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Sample records for root dentine irradiated

  1. The bactericidal effect of Ho:YAG laser irradiation within contaminated root dentinal samples.

    PubMed

    Gouw-Soares, S; Gutknecht, N; Conrads, G; Lampert, F; Matson, E; Eduardo, C P

    2000-04-01

    This in vitro study investigates the bactericidal effect of pulsed Ho:YAG laser irradiation in the depth of contaminated dentin specimens. Previous studies have shown the effectiveness of laser irradiation in bacterial reduction of infected root canal. Root dentin of bovine teeth were sliced longitudinally in 180 samples of 100 microm, 300 microm, and 500 microm thickness, sterilized, dried, and inoculated on one side, with 1 microL of Enterococcus faecalis suspension. The opposite side's were irradiated four times for 5 seconds each with Ho:YAG laser irradiation, a wavelength of 2.10 microm, using four different energy settings: 1 W/5 Hz; 1 W/10 Hz; 1.5 W/5 Hz, and 2.0 W/5 Hz through a 320-microm quartz fiber at an angle of approximately 5 degrees. In addition, two control groups were investigated, the first was inoculated and not submitted to any treatment, the second was inoculated and treated with NaOCl and H2O2. The remaining bacteria from each dentin sample in a transport media were removed by vibration, serially diluted, and plated out on culture dishes selective for Enterococcus faecalis. When compared with the untreated control group or even with the group treated with NaOCl plus H2O2, counting of colonies forming units (CFU) from the laser-treated samples revealed a high significant bacterial elimination with a maximum of 98.46% and a minimum of 83.65%. Our findings demonstrate a significant decrease of the bacterial population in depth, suggesting that the Ho:YAG laser irradiation could be effective to eliminate the microorganisms harbored within dentin or contaminated canals.

  2. Analysis of permeability and morphology of root canal dentin after Er,Cr:YSGG laser irradiation.

    PubMed

    Silva, Anna Cristina Biella; Guglielmi, Camila; Meneguzzo, Daiane Thais; Aranha, Ana Cecília Corrêa; Bombana, Antônio Carlos; de Paula Eduardo, Carlos

    2010-02-01

    The aim of this study was to evaluate the morphology and permeability of root canal walls irradiated with Er,Cr:YSGG laser after conventional endodontic treatment. Laser irradiation can be used for dentinal tubule exposure, smear layer removal, and disinfection. Another potential, interesting application is as an adjunct to endodontic treatment, especially in the intracanal medication phase. Fifty-two single-rooted teeth had their crowns sectioned at the cementoenamel junction and were randomly divided into four groups (n = 13): G1: conventional preparation (CP) + irrigation with EDTA-T + rhodamine B dye solution associated with NDP (dexamethasone phosphate, paramonochlorophenol, polyethylenoglycol) (Rhod-NDP); G2: CP + EDTA-T + Er,Cr:YSGG laser irradiation 0.75 W + Rhod-NDP; G3: CP + EDTA-T + Er,Cr:YSGG 1.5 W + Rhod-NDP; G4: CP + EDTA-T + Er,Cr:YSGG 2.5 W + Rhod-NDP. For the permeability analysis (n = 9), teeth were transversely cut and two slices of each third were selected. The images were analyzed by ImageLab software (Softium Informática Ltda., São Paulo, SP, Brazil). Additional samples (n = 4) were examined by scanning electron microscopy. Data were analyzed statistically using the Kruskal-Wallis and Student-Newman-Keuls tests for the following areas: apical third (H = 23.4651): G1 (14.25)(a), G2 (17.66)(ab), G3 (26.50)(b), G4 (39.58)(c); medium (H = 23.1611): G1 (14.16)(a), G2 (16.66)(ab), G3 (28.83)(b), G4 (38.33)(b); and cervical (H = 32.4810): G1 (9.66)(a), G2 (20. 00)(ab), G3 (27.00)(b), G4 (41.33)(c), (p < 0.01). Despite the irregular aspect of laser irradiation along the canal walls, the parameters of 1.5 W and 2.5 W allowed morphologic modifications that increased dentinal permeability. Irradiation with Er,Cr:YSGG laser could be effective in endodontic treatment for increasing dentinal permeability.

  3. Comparison of dentin root canal permeability and morphology after irradiation with Nd:YAG, Er:YAG, and diode lasers.

    PubMed

    Esteves-Oliveira, Marcella; de Guglielmi, Camila A B; Ramalho, Karen Müller; Arana-Chavez, Victor E; de Eduardo, Carlos Paula

    2010-09-01

    The aim of this study was to compare the effects of Nd:YAG, Er:YAG, and diode lasers on the morphology and permeability of root canal walls. The three laser wavelengths mentioned interact differently with dentin and therefore it is possible that the permeability changes caused will determine different indications during endodontic treatment. Twenty-eight human single-rooted teeth were instrumented up to ISO 40 and divided into four groups: group C, control (GC), non-laser irradiated; group N (GN), irradiated with Nd:YAG laser; group E (GE), with Er:YAG laser and group D (GD) with diode laser. After that, the roots were filled with a 2% methylene blue dye, divided into two halves and then photographed. The images were analyzed using Image J software and the percentage of dye penetration in the cervical, middle, and apical root thirds were calculated. Additional scanning electron microscopy (SEM) analyses were also performed. The analysis of variance (ANOVA) showed significant permeability differences between all groups in the middle and cervical thirds (p < 0.05). The Tukey test showed that in the cervical third, GN presented means of dye penetration statistically significantly lower than all of the other groups. In the middle third, GE and GD showed statistically higher dye penetration means than GC and GN. SEM analysis showed melted surfaces for GN, clean wall surfaces with open dentinal tubules for GE, and mostly obliterated dentinal tubules for GD. Er:YAG (2,094 nm) laser and diode laser (808 nm) root canal irradiation increase dentinal permeability and Nd:YAG (1,064 nm) laser decreases dentin permeability, within the studied parameters.

  4. Single session of Nd:YAG laser intracanal irradiation neutralizes endotoxin in dental root dentin

    NASA Astrophysics Data System (ADS)

    Archilla, José R. F.; Moreira, Maria S. N. A.; Miyagi, Sueli P. H.; Bombana, Antônio C.; Gutknecht, Norbert; Marques, Márcia M.

    2012-11-01

    Endotoxins released in the dental root by Gram-negative microorganisms can be neutralized by calcium hydroxide, when this medication is applied inside the root canal for at least seven days. However, several clinical situations demand faster root canal decontamination. Thus, for faster endotoxin neutralization, endodontists are seeking additional treatments. The in vitro study tested whether or not intracanal Nd:YAG laser irradiation would be able to neutralize endotoxin within the human dental root canal in a single session. Twenty-four human teeth with one root were mounted between two chambers. After conventional endodontic treatment, root canals were contaminated with Escherichia coli endotoxin. Then they were irradiated or not (controls) in contact mode with an Nd:YAG laser (1.5 W, 15 Hz, 100 mJ and pulse fluency of 124 J/cm2). The endotoxin activity was measured using the limulus lysate technique and data were statistically compared (p≤0.05). The concentration of active endotoxin measured in the negative control group was significantly lower than that of the positive control group (p=0.04). The concentrations of endotoxin in both irradiated groups were significantly lower than that of the positive control group (p=0.027) and similar to that of negative control group (p=0.20). A single session of intracanal Nd:YAG laser irradiation is able to neutralize endotoxin in the dental root tissues.

  5. Single session of Nd:YAG laser intracanal irradiation neutralizes endotoxin in dental root dentin.

    PubMed

    Archilla, José R F; Moreira, Maria S N A; Miyagi, Sueli P H; Bombana, Antônio C; Gutknecht, Norbert; Marques, Márcia M

    2012-11-01

    Endotoxins released in the dental root by Gram-negative microorganisms can be neutralized by calcium hydroxide, when this medication is applied inside the root canal for at least seven days. However, several clinical situations demand faster root canal decontamination. Thus, for faster endotoxin neutralization, endodontists are seeking additional treatments. The in vitro study tested whether or not intracanal Nd:YAG laser irradiation would be able to neutralize endotoxin within the human dental root canal in a single session. Twenty-four human teeth with one root were mounted between two chambers. After conventional endodontic treatment, root canals were contaminated with Escherichia coli endotoxin. Then they were irradiated or not (controls) in contact mode with an Nd:YAG laser (1.5 W, 15 Hz, 100 mJ and pulse fluency of 124  J/cm2). The endotoxin activity was measured using the limulus lysate technique and data were statistically compared (p≤0.05). The concentration of active endotoxin measured in the negative control group was significantly lower than that of the positive control group (p=0.04). The concentrations of endotoxin in both irradiated groups were significantly lower than that of the positive control group (p=0.027) and similar to that of negative control group (p=0.20). A single session of intracanal Nd:YAG laser irradiation is able to neutralize endotoxin in the dental root tissues.

  6. Effects of dentin surface treatments including Er,Cr:YSGG laser irradiation with different intensities on the push-out bond strength of the glass fiber posts to root dentin.

    PubMed

    Kirmali, Omer; Kustarci, Alper; Kapdan, Alper; Er, Kursat

    2015-07-01

    Intra-canal post systems are commonly used to restore root-filled teeth. Bond strengths of the posts can be affected by various surface treatments of the post or the dentin. The aim of this study was to evaluate the effects of dentin surface treatments including erbium-chromium; yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation with different intensities on the push-out bond strength of the glass fiber posts to root dentin. Forty single-rooted human maxillary incisors were filled and post spaces were prepared. After these procedures, the specimens were divided randomly into four groups according to the dentin surface treatments, as follows: (i) untreated surface (control), (ii) 1W Er,Cr:YSGG laser application, (iii) 2W Er,Cr:YSGG laser application and (iv) 3W Er,Cr:YSGG laser application. Then the posts were cemented into the root canals using dual-cured resin cement. Bonded specimens were cut into 1-mm-thick slices and push-out tests were performed using a universal testing device. All specimens were loaded until fracture and the failure modes were evaluated with a stereomicroscope at 32× magnification. Representative specimens were analyzed by scanning electron microscopy. Data were analyzed using a one-way ANOVA, Tukey and Wilcoxon tests. The bond strength values ranged from 3.22-4.68 MPa. There were no statistically significant differences among the groups, regardless of the different levels. The coronal and middle levels of the post space had significantly higher bond strength values compared with the apical level (p < 0.05). Er,Cr:YSGG laser irradiation with different intensities did not increase the bond strength of the fiber posts to the root canal dentin walls.

  7. How to bond to root canal dentin

    NASA Astrophysics Data System (ADS)

    Nica, Luminita; Todea, Carmen; Furtos, Gabriel; Baldea, Bogdan

    2014-01-01

    Bonding to root canal dentin may be difficult due to various factors: the structural characteristic of the root canal dentin, which is different from that of the coronal dentin; the presence of the organic tissue of the dental pulp inside the root canal, which has to be removed during the cleaning-shaping of the root canal system; the smear-layer resulted after mechanical instrumentation, which may interfere with the adhesion of the filling materials; the type of the irrigants used in the cleaning protocol; the type of the sealer and core material used in the obturation of the endodontic space; the type of the materials used for the restoration of the endodontically treated teeth. The influence of the cleaning protocol, of the root canal filling material, of the type of the adhesive system used in the restoration of the treated teeth and of the region of the root canal, on the adhesion of several filling and restorative materials to root canal dentin was evaluated in the push-out bond strength test on 1-mm thick slices of endodontically treated human teeth. The results showed that all these factors have a statistically significant influence on the push-out bond strength. Formation of resin tags between radicular dentin and the investigated materials was observed in some of the samples at SEM analysis.

  8. Effects of different desensitizing treatments on root dentin permeability.

    PubMed

    Rosa, Raydsa Raíssa Moura; Calazans, Francielle Karoline Santos; Nogueira, Ruchele Dias; Lancellotti, Ailla Carla Rocha Acosta; Gonçalves, Luciano de Sousa; Geraldo-Martins, Vinícius Rangel

    2016-10-10

    The objective of this study was to evaluate the effects of diode laser and a desensitizing dentifrice on dentin permeability. Fifty-two root dentin fragments were obtained (5 × 5mm) and treated with 24% EDTA gel. The samples were divided into 4 groups (n = 13): G1, control (no treatment); G2, diode laser (λ = 908 nm, 1.5 W, continuous mode, 20s); G3, application of abrasive dentifrice for 1 minute (Elmex Sensitive Professional (International Gaba); and G4, application of abrasive dentifrice for 1 minute followed by irradiation with diode laser. Ten samples per group were immersed in 2% methylene blue solution for 4h. The specimens were washed, longitudinally sectioned, observed under optical microscopy, photographed and assessed based on the degree of dye leakage. The remaining samples were observed under scanning electron microscopy (SEM). The leakage data were subjected to ANOVA test, followed by Tukey's t-test (α = 5%). Groups 2, 3 and 4 showed less dye penetration than the control group (p < 0.05), but were similar among each other. SEM images showed that dentinal tubules were open in G1, and fused and occluded in G2. Group 3 showed dentinal tubules that were occluded by the metal ions from the toothpaste. G4 presented similar characteristics to G3, and the presence of fused dentin. The diode laser and the dentifrice were effective in reducing dentinal permeability, and the combination of the two treatments did not show better results than either one used alone.

  9. Effect of dentinal tubules and resin-based endodontic sealers on fracture properties of root dentin.

    PubMed

    Jainaen, Angsana; Palamara, Joseph E A; Messer, Harold H

    2009-10-01

    To investigate the role of dentinal tubules in the fracture properties of human root dentin and whether resin-filled dentinal tubules can enhance fracture resistance. Crack propagation in human root dentin was investigated in 200 microm thick longitudinal samples and examined by light and scanning electron microscopy. 30 maxillary premolar teeth were prepared for work of fracture (Wf) test at different tubule orientations, one perpendicular and two parallel to dentinal tubules. Another 40 single canal premolars were randomly divided into four groups of 10 each: intact dentin, prepared but unobturated canal, canal obturated with epoxy rein (AH Plus/gutta percha), or with UDMA resin sealer (Resilon/RealSeal. The samples were prepared for Wf test parallel to dentinal tubules. Wf was compared under ANOVA with statistical significance set at p<0.05. Dentinal tubules influenced the path of cracks through dentin, with micro-cracks initiated in peritubular dentin of individual tubules ahead of the main crack tip. A significant difference (p<0.001) was found between Wf perpendicular to tubule direction (254.9 J/m(2)) vs. parallel to tubule direction from inner to outer dentin (479.4 J/m(2)). Neither canal preparation nor obturation using epoxy- or UDMA-based resins as sealer cements substantially influenced fracture properties of root dentin, despite extensive infiltration of dentinal tubules by both sealer cements.

  10. Effect of periodontal root planing on dentin permeability.

    PubMed

    Fogel, H M; Pashley, D H

    1993-10-01

    The purpose of this study was to quantitate the effects of root planing on the permeability of human root dentin in vitro. Unerupted 3rd molars were used. The crowns were removed and longitudinal slices made of the root. The hydraulic conductance of the root dentin was measured before and after root planing, acid etching and potassium oxalate application using a fluid filtration method. The results showed that root planing creates a smear layer that reduces the permeability of the underlying dentin. However, this smear layer is acid labile. Thus, root planing may ultimately cause increased dentin permeability and the associated sequelae of sensitive dentin, bacterial invasion of tubules, reduced periodontal reattachment and pulpal irritation.

  11. Evaluation of the Morphological Characteristics of Laser-Irradiated Dentin

    PubMed Central

    Lilaj, Bledar; Franz, Alexander; Degendorfer, Daniela; Moritz, Andreas

    2015-01-01

    Abstract Objective: The aim of this study was to investigate the effect of different energy settings of Er:YAG laser irradiation on dentin surface morphology with respect to the number of opened dentinal tubules. Background data: An ideally prepared dentin surface with opened dentinal tubules is a prerequisite for adhesive fixation. No study, however, has yet compared the numbers of opened dentinal tubules with regard to statistical differences. Methods: Conventional preparations using a bur with or without additional acid etching acted as control groups. Dentin specimens were prepared from human third molars and randomly divided into eight groups according to the energy settings of the laser (1, 1.5, 4, 6, 7.5, and 8 W) and two controls (bur and bur plus acid etching). After surface preparation, dentin surfaces were analyzed with a scanning electron microscope, and the number of opened dentinal tubules in a defined area was counted. Results: The control groups showed smooth surfaces with (bur plus acid etching) and without opened dentinal tubules (bur), whereas all laser-irradiated surfaces showed rough surfaces. Using the energy setting of 4 W resulted in significantly more opened dentinal tubules than the conventional preparation technique using the bur with additional acid etching. In contrast, the energy setting of 8 W showed significantly fewer opened dentinal tubules, and also exhibited signs of thermal damage. Conclusions: The Er:YAG laser with an energy setting of 4 W generates a dentin surface with opened dentinal tubules, a prerequisite for adhesive fixation. PMID:26389986

  12. Dentin permeability: effects of endodontic procedures on root slabs.

    PubMed

    Fogel, H M; Pashley, D H

    1990-09-01

    The permeability of human radicular dentin was measured as a hydraulic conductance before and after treatment with K files and before and after subsequent treatment of the endodontic smear layer with NaOCl, 50% citric acid, or 3% monopotassium-monohydrogen oxalate. Filing reduced dentin permeability 25 to 49%, respectively, depending upon whether outer or inner root dentin was filed. The permeability of these smear layers was unaffected by 5% NaOCl but increased many times after treatment with 50% citric acid for 2 min. Oxalate treatment lowered root dentin permeability to levels below that produced by creation of smear layers due to the production of a crystalline precipitate.

  13. Effect of endodontic procedures on root dentin permeability.

    PubMed

    Tao, L; Anderson, R W; Pashley, D H

    1991-12-01

    The purpose of this study was to quantitate the sequential effects of endodontic procedures on the permeability of human root dentin in vitro. Forty single-rooted teeth were used. Both the crown and the apical 2 mm of the root were removed. The hydraulic conductance of the root before and after various endodontic procedures was measured using a fluid filtration method. Measurements were also made of dentin thickness, intracanal diameter changes, and changes in intracanal surface area. The results showed that instrumentation by K files alone or in combination with Gates Glidden drills did not alter radicular dentin permeability when the cementum remained intact. After removing the cementum, the creation of a smear layer and smear plugs on the canal surface tended to offset the expected increase in dentin permeability created by increasing the intracanal surface area and decreasing root dentin thickness. EDTA treatment inside the instrumented canal to remove the smear layer did not increase permeability significantly. The use of K files followed by Gates Glidden drills tended to remove more cervical dentin, increased the intracanal surface area, and increased the hydraulic conductance of root dentin more than the use of K files alone.

  14. Effect of solvents on bonding to root canal dentin.

    PubMed

    Erdemir, Ali; Eldeniz, Ayce Unverdi; Belli, Sema; Pashley, David H

    2004-08-01

    The long-term success of resin cementation of post/cores is likely increased with improvement in resin-root canal dentin bonding. The adverse effect of some irrigation constituents (NaOCl, H2O2) or medications (eugenol) on the bond strengths of resins to dentin have been reported. The purpose of this in vitro study was to evaluate the effect of two gutta-percha solvents (chloroform versus halothane) on microtensile bond strength to root canal dentin. Thirty, extracted, human, single-rooted teeth were instrumented to a #70 file and randomly divided into 3 groups of 10 each. The root canals were treated with water, chloroform, or halothane for 60 s. All root canals were obturated using C&B Metabond. After 24 h of storage in distilled water, serial 1-mm-thick cross-sections were cut and trimmed. Microtensile bond strength to apical, middle, and coronal root canal dentin were measured using an Instron machine. Using pooled data, the results indicated that water-treated roots had significantly higher resin-dentin bond strengths compared with chloroform or halothane treatment groups (control: 23.9 MPa; chloroform: 18.3 MPa; halothane: 17 MPa; p < 0.05). Gutta-percha solvents have an adverse effect on bond strengths of adhesive cements to root canal dentin.

  15. Ultrastructural evaluation of radicular dentin after Nd:YAG laser irradiation combined with different chemical substances.

    PubMed

    Faria, Maria Isabel Anastacio; Souza-Gabriel, Aline Evangelista; Marchesan, Melissa Andreia; Sousa-Neto, Manoel Damiao; Silva-Sousa, Yara Teresinha Correa

    2008-01-01

    This aticle sought to evaluate the dentin morphology after irradiation by a Neodymium:Yttrium-Aluminum-Garnet (Nd:YAG) laser, using different chemical substances to irrigate radicular canals: distilled water, 17% ethylenediaminetetraacetic acid plus Cetavlon (EDTAC), 1% sodium hypochlorite, and 2% chlorhexidine. Groups were subdivided according to the protocol of laser application (n=9). The specimens were analyzed by scanning electron microscopy (SEM). No differences were found in dentin morphology when different root thirds were examined. Regardless of the chemical substance used, alterations were more evident in groups in which the surfaces were dried before laser irradiation. Fusion areas, craters, carbonization, and partially exposed tubules were verified. When the irradiation was performed in water, the smear layer was incorporated into the laser-modified surface. Among the specimens irrigated with EDTAC and laser-treated, partial obliteration of dentin tubules due to the laser action was verified; in addition, there was no remaining smear layer on the surfaces. Samples irrigated with sodium hypochlorite followed by laser irradiation demonstrated similar morphology to the samples in the chlorhexidine group, with some fusion areas present and no exposed dentin tubules or fissures. The irradiation from an Nd:YAG laser in the presence of EDTAC solution provided a more favorable surface pattern compared to the other experimental conditions, due to the removal of the contaminated layer and the posterior sealing of dentin tubules.

  16. Abrasion of eroded root dentine brushed with different toothpastes.

    PubMed

    De Menezes, Márcio; Turssi, Cecilia Pedroso; Hara, Anderson Takeo; Messias, Danielle Cristine Furtado; Serra, Mônica Campos

    2004-09-01

    This study evaluated the surface roughness change and wear provided by different dentifrices on root dentine previously exposed to erosive challenges. According to a randomized complete block design, 150 slabs of bovine root dentine (6 x 3 x 2 mm) were ground flat and polished. In an area of 4 x 3 mm on the dentine surface, specimens were submitted to five erosive/abrasive events, each one composed by: exposure to Sprite Diet or distilled water for 5 min, then to a remineralizing solution for 1 min, and simulation of 5,000 brushing strokes. Four dentifrices--regular (RE), baking soda (BS), whitening (WT) and tartar control (TC)--and distilled water (CO), used as control, were compared. Final texture and the wear depth were evaluated using a profilometer. ANOVA did not show significant interaction, indicating that the effect of dentifrices on both surface roughness change and wear did not depend on whether or not the dentine was eroded ( p>0.05). There was no difference between abrasion of eroded and sound dentine. The Tukey's test revealed that WT, BS and TC provided the highest increase in surface roughness differing from RE and CO. TC yielded the deepest wear of root dentine, whereas RE and CO, the shallowest. No significant difference in wear among BS, TC and WT were observed. Within the limitations of this study, the data showed that abrasion of both eroded and sound root dentine was dependent on the dentifrice used.

  17. Lack of dentin acid resistance following 9.3 um CO2 laser irradiation

    NASA Astrophysics Data System (ADS)

    Le, Charles Q.; Fried, Daniel; Featherstone, John D. B.

    2008-02-01

    Previous studies have shown that laser irradiation of dental enamel by specific carbon dioxide laser conditions can inhibit subsequent acid dissolution of the dental enamel surface. The purpose of this study was to determine whether similar carbon dioxide laser conditions would have a protective effect on dentin. Blocks of human dentin roots (3x3 mm2) were irradiated at 9.3 µm wavelength with a 15-18 µs pulse duration laser and fluences of 0.50-1.50 J/cm2. A motion controller system was used to ensure uniform irradiation of the entire dentin surface. Surface acid dissolution profiles following irradiation were acquired for the five study groups, control group (Non-irradiated) and four laser-treated groups. Dissolution profiles of low fluence groups (0.50 and 0.75 J/cm2) exhibited similar profiles to the control group. Dissolution profiles of higher fluence groups (1.0 and 1.5 J/cm2) showed an increased dissolution rate over the control group, but these differences were not statistically significant (p>0.05). This study demonstrated that the application of carbon dioxide laser irradiation significantly alters the surface of dentin but did not decrease the acid dissolution rate.

  18. Effect of two restorative materials on root dentine erosion.

    PubMed

    Domiciano, Silvia Jorge; Colucci, Vivian; Serra, Mônica Campos

    2010-05-01

    This study sought to evaluate the microhardness of root dentine adjacent to glass-ionomer and composite resin restorations after erosive challenge. A crossover study was performed in two phases of 4 consecutive days each. One hundred twelve bovine root dentine slabs were obtained, and standardized box-shaped cavities were prepared at center of each specimen. The prepared cavities were randomly restored with glass-ionomer cement or composite resin. The slabs were randomly assigned among 14 volunteers, which wore intraoral palatal device containing four restored root dentin slabs. Starting on the second day, half of the palatal acrylic devices were immersed extraorally in a lemonade-like carbonated soft drink for 90 s, four times daily for 3 days. After 3-day wash-out, dentine slabs restored with the alternative material were placed into palatal appliance and the volunteers started the second phase of this study. After erosive challenges, microhardness measurements were performed. Regardless of the restorative material employed, eroded specimens demonstrated lower microhardness value (p < 0.0001). At eroded condition examined in this study, dentine restored with glass-ionomer cement showed higher microhardness values (p < 0.0001). It may be concluded that the glass-ionomer cement decreases the progression of root dentine erosion at restoration margin. (c) 2010 Wiley Periodicals, Inc.

  19. Changes in acid resistance of dentin irradiated by a CW 10.6 μm CO2 laser

    NASA Astrophysics Data System (ADS)

    Featherstone, John D. B.; Le, Charles Q.; Hsu, Dennis; Manesh, Saman; Fried, Daniel

    2008-02-01

    The overall objective of our studies is to establish laser conditions that can be used clinically for the prevention or treatment of early carious lesions in dental enamel and dentin. Previous studies have shown that laser irradiation of dental enamel by specific carbon dioxide laser conditions can inhibit subsequent acid dissolution of the dental enamel surface. The purpose of this study was to determine whether irradiation of dentin by a continuous wave 10.6 µm carbon dioxide laser would inhibit acid dissolution. Blocks of human dentin roots (3x3 mm2) were irradiated at 10.6 µm wavelength with power settings of 0.5, 0.75, 1.0, 1.5 and 2.0 watts. A motion controller system was used to ensure uniform irradiation of the entire dentin surface. Surface acid dissolution profiles following irradiation were acquired for the irradiated groups and a non-irradiated control group. Dissolution rates for 0.5 and 0.75 watts were not statistically significant (p>0.05) from the control group, whereas irradiation at 1.0 watts and higher significantly (p<0.05) increased the acid dissolution rate. Considerable surface damage occurred at these higher powers. This study demonstrated that irradiation of dentin by a continuous wave 10.6 µm carbon dioxide but did not decrease the acid dissolution rate, and was detrimental at powers of 1.0 watts and above.

  20. Penetration of varnishes into demineralized root dentine in vitro.

    PubMed

    Arends, J; Duschner, H; Ruben, J L

    1997-01-01

    In this paper the penetration of three different varnishes employed in caries prevention (Duraphat, Fluor Protector and Cervitec) into demineralized dentine is quantified using confocal laser scanning microscopy. The results show that the varnish penetration into lesions about 85 microns in depth if for Cervitec about 35 microns and considerably less for Duraphat and Fluor Protector. The penetration is into the dentinal tubules and is influenced by dentinal tubule direction. The drying procedure--pretreatment of the dentine--influences the penetration, though sizeably only for Cervitec applications. This paper shows that varnish penetration into the tissue and presumably 'sealing' tubules completely or partly is valuable with respect to root caries prevention and hypersensitivity.

  1. An In Vitro Comparison of the Bond Strength of Composite to Superficial and Deep Dentin, Treated With Er:YAG Laser Irradiation or Acid-Etching

    PubMed Central

    Alaghehmand, Homayoon; Nezhad Nasrollah, Fatemeh; Nokhbatolfoghahaei, Hanieh; Fekrazad, Reza

    2016-01-01

    Introduction: The aim of this study was to compare the micro-shear bond strength of composite resin on superficial and deep dentin after conditioning with phosphoric acid and Erbium-Doped Yttrium Aluminum Garnet (Er:YAG) laser. Methods: Thirty human molars were selected, roots were removed and crowns were bisected to provide a total of 60 half-crowns. Specimens were ground to expose superficial and deep dentin. Samples were assigned to six groups: (1) AS (acid etching of superficial dentin); (2) AD (acid etching of deep dentin); (3) LS (Er:YAG laser irradiation on superficial dentin); (4) LD (Er:YAG laser irradiation on deep dentin); (5) LAS (Er:YAG laser irradiation on superficial dentin followed by acid etching); (6) LAD (Er:YAG laser irradiation on deep dentin followed by acid etching) The adhesive protocol was performed. Samples were thermocycled and micro-shear bond strength was tested to failure. The data were submitted to statistical analysis with one-way analysis of variance (ANOVA) and Tukey post hoc test. Results: The AS group, demonstrated the greatest amount of micro-shear bond strength. Statistical analysis showed a decrease in bond strength in laser-treated groups which was more significant for deep dentin. Conclusion: Preparation of dentin with laser did not improve bonding to superficial and deep dentin. PMID:28144437

  2. An In Vitro Comparison of the Bond Strength of Composite to Superficial and Deep Dentin, Treated With Er:YAG Laser Irradiation or Acid-Etching.

