate any gap between the old sewing ring and the newly implanted graft. In our opinion, this promotes better hemostasis. We demonstrate that this technique is safe, feasible, and results in acceptable outcomes.

Medial Meniscus Posterior Root Tear Repair Using a 2-Simple-Suture Pullout Technique.

PubMed

Samy, Tarek Mohamed; Nassar, Wael A M; Zakaria, Zeiad Mohamed; Farrag Abdelaziz, Ahmed Khaled

2017-06-01

Medial meniscus posterior root tear is one of the underestimated knee injuries in terms of incidence. Despite its grave sequelae, using simple but effective technique can maintain the native knee joint longevity. In the current note, a 2-simple-suture pullout technique was used to effectively reduce the meniscus posterior root to its anatomic position. The success of the technique depended on proper tool selection as well as tibial tunnel direction that allowed easier root suturing and better suture tensioning, without inducing any iatrogenic articular cartilage injury or meniscal tissue loss. Using anterior knee arthroscopy portals, anterolateral as a viewing portal and anteromedial as a working portal, a 7-mm tibial tunnel starting at Gerdy tubercle and ending at the medial meniscus posterior root bed was created. The 2 simple sutures were retrieved through the tunnel and tensioned and secured over a 12-mm-diameter washer at the tibial tunnel outer orifice. Anatomic reduction of the medial meniscus posterior root tear was confirmed arthroscopically intraoperatively and radiologically by postoperative magnetic resonance imaging.

Collagen membranes: a review.

PubMed

Bunyaratavej, P; Wang, H L

2001-02-01

Collagen materials have been utilized in medicine and dentistry because of their proven biocompatability and capability of promoting wound healing. For guided tissue regeneration (GTR) procedures, collagen membranes have been shown to be comparable to non-absorbable membranes with regard to probing depth reduction, clinical attachment gain, and percent of bone fill. Although these membranes are absorbable, collagen membranes have been demonstrated to prevent epithelial down-growth along the root surfaces during the early phase of wound healing. The use of grafting material in combination with collagen membranes seems to improve clinical outcomes for furcation, but not intrabony, defects when compared to the use of membranes alone. Recently, collagen materials have also been applied in guided bone regeneration (GBR) and root coverage procedures with comparable success rates to non-absorbable expanded polytetrafluoroethylene (ePTFE) membranes and conventional subepithelial connective tissue grafts, respectively. Long-term clinical trials are still needed to further evaluate the benefits of collagen membranes in periodontal and peri-implant defects. This article will review the rationale for each indication and its related literature, both in vitro and in vivo studies. The properties that make collagen membranes attractive for use in regenerative therapy will be addressed. In addition, varieties of cross-linking techniques utilized to retard the degradation rate of collagen membranes will be discussed.

[Behavior of different strains of Staphylococcus aureus against root canal filling cements].

PubMed

Pumarola, J; Berástegui, E; Canalda, C; Brau, E

1991-01-01

The mean goal of this study is the determination of the conduct of 120 strains of Staphylococcus aureus against seven root canal sealers: Traitement Spad, Endométhasone, N2 Universal, AH26 with silver, Diaket-A, Tubli Seal and Sealapex. The agar diffusion test was employed in the determination of its bacterial growth inhibition. The results obtained have demonstrated values very different between the tested strains. Therefore we recommended to employ strains with reference in the investigation of the bacterial growth inhibition in order to repeat equal experimentation conditions.

Analysis of the Potential for Plant Uptake of Trichloroethylene and an Assessment of the Relative Risk from Different Crop Types

DTIC Science & Technology

1994-07-01

atmosphere. The chemical solute is absorbed with water from soil solution into the 8 epidermis which contains the "apparent free space" of the root tissue...cortex cells of the root. It accounts for most of the water and solute movement from the soil solution to the endodermis (Lindstrom et al., 1991:130...gas. In general, the higher the vapor pressure, the more likely a chemical will volatilize from the soil solution to air-filled soil pores and/or the

Integration of different data gap filling techniques to facilitate assessment of polychlorinated biphenyls: A proof of principle case study (ASCCT meeting)

EPA Science Inventory

Data gap filling techniques are commonly used to predict hazard in the absence of empirical data. The most established techniques are read-across, trend analysis and quantitative structure-activity relationships (QSARs). Toxic equivalency factors (TEFs) are less frequently used d...

Endodontic decision making for asymptomatic root-filled teeth with apical periodontitis - A radiographic survey.

PubMed

Taha, Nessrin A; Albashaireh, Zakereyya S; Alfied, Rmdan G

2018-03-23

The aim of the study was to compare decision making for asymptomatic root-filled teeth among dentists with differing educational backgrounds. Case scenarios based on 14 radiographs were created and 150 participants were asked to choose from five alternative treatment decisions and to state the rationale. Demographic data of the participants were recorded. Frequency distribution and cross-tabulation were performed; chi square testing was used for comparisons and logistic regression was performed to detect significant differences. The overall response rate was 87.3%. The practitioners chose intervention predominantly with non-surgical retreatment a common choice. Poor technical quality was a driving factor, while the existing poor coronal restoration and the need for a crown were generally not taken into account by general dentists. Speciality and experience were significant factors. Practitioners were more inclined to retain rather than extract teeth. It is concluded that clear guidelines listing factors to consider for intervention are required. © 2018 Australian Society of Endodontology Inc.

Reciproc versus Twisted file for root canal filling removal: assessment of apically extruded debris.

PubMed

Altunbas, Demet; Kutuk, Betul; Toyoglu, Mustafa; Kutlu, Gizem; Kustarci, Alper; Er, Kursat

2016-01-01

The aim of this study was to evaluate the amount of apically extruded debris during endodontic retreatment with different file systems. Sixty extracted human mandibular premolar teeth were used in this study. Root canals of the teeth were instrumented and filled before being randomly assigned to three groups. Guttapercha was removed using the Reciproc system, the Twisted File system (TF), and Hedström-files (H-file). Apically extruded debris was collected and dried in pre-weighed Eppendorf tubes. The amount of extruded debris was assessed with an electronic balance. Data were statistically analyzed using one-way ANOVA, Kruskal-Wallis, and Mann-Whitney U tests. The Reciproc and TF systems extruded significantly less debris than the H-file (p<0.05). However, no significant difference was found between the Reciproc and TF systems. All tested file systems caused apical extrusion of debris. Both the rotary file (TF) and the reciprocating single-file (Reciproc) systems were associated with less apical extrusion compared with the H-file.

Evaluation of Root Canal Preparation Using Rotary System and Hand Instruments Assessed by Micro-Computed Tomography

PubMed Central

Stavileci, Miranda; Hoxha, Veton; Görduysus, Ömer; Tatar, Ilkan; Laperre, Kjell; Hostens, Jeroen; Küçükkaya, Selen; Muhaxheri, Edmond

2015-01-01

Background Complete mechanical preparation of the root canal system is rarely achieved. Therefore, the purpose of this study was to evaluate and compare the root canal shaping efficacy of ProTaper rotary files and standard stainless steel K-files using micro-computed tomography. Material/Methods Sixty extracted upper second premolars were selected and divided into 2 groups of 30 teeth each. Before preparation, all samples were scanned by micro-computed tomography. Thirty teeth were prepared with the ProTaper system and the other 30 with stainless steel files. After preparation, the untouched surface and root canal straightening were evaluated with micro-computed tomography. The percentage of untouched root canal surface was calculated in the coronal, middle, and apical parts of the canal. We also calculated straightening of the canal after root canal preparation. Results from the 2 groups were statistically compared using the Minitab statistical package. Results ProTaper rotary files left less untouched root canal surface compared with manual preparation in coronal, middle, and apical sector (p<0.001). Similarly, there was a statistically significant difference in root canal straightening after preparation between the techniques (p<0.001). Conclusions Neither manual nor rotary techniques completely prepared the root canal, and both techniques caused slight straightening of the root canal. PMID:26092929

Evaluation of Root Canal Preparation Using Rotary System and Hand Instruments Assessed by Micro-Computed Tomography.

PubMed

Stavileci, Miranda; Hoxha, Veton; Görduysus, Ömer; Tatar, Ilkan; Laperre, Kjell; Hostens, Jeroen; Küçükkaya, Selen; Muhaxheri, Edmond

2015-06-20

Complete mechanical preparation of the root canal system is rarely achieved. Therefore, the purpose of this study was to evaluate and compare the root canal shaping efficacy of ProTaper rotary files and standard stainless steel K-files using micro-computed tomography. Sixty extracted upper second premolars were selected and divided into 2 groups of 30 teeth each. Before preparation, all samples were scanned by micro-computed tomography. Thirty teeth were prepared with the ProTaper system and the other 30 with stainless steel files. After preparation, the untouched surface and root canal straightening were evaluated with micro-computed tomography. The percentage of untouched root canal surface was calculated in the coronal, middle, and apical parts of the canal. We also calculated straightening of the canal after root canal preparation. Results from the 2 groups were statistically compared using the Minitab statistical package. ProTaper rotary files left less untouched root canal surface compared with manual preparation in coronal, middle, and apical sector (p<0.001). Similarly, there was a statistically significant difference in root canal straightening after preparation between the techniques (p<0.001). Neither manual nor rotary techniques completely prepared the root canal, and both techniques caused slight straightening of the root canal.

Polymerization shrinkage stresses in different restorative techniques for non-carious cervical lesions.

PubMed

de Oliveira Correia, Ayla Macyelle; Tribst, João Paulo Mendes; de Souza Matos, Felipe; Platt, Jeffrey A; Caneppele, Taciana Marco Ferraz; Borges, Alexandre Luiz Souto

2018-06-20

This study evaluated the effect of different restorative techniques for non-carious cervical lesions (NCCL) on polymerization shrinkage stress of resins using three-dimensional (3D) finite element analysis (FEA). 3D-models of a maxillary premolar with a NCCL restored with different filling techniques (bulk filling and incremental) were generated to be compared by nonlinear FEA. The bulk filling technique was used for groups B (NCCL restored with Filtek™ Bulk Fill) and C (Filtek™ Z350 XT). The incremental technique was subdivided according to mode of application: P (2 parallel increments of the Filtek™ Z350 XT), OI (2 oblique increments of the Filtek™ Z350 XT, with incisal first), OIV (2 oblique increments of the Filtek™ Z350 XT, with incisal first and increments with the same volume), OG (2 oblique increments of the Filtek™ Z350 XT, with gingival first) and OGV (2 oblique increments of the Filtek™ Z350 XT, with gingival first and increments with the same volume), resulting in 7 models. All materials were considered isotropic, elastic and linear. The results were expressed in maximum principal stress (MPS). The tension stress distribution was influenced by the restorative technique. The lowest stress concentration occurred in group B followed by OG, OGV, OI, OIV, P and C; the incisal interface was more affected than the gingival. The restoration of NCCLs with bulk fill composite resulted in lower shrinkage stress in the gingival and incisal areas, followed by incremental techniques with the initial increment placed on the gingival wall. The non-carious cervical lesions (NCCLs) restored with bulk fill composite have a more favorable biomechanical behavior. Copyright © 2018. Published by Elsevier Ltd.

Arthroscopic Medial Meniscus Posterior Root Fixation Using a Modified Mason-Allen Stitch.

PubMed

Chung, Kyu Sung; Ha, Jeong Ku; Ra, Ho Jong; Kim, Jin Goo

2016-02-01

A complete radial tear of the meniscus posterior root, which can effectively cause a state of total meniscectomy via loss of hoop tension, requires that the torn root be repaired. Several methods have been used to repair medial meniscus posterior root tears, most of which are based on a simple stitch technique that is known to have stitch-holding strength. We applied a modified version of the Mason-Allen stitch technique, which is recognized as a method for rotator cuff repair surgery because its locking effect overcomes the potential weakness of simple stitches. This article introduces the medial meniscus posterior root tears repair procedure based on a modified Mason-Allen stitch technique in which 2 strands (i.e., 1 simple horizontal and 1 simple vertical stitch) are used.

Arthroscopic suture anchor repair of posterior root attachment injury in medial meniscus: technical note.

PubMed

Kim, Jae-Hwa; Shin, Dong-Eun; Dan, Jin-Myong; Nam, Ki-Shik; Ahn, Tae-Keun; Lee, Dong-Hoon

2009-08-01

A root attachment injury (root tear) of the meniscus can abolish the ability of the meniscus to bear hoop stress and predispose to increase articular contact stress which contribute to femorotibial degenerative changes. A pull out suture technique to repair the root tear has been described, but the procedure making the tibial tunnel may be difficult and troublesome. This article describes a repair technique using a suture anchor and posterior trans-septal portal.

A prospective study on transplantation of third molars with complete root formation.

PubMed

Mejàre, Bertil; Wannfors, Karin; Jansson, Leif

2004-02-01

The study objective was to evaluate the prognosis for autotransplantation of third molar teeth with fully developed roots followed by endodontic treatment on the basis of a time-table analysis. A total of 50 third molars with completely developed roots were autotransplanted to replace a lost first or second molar in the same number of admitted patients. Root canal treatment was started 3 to 4 weeks later. Clinical and radiographic checkup of the transplanted and root-filled third molars was done annually according to a predesigned record form. Descriptive statistics including a life table and statistical analysis were performed. The cumulative survival rate during 4 years' follow-up was 81.4%. In all, 7 transplants were lost during the follow-up time, 4 of them due to marginal periodontal pathosis and the other 3 due to root resorption. None of the root resorptions was observed before the second postoperative year. The radiographic periapical status was considered normal in 96% of the transplants at the latest follow-up visit. Autotransplantation of mature third molar teeth is a reasonable treatment alternative to conventional prosthetic rehabilitation or implant treatment in cases of partial edentualism from both a therapeutic and an economic point of view.

Monitoring Transcriptomic Changes in Soil-Grown Roots and Shoots of Arabidopsis thaliana Subjected to a Progressive Drought Stress.

PubMed

Bashir, Khurram; Rasheed, Sultana; Matsui, Akihiro; Iida, Kei; Tanaka, Maho; Seki, Motoaki

2018-01-01

Numerous experiments have been performed in Arabidopsis to monitor changes in gene expression that occur in response to a variety of abiotic and biotic stresses, different growth conditions, and at various developmental stages. In addition, gene expression patterns have also been characterized among wild-type and mutant genotypes. Despite these numerous reports, transcriptional changes occurring in roots of soil-grown plants subjected to a progressive drought stress have remained undocumented. To fill this gap, we established a system that allows one to establish water-deficit conditions and to collect root and shoot samples with minimal damage to the root system. Arabidopsis plants are grown in a ceramic-based granular soil and subjected to progressive drought stress by withholding water. Root and shoot samples were collected separately, RNA was purified, and a microarray analysis of drought-stressed roots and shoots was performed at 0, 1, 3, 5, 7, and 9 days after the onset of drought stress treatment. Here, we describe the detailed protocol used to analyze the transcriptomic changes occurring in roots and shoots of soil-grown Arabidopsis subjected to a progressive drought stress.

5-year results comparing mineral trioxide aggregate and adhesive resin composite for root-end sealing in apical surgery.

PubMed

von Arx, Thomas; Hänni, Stefan; Jensen, Simon Storgård

2014-08-01

Recent meta-analyses of the outcome of apical surgery using modern techniques including microsurgical principles and high-power magnification have yielded higher rates of healing. However, the information is mainly based on 1- to 2-year follow-up data. The present prospective study was designed to re-examine a large sample of teeth treated with apical surgery after 5 years. Patients were recalled 5 years after apical surgery, and treated teeth were classified as healed or not healed based on clinical and radiographic examination. (The latter was performed independently by 3 observers). Two different methods of root-end preparation and filling (primary study parameters) were to be compared (mineral trioxide aggregate [MTA] vs adhesive resin composite [COMP]) without randomization. A total of 271 patients and teeth from a 1-year follow-up sample of 339 could be re-examined after 5 years (dropout rate = 20.1%). The overall rate of healed cases was 84.5% with a significant difference (P = .0003) when comparing MTA (92.5%) and COMP (76.6%). The evaluation of secondary study parameters yielded no significant difference for healing outcome when comparing subcategories (ie, sex, age, type of tooth treated, post/screw, type of surgery). The results from this prospective nonrandomized clinical study with a 5-year follow-up of 271 teeth indicate that MTA exhibited a higher healing rate than COMP in the longitudinal prognosis of root-end sealing. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Sealing ability of cermet ionomer cement as a retrograde filling material.

PubMed

Aktener, B O; Pehlivan, Y

1993-03-01

An in vitro dye leakage study was performed to compare the sealing ability of high copper amalgam with cavity varnish and cermet ionomer cement with and without varnish when used as retrofilling materials. The root canals of 54 maxillary anterior teeth were instrumented and obturated with gutta-percha and sealer. The apical 3 mm of the roots were resected and apical class I cavity preparations were made. The roots were then randomly divided into three groups and retrofilled with one of the experimental materials. After 72 h of immersion in India ink, the roots were cleared and evaluated for leakage with a stereomicroscope. Statistical analysis indicated that the cermet ionomer cement with varnish group had significantly less leakage than the amalgam group (P < 0.0014) and the cermet ionomer cement without varnish group (P < 0.001). There was no significant difference between the other two groups (P > 0.05).

High-resolution synchrotron imaging shows that root hairs influence rhizosphere soil structure formation.

PubMed

Koebernick, Nicolai; Daly, Keith R; Keyes, Samuel D; George, Timothy S; Brown, Lawrie K; Raffan, Annette; Cooper, Laura J; Naveed, Muhammad; Bengough, Anthony G; Sinclair, Ian; Hallett, Paul D; Roose, Tiina

2017-10-01

In this paper, we provide direct evidence of the importance of root hairs on pore structure development at the root-soil interface during the early stage of crop establishment. This was achieved by use of high-resolution (c. 5 μm) synchrotron radiation computed tomography (SRCT) to visualise both the structure of root hairs and the soil pore structure in plant-soil microcosms. Two contrasting genotypes of barley (Hordeum vulgare), with and without root hairs, were grown for 8 d in microcosms packed with sandy loam soil at 1.2 g cm -3 dry bulk density. Root hairs were visualised within air-filled pore spaces, but not in the fine-textured soil regions. We found that the genotype with root hairs significantly altered the porosity and connectivity of the detectable pore space (> 5 μm) in the rhizosphere, as compared with the no-hair mutants. Both genotypes showed decreasing pore space between 0.8 and 0.1 mm from the root surface. Interestingly the root-hair-bearing genotype had a significantly greater soil pore volume-fraction at the root-soil interface. Effects of pore structure on diffusion and permeability were estimated to be functionally insignificant under saturated conditions when simulated using image-based modelling. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Integration and Improvement of Geophysical Root Biomass Measurements for Determining Carbon Credits

NASA Astrophysics Data System (ADS)

Boitet, J. I.

2013-12-01

Carbon trading schemes fundamentally rely on accurate subsurface carbon quantification in order for governing bodies to grant carbon credits inclusive of root biomass (What is Carbon Credit. 2013). Root biomass makes up a large chunk of the subsurface carbon and is difficult, labor intensive, and costly to measure. This paper stitches together the latest geophysical root measurement techniques into site-dependent recommendations for technique combinations and modifications that maximize large-scale root biomass measurement accuracy and efficiency. "Accuracy" is maximized when actual root biomass is closest to measured root biomass. "Efficiency" is maximized when time, labor, and cost of measurement is minimized. Several combinations have emerged which satisfy both criteria under different site conditions. Use of ground penetrating radar (GPR) and/or electrical resistivity tomography (ERT) allow for large tracts of land to be surveyed under appropriate conditions. Among other characteristics, GPR does best with detecting coarse roots in dry soil. ERT does best in detecting roots in moist soils, but is especially limited by electrode configuration (Mancuso, S. 2012). Integration of these two technologies into a baseline protocol based on site-specific characteristics, especially soil moisture and plants species heterogeneity, will drastically theoretically increase efficiency and accuracy of root biomass measurements. Modifications of current measurement protocols using these existing techniques will also theoretically lead to drastic improvements in both accuracy and efficiency. These modifications, such as efficient 3D imaging by adding an identical electrode array perpendicular to the first array used in the Pulled Array Continuous Electrical Profiling (PACEP) technique for ERT, should allow for more widespread application of these techniques for understanding root biomass. Where whole-site measurement is not feasible either due to financial, equipment, or physical limitations, measurements from randomly selected plots must be assumed representative of the entire system and scaled up. This scaling introduces error roughly inversely proportional to the number and size of plots measured. References Mancuso, S. (2012). Measuring roots: An updated approach Springer. What is carbon credit. (2013). Retrieved 7/20, 2013, from http://carbontradexchange.com/knowledge/what-is-carbon-credit

Meniscus root repair.

PubMed

Vyas, Dharmesh; Harner, Christopher D

2012-06-01

Root tears are a subset of meniscal injuries that result in significant knee joint pathology. Occurring on either the medial or lateral side, root tears are defined as radial tears or avulsions of the posterior horn attachment to bone. After a root tear, there is a significant increase in tibio-femoral contact pressure concomitant with altered knee joint kinematics. Previous cadaver studies from our institution have shown that root repair of the medial meniscus is successful in restoring joint biomechanics to within normal limits. Indications for operative management of meniscal root tears include (1) a symptomatic medial meniscus root tear with minimal arthritis and having failed non-operative treatment, and (2) a lateral root tear in associated with an ACL tear. In this review, we describe diagnosis, imaging, patient selection, and arthroscopic surgical technique of medial and lateral meniscus root injuries. In addition we highlight the pearls of repair technique, associated complications, post-operative rehabilitation regimen, and expected outcomes.

Contrast-to-noise ratio with different settings in a CBCT machine in presence of different root-end filling materials: an in vitro study.