    PubMed

    Alaghehmand, Homayoon; Nezhad Nasrollah, Fatemeh; Nokhbatolfoghahaei, Hanieh; Fekrazad, Reza

    2016-01-01

    Introduction: The aim of this study was to compare the micro-shear bond strength of composite resin on superficial and deep dentin after conditioning with phosphoric acid and Erbium-Doped Yttrium Aluminum Garnet (Er:YAG) laser. Methods: Thirty human molars were selected, roots were removed and crowns were bisected to provide a total of 60 half-crowns. Specimens were ground to expose superficial and deep dentin. Samples were assigned to six groups: (1) AS (acid etching of superficial dentin); (2) AD (acid etching of deep dentin); (3) LS (Er:YAG laser irradiation on superficial dentin); (4) LD (Er:YAG laser irradiation on deep dentin); (5) LAS (Er:YAG laser irradiation on superficial dentin followed by acid etching); (6) LAD (Er:YAG laser irradiation on deep dentin followed by acid etching) The adhesive protocol was performed. Samples were thermocycled and micro-shear bond strength was tested to failure. The data were submitted to statistical analysis with one-way analysis of variance (ANOVA) and Tukey post hoc test. Results: The AS group, demonstrated the greatest amount of micro-shear bond strength. Statistical analysis showed a decrease in bond strength in laser-treated groups which was more significant for deep dentin. Conclusion: Preparation of dentin with laser did not improve bonding to superficial and deep dentin.

  3. Elemental analysis of caries-affected root dentin and artificially demineralized dentin

    PubMed Central

    Sung, Young-Hye; Son, Ho-Hyun; Yi, Keewook

    2016-01-01

    Objectives This study aimed to analyze the mineral composition of naturally- and artificially-produced caries-affected root dentin and to determine the elemental incorporation of resin-modified glass ionomer (RMGI) into the demineralized dentin. Materials and Methods Box-formed cavities were prepared on buccal and lingual root surfaces of sound human premolars (n = 15). One cavity was exposed to a microbial caries model using a strain of Streptococcus mutans. The other cavity was subjected to a chemical model under pH cycling. Premolars and molars with root surface caries were used as a natural caries model (n = 15). Outer caries lesion was removed using a carbide bur and a hand excavator under a dyeing technique and restored with RMGI (FujiII LC, GC Corp.). The weight percentages of calcium (Ca), phosphate (P), and strontium (Sr) and the widths of demineralized dentin were determined by electron probe microanalysis and compared among the groups using ANOVA and Tukey test (p < 0.05). Results There was a pattern of demineralization in all models, as visualized with scanning electron microscopy. Artificial models induced greater losses of Ca and P and larger widths of demineralized dentin than did a natural caries model (p < 0.05). Sr was diffused into the demineralized dentin layer from RMGI. Conclusions Both microbial and chemical caries models produced similar patterns of mineral composition on the caries-affected dentin. However, the artificial lesions had a relatively larger extent of demineralization than did the natural lesions. RMGI was incorporated into the superficial layer of the caries-affected dentin. PMID:27847746

  4. Apical microleakage and SEM analysis of dentin surface after 980 nm diode laser irradiation.

    PubMed

    Faria, Maria Isabel Anastácio; Souza-Gabriel, Aline Evangelista; Alfredo, Edson; Messias, Danielle Cristine Furtado; Silva-Sousa, Yara Teresinha Correa

    2011-01-01

    This study evaluated the effect of 980-nm diode laser on apical microleakage and intraradicular dentin morphology. Roots of 110 mandibular incisors were used in the study: 92 for microleakage test and 18 for scanning electron microscopy (SEM). Roots were randomly assigned to 3 groups according to the irrigating solution (water, NaOCl and NaOCl/EDTA) and were divided into 3 subgroups according to the laser irradiation protocol (without irradiation, irradiated at 1.5 W and irradiated at 3.0 W). Two specimens of each subgroup were prepared for SEM. The remaining roots were filled with AH Plus and gutta-percha. Apical leakage was assessed by ink penetration and data were analyzed statistically by ANOVA and Tukey-Krammer test (α=0.05). SEM analysis showed intensification of changes with increase of laser power as well as variations according to the irrigating solution. Modified smear layer was observed in specimens treated with water and irradiated with laser. Roots irrigated with NaOCl/EDTA had lower levels of infiltration (0.17 ± 0.18 mm) differing significantly (p<0.05) from those of roots irrigated with water (0.34 ± 0.30 mm), but similar (p>0.05) to those irrigated with NaOCl (0.28 ± 0.29 mm). Non-irradiated roots had lower levels of infiltration (0.10 ± 0.14 mm), differing (p<0.05) from those irradiated at 1.5 W (0.32 ± 0.22 mm) and 3.0 W (0.37 ± 0.32 mm). The 980 nm diode laser modified dentin morphology and increased apical microleakage.

  5. The combined use of Er,Cr:YSGG laser and fluoride to prevent root dentin demineralization

    PubMed Central

    GERALDO-MARTINS, Vinícius Rangel; LEPRI, Cesar Penazzo; FARAONI-ROMANO, Juliana Jendiroba; PALMA-DIBB, Regina Guenka

    2014-01-01

    The use of erbium lasers to prevent caries in enamel has shown positive results. However, it is not known if Er,Cr:YSGG laser can also be used to increase acid resistance of root dentine, which is another dental tissue susceptible to the action of cariogenic bacteria. Objective To analyze the effects of the Er,Cr:YSGG laser (λ=2.78 μm, 20 Hz) irradiation associated with 2% neutral sodium fluoride (NaF) to prevent root dentin demineralization. Material and Methods One hundred human root dentin samples were divided into 10 groups (G) and treated as follows: G1: no treatment; G2: NaF; G3: laser (4.64 J/cm2) with water cooling (WC=5.4 mL/min); G4: laser (4.64 J/cm2) without WC; G5: laser (8.92 J/cm2) with WC; G6: laser (8.92 J/cm2) without WC; G7: laser (4.64 J/cm2) with WC and NaF; G8: laser (4.64 J/cm2) without WC and NaF; G9: laser (8.92 J/cm2) with WC and NaF; G10: laser (8.92 J/cm2) without WC and NaF. The NaF gel was applied alone or after 4 min of irradiation. After 14 days of acid challenge, the samples were sectioned and the Knoop microhardness (KHN) test was done at different depths (30, 60, 90 and 120 μm) from the outer dentin surface. Data were analyzed by one-way ANOVA and Fisher's test (α=5%). Results The results showed that G8 and G10 presented higher KHN than the G1 for the depths of 30 and 60 μm, indicating an increase of the acid resistance of the dentin in up to 35% (p<0.05). Conclusions The use of Er,Cr:YSGG laser irradiation at 4.64 J/ cm2 and 8.92 J/cm2 without water cooling and associated with 2% NaF can increase the acid resistance of human root dentin. PMID:25466479

  6. Flexural properties of endodontic posts and human root dentin.

    PubMed

    Plotino, Gianluca; Grande, Nicola M; Bedini, Rossella; Pameijer, Cornelis H; Somma, Francesco

    2007-09-01

    To evaluate the flexural modulus and flexural strength of different types of endodontic post in comparison with human root dentin. Three different types of fiber-reinforced composite (FRC) posts and three metal posts each comprising 10 specimens (n=10) and 20 dentin bars were loaded to failure in a three-point bending test to determine the flexural modulus (GPa) and the flexural strength (MPa). Three randomly selected fiber posts of each group were evaluated using a scanning electron microscope (SEM) to illustrate the differences in mode of fracture. Data were subjected to a one-way ANOVA to determine significant differences between groups and the Bonferroni t-test multiple comparison was applied to investigate which mean values differed from one another with significance levels of P<0.05. The flexural modulus recorded for the dentin bars was 17.5+/-3.8 GPa. The values for posts ranged from 24.4+/-3.8 GPa for silica fiber posts to 108.6+/-10.7 GPa for stainless steel posts. The flexural strength for dentin was 212.9+/-41.9 MPa, while the posts ranged from 879.1+/-66.2 MPa for silica fiber posts to 1545.3+/-135.9 MPa for cast gold posts. The ANOVA test analysis revealed significant differences between groups (P<0.05) for flexural modulus and flexural strength mean values. FRC posts have an elastic modulus that more closely approaches that of dentin while that for metal posts was much higher. The flexural strength of fiber and metal posts was respectively four and seven times higher than root dentin.

  7. Effect of two contemporary root canal sealers on root canal dentin microhardness

    PubMed Central

    2017-01-01

    Background Successful root canal treatment depends on proper cleaning, disinfecting and shaping of the root canal space. Pulpless teeth have lower dentin microhardness value compared to that of vital teeth. A material which can cause change in dentin composition may affect the microhardness. Thus the aim of this study was to evaluate and compare the effect of two root canal sealers on dentin microhardness. Material and Methods Forty two single rooted teeth were selected and divided into 3 equal groups; Apexit, iRootSP and control groups (n=14) Each group was then divided into 2 subgroups according to the post evaluation period; 1 week and 2 months (n=7). Root canal procedure was done in the experimental groups and obturation was made using either; Apexit, iRootSP or left unprepared and unobturated in the control group. Roots were sectioned transversely into cervical, middle and apical segments. The three sections of each root were mounted in a plastic chuck with acrylic resin. The coronal dentin surfaces of the root segments werepolished. Microhardness of each section was measured at 500 µm and 1000 µm from the canal lumen. Results Four way-ANOVA revealed that different tested sealer materials, canal third, measuring distance from the pulp and time as independent variables had statistically non significant effect on mean microhardness values (VHN) at p≤0.001. Among iRootSP groups there was a statistically significant difference between iRoot SP at coronal root portion (87.79±17.83) and iRoot SP at apical root portion (76.26±9.33) groups where (p=0.01). IRoot SP at coronal canal third had higher statistically significant mean microhardness value (87.79±17.83) compared to Apexit at coronal third (73.61±13.47) where (p=0.01). Conclusions Root canal sealers do not affect dentin microhardness. Key words:Root canal, dentin, sealers, microhardness, bioceramic. PMID:28149466

  8. Shear bond strength of two resin cements to human root dentin using three dentin bonding agents.

    PubMed

    Gogos, C; Stavrianos, C; Kolokouris, I; Economides, N; Papadoyannis, I

    2007-01-01

    This study compared the bond strength of two resin cements to human root dentin when used with three bonding agents. The materials used were Rely X ARC and Perma Cem, two one-bottle bonding agents (Single Bond, Bond-1) and one self-etching bonding agent (Clearfil SE Bond). The dentin was obtained from single rooted human teeth, and the specimens were treated with either 15% EDTA or 37% phosphoric acid to remove the smear layer, except in groups where the self-etching bonding agent was used. The resin cements were placed on dentin surfaces with the use of bonding agents. Shear bond strength (SBS) was tested using a single plane shear test assembly. The dentin specimens were divided into 10 groups. Eight groups were pre-treated with EDTA or phosphoric acid to remove the smear layer, followed by a bonding agent (Bond-1 or Single Bond) and resin cement (Rely X or Perma Cem). In the two remaining groups, the smear layer was left intact, and the two resins cements were used in combination with the self-etching bonding agent (Clearfil SE Bond). No statistically significant differences were observed among the eight groups treated with one-bottle bonding agents. The mean bond strengths of the two groups treated with the self-etching bonding agent did not differ significantly from each other but were both significantly greater than the bond strengths of all the other groups. The results of this study also showed that EDTA can be used as an alternative to phosphoric acid in bonding procedures for resin cements. However, the bond strengths of resin cements, in combination with a self-etching bonding agent, were significantly greater than those of the same cements when used with one-bottle bonding agents.

  9. In vivo model for microbial invasion of tooth root dentinal tubules

    PubMed Central

    BRITTAN, Jane L; SPRAGUE, Susan V; MACDONALD, Emma L; LOVE, Robert M; JENKINSON, Howard F; WEST, Nicola X

    2016-01-01

    ABSTRACT Objective Bacterial penetration of dentinal tubules via exposed dentine can lead to root caries and promote infections of the pulp and root canal system. The aim of this work was to develop a new experimental model for studying bacterial invasion of dentinal tubules within the human oral cavity. Material and Methods Sections of human root dentine were mounted into lower oral appliances that were worn by four human subjects for 15 d. Roots were then fixed, sectioned, stained and examined microscopically for evidence of bacterial invasion. Levels of invasion were expressed as Tubule Invasion Factor (TIF). DNA was extracted from root samples, subjected to polymerase chain reaction amplification of 16S rRNA genes, and invading bacteria were identified by comparison of sequences with GenBank database. Results All root dentine samples with patent tubules showed evidence of bacterial cell invasion (TIF value range from 5.7 to 9.0) to depths of 200 mm or more. A spectrum of Gram-positive and Gram-negative cell morphotypes were visualized, and molecular typing identified species of Granulicatella, Streptococcus, Klebsiella, Enterobacter, Acinetobacter, and Pseudomonas as dentinal tubule residents. Conclusion A novel in vivo model is described, which provides for human root dentine to be efficiently infected by oral microorganisms. A range of bacteria were able to initially invade dentinal tubules within exposed dentine. The model will be useful for testing the effectiveness of antiseptics, irrigants, and potential tubule occluding agents in preventing bacterial invasion of dentine. PMID:27119760

  10. Diode laser irradiation effects on the sealing ability of root canal sealers

    NASA Astrophysics Data System (ADS)

    Ribeiro, A. C.; Nogueira, G. E. C.; Mayer, M. P. A.; Antoniazzi, J. H.; Zezell, D. M.

    2010-06-01

    This study aimed to test the hypothesis that dentine alterations induced by 810 nm-diode laser may affect the interaction between root canal sealers and the dentin wall. Seventy-two single root human teeth were selected and root canals were enlarged with K-files. Dentine was treated with 0.5% NaOCl and 17% EDTA-T and irradiated (laser group) by diode laser (810 nm/ P = 2.5W/ I = 1989 W/cm2) or remained non-irradiated (control group). Six samples per group were analyzed by scanning electron microscopy (SEM). The remaining samples of each group were divided into three subgroups ( n = 10) and sealed with one of the tested sealers (N-Rickert/AHPlus™/Apexit®). Apical leakage was estimated by evaluating penetration of 0.5% methylene-blue dye. SEM analysis revealed that dentine at the apical third in irradiated samples was melted and fusioned whereas non-irradiated samples exhibited opened dentinal tubules. Despite the morphological changes induced by irradiation, laser did not affect the sealing ability of N-Rickert and AHPlusTM sealers. However, the length of apical leakage in roots filled with Apexit® was lower in irradiated root canals than in non-irradiated samples ( p < 0.05). Morphological changes of root canal walls promoted by diode laser irradiation may improve de sealing ability of Apexit®, a calcium hydroxide-based sealer, suggesting that improved sealing promoted by irradiation may represent an additional factor contributing to the endodontic clinical outcome.

  11. A rapid non-destructive method for root dentin moisture measurements

    PubMed Central

    Komabayashi, Takashi; Zhu, Qiang; Jiang, Jin; Safavi, Kamran E.; Spångberg, Larz S.W.

    2009-01-01

    Dentin moisture content is important in adhesive bonding and structural strength research. However, there is no rapid method available to assess dentin moisture without sample destruction. This study examined the use of a digital grain moisture meter to measure root dentin moisture in vitro. Extracted mandibular single rooted teeth were sectioned at the CEJ. The moisture of the root dentin was measured at six measuring modes for different grains and repeated five times. Dentin weight changes before and after drying were measured to obtain control values. The control values were compared with machine readings. In conclusion, (1) Each non-destructive measurement took less than 30 seconds. (2) 24 hours storage at 37°C and 100 % humidity did not restore dentin moisture. (3) Five grain modes had a high validity, and could be used for dentin moisture measurements. PMID:19157921

  12. Dentine hypersensitivity. The effects in vitro of acids and dietary substances on root-planed and burred dentine.

    PubMed

    Addy, M; Absi, E G; Adams, D

    1987-05-01

    Evidence indicates that teeth exhibiting cervical dentine hypersensitivity have open dentinal tubules at the dentine surface. The identification of factors which render dentine exposed and tubules open is important both to the prevention and management of dentine hypersensitivity. In this study, recently extracted teeth were root planed or burred to expose the root dentine. Specimens were horizontally sectioned and then using the apical portion as control, the coronal portions placed in a variety of strong and weak acids and dietary fluids. Examination under the scanning electron microscope revealed a smear layer covering completely underlying tubules on the control root planed or burred portions. Test portions exposed to strong and weak acids showed loss of the smear layer and exposure of large numbers of tubules. Formic and tannic acids produced no changes. Some dietary fluids, in particular red and white wine, citrus fruit juices, apple juice and yogurt produced similar etching effects to the acids. The low pH carbonated drink, coca-cola, and a blackcurrent cordial produced no effects. The results of this study in vitro cannot necessarily be extrapolated to the clinical situation, but suggest that certain dietary factors could play a rôle in the aetiology of dentine hypersensitivity. Dietary advice to patients may prove important in the management of this often recurrent condition.

  13. Periapical Microsurgery: Can Ultrasonic Root-end Preparations Clinically Create or Propagate Dentinal Defects?

    PubMed

    Tawil, Peter Z

    2016-10-01

    This clinical study evaluates the effect of ultrasonic root-end preparations on dentinal defect creation and propagation. Eighty-four teeth were treated with periapical microsurgery using a modern microsurgical protocol in a private practice setting. The root apices were resected and inspected for dentinal defects with a surgical operating microscope and a 0.8-mm diameter light-emitting diode microscope diagnostic probe light, both before and after ultrasonic root-end preparations. A 3-grade scale (none, partial, and full dentinal defect) was used to assess the status of the roots before and after ultrasonic root-end preparation. Of the 84 treated teeth, 3 had a vertical root fracture, leaving a total of 81 teeth for assessment. Fifty-one teeth were intact upon resection and remained intact after root-end preparation. Twenty-six teeth had partial dentinal defects, and 14 (54%) of these propagated into full dentinal defects after root-end preparation. This periapical microsurgery study showed that ultrasonic root-end preparations are safe to use on intact roots. Preexisting dentinal defects can be propagated by ultrasonic root-end preparations. Through the use of light-emitting diodes, dentinal defects can be detected, special root-end management can be implemented, and more predictable outcomes may be achieved. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  14. Root dentine and endodontic instrumentation: cutting edge microscopic imaging

    PubMed Central

    2016-01-01

    Cutting of the dental hard tissues is an integral part of restorative dentistry. Cutting of the root dentine is also needed in preparation prior to endodontic treatment, with significant commercial investment for the development of flexible cutting instruments based around nickel titanium (NiTi) alloys. This paper describes the evolution of endodontic cutting instruments, both in materials used, e.g. the transition from stainless steel to NiTi, and the design of the actual instruments themselves and their method of activation—by hand or motor driven. We have been examining tooth-cutting interactions microscopically for over 25 years using a variety of microscopic techniques; in particular, video-rate confocal microscopy. This has given a unique insight into how many of the procedures that we take for granted are achieved in clinical practice, by showing microscopic video images of the cutting as it occurs within the tooth. This technology has now been extended to allow imaging of the endodontic instrument and the root canal wall for the first time. We are able to image dentine distortion and crack propagation during endodontic filing of the root canal space. We are also able to visualize the often claimed, but seldom seen action of contemporary endodontic instruments. PMID:27274802

  15. Root dentine and endodontic instrumentation: cutting edge microscopic imaging.

    PubMed

    Atmeh, Amre R; Watson, Timothy F

    2016-06-06

    Cutting of the dental hard tissues is an integral part of restorative dentistry. Cutting of the root dentine is also needed in preparation prior to endodontic treatment, with significant commercial investment for the development of flexible cutting instruments based around nickel titanium (NiTi) alloys. This paper describes the evolution of endodontic cutting instruments, both in materials used, e.g. the transition from stainless steel to NiTi, and the design of the actual instruments themselves and their method of activation-by hand or motor driven. We have been examining tooth-cutting interactions microscopically for over 25 years using a variety of microscopic techniques; in particular, video-rate confocal microscopy. This has given a unique insight into how many of the procedures that we take for granted are achieved in clinical practice, by showing microscopic video images of the cutting as it occurs within the tooth. This technology has now been extended to allow imaging of the endodontic instrument and the root canal wall for the first time. We are able to image dentine distortion and crack propagation during endodontic filing of the root canal space. We are also able to visualize the often claimed, but seldom seen action of contemporary endodontic instruments.

  16. Octenidine in root canal and dentine disinfection ex vivo.

    PubMed

    Tandjung, L; Waltimo, T; Hauser, I; Heide, P; Decker, E-M; Weiger, R

    2007-11-01

    The aim of the present study was to investigate the antimicrobial activity of octenidine on Enterococcus faecalis ATCC 29212 in a dentine block model. Fifty-six root segments of extracted human teeth were infected with E. faecalis for 4 weeks. Octenidine-phenoxyethanol gel (1 : 1) was applied for different timing: 1 min, 10 min, 7 days and in a different formula (1 : 3) for 10 min. Three samples were chosen for the group with placebo gel and for the group without infection (negative control). Dentine samples were collected, and the total count of bacteria and colony-forming units were determined. In addition, for controls and the 10 min group with 1 : 1 gel, the proportion of viable bacteria (PVB) was assessed. Octenidine was particularly effective after incubation periods of 10 min and 7 days. The mean PVB decreased significantly from 57.2% to 5.7% after 10 min application. After 7 days, only one of 10 samples showed positive culture. The present study showed the effectiveness of octenidine against E. faecalis in dentine disinfection. Further laboratory and clinical studies are required.

  17. Effect of root canal filling materials containing calcium hydroxide on the alkalinity of root dentin.

    PubMed

    Staehle, H J; Spiess, V; Heinecke, A; Müller, H P

    1995-08-01

    The effect of root canal filling pastes containing calcium oxide resp. calcium hydroxide on the alkalinity of extracted human teeth was investigated using a colour indicator (cresol red). An aqueous suspension of calcium hydroxide (Pulpdent), which is normally used for temporary root canal filling, most consistently produced alkalinity. Removal of the smear layer following instrumentation of the root canal led to increased proportion of alkaline-positive spots in dentinal locations distant from the canal. A clearly smaller effect was found with a calcium salicylate cement (Sealapex) and an oil-paste (Gangraena Merz), both of which are available for definite root canal fillings. Following removal of the smear layer, these hard-setting preparations caused moderate alkalinity in dentin adjacent to the canal but no effect was observed in locations more distant from the canal. Neither at locations adjacent to nor distant from the root canal was alkalinity found when another calcium salicylate cement (Apexit) was used. Apparently the release of hydroxyl ions into root dentin from calcium hydroxide containing root canal filling materials is not solely influenced by the absolute amount of calcium hydroxide, but also depends on other ingredients which variably inhibit the release of these ions.

  18. Essential role of Osterix for tooth root but not crown dentin formation

    PubMed Central

    Zhang, Hua; Jiang, Yong; Qin, Chunlin; Liu, Ying; Ho, Sunita P.; Feng, Jian Q.

    2015-01-01

    Tooth is made of crown and root. It is widely believed that dentin formation in crown and root uses the same regulatory mechanism. However, identification of NFIC’s unique function in determining root but not crown dentin formation challenges the old thought. In searching for the target molecules downstream of NFIC, we unexpectedly found a sharp reduction of OSX (osterix), the key transcription factor in skeleton formation, in the Nfic knockout (KO) tooth root. We then demonstrated a dose-dependent increase of Osx in the odontoblast cell line due to a transient transfection of Nfic expression plasmid. Studies of global and conditional Osx KO mice revealed no apparent changes in the crown dentin tubules and dentin matrix. However, the OSX conditional KO mice (crossed to the 2.3 kb Col 1-Cre) displayed an increase in cell proliferation but great decreases in expressions of root dentin matrix proteins (DMP1 and DSPP), leading to an inhibition in odontoblast differentiation, and short thin root dentin with few dentin tubules. Compared to the Nfic KO tooth, which contains essentially no dentin tubules and remains in a “root-less” status at adult stages, the Osx cKO root phenotype had partially improved at the late stage, indicating that other factors can compensate for OSX function. Thus, we conclude that OSX, one of the key downstream molecules of NFIC, plays a critical role in root, but not crown, formation. PMID:25349111

  19. Microstructure and wettability of root canal dentine and root canal filling materials after different chemical irrigation

    NASA Astrophysics Data System (ADS)

    Antonijevic, Djordje; Milovanovic, Petar; Brajkovic, Denis; Ilic, Dragan; Hahn, Michael; Amling, Michael; Rakocevic, Zlatko; Djuric, Marija; Busse, Björn

    2015-11-01

    The objective of this study was to determine the effects of various irrigation solutions on root canal dentine and gutta-percha surface properties. In addition, the effects of disinfectant chemicals on the wettability and surface morphological properties of the filling materials were evaluated. Ethylenediaminetetraacetic acid (EDTA), citric acid, and ozone were employed as irrigation solutions for dentine and gutta-percha treatment. Thereafter, the samples' microstructure, degree of mineralization, and mechanical properties were assessed by means of quantitative backscattered electron imaging (qBEI) and reference point indentation (RPI). A contact angle analyzer was used to measure adhesion on the tested materials. Here, EDTA had the most significant affect on both the mechanical properties and the adhesive behavior of dentine. Citric acid did not affect dentine wettability, whereas the indentation properties and the mineralization were reduced. Similar effects were observed when ozone was used. The dentinal tubules were significantly widened in citric acid compared to the ozone group. EDTA causes considerable micromechanical surface alteration of dentine and gutta-percha, but represents the best option in clinical cases where a high adhesiveness of the filling materials is desired.

  20. Tooth root dentin mineralization defects in a mouse model of hypophosphatasia

    PubMed Central

    Foster, B.L.; Nagatomo, K.J.; Tso, H.W.; Tran, A.B.; Nociti, F.H.; Narisawa, S.; Yadav, M.C.; McKee, M.D.; Millán, J.L.; Somerman, M.J.

    2012-01-01

    Tissue-nonspecific alkaline phosphatase (TNAP) is expressed in mineralizing tissues and functions to reduce pyrophosphate (PPi), a potent inhibitor of mineralization. Loss of TNAP function causes hypophosphatasia (HPP), a heritable disorder marked by increased PPi, resulting in rickets and osteomalacia. Tooth root cementum defects are well described in both HPP patients and in Alpl−/− mice, a model for infantile HPP. In Alpl−/− mice, dentin mineralization is specifically delayed in the root, however, reports from human HPP patients are variable and inconsistent regarding dentin defects. In the present study, we aimed to define the molecular basis for changes in dentinogenesis observed in Alpl−/− mice. TNAP was found to be highly expressed by mature odontoblasts, and Alpl−/− molar and incisor roots featured defective dentin mineralization, ranging from a mild delay to severely disturbed root dentinogenesis. Lack of mantle dentin mineralization was associated with disordered and dysmorphic odontoblasts having disrupted expression of marker genes osteocalcin and dentin sialophosphoprotein. The formation of, initiation of mineralization within, and rupture of matrix vesicles in Alpl−/− dentin matrix was not affected. Osteopontin (OPN), an inhibitor of mineralization that contributes to the skeletal pathology in Alpl−/− mice, was present in the generally unmineralized Alpl−/− mantle dentin at ruptured mineralizing matrix vesicles, as detected by immunohistochemistry and by immunogold labeling. However, ablating the OPN-encoding Spp1 gene in Alpl−/− mice was insufficient to rescue the dentin mineralization defect. Administration of bioengineered mineral-targeting human TNAP (ENB-0040) to Alpl−/− mice corrected defective dentin mineralization in the molar roots. These studies reveal that TNAP participates in root dentin formation and confirm that reduction of PPi during dentinogenesis is necessary for odontoblast differentiation, dentin

  1. The surface of root canal irradiated by Nd:YAG laser with TiO2

    NASA Astrophysics Data System (ADS)

    Ebihara, Arata; Anjo, Tomoo; Takeda, Atsushi; Suda, Hideaki

    2004-05-01

    The aim of this study was to determine the appropriateness of Nd:YAG laser irradiation for root canal preparation. Tooth crowns were removed from single-rooted human teeth and a quartz optical fiber (diameter 400 μm) was inserted into the root canal orifice towards the apical foramen. The length of the fiber within the root canal was measured, and the irradiating length determined. Root canals were then filled with 3% TiO2 emulsion solution (a photosensitizer) and irradiated using a pulsed Nd:YAG laser at 600 mJ/pulse (pulse frequency; 5 or 10 pps). During laser irradiation, the fiber was moved coronally from the apical region towards the canal orifice at a rate of 1 mm/s. Contact microradiographs (CMR) were taken before and after laser irradiation. Each root was then halved longitudinally, and the root canal surface observed by scanning electron microscopy (SEM). The CMR images of the tooth revealed that the root canal was slightly enlarged as a result of treatment. Carbonization of the root canal dentin was not seen, but a smear layer and melted dentin were observed by SEM. Nd:YAG laser irradiation using TiO2 emulsion solution appears to be a useful tool for root canal preparation.