PubMed

Demirturk Kocasarac, Husniye; Helvacioglu Yigit, Dilek; Bechara, Boulos; Sinanoglu, Alper; Noujeim, Marcel

2016-01-01

To compare the contrast-to-noise ratio (CNR) of multiple acquisition settings for four types of retrograde filling materials in CBCT images taken for endodontic surgery follow-up. 20 maxillary central incisors were endodontically treated and obturated with 4 different root-end filling materials: amalgam, mineral trioxide aggregate, SuperEBA(™) (Harry J Bosworth Company, Skokie, IL) and Biodentine™ (Septodont, Saint-Maur-des-Faussés, France). Teeth were placed in a skull and scanned, one by one, with the Planmeca ProMax(®) 3D Max (Planmeca, Helsinki, Finland); at different voltages: 66, 76, 84 and 96 kVp; with low, normal and high resolution and high definition (HD); with and without metal artefact reduction (MAR). Images were analyzed using ImageJ software (National Institutes of Health, Bethesda, MD) to calculate the CNR. The dose-area product was registered, and the effective dose calculated. No statistically significant difference was noted between the four materials. 84 and 96 kVp with low resolution and the use of MAR-generated images that have statistically better CNR than 66 and 76 kVp with HD, normal and high resolutions and without MAR. The use of low resolution also generated the smallest value of effective dose. The best setting for radiographic follow-up in an endodontic surgery with retrograde filling on the Planmeca ProMax is 96 kVp with low resolution and high MAR; this setting produced one of the lowest effective doses.

A smart rotary technique versus conventional pulpectomy for primary teeth: A randomized controlled clinical study

PubMed Central

Mokhtari, Negar; Shirazi, Alireza-Sarraf

2017-01-01

Background Techniques with adequate accuracy of working length determination along with shorter duration of treatment in pulpectomy procedure seems to be essential in pediatric dentistry. The aim of the present study was to evaluate the accuracy of root canal length measurement with Root ZX II apex locator and rotary system in pulpectomy of primary teeth. Material and Methods In this randomized control clinical trial complete pulpectomy was performed on 80 mandibular primary molars in 80, 4-6-year-old children. The study population was randomly divided into case and control groups. In control group conventional pulpectomy was performed and in the case group working length was determined by electronic apex locator Root ZXII and instrumented with Mtwo rotary files. Statistical evaluation was performed using Mann-Whitney and Chi-Square tests (P<0.05). Results There were no significant differences between electronic apex locator Root ZXII and conventional method in accuracy of root canal length determination. However significantly less time was needed for instrumenting with rotary files (P=0.000). Conclusions Considering the comparable results in accuracy of root canal length determination and the considerably shorter instrumentation time in Root ZXII apex locator and rotary system, it may be suggested for pulpectomy in primary molar teeth. Key words:Rotary technique, conventional technique, pulpectomy, primary teeth. PMID:29302280

A smart rotary technique versus conventional pulpectomy for primary teeth: A randomized controlled clinical study.

PubMed

Mokhtari, Negar; Shirazi, Alireza-Sarraf; Ebrahimi, Masoumeh

2017-11-01

Techniques with adequate accuracy of working length determination along with shorter duration of treatment in pulpectomy procedure seems to be essential in pediatric dentistry. The aim of the present study was to evaluate the accuracy of root canal length measurement with Root ZX II apex locator and rotary system in pulpectomy of primary teeth. In this randomized control clinical trial complete pulpectomy was performed on 80 mandibular primary molars in 80, 4-6-year-old children. The study population was randomly divided into case and control groups. In control group conventional pulpectomy was performed and in the case group working length was determined by electronic apex locator Root ZXII and instrumented with Mtwo rotary files. Statistical evaluation was performed using Mann-Whitney and Chi-Square tests ( P <0.05). There were no significant differences between electronic apex locator Root ZXII and conventional method in accuracy of root canal length determination. However significantly less time was needed for instrumenting with rotary files ( P =0.000). Considering the comparable results in accuracy of root canal length determination and the considerably shorter instrumentation time in Root ZXII apex locator and rotary system, it may be suggested for pulpectomy in primary molar teeth. Key words: Rotary technique, conventional technique, pulpectomy, primary teeth.

Comprehensive comparison of gap filling techniques for eddy covariance net carbon fluxes

NASA Astrophysics Data System (ADS)

Moffat, A. M.; Papale, D.; Reichstein, M.; Hollinger, D. Y.; Richardson, A. D.; Barr, A. G.; Beckstein, C.; Braswell, B. H.; Churkina, G.; Desai, A. R.; Falge, E.; Gove, J. H.; Heimann, M.; Hui, D.; Jarvis, A. J.; Kattge, J.; Noormets, A.; Stauch, V. J.

2007-12-01

Review of fifteen techniques for estimating missing values of net ecosystem CO2 exchange (NEE) in eddy covariance time series and evaluation of their performance for different artificial gap scenarios based on a set of ten benchmark datasets from six forested sites in Europe. The goal of gap filling is the reproduction of the NEE time series and hence this present work focuses on estimating missing NEE values, not on editing or the removal of suspect values in these time series due to systematic errors in the measurements (e.g. nighttime flux, advection). The gap filling was examined by generating fifty secondary datasets with artificial gaps (ranging in length from single half-hours to twelve consecutive days) for each benchmark dataset and evaluating the performance with a variety of statistical metrics. The performance of the gap filling varied among sites and depended on the level of aggregation (native half- hourly time step versus daily), long gaps were more difficult to fill than short gaps, and differences among the techniques were more pronounced during the day than at night. The non-linear regression techniques (NLRs), the look-up table (LUT), marginal distribution sampling (MDS), and the semi-parametric model (SPM) generally showed good overall performance. The artificial neural network based techniques (ANNs) were generally, if only slightly, superior to the other techniques. The simple interpolation technique of mean diurnal variation (MDV) showed a moderate but consistent performance. Several sophisticated techniques, the dual unscented Kalman filter (UKF), the multiple imputation method (MIM), the terrestrial biosphere model (BETHY), but also one of the ANNs and one of the NLRs showed high biases which resulted in a low reliability of the annual sums, indicating that additional development might be needed. An uncertainty analysis comparing the estimated random error in the ten benchmark datasets with the artificial gap residuals suggested that the techniques are already at or very close to the noise limit of the measurements. Based on the techniques and site data examined here, the effect of gap filling on the annual sums of NEE is modest, with most techniques falling within a range of ±25 g C m-2 y-1.

Philosophical Issues in Adventure Education.

ERIC Educational Resources Information Center

Wurdinger, Scott D.

Adventure education is filled with "doers," which improves practice but does not necessarily enhance theory. This book addresses that gap by examining the philosophy of adventure education. Chapter 1 examines foundational principles, which have their roots in the ideas of philosophers such as Plato, Aristotle, Rousseau, and Dewey, and…

In vitro study of calcium hydroxide removal from mandibular molar root canals.

PubMed

Ma, Jingzhi; Shen, Ya; Yang, Yan; Gao, Yuan; Wan, Pan; Gan, Yan; Patel, Payal; Curtis, Allison; Khakpour, Mehrzad; Haapasalo, Markus

2015-04-01

Previous studies have shown the difficulty in removing calcium hydroxide (Ca[OH]2) paste from the root canals before root filling. Mesial and distal canals of 30 mandibular molars were prepared with the WaveOne Primary (25/.08) and Large file (40/.08) (Dentsply Tulsa Dental Specialties, Tulsa, OK), respectively. All canals were then filled with Ca(OH)2. The teeth were divided into the following 3 treatment groups (each with n = 10): (1) instrumentation with needle irrigation, (2) instrumentation with irrigation and passive ultrasonic activation (PUI), and (3) the GentleWave system (Sonendo, Inc, Laguna Hills, CA) without instrumentation. The irrigation time in each group was 7.5 minutes. To further test the efficiency of the GentleWave system, shorter times of 90 seconds were tested using water alone. Reconstructed micro-computed tomographic scans were used to measure the volume of the canals and Ca(OH)2 after instrumentation, initial filling of Ca(OH)2, and after its removal. The percentage of Ca(OH)2 remaining in the canals was calculated. None of the 10 teeth (30 canals) in the conventional irrigation and PUI groups were completely cleaned of Ca(OH)2 in 7.5 minutes. In the apical third of mesial and distal canals, respectively, conventional irrigation removed 47.82% ± 16.36% and 77.68% ± 12.82%, PUI removed 61.66% ± 25.54% and 88.85 ± 12.06%, and the GentleWave system removed significantly more Ca(OH)2 (P < .05) with 100% and 98.78% ± 3.84%. Additional experiments in 10 teeth, using only water as the irrigant, revealed that the GentleWave system removed 99.85% and 99.97% of Ca(OH)2 within 90 seconds without the use of any instruments in the mesial and distal canals, respectively. The study confirms the difficulty to remove Ca(OH)2 from root canals using conventional methods. The GentleWave system removed the paste within 90 seconds using water irrigation alone. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Bioactivity, cytocompatibility and thermal properties of experimental Bioglass-reinforced composites as potential root-canal filling materials.

PubMed

Alhashimi, Raghad Abdulrazzaq; Mannocci, Francesco; Sauro, Salvatore

2017-05-01

To evaluate the bioactivity and the cytocompatibility of experimental Bioglass-reinforced polyethylene-based root-canal filling materials. The thermal properties of the experimental materials were also evaluated using differential scanning calorimetry, while their radiopacity was assessed using a grey-scale value (GSV) aluminium step wedge and a phosphor plate digital system. Bioglass 45S5 (BAG), polyethylene and Strontium oxide (SrO) were used to create tailored composite fibres. The filler distribution within the composites was assessed using SEM, while their bioactivity was evaluated through infrared spectroscopy (FTIR) after storage in simulated body fluid (SBF). The radiopacity of the composite fibres and their thermal properties were determined using differential scanning calorimetry (DSC). The cytocompatibility of the experimental composites used in this study was assessed using human osteoblasts and statistically analysed using the Pairwise t-test (p<0.05). Bioglass and SrO fillers were well distributed within the resin matrix and increased both the thermal properties and the radiopacity of the polyethylene matrix. The FTIR showed a clear formation of calcium-phosphates, while, MTT and AlamrBlue tests demonstrated no deleterious effects on the metabolic activity of the osteoblast-like cells. BAG-reinforced polyethylene composites may be suitable as obturation materials for endodontic treatment. Since their low melting temperature, such innovative composites may be easily removed in case of root canal retreatment. Moreover, their biocompatibility and bioactivity may benefit proliferation of human osteoblast cells at the periapical area of the root. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fibrin gel improves tissue ingrowth and cell differentiation in human immature premolars implanted in rats.

PubMed

Ruangsawasdi, Nisarat; Zehnder, Matthias; Weber, Franz E

2014-02-01

In pulpless immature human premolars implanted in rodents, this study investigated whether fibrin gel offered advantages over leaving the root canal empty regarding soft tissue ingrowth and cell differentiation. Root canals of extracted human immature premolars (n = 12) were accessed and then irrigated with 5% sodium hypochlorite followed by 17% ethylenediaminetetraacetic acid. Root canals were then either left empty or filled with a fibrin gel (n = 6 each) before being placed subcutaneously on top of the calvarial bone of rats (1 tooth per rat) for 12 weeks. After sacrifice, teeth were histologically assessed. Tissue ingrowth was quantified and compared between groups using the Mann-Whitney U test (P < .05). Cells adhering to the pulp canal wall were immunohistochemically screened for the presence of bone sialoprotein (BSP) and dentin sialoprotein (DSP). More tissue grew into the pulp space when teeth were filled with fibrin gel (P < .05). The presence of fibrin gel affected not only the extent of tissue ingrowth but also tissue morphology and differentiation of cells contacting the dentinal wall. In the fibrin gel group, newly formed tissue was similar to normal pulp, constituted of inner pulp, cell-rich zone, cell-free zone, and an apparent odontoblast layer, which stained positive for BSP and DSP. Newly formed blood vessels were also more abundant compared with the initially empty root canals. Under the conditions of this study, fibrin gel improved cell infiltration and cell-dentin interaction. Both are necessary for pulp tissue regeneration. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Revascularization and Apical Plug in an Immature Molar

PubMed Central

Roghanizadeh, Leyla; Fazlyab, Mahta

2018-01-01

Managing of necrotic permanent teeth with immature apices is a treatment challenges. Treatment of such teeth includes apexification, apical plug and more recently, revascularization technique with the probable advantage of continuation of root development. In the present case report the referred patient had discomfort with a necrotic immature mandibular first molar. Periapical radiography showed a rather large apical lesion around immature roots. Revascularization protocol using calcium-enriched mixture (CEM) cement was indicated for the mesial root. However, in distal canal apical plug technique was applied. At 2-year follow-up, both procedures were successful in relieving patient’s symptoms. Dentin formation and increase in length of the mesial root was obvious. Apical plug and revascularization technique proved to be successful in management of necrotic immature teeth; moreover, revascularization carried the advantage of continuation of root development. PMID:29692851

Avulsion of the anterior medial meniscus root: case report and surgical technique.

PubMed

Feucht, Matthias J; Minzlaff, Philipp; Saier, Tim; Lenich, Andreas; Imhoff, Andreas B; Hinterwimmer, Stefan

2015-01-01

Injuries of the meniscus roots have become increasingly recognised as a serious pathology of the knee joint. However, the current available literature focuses primarily on posterior meniscus root tears. In this article, a case with an isolated avulsion of the anterior medial meniscus root is presented, and a new arthroscopic technique to treat this type of injury is described. The anterior horn of the medial meniscus was sutured with a double-looped nonabsorbable suture and reattached to the tibial plateau using a knotless suture anchor. This technique may also be useful to treat avulsion injuries of the anterolateral or posteromedial meniscus root, and symptomatic subluxation of the medial meniscus in case of a variant insertion anatomy with an absent attachment of the anterior horn of the medial meniscus to the tibial plateau. Level of evidence V.

Experimentally reduced root-microbe interactions reveal limited plasticity in functional root traits in Acer and Quercus.

PubMed

Lee, Mei-Ho; Comas, Louise H; Callahan, Hilary S

2014-02-01

Interactions between roots and soil microbes are critical components of below-ground ecology. It is essential to quantify the magnitude of root trait variation both among and within species, including variation due to plasticity. In addition to contextualizing the magnitude of plasticity relative to differences between species, studies of plasticity can ascertain if plasticity is predictable and whether an environmental factor elicits changes in traits that are functionally advantageous. To compare functional traits and trait plasticities in fine root tissues with natural and reduced levels of colonization by microbial symbionts, trimmed and surface-sterilized root segments of 2-year-old Acer rubrum and Quercus rubra seedlings were manipulated. Segments were then replanted into satellite pots filled with control or heat-treated soil, both originally derived from a natural forest. Mycorrhizal colonization was near zero in roots grown in heat-treated soil; roots grown in control soil matched the higher colonization levels observed in unmanipulated root samples collected from field locations. Between-treatment comparisons revealed negligible plasticity for root diameter, branching intensity and nitrogen concentration across both species. Roots from treated soils had decreased tissue density (approx. 10-20 %) and increased specific root length (approx. 10-30 %). In contrast, species differences were significant and greater than treatment effects in traits other than tissue density. Interspecific trait differences were also significant in field samples, which generally resembled greenhouse samples. The combination of experimental and field approaches was useful for contextualizing trait plasticity in comparison with inter- and intra-specific trait variation. Findings that root traits are largely species dependent, with the exception of root tissue density, are discussed in the context of current literature on root trait variation, interactions with symbionts and recent progress in standardization of methods for quantifying root traits.

Spatial and directional variation of growth rates in Arabidopsis root apex: a modelling study.

PubMed

Nakielski, Jerzy; Lipowczan, Marcin

2013-01-01

Growth and cellular organization of the Arabidopsis root apex are investigated in various aspects, but still little is known about spatial and directional variation of growth rates in very apical part of the apex, especially in 3D. The present paper aims to fill this gap with the aid of a computer modelling based on the growth tensor method. The root apex with a typical shape and cellular pattern is considered. Previously, on the basis of two types of empirical data: the published velocity profile along the root axis and dimensions of cell packets formed in the lateral part of the root cap, the displacement velocity field for the root apex was determined. Here this field is adopted to calculate the linear growth rate in different points and directions. The results are interpreted taking principal growth directions into account. The root apex manifests a significant anisotropy of the linear growth rate. The directional preferences depend on a position within the root apex. In the root proper the rate in the periclinal direction predominates everywhere, while in the root cap the predominating direction varies with distance from the quiescent centre. The rhizodermis is distinguished from the neighbouring tissues (cortex, root cap) by relatively high contribution of the growth rate in the anticlinal direction. The degree of growth anisotropy calculated for planes defined by principal growth directions and exemplary cell walls may be as high as 25. The changes in the growth rate variation are modelled.

Postoperative pain intensity after using different instrumentation techniques: a randomized clinical study

PubMed Central

ÇIÇEK, Ersan; KOÇAK, Mustafa Murat; KOÇAK, Sibel; SAĞLAM, Baran Can; TÜRKER, Sevinç Aktemur

2017-01-01

Abstract Postoperative pain is a frequent complication associated with root canal treatment, especially during apical instrumentation of tooth with preexisting periradicular inflammation Objectives The aim of this clinical study was to evaluate the influence of the instrumentation techniques on the incidence and intensity of postoperative pain in single-visit root canal treatment. Material and Methods Ninety patients with single root/canal and non-vital pulps were included. The patients were assigned into 3 groups according to root canal instrumentation technique used; modified step-back, reciprocal, and rotational techniques. Root canal treatment was carried out in a single visit and the severity of postoperative pain was assessed via 4-point pain intensity scale. All the participants were called through the phone at 12, 24 and 48 h to obtain the pain scores. Data were analyzed through the Kruskal–Wallis test. Results There was significant difference between all groups (p<0.05). The modified step-back technique produced postoperative pain significantly lower than the rotational (p=0.018) and reciprocal (p=0.020) techniques. No difference was found between the reciprocal and rotational techniques (p=0.868). Postoperative pain in the first 12 h period (p=0.763) and in the 24 h period (p=0.147) was not significantly different between the groups. However, the difference in the 48 h period was statistically different between the groups (p=0.040). Conclusion All instrumentation techniques caused postoperative pain. The modified step-back technique produced less pain compared to the rotational and reciprocal techniques. PMID:28198972

Coverage Root after Removing Peripheral Ossifying Fibroma: 5-Year Follow-Up Case Report

PubMed Central

Okajima, Luciana S.; Nunes, Marcelo P.; Montalli, Victor A. M.

2016-01-01

When lesions in soft tissue reach the gingival margin, they can produce aesthetic defects during its permanence and after its removal. Periodontal plastic surgery allows the correction of the gingival contour using different techniques. This paper is a case report of a peripheral ossifying fibroma removal in the interproximal area of teeth 21 and 22 in addition to root coverage of the affected area through two surgical phases: keratinized gingival tissue augmentation surgery with free gingival graft concurrent with removal of the lesion and, in a second stage, root coverage by performing coronally advanced flap technique with a follow-up of five years. The initial results achieved, which were root coverage of 100% after 6 months, promoted an adequate gingival contour and prevented the development of a mucogingival defect or a root exposure with its functional and aesthetic consequences. After five years, the results showed long term success of the techniques, where the margin remained stable with complete root coverage and tissues were stable and harmonic in color. PMID:27891263

Coverage Root after Removing Peripheral Ossifying Fibroma: 5-Year Follow-Up Case Report.

PubMed

Henriques, Paulo S G; Okajima, Luciana S; Nunes, Marcelo P; Montalli, Victor A M

2016-01-01

When lesions in soft tissue reach the gingival margin, they can produce aesthetic defects during its permanence and after its removal. Periodontal plastic surgery allows the correction of the gingival contour using different techniques. This paper is a case report of a peripheral ossifying fibroma removal in the interproximal area of teeth 21 and 22 in addition to root coverage of the affected area through two surgical phases: keratinized gingival tissue augmentation surgery with free gingival graft concurrent with removal of the lesion and, in a second stage, root coverage by performing coronally advanced flap technique with a follow-up of five years. The initial results achieved, which were root coverage of 100% after 6 months, promoted an adequate gingival contour and prevented the development of a mucogingival defect or a root exposure with its functional and aesthetic consequences. After five years, the results showed long term success of the techniques, where the margin remained stable with complete root coverage and tissues were stable and harmonic in color.

New minimally invasive discectomy technique through the interlaminar space using a percutaneous endoscope.

PubMed

Dezawa, A; Sairyo, K

2011-05-01

The serial dilating technique used to access herniated discs at the L5-S1 space using percutaneous endoscopic discectomy (PED) via an 8 mm skin incision can possibly injure the S1 nerve root. In this paper, we describe in detail a new surgical procedure to safely access the disc and to avoid the nerve root damage. This small-incision endoscopic technique, small-incision microendoscopic discectomy (sMED), mimics microendoscopic discectomy and applies PED. The sMED approach is similar to the well-established microendoscopic discectomy technique. To secure the surgical field, a duckbill-type PED cannula is used. Following laminotomy of L5 using a high-speed drill, the ligamentum flavum is partially removed using the Kerrison rongeur. Using the curved nerve root retractor, the S1 nerve root is gradually and gently moved caudally. Following the compete retraction of the S1 nerve root to the caudal side of the herniated nucleus pulposus (HNP), the nerve root is retracted safely medially and caudally using the bill side of the duckbill PED cannula. Next, using the HNP rongeur for PED, the HNP is removed piece by piece until the nerve root is decompressed. A total of 30 patients with HNP at the L5-S1 level underwent sMED. In all cases, HNP was successfully removed and patients showed improvement following surgery. Only one patient complained of moderate radiculopathy at the final visit. No complications were encountered. We introduced a minimally invasive technique to safely remove HNP at the L5-S1 level. sMED is possibly the least invasive technique for HNP removal at the L5-S1 level. © 2011 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and Blackwell Publishing Asia Pty Ltd.