  2. Assessment of radicular dentin permeability after irradiation with CO2 laser and endodontic irrigation treatments with thermal imaging.

    PubMed

    Cho, Heajin; Lee, Robert C; Chan, Kenneth H; Fried, Daniel

    2017-01-28

    Previous studies have demonstrated that the permeability changes due to the surface modification of dentin can be quantified via thermal imaging during dehydration. The CO2 laser has been shown to remove the smear layer and disinfect root canals. Moreover, thermal modification via CO2 laser irradiation can be used to convert dentin into a highly mineralized enamel-like mineral. The purpose of this study is to evaluate the radicular dentin surface modification after CO2 laser irradiation by measuring the permeability with thermal imaging. Human molar specimens (n=12) were sectioned into 4 axial walls of the pulp chamber and treated with either 10% NaClO for 1 minute, 5% EDTA for 1 minute, CO2 laser or none. The CO2 laser was operated at 9.4 μm with a pulse duration of 26 μs, pulse repetition rate of 300 Hz and a fluence of 13 J/cm(2). The samples were dehydrated using an air spray for 60 seconds and imaged using a thermal camera. The resulting surface morphological changes were assessed using 3D digital microscopy. The images from digital microscopy confirmed melting of the mineral phase of dentin. The area enclosed by the time-temperature curve during dehydration, ΔQ, measured with thermal imaging increased significantly with treatments with EDTA and the CO2 laser (P<0.05). These results indicate that the surface modification due to CO2 laser treatment increases permeability of radicular dentin.

  3. Assessment of radicular dentin permeability after irradiation with CO2 laser and endodontic irrigation treatments with thermal imaging

    NASA Astrophysics Data System (ADS)

    Cho, Heajin; Lee, Robert C.; Chan, Kenneth H.; Fried, Daniel

    2017-02-01

    Previous studies have demonstrated that the permeability changes due to the surface modification of dentin can be quantified via thermal imaging during dehydration. The CO2 laser has been shown to remove the smear layer and disinfect root canals. Moreover, thermal modification via CO2 laser irradiation can be used to convert dentin into a highly mineralized enamel-like mineral. The purpose of this study is to evaluate the radicular dentin surface modification after CO2 laser irradiation by measuring the permeability with thermal imaging. Human molar specimens (n=12) were sectioned into 4 axial walls of the pulp chamber and treated with either 10% NaClO for 1 minute, 5% EDTA for 1 minute, CO2 laser or none. The CO2 laser was operated at 9.4 μm with a pulse duration of 26 μs, pulse repetition rate of 300 Hz and a fluence of 13 J/cm2. The samples were dehydrated using an air spray for 60 seconds and imaged using a thermal camera. The resulting surface morphological changes were assessed using 3D digital microscopy. The images from digital microscopy confirmed melting of the mineral phase of dentin. The area enclosed by the time-temperature curve during dehydration, ▵Q, measured with thermal imaging increased significantly with treatments with EDTA and the CO2 laser (P<0.05). These results indicate that the surface modification due to CO2 laser treatment increases permeability of radicular dentin.

  4. Bond strength of adhesive systems to Er,Cr:YSGG laser-irradiated dentin.

    PubMed

    Carvalho, Adriana Oliveira; Reis, Andr Figueiredo; de Oliveira, Marcelo Tavares; de Freitas, Patr Cia Moreira; Aranha, Ana Cec Lia Corr A; Eduardo, Carlos de Paula; Giannini, Marcelo

    2011-11-01

    The purpose of this study was to evaluate the effects of Er,Cr:YSGG laser irradiation and different adhesive procedures on bond strength of two bonding agents to dentin. Studies have shown that laser-irradiated dentinal tissue yields lower bond strengths than does nonirradiated dentin. In this study, different treatment methods of laser irradiating dentin were studied to enhance the bond strength of bonding agents to nonirradiated dentin. Third molars were wet ground with SiC until the occlusal flat dentin surface was exposed, and the teeth were randomly assigned to six groups (n=5). A two-step self-etching primer (Clearfil SE Bond, G1) and a two-step etch-and-rinse adhesive (Single Bond Plus, G2) were applied to the nonirradiated dentin surface according to manufacturer's instructions, as control groups. In G3 and G4, the same adhesives were applied after Er,Cr:YSGG laser irradiation, whereas in G5 and G6 adhesives were applied after Er,Cr:YSGG laser irradiation, phosphoric acid etching, and NaOCl deproteinization of etched dentin. The Er,Cr:YSGG laser worked at 2.78??m and the repetition rate was fixed at 20?Hz. Composite blocks were built on bonded surfaces and the teeth were stored for 24?h at 37?C. Restored teeth were vertically and serially sectioned to obtain bonded specimens for the bond strength test. Data were analyzed by two-way ANOVA and Tukey test (?=5%). Laser irradiation reduced bond strengths for the two adhesives, regardless of acid etching and deproteinization of dentin post-irradiation (p<0.05). The self-etching primer system showed higher bond strengths to laser irradiated dentin than did Single Bond Plus (p<0.05). The adhesive systems applied to normal dentin yielded higher bond strengths than when they were applied to laser irradiated dentin (p<0.05). The self-etching primer seemed to be less affected by dentin irradiation with Er,Cr:YSGG laser. The additional etching and NaOCl solution did not overcome the effects of laser irradiation on

  5. Essential role of osterix for tooth root but not crown dentin formation.

    PubMed

    Zhang, Hua; Jiang, Yong; Qin, Chunlin; Liu, Ying; Ho, Sunita P; Feng, Jian Q

    2015-04-01

    Tooth is made of crown and root. It is widely believed that dentin formation in crown and root uses the same regulatory mechanism. However, identification of nuclear factor 1 C (NFIC)'s unique function in determining root but not crown dentin formation challenges the old thinking. In searching for the target molecules downstream of NFIC, we unexpectedly found a sharp reduction of osterix (OSX), the key transcription factor in skeleton formation, in the Nfic knockout (Nfic-KO) tooth root. We then demonstrated a dose-dependent increase of Osx in the odontoblast cell line due to a transient transfection of Nfic expression plasmid. Studies of global and conditional Osx-KO mice revealed no apparent changes in the crown dentin tubules and dentin matrix. However, the OSX conditional KO (cKO) mice (crossed to the 2.3-kb collagen type 1 [Col1]-Cre) displayed an increase in cell proliferation but great decreases in expressions of root dentin matrix proteins (dentin matrix protein 1 [DMP1] and dentin sialophosphoprotein [DSPP]), leading to an inhibition in odontoblast differentiation, and short, thin root dentin with few dentin tubules. Compared to the Nfic-KO tooth, which contains essentially no dentin tubules and remains in a "root-less" status at adult stages, the Osx-cKO root phenotype had partially improved at the late stage, indicating that other factors can compensate for OSX function. Thus, we conclude that OSX, one of the key downstream molecules of NFIC, plays a critical role in root, but not crown, formation.

  6. Effect of Er:YAG and Nd:YAG lasers on the mineral content of root canal dentin.

    PubMed

    Topçuoğlu, Hüseyin Sinan; Köseoğlu, Mustafa

    2015-02-01

    The aim of this study was to assess the effect of two different laser systems on the mineral content of root canal dentin. Thirty-six single canal-extracted mandibular premolars were used in this study. The teeth were randomly divided into two groups of 18 teeth each and prepared with a master apical file #50. Dentin chips were obtained by Gates-Glidden burs and saved in Eppendorf tubes to serve as a control. Then, root canals were treated with a erbium:yttrium-aluminum-garnet or neodymium:yttrium-aluminum-garnet laser. Dentin chips were again obtained using Gates-Glidden. The levels of calcium (Ca), phosphorus (P), magnesium (Mg), sodium (Na), and potassium (K) in each specimen were measured by inductively coupled plasma-atomic emission spectrometry. Data were statistically analyzed by a Mann-Whitney U test. The changes in Ca, P, Mg, Ca, and K levels and the Ca/P ratio after laser irradiations were minimal and statistically not significant (p > 0.05). It was determined that the laser systems used in this study did not affect the mineral content of root canal dentin.

  7. Effect of different diode laser wavelengths on root dentin decontamination infected with Enterococcus faecalis.

    PubMed

    Borges, Caroline Cristina; Estrela, Carlos; Lopes, Fabiane Carneiro; Palma-Dibb, Regina Guenka; Pecora, Jesus Djalma; De Araújo Estrela, Cyntia Rodrigues; Sousa-Neto, Manoel Damião de

    2017-09-13

    The objective of this study was to evaluate the antibacterial effect and the ultrastructural alterations of diode laser with different wavelengths (808nm and 970nm) and its association with irrigating solutions (2.5% sodium hypochlorite and 2% chlorhexidine) in root dentin contaminated by a five days biofilm. Thirteen uniradicular teeth were sectioned into 100 dentin intraradicular blocks. Initially, the blocks were immersed for 5min in 17% EDTA and washed with distilled water for 5min, then samples were sterilized for 30min at 120°C. The dentin samples were inoculated with 0.1mL of E. faecalis suspension in 5mL BHI (Brain Heart Infusion) and incubated at 37°C for 5days. After contamination, the specimens were distributed into ten groups (n=10) according to surface treatment: GI - 5mL NaOCl 2.5%, GII - 5mL NaOCl 2.5%+808nm diode (0.1W for 20s), GIII - 5mL NaOCl 2.5%+970nm diode (0.5W for 4s), GIV - 808nm diode (0.1W for 20s), GV - 970nm diode (0.5W for 4s), GVI - CHX 2%, GVII - CHX 2%+808nm diode (0.1W for 20s), GVIII - CHX 2%+970nm diode (0.5W for 4s), GIX - positive control and GX - negative control. Bacterial growth was analyzed by turbidity and optical density of the growth medium by spectrophotometry (nm). Then, the specimens were processed for analysis ultrastructural changes of the dentin surface by SEM. The data was subject to the One-way ANOVA test. GI (77.5±12.1), GII (72.5±12.2), GIII (68.7±8.7), GV (68.3±8.7), GVI (62.0±5.5) and GVII (67.5±3.3) were statistically similar and statistically different from GIV (58.8±25.0), GVIII (59.2±4.0) and control groups (p<0.05). SEM analysis showed a modified amorphous organic matrix layer with melted intertubular dentin when dentin samples were irradiated with 970nm diode laser; erosion of the intertubular dentin in blocks submitted to 808nm diode laser irradiation; and an increased erosion of the intertubular dentin when 2.5% NaOCl was associated to the different wavelengths lasers. All the therapeutic

  8. In vitro evaluation of the effect of dietary acids and toothbrushing on human root dentin permeability.

    PubMed

    Zandim, Daniela Leal; Leite, Fabio Renato Manzolli; Sampaio, José Eduardo Cezar

    2010-03-01

    The purpose of this in vitro study was to quantify the alterations in human root dentin permeability after exposure to dietary acids and to evaluate the effect of toothbrushing after acid application. Extracted human third molars had their crowns sectioned above the CEJ, pulp tissue removed, and cervical root dentin exposed using a high-speed bur (approximately 1 mm in depth of substance loss). From each root fragment, one specimen was prepared. A total of 25 specimens were used and distributed randomly into five groups. The specimens were attached to a hydraulic pressure apparatus to evaluate the alterations of root dentin permeability after exposure to different acids. Dentin permeability was measured after the following sequential steps: (1) treatment with EDTA for 3 minutes to obtain the maximum permeability; (2) root planing to create a smear layer; (3) exposure to different acidic substances for 5 minutes (vinegar, cola drink, lemon juice, white wine, and orange juice); and (4) brushing for 3 minutes. All acidic substances increased dentin permeability after root planing. Lemon juice produced higher values for permeability when compared to the other substances (P = .009); moreover, orange juice showed similar results (P < .02) except when compared to vinegar (P = .12). Brushing right after acid exposure significantly reduced dentin permeability except in the vinegar group (P = .07). Under the experimental conditions, dietary acids increased root dentin permeability, and immediate brushing reduced permeability levels.

  9. Combined effect of fluoride varnish to Er:YAG or Nd:YAG laser on permeability of eroded root dentine.

    PubMed

    Chiga, Sandra; Toro, Carmen Victoria Torres; Lepri, Taísa Penazzo; Turssi, Cecília Petroso; Colucci, Vivian; Corona, Silmara Aparecida Milori

    2016-04-01

    This study evaluated the combined effect of fluoride varnish to Er:YAG or Nd:YAG laser on permeability of eroded root dentine. Sixty slabs of bovine root dentine (2×2×2mm) were eroded with citric acid 0.3% (pH 3.2) during 2h and then kept in artificial saliva during 24h. Specimens were randomly assigned in 6 groups (n=10), to receive the following treatments: fluoride varnish; fluoride varnish+Er:YAG laser; fluoride varnish+Nd:YAG laser; non-fluoride varnish; non-fluoride varnish+Er:YAG laser; non-fluoride varnish+Nd:YAG laser. The Er:YAG (100mJ, 3Hz) and Nd:YAG (70mJ, 15Hz) were applied for 10s. Specimens were subjected to further erosive challenges with citric acid 0.3% 4×/day, during 1min, for 5 days, remaining in artificial saliva between cycles. Dentin permeability was then assessed. Two-way ANOVA demonstrated no significant interaction between laser and varnish (p=0.858). No effect was also detected for the main factor varnish (p=0.768), while permeability of eroded root dentin was significantly lower when such substrate was laser-irradiated, no matter the laser source (p<0.001). This study concluded that Er:YAG and Nd:YAG lasers can be employed to control the permeability of eroded root dentin, regardless of fluoride varnish application. Copyright © 2016. Published by Elsevier Ltd.

  10. Bactericidal effect of a 980-nm diode laser in the root canal wall dentin of bovine teeth.

    PubMed

    Gutknecht, N; Franzen, R; Schippers, M; Lampert, F

    2004-02-01

    The aim of this in vitro study was to investigate the antibacterial depth effect of continuous wave laser irradiation with a wavelength of 980 nm in the root canal wall dentin of bovine teeth. The long-term success of an endodontic therapy often fails due to remaining bacteria in the root canal or dentin tubules, which cannot be sufficiently eliminated through the classical root canal preparation technique nor through rinsing solutions. A total of 102 slices of bovine root dentin of different thicknesses (100, 300 and 500 micro m) were prepared. The samples were inoculated from one side with 5 micro L of an enterococcus faecalis suspension of defined concentration. Four slices per slice thickness served as a control group; the rest of the 30 slices per thickness were subjected to laser irradiation - 10 each of these slices were irradiated with distal outputs of 1.75, 2.3, and 2.8 Watts (W). After drying them for 30 sec, the back of the inoculated dentin slice was irradiated for 32 seconds with a 200- micro m fiber optical waveguide under constant movement of the fibers. The remaining bacteria were then detached in NaCl under vibration. The eluate produced by this was - taking account of the degree of dilution - plated out on sheep blood agar plates. After 24 h of incubation, the grown bacterial colonies were able to be counted out and evaluated. By doing so, they were compared with the non-irradiated, but otherwise identically treated control group. With a slice thickness of 100 micro m, the 980-nm diode laser achieved a maximum bacterial reduction of 95% at 1.75 W, 96% at 2.3 W, and 97% at 2.8 W. With a slice thickness of 300 micro m, a maximum of 77% of the bacteria was destroyed at 1.75 W, 87% at 2.3 W, and 89% at 2.8 W. The maximum bacterial reduction with a slice thickness of 500 micro m was 57% at 1.75 W, 66% at 2.3 W, and 86% at 2.8 W. The results of this research show that the 980-nm diode laser can eliminate bacteria that have immigrated deep into the

  11. Effect of laser irradiation on the fluoride uptake of silver diamine fluoride treated dentine.

    PubMed

    Mei, May L; Ito, Leticia; Zhang, C F; Lo, Edward C M; Chu, C H

    2015-04-01

    This study aimed to evaluate the fluoride uptake of dentine treated with a 38 % silver diamine fluoride (SDF) solution and laser irradiation at sub-ablative energy levels. Fifteen human dentine slices were prepared and divided into four samples each. Four types of laser were chosen: CO2 (10,600 nm), Er:YAG (2,940 nm), Nd:YAG (1,064 nm) and Diode (810 nm). First, the four samples from 12 of the dentine slices were treated with SDF, and then irradiated by one of the four types of laser at three different settings. One sample was untreated and acted as a control. The setting that rendered the highest fluoride uptake was selected. Second, the remaining dentine slices were treated with SDF and irradiated by the four lasers with the selected settings. Fluoride uptake was assessed using Energy Dispersive X-ray Spectrometry at the dentine surface and up to 20 μm below the surface. The selected settings were CO2 irradiation at 1.0 W for 1 s, Er:YAG irradiation at 0.5 W for 20 s, Nd:YAG irradiation at 2.0 W for 1 s and diode irradiation at 3.0 W for 3 s. The fluoride content (weight %) at the dentine surface following CO2, Er:YAG, Nd:YAG and diode irradiation was 6.91 ± 3.15, 4.09 ± 1.19, 3.35 ± 2.29 and 1.73 ± 1.04, respectively. CO2 and Er:YAG irradiation resulted in higher fluoride uptake than Nd:YAG and diode irradiation at all levels (p < 0.05). CO2 laser and Er:YAG laser irradiation rendered higher fluoride uptake in the SDF-treated dentine than Nd:YAG laser and diode laser irradiation.

  12. An in-vitro evaluation of the effect of 980 nm diode laser irradiation on intra-canal dentin surface and dentinal tubule openings after biomechanical preparation: Scanning electron microscopic study

    PubMed Central

    Jhingan, Pulkit; Sandhu, Meera; Jindal, Garima; Goel, Deepti; Sachdev, Vinod

    2015-01-01

    Context: Very recently, diode laser has been used for disinfecting the root canals in endodontic treatment and increasing its success rate and longevity utilizing the thermal effect of laser on surrounding tissues. Aims: The aim of this study is to evaluate the effect of 980 nm laser irradiation on intra-canal dentin surface – scanning electron microscopic (SEM) - in-vitro study. Methods: A total of 40 single-rooted freshly extracted permanent teeth were collected. Teeth were sectioned at the cemento-enamel junction using diamond disc. Root canals of all samples were prepared using hand ProTaper, which were randomly assigned into two groups (n = 20 each). Group 1: Receiving no treatment after biomechanical preparation; Group 2: 980 nm diode laser-treated root canals. Teeth were prepared for SEM analysis to check the size of intra-canal dentinal tubule openings. Statistical Analysis Used: Data were analyzed using SPSS V.16 software and compared using Levene's and independent t-test. Results: On statistical analysis, width of intracanal dentinal tubule openings in Group 1 (control) was significantly higher than those observed in Group 2 (diode laser-treated) (P < 0.001). Conclusion: This study showed that the application of 980 nm diode laser on intra-radicular dentin resulted in ultrastructural alterations resulting in melting of dentin. PMID:26097338

  13. 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

  14. A study of the dentinal permeability of the pulp chamber floor of human lower molars with separate roots.

    PubMed

    Pécora, J D; Costa, W F; Maia Campos, G

    1990-01-01

    The permeability of the dentin of the pulp chamber floor of lower molars with separate roots was studied, after instrumentation of the root canals by manual or ultrasonic techniques. The dentinal permeability was evaluated by the degree of penetration of copper ions in the tissue and quantified by methods used in morphometry. None of the combinations of irrigating solution/instrumentation technique caused an increase in the permeability of dentinal tissue in the pulp chamber region, probably because the dentin is reparative dentin, which is more amorphous and less tubular than primary dentin.

  15. Photoactivation of curcumin and sodium hypochlorite to enhance antibiofilm efficacy in root canal dentin.

    PubMed

    Neelakantan, Prasanna; Cheng, Cheng Qing; Ravichandran, Vinoddhine; Mao, Teresa; Sriraman, Priyanka; Sridharan, Swetha; Subbarao, Chandana; Sharma, Subash; Kishen, Anil

    2015-03-01

    To test the effect of ultrasonic or light activated curcumin and sodium hypochlorite against Enterococcus faecalis biofilms in vitro. E. faecalis biofilms were grown within root canals (n=175) and divided into 7 groups (n=25). Group 1, sterile saline; group 2, 3% sodium hypochlorite; group 3, 3% sodium hypochlorite activated with ultrasonic files (30s cycles for 4min); group 4, 3% sodium hypochlorite irradiated with blue light (1200mw/cm(2) for 4min); group 5, curcumin (2.5mg/mL); group 6, curcumin (2.5mg/mL) activated with ultrasonic files (30s cycles for 4min); group 7, curcumin (2.5mg/mL) irradiated with blue light. The biofilms' ultrastructure was examined using scanning electron microscopy. Bacterial viability was assessed by confocal microscopy. Data were analyzed by one-way ANOVA and Student-Newman-Keuls test (P=0.05). The quantitative analysis of the colony-forming units was carried out from dentinal shaving and analyzed by One-way ANOVA and Tukey multiple comparison test (P=0.05). All treatment groups showed a significantly higher percentage of dead bacteria than the saline control (P<0.05). The percentage of dead bacteria was significantly higher when light activated curcumin was used (P<0.05). At both depths (200 and 400 microns), light activated curcumin showed no growth of bacteria. Light activation produced significantly higher antibacterial efficacy than ultrasonic agitation, with light activated curcumin producing the maximum elimination of biofilm bacteria within the root canal lumen and dentinal tubules. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Comparison of incidence of dentinal defects after root canal preparation with continuous rotation and reciprocating instrumentation.

    PubMed

    Monga, Prashant; Bajaj, Nitika; Mahajan, Pardeep; Garg, Shiwani

    2015-12-01

    Biomechanical preparation is one of the most important steps in endodontic therapy. Rotary instrumentation has facilitated this step. Nowadays the market is flooded with different types of rotary instruments. The present study compared the root dentinal crack formation with continuous rotating versus reciprocating root canal preparation methods. One hundred and fifty freshly extracted teeth were used for the study. They were divided into 5 groups with 30 teeth in each group. Thirty teeth were kept under control group A and no root canal preparation was done for this group. Another 30 teeth were prepared with hand files which were kept under control group B. In the experimental groups (sample size, n=30 each) root canals were prepared with ProTaper, K3XF rotary system and WaveOne. Sectioning of these teeth was done at 3, 6 and 9mm from the apex and were evaluated for the presence of any defects. Root dentinal cracks were produced with each type of rotary instruments. Statistical analysis showed no significant difference in root dentinal crack formation between control groups and WaveOne system. There was statistically significant difference in root dentinal crack formation when the canals were prepared with ProTaper and K3XF rotary system. So it was concluded, that continuous rotating instruments could produce dentinal crack formation. Root canal instruments with reciprocating movement appear to be a better option than continuous rotation movement.

  17. Biological effects of a root conditioning agent for dentin surface modification in vitro

    PubMed Central

    Lee, Jue-Yeon; Seol, Yang-Jo; Park, Jang-Ryul; Park, Yoon-Jeong

    2010-01-01

    Purpose Connective tissue reattachment to periodontally damaged root surfaces is one of the most important goals of periodontal therapy. The aim of this study was to develop a root conditioning agent that can demineralize and detoxify the infected root surface. Methods Dentin slices obtained from human teeth were treated with a novel root planing agent for 2 minutes and then washed with phosphate-buffered saline. Smear layer removal and type I collagen exposure were observed by scanning electron microscopy (SEM) and type I collagen immunostaining, respectively. Cell attachment and lipopolysaccharides (LPS) removal demonstrated the efficiency of the root conditioning agent. Results SEM revealed that the smear layer was entirely removed and the dentinal tubules were opened by the experimental gel. Type I collagen was exposed on the surfaces of the dentin slices treated by the experimental gel, which were compared with dentin treated with other root planing agents. Dentin slices treated with the experimental gel showed the highest number of attached fibroblasts and flattened cell morphology. The agar diffusion assay demonstrated that the experimental gel also has effective antimicrobial activity. Escherichia coli LPS were effectively removed from well plates by the experimental gel. Conclusions These results demonstrated that this experimental gel is a useful tool for root conditioning of infected root surfaces and can also be applied for detoxification of ailing implant surface threads. PMID:21246015

  18. Concurrent Effects of Bleaching Materials and the Size of Root Canal Preparation on Cervical Dentin Microhardness

    PubMed Central

    Kazemipoor, Maryam; Azad, Shaghayegh; Farahat, Farnaz

    2017-01-01

    Introduction: The aim of the present study was to evaluate the concurrent effect of root canal preparation size and intra coronal bleaching on dentin microhardness. Methods and Materials: Seventy-two intact anterior teeth were root canal treated and randomly divided into two groups (n=36) according to the size of coronal root canal preparation. The coronal portions of the canals were then enlarged with #2 and 4 Peeso reamers, respectively. Following root canal obturation, teeth were assigned into three groups (n=12) to be treated with bleaching agents containing 35% hydrogen peroxide (HP), sodium perborate (SP) and distilled water as control group. The teeth were stored at 37ºC and 100% humidity for 7 days. Dentinal blocks with 3 mm thickness were obtained from the cervical region and Vickers microhardness number (VHN) were measured for outer and inner dentin in each tooth sample. Data were analyzed using two-way ANOVA and Tukey’s HSD tests. Results: In the outer dentin, the mean VHN in the HP and control groups showed statistically significant differences (P=0.047). The mean VHN of inner dentin for the large preparation size was statistically higher in comparison to the small preparation size (P=0.042). There was a statistically significant difference in the mean VHN of inner dentin with small preparation size between HP and SP groups (P=0.029) and HP and control groups (P=0.021). Conclusion: Intra coronal bleaching with 35% hydrogen peroxide, affects the inner and outer dentin significantly. Excessive removal of cervical dentin, following root canal preparation, alongside the adverse effect of bleaching materials on dentin could result in the tooth fracture. PMID:28808454

  19. Concurrent Effects of Bleaching Materials and the Size of Root Canal Preparation on Cervical Dentin Microhardness.

    PubMed

    Kazemipoor, Maryam; Azad, Shaghayegh; Farahat, Farnaz

    2017-01-01

    The aim of the present study was to evaluate the concurrent effect of root canal preparation size and intra coronal bleaching on dentin microhardness. Seventy-two intact anterior teeth were root canal treated and randomly divided into two groups (n=36) according to the size of coronal root canal preparation. The coronal portions of the canals were then enlarged with #2 and 4 Peeso reamers, respectively. Following root canal obturation, teeth were assigned into three groups (n=12) to be treated with bleaching agents containing 35% hydrogen peroxide (HP), sodium perborate (SP) and distilled water as control group. The teeth were stored at 37(º)C and 100% humidity for 7 days. Dentinal blocks with 3 mm thickness were obtained from the cervical region and Vickers microhardness number (VHN) were measured for outer and inner dentin in each tooth sample. Data were analyzed using two-way ANOVA and Tukey's HSD tests. In the outer dentin, the mean VHN in the HP and control groups showed statistically significant differences (P=0.047). The mean VHN of inner dentin for the large preparation size was statistically higher in comparison to the small preparation size (P=0.042). There was a statistically significant difference in the mean VHN of inner dentin with small preparation size between HP and SP groups (P=0.029) and HP and control groups (P=0.021). Intra coronal bleaching with 35% hydrogen peroxide, affects the inner and outer dentin significantly. Excessive removal of cervical dentin, following root canal preparation, alongside the adverse effect of bleaching materials on dentin could result in the tooth fracture.

  20. Bactericidal effect of Er:YAG laser combined with sodium hypochlorite irrigation against Enterococcus faecalis deep inside dentinal tubules in experimentally infected root canals.

    PubMed

    Cheng, X; Chen, B; Qiu, J; He, W; Lv, H; Qu, T; Yu, Q; Tian, Y

    2016-02-01

    This study evaluated the bactericidal effect of Er:YAG laser radiation combined with sodium hypochlorite (NaOCl) irrigation in the treatment of Enterococcus faecalis deep inside dentinal tubules. The Er:YAG laser was activated, respectively, at 0.3, 0.5 and 1.0 W for either 20 or 30 s; 52.5 g l(-1) NaOCl and normal saline were used for the control groups. Root canals before and after treatments were examined using scanning electron microscopy (SEM). Bacterial reductions both on the root canal walls and at 100, 200, 300, 400 and 500 μm inside the dentinal tubules were analysed using a one-way analysis of variance. SEM results showed that the Er:YAG laser combined with NaOCl disinfected the dentinal tubules from 200 to over 500 μm depth as irradiation power and time increased. This combination killed significantly more bacteria than both the negative control group at each level tested and the positive control group at 300, 400 and 500 μm inside the dentinal tubules. It reached 100% in all experimental groups, both on the root canal walls and at 100 and 200 μm inside the dentinal tubules. However, at 300, 400 and 500 μm inside the dentinal tubules, only the groups treated with 0.5 and 1.0 W for 30s exhibited no bacterial growth. Of the two groups in which no bacteria were detected at all tested depths, Er:YAG laser irradiation at 0.5 W for 30 s combined with NaOCl irrigation was preferable because of the lower emission power and shorter irradiation time, and may serve as a new option for effective root canal disinfection.

  1. Adaptation and penetration of resin-based root canal sealers in root canals irradiated with high-intensity lasers

    NASA Astrophysics Data System (ADS)

    Moura-Netto, Cacio; Mello-Moura, Anna Carolina Volpi; Palo, Renato Miotto; Prokopowitsch, Igor; Pameijer, Cornelis H.; Marques, Marcia Martins

    2015-03-01

    This research analyzed the quality of resin-based sealer adaptation after intracanal laser irradiation. Extracted teeth (n=168) were root canal treated and divided into four groups, according to dentin surface treatment: no laser; Nd:YAG laser (1.5 W, 100 mJ, 15 Hz) diode laser (2.5 W in CW), and Er:YAG laser (1 W, 100 mJ, 10 Hz). The teeth were divided into four subgroups according to the sealer used: AH Plus, EndoREZ, Epiphany, and EpiphanySE. For testing the sealing after root canal obturation, the penetration of silver nitrate solution was measured, whereas to evaluate the adaptation and penetration of the sealer into the dentin, environmental scanning electron microscopy (ESEM) was used. The ESEM images were analyzed using a four-grade criteria score by three evaluators. The inter-examiner agreement was confirmed by Kappa test and the scores statistically compared by the Kruskal-Wallis' test (p<0.05). Both adaptation and sealer penetration in root canals were not affected by the laser irradiation. Nd:YAG and diode laser decreased the tracer penetration for AH Plus, whereas EndoREZ and EpiphanySE performances were affected by Nd:YAG irradiation (p<0.05). It can be concluded that intracanal laser irradiation can be used as an adjunct in endodontic treatment; however, the use of hydrophilic resin sealers should be avoided when root canals were irradiated with Nd:YAG laser.

  2. [Effect of Pinus massoniana needle extract on root dentin demineralization in vitro].

    PubMed

    Chengfang, Tang; Jianping, Ruan; Yong, Zhu; Zixia, Li; Yanping, Zuo; Hongyan, Xu

    2016-10-01

    This study aims to evaluate the effects of Pinus massoniana needle extract (PMNE) on inhibiting demineralization of root dentin. Root dentin blocks were randomly divided into distilled deionized water (DDW) group, fluoride sodium (NaF) group, and 4%, 8% and 12% PMNE groups according to the experimental solution used in the process of pH cycling in each group. All specimens in each group experienced pH cycling for 8 d. The dentin mineral density (DMD) of the normal dentin and demineralized dentin and their D-value (ΔDMD) were determined using micro computed tomography. The morphology of dentin surface after pH cycling was also observed using a scanning electron microscope. The ΔDMD values in all PMNE groups and the NaF group were considerably lower than the ΔDMD in the DDW group (P<0.05). The ΔDMD values of the 8% and 12% PMNE groups had no difference (P>0.05), both of which were lower than the ΔDMD in the 4% PMNE group and higher than that in the NaF group (P<0.05). The dentin tubules were partly opened in the PMNE groups. The opening degrees of the dentin tubule in PMNE groups were significantly less and smaller than the opening degree in the DDW group and were larger than that in the NaF group. PMNE can inhibit the deminera-lization of root dentin and can slow down the reduction in DMD. PMNE has the potential to prevent caries, and 8% PMNE can effectively inhibit dentin demineralization.

  3. Influence of different root canal-filling materials on the mechanical properties of root canal dentin.

    PubMed

    Grande, Nicola M; Plotino, Gianluca; Lavorgna, Luca; Ioppolo, Pietro; Bedini, Rossella; Pameijer, Cornelis H; Somma, Francesco

    2007-07-01

    The aims of this study were to compare Resilon (Resilon Research LLC, Madison, CT) in conjunction with either a bonding (Epiphany; Pentron Clinical Technologies, Wallingford, CT) or a nonbonding endodontic sealer (Pulp Canal Sealer; Kerr Corporation, Orange, CA) to EndoRez (Ultradent Products Inc, South Jordan, UT) and gutta-percha with regards to the physical properties and flexural stress in standardized dentin cylinders and the flexural stress of Resilon and gutta-percha. The external surface of 50 maxillary central incisors was reduced by means of mechanical milling to obtain dentin cylinders with an external diameter of 3 mm and minimum length of 12 mm. Root canals were prepared to obtain a standardized cylindrical preparation of 1.3 mm in diameter at the center of the root. The cylinders were randomly divided into five groups (n = 10): group 1: obturation with gutta-percha and Pulp Canal Sealer; group 2: obturation with Resilon, Epiphany primer, and Epiphany; group 3: obturation with Resilon and Pulp Canal Sealer; group 4: obturation with EndoRez methacrylate-based endodontic sealer; and group 5: dentin cylinders were not obturated. Ten gutta-percha (group 6) and Resilon (group 7) pellets for the Obtura gun were also tested. A three-point bending test was used to measure the maximum load values of specimens from groups 1 to 5 and the flexural strength and flexural modulus values for specimens from groups 6 and 7. Statistical analysis was performed to determine significance differences (p < 0.05). An analysis of variance test showed no significant difference among groups 1 to 5 (p = 0.697; F = 0.60). An independent sample t test showed statistically significant differences between groups 6 and 7 in flexural strength (p = 0.000) and flexural modulus (p = 0.000). Within the limits of this study, it may be concluded that the currently available endodontic-filling materials and their recommended adhesive procedures are not able to influence the mechanical

  4. Comparison of resin push-out strength to root dentin of bovine- and human-teeth.

    PubMed

    Galhano, Graziela; de Melo, Renata Marques; Valandro, Luiz Felipe; Bottino, Marco Antonio

    2009-01-01

    To compare the push-out strength of bovine- and human-root dentin and, thus, evaluate the suitability of bovine-root dentin to substitute human-root dentin for bond strength testing. Ten single-rooted human-teeth and ten bovine incisors were prepared using a #3 bur of a fiber post system (12 mm long). The posts were duplicated with resin cement (Duolink). The root canals were treated with All Bond 2 adhesive system and the resin posts were cemented using Duolink. The specimens were cut perpendicular to their long axis, yielding disc-specimens with 1.5 mm thickness, which were submitted to a push-out test (1 mm/min). Ten bond strength values per group (n = 10) were used for statistical analysis (Student t test, alpha =.05). Statistically significant differences were found for the bond strength values between bovine- (4.1 +/- 1.3 MPa) and human-root dentin (8.6 +/- 5.7 MPa) (P =.0001). The push-out strengths of bovine- and human-root dentin were statistically different.

  5. Effect of instrumentation with different irrigating solutions and with or without Er:YAG laser irradiation on radicular dentine permeability

    NASA Astrophysics Data System (ADS)

    Pecora, Jesus D.; Ribeiro, Rodrigo G.; Marchesan, Melissa A.; Brugnera, Aldo, Jr.

    2004-05-01

    This study evaluated radicular dentine permeability of root canal walls when using different irrigating solutions associated or not with Er:YAG laser. Fifty human maxillary incisors, obtained from laboratory stock, were randomly divided into ten groups of five teeth each. External surfaces of the teeth were impermeabilized with cyanoacrylate (Super Bonder). After chamber access, the root canals were instrumented with the step-back technique. Ten ml of irrigating solution was used in each root canal. Group I: irrigated with distilled and deionized water; Group II: irrigated as Group I and irradiated with laser; Group III: irrigated with 0.1% laurel diethyleneglycol ether sodium sulfate; Group IV: irrigated as Group III and irradiated with laser; Group V: irrigated with 1% sodium hypochlorite; Group VI: irrigated as Group V and irradiated with laser; Group VII: irrigated with 15% EDTA; Group VIII: irrigated as Group VII and irradiated with laser; Group IX: irrigated with 10% citric acid; Group X: irrigated as Group IX and irradiated with laser. Laser (KaVo Key Laser II) was applied with the following parameters: 15 Hz, 300 pulses, 42 J total energy, and 140mJ input and 51mJ ouput. The fiber optic tip was introduced until the apex and the laser was activated. The tip was withdrawn gently with helicoidally movement from the apex until the cervical portion. After preparation of the root canals, the root were immersed in 10% copper sulfate for 30 minute and then immersed in 1% rubeanic acid alcohol solution for the same period. The roots were sectioned transversally into 150μm slices, sanded, washed, dehydrated, cleared and mounted on glass slides for microscopic examination. The quantification of the penetration of copper ions was done by morphometric analysis. Results showed that distilled and deionized water + laser and 1% sodium hypochlorite presented the highest dentine permeability (p>0.05) and was statistically different from the other groups (p<0.05). The use of

  6. Effect of Peracetic Acid as A Final Rinse on Push Out Bond Strength of Root Canal Sealers to Root Dentin.

    PubMed

    Gaddala, Naresh; Veeramachineni, Chandrasekhar; Tummala, Muralidhar

    2015-05-01

    Smear layer which was formed during the instrumentation of root canals hinders the penetration of root canal sealers to root dentin and affect the bond strength of root canal sealers to root dentin. Final irrigant such as demineralizing agents are used to remove the inorganic portion of the smear layer. In the present study, peracetic acid used as a final rinse, to effect the bond strength of root canal sealers to root dentin. The purpose of the present study was to evaluate the efficacy of peracetic acid as a final irrigant on bond strength of root canal sealers to root dentin. Sixty six freshly extracted human single rooted mandibular premolars were used for this study. After decoronation the samples were instrumented with Protaper upto F3 and irrigated with 5.25% NaOcl. The teeth were then divided into three groups based on final irrigant used: Group-1(control group) Canals were irrigated with distilled water. Group-2: Canals were irrigated with peracetic acid. Group-3: Canals were irrigated with smear clear. Each group was further divided into three subgroups (n=30) based on the sealer used to obturate the canals. Subgroup-1: kerr, Subgroup-2: Apexit plus, Subgroup-3: AH PLUS. Each sealer was mixed and coated to master cone and placed in the canal. The bonding between sealer and dentin surface was evaluated using push out bond strength by universal testing machine. The mean bond strength values of each group were statistically evaluated using Two-way ANOVA followed by Tukey post-hoc test. Significant difference was found among the bond strength of the sealers. But, there is no statistically significant difference between the groups irrigated with peracetic acid and smear clear compared to control group. AH Plus showed highest bond strength irrespective of the final irrigant used. Peracetic acid when employed as final irrigant improved the bond strength of root canal sealers compared to control group but not statistically significant than smear clear.

  7. Study on the potential inhibition of root dentine wear adjacent to fluoride-containing restorations.

    PubMed

    Turssi, Cecilia Pedroso; Hara, Anderson Takeo; Domiciano, Silvia Jorge; Serra, Mônica Campos

    2008-01-01

    The purpose of this in vitro study was to determine whether the vicinity of root dentine that had been restored with fluoride-releasing materials was at reduced risk for erosive/abrasive wear compared to root dentine restored with a non-fluoride-containing material. According to a randomized complete block design, standardized cavities prepared on the surface of 150 bovine root dentine slabs were restored with glass-ionomer cement, resin-modified glass ionomer, polyacid-modified resin composite, fluoride-containing or conventional composite. Specimens were coated with two layers of an acid-resistant nail varnish exposing half of the dentine surface and half of the restoration. Subsequently, specimens were either eroded in an acidic drink or left uneroded, then exposed to artificial saliva and abraded in a toothbrushing machine. Wear depth in the vicinity of restorations was quantified by a stylus profilometer, based on the nonabraded areas surrounding the erosion/abrasion region. Two-way ANOVA did not demonstrate significant interaction between restoratives and eroded-uneroded dentine (p=0.5549) nor significant difference among restorative materials (p=0.8639). Tukey's test ascertained that the wear depth was higher for eroded than for uneroded groups. Fluoride-releasing materials seemed to negligibly inhibit wear in the vicinity of restored root dentine subjected to erosive/abrasive challenges.

  8. Comparison between water and ethanol wet bonding of resin composite to root canal dentin.

    PubMed

    Sauro, Salvatore; Di Renzo, Simona; Castagnola, Raffaella; Grande, Nicola M; Plotino, Gianluca; Foschi, Federico; Mannocci, Francesco

    2011-02-01

    To evaluate the bond strength of resin dentin interfaces created with adhesives applied on root dentin using the water wet or ethanol wet bonding technique. The morphology of resin dentin interfaces was evaluated using confocal microscopy. Four experimental resin adhesives (R#A to R#D) and one commercial three-step/etch and rinse adhesive were applied to the root canal dentin of endodontically treated single canal incisors using the water (control) or ethanol wet bonding technique. The ethanol wet bonding substrate was achieved by keeping the root canal immersed in absolute ethanol (100%) for 3 minutes. The root dentin bonded specimens were sectioned into beams, stored in distilled water (24 hours) and finally tested for microtensile bond strengths (tTBS). Additional dentin surfaces were conditioned and bonded as previously described. They were prepared for the microscopy study and finally observed using confocal microscopy. The ethanol wet bonding technique gave higher bond strength values for all the adhesives tested: in Group 1 (water wet bonding technique) no significant difference was found between the resins tested; the only exception being the most hydrophilic Resin #4 showing the highest bond strength values (P < 0.05). In Group 2 (ethanol wet bonding technique) no statistical differences were present between Resin #A and Resin #D. Resin #C showed the highest bond strength values. Confocal microscopy showed better resin diffusion and hybrid layer formation when the ethanol wet bonding was used.

  9. Wntless Regulates Dentin Apposition and Root Elongation in the Mandibular Molar

    PubMed Central

    Bae, C.H.; Kim, T.H.; Ko, S.O.; Lee, J.C.; Yang, X.

    2015-01-01

    Wnt signaling plays an essential role in the dental epithelium and mesenchyme during tooth morphogenesis. However, it remains unclear if Wnt ligands, produced from dental mesenchyme, are necessary for odontoblast differentiation and dentin formation. Here, we show that odontoblast-specific disruption of Wntless (Wls), a chaperon protein that regulates Wnt sorting and secretion, leads to severe defects in dentin formation and root elongation. Dentin thickness decreased remarkably and pulp chambers enlarged in the mandibular molars of OC-Cre;WlsCO/CO mice. Although the initial odontoblast differentiation was normal in the mutant crown, odontoblasts became cuboidal and dentin thickness was reduced. In immunohistochemistry, Wnt10a, β-catenin, type I collagen, and dentin sialoprotein were significantly down-regulated in the odontoblasts of mutant crown. In addition, roots were short and root canals were widened. Cell proliferation was reduced in the developing root apex of mutant molars. Furthermore, Wnt10a and Axin2 expression was remarkably decreased in the odontoblasts of mutant roots. Deletion of the Wls gene in odontoblasts appears to reduce canonical Wnt activity, leading to inhibition of odontoblast maturation and root elongation. PMID:25595365

  10. Wntless regulates dentin apposition and root elongation in the mandibular molar.

    PubMed

    Bae, C H; Kim, T H; Ko, S O; Lee, J C; Yang, X; Cho, E S

    2015-03-01

    Wnt signaling plays an essential role in the dental epithelium and mesenchyme during tooth morphogenesis. However, it remains unclear if Wnt ligands, produced from dental mesenchyme, are necessary for odontoblast differentiation and dentin formation. Here, we show that odontoblast-specific disruption of Wntless (Wls), a chaperon protein that regulates Wnt sorting and secretion, leads to severe defects in dentin formation and root elongation. Dentin thickness decreased remarkably and pulp chambers enlarged in the mandibular molars of OC-Cre;Wls(CO/CO) mice. Although the initial odontoblast differentiation was normal in the mutant crown, odontoblasts became cuboidal and dentin thickness was reduced. In immunohistochemistry, Wnt10a, β-catenin, type I collagen, and dentin sialoprotein were significantly down-regulated in the odontoblasts of mutant crown. In addition, roots were short and root canals were widened. Cell proliferation was reduced in the developing root apex of mutant molars. Furthermore, Wnt10a and Axin2 expression was remarkably decreased in the odontoblasts of mutant roots. Deletion of the Wls gene in odontoblasts appears to reduce canonical Wnt activity, leading to inhibition of odontoblast maturation and root elongation.

  11. Comparative study of dentine permeability after apicectomy and surface treatment with 9.6 microm TEA CO2 and Er:YAG laser irradiation.

    PubMed

    Gouw-Soares, S; Stabholz, A; Lage-Marques, J L; Zezell, D M; Groth, E B; Eduardo, C P

    2004-04-01

    Failure of apicectomies is generally attributed to dentine surface permeability as well as to the lack of an adequate marginal sealing of the retrofilling material, which allows the percolation of microorganisms and their products from the root canal system to the periodontal region, thus compromising periapical healing. The purpose of this study was to evaluate dentine and the marginal permeability after apicectomy and surface treatment with 9.6 micro m TEA CO(2) or Er:YAG 2.94 micro m laser irradiation. Sixty-five single rooted human endodontically treated teeth were divided into five experimental groups: group I (control), apicectomy with high speed bur; group II, similar procedure to that of group I, followed by dentinal surface treatment with 9.6 micro m CO(2) laser; group III, similar procedure to group I followed by dentinal surface treatment with Er:YAG laser 2.94 micro m; group IV, apicectomy and surface treatment with CO(2) 9.6 micro m laser; and group V, apicectomy and surface treatment with Er:YAG laser 2.94 micro m. The analysis of methylene blue dye infiltration through the dentinal surface and the retrofilling material demonstrated that the samples from the groups that were irradiated with the lasers showed significantly lower infiltration indexes than the ones from the control group. These results were compatible with the structural morphological changes evidenced through SEM analysis. Samples from groups II and IV (9.6 micro m CO(2)) showed clean smooth surfaces, fusion, and recrystallized dentine distributed homogeneously throughout the irradiated area sealing the dentinal tubules. Samples from groups III and V (Er:YAG 2.94 micro m) also presented clean surfaces, without smear layer, but roughly compatible to the ablationed dentine and without evidence of dentinal tubules. Through the conditions of this study, the Er:YAG 2.94 micro m and the 9.6 micro m CO(2) laser used for root canal resection and dentine surface treatment showed a reduction of

  12. Effect of final irrigation protocols on microhardness reduction and erosion of root canal dentin.

    PubMed

    Baldasso, Flávia Emi Razera; Roleto, Luana; Silva, Vinicius Duval da; Morgental, Renata Dornelles; Kopper, Patrícia Maria Poli

    2017-05-15

    This study aimed to evaluate the effect of final irrigation protocols on microhardness reduction and erosion of root canal dentin. Sixty root canals from mandibular incisors were instrumented and randomly divided into six groups (n = 10) according to the irrigant used: QMiX, 17% EDTA, 10% citric acid (CA), 1% peracetic acid (PA), 2.5% NaOCl (solution control), and distilled water (negative control). The chelating solutions were used to irrigate the canal followed by 2.5% NaOCl as a final flush. After the irrigation protocols, all specimens were rinsed with 10 mL of distilled water to remove any residue of the chemical solutions. Before and after the final irrigation protocols, dentin microhardness was measured with a Knoop indenter. Three indentations were made at 100 µm and 500 µm from the root canal lumen. Afterwards, the specimens were prepared for scanning electron microscopic analysis and the amount of dentin erosion was examined. Wilcoxon and Kruskal-Wallis tests were used to analyze the results with a significance level set at 5%. At 100 µm, all protocols significantly reduced dentin microhardness (p < .05), while at 500 µm, this effect was detected only in the EDTA and QMiX groups (p < .05). CA was the irrigant that caused more extensive erosion in dentinal tubules, followed by PA and EDTA. QMiX opened dentinal tubules, but did not cause dentin erosion. Results suggest that QMiX and 17% EDTA reduced dentin microhardness at a greater depth. Additionally, QMiX did not cause dentin erosion.

  13. Age Estimation by Assessment of Dentin Translucency in Single Rooted Permanent Teeth

    PubMed Central

    Kattappagari, Kiran Kumar; Kommalapati, Radhika Kalyani; Katuri, Deepthi; Murakonda, Raja Sekhar; Chitturi, Ravi Teja; Reddy, Baddam Venkat Ramana

    2014-01-01

    Background: To estimate the age by evaluating the area and length of dentin translucency in single-rooted ground sections of extracted teeth using digital Vernier caliper and stereomicroscope. Materials and Methods: Ground sections of single rooted permanent anterior teeth were made and stained with 1% methylene blue. The area and length of dentin translucency were measured using digital Vernier caliper and with the help of stereomicroscope. Results: Linear regressive analysis showed that estimation of age by assessing the area of dentin translucency with Vernier caliper was statistically significant and showed a high regression co-efficient (R = 0.7738) when compared to evaluation of age by assessment of length. Multilinear regressive analysis done to calculate age by both area and length also showed a high co-efficient of regression (R = 0.7797). Conclusion: The area of dentin translucency showed good correlation with age when compared to the length. PMID:25628481

  14. Residual Microstrain in Root Dentin after Canal Instrumentation Measured with Digital Moiré Interferometry.

    PubMed

    Lim, Helena; Li, Fang-Chi; Friedman, Shimon; Kishen, Anil

    2016-09-01

    Residual microstrain influences the resistance to crack propagation in a biomaterial. This study evaluated the residual microstrain and microdefects formed in dentin after canal instrumentation in teeth maintained in hydrated and nonhydrated environments. Canals of 18 extracted human premolars with single-root canals were instrumented in accordance with 3 groups: the ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland) group: ProTaper Universal (S1, S2, F1, and F2) used in rotation, the WaveOne Primary (Dentsply Maillefer) group: the WaveOne (Primary) used in reciprocal motion, and the control group: hand files. Half the specimens (3/group) were maintained in deionized water (hydrated) and half in ambient relative humidity conditions (22°C, 55% RH) for 72 hours (nonhydrated). Customized high-sensitivity digital moiré interferometry was used to qualitatively evaluate pre- and postinstrumentation dentinal microstrain. Subsequently, specimens were examined for dentinal microdefects with micro-computed tomographic imaging and polarized light microscopy. Digital moiré interferometry showed only minor changes in postinstrumentation microstrain in hydrated dentin in all groups, suggestive of a stress relaxation behavior. Nonhydrated dentin in all groups showed localized concentration of postinstrumentation microstrain, which appeared higher in the WaveOne group than in the other groups. No dentinal microdefects were detected by micro-computed tomographic imaging and polarized light microscopy in hydrated and nonhydrated specimens in all groups. This study suggested that the biomechanical response of root dentin to instrumentation was influenced by hydration. Reciprocating, rotary, and hand instrumentation of well-hydrated roots did not cause an increase in residual microstrain or the formation of microdefects in root dentin. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  15. Effect of fluoridated milk on enamel and root dentin demineralization evaluated by a biofilm caries model.

    PubMed

    Giacaman, R A; Muñoz, M J; Ccahuana-Vasquez, R A; Muñoz-Sandoval, C; Cury, J A

    2012-01-01

    Although some studies suggest an anticaries effect of fluoridated bovine milk (F-milk) on enamel, evidence is still considered weak. Even more uncertain, the effect of F-milk on root caries remains largely unknown. This study evaluated the effect of F-milk on enamel and on root dentin demineralization using a validated Streptococcus mutans biofilm model, simulating a high cariogenic challenge. S. mutans (UA159) biofilms were formed on bovine enamel and root dentin saliva-coated slabs after measuring initial surface microhardness (SH). Biofilms were exposed to 10% sucrose 8×/day and treated 2×/day with either: (1) 0.9% NaCl (negative control), (2) bovine milk, (3) F-milk (5.0 ppm F as NaF) or (4) NaF 0.05% (anticaries-positive control). Medium pH was monitored twice/day, as a biofilm acidogenicity indicator. After 5 days for enamel and 4 days for dentin, biofilms were recovered to analyze: biomass, soluble proteins, viable microorganisms, and extra- and intracellular polysaccharides. Enamel and dentin demineralization were estimated by percentage of SH loss. Results were compared by ANOVA and Tukey's test. Neither acidogenicity nor biofilm composition differed among treatment groups in biofilms formed on enamel or dentin (p > 0.05). F-milk, however, significantly reduced enamel and dentin demineralization when compared with the negative control (p < 0.05). Also, F-milk was as efficient as 0.05% NaF to reduce enamel (p > 0.05), but not dentin demineralization (p < 0.05). These findings suggest that milk containing 5.0 ppm of fluoride is effective to control enamel caries and that it may be effective on root dentin caries prevention. Copyright © 2012 S. Karger AG, Basel.

  16. Lack of causal relationship between dentinal microcracks and root canal preparation with reciprocation systems.

    PubMed

    De-Deus, Gustavo; Silva, Emmanuel João Nogueira Leal; Marins, Juliana; Souza, Erick; Neves, Aline de Almeida; Gonçalves Belladonna, Felipe; Alves, Haimon; Lopes, Ricardo Tadeu; Versiani, Marco Aurélio

    2014-09-01

    This study aimed to evaluate the frequency of dentinal microcracks observed after root canal preparation with 2 reciprocating and a conventional full-sequence rotary system using micro-computed tomographic analysis. Thirty mesial roots of mandibular molars presenting a type II Vertucci canal configuration were scanned at an isotropic resolution of 14.16 μm. The sample was randomly assigned to 3 experimental groups (n = 10) according to the system used for the root canal preparation: group A-Reciproc (VDW, Munich, Germany), group B-WaveOne (Dentsply Maillefer, Baillagues, Switzerland), and group C-BioRaCe (FKG Dentaire, La-Chaux-de-Fonds, Switzerland). Second and third scans were taken after the root canals were prepared with instruments sizes 25 and 40, respectively. Then, pre- and postoperative cross-section images of the roots (N = 65,340) were screened to identify the presence of dentinal defects. Dentinal microcracks were observed in 8.72% (n = 5697), 11.01% (n = 7197), and 7.91% (n = 5169) of the cross-sections from groups A (Reciproc), B (WaveOne), and C (BioRaCe), respectively. All dentinal defects identified in the postoperative cross-sections were also observed in the corresponding preoperative images. No causal relationship between dentinal microcrack formation and canal preparation procedures with Reciproc, WaveOne, and BioRaCe systems was observed. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  17. Effect of Chloroform, Eucalyptol and Orange Oil Solvents on the Microhardness of Human Root Dentin

    PubMed Central

    Khedmat, Sedigheh; Hashemi, Alaleh; Dibaji, Fatemeh; Kharrazifard, Mohammad Javad

    2015-01-01

    Objectives: This study aimed to assess the effect of chloroform, eucalyptol and orange oil solvents on the microhardness of human root dentin. Materials and Methods: Sixty-eight single-rooted single-canal extracted human premolar teeth were used. Tooth crowns were separated from the roots at the cementoenamel junction (CEJ). Roots were buccolingually sectioned into mesial and distal halves. Specimens were randomly divided into 5 groups, with 20 teeth in each solvent group and 4 teeth in each control group. Primary microhardness of specimens was measured using Vickers microhardness tester. Specimens were exposed to solvents for 15 minutes and were subjected to microhardness testing again. Data were recorded and analyzed using repeated measure ANOVA. Results: No significant difference was found in dentin microhardness before and after exposure to solvents in any of the orange oil, eucalyptol, chloroform or saline groups (P=0.727). None of the experimental groups showed any significant difference in terms of dentin microhardness reduction (P=0.99) and had no significant difference with the negative control group. Conclusion: This study showed that chloroform, eucalyptol and orange oil as gutta percha solvents did not decrease the microhardness of root dentin. Thus, none of the mentioned solvents has any superiority over the others in terms of affecting dentin properties. PMID:26005451

  18. Effect of QMix irrigant on bond strength of glass fibre posts to root dentine.

    PubMed

    Elnaghy, A M

    2014-03-01

    To investigate the effect of QMix irrigant compared with several other irrigating solutions on the bond strength of glass fibre posts to root dentine and on smear layer removal after post space preparation. One hundred and fifty single-rooted teeth were used. The specimens were divided into six groups in each test according to the irrigation regimen used: group 1, distilled water; group 2, 5.25% sodium hypochlorite (NaOCl); group 3, 2% chlorhexidine digluconate (CHX); group 4, 17% ethylenediaminetetraacetic acid (EDTA); group 5, 17% EDTA followed by 2% CHX; and group 6, QMix. Dual-cure self-adhesive resin cement (i CEM; Heraeus Kulzer, Hanau, Germany) was used for testing the adhesion of glass fibre post (Reblida; VOCO, Cuxhaven, Germany) to root dentine using a micropush-out test. Debonding specimens were examined with a scanning electron microscope. Scanning electron microscopy was also used to examine and score the treated specimens for debris removal and dentinal tubule opening. Micropush-out data were analysed using anova and Tukey's test. Debris and dentinal tubule opening scores were analysed with the Kruskal-Wallis and Mann-Whitney U-tests. QMix and 17% EDTA/2% CHX demonstrated the highest mean bond strength values in all root levels amongst the groups. Most failure modes were adhesive type of failures between post and luting material (42.6%). QMix, 17% EDTA and 17% EDTA/2% CHX performed significantly better than the other groups on smear layer removal and dentinal tubule opening. QMix is an effective irrigant that can remove smear layer, open dentinal tubules and simplify the irrigation protocol, without compromising the bonding strength of glass fibre posts cemented with a self-adhesive resin cement to root dentine. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  19. [Temperature variation at the external root surface during Nd: YAG laser irradiation in the root canal in vitro].