Growing up as a Young Artist

ERIC Educational Resources Information Center

Szekely, George

2012-01-01

"Growing Up as a Young Artist" is an illustrated book assignment that involves researching family scrapbooks, photo albums and films, and inquiring about family anecdotes for clues to one's artistic roots. Students creatively reflect on their early memories of imaginative events, as each page is filled with memories of creative activities they…

The effect of modifying rooting depths and nitrification inhibitors on nutrient uptake from organic biogas residues in maize

NASA Astrophysics Data System (ADS)

Dietrich, Charlotte C.; Koller, Robert; Nagel, Kerstin A.; Schickling, Anke; Schrey, Silvia D.; Jablonowski, Nicolai D.

2017-04-01

Optimizing the application of and nutrient uptake from organic nutrient sources, such as the nutrient-rich residues ("digestates") from the biogas industry, is becoming a viable option in remediating fertility on previously unsuitable soils for agricultural utilization. Proposedly, concurrent changes in root system architecture and functioning could also serve as the basis of future phytomining approaches. Herein, we evaluate the effect of spatial nutrient availability and nitrification on maize root architecture and nutrient uptake. We test these effects by applying maize-based digestate at a rate of 170 kg/ha in layers of varying depths (10, 25 and 40 cm) and through either the presence or absence of nitrification inhibitors. In order to regularly monitor above- and below-ground plant biomass production, we used the noninvasive phenotyping platform, GROWSCREEN-Rhizo at the Forschungszentrum Jülich, using rhizotrons (Nagel et al., 2012). Measured parameters included projected plant height and leaf area, as well as root length and spatial distribution. Additionally, root diameters were quantified after the destructive harvest, 21 days after sowing (DAS). Spatial nutrient availability significantly affected root system architecture, as for example root system size -the area occupied by roots- increased alongside nutrient layer depths. Fertilization also positively affected root length density (RLD). Within fertilized layers, the presence of nitrification inhibitors increased RLD by up to 30% and was most pronounced in the fine root biomass fraction (0.1 to 0.5mm). Generally, nitrification inhibitors promoted early plant growth by up to 45% across treatments. However, their effect varied in dependence of layer depths, leading to a time-delayed response in deeper layers, accounting for plants having to grow significantly longer roots in order to reach fertilized substrate. Nitrification inhibitors also initiated the comparatively early on-set of growth differences in shallower layers, where their effect on plant growth was temporarily most pronounced. At final harvest (21 DAS) however, effects of nitrification inhibitors on plant height were visible only in deeper layers. Furthermore, the statistically significant interaction between the factors time x layer depths x nitrification inhibitors underlined the dynamic influence of nitrification inhibitors on plant growth over time and across rooting depths. This study offers insights into optimizing nutrient uptake and plant productivity by (re-) using residues from the biogas industry. It is among the first to monitor and try to explain the dynamics of nitrification inhibitors on root system architecture over time. A modified N-fertilization application scheme might also serve as a promising tool in optimizing phytoremediation and phytomining techniques through predictably altering root structure in fertilized layers. References: Nagel, K. A. ; Putz, A. ; Gilmer, F. ; Heinz, K. ; Fischbach, A. ; Pfeifer, J. ; Faget, M. ; Blossfeld, S. ; Ernst, M. ; Dimaki, C. ; Kastenholz, B. ; Kleinert, A.-K. ; Galinski, A. ; Scharr, H. ; Fiorani, F. ; Schurr, U. (2012): GROWSCREEN-Rhizo is a novel phenotyping robot enabling simultaneous measurements of root and shoot growth for plants grown in soil-filled rhizotrons.
Functional plant biology 39(11), 891-904.

A Limited Study of the Performance of an Interim 3/4-Ton Wheel/Track Convertible Test Rig, Houghton, Michigan, and Vicksburg, Mississippi

DTIC Science & Technology

1974-04-01

praaaad down graaaee 4 Boaaaa: very little rutting 2-1/2 Soaa alight eurface water: dark organic naterlal beginning to appear 3-1/2 Ruta filled with...Significant rutting nearly complete by thla paa» 5-1/4 Very little change In ruta 5-1/2 Vehicle had CMpacted «et ayace« to vary hard 2 in. layer...of fibera thet prevented aignlflcant rutting, com- pleted 50 paaaee with eaae. 4-1/2 Vehicle preeeed «oaa and root «at down and ruta began filling

WE-E-213CD-01: Best in Physics (Joint Imaging-Therapy) - Evaluation of Deformation Algorithm Accuracy with a Two-Dimensional Anatomical Pelvic Phantom.

PubMed

Kirby, N; Chuang, C; Pouliot, J

2012-06-01

To objectively evaluate the accuracy of 11 different deformable registration techniques for bladder filling. The phantom represents an axial plane of the pelvic anatomy. Urethane plastic serves as the bony anatomy and urethane rubber with three levels of Hounsfield units (HU) is used to represent fat and organs, including the prostate. A plastic insert is placed into the phantom to simulate bladder filling. Nonradiopaque markers reside on the phantom surface. Optical camera images of these markers are used to measure the positions and determine the deformation from the bladder insert. Eleven different deformable registration techniques are applied to the full- and empty-bladder computed tomography images of the phantom to calculate the deformation. The applied algorithms include those from MIMVista Software and Velocity Medical Solutions and 9 different implementations from the Deformable Image Registration and Adaptive Radiotherapy Toolbox for Matlab. The distance to agreement between the measured and calculated deformations is used to evaluate algorithm error. Deformable registration warps one image to make it similar to another. The root-mean-square (RMS) difference between the HUs at the marker locations on the empty-bladder phantom and those at the calculated marker locations on the full-bladder phantom is used as a metric for image similarity. The percentage of the markers with an error larger than 3 mm ranges from 3.1% to 28.2% with the different registration techniques. This range is 1.1% to 3.7% for a 7 mm error. The least accurate algorithm at 3 mm is also the most accurate at 7 mm. Also, the least accurate algorithm at 7 mm produces the lowest RMS difference. Different deformation algorithms generate very different results and the outcome of any one algorithm can be misleading. Thus, these algorithms require quality assurance. The two-dimensional phantom is an objective tool for this purpose. © 2012 American Association of Physicists in Medicine.

Canal transportation after root canal instrumentation: a comparative study with computed tomography.

PubMed

Hartmann, Mateus Silveira Martins; Barletta, Fernando Branco; Camargo Fontanella, Vânia Regina; Vanni, José Roberto

2007-08-01

This in vitro study used computed tomography (CT) to compare the occurrence of canal transportation in the apical third of mesiobuccal canals in maxillary molars instrumented with 3 techniques. Sixty teeth were assigned to 3 groups (n = 20), and the root canals were instrumented as follows: Group 1, hand instrumentation with K-files; Group 2, K-files coupled to an oscillatory system powered by an electric engine; Group 3, ProTaper NiTi rotary system powered by an electric engine. To compare the canal transportation produced by the different techniques, preinstrumentation and postinstrumentation 3-dimensional CT images were obtained from root cross-sections of the region located 3 mm short of the apical foramen of each root canal. The CT scans were exported to Adobe Photoshop software, and the initial and final images were superimposed to detect the root canal wall differences between them. Canal transportation was measured by the distance between the prepared canal center and the anatomic canal center. The manual technique produced lesser canal transportation (0.10 mm) than the oscillatory and rotary techniques (0.37 and 0.22 mm, respectively); this difference was statistically significant (P=.021). All studied techniques produced canal transportation.

Peroxidases, lignin and anatomy during in vitro and ex vitro rooting of gardenia (Gardenia jasminoides Ellis) microshoots.

PubMed

Hatzilazarou, Stefanos P; Syros, Thomas D; Yupsanis, Traianos A; Bosabalidis, Artemios M; Economou, Athanasios S

2006-07-01

In vitro and ex vitro rooting of gardenia (Gardenia jasminoides Ellis) microshoots with or without indolic-3-butyric acid (IBA) was studied in order to improve acclimatization of microplants after root formation and transplantation. Peroxidase (POD) activity and isoforms, lignin content and anatomical observations were evaluated in the course of the three interdependent phases (induction, initiation and expression) of microshoot rooting. Microshoots treated or not treated with IBA achieved high rooting percentages both in vitro and ex vitro. At the end of the 2-week acclimatization period, the percentage of surviving microplants ranged from 80% to 100%, for in vitro and ex vitro rooted microshoots, respectively. Microshoots rooted in vitro and ex vitro showed a relationship between rooting and POD activity but in a different time course. It appeared that root formation occurred after the microshoots had reached and passed a peak of maximum enzyme activity. In all treatments, electrophoretic analysis (native PAGE) of PODs revealed the appearance of one anionic and three cationic POD isoforms (C(1), C(3) and C(4)). An additional cationic POD isoform (C(2)) appeared only in the ex vitro rooting. The lignin content was similar in microshoots rooted both in vitro and ex vitro. The sequential anatomical changes during the rooting process were similar in both in vitro and ex vitro rooting treatments. In the case of in vitro rooting, pith cells had vacuoles entirely filled with a dark substance, while in the case of ex vitro rooting, pith cells contained many amyloplasts. The origin of the adventitious roots, in both rooting conditions, was located in the cambial ring. Roots with organized tissue systems emerged from the microshoot stem 10-14 days after the root induction treatments; on day 10 for rooting in vitro, while a 4-day delay was noted in microshoots rooted ex vitro.

Image compression technique

DOEpatents

Fu, Chi-Yung; Petrich, Loren I.

1997-01-01

An image is compressed by identifying edge pixels of the image; creating a filled edge array of pixels each of the pixels in the filled edge array which corresponds to an edge pixel having a value equal to the value of a pixel of the image array selected in response to the edge pixel, and each of the pixels in the filled edge array which does not correspond to an edge pixel having a value which is a weighted average of the values of surrounding pixels in the filled edge array which do correspond to edge pixels; and subtracting the filled edge array from the image array to create a difference array. The edge file and the difference array are then separately compressed and transmitted or stored. The original image is later reconstructed by creating a preliminary array in response to the received edge file, and adding the preliminary array to the received difference array. Filling is accomplished by solving Laplace's equation using a multi-grid technique. Contour and difference file coding techniques also are described. The techniques can be used in a method for processing a plurality of images by selecting a respective compression approach for each image, compressing each of the images according to the compression approach selected, and transmitting each of the images as compressed, in correspondence with an indication of the approach selected for the image.

Image compression technique

DOEpatents

Fu, C.Y.; Petrich, L.I.