    PubMed

    Yuan-Gao, Li; Xiao, Wang; Kexian, Xie; Dan, Liu

    2014-10-01

    To assess the temperature variation of the root surface using Nd: YAG laser irradiation in the root canal with different power and to evaluate the safety of laser application on the periodontal region. Thirty extracted human teeth with single-roots were collected. The teeth were cross-sectioned in the cervical portion, standardizing the roots at a 12-mm length. The roots were used as specimen. The roots were radiographed in the buccal-lingual direction to measure the thickness of the proximal walls, by means of a digital radiographic system. The specimens were divided into three groups according to the laser potency (1.5, 3.0, and 4.5 W). Each group was subdivided into two subgroups according to laser frequency (15 and 30 Hz). With the Nd: YAG laser irradiation for 20 s, the temperature variation of the root surface was monitored by thermocouples located at different parts of the root external wall and recorded by digital thermometers. The groups irradiated with 4.5 W presented the greatest temperature variation (above 10°C), followed by 3.0 and 1.5 W. The temperatures were statistically different (P < 0.01). The groups irradiated in the same potency, regardless of whether 15 Hz or 30 Hz was used, presented with no statistical difference (P > 0.05). The apical half of the root presented statistically higher temperature rises than the cervical half of the root (P < 0.01). The temperature variation of the root surface was associated with laser power, irradiation time, and the thickness of dentin. Application of Nd: YAG laser in the root at 1.5 W for 20 s can safely be used in endodontic treatment.

  20. Effect of root-canal sealer on the bond strength of fiberglass post to root dentin.

    PubMed

    Cecchin, Doglas; Farina, Ana Paula; Souza, Matheus Albino; Pereira, Charles Da Cunha

    2011-03-01

    To evaluate the effects of different root-canal sealers on the bond strength of a fiberglass post cemented with self-adhesive resin cements. Forty extracted maxillary single-rooted canines were prepared with the crown-down technique and randomly divided into four groups according to the tested sealer: Group 1: control group, gutta-percha cone only (no sealer); Group 2: EndoREZ; Group 3: Sealapex; Group 4: Endofill. The roots were obturated with the gutta-percha cone using the cold lateral compaction technique. Fiberglass posts were cemented into the prepared post spaces with the self-adhesive cement RelyX Unicem. Bonded specimens were sectioned into 1-mm thick slabs and a push-out test was performed in a universal machine. Data were subjected to ANOVA and Tukey tests (α = 0.05). No significant difference was detected between Groups 1-3 (P > 0.05). Group 4 showed a lower bond strength than the other sealers (P < 0.05). Endofill negatively interfered with the bond to root dentine; however, EndoRez and Sealapex did not affect the bond strength of the fiberglass post cemented with self-adhesive resin cements.

  1. The effect of fluoride toothpaste on root dentine demineralization progression: a pilot study.

    PubMed

    Botelho, Juliana Nunes; Del Bel Cury, Altair Antoninha; Silva, Wander Jose da; Tenuta, Livia Maria Andalo; Cury, Jaime Aparecido

    2014-01-01

    The anticaries effect of fluoride (F) toothpaste containing 1100 µg F/g in reducing enamel demineralization is well established, but its effect on dentine has not been extensively studied. Furthermore, it has been shown that toothpaste containing a high F concentration is necessary to remineralize root dentine lesions, suggesting that a 1100 µg F/g concentration might not be high enough to reduce root dentine demineralization, particularly when dentine is subjected to a high cariogenic challenge. Thus, the aim of this pilot study was to evaluate in situ the effect of F toothpaste, at a concentration of 1100 µg F/g, on dentine demineralization. In a crossover and double-blind study, conducted in two phases of 14 days, six volunteers wore a palatal appliance containing four slabs of bovine root dentine whose surface hardness (SH) was previously determined and to which a 10% sucrose solution was applied extra-orally 8×/day. Volunteers used a non-F toothpaste (negative control) or F toothpaste (1100 µg F/g, NaF/SiO2) three times a day. On the 10th and 14th days of each phase, two slabs were collected and SH was determined again. Dentine demineralization was assessed as percentage of SH loss (%SHL). The effect of toothpaste was significant, showing lower %SHL for the F toothpaste group (42.0 ± 9.7) compared to the non-F group (62.0 ± 6.4; p < 0.0001), but the effect of time was not significant (p > 0.05). This pilot study suggests that F toothpaste at 1100 µg F/g is able to decrease dentine caries even under a high cariogenic challenge of biofilm accumulation and sugar exposure.

  2. Effect of Imidazolium-Based Silver Nanoparticles on Root Dentin Roughness in Comparison with Three Common Root Canal Irrigants

    PubMed Central

    Farshad, Melika; Abbaszadegan, Abbas; Ghahramani, Yasamin; Jamshidzadeh, Akram

    2017-01-01

    Introduction: The aim of this study was to evaluate the effect of a nanosilver-based irrigant on dentin roughness in comparison with three commonly used root canal irrigation solutions. Methods and Materials: Three common irrigants including 5.25% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA) and 2% chlorhexidine (CHX) and also an imidazolium-based silver nanoparticle solution (ImSNP) (5.7×10 -8 mol/L), were used. Distilled water was used as control. Roots of 25 human anterior teeth were sectioned longitudinally to obtain 50 dentin samples. Roughness values were evaluated by atomic force microscopy analysis on 5 groups (n=10) after each group was treated in one of the tested irrigant solutions for 10 min. Values were statistically analyzed by One-way analysis of variance, followed by a post hoc Tukey’s test for pair-wise comparison. Results: Dentin roughness significantly increased from 95.82 nm (control) to 136.02 nm, 187.07 nm, 142.29 nm and 150.92 nm with NaOCl, CHX, ImSNP and EDTA, respectively. CHX demonstrated a significantly higher roughness value compared to the other tested irrigants while no significant differences were seen in NaOCl, ImSNP and EDTA groups (P>0.242). Conclusion: ImSNP affected the physicochemical properties of dentin and raised its surface roughness; thus, this irrigant could impact bacterial and restorative material adhesion to root canal dentin walls. PMID:28179931

  3. Effect of Imidazolium-Based Silver Nanoparticles on Root Dentin Roughness in Comparison with Three Common Root Canal Irrigants.

    PubMed

    Farshad, Melika; Abbaszadegan, Abbas; Ghahramani, Yasamin; Jamshidzadeh, Akram

    2017-01-01

    The aim of this study was to evaluate the effect of a nanosilver-based irrigant on dentin roughness in comparison with three commonly used root canal irrigation solutions. Three common irrigants including 5.25% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA) and 2% chlorhexidine (CHX) and also an imidazolium-based silver nanoparticle solution (ImSNP) (5.7×10 (-8) mol/L), were used. Distilled water was used as control. Roots of 25 human anterior teeth were sectioned longitudinally to obtain 50 dentin samples. Roughness values were evaluated by atomic force microscopy analysis on 5 groups (n=10) after each group was treated in one of the tested irrigant solutions for 10 min. Values were statistically analyzed by One-way analysis of variance, followed by a post hoc Tukey's test for pair-wise comparison. Dentin roughness significantly increased from 95.82 nm (control) to 136.02 nm, 187.07 nm, 142.29 nm and 150.92 nm with NaOCl, CHX, ImSNP and EDTA, respectively. CHX demonstrated a significantly higher roughness value compared to the other tested irrigants while no significant differences were seen in NaOCl, ImSNP and EDTA groups (P>0.242). ImSNP affected the physicochemical properties of dentin and raised its surface roughness; thus, this irrigant could impact bacterial and restorative material adhesion to root canal dentin walls.

  4. Dentin Morphology of Root Canal Surface: A Quantitative Evaluation Based on a Scanning Electronic Microscopy Study

    PubMed Central

    Lo Giudice, Giuseppe; Cutroneo, Giuseppina; Centofanti, Antonio; Artemisia, Alessandro; Bramanti, Ennio; Militi, Angela; Rizzo, Giuseppina; Favaloro, Angelo; Irrera, Alessia; Lo Giudice, Roberto; Cicciù, Marco

    2015-01-01

    Dentin is a vital, hydrated composite tissue with structural components and properties that vary in the different topographic portions of the teeth. These variations have a significant implication for biomechanical teeth properties and for the adhesive systems utilized in conservative dentistry. The aim of this study is to analyse the root canal dentin going from coronal to apical zone to find the ratio between the intertubular dentin area and the surface occupied by dentin tubules varies. Observations were conducted on 30 healthy premolar teeth extracted for orthodontic reasons in patients aged between 10 and 14. A SEM analysis of the data obtained in different canal portions showed that, in the coronal zone, dentinal tubules had a greater diameter (4.32 μm) than the middle zone (3.74 μm) and the apical zone (1.73 μm). The average number of dentinal tubules (in an area of 1 mm2) was similar in coronal zone (46,798 ± 10,644) and apical zone (45,192 ± 10,888), while in the middle zone they were lower in number (30,940 ± 7,651). However, intertubular dentin area was bigger going from apical to coronal portion. The differences between the analysed areas must be considered for the choice of the adhesive system. PMID:26413504

  5. Effects of oxidative irrigants on root dentin structure: Attenuated Total Reflection Fourier Transform Infrared Spectroscopy study.

    PubMed

    Atabek, Didem; Bodur, Haluk; Yalçin, Gözde; Kalayci, Şükrü

    2014-09-01

    The aim of this study was to compare the effect of oxidative irrigants on the organic and inorganic structure of root canal dentin. Fifty human 2nd premolar roots were used in the study. The dentin specimens prepared from those teeth were immersed in liquid nitrogen for 15 min. The frozen composition was titrated in a mixer and the obtained dentin powder was kept frozen at -70°C until use. Ten groups of 50mg dentin powder were immersed in agents (A: Ozone for 100 or 200 sec, B: 5.25% NaOCl, C: 2.25% NaOCl, D: 2% Chlorhexidine, E: 0.9% NaCl (control)) for 5 or 10 min. An Attenuated Total Reflection Fourier Transform Infrared Spectrophotometer (ATR FT-IR) was used to analyze dentin powder. The data were statistically analyzed by using Kruskall-Wallis analysis of variance. In all groups, collagen degradation was significantly increased compared to the control and 2% CHX groups (p<0.05). The use of ozone increased collagen degradation significantly compared to the use of 2.25% NaOCl and 2% Chlorhexidine for 5 min (p < 0.05). No significant differences were observed between ozone and 5.25% NaOCl-treated groups (p > 0.05). The structural composition of human dentin was significantly affected by the use of oxidative irrigants at higher concentrations.

  6. Ionizing irradiation affects the microtensile resin dentin bond strength under simulated clinical conditions.

    PubMed

    Yadav, Suman; Yadav, Harish

    2013-03-01

    This study evaluated the effect of ionizing radiations on resin-dentin interface in terms of marginal adaptation and micro-tensile bond strength under thermocycling and mechanical loading. Forty extracted human mandibular third molars were divided into four groups. GR I: No Irradiation and Class II MO cavities were prepared that were restored with composite restorations; GR II: Teeth were irradiated and restored; GR III: Teeth were restored and irradiated; GR IV: Teeth were restored during irradiation dosage fractions. All samples were thermal and mechanical loaded with 5000 cycles, 5 ± 2-55 ± 2°C, dwell time 30 s and 150,000 cycles at 60N. Resin-dentin slabs were trimmed into dumbbell-shaped slabs and microtensile bond strength was measured. The bond strength data was analyzed by one-way analysis of variance test. Irradiation before tooth preparation deteriorated the microtensile bond strength.

  7. Vitality of Enterococcus faecalis inside dentinal tubules after five root canal disinfection methods

    PubMed Central

    Vatkar, Niranjan Ashok; Hegde, Vivek; Sathe, Sucheta

    2016-01-01

    Aim: To compare the vitality of Enterococcus faecalis within dentinal tubules after subjected to five root canal disinfection methods. Materials and Methods: Dentin blocks (n = 60) were colonized with E. faecalis. After 4 weeks of incubation, the dentin blocks were divided into one control and five test groups (n = 10 each). The root canals of test groups were subjected to one of the disinfection methods, namely, normal saline (NS), sodium hypochlorite (NaOCl), chlorhexidine digluconate (CHX), neodymium-doped yttrium aluminum garnet (Nd: YAG) laser, and diode laser. The effect of disinfection methods was assessed by LIVE/DEAD BacLight stain under the confocal laser scanning microscopy to determine the “zone of dead bacteria” (ZDB). Mean values were calculated for ZDB and the difference between groups was established. Results: Penetration of E. faecalis was seen to a depth of >1000 μm. Viable bacteria were detected with NS irrigation. NaOCl and CHX showed partial ZDB. When the root canals were disinfected with Nd: YAG and diode lasers, no viable bacteria were found. Conclusion: E. faecalis has the ability to colonize inside dentinal tubules to a depth of >1000 μm. In contrast to conventional irrigants, both Nd: YAG and diode lasers were effective in eliminating the vitality of E. faecalis. NS, NaOCl, and CHX showed viable bacteria remaining in dentinal tubules. PMID:27656064

  8. Evaluation of Effects on the Adhesion of Various Root Canal Sealers after Er:YAG Laser and Irrigants Are Used on the Dentin Surface.

    PubMed

    Ozkocak, Ismail; Sonat, Bade

    2015-08-01

    The aim of this study was to evaluate the bond strength of various root canal sealers after various irrigation solutions and Er:YAG laser irradiation were used on root canal dentin. One hundred fifty freshly extracted human maxillary single-rooted teeth were used in this study. Teeth were sectioned transversally 4 mm below the cementoenamel junction. The root canal of each specimen was prepared using a tapered bur. Teeth were divided into 3 main groups by sealer (AH Plus Jet [Dentsply DeTrey, Konstanz, Germany], EndoSequence BC Sealer [Brasseler, Savannah, GA], and Real Seal [SybronEndo, Orange, CA]) and then divided into 5 subgroups by dentin treatment (distilled water, calcium hydroxide, sodium hypochlorite, EDTA, and Er:YAG laser). The specimens were placed immediately at 37°C and 100% humidity for 1 week. Then, the push-out test was applied. The maximum failure load was recorded in newtons and was used to calculate the push-out bond strength in MPa. Then, 3 random specimens from each group were examined under scanning electron microscopy. The resin root canal sealers had higher push-out bond strength than the bioceramic sealer, and the differences were statistically significant (P < .05) except in the sodium hypochlorite groups. The EDTA and Er:YAG laser applications removed the smear layer and increased the bond strength. The highest adhesion was observed in EDTA groups when each sealer was evaluated in itself. The bonding strength of root canal sealers is influenced by their properties and various dentin surface treatments. The scanning electron microscopic study showed that although the dentinal tubules were open, at the profile examination the sealers did not penetrate into the dentin canals in all specimens. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  9. Adhesion of Epiphany and AH Plus sealers to human root dentin treated with different solutions.

    PubMed

    Nunes, Vinicius Humberto; Silva, Ricardo Gariba; Alfredo, Edson; Sousa-Neto, Manoel D; Silva-Sousa, Yara T C

    2008-01-01

    This study evaluated comparatively the adhesion of Epiphany and AH Plus endodontic sealers to human root dentin treated with 1% NaOCl and 1% NaOCl+17% EDTA, using the push-out test. Sixty root cylinders obtained from maxillary canines had the canals prepared and were randomly assigned to 3 groups (n=20), according to root dentin treatment: GI - distilled water (control), GII - 1% NaOCl and GIII - 1% NaOCl+17% EDTA. Each group was divided into 2 subgroups (n=10) filled with either Epiphany or AH Plus. Bond strength push-out test data (kN) were obtained and analyzed statistically by ANOVA and Tukey's post-hoc test. There was statistically significant difference between sealers (AH Plus: 0.78 +/- 0.13; Epiphany: 0.61 +/- 0.19; p<0.01) and among root dentin treatments (distilled water: 0.58 +/- 0.19; 1% NaOCl: 0.71 +/- 0.12; 1% NaOCl+17% EDTA: 0.80 +/- 0.17; p<0.05). In conclusion, AH Plus sealer presented greater adhesion to dentin than Epiphany, regardless of the treatment of root canal walls.

  10. Decalcifying capability of irrigating solutions on root canal dentin mineral content

    PubMed Central

    Poggio, Claudio; Dagna, Alberto; Vinci, Andrea; Beltrami, Riccardo; Cucca, Lucia; Giardino, Luciano

    2015-01-01

    Background: Chelating agents are believed to aid root canal irrigation and to be able to remove the inorganic smear layer. Aims: The purpose of the present study was to evaluate and to compare the decalcifying capability of different irrigating solutions (Tubuliclean, Largal Ultra, ethylenediaminetetraacetic acid 17%, Tetraclean, Tetraclean NA). Materials and Methods: Sixty maxillary central incisors were used. Root canals were instrumented and irrigated. From each root, four comparable slices of cervical dentin were obtained. At three successive 5-min interval immersion times, the concentration of calcium extracted from root canal dentin was assessed with an inductively coupled plasma-atomic emission spectrometer. Statistical Analysis Used: Data were analyzed by means of Kruskal Wallis and Mann–Whitney tests. Significance was predetermined at P < 0.05. Results and Conclusions: For all irrigating solutions, the maximum amount of Ca2+ extracted from root canal dentin samples was reached after 10 min contact time except for citric acid-based agents (Tetraclean and Tetraclean NA) which induced a higher and still increasing calcium release even after 10 min contact time. In order to obtain an efficient decalcifying action on dentin and to facilitate the biomechanical procedures, citric acid-based irrigants can be applied. PMID:26097355

  11. Biofilm Formation within the Interface of Bovine Root Dentin Treated with Conjugated Chitosan and Sealer Containing Chitosan Nanoparticles

    PubMed Central

    DaSilva, Luis; Finer, Yoav; Friedman, Shimon; Basrani, Bettina; Kishen, Anil

    2013-01-01

    Objective To assess biofilm formation within sealer-dentin interfaces of root segments filled with gutta-percha and sealer incorporated with chitosan (CS) nanoparticles, without and with canal surface treatment with different formulations of CS. Methods Standardized canals of 4 mm bovine root segments (n=35) were filled with gutta-percha and Pulp Canal Sealer incorporated with CS nanoparticles without surface treatment (group CS), or after surface treatment with phosphorylated CS (group PHCS), CS-conjugated Rose Bengal and photodynamic irradiation (group CSRB) and a combination of both PHCS and CSRB (group RBPH). The control group was filled with gutta-percha and unmodified sealer. After 7 d of setting, specimens were aged in buffered solution at 37° C for 1 or 4 wks. Monospecies biofilms of Enterococcus faecalis were grown on specimens for 7 d in a chemostat-based biofilm fermentor. Biofilm formation within the sealer-dentin interface was assessed with confocal laser scanning microscopy. Results In the 4-wk aged specimens only, the mean biofilm areas were significantly smaller than in the control for CS (p=0.008), PHCS (p=0.012) and RBPH (p=0.034). Percentage of biofilm-covered interface also was significantly lower than in the control for CS (p=0.024) and PHCS (p=0.003). CS, PHCS and RBPH did not differ significantly. Conclusions Incorporating CS nanoparticles into the zinc-oxide eugenol sealer inhibited biofilm formation within the sealer-dentin interface. This effect was maintained when canals were treated with phosphorylated CS, and it was moderated by canal treatment with chitosan-conjugated Rose Bengal and irradiation. PMID:23321239

  12. Periapical microsurgery: the effect of root dentinal defects on short- and long-term outcome.

    PubMed

    Tawil, Peter Z; Saraiya, Veeral M; Galicia, Johnah C; Duggan, Derek J

    2015-01-01

    The purpose of this prospective clinical study was to evaluate the clinical outcome of endodontic microsurgery on roots exhibiting the presence or absence of dentinal defects at 1-year and 3-year follow-up period. One hundred fifty-five teeth were treated with periapical microsurgery using a modern microsurgical protocol in a private practice setting. The root apices were resected and inspected for dentinal defects with a surgical operating microscope and a 0.8-mm head diameter light-emitting diode microscope diagnostic probe light. After inspection, root-end preparations were performed using ultrasonic tips, and root-end fillings were placed. Follow-up visits occurred at 1 year and 3 years postoperatively. The primary outcome measure used was the change in the radiographic apical bone density, and the secondary outcome measure used was the absence of clinical symptoms. Of the 155 treated teeth, a total of 134 teeth were assessed at the 1-year follow-up and 127 teeth at the 3-year evaluation. In the "intact" group, 94.8% healed at 1 year, and 97.3% healed at 3 years. In the "dentinal defect" group, 29.8% healed at 1 year, and 31.5% healed at 3 years. The baseline root condition of either "dentinal defect" or "intact" showed a statistical difference in the healing outcome at both 1 and 3 years. This prospective periapical microsurgery study showed a significant superior clinical outcome for intact roots when compared with roots with dentinal defects at both 1 year and at 3 years postoperatively. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  13. Micro-CT assessment of dentinal micro-cracks after root canal filling procedures.

    PubMed

    De-Deus, G; Belladonna, F G; Silva, E J N L; Souza, E M; Carvalhal, J C A; Perez, R; Lopes, R T; Versiani, M A

    2017-09-01

    To evaluate the frequency of dentinal micro-cracks after root canal filling procedures with GuttaCore (GC), cold lateral compaction (CLC) and warm vertical compaction (WVC) techniques in mandibular molars using micro-computed tomographic analysis. Thirty mesial roots of mandibular molars, with a type II Vertucci's canal configuration, were prepared to working length with a Reciproc R40 instrument and randomly assigned to one of the three experimental groups (n = 10), according to the technique used for root filling: GC, CLC or WVC. The GC group was filled with a size 40 GC obturator, whilst CLC and WVC groups used conventional gutta-percha cones. AH Plus sealer was used in all groups. The specimens were scanned at an isotropic resolution of 14.25 μm before and after root canal preparation and after root filling. Then, all pre- and postoperative cross-sectional images of the roots (n = 41 660) were screened to identify the presence of dentinal defects. Overall, 30.75% (n = 12 810) of the pre- + post-filling images displayed dentinal defects. In the GC, CLC and WVC groups, dentinal micro-cracks were observed in 18.68% (n = 2510), 15.99% (n = 2389) and 11.34% (n = 1506) of the cross-sectional images, respectively. All micro-cracks identified in the post-filling scans were also observed in the corresponding post-preparation images. Root fillings in all techniques did not induce the development of new dentinal micro-cracks. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  14. Antibacterial substantivity of Carvacrol and sodium hypochlorite in infected bovine root dentin

    PubMed Central

    Sharifian, Mohammad Reza; Shokouhinejad, Noushin; Aligholi, Marzieh; Emaneini, Mohammad; Alizadeh, Javad

    2009-01-01

    INTRODUCTION: Various methods commonly used for cleaning and shaping root canals have not been successful in completely eradicating bacteria due to anatomic complexity and root canals irregularities. Disinfecting the canals with intracanal irrigants in addition to proper cleaning and shaping can produce a successful outcome. Antimicrobials with sustained antibacterial activity would be desirable for irrigation. The purpose of this study was to compare the antimicrobial substantivity of Carvacrol and 5.25% NaOCl in infected bovine root dentin. MATERIALS AND METHODS: One hundred and twenty dentin tubes prepared from bovine incisors were infected in vitro for 14 days with Enterococcus (E) faecalis. The specimens were divided into four groups including 1) Carvacrol, 2) NaOCl, 3) infected dentin tubes (positive control); and 4) sterile dentin tubes (negative control). Dentin chips were collected at five intervals (days 0, 1, 3, 7 and 28) using round burs with sequentially increasing diameters (which includes five layers of dentin) into Brain Heart Infusion (BHI) broth. In order to compare the pre- and post-irrigation antimicrobial activity of the irrigants the colony-forming units (CFU) were counted and classified as ‘CFU-before’ and ‘CFU-after’. After culturing, the number of CFU with the various experimental time and dentinal layers was recounted. Two-way ANOVA test was used to analyze the effects of time and materials. One-way ANOVA and supplemental Tukey HSD test were used for pair comparison. RESULTS: CFU was significantly reduced in NaOCl group when compared to all other experimental groups (P<0.05). CONCLUSION: The substantivity of NaOCl was significantly greater than Carvacrol. Further studies are required to investigate and approve Carvacrol as a final irrigant. PMID:23940484

  15. OH⁻ deficiency in dental enamel, crown and root dentine as studied by ¹H CRAMPS.

    PubMed

    Vyalikh, Anastasia; Mai, Ronald; Scheler, Ulrich

    2013-01-01

    High-resolution solid-state NMR based on combined rotation and multipulse spectroscopy (CRAMPS) has been applied to study chemical structures of dental tissues. The samples of human enamel, crown dentine and root dentin studied in this work were used without chemical pre-treatment. The quantitative ¹H NMR spectra permit an assignment to different structures and a quantification of the content of hydroxyl groups. While there is 40% hydroxyl content in the enamel, there is significantly less in the dentin, 14% in the crown and 9% in the root. Thus this study provides the direct evidence of OH⁻ ion deficiency in all dental tissues supporting earlier findings that bone and dental mineral apatite is poorly hydroxylated.

  16. Influence of etching time on bond strength in dentin irradiated with erbium lasers.

    PubMed

    Ferreira, Leila Soares; Apel, Christian; Francci, Carlos; Simoes, Alyne; Eduardo, Carlos P; Gutknecht, Norbert

    2010-11-01

    The purpose of this in vitro study was to evaluate the effect of etching time on the tensile bond strength (TBS) of a conventional adhesive bonded to dentin previously irradiated with erbium:yttrium-aluminum-garnet (Er:YAG) and erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) lasers. Buccal and lingual surfaces of 45 third molars were flattened until the dentin was exposed and randomly assigned to three groups (n = 30) according to the dentin treatment: control (not irradiated), irradiated with Er:YAG (1 W; 250 mJ; 4 Hz; 80.6 J/cm(2)) laser or Er,Cr:YSGG (4 W; 200 mJ; 20 Hz; 71.4 J/cm(2)) laser, and into three subgroups (n = 10) according to acid etching time (15 s, 30 s or 60 s) for each experimental group. After acid etching, the adhesive was applied, followed by the construction of an inverted cone of composite resin. The samples were immersed in distilled water (37 degrees C for 24 h) and subjected to TBS test [50 kilogram-force (kgf), 0.5 mm/min]. Data were analyzed by analysis of variance (ANOVA) and Tukey statistical tests (P < or = 0.05). Control group samples presented significant higher TBS values than those of all lased groups. Both irradiated groups exhibited similar TBS values. Samples subjected to the different etching times in each experimental group presented similar TBS. Based on the conditions of this in vitro study we concluded that Er:YAG and Er,Cr:YSGG laser irradiation of the dentin weakens the bond strength of the adhesive. Moreover, increased etching time is not able to modify the bonding strength of the adhesive to irradiated dentin.

  17. Etidronate from Medicine to Endodontics: effects of different irrigation regimes on root dentin roughness

    PubMed Central

    TARTARI, Talita; DUARTE JUNIOR, Anivaldo Pereira; SILVA JÚNIOR, José Otávio Carrera; KLAUTAU, Eliza Burlamaqui; SILVA E SOUZA JUNIOR, Mario Honorato; SILVA E SOUZA, Patrícia de Almeida Rodrigues

    2013-01-01

    An increase in dentin roughness, associated with surface composition, contributes to bacterial adherence in recontaminations. Surface roughness is also important for micromechanical interlocking of dental materials to dentin, and understanding the characteristics of the surface is essential to obtain the adhesion of root canal sealers that have different physico-chemical characteristics. Objectives To evaluate the effects of sodium hypochlorite (NaOCl), ethylenediaminetetraacetic (EDTA), etidronic (HEBP), and citric acid (CA) associated with different irrigation regimens on root dentin roughness. Material and Methods Forty-five root halves of anterior teeth were used. The root parts were sectioned in thirds, embedded in acrylic resin and polished to a standard surface roughness. Initially, the samples of each third were randomly assigned into 3 groups and treated as follows: G1 - saline solution (control); G2 - 5% NaOCl+18% HEBP mixed in equal parts; and G3 - 2.5% NaOCl. After initial measuments, the G3 samples were distributed into subgroups G4, G5 and G6, which were subjected to 17% EDTA, 10% CA and 9% HEBP, respectively. Following the new measuments, these groups received a final flush with 2.5% NaOCl, producing G7, G8 and G9. The dentin surface roughness (Ra) was determined before and after treatments using a profilometer. The Wilcoxon test (α<0.05) was used to compare the values before and after treatments, and the Friedman test (α<0.05) to detect any differences among root thirds. Results (i) NaOCl did not affect the surface roughness; (ii) there was a significant increase in roughness after the use of chelating agents (P<0.01); and (iii) only the G3 group showed a difference in surface roughness between apical third and other thirds of the teeth (P<0.0043). Conclusion Only the irrigation regimens that used chelating agents altered the roughness of root dentin. PMID:24212986

  18. Etidronate from medicine to endodontics: effects of different irrigation regimes on root dentin roughness.

    PubMed

    Tartari, Talita; Duarte Junior, Anivaldo Pereira; Silva Júnior, José Otávio Carrera; Klautau, Eliza Burlamaqui; Silva E Souza Junior, Mario Honorato; Silva E Souza Junior, Patrícia de Almeida Rodrigues

    2013-01-01

    An increase in dentin roughness, associated with surface composition, contributes to bacterial adherence in recontaminations. Surface roughness is also important for micromechanical interlocking of dental materials to dentin, and understanding the characteristics of the surface is essential to obtain the adhesion of root canal sealers that have different physico-chemical characteristics. To evaluate the effects of sodium hypochlorite (NaOCl), ethylenediaminetetraacetic (EDTA), etidronic (HEBP), and citric acid (CA) associated with different irrigation regimens on root dentin roughness. Forty-five root halves of anterior teeth were used. The root parts were sectioned in thirds, embedded in acrylic resin and polished to a standard surface roughness. Initially, the samples of each third were randomly assigned into 3 groups and treated as follows: G1 - saline solution (control); G2 - 5% NaOCl+18% HEBP mixed in equal parts; and G3 - 2.5% NaOCl. After initial measuments, the G3 samples were distributed into subgroups G4, G5 and G6, which were subjected to 17% EDTA, 10% CA and 9% HEBP, respectively. Following the new measuments, these groups received a final flush with 2.5% NaOCl, producing G7, G8 and G9. The dentin surface roughness (Ra) was determined before and after treatments using a profilometer. The Wilcoxon test (α<0.05) was used to compare the values before and after treatments, and the Friedman test (α<0.05) to detect any differences among root thirds. (i) NaOCl did not affect the surface roughness; (ii) there was a significant increase in roughness after the use of chelating agents (P<0.01); and (iii) only the G3 group showed a difference in surface roughness between apical third and other thirds of the teeth (P<0.0043). Only the irrigation regimens that used chelating agents altered the roughness of root dentin.

  19. Effect of Peracetic Acid as A Final Rinse on Push Out Bond Strength of Root Canal Sealers to Root Dentin

    PubMed Central

    Gaddala, Naresh; Veeramachineni, Chandrasekhar

    2015-01-01

    Background Smear layer which was formed during the instrumentation of root canals hinders the penetration of root canal sealers to root dentin and affect the bond strength of root canal sealers to root dentin. Final irrigant such as demineralizing agents are used to remove the inorganic portion of the smear layer. In the present study, peracetic acid used as a final rinse, to effect the bond strength of root canal sealers to root dentin. Aim The purpose of the present study was to evaluate the efficacy of peracetic acid as a final irrigant on bond strength of root canal sealers to root dentin. Materials and Methods Sixty six freshly extracted human single rooted mandibular premolars were used for this study. After decoronation the samples were instrumented with Protaper upto F3 and irrigated with 5.25% NaOcl. The teeth were then divided into three groups based on final irrigant used: Group-1(control group) Canals were irrigated with distilled water. Group-2: Canals were irrigated with peracetic acid. Group-3: Canals were irrigated with smear clear. Each group was further divided into three subgroups (n=30) based on the sealer used to obturate the canals. Subgroup-1: kerr, Subgroup-2: Apexit plus, Subgroup-3: AH PLUS. Each sealer was mixed and coated to master cone and placed in the canal. The bonding between sealer and dentin surface was evaluated using push out bond strength by universal testing machine. The mean bond strength values of each group were statistically evaluated using Two-way ANOVA followed by Tukey post-hoc test. Results Significant difference was found among the bond strength of the sealers. But, there is no statistically significant difference between the groups irrigated with peracetic acid and smear clear compared to control group. AH Plus showed highest bond strength irrespective of the final irrigant used. Conclusion Peracetic acid when employed as final irrigant improved the bond strength of root canal sealers compared to control group but

  20. Raman study of human dentin irradiated with Er:YAG laser

    NASA Astrophysics Data System (ADS)

    S. Soares, Luis E.; Martin, Airton A.; Brugnera, Aldo, Jr.; Zanin, Fatima A.; Arisawa, Emilia A.; T. Pacheco, Marcos T.

    2004-09-01

    Raman Spectroscopy was used to examine the distribution of the mineral and organic components in the human dentin before and after the chemical and thermal etching process. Polished dentin disks (n = 6/group) with 4mm thickness from twelve third molars were irradiated with Er:YAG laser. The dentin disks were prepared by polishing through a series of SiO2 papers with water and cleaned by ultrasonic system. Four pretreatment were performed. The disks were etched with 37% phosphoric acid (group I), Er:YAG laser 80mJ, 3Hz, 30s. (group II), Er:YAG laser 120mJ, 3Hz, 30s. (group III) and Er:YAG laser 180mJ, 3Hz, 30s. (group IV). The Raman spectra obtained from normal and treated dentin were analyzed. Attention was paid to the mineral PO4 (962 cm-1), CO3 (1073 cm-1) and to the organic component (1453cm-1). Raman spectroscopy showed that the mineral and organic dentin content were more affected in autoclaved teeth than in the specimens treated by Thymol. Peak area reduction in the specimens treated by Thymol in group I and II showed to be the most conservative procedures regarding to changes in organic and inorganic dentin components. Pulse energies of 120 and 180mJ showed to produce more reduction in the organic and inorganic content associated with more reduction in the peak areas at 960 and 1453cm-1.

  1. Er:YAG laser irradiation of human dentin: Raman study of collagen

    NASA Astrophysics Data System (ADS)

    Soares, Luis E. S.; Martin, Airton A.; Brugnera, Aldo, Jr.; Zanin, Fatima; Arisawa, Emilia A.; Pacheco, Marcos T. T.

    2004-05-01

    Raman Spectroscopy was used to examine the distribution of the organic components in the human dentin before and after the chemical and thermal etching process. Polished dentin disks (n = 6/group) with 4mm thickness from twelve third molars were irradiated with Er:YAG laser. The dentin disks were prepared by polishing through a series of SiO2 papers with water and cleaned by ultrasonic system. Four pretreatment were performed. The disks were etched with 37% phoshporic acid for 15 s (group 1), Er:YAG laser 80 mJ, 3Hz, 30s. (group II), Er:YAG laser 120 mJ, 3Hz, 30s. (group III) and Er:YAG laser 180mJ, 3Hz, 30s. (group IV). The Raman spectra obtained from normal and treated dentin were analyzed. Attention was paid to the organic component (1453cm-1). Raman spectroscopy showed that the organic dentin content were more affected in autoclaved teeth than in the specimens treated by Thymol. Peak area reduction in the specimens treated by Thymol in group I and II showed to be the most conservative procedures regarding to changes in organic dentin components. Pulse energies of 120 and 180 mJ showed to preduce more reduction in the organic content associated with more reduction in the peak areas at 1453 cm-1.

  2. Effects of the Er, Cr:YSGG laser irradiation on dentin bond strength

    NASA Astrophysics Data System (ADS)

    Piccioni, M. A. R. V.; Neves, T. P. C.; Kubo, C. S.; Saad, J. R. C.; Campos, E. A.

    2016-02-01

    The aim of this study is to evaluate the influence of Er,Cr:YSGG laser irradiation and bur on the bond strength of different single step self-etch adhesive systems in normal and artificially hypermineralized dentin. In total, 112 human molars were selected. The specimens were randomly divided into two different groups according to the type of dentin. The teeth from each group were randomly divided into two subgroups according to the adhesive system used: Clearfil S3 Bond and Optibond All in One. Each subgroup received different treatments: (1) conditioning conventional; (2) conditioning of the dentin surface with Er,Cr:YSGG  +  application of the adhesive system; (3) ‘surface roughening’ dentin with 3098 diamond bur  +  application of the adhesive system. The matrices were positioned, filled with composite resin and photoactivated for 40 s. After a storage period of 24 h in a humid environment, the specimens were submitted to microshear bond strength testing. Subsequently, the fracture pattern of each sample was determined. One specimen per group was prepared in order to evaluate the interface and/or appearance of resin tags. The data of the microshear bond strength (μSBS) were analyzed by two-way ANOVA and Tukey’s (p  <0.05). In the hypermineralized dentin, there was no significant statistical difference between all the treatments employed, enhancing the option of employing single step self-etch adhesives in dentin sclerotic.

  3. Two pre-treatments for bonding to non-carious cervical root dentin.

    PubMed

    Flury, Simon; Peutzfeldt, Anne; Lussi, Adrian

    2015-12-01

    To investigate the effect of airborne-particle abrasion or diamond bur preparation as pre-treatment steps of non-carious cervical root dentin regarding substance loss and bond strength. 45 dentin specimens-produced from crowns of extracted human incisors by grinding the labial surfaces with silicon carbide papers (control) were treated with one of three adhesive systems (Group 1A-C; A: OptiBond FL, B: Clearfil SE Bond, or C: Scotchbond Universal; n= 15/adhesive system). Another 135 dentin specimens (n = 15/group) produced from the labial, non-carious cervical root part of extracted human incisors were treated with one of the adhesive systems after either no pre-treatment (Group 2A-C), pre-treatment with airborne-particle abrasion (CoJet Prep and 50 µm aluminum oxide powder; Group 3A-C), or pre-treatment with diamond bur preparation (40 µm grit size; Group 4A-C). Substance loss caused by the pre-treatment was measured in Groups 3 and 4. After treatment with the adhesive systems, resin composite was applied and all specimens were stored (37°C, 100% humidity, 24 hours) until measurement of micro-shear bond strength (µSBS). Data were analyzed with a nonparametric ANOVA followed by Kruskal-Wallis and Wilcoxon rank sum tests (level of significance: α = 0.05). Overall substance loss was significantly lower in Group 3 (median: 19 µm) than in Group 4 (median: 113 µm; P < 0.0001). There were no significant differences in µSBS between the adhesive systems (A-C) in Group 1, Group 3, and Group 4 (P 0.133). In Group 2, OptiBond FL (Group 2A) and Clearfil SE Bond (Group 2B) yielded significantly higher µSBS than Scotchbond Universal (Group 2C; P ≤ 0.032). For OptiBond FL and Clearfil SE Bond, there were no significant differences in µSBS between the ground crown dentin and the non-carious cervical root dentin regardless of any pre-treatment of the latter (both P = 0.661). For Scotchbond Universal, the µSBS to non-carious cervical root dentin without pre-treatment was

  4. Effect of Argon Plasma on Root Dentin after Use of 6% NaOCl.

    PubMed

    Prado, Maíra do; Roizenblit, Rafael Nigri; Pacheco, Laura Villela; Barbosa, Carlos Augusto de Melo; Lima, Carolina Oliveira de; Simão, Renata Antoun

    2016-01-01

    The aim of this study was to evaluate the effect of argon plasma on dentin surface after use of 6% NaOCl. Sixty bovine incisors had their crowns removed, the roots split, and the segments planed. One hundred twenty segments of the cervical third were used. The samples were divided in two groups (n=60): immersed in 6% NaOCl, washed, dried and then immersed in 17% EDTA, washed and dried and Argon group: after treatment described for the CONTROL GROUP, non-thermal argon plasma was applied for 30 s. Ten samples were evaluated by scanning electron microscopy in each group. Other ten samples were analyzed by Fourier transform infrared spectroscopy (FTIR). Thirty samples were analyzed with a goniometer to measure the contact angle between the dentin surfaces and solutions, to determine the surface free energy. The last ten samples were used to evaluate the wettability of AH Plus sealer. Data were statistically analyzed using Kruskal Wallis and Mann-Whitney tests (p<0.05). The results of this study showed that argon plasma did not modify the surface topography. FTIR analysis showed chemical modifications after plasma treatment. Argon plasma increased the surface free energy of dentin and AH Plus wettability. In conclusion, argon plasma treatment modified chemically the dentin surface. This treatment increased the surface free energy and wettability of an epoxy resin root canal sealer, favoring its bonding to dentin surfaces.

  5. Effect of various laser irradiations on the mineral content of dentin

    PubMed Central

    Dilber, Erhan; Malkoc, Meral Arslan; Ozturk, A. Nilgun; Ozturk, Firat

    2013-01-01

    Objective: The aim of this study was to evaluate the mineral content of dentin irradiation with Erbium: yttrium-aliminum-garnet (Er:YAG), Neodmiyum:yttrium-aliminum garnet (Nd:YAG) and potassium titanium phosphate (KTP) laser used for in the treatment of dentin hypersensitivity. Methods: Six extracted wisdom, unerupted molar teeth were used in this study. The enamel of the teeth was removed with a conventional bur under water cooling to expose the dentin surface. The teeth were mounted in a slow-speed, diamond-saw, sectioning machine. Two dentin slabs were obtained from each tooth and each slab was sectioned so that 4 slabs were made from each teeth. Then dentin slabs were randomly divided into four groups. Group A: Control Group, Group B: Er:YAG laser, Group C: Nd:YAG laser, Group D: KTP laser. The levels of Ca, K, Mg, Na,P and Ca/P mineral ratio in each dentin slab were measured by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Data were analysed by one way analysis of variance (ANOVA) and Tukey HSD tests. One sample from each group was prepared for scanning electron microscopy (SEM). Results: There were no significant differences between the groups for Ca, K, Mg, Na,P and Ca/P mineral ratio (P>.05). SEM photographs indicated that there were melted areas around the exposed dentin tubules in groups treated with Er:YAG and KTP lasers. Conclusion: This study demonstrated that laser etching with the Er:YAG, Nd:YAG, KTP laser systems did not affect the compositional structure of the dentin surfaces. PMID:23407579

  6. Effect of various laser irradiations on the mineral content of dentin.

    PubMed

    Dilber, Erhan; Malkoc, Meral Arslan; Ozturk, A Nilgun; Ozturk, Firat

    2013-01-01

    THE AIM OF THIS STUDY WAS TO EVALUATE THE MINERAL CONTENT OF DENTIN IRRADIATION WITH ERBIUM: yttrium-aliminum-garnet (Er:YAG), Neodmiyum:yttrium-aliminum garnet (Nd:YAG) and potassium titanium phosphate (KTP) laser used for in the treatment of dentin hypersensitivity. Six extracted wisdom, unerupted molar teeth were used in this study. The enamel of the teeth was removed with a conventional bur under water cooling to expose the dentin surface. The teeth were mounted in a slow-speed, diamond-saw, sectioning machine. Two dentin slabs were obtained from each tooth and each slab was sectioned so that 4 slabs were made from each teeth. Then dentin slabs were randomly divided into four groups. Group A: Control Group, Group B: Er:YAG laser, Group C: Nd:YAG laser, Group D: KTP laser. The levels of Ca, K, Mg, Na,P and Ca/P mineral ratio in each dentin slab were measured by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Data were analysed by one way analysis of variance (ANOVA) and Tukey HSD tests. One sample from each group was prepared for scanning electron microscopy (SEM). There were no significant differences between the groups for Ca, K, Mg, Na,P and Ca/P mineral ratio (P>.05). SEM photographs indicated that there were melted areas around the exposed dentin tubules in groups treated with Er:YAG and KTP lasers. This study demonstrated that laser etching with the Er:YAG, Nd:YAG, KTP laser systems did not affect the compositional structure of the dentin surfaces.

  7. Dentine removal in the coronal portion of root canals following two preparation techniques.

    PubMed

    Plotino, G; Grande, N M; Falanga, A; Di Giuseppe, I L; Lamorgese, V; Somma, F

    2007-11-01

    To measure the root canal area and the reduction of the mesial and buccal/lingual wall thickness at the level of the coronal interference in mesial roots of mandibular molars after instrumentation with a crown-down or a simultaneous root canal preparation technique. Twenty mesial roots of first mandibular molars with a moderate root canal curvature were embedded in resin and sectioned horizontally at the level of the coronal interference, using a modification of the Bramante technique. After scanning and processing, the sections were reassembled. One root canal of each root was prepared using ProTaper instruments, while Mtwo instruments were used in the other root canal of the same mesial root. After scanning and processing, the data obtained were analysed for two parameters: changes in root canal area after instrumentation (Delta A) and reduction of the mesial and buccal/lingual wall thickness (Delta T). The data were subjected to Student's t-tests for statistical analysis at a significance level of P < 0.05. No statistically significant differences were found between the two groups with respect to the changes in the areas (Delta A) at the level considered (P = 0.410). No statistically significant differences were noticed between the two groups for dentine thickness (Delta T) of both the mesial wall (P = 0.077) and the buccal or lingual wall (P = 0.171). There was no difference between the ProTaper and Mtwo groups for the amount of dentine removed.

  8. 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

  9. Periapical Microsurgery: The effect of root dentinal defects on short and long term outcome

    PubMed Central

    Tawil, Peter Z.; Saraiya, Veeral M.; Galicia, Johnah C.; Duggan, Derek J.

    2015-01-01

    Introduction The purpose of this prospective clinical study is to evaluate the clinical outcome of endodontic microsurgery on roots exhibiting the presence or absence of dentinal defects at one year and three-year follow up period. Methods 155 teeth were treated with periapical microsurgery using a modern microsurgical protocol in a private practice setting. The root apices were resected and inspected for dentinal defects with a Surgical Operating Microscope and a 0.8mm head diameter LED microscope diagnostic probe light. After inspection, retrograde preparations were performed using ultrasonic tips and retrograde fillings were placed. Follow up visits occurred at one year and three years post-operatively. The primary outcome measure employed was the change in the radiographic apical bone density and the secondary outcome measure used was the absence of clinical symptoms. Results Out of the 155 treated teeth, a total of 134 teeth were assessed at the one-year follow-up and 127 teeth at the three-year evaluation. The “Intact” group had 94.8% healed at one year and 97.3% healed at three years. The “Dentinal Defect” group had 29.8% healed at one year and 31.5% healed at three years. The baseline root condition of either “Dentinal Defect” or “Intact” showed a statistical difference in the healing outcome at both one year and at three years. Conclusions This prospective periapical microsurgery study showed a significant superior clinical outcome for intact roots when compared to roots with dentinal defects at both 1 year and at 3 years post-operatively. PMID:25282374

  10. Effect of pretreatment on Er:YAG laser-irradiated dentin.

    PubMed

    Chen, Min-le; Ding, Jiang-feng; He, Yong-jiang; Chen, Yi; Jiang, Qian-zhou

    2015-02-01

    Erbium:yttrium-aluminum-garnet (Er:YAG) laser preparation of tooth cavities for restoration is an increasingly popular method, but its compatibility with existing composite material bonding protocols has not been fully defined. This study evaluated the effect of laser and etchant pretreatments on the performance of one-bottle self-etch adhesives in Er:YAG laser-prepared dentin. Eight groups of 20 extracted teeth were established to investigate bonding in tested dentin disks. Various combinations of laser preparation (with/without), pretreatment (none/acid-etch/low-fluence Er:YAG irradiation), and self-etching adhesive (G-Bond Plus or Xeno V) were tested. Samples were then restored with composite resin and subjected to a tensile bond strength (TBS) test. We also performed scanning electron microscopy (SEM) on dentin disks from some of these groups before and after adhesive application to evaluate their microscopic morphological appearance. Statistical analysis (Dunnett T3 test coupled with the general linear model at 5% significance level) revealed that the laser preparation of dentin did not impact on TBS (p = 0.914), whereas pretreatment with either phosphoric acid (p < 0.0001) or low-fluence Er:YAG laser irradiation (p < 0.0001) significantly increased TBS, although there was no difference between them in their respective elevation of TBS. SEM analysis demonstrated that both acid and laser pretreatments reduced irregularities and produced a more homogeneous surface. Er:YAG laser preparation does not compromise the efficacy of one-step self-etch dentin adhesives, and pretreatment with phosphoric acid or low-fluence Er:YAG laser can significantly increase the TBS of adhesion to this irradiated dentin.

  11. Diode laser radiation and its bactericidal effect in root canal wall dentin.

    PubMed

    Gutknecht, N; van Gogswaardt, D; Conrads, G; Apel, C; Schubert, C; Lampert, F

    2000-04-01

    The aim of this study was to investigate the antibacterial effect of a diode laser in deep root canal dentin. The microbial colonization of root canal dentin can lead to failures in conventional endodontic treatment if an inadequate bacterial reduction only is achieved through canal treatment and chemical disinfection. 100 microm, 300 microm and 500 microm bovine dentin slices obtained by longitudinal sections were sterilized and inoculated on one side with an Enterococcus faecalis suspension. Laser radiation was performed on the opposite side with the diode laser (810 nm) at a setting of 3 W in continuous mode (CW). Radiation was performed using a 400-microm tapered fiber tip at an angle of approximately 5 degrees to the surface over a period of 30 seconds. The output power at the distal end of the tip was 0.6 W. The bacteria were then eluted through vibration and cultured on blood agar plates. The colony count reflected the antibacterial effect of laser radiation as a function of the layer thickness. A mean bacterial reduction of 74% was achieved even with a 500-microm thick slice. This investigation indicates that the diode laser radiation reduces the number of bacteria in deep layers of infected root canal wall dentin.

  12. A morphological in vitro study of the effects of Nd:YAG laser on irradiated cervical dentin.

    PubMed

    de Magalhães, Manoelita Figueiredo; Matson, Edmir; de Rossi, Wagner; Alves, José Bento

    2004-12-01

    The purpose of this in vitro study was to verify the efficacy of Nd:YAG pulsed laser at 1064 nm in sealing dentinal tubules in vitro, with its resulting morphological changes using clinical parameters applicable to the treatment of dentin hypersensitivity. Although many papers have been written on the subject, no rapid, efficient, and long-lasting treatment for this problem has been developed. Twenty healthy extracted human teeth were kept in saline solution. Cervical cement was removed with a no. 57FG bur to expose approximately 4 mm(2) of dentin. Two groups were in the buccal aspect (A and B-irradiated) and one group in the lingual aspect (C-control not irradiated) of the same tooth. Samples with a remaining dentinal thickness between 1 and 1.5 mm were selected. Irradiation parameters were 30 mJ, 0.3W(Group A) and 40 mJ, 0.4 W(Group B); 7 Hz was used in both groups in two 43-sec applications each, with a 10-sec interval. In 10 samples, the dentinal surface underwent SEM examination for study. The other 10 remaining irradiated samples were centrally cleaved to study laser penetration depth in dentin (SEM). Obliteration of dentinal tubule openings and solidification of the dentin surface were observed in all irradiated samples. Laser penetration depth in dentin (SEM) varied from 1 to 7 microm, depending on irradiation parameters used in each group. We concluded that the use of the Nd:YAG laser was a very effective measure for obliterating dentinal tubule openings.

  13. Effect of an acid diet allied to sonic toothbrushing on root dentin permeability: an in vitro study.

    PubMed

    Pinto, Shelon Cristina Souza; Batitucci, Roberta Grasseli; Pinheiro, Michele Carolina; Zandim, Daniela Leal; Spin-Neto, Rubens; Sampaio, José Eduardo Cezar

    2010-01-01

    This study quantified alterations in root dentin permeability after exposure to different acid beverages. Twenty-five third molars were sectioned below the cementoenamel junction, the root segment was collected, and the pulp tissue was removed. The root segments were connected to a hydraulic pressure apparatus to measure the permeability of root dentin after the following sequential steps, with 5 specimens in each: 1) phosphoric acid etching for 30 s (maximum permeability), 2) root planning to create new smear layer, 3) exposure to different acid substances for 5 min (orange, cola drink, vinegar, white wine, lemon juice), 4) toothbrushing with sonic toothbrush for 3 min, 5) toothbrushing with sonic toothbrush plus dentifrice for 3 min. Considering step I as 100%, the data were converted into percentage and each specimen was its own control. Data were analyzed statistically by Kruskal-Wallis and Dunn's post test at 5% significance level. All acidic substances increased dentin permeability significantly after scraping (p< 0.05). Toothbrushing after exposure to acid substances decreased dentin permeability and the association with dentifrice accentuated the decrease (p< 0.05), except for the specimens treated with cola drink. Thus, it may be concluded that all tested acid fruit juices increased dentin permeability, and toothbrushing with or without dentifrice can decrease root dentin permeability after dentin exposure to acid diet.

  14. Effect of gutta-percha solvents on fiberglass post bond strength to root canal dentin.

    PubMed

    Guedes, Orlando A; Chaves, Gustavo S; Alencar, Ana H G; Borges, Alvaro H; Estrela, Cyntia R A; Soares, Carlos J; Estrela, Carlos

    2014-06-01

    The purpose of this study was to investigate the influence of gutta-percha solvents on the bond strength of fiberglass post to root canal dentin. Forty bovine incisors were decoronated, prepared, filled, and randomly distributed into four groups (n = 10) according to the gutta-percha solvent used: control, xylene, eucalyptol and orange oil. After root canal treatment, the posts were cemented into the prepared root canals using a resin-based cement. A micro push-out test was executed, and the patterns of failure were assessed with microscopy. The data were analyzed using two-way ANOVA followed by Tukey's test. The control group exhibited greater bond strength compared to the eucalyptol group in the cervical and middle thirds of the root (P < 0.05); however, it did not differ significantly from the xylene and orange oil groups (P > 0.05). No difference was observed in the values of the xylene, orange oil, and eucalyptol groups (P > 0.05). The cervical third had higher values than the apical third for all tested solvents (P < 0.05). Adhesive failure between resin cement and dentin was the most frequent type of failure. The use of xylene and orange oil as gutta-percha solvents did not influence the bond strength of fiberglass posts to root canal dentin.

  15. Effect of Cyclic Loading on Bond Strength of Fiber Posts to Root Canal Dentin

    PubMed Central

    Khamverdi, Zahra; Damavandi, Leila Yazdani; Kasraei, Shahin

    2014-01-01

    Objective: The aim of this study was to evaluate the effect of cyclic loading on the bond strength of quartz fiber posts to root canal dentin after different surface treatments of different regions of root canal dentin. Materials and Methods: Forty-eight single-rooted human teeth were selected. Post spaces were prepared and then the teeth were divided into four groups: G1: no treatment (control); G2: irrigation with a chemical solvent; G3: etching with 37% phosphoric acid; G4: treatment with ultrasonic file. The fiber posts were cemented using dual-cured resin cement. Half of the specimens were load-cycled (10000 cycles, 3 cycles/s) and the others did not undergo any load cycling. From each root, two slides measuring 1 mm in thickness were obtained from the apical and cervical regions. The push-out bond strength test was performed for each slice. Data were analyzed by using 3-way ANOVA and Tukey HSD tests. The fracture modes were evaluated under a stereomicroscope at ×20. Results: The effect of load cycling and surface treatment as the main factors and the interaction of main factors were not significant (P=0.734, P=0.180, and P=0.539, respectively). The most frequent failure mode under the stereomicroscope was adhesive. Conclusion: It appears that load cycling and surface treatment methods had no effect on the bond strength of fiber posts to root canal dentin, but it depended on the region of the root canal dentin. PMID:24910680

  16. Characterization of caries progression on dentin after irradiation with Nd:YAG laser by FTIR spectroscopy and fluorescence imaging

    NASA Astrophysics Data System (ADS)

    Ana, P. A.; Brito, A. M. M.; Zezell, D. M.; Lins, E. C. C. C.

    2015-06-01

    Considering the use of high intensity lasers for preventing dental caries, this blind in vitro study evaluated the compositional and fluorescence effects promoted by Nd:YAG laser (λ=1064 nm) when applied for prevention of progression of dentin caries, in association or not with topical application of acidulated phosphate fluoride (APF). Sixty bovine root dentin slabs were prepared and demineralized by 32h in order to create early caries lesions. After, the slabs were distributed into six experimental groups: G1- untreated and not submitted to a pH-cycling model; G2- untreated and submitted to a pH-cycling model; G3- acidulated phosphate fluoride application (APF); G4- Nd:YAG irradiation (84.9 J/cm2, 60 mJ/pulse); G5- treated with Nd:YAG+APF; G6- treated with APF+Nd:YAG. After treatments, the samples of groups G2 to G6 were submitted to a 4-day pH-cycling model in order to simulate the progression of early caries lesions. All samples were characterized by the micro-attenuated total reflection technique of Fourier transformed infrared spectroscopy (μATR-FTIR), using a diamond crystal, and by a fluorescence imaging system (FIS), in which it was used an illuminating system at λ= 405±30 nm. Demineralization promoted reduction in carbonate and phosphate contents, exposing the organic matter; as well, it was observed a significant reduction of fluorescence intensity. Nd:YAG laser promoted additional chemical changes, and increased the fluorescence intensity even with the development of caries lesions. It was concluded that the compositional changes promoted by Nd:YAG, when associated to APF, are responsible for the reduction of demineralization progression observed on root dentin.