1997-03-25

An image is compressed by identifying edge pixels of the image; creating a filled edge array of pixels each of the pixels in the filled edge array which corresponds to an edge pixel having a value equal to the value of a pixel of the image array selected in response to the edge pixel, and each of the pixels in the filled edge array which does not correspond to an edge pixel having a value which is a weighted average of the values of surrounding pixels in the filled edge array which do correspond to edge pixels; and subtracting the filled edge array from the image array to create a difference array. The edge file and the difference array are then separately compressed and transmitted or stored. The original image is later reconstructed by creating a preliminary array in response to the received edge file, and adding the preliminary array to the received difference array. Filling is accomplished by solving Laplace`s equation using a multi-grid technique. Contour and difference file coding techniques also are described. The techniques can be used in a method for processing a plurality of images by selecting a respective compression approach for each image, compressing each of the images according to the compression approach selected, and transmitting each of the images as compressed, in correspondence with an indication of the approach selected for the image. 16 figs.

Influence of apical enlargement on the repair of apical periodontitis in rats.

PubMed

Jara, C M; Hartmann, R C; Böttcher, D E; Souza, T S; Gomes, M S; Figueiredo, J A P

2018-05-08

To evaluate the influence of different apical enlargement protocols on the radiographic and histological healing of apical periodontitis in rats. Apical periodontitis was induced bilaterally in the mandibular right and left first molars of 24 Wistar rats by pulp exposure to the oral cavity for 3 weeks. A standard serial root canal preparation technique was performed in the molar of one side, whilst the opposite side was the control group. Rats were randomly divided into three experimental groups (n = 8), according to the diameter of apical enlargement during root canal preparation: K-files size 20 (EG1), size 25 (EG2) and size 30 (EG3). Each animal was its own positive control, because the opposite arch remained untreated. Root canals were filled with a standard technique. After 3 weeks, the animals were euthanized. The main outcome of apical periodontitis healing was evaluated radiographically (mm 2 ) and histologically (ordinal scores of inflammation) using a HE staining technique. The measurement of effect was obtained between the three experimental groups by carrying out generalized estimating equations, with Poisson regression with robust variance, pairing each experimental group with its respective control group within animals, adjusted for the mean within animal differences, with α = 5%. The mean and standard deviations of radiographic apical periodontitis size (mm 2 ) and intensity of histological inflammatory scores were, respectively: EG1 (0.44 ± 0.27; 2.25 ± 0.46), EG2 (0.33 ± 0.10; 2.50 ± 0.53) and EG3 (0.22 ± 0.08; 2.63 ± 0.74). After 3 weeks, a significantly more favourable radiographic repair was observed when larger apical enlargement was performed (EG3), compared to EG1 and EG2 (P = 0.001). All experimental groups were associated with a significant difference on the radiographic and histological healing of apical periodontitis compared with its respective control group. Under the experimental conditions of this study, a larger apical enlargement protocol favoured a more rapid radiographic repair of apical periodontitis in rats after a 3-week follow-up. © 2018 International Endodontic Journal. Published by John Wiley & Sons Ltd.

A novel suture technique using the FasT-Fix combined with Ultrabraid for pullout repair of the medial meniscus posterior root tear.

PubMed

Fujii, Masataka; Furumatsu, Takayuki; Kodama, Yuya; Miyazawa, Shinichi; Hino, Tomohito; Kamatsuki, Yusuke; Yamada, Kazuki; Ozaki, Toshifumi

2017-05-01

Medial meniscus posterior root has an important role in the maintenance of knee articular cartilage. Although pullout repair of the medial meniscus posterior root tear has become a gold standard, it has several difficulties for suturing. We have developed a modified Mason-Allen suture technique using the FasT-Fix all-inside suture device combined with Ultrabraid. The present suture technique allows a strong grasping of the medial meniscus posterior horn for arthroscopic pullout repair.

Water distribution at the root-soil interface: is there more water next to roots?

NASA Astrophysics Data System (ADS)

Carminati, A.; Moradi, A.; Oswald, S.; Vetterlein, D.; Weller, U.; Vogel, H.-J.

2009-04-01

Plants are big water movers and have a significant impact on soil water dynamics as well as on the global water cycle. Despite the relevance of root water uptake in terrestrial ecology, the movement of water from soil to roots still presents important open questions, e.g the following two. Which are the properties of the soil near the roots? And what effect do these properties have on soil plant water relations? Most models are based on brute-force spatial averaging of soil properties and assume that the bulk soil has the same properties as the rhizosphere. However, there is evidence in the literature that the rhizosphere has specific properties that may affect water and nutrient uptake (Young 1995, Gregory 2007). In order to investigate the rhizosphere hydraulic properties and their effect on soil plant water relations, we used neutron radiography and neutron tomography to image the water content distribution in soils during plant transpiration. Rectangular (quasi-2D) and cylindrical containers were filled with sandy soil and planted with lupins (Lupinus albus). Three weeks after planting, the samples were equilibrated at water potentials of -10 and 30 hPa and have been imaged for 5 days at intervals of 6 hours. At day 5 the samples were irrigated again via capillary rise and the water distribution was monitored for 4 more days. During the first day of the drying period, regions of water depletion formed around the central part of the tap root where first order laterals were present. As the soil dried up, the picture changed: instead of less water around the roots, as commonly supposed by models, we observed that more water was present around the lateral roots. Interestingly, these regions during drying were retaining high water content, but after irrigation remained markedly drier than the bulk soil. Our hypothesis is that high water content near roots during drying and lower water content during rewetting are explained by the presence of bio-polymers exuded by roots forming a hydrogel that consists of up to 99% water at very negative water potentials (Read et al. 1999). Thanks to its high water holding capacity, this hydrogel maintains a continuous hydraulic pathway across soil and roots for an extended period of time during drying. During rewetting it adversely affects water redistribution, like a storage that needs time to fill up again. These data show for the first time in situ the potential role of mucilage in controlling water dynamics in the rhizosphere and consequences for plant water extraction. Gregory P J, Roots, rhizosphere and soil: the route to a better understanding of soil science? European Journal of Soil Science, 57: 2-12, 2006. Read D P, Gregory P J, and Bell A E. Physical properties of axenic maize root mucilage. Plant and Soil, 211: 87-91, 1999. Young I M. Variation in moisture contents between bulk soil and the rhizosheath of wheat. New Phytologist, 130: 135-139, 1995.

A comparison of three rotary systems and hand instrumentation technique for the elimination of Enterococcus faecalis from the root canal.

PubMed

Gorduysus, Melahat; Nagas, Emre; Torun, Ozgur Yildirim; Gorduysus, Omer

2011-12-01

The aim of this study was to compare the in vitro reduction of a bacterial population in a root canal by mechanical instrumentation using three rotary systems and hand instrumentation technique. The root canals contaminated with a suspension of Enterococcus faecalis were instrumented using ProTaper, K3, HeroShaper and K-file hand instrumentation technique. Later the root canals were sampled. After serial dilutions, samples were incubated in culture media for 24 h. Bacterial colonies were counted and the results were given as number of colony-forming units per millilitre. The results showed that all the canal instrumentation systems reduced the number of bacterial cells in the root canals. Statistically, ProTaper instruments were more effective in reducing the number of bacteria than the other rotary files or hand instruments. © 2010 The Authors. Australian Endodontic Journal © 2010 Australian Society of Endodontology.

Mineral trioxide aggregate repair of a perforating internal resorption in a mandibular molar.

PubMed

Meire, Maarten; De Moor, Roeland

2008-02-01

Internal resorption is a rare condition in permanent teeth that poses difficulties for treatment. The challenge is complicated further if the resorption extends beyond the confines of the root. This article describes treatment of a perforating internal resorption in the mesial root of a second lower molar, with adjacent destruction of the alveolar bone. After cleaning the root canal space and the resorption lacuna by mechanical instrumentation, irrigation, and interim calcium hydroxide dressing, the defect was filled with mineral trioxide aggregate, and the canals were obturated conventionally with gutta percha and epoxy resin sealer. At a 2-year follow-up examination, no clinical abnormalities were found, and complete resolution of the alveolar bone lesion and establishment of a new periodontal ligament were observed.

A comparison of the relative efficacies of four hand and rotary instrumentation techniques during endodontic retreatment.

PubMed

Imura, N; Kato, A S; Hata, G I; Uemura, M; Toda, T; Weine, F

2000-07-01

The purpose of this study was to quantify the amount of remaining gutta-percha/scaler on the walls of root canals when two engine-driven instruments (Quantec and ProFile) and two hand instruments (K-file and Hedström file) were used to remove these materials. The amount of apically extruded debris and the time required for treatment were also recorded. One hundred extracted mandibular premolars were prepared using a modified step-back, flare technique and obturated with the lateral condensation technique. After repreparation with the test instruments, the specimens were cut transversally at the cervical, middle and apical thirds with steel discs and the three sections were split longitudinally. The amount of residual debris on the canal walls in each section was examined using a stereomicroscope. In all groups the cervical and middle thirds showed no debris. In the apical third, obturating material was observed in some specimens. No statistically significant difference was found between the two groups for incidence of debris, although the Hedström group showed a greater number of samples with remaining gutta-percha/sealer. When analysing dirty specimens only, there was a statistically significant difference between the four groups (P < 0.01) with the Hedström group having significantly less length of canal wall with remaining obturation material than the Quantec group. There was no significant difference amongst the groups for weight of extruded debris. However, there was a significant difference amongst the groups for mean treatment time with the Hedström file group requiring significantly less time than the Quantec group (P < 0.001); no significant differences were found between the other groups. Six instruments fractured in the Quantec group, four in the ProFile group, two in the Hedström group and two in the K-type group. The results showed that overall, all instruments may leave filling material inside the root canal. During retreatment there is a risk of instrument breakage, especially rotary instruments.

Efficacy of statin delivery as an adjunct to scaling and root planing in the treatment of chronic periodontitis: A meta-analysis.

PubMed

Akram, Zohaib; Vohra, Fahim; Javed, Fawad

2018-05-01

The action of statins in stimulating bone formation and having other pleiotropic effects, such as anti-inflammatory and immunomodulatory effects, has justified their use as an adjunct to scaling and root planing (SRP) in the treatment of chronic periodontitis (CP). The aim of the present study was to evaluate the efficacy of statin delivery as an adjunct to SRP in the treatment of CP. Electronic searches were conducted using the following databases: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Cochrane Oral Health Group Trials Register, up until July 2017. The primary outcome was probing depth (PD), while the secondary outcomes were changes in clinical attachment level (CAL) and bone defect (BD) fill. Eleven studies were included, and all showed significant PD reduction, CAL gain, and BD fill with adjunctive statin delivery compared to SRP alone. The meta-analysis showed significant improvement in periodontal parameters for atorvastatin (PD: weighted mean difference [WMD] = -1.84, -2.56 to -1.12, P < .001; CAL: WMD = -2.31, -3.58 to -1.03, P < .001; BD fill: WMD = 2.66, -3.92 to -1.39, P < .001), simvastatin (PD: WMD = -1.91, -2.27 to -1.55, P < .001; CAL: WMD = -1.91, -2.27 to -1.55, P = .001; BD: WMD = -1.52, -2.20 to -0.85, P < .001), and rosuvastatin (PD: WMD = -0.94, -1.32 to -0.55, P < .001; CAL: WMD = -1.00, -1.41 to -0.60, P < .001; BD fill: WMD = -1.30, -1.80 to -0.79, P < .001). Adjunctive statin delivery appears to be effective in reducing PD, CAL gain, and BD fill in CP, and therefore, these drugs could be a promising therapeutic option for periodontal regeneration in future. © 2017 John Wiley & Sons Australia, Ltd.