  17. Effects of ArF excimer laser irradiation of dentin on the tensile bonding strength to composite resin.

    PubMed

    Sano, Kazunobu; Tonami, Ken-Ichi; Ichinose, Shizuko; Araki, Kouji

    2012-02-01

    The purpose of the study was to evaluate the effects of argon fluoride (ArF) excimer laser irradiation on the tensile bonding strength (TBS) of dentin to composite resin. Dental lasers use a photothermal process, which potentially entails risk of tissue damage caused by heat affecting the bond strength of resins. The ArF excimer laser functions by a photochemical process in which the energy of photons directly cuts covalent bonds in molecules without generating heat. Twenty extracted human molars were sectioned perpendicularly to the tooth axis to expose a flat dentin surface. The surfaces were treated with various combinations of ArF excimer laser irradiation, primer treatment, and bonding treatment. After composite resin was built up on the treated dentin surface, specimens with a 1×1 mm bonding interface were prepared and subjected to TBS tests. Treated dentin surfaces were also observed using transmission electron microscopy (TEM). Specimens that underwent laser irradiation followed by bonding treatment had a TBS that did not differ significantly from that of specimens that received conventional treatment, with or without priming. TEM observations showed sectioned and dispersed collagen matrix in the hybrid layer after laser irradiation, priming, and bonding, but no hybrid layer after laser irradiation and bonding at the treated dentin surface. The TBS of conditioning with ArF excimer laser irradiation was identical to that with conventional treatment when bonding was used. The bonding mechanism with the ArF irradiation differed from that of conventional bonding depending upon dentin hybridization.

  18. Crystallographic Texture and Elemental Composition Mapped in Bovine Root Dentin at the 200 nm Level

    PubMed Central

    Deymier-Black, A. C.; Veis, A.; Cai, Z.; Stock, S. R.

    2015-01-01

    Summary The relationship between the mineralization of peritubular dentin (PTD) and intertubular dentin (ITD) is not well understood. Tubules are quite small, diameter ~2 μm, and this makes the near-tubule region of dentin difficult to study. Here, advanced characterization techniques are applied in a novel way to examine what organic or nanostructural signatures may indicate the end of ITD or the beginning of PTD mineralization. X-ray fluorescence intensity (Ca, P, and Zn) and X-ray diffraction patterns from carbonated apatite (cAp) were mapped around dentintubules at resolutions ten times smaller than the feature size (200 nm pixels), representing a 36% increase in resolution over earlier work. In the near tubule volumes of near-pulp, root dentin, Zn intensity was higher than in ITD remote from the tubules. This increase in Zn2+, as determined by X-ray absorption near edge structure analysis, may indicate the presence of metalloenzymes or transcription factors important to ITD or PTD mineralization. The profiles of the cAp 00.2 X-ray diffraction rings were fitted with a pseudo-Voigt function, and the spatial and azimuthal distribution of these rings’ integrated intensities indicated that the cAp platelets were arranged with their c-axes aligned tangential to the edge of the tubule lumen. This texture was continuous throughout the dentin indicating a lack of structural difference between in the Zn rich near-tubular region and the remote ITD. PMID:23630059

  19. Morphological analysis of the retrofilled apical dentin surfaces irradiated with CO2 laser

    NASA Astrophysics Data System (ADS)

    Aun, Carlos E.; Lage-Marques, Jose L.; Gavini, Giulio; Clasen, Naya F.; Matsumoto, Koukichi

    1998-04-01

    Countless researches conducted in these last years have compared the sealing capacity of various materials for retrofillings. Besides, the association of laser irradiation to traditional procedures inquires to increase the success of this kind of treatment. The purpose of this study was to evaluate the morphological changes on dentin surface and the junction between retrofilling material and apical cavity, with different materials irradiated or not with CO2 laser, in scanning electron microscopy. The following materials were used: Group A yields Super EBA; group B yields Super EBA and CO2 laser irradiation (Luxar System); group C yields Glass Ionomer Cement; group D yields Glass Ionomer Cement and CO2 laser. In groups B and D the power set was 2 watts, 20 msec, with a CT3105 ceramic point, and the power density for the CO2 laser application was 397,93 w/cm2. The morphological analysis permitted to conclude that the dentin laser irradiation showed different and less intense superficial alteration when compared with retrofilling materials. In most cases, the alterations to the material surfaces showed cavities and craters. Group B presented more irregular and affected surfaces, creating blank spaces in the adjacent areas to the radicular dentinal surfaces after laser application, probably because of the carbonization.

  20. Moisture content of root canal dentine affects detection of microcracks using micro-computed tomography.

    PubMed

    Rödig, T; Müller, C; Hoch, M; Haupt, F; Schulz, X; Wiegand, A; Rizk, M

    2017-08-30

    To evaluate the effect of moisture content in root canal dentine on detection of microcracks using micro-computed tomography. Ten roots with and without craze lines or cracks (each n = 5) were selected and scanned six times with different moisture conditions of root dentine using a micro-CT scanner at a high resolution of 10.5 μm. Scanning conditions were as follows: (i) after 30-day wet storage, (ii) after 2-h dry time, (iii) after 48-h wet storage, (iv) after 24-h dry time, (v) after 48-h wet storage, (vi) after 2-h dry time. From each scan, cross-sectional images were obtained at intervals of 1 mm (total n = 708) and evaluated for the presence of dentinal microcracks twice by five calibrated blinded observers. Statistical analysis was performed by nonparametric analysis of variance for longitudinal data (P < 0.05). Intra-rater percentage agreement ranged between 92% and 98%, whereas inter-rater percentage agreement was 81% and 83%, respectively. No significant differences between all wet groups as well as between both groups with 2-h dry time were detected (P > 0.05). Almost no cracks were observed after wet storage with a significant increase of cracks after 2-h dry time (P < 0.001). Significantly more microcracks were identified after 24 h than after 2-h dry time (P < 0.004). Moisture content of dentine influenced detection of microcracks when evaluated using micro-CT. Scanning should be performed on dried specimens to allow reliable identification of dentinal defects. Formation of new cracks during dry periods up to 24 h was disproved. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  1. Comparative Analysis of Root Dentin Morphology and Structure of Human Versus Bovine Primary Teeth.

    PubMed

    Costa, Bruna M; Iwamoto, Alexsandra S; Puppin-Rontani, Regina M; Pascon, Fernanda M

    2015-06-01

    This study evaluated the structural and morphological differences between human and bovine primary root canals. Primary human maxillary central incisors (H) (n=9) and primary bovine incisors (B) (n=9) were selected. The roots were sectioned in the vestibular-lingual direction, planed and delimited in cervical, middle, and apical thirds. Tubule density (number of tubules per mm2) and diameter were analyzed by scanning electron microscopy (1,000 and 5,000×) using Image J 1.47 software. Data were submitted to two-way repeated measures ANOVA and Tukey tests (α=0.05). The highest tubule density was observed for B (28.527±1.717 mm2) compared with H (15.931±0.170 mm2) (p<0.01). Regarding root thirds, the cervical third presented a greater tubule density (26.417±11.654 mm2) than the apical third (17.999±5.873 mm2). The diameter of the dentin tubules was not different for cervical (3.50±0.08 µm), middle (3.45±0.30 µm) and apical thirds (3.42±0.33 µm) and substrate (H-3.29±0.14 µm; B-3.63±0.06 µm). It could be concluded that: (1) the radicular dentin structure of human and bovine primary teeth and root thirds differ in terms of the tubule density; (2) the radicular dentin morphology of human and bovine primary teeth and root thirds are similar in terms of the diameter of the dentin tubules.

  2. Identification of dentine sialoprotein in gingival crevicular fluid during physiological root resorption and orthodontic tooth movement.

    PubMed

    Kereshanan, Shalene; Stephenson, Pamela; Waddington, Rachel

    2008-06-01

    Root resorption is an unwanted effect of orthodontic tooth movement. Analysis of dentine proteins in gingival crevicular fluid (GCF) is a potentially safer method of quantifying root resorption compared with conventional radiographic methods. This study aimed to identify and quantify the dentine-specific matrix protein, dentine sialoprotein (DSP), released into GCF during physiological root resorption and orthodontic tooth movement. GCF was collected using micropipettes from 50 second primary molar sites undergoing physiological root resorption in 9- to 14-year olds [coronal group (Rc) with advanced resorption (n = 33) and apical group (Ra) with minimal resorption (n = 17)] and 20 subjects aged 8-14 years with erupted mandibular second premolars (control group). In addition, GCF was collected from 20 patients undergoing treatment with fixed appliances at two time points, immediately prior to orthodontic intervention (T0) and 12 weeks following commencement of fixed appliance therapy (T1). GCF samples were analysed for DSP using an immunoassay and levels semi-quantified using image analysis. To determine differences between the means of the various experimental and control groups, data based on the relative optical density volumes, were statistically analysed using a parametric t-test. DSP was raised in sites that were undergoing physiological resorption compared with the non-resorbing controls (P < 0.05). Notably, DSP was detected in some control samples. There was no difference in DSP levels for the Rc or Ra groups. DSP was also raised in GCF samples of teeth at 12 weeks following commencement of fixed appliance therapy (P < 0.001). The results highlight the potential for measuring DSP in GCF as a biomarker to monitor root resorption. Dentine is likely to be the major source for DSP in GCF, although alternative origins of bone and cementum are possible.

  3. Influence of adhesive cementation systems on the bond strength of relined fiber posts to root dentin.

    PubMed

    Rodrigues, Raquel Viana; Sampaio, Camila Sobral; Pacheco, Rafael Rocha; Pascon, Fernanda Miori; Puppin-Rontani, Regina Maria; Giannini, Marcelo

    2017-10-01

    Glass fiber post cementation procedures have undergone significant development. Relining the post with composite resin is a technique that aims to reduce resin cement thickness and consequently problems inherent to polymerization. Evidence is sparse regarding the efficacy of bonding procedures at increasing depths (from cervical to apical) using different adhesive cementation techniques. The purpose of this in vitro study was to evaluate the push-out bond strength (PBS) of composite resin relined glass fiber posts cemented to bovine root dentin using different adhesive cementation protocols. Eighteen bovine teeth (n=6) were embedded in polystyrene resin blocks, and the crowns were sectioned leaving a root portion of 20 mm in length. Root canals were prepared using rotary instruments provided by the post manufacturer (Whitepost DC #1), resulting in a uniform root canal preparation. The root canals were lubricated with a water-soluble glycerin gel. Silane (Prosil) was applied and the posts relined with a microhybrid composite resin (Filtek Z100) to conform to the root canal anatomy. Three adhesive cementation protocols were evaluated: a 3-step etch-and-rinse adhesive system (Adper Scotchbond Multi Purpose) in combination with a dual polymerizing resin cement (RelyX ARC); a universal adhesive system (Scotchbond Universal) associated with a dual polymerizing resin cement (RelyX Ultimate); and a self-adhesive dual polymerizing resin cement (RelyX Unicem 2). The roots were sectioned, resulting in four 2-mm segments at 4 different depths (cervical to apical) and evaluated by the PBS test, using a universal testing machine (Instron 4411) at 0.5 mm/min, until failure. Interfaces were evaluated by scanning electron microscopy, and failures were classified as cohesive failure in composite resin, cohesive failure in cement, cohesive failure in root dentin, adhesive failure, or mixed. Data were analyzed by 2-way split-plot ANOVA and the Tukey post hoc test (α=.05). No

  4. Chemical and morphological changes in human dentin after Er:YAGlaser irradiation: EDS and SEM analysis.

    PubMed

    Contreras-Arriaga, Belinda; Rodríguez-Vilchis, Laura Emma; Contreras-Bulnes, Rosalía; Olea-Mejìa, Oscar Fernando; Scougall-Vilchis, Rogelio José; Centeno-Pedraza, Claudia

    2015-11-01

    Sixty samples of human dentin were divided into six groups (n = 10) and were irradiated with Er:YAG laser at 100 mJ-19.9 J/cm(2), 150 mJ-29.8 J/cm(2), 100 mJ-35.3 J/cm(2), 150 mJ-53.0 J/cm(2), 200 mJ-70.7 J/cm(2), and 250 mJ-88.5 J/cm(2), respectively, at 7 Hz under a water spray. The atomic percentages of carbon, oxygen, magnesium, calcium, and phosphorus and the Ca-to-P molar ratio on the dentin were determined by energy dispersive X-ray spectroscopy. The morphological changes were observed using scanning electron microscopy. A paired t-test was used in statistical analysis before and after irradiation, and a one-way ANOVA was performed (P ≤ 0.05). The atomic percent of C tended to decrease in all of the groups after irradiation with statistically significant differences, O and Mg increased with significant differences in all of the groups, and the Ca-to-P molar ratio increased in groups IV, V, and VI, with statistically significant differences between groups II and VI. All the irradiated samples showed morphological changes. Major changes in the chemical composition of dentin were observed in trace elements. A significant increase in the Ca-to-P ratio was observed in the higher energy density groups. Morphological changes included loss of smear layer with exposed dentinal tubules. The changes produced by the different energy densities employed could have clinical implications, additional studies are required to clarify them. © 2015 Wiley Periodicals, Inc.

  5. 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.

  6. Effects of surface treatment and joint shape on microtensile bond strength of reattached root dentin segments.

    PubMed

    Liu, Jia; Kawada, Eiji; Oda, Yutaka

    2004-01-01

    An effective bonding technique for reattaching vertical root fracture segments has not yet been established. The purpose of this study was to investigate the effects of surface treatment and joint shape on bond strength of reattached root dentin segments. Microtensile dentin specimens (n=120, cross-sectional area=1.5 mm2) were obtained from 12 bovine teeth roots, and fractured under a tensile force. The segments of each group (n=6) were reattached by a 4-META/MMA-TBB adhesive resin after different treatments (etching or polishing, a 50-microm or 500-microm gap space, butt or wedge joint). The group with a 50-microm gap space and butt joint, which was not etched or polished, served as the control. After 24 hours of storage in 0.9% normal saline solution or thermal cycling (3000 cycles, 4 degrees C and 60 degrees C), the specimens were fractured in a universal testing machine at a crosshead speed of 1.0 mm/min. The microtensile bond strengths (MPa) were recorded. The bonded interface and fractured surface were observed by SEM (original magnification x 1000). The results were analyzed by a 2-way analysis of variance and the Fisher protected least significant difference post-hoc test (alpha=.05). Significantly higher bond strengths (P=.0001) were shown for the nonpolished group (9.78 +/- 4.44 MPa) and the etched group (9.31 +/- 1.23 MPa) than for the polished group (fractured before test). The wedge-shaped joint exhibited the highest bond strength (18.57 +/- 3.40 MPa, P=.0017). SEM observations showed that the penetration of resin tags along the oblique dentinal tubules was within the wedge joint. Etching and oblique tubule orientation contributed to significantly high bond strength of reattached segments to dentin after vertical root fracture.

  7. Root canal hydrophobization by dentinal silanization: improvement of silicon-based endodontic treatment tightness.

    PubMed

    Collart Dutilleul, Pierre-Yves; Fonseca, Cesar Gaitán; Zimányi, László; Romieu, Olivier; Pozos-Guillén, Amaury J; Semetey, Vincent; Cuisinier, Frédéric; Pérez, Elías; Levallois, Bernard

    2013-07-01

    A new strategy to improve silicon-based endodontic treatment tightness by dentine hydrophobization is presented in this work: root dentine was silanized to obtain a hydrophobic dentine-sealer interface that limits fluid penetration. This strategy was based on the grafting of aliphatic carbon chains on the dentine through a silanization with the silane end groups [octadecyltrichlorosilane (OTS) and octadecyltriethoxysilane]. Dentine surface was previously pretreated, applying ethylenediaminetetraacetic acid and sodium hypochlorite, to expose hydroxyl groups of collagen for the silane grafting. Collagen fibers exposure after pretreatment was visible with scanning electron microscopy, and Fourier transform infrared (FTIR) spectroscopy showed their correct exposition for the silanization (amide I and II, with 1630, 1580, and 1538 cm⁻¹ peaks corresponding to the vibration of C=O and C--N bonds). The grafting of aliphatic carbon chains was confirmed by FTIR (peaks at 2952 and 2923 cm⁻¹ corresponding to the stretching of C--H bonds) and by the increasing of the water contact angle. The most efficient hydrophobization was obtained with OTS in ethyl acetate, with a water contact angle turning from 51° to 109°. Gas and liquid permeability tests showed an increased seal tightness after silanization: the mean gas and water flows dropped from 2.02 × 10⁻⁸ to 1.62 × 10⁻⁸ mol s⁻¹ and from 10.8 × 10⁻³ to 5.4 × 10⁻³ µL min⁻¹, respectively. These results show clear evidences to turn hydrophilic dentine surface into a hydrophobic surface that may improve endodontic sealing.

  8. Antimicrobial efficacy of 3.8% silver diamine fluoride and its effect on root dentin.

    PubMed

    Hiraishi, Noriko; Yiu, Cynthia K Y; King, Nigel M; Tagami, Junji; Tay, Franklin R

    2010-06-01

    This study investigated the use of 3.8% silver diamine fluoride (Ag[NH3]2F) as an antibacterial agent against Enterococcus faecalis biofilms and its ability to penetrate dentinal tubules by the formation of silver salts. Biofilms were generated on membrane filter discs and subjected to 15-minute and 60-minute exposure times with 3.8% Ag(NH3)2F, saturated Ca(OH)2, 5.25% NaOCl (negative control), and 0.9% NaCl (positive control). Cleaned and shaped radicular dentin were applied with Ag(NH3)2F for 24, 48, and 72 hours. The presence of silver salts on the dentin surface was examined using low-pressure scanning electron microscopy. Both NaOCl and Ag(NH3)2F were effective against E. faecalis biofilms, with no significant difference in reduction of microorganisms for both exposure times. Silver deposits were present on 66.5% of the radicular dentin surfaces after 72-hour application of Ag(NH3)2F as simulated interappointment dressings. Penetration of the silver deposits was observed at most 40 microm into dentinal tubules after smear layer removal. Ag(NH3)2F has potential to be used as an antimicrobial root canal irrigant or interappointment dressing, especially in locations in which potential browning/blackening of dentin by metallic silver is not a major concern. Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  9. Does laser diode irradiation improve the degree of conversion of simplified dentin bonding systems?

    PubMed Central

    BRIANEZZI, Leticia Ferreira de Freitas; MAENOSONO, Rafael Massunari; BIM, Odair; ZABEU, Giovanna Speranza; PALMA-DIBB, Regina Guenka; ISHIKIRIAMA, Sérgio Kiyoshi

    2017-01-01

    Abstract Simplified dentin-bonding systems are clinically employed for most adhesive procedures, and they are prone to hydrolytic degradation. Objective This study aimed to investigate the effect of laser diode irradiation on the degree of conversion (DC), water sorption (WS), and water solubility (WSB) of these bonding systems in an attempt to improve their physico-mechanical resistance. Material and Methods Two bonding agents were tested: a two-step total-etch system [Adper™ Single Bond 2, 3M ESPE (SB)] and a universal system [Adper™ Single Bond Universal, 3M ESPE (SU)]. Square-shaped specimens were prepared and assigned into 4 groups (n=5): SB and SU (control groups – no laser irradiation) and SB-L and SU-L [SB and SU laser (L) – irradiated groups]. DC was assessed using Fourier transform infrared spectroscopy with attenuated total reflectance. Additional uncured resin samples (≈3.0 µL, n=5) of each adhesive were also scanned for final DC calculation. For WS/WSB tests, similar specimens (n=10) were prepared and measured by monitoring the mass changes after dehydration/water storage cycles. For both tests, adhesive fluids were dropped into standardized Teflon molds (6.0×6.0×1.0 mm), irradiated with a 970-nm laser diode, and then polymerized with an LED-curing unit (1 W/cm2). Results Laser irradiation immediately before photopolymerization increased the DC (%) of the tested adhesives: SB-L>SB>SU-L>SU. For WS/WSB (μg/mm3), only the dentin bonding system (DBS) was a significant factor (p<0.05): SB>SU. Conclusion Irradiation with a laser diode improved the degree of conversion of all tested simplified dentin bonding systems, with no impact on water sorption and solubility. PMID:28877276

  10. Validation of a Cariogenic Biofilm Model to Evaluate the Effect of Fluoride on Enamel and Root Dentine Demineralization

    PubMed Central

    2016-01-01

    Due to gingival recession both enamel and root dentine are at risk of developing caries. Both tissues are exposed to a similar environment, however there is not a validated model to evaluate the effect of fluoride on these dental substrates simultaneously. Hence, this study aimed to validate a caries model to evaluate the effect of fluoride to prevent demineralization on enamel and root-dentine. Streptococcus mutans UA159 biofilms were formed on saliva-coated bovine enamel and root dentine slabs (n = 12 per group) mounted in the same well of culture plates. The biofilms were exposed 8×/day to 10% sucrose and treated 2×/day with fluoridated solutions containing 0, 150, 450, or 1,350 ppm F; thus, simulating the use of low to high fluoride concentration toothpastes. The pH values of the culture medium was monitored 2×/day as a biofilm acidogenicity indicator. After 96 h, biofilms were collected for fluoride concentration analysis. The percentage of surface hardness loss (%SHL) was calculated for slabs. The fluoride uptake by the enamel and dentine was also determined. The model showed a dose-response because the biofilm and fluoride uptake increased and %SHL decreased at increasing fluoride concentrations (p < 0.05). Fluoride in the biofilm formed on dentine and fluoride uptake by dentine were higher than those for enamel. With the same fluoride concentration treatment, the percentage of reduction of demineralization was lower for dentine than for enamel. In conclusion, the model was validated in terms of a dose-response effect of fluoride on enamel and root dentine. Furthermore, the findings support the clinical data, suggesting that higher fluoride concentrations are necessary to control caries of root dentine than of enamel. PMID:26731743

  11. Ablation rate and morphology of superficial and deep dentin irradiated with different Er:YAG laser energy levels.

    PubMed

    Raucci-Neto, Walter; Chinelatti, Michelle Alexandra; Palma-Dibb, Regina Guenka

    2008-12-01

    In this study we evaluated the ablation rate of superficial and deep dentin irradiated with different Er:YAG laser energy levels, and observed the micromorphological aspects of the lased substrates with a scanning electron microscope (SEM). Little is known about the effect of Er:YAG laser irradiation on different dentin depths. Sixty molar crowns were bisected, providing 120 specimens, which were randomly assigned into two groups (superficial or deep dentin), and later into five subgroups (160, 200, 260, 300, or 360 mJ). Initial masses of the specimens were obtained. After laser irradiation, the final masses were obtained and mass losses were calculated followed by the preparation of specimens for SEM examination. Mass-loss values were subjected to two-way ANOVA and Fisher's least significant difference multiple-comparison tests (p > 0.05). There was no difference between superficial and deep dentin. A significant and gradual increase in the mass-loss values was reached when energies were raised, regardless of the dentin depth. The energy level of 360 mJ showed the highest values and was statistically significantly different from the other energy levels. The SEM images showed that deep dentin was more selectively ablated, especially intertubular dentin, promoting tubule protrusion. At 360 mJ the micromorphological features were similar for both dentin depths. The ablation rate did not depend on the depth of the dentin, and an energy level lower than 360 mJ is recommended to ablate both superficial and deep dentin effectively without causing tissue damage.

  12. Effect of stress and temperature on the micromechanics of creep in highly irradiated bone and dentin.

    PubMed

    Singhal, Anjali; Deymier-Black, Alix C; Almer, Jonathan D; Dunand, David C

    2013-04-01

    Synchrotron X-ray diffraction is used to study in situ the evolution of phase strains during compressive creep deformation in bovine bone and dentin for a range of compressive stresses and irradiation rates, at ambient and body temperatures. In all cases, compressive strains in the collagen phase increase with increasing creep time (and concomitant irradiation), reflecting macroscopic deformation of the sample. By contrast, compressive elastic strains in the hydroxyapatite (HAP) phase, created upon initial application of compressive load on the sample, decrease with increasing time (and irradiation) for all conditions; this load shedding behavior is consistent with damage at the HAP-collagen interface due to the high irradiation doses (from ~100 to ~9,000 kGy). Both the HAP and fibril strain rates increase with applied compressive stress, temperature and irradiation rate, which is indicative of greater collagen molecular sliding at the HAP-collagen interface and greater intermolecular sliding (i.e., plastic deformation) within the collagen network. The temperature sensitivity confirms that testing at body temperature, rather than ambient temperature, is necessary to assess the in vivo behavior of bone and teeth. The characteristic pattern of HAP strain evolution with time differs quantitatively between bone and dentin, and may reflect their different structural organization.

  13. Morphological alterations in dentine after mechanical treatment and ultrashort pulse laser irradiation.

    PubMed

    Portillo Muñoz, María; Lorenzo Luengo, María Cruz; Sánchez Llorente, José Miguel; Peix Sánchez, Manuel; Albaladejo, Alberto; García, Ana; Moreno Pedraz, Pablo

    2012-01-01

    The aim of this study was to evaluate and compare the morphological changes that occur in dentine after femtosecond laser irradiation and after mechanical treatment. The duration of the laser pulse is an important parameter, because within the time frame of the pulse heat diffusion plays a very important role in the mechanism of interaction between the light and the tissue. Six totally impacted human third molars were sectioned into sheets approximately 1 mm thick with an Accutom-50 precision cutting machine. The samples were randomly divided into two groups according to their cavity preparation: mechanical cavity preparation and laser cavity preparation. The samples were then examined by light microscopy and scanning electron microscopy. There were clear differences in the results obtained with the two techniques. Cavities prepared with the laser with pulses of <1 ps showed no microcracks, and the treated surface displayed a rough and irregular aspect with no smear layer and exhibited open dentinal tubules. On the contrary, cavities made with a rotatory instrument had a smooth surface and microcracks, a broad area of carbonization and merging, occluded dentinal tubules and a smear layer. This study showed that human dentine can be successfully ablated with the ultrashort pulse laser.

  14. Effect of dentin thickness on root surface temperature of teeth undergoing ultrasonic removal of posts.

    PubMed

    Horan, Brooks B; Tordik, Patricia A; Imamura, Glen; Goodell, Gary G

    2008-04-01

    The purpose of this study was to measure root surface temperature changes on thin-rooted and thick-rooted teeth undergoing ultrasonic vibration of cemented posts, with and without irrigation. Twenty-four single canal teeth were decoronated, length standardized, instrumented, obturated, and cemented with prefabricated posts. The teeth were divided into thin-rooted or thick-rooted groups. Thermocouples were cemented to the external proximal root surfaces adjacent the post ends. The roots were then mounted in standardized plaster molds and placed in a temperature-controlled water bath. Posts were ultrasonically vibrated with and without irrigation, and external root temperatures were recorded from an initial 37 degrees C baseline for a period of 4 minutes. The data were analyzed with the Student t test at alpha = .05. No significant differences were found in temperature change between the thin-rooted and thick-rooted groups, with or without irrigation. Linear regression and correlation analysis revealed no relationship between dentin thickness and temperature change.

  15. Marginal adaptation of newer root canal sealers to dentin: A SEM study

    PubMed Central

    Polineni, Swapnika; Bolla, Nagesh; Mandava, Pragna; Vemuri, Sayesh; Mallela, Madhusudana; Gandham, Vijaya Madhuri

    2016-01-01

    Aim: This in vitro study evaluated and compared the marginal adaptation of three newer root canal sealers to root dentin. Materials and Methods: Thirty freshly extracted human single-rooted teeth with completely formed apices were taken. Teeth were decoronated, and root canals were instrumented. The specimens were randomly divided into three groups (n = 10) based upon the sealer used. Group 1 - teeth were obturated with epoxy resin sealer (MM-Seal). Group 2 - teeth were obturated with mineral trioxide aggregate (MTA) based sealer (MTA Fillapex), Group 3 - teeth were obturated with bioceramic sealer (EndoSequence BC sealer). Later samples were vertically sectioned using hard tissue microtome and marginal adaptation of sealers to root dentin was evaluated under coronal and apical halves using scanning electron microscopy (SEM) and marginal gap values were recorded. Results: The data were statistically analyzed by two-way ANOVA and Tukey's multiple post hoc test. The highest marginal gap was seen in Group 2 (apical-16680.00 nm, coronal-10796 nm) and the lowest marginal gap was observed in Group 1 (apical-599.42 nm, coronal-522.72 nm). Coronal halves showed superior adaptation compared to apical halves in all the groups under SEM. Conclusion: Within the limitations of this study epoxy resin-based MM-Seal showed good marginal adaptation than other materials tested. PMID:27563187

  16. Qualitative Time-of-Flight Secondary Ion Mass Spectrometry Analysis of Root Dentin Irrigated with Sodium Hypochlorite, EDTA, or Chlorhexidine.