Can differences in root responses to soil drying and compaction explain differences in performance of trees growing on landfill sites?

PubMed

Liang, Jiansheng; Zhang, Jianhua; Chan, Gilbert Y. S.; Wong, M. H.

1999-07-01

Two tropical woody species, Acacia confusa Merrill and Litsea glutinosa (Lour.) C.B. Robinson, were grown under controlled conditions in PVC pipes filled with John Innes No. 2 soil. To investigate root distribution, physiological characteristics and hydraulic conductivity, four soil treatments were imposed-well-watered and noncompacted (control), well-watered and compacted; unwatered and noncompacted, and unwatered and compacted. In L. glutinosa, rooting depth and root elongation were severely restricted when soil bulk density increased from around 1.12 to 1.62 g cm(-3), whereas soil compaction had little effect on these parameters in A. confusa. As soil drying progressed, root water potential and osmotic potential declined more slowly in L. glutinosa than in A. confusa. Both the soil drying and compaction treatments significantly stimulated the accumulation of root abscisic acid (ABA) in both species. Soil drying damaged the root cell membrane of A. confusa, but had little influence on the root cell membrane of L. glutinosa. Soil drying had a greater effect on root hydraulic conductivity (L(p)) in L. glutinosa than in A. confusa, whereas the effect of soil compaction on L(p) was less in L. glutinosa than in A. confusa. Soil drying enhanced the effects of soil compaction on root L(p). We conclude that soil drying and compaction have large species-specific effects on the distribution, growth and physiology of roots. The relationships of these root properties to the species' ability to tolerate unfavorable soil conditions were examined.

Phenotyping: Using Machine Learning for Improved Pairwise Genotype Classification Based on Root Traits

PubMed Central

Zhao, Jiangsan; Bodner, Gernot; Rewald, Boris

2016-01-01

Phenotyping local crop cultivars is becoming more and more important, as they are an important genetic source for breeding – especially in regard to inherent root system architectures. Machine learning algorithms are promising tools to assist in the analysis of complex data sets; novel approaches are need to apply them on root phenotyping data of mature plants. A greenhouse experiment was conducted in large, sand-filled columns to differentiate 16 European Pisum sativum cultivars based on 36 manually derived root traits. Through combining random forest and support vector machine models, machine learning algorithms were successfully used for unbiased identification of most distinguishing root traits and subsequent pairwise cultivar differentiation. Up to 86% of pea cultivar pairs could be distinguished based on top five important root traits (Timp5) – Timp5 differed widely between cultivar pairs. Selecting top important root traits (Timp) provided a significant improved classification compared to using all available traits or randomly selected trait sets. The most frequent Timp of mature pea cultivars was total surface area of lateral roots originating from tap root segments at 0–5 cm depth. The high classification rate implies that culturing did not lead to a major loss of variability in root system architecture in the studied pea cultivars. Our results illustrate the potential of machine learning approaches for unbiased (root) trait selection and cultivar classification based on rather small, complex phenotypic data sets derived from pot experiments. Powerful statistical approaches are essential to make use of the increasing amount of (root) phenotyping information, integrating the complex trait sets describing crop cultivars. PMID:27999587

Cone-beam computed tomography in the assessment of periapical lesions in endodontically treated teeth

PubMed Central

Gambarini, Gianluca; Piasecki, Lucila; Miccoli, Gabriele; Gaimari, Gianfranco; Nardo, Dario Di; Testarelli, Luca

2018-01-01

Objective: This study aimed to evaluate the relationship between the quality of the coronal restoration and the root canal filling on the periapical status of endodontically treated teeth using CBCT. Materials and Methods: CBCT data were obtained from the records of patients who deny any dental treatment in the 2 years prior to the CBCT examination. CBCT images (90 kVp and 7 mA, exposure time of 23 s, and a voxel size of 0.2 mm, with a field of view of 13 cm × 13 cm) of 1011 endodontically treated teeth were observed. A score was given to the quality of the root filling and the quality of the coronal restoration. Statistical Analysis Used: Data were statistically analyzed to correlate the periapical status with gender, dental group. and quality of endodontic treatment and restoration (Chi-square test with a significance level of P < 0.001). Results: Absence of periapical periodontitis was found in 54.9% of the cases. The periapical outcome was not related to gender or dental group (P > 0.05). A statistically significant factor (Chi-square test, P < 0.0001) resulted when different qualities of sealing were compared. Conclusions: CBCT showed that high-quality root canal treatments followed by an adequate coronal sealing restoration avoid the presence of periapical periodontitis in time. PMID:29657539

New method for propagating the square root covariance matrix in triangular form. [using Kalman-Bucy filter

NASA Technical Reports Server (NTRS)

Choe, C. Y.; Tapley, B. D.

1975-01-01

A method proposed by Potter of applying the Kalman-Bucy filter to the problem of estimating the state of a dynamic system is described, in which the square root of the state error covariance matrix is used to process the observations. A new technique which propagates the covariance square root matrix in lower triangular form is given for the discrete observation case. The technique is faster than previously proposed algorithms and is well-adapted for use with the Carlson square root measurement algorithm.

The effect of the heights and thicknesses of the remaining root segments on buccal bone resorption in the socket-shield technique: An experimental study in dogs.

PubMed

Tan, Zhen; Kang, Jian; Liu, Wenjia; Wang, Hang

2018-06-01

To date only a few studies have been done on the use of the socket-shield technique for preserving the resorption of the buccal bone in aesthetically sensitive sites. Besides, there have been no further studies on the effect of the heights and thicknesses of the remaining root segments on buccal bone resorption when using this method. The aim of this study was to evaluate the effect of different heights and thicknesses of the remaining root segments on bone resorption in the socket-shield technique. Four healthy female beagle dogs were used in this study. The third premolar (P3) and the fourth premolar (P4) on both sides of the mandible were hemisected in the buccal-lingual direction, and the clinical crown of the distal root was beheaded. In the experimental groups, the roots were worn down in the apical direction until they were located at the buccal crestal level (Group A) or 1 mm higher than that level (Group B). In the control group, the distal root segments were extracted. Then, implant placement was performed into the distal root. After 3 months of healing, the specimens were prepared for histological diagnosis. There was no difference between Group A and Group B when using the socket-shield technique, but the results of both groups were better than those of the control group. The height of the root segments has little effect on the bone absorption of alveolar bone, while the bone absorption was strongly influenced by the thickness of the root segments. More precisely, the absorption may decrease if the thickness of the root fragment increases, when the thickness of the root plate is in the 0.5-1.5 mm range. © 2018 Wiley Periodicals, Inc.

Semiconductor laser irradiation improves root canal sealing during routine root canal therapy

PubMed Central

Hu, Xingxue; Wang, Dashan; Cui, Ting; Yao, Ruyong

2017-01-01

Objective To evaluate the effect of semiconductor laser irradiation on root canal sealing after routine root canal therapy (RCT). Methods Sixty freshly extracted single-rooted human teeth were randomly divided into six groups (n = 10). The anatomic crowns were sectioned at the cementoenamel junction and the remaining roots were prepared endodontically with conventional RCT methods. Groups A and B were irradiated with semiconductor laser at 1W for 20 seconds; Groups C and D were ultrasonically rinsed for 60 seconds as positive control groups; Groups E and F without treatment of root canal prior to RCT as negative control groups. Root canal sealing of Groups A, C and E were evaluated by measurements of apical microleakage. The teeth from Groups B, D and F were sectioned, and the micro-structures were examined with scanning electron microscopy (SEM). One way ANOVA and LSD-t test were used for statistical analysis (α = .05). Results The apical sealing of both the laser irradiated group and the ultrasonic irrigated group were significantly different from the control group (p<0.5). There was no significant difference between the laser irradiated group and the ultrasonic irrigated group (p>0.5). SEM observation showed that most of the dentinal tubules in the laser irradiation group melted, narrowed or closed, while most of the dentinal tubules in the ultrasonic irrigation group were filled with tooth paste. Conclusion The application of semiconductor laser prior to root canal obturation increases the apical sealing of the roots treated. PMID:28957407

Tolerance to high soil temperature in foxtail millet (Setaria italica L.) is related to shoot and root growth and metabolism.

PubMed

Aidoo, Moses Kwame; Bdolach, Eyal; Fait, Aaron; Lazarovitch, Naftali; Rachmilevitch, Shimon

2016-09-01

Roots play important roles in regulating whole-plant carbon and water relations in response to extreme soil temperature. Three foxtail millet (Setaria italica L.) lines (448-Ames 21521, 463-P1391643 and 523-P1219619) were subjected to two different soil temperatures (28 and 38 °C). The gas exchange, chlorophyll fluorescence, root morphology and central metabolism of leaves and roots were studied at the grain-filling stage. High soil temperature (38 °C) significantly influenced the shoot transpiration, stomatal conductance, photosynthesis, root growth and metabolism of all lines. The root length and area were significantly reduced in lines 448 and 463 in response to the stress, while only a small non-specific reduction was observed in line 523 in response to the treatment. The shift of root metabolites in response to high soil temperature was also genotype specific. In response to high soil temperature, glutamate, proline and pyroglutamate were reduced in line 448, and alanine, aspartate, glycine, pyroglutamate, serine, threonine and valine were accumulated in line 463. In the roots of line 523, serine, threonine, valine, isomaltose, maltose, raffinose, malate and itaconate were accumulated. Root tolerance to high soil temperature was evident in line 523, in its roots growth potential, lower photosynthesis and stomatal conductance rates, and effective utilization and assimilation of membrane carbon and nitrogen, coupled with the accumulation of protective metabolites. Copyright © 2016. Published by Elsevier Masson SAS.

Comparison of alternative image reformatting techniques in micro-computed tomography and tooth clearing for detailed canal morphology.

PubMed

Lee, Ki-Wook; Kim, Yeun; Perinpanayagam, Hiran; Lee, Jong-Ki; Yoo, Yeon-Jee; Lim, Sang-Min; Chang, Seok Woo; Ha, Byung-Hyun; Zhu, Qiang; Kum, Kee-Yeon

2014-03-01

Micro-computed tomography (MCT) shows detailed root canal morphology that is not seen with traditional tooth clearing. However, alternative image reformatting techniques in MCT involving 2-dimensional (2D) minimum intensity projection (MinIP) and 3-dimensional (3D) volume-rendering reconstruction have not been directly compared with clearing. The aim was to compare alternative image reformatting techniques in MCT with tooth clearing on the mesiobuccal (MB) root of maxillary first molars. Eighteen maxillary first molar MB roots were scanned, and 2D MinIP and 3D volume-rendered images were reconstructed. Subsequently, the same MB roots were processed by traditional tooth clearing. Images from 2D, 3D, 2D + 3D, and clearing techniques were assessed by 4 endodontists to classify canal configuration and to identify fine anatomic structures such as accessory canals, intercanal communications, and loops. All image reformatting techniques in MCT showed detailed configurations and numerous fine structures, such that none were classified as simple type I or II canals; several were classified as types III and IV according to Weine classification or types IV, V, and VI according to Vertucci; and most were nonclassifiable because of their complexity. The clearing images showed less detail, few fine structures, and numerous type I canals. Classification of canal configuration was in 100% intraobserver agreement for all 18 roots visualized by any of the image reformatting techniques in MCT but for only 4 roots (22.2%) classified according to Weine and 6 (33.3%) classified according to Vertucci, when using the clearing technique. The combination of 2D MinIP and 3D volume-rendered images showed the most detailed canal morphology and fine anatomic structures. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Tunneling procedure for root coverage using acellular dermal matrix: a case series.

PubMed

Modaressi, Marmar; Wang, Hom-Lay

2009-08-01

This study was designed to demonstrate the use of the relatively novel tunneling technique for root coverage with acellular dermal matrix (ADM) to treat Miller Class I and II gingival recession defects. Five subjects with two to five adjacent buccal gingival recession defects were treated with ADM using the tunneling technique for root coverage. A calibrated, blinded examiner measured clinical parameters, including probing depth, clinical attachment level, width of keratinized tissue, recession depth, recession width at 1 mm apical to the cementoenamel junction, gingival tissue thickness at 1 mm and 3 mm apical to the gingival margin, Plaque Index, Gingival Index, and Wound Healing Index, at different time intervals. Patient discomfort was recorded 14 days postoperatively, and an overall quality assessment was recorded 180 days postoperatively. Results showed an average of 61% defect coverage (equal to 93.5% root coverage), and a 0.15-mm gain in tissue thickness was achieved 1 year postoperatively. This suggested that root coverage with ADM using the tunneling technique can be a viable alternative to traditional techniques, especially for multiple recession defects in maxillary premolar and anterior teeth.

Removal efficiency of calcium hydroxide dressing from the root canal without chemically active adjuvant.

PubMed

Maalouf, Lara; Zogheib, Carla; Naaman, Alfred

2013-03-01

Compare the efficiency in removing two calcium hydroxide [Ca(OH)2] preparations from root canal and apical third using single use syringe, ultrasonics and RinsEndo((®)) with saline solution. One hundred and eighty human singlerooted teeth were instrumented using ProTaper((®)) rotary system, divided into two groups according to Ca(OH)2 filling. A: Powder mixed with water, B: Pulpdent((®)). Each group was divided into three subgroups for the irrigation: A1, B1: Single use syringe; A2, B2: Ultrasonics; A3, B3: RinsEndo((®)). Teeth were split longitudinally, photographed and imported into Adobe Photoshop. The percentage ratios of Ca(OH)2 remaining in the canal and in the apical third were calculated. Data were statistically analyzed using 'ANOVA two-way' and 'univariate tests'. (a) Remnants of medicament were found in all teeth, (b) no statistically significant difference in the elimination of both Ca(OH)2 from the entire canal (p = 0.436), however, mixed powder was better eliminated from the apical third (p = 0.005), (c) no statistically significant difference among the irrigation techniques in the whole canal (p = 0.608), though, RinsEndo((®)) and ultrasonics were the most effective in cleaning the apical third (p = 0.032) when mixed powder was used. None of the techniques removed completely Ca(OH)2 from the canal. In the apical third, RinsEndo((®)) and ultrasonics were the most effective when mixed powder was used. Ca(OH)2, the most commonly used intracanal dressing, should be completely eliminated before the obturation to assure a good endodontic sealing. Based on the results of this study, RinsEndo((®)) and ultrasonics were the most effective in removal of Ca(OH)2 especially the powder mixed with water presentation.

Amplification of pressure waves in laser-assisted endodontics with synchronized delivery of Er:YAG laser pulses.

PubMed

Lukač, Nejc; Jezeršek, Matija

2018-05-01

When attempting to clean surfaces of dental root canals with laser-induced cavitation bubbles, the resulting cavitation oscillations are significantly prolonged due to friction on the cavity walls and other factors. Consequently, the collapses are less intense and the shock waves that are usually emitted following a bubble's collapse are diminished or not present at all. A new technique of synchronized laser-pulse delivery intended to enhance the emission of shock waves from collapsed bubbles in fluid-filled endodontic canals is reported. A laser beam deflection probe, a high-speed camera, and shadow photography were used to characterize the induced photoacoustic phenomena during synchronized delivery of Er:YAG laser pulses in a confined volume of water. A shock wave enhancing technique was employed which consists of delivering a second laser pulse at a delay with regard to the first cavitation bubble-forming laser pulse. Influence of the delay between the first and second laser pulses on the generation of pressure and shock waves during the first bubble's collapse was measured for different laser pulse energies and cavity volumes. Results show that the optimal delay between the two laser pulses is strongly correlated with the cavitation bubble's oscillation period. Under optimal synchronization conditions, the growth of the second cavitation bubble was observed to accelerate the collapse of the first cavitation bubble, leading to a violent collapse, during which shock waves are emitted. Additionally, shock waves created by the accelerated collapse of the primary cavitation bubble and as well of the accompanying smaller secondary bubbles near the cavity walls were observed. The reported phenomena may have applications in improved laser cleaning of surfaces during laser-assisted dental root canal treatments.

Evaluation of smear layer removal and marginal adaptation of root canal sealer after final irrigation using ethylenediaminetetraacetic, peracetic, and etidronic acids with different concentrations.

PubMed

Ulusoy, Özgür İlke; Zeyrek, Salev; Çelik, Bülent

2017-07-01

The purpose of this study was to investigate the effects of different irrigation solutions on the smear layer removal and marginal adaptation of a resin-based sealer to root canal dentine. A total of 152 instrumented roots were irrigated with the following irrigants: 9,18% etidronic acid (HEBP), 0.5, 1,2% peracetic acid (PAA), 17% ethylenediaminetetraacetic acid (EDTA), saline. The amount of smear layer was evaluated using scanning electron microscope (SEM) in seventy root samples. Eighty-two roots were filled with AH Plus and gutta-percha. Slices obtained from apical third of each specimen were viewed with SEM to assess marginal adaptation. Use of 9% and 18% HEBP resulted in more efficient smear layer removal in the apical third than the other chelators (p < 0.05). Higher smear layer scores in the coronal and middle thirds were obtained from 0.5%, 1% PAA groups. Regarding marginal adaptation, 18% HEBP group showed the lowest gap size values (p < 0.05), and better marginal adaptation. Etidronic acid is a promising candidate for final irrigation of root canals. © 2017 Wiley Periodicals, Inc.

Microsurgical removal of epidermal and cortical cells: evidence that the gravitropic signal moves through the outer cell layers in primary roots of maize

NASA Technical Reports Server (NTRS)

Yang, R. L.; Evans, M. L.; Moore, R.

1990-01-01

There is general agreement that during root gravitropism some sort of growth-modifying signal moves from the cap to the elongation zone and that this signal ultimately induces the curvature that leads to reorientation of the root. However, there is disagreement regarding both the nature of the signal and the pathway of its movement from the root cap to the elongation zone. We examined the pathway of movement by testing gravitropism in primary roots of maize (Zea mays L.) from which narrow (0.5 mm) rings of epidermal and cortical tissue were surgically removed from various positions within the elongation zone. When roots were girdled in the apical part of the elongation zone gravitropic curvature occurred apical to the girdle but not basal to the girdle. Filling the girdle with agar allowed curvature basal to the girdle to occur. Shallow girdles, in which only two or three cell layers (epidermis plus one or two cortical cell layers) were removed, prevented or greatly delayed gravitropic curvature basal to the girdle. The results indicate that the gravitropic signal moves basipetally through the outermost cell layers, perhaps through the epidermis itself.

Pre- and Postoperative Imaging of the Aortic Root

PubMed Central

Chan, Frandics P.; Mitchell, R. Scott; Miller, D. Craig; Fleischmann, Dominik

2016-01-01

Three-dimensional datasets acquired using computed tomography and magnetic resonance imaging are ideally suited for characterization of the aortic root. These modalities offer different advantages and limitations, which must be weighed according to the clinical context. This article provides an overview of current aortic root imaging, highlighting normal anatomy, pathologic conditions, imaging techniques, measurement thresholds, relevant surgical procedures, postoperative complications and potential imaging pitfalls. Patients with a range of clinical conditions are predisposed to aortic root disease, including Marfan syndrome, bicuspid aortic valve, vascular Ehlers-Danlos syndrome, and Loeys-Dietz syndrome. Various surgical techniques may be used to repair the aortic root, including placement of a composite valve graft, such as the Bentall and Cabrol procedures; placement of an aortic root graft with preservation of the native valve, such as the Yacoub and David techniques; and implantation of a biologic graft, such as a homograft, autograft, or xenograft. Potential imaging pitfalls in the postoperative period include mimickers of pathologic processes such as felt pledgets, graft folds, and nonabsorbable hemostatic agents. Postoperative complications that may be encountered include pseudoaneurysms, infection, and dehiscence. Radiologists should be familiar with normal aortic root anatomy, surgical procedures, and postoperative complications, to accurately interpret pre- and postoperative imaging performed for evaluation of the aortic root. Online supplemental material is available for this article. ©RSNA, 2015 PMID:26761529

The effect of partially exposed connective tissue graft on root-coverage outcomes: a systematic review and meta-analysis.

PubMed

Dodge, Austin; Garcia, Jeffrey; Luepke, Paul; Lai, Yu-Lin; Kassab, Moawia; Lin, Guo-Hao

2018-04-01

The aim of this systematic review was to compare the root-coverage outcomes of using a partially exposed connective tissue graft (CTG) technique with a fully covered CTG technique for root coverage. An electronic search up to February 28 th , 2017, was performed to identify human clinical studies with data comparing outcomes of root coverage using CTG, with and without a partially exposed graft. Five clinical studies were selected for inclusion in this review. For each study, the gain of keratinized gingiva, reduction of recession depth, number of surgical sites achieving complete root coverage, percentage of root coverage, gain of tissue thickness, and changes of probing depth and clinical attachment level were recorded. Meta-analysis for the comparison of complete root coverage between the two techniques presented no statistically significant differences. A statistically significant gain of keratinized tissue in favor of the sites with an exposed CTG and a tendency of greater reduction in recession depth were seen at the sites with a fully covered CTG. Based on the results, the use of a partially exposed CTG in root-coverage procedures could achieve greater gain in keratinized gingiva, while a fully covered CTG might be indicated for procedures aiming to reduce recession depth. © 2018 Eur J Oral Sci.