    PubMed

    Kolosowski, Kamil P; Sodhi, Rana N S; Kishen, Anil; Basrani, Bettina R

    2015-10-01

    Sodium hypochlorite (NaOCl), chelating agents, and chlorhexidine (CHX), which are commonly used irrigants during endodontic treatment, have the potential to alter the physical and chemical properties of the dentin structure. The aim of this study was to use time-of-flight secondary ion mass spectrometry to qualitatively evaluate the chemical characteristics of dentin surface and compare it with dentin exposed to NaOCl, EDTA, or CHX. Four blocks of dentin from a root of a human maxillary molar were embedded in resin and trimmed with a microtome to expose the dentin. Samples were randomly assigned to 4 treatment groups: (1) no irrigation treatment (sample A), (2) 2.5% NaOCl (sample B), (3) 17% EDTA (sample C), and (4) 2% CHX (sample D). Dentin surfaces were analyzed by time-of-flight secondary ion mass spectrometry, which allowed characterization of dentin surface chemistry by both imaging and mass spectroscopic analysis obtained in high mass and spatial resolution modes. Sample A revealed intense peaks characteristics of hydroxyapatite in addition to Na(+), K(+), CH4N(+), CN(-), CNO(-), Mg(+), F(-), and HCO2(-) peaks. Sample B showed severely decreased CH4N(+) and increased intensity of Cl(-). Sample C lacked Ca(+) and Mg(+) and showed decreased PO2(-) and PO3(-). Sample D exhibited a distinct presence of CHX. The spectral image of sample A displayed even distribution of Na(+) and Ca(+) on a smeared surface. The surfaces of samples B and D had patent dentinal tubules, whereas sample D showed an intense CHX signal. Sample C had some patent dentinal tubules and lacked Ca(+). NaOCl removed protein components from the dentin matrix, EDTA removed calcium and magnesium ions from the dentin, and CHX formed an adsorbed layer on the dentin surface. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  17. Effect of QMix, peracetic acid and ethylenediaminetetraacetic acid on calcium loss and microhardness of root dentine

    PubMed Central

    Taneja, Sonali; Kumari, Manju; Anand, Surbhi

    2014-01-01

    Objectives: The objective of this in vitro study was to assess the effect of different chelating agents on the calcium loss and its subsequent effect on the microhardness of the root dentin. Materials and Methods: Ten single rooted lower premolars were selected. The teeth were decoronated and thick transverse sections of 2 mm were obtained from the coronal third of the root. Each section was then divided into four quarters, each part constituting a sample specimen from the same tooth for each group. The treatment groups were: Group 1 (Control): 5% Sodium hypochlorite (NaOCl) for 5 min + distilled water for 5 min; Group 2: 5% NaOCl for 5 min + 17% ethylenediaminetetraacetic acid (EDTA) for 5 min; Group 3: 5% NaOCl for 5 min + 2.25% Peracetic acid (PAA) for 5 min and Group 4: 5% NaOCl for 5 min + QMix for 5 min respectively. The calcium loss of the samples was evaluated using the Atomic Absorption Spectrophotometer followed by determination of their microhardness using Vickers Hardness Tester. Data was analyzed using one-way ANOVA, Post hoc Tukey test and Pearson correlation. Results: The maximum calcium loss and minimum microhardness was observed in Group 3 followed by Group 2, Group 4 and Group 1. There was a statistically significant difference between all the groups except between Groups 2 and 4. Conclusions: Irrigation with NaOCl + 2.25% PAA caused the maximum calcium loss from root dentin and reduced microhardness. A negative correlation existed between the calcium loss and reduction in the microhardness of root dentin. PMID:24778513

  18. Temperature rise after KTP:NdYAG laser irradiation as a root-planing complement

    NASA Astrophysics Data System (ADS)

    Nammour, S.; Kowalyk, Kenneth; Valici, Ch.; Guillaume, Patrick

    1997-05-01

    The purposes of this study was to define the optimal irradiation conditions of a KTP:NdYAG laser after root planning treatment. The surfaces of 40 single-root human teeth were scaled with conventional tools before lasing. The pulpal temperature increase was measured by means of a thermocouple. The influence of variables of coloration by Acid Red 52, scanning speed, dentin thickness, and probe position, have been analyzed for a constant exposure time of 15 seconds. The temperature was below 3 C for the adjustments, power output: 400 mw, scanning speed of irradiation: 2 mm/sec., and Pw 0.10 m sec, PRR < 60 Hz or Pw: 0.12 m sec, PRR < 55 Hz.

  19. Effect of Nd:YAG Laser Irradiation on the Number of Open Dentinal Tubules and Their Diameter with and without Smear of Graphite: An in Vitro Study.

    PubMed

    Maleki-Pour, Mohammad Reza; Birang, Reza; Khoshayand, Maryam; Naghsh, Narges

    2015-01-01

    Dentin hypersensitivity (DH) is characterized by tooth pain arising from exposure of dental roots. In this study the efficiency of neodymium yttrium-aluminum-garnet (Nd:YAG) laser in association with graphite on dentinal surface changes as the alternative to the treatment of DH was evaluated. Sixteen noncarious human third molars were collected and sectioned into 5 parts from cementoenamel junction (CEJ) to the furcation area. The prepared samples were randomly assigned into five groups (Gs) of each 16: Control (G1), treated by Nd:YAG laser at 0.5 W (G2), irradiation of Nd:YAG with a 0.25 W output power(G3), smeared with graphite and then using Nd:YAG laser at output powers of 0.5 W (G4) and 0.25 W (G5). For all groups the parameters were 15 Hz, 60 s, at two stages and with a right angle irradiation. The number and diameter of dentinal tubules (DT) were compared and analyzed by SPSS software, One way ANOVA and Post hoc LSD tests. The number of open dentinal tubules varied significantly between all groups except among G1 with G3 and G2 with G5. Multiple comparison tests also exhibited significant differences regarding the diameter of tubules between the groups two by two except among G2 with G5. Nd:YAG laser used at 0.25 W and 0.5 W with application of graphite smear was able to reduce the number and diameter of dentinal tubules.

  20. Effect of Nd:YAG Laser Irradiation on the Number of Open Dentinal Tubules and Their Diameter with and without Smear of Graphite: An in Vitro Study

    PubMed Central

    Maleki-pour, Mohammad Reza; Birang, Reza; Khoshayand, Maryam; Naghsh, Narges

    2015-01-01

    Introduction: Dentin hypersensitivity (DH) is characterized by tooth pain arising from exposure of dental roots. In this study the efficiency of neodymium yttrium-aluminum-garnet (Nd:YAG) laser in association with graphite on dentinal surface changes as the alternative to the treatment of DH was evaluated. Methods: Sixteen noncarious human third molars were collected and sectioned into 5 parts from cementoenamel junction (CEJ) to the furcation area. The prepared samples were randomly assigned into five groups (Gs) of each 16: Control (G1), treated by Nd:YAG laser at 0.5 W (G2), irradiation of Nd:YAG with a 0.25 W output power(G3), smeared with graphite and then using Nd:YAG laser at output powers of 0.5 W (G4) and 0.25 W (G5). For all groups the parameters were 15 Hz, 60 s, at two stages and with a right angle irradiation. The number and diameter of dentinal tubules (DT) were compared and analyzed by SPSS software, One way ANOVA and Post hoc LSD tests. Results:The number of open dentinal tubules varied significantly between all groups except among G1 with G3 and G2 with G5. Multiple comparison tests also exhibited significant differences regarding the diameter of tubules between the groups two by two except among G2 with G5. Conclusion: Nd:YAG laser used at 0.25 W and 0.5 W with application of graphite smear was able to reduce the number and diameter of dentinal tubules. PMID:25699166

  1. Morphological assessment of dentine and cementum following apicectomy with Zekrya burs and Er:YAG laser associated with direct and indirect Nd:YAG laser irradiation.

    PubMed

    de Moura, Abilio Albuquerque Maranhão; Moura-Netto, Cacio; Barletta, Fernando Branco; Vieira-Júnior, Nilson Dias; Eduardo, Carlos de Paula

    2010-04-01

    This study aimed to assess the apical surface morphology of maxillary central incisors resected 3.0 mm from the tooth apex using Zekrya burs or Er:YAG laser, with or without subsequent direct Nd:YAG laser irradiation (apical and buccal surfaces) and indirect irradiation (palatal surface). Forty maxillary central incisors were instrumented and obturated. The roots were divided into 4 groups according to the root resection method (Zekrya bur or Er:YAG laser - 1.8 W, 450 mJ, 4 Hz, 113 J/cm(2)) and further surface treatment (none or Nd:YAG laser - 2.0 W, 100 mJ, 20 Hz, 124 J/cm(2)). The teeth were prepared for SEM analysis. Scores ranging from 1 to 4 were attributed to cut quality and morphological changes. The data were analyzed by the Kruskal-Wallis test and by Dunn's test. SEM images showed irregular surfaces on the apical portions resected with Zekrya burs, with smear layer and grooves in the resected dentine and slight gutta-percha displacement and plasticization. On the other hand, apicectomies carried out with Er:YAG laser showed morphological changes compatible with ablated dentine, with rough surfaces and craters. In spite of the presence of plasticized gutta-percha, with the presence of bubbles, an irregular adaptation of the filling material to the root walls was also observed. Direct Nd:YAG laser irradiation of the apical and buccal surfaces of the resected roots resulted in areas of resolidification and fusion in the dentine and cementum, with a vitrified aspect; indirect Nd:YAG laser irradiation of the palatal surfaces yielded a lower number of changes in the cementum, with irregular resolidification areas. There were no differences in terms of cut quality between the use of burs and Er:YAG laser or between the 2 surfaces (apical and buccal) treated with Nd:YAG laser with direct irradiation. However, morphological changes were significantly less frequent on surfaces submitted to indirect irradiation (palatal) when compared with those directly irradiated

  2. Effect of diode laser radiation in root canal wall dentine: a microbiological study

    NASA Astrophysics Data System (ADS)

    Gutknecht, Norbert; Conrads, Georg; Apel, Christian; Schubert, Claus; Lampert, Friedrich

    2000-03-01

    The aim of this study was to investigate the antibacterial effect of a diode laser in deep root canal dentine. The microbial colonization of root canal dentine can lead to failures in conventional endodontic treatment if only an inadequate bacterial reduction is achieved through canal treatment and chemical disinfection. 100 micrometer, 300 micrometer and 500 micrometer bovine dentine slices obtained by longitudinal sections were sterilized and inoculated on one side with an Enterococcus faecalis suspension. Laser radiation was performed on the opposite side with the diode laser, emits light at 810 nm and operates in the continuous wave mode (cw). Radiation was performed using a 400 micrometer tapered fiber tip at an angle of approx. 5 degrees to the surface over a period of 30 s. The output power at the distal end of the tip was 0.6 watt. The bacteria were then eluted through vibration and cultured on blood agar plates. The colony count reflected the antibacterial effect of laser radiation as a function of the layer thickness. A mean bacterial reduction of 74% was achieved even with a 500 micrometer thick slice. This investigation indicates that the diode laser can support the bacterial reduction in endodontic treatment.

  3. Effect of Citric Acid and Ethylenediaminetetraacetic Acid on the Surface Morphology of Young and Old Root Dentin

    PubMed Central

    Scelza, Miriam Zaccaro; de Noronha, Fernando; da Silva, Licinio Esmeraldo; Maurício, Marcos; Gallito, Marco Antonio; Scelza, Pantaleo

    2016-01-01

    Introduction: The aim of this in vitro study was to evaluate the effect of 10% citric acid and 17% ethylenediaminetetraacetic acid (EDTA) irrigating solutions on the surface morphology of young and old root dentin by determining the number and diameter of dentinal tubules using scanning electron microscopy (SEM). Methods and Materials: Fifty healthy human teeth collected from young (≤30 years) and old (≥60 years) individuals (n=25) were first prepared with a Largo bur #2 to produce smear layer on the root canal surface. Subsequently, the crowns and the root middle and apical thirds were sectioned and removed, and the cervical thirds were sectioned vertically in the buccal-lingual direction into two equal halves. The obtained samples were then immersed in 2.5% sodium hypochlorite for 30 min and randomly separated into two treatment groups for each age group. In each age group, ten samples were selected as controls and did not receive any type of treatment. The rest of the specimens were then rinsed, dried and treated for 4 min with 10% citric acid or 17% EDTA. The samples were then assessed with SEM regarding the number and diameter of dentinal tubules. All data were assessed using Student’s t-test. The level of significance was set at 0.05. Results: Regardless of the type of treatment, no significant differences were observed in the number of open tubules between the young and old root dentin (P>0.05). Nonetheless, the diameter of the tubules in the old root dentin was larger when 17% EDTA was used (P<0.05). Both, young and old root dentin did not differ with the 10% citric acid treatment (P>0.05). Conclusion: The results showed that 17% EDTA treatment induced a significant demineralization in old root dentin. PMID:27471529

  4. Antibacterial Efficacy of Pastes Against E Faecalis in Primary Root Dentin: A Confocal Microscope Study.

    PubMed

    Verma, R; Sharma, D S; Pathak, A K

    2015-01-01

    Management of abscessed primary teeth often present endodontic failure owing to questioned efficiency of dressings or obturating pastes to eliminate Enterococcus faecalis, a resistant bacterium, residing in depth of dentinal tubules. The present study evaluates the antimicrobial efficacy of two antibacterial and two obturating pastes in dentinal tubules of primary teeth infected with Enterococcus faecalis using viability stain and confocal laser scanning microscope (CLSM). Total 28 samples were prepared.Four groups with 6 samples each were made according to antibacterial pastes i.e. 1% or 2%Chlorhexidine (CHX) + calcium hydroxide (CH), CH + iodoform (Metapex) and Zinc Oxide Eugenol (ZOE). Dentinal tubules from the root canal side were infected with E. faecalis by centrifugation of the bacterial suspension. Two specimens from each group were subjected to 1, 7 and 15 days antibacterial pastes exposure. Viability staining followed by CLSM were used to quantitatively analyze the dead cell count directly inside dentin. Univariate analysis showed that all medicaments were significantly effective (p<.05). Kruskal wallis ANOVA test did not show significant difference among four medicaments at day 1 while it was significantly different at day 7 & 15. Paired sample student's t-test revealed significant difference in efficacy between 1& 15 days for 1%CHX+CH; between 1&15,and 7&15 days; between all days for ZOE. Ranking of antimicrobial efficacy of tested medicament was (most effective to the least): 1%CHX+CH(15)> ZOE(15)> Metapex(15)> 2%CHX+CH(15)> 2%CHX+CH(7)> 2%CHX+CH(1)> 1%CHX+CH(7)> 2%CHX+CH(15)> Metapex(1)> ZOE(1)> ZOE(7). All medicaments were effective against E. faecalis in dentine of primary teeth and their efficacy increased with longer contact with 1%CHX+CH being most effective at day 15. Inclusion of 1% CHX in dressings or obturating pastes might minimize the endodontic relapse and maximize the tooth retention in functional state in pediatric dentistry.

  5. [The influence of the difference of caries detective methods on the bond strength for caries affected root canal dentin].

    PubMed

    Otake, Shiho

    2010-03-01

    Firm adhesion of composite resin and dentin is the basic premise for building up resin composite cores successfully. To assess the efficacy of several caries detective methods (stained with Caries Detector and probing with sharp probe) for caries affected root canal dentin, microtensile bond strengths of resin composite to caries-affected root canal dentin and failure mode distribution were analyzed in this study. Color and hardness were used for assessment of root caries as follows: Dye stain group (pale pink stained with Caries Detector), Probing group (probing with sharp probe) and Sound dentin group (Control). The bond strengths (mean +/- standard deviation) of the Probing group (64.6 +/- 11.9 MPa) and the Sound dentin group (68.7 +/- 11.1 MPa) were significantly higher than those of the Dye stain group (46.9 +/- 7.9 MPa, p<0.05). However, there is no significant difference in fracture mode between the Dye stain group and the Probing group (p<0.05). This could be attributed to that the thick smear layer caused a loss of hybrid layer strength. In conclusion, the caries removal technique of the root canal dentin affected the bond strength of the resin composite.

  6. Tensile Bond Strengths of Two Adhesives on Irradiated and Nonirradiated Human Dentin

    PubMed Central

    Bernard, Cécile; Abouelleil, Hazem; Gustin, Marie-Paule; Grosgogeat, Brigitte

    2015-01-01

    The aim of this study was to assess the effect of radiotherapy on bond efficiency of two different adhesive systems using tensile bond strength test. Twenty extracted teeth after radiotherapy and twenty nonirradiated extracted teeth were used. The irradiation was applied in vivo to a minimal dose of 50 Gy. The specimens of each group were randomly assigned to two subgroups to test two different adhesive systems. A three-step/etch-and-rinse adhesive system (Optibond FL) and a two-steps/self-etch adhesive system (Optibond XTR) were used. Composite buildups were performed with a nanohybrid composite (Herculite XTR). All specimens were submitted to thermocycling ageing (10000 cycles). The specimens were sectioned in 1 mm2 sticks. Microtensile bond strength tests were measured. Nonparametric statistical analyses were performed due to nonnormality of data. Optibond XTR on irradiated and nonirradiated teeth did not show any significant differences. However, Optibond FL bond strength was more effective on nonirradiated teeth than on irradiated teeth. Within the limitations of an in vitro study, it can be concluded that radiotherapy had a significant detrimental effect on bond strength to human dentin. However, it seems that adhesive choice could be adapted to the substrata. According to the present study, the two-steps/self-etch (Optibond XTR) adhesive system tested could be more effective on irradiated dentin compared to three-steps/etch-and-rinse adhesive system (Optibond FL). PMID:26783528

  7. Structural and Morphological Changes in Human Dentin after Ablative and Subablative Er:YAG Laser Irradiation

    PubMed Central

    Moosavi, Horieh; Ghorbanzadeh, Sajedeh; Ahrari, Farzaneh

    2016-01-01

    Introduction: This study investigated the influence of Erbium-Doped Yttrium Aluminum Garnet (Er:YAG) laser on microhardness, chemical composition and subsurface morphology of dentin cavity walls. Methods: Forty sound human premolars were selected and randomly assigned into four groups. Class V cavities were prepared either with an Er:YAG laser (groups 1 and 2; 15 Hz, 250 mJ for enamel, 10 Hz, 200 mJ for dentin) or with a high speed handpiece (groups 3 and 4). The specimens in groups 1 and 3 served as the control, whereas those in groups 2 and 4 were exposed to subablative laser irradiation following cavity preparation (10 Hz, 50 mJ). After bisecting the specimens, one half was subjected to microhardness assessment and the other half was evaluated by SEM-EDS analysis. Results: Microhardness was significantly greater in the specimens prepared by both ablative and subablative laser irradiation (group 2) than that of the bur-prepared cavities (groups 3 and 4) (P < 0.05). The quantity of calcium ion was significantly greater in cavities prepared by the Er:YAG laser (groups 1 and 2) compared to that of the bur cavities (groups 3 and 4) (P < 0.05). Subablative irradiation improved microhardness and weight percentage of calcium ion in both laser and bur cavities, but the difference was not significant compared to that of the relevant control group (P > 0.05). Conclusion: Cavity preparation with an Er:YAG laser could be considered as an alternative to the conventional method of drilling, as it enhances the mechanical and compositional properties of lased dentin, especially when combined by subablative irradiation. PMID:27330703

  8. The effect of different desensitizing agents on initial demineralization of human root dentin.

    PubMed

    Gernhardt, Christian Ralf; Aschenbach, Kristin; Bekes, Katrin; Schaller, Hans-Guenter

    2005-10-01

    The aim of this study was to determine the caries-protective effect of 3 different desensitizing agents (Seal & Protect 2.0, D/Sense 2, and Gluma Desensitizer) on root dentin in vitro. The root surfaces of 60 freshly extracted, caries-free human molars were used. After removing the cementum, the teeth were coated with an acid-resistant nail varnish, exposing 2 rectangular windows of 2 X 3 mm each on the root surface. One window served as an untreated control, and the other window was treated with 1 of the desensitizing agents. The specimens were randomly distributed among the following experimental groups: group A, D/Sense 2; group B, Seal & Protect 2.0; and group C, Gluma Desensitizer. Subsequently, all specimens were demineralized for 14 days with acidified gel (HEC, pH 4.8, 37 degrees C). Two dentinal slabs were cut from each window. The slabs were ground to a thickness of 80 microm and immersed in water. The demineralization depth was determined using a polarized light microscope. The nontreated control specimens showed lesions with a mean depth of 84.9 microm (+/- 6.0). In the specimens treated with the desensitizing agents, lesion depth was generally significantly reduced. Statistical analysis revealed significantly lower values for the specimens in group B in comparison with the others. Within the limitations of an in vitro investigation, it can be concluded that the demineralization of the root surface can be hampered by applying the desensitizing agents tested.

  9. Influence of endodontic sealer composition and time of fiber post cementation on sealer adhesiveness to bovine root dentin.

    PubMed

    Rosa, Ricardo Abreu da; Barreto, Mirela Sangoi; Moraes, Rafael do Amaral; Broch, Juliana; Bier, Carlos Alexandre Souza; Só, Marcus Vinícius Reis; Kaizer, Osvaldo Bazzan; Valandro, Luiz Felipe

    2013-01-01

    This study aimed to assess the influence of the type of endodontic sealer (salicylate resin-based sealer vs. two endodontic sealers) and the time of fiber post cementation after root filling on the post adhesion to bovine root dentin. Sixty bovine roots were assigned to six groups (n=10), considering an experimental design with two factors (factorial 3x2): endodontic sealer factor in three levels [epoxy resin-based sealer (AH Plus), eugenol-based sealer (Endofill), and salicylate resin-based sealer plus mineral trioxide aggregate - MTA (MTA Fillapex)] and time for post cementation factor in two levels (immediate post cementation or 15 days after root canal filling). After post cementation, 2-mm-thick slices were produced and submitted to push-out test. The failure modes were analyzed under a 40× stereomicroscope and scored as: adhesive at cement/dentin interface; adhesive at cement/post interface; cement cohesive; post cohesive; dentin cohesive; or mixed. Data were analyzed using two-way ANOVA and Tukey's post-hoc tests (α=0.05). When the fiber posts were cemented immediately after the root canal filling, the bond strengths were similar, independent of the endodontic sealer type. However, after 15 days, the epoxy resin-based sealer presented higher bond strength than the other sealers (p<0.05). Comparison between each sealer in different experimental times did not reveal any differences. The main failure type was adhesive at dentin/cement interface (89.4%). The time elapsed between the root canal filling and post cementation has no influence on post/root dentin adhesion. On the contrary, the type of endodontic sealer can influence the adhesion between fiber posts and root dentin.

  10. The radicular dentine temperature during laser irradiation: an experimental study.

    PubMed

    Simeone, D; Gallet, P; Papini, F; Cerisier, P

    1996-02-01

    The detoxification and sterilization radicular surfaces that have been produced by periodontal diseases could be accomplished after polishing (root planing) using the thermal elevation resulting from CO2 laser on continuous emission. In vitro experiments reveal that thermal elevations reached on the surfaces or in the depth are proportional to the dispersed energy. The thermal elevation in the depth (0.5-1 mm from the impact point) remained moderate because of the water absorption potentials of the radiations. Energies from 2 to 4.5 J can help obtain the combination of surface temperature elevation, which allows detoxification, and of a thermal elevation in the depth, compatible with vital tissues. This energy has to be delivered at an application time under 0.6 sec in continuous mode.

  11. Does laser diode irradiation improve the degree of conversion of simplified dentin bonding systems?

    PubMed

    Brianezzi, Leticia Ferreira de Freitas; Maenosono, Rafael Massunari; Bim, Odair; Zabeu, Giovanna Speranza; Palma-Dibb, Regina Guenka; Ishikiriama, Sérgio Kiyoshi

    2017-01-01

    This study aimed to investigate the effect of laser diode irradiation on the degree of conversion (DC), water sorption (WS), and water solubility (WSB) of these bonding systems in an attempt to improve their physico-mechanical resistance. Two bonding agents were tested: a two-step total-etch system [Adper™ Single Bond 2, 3M ESPE (SB)] and a universal system [Adper™ Single Bond Universal, 3M ESPE (SU)]. Square-shaped specimens were prepared and assigned into 4 groups (n=5): SB and SU (control groups - no laser irradiation) and SB-L and SU-L [SB and SU laser (L) - irradiated groups]. DC was assessed using Fourier transform infrared spectroscopy with attenuated total reflectance. Additional uncured resin samples (≈3.0 µL, n=5) of each adhesive were also scanned for final DC calculation. For WS/WSB tests, similar specimens (n=10) were prepared and measured by monitoring the mass changes after dehydration/water storage cycles. For both tests, adhesive fluids were dropped into standardized Teflon molds (6.0×6.0×1.0 mm), irradiated with a 970-nm laser diode, and then polymerized with an LED-curing unit (1 W/cm2). Laser irradiation immediately before photopolymerization increased the DC (%) of the tested adhesives: SB-L>SB>SU-L>SU. For WS/WSB (μg/mm3), only the dentin bonding system (DBS) was a significant factor (p<0.05): SB>SU. Irradiation with a laser diode improved the degree of conversion of all tested simplified dentin bonding systems, with no impact on water sorption and solubility.

  12. Differential hydrolytic degradation of dentin bonds when luting carbon fiber posts to the root canal.

    PubMed

    Montanari, Marco; Prati, Carlo; Piana, Gabriela

    2011-05-01

    The purpose of the study was to evaluate the effect of water storage, adhesive system and root canal region on the hydrolytic degradation of dentin bonds to carbon fiber posts. Fiber posts were bonded to the root canals using different adhesive systems and composites: SB1 XT group (Scotchbond 1 XT/RelyX ARC), OBF group (One Up Bond F Plus/Ionotite F), and AB2 group (All Bond 2/C&B) After water storage (10 days), all roots were sectioned into 1 mm beams and divided into coronal or apical group. The specimens were stored in water at 22-26 °C temperature for 15 or 60 days and tested for microtensile bond strength at a crosshead speed of 0.9 mm/min after the calculation of the bonding area. Statistical analysis was performed with ANOVA followed by Tukey test to detect differences between groups (α=0.05). SEM investigation was performed to determine the mode of fracture. Bond strength at coronal and apical half showed significant differences between experimental groups both after 15 and 60 days of water storage. Premature failures were observed in 16-20% of specimens before storage in water. For the bonding systems tested, clinicians should consider that bond strength inside the root canal at apical half is lower than at coronal half irrespective of the adhesive system. The adhesion within the root canal is possible for SB1 XT and OBF groups unlike the AB2 group where adhesion to root canal dentine is not reliable. Nevertheless, apical half represents the worst scenario in which is possible to obtain a durable adhesion.

  13. Incidence of Dentinal Cracks after Root Canal Preparation with Twisted File Adaptive Instruments Using Different Kinematics.

    PubMed

    Karataş, Ertuğrul; Arslan, Hakan; Alsancak, Meltem; Kırıcı, Damla Özsu; Ersoy, İbrahim

    2015-07-01

    The purpose of the present study was to assess the effect of root canal instrumentation using Twisted File Adaptive instruments (Axis/SybronEndo, Orange, CA) with different kinematics (adaptive motion, 90° clockwise [CW]-30° counterclockwise [CCW], 150° CW-30° CCW, 210° CW-30° CCW, and continuous rotation) on crack formation. One hundred five mandibular central incisor teeth were selected. Fifteen teeth were left unprepared (control group), and the remaining 90 teeth were assigned to the 5 root canal shaping groups as follows (n = 15): adaptive motion, 90° CW-30° CCW, 150° CW-30° CCW, 210° CW-30° CCW, continuous rotation, and hand file. All the roots were sectioned horizontally at 3, 6, and 9 mm from the apex with a low-speed saw under water cooling, and the slices were then viewed through a stereomicroscope at 25× magnification. Digital images of each slice were captured using a camera to determine the presence of dentinal cracks. No cracks were observed in the control group, and the continuous rotation group had more cracks than the reciprocation groups (90° CW-30° CCW, 150° CW-30° CCW, and 210° CW-30° CCW) (P < .05). Both the continuous rotation and adaptive motion groups had significantly more dentinal cracks than the hand file group (P < .05). Regarding the different sections (3, 6, and 9 mm), there was a significant difference between the experimental groups at the 9-mm level (P < .05). The incidence of dentinal cracks is less with TF Adaptive instruments working in 210° CW-30° CCW reciprocating motion compared with working in continuous rotation and adaptive motion. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  14. Combined Antibacterial Effect of Sodium Hypochlorite and Root Canal Sealers against Enterococcus faecalis Biofilms in Dentin Canals.

    PubMed

    Du, Tianfeng; Wang, Zhejun; Shen, Ya; Ma, Jingzhi; Cao, Yingguang; Haapasalo, Markus

    2015-08-01

    The present study aimed to evaluate the antibacterial effect of the combined use of sodium hypochlorite (NaOCl) and root canal sealers on Enterococcus faecalis biofilms using a dentin infection model. Cells of E. faecalis were introduced into the dentinal tubules by centrifugation and incubated in brain-heart infusion for 3 weeks. The biofilms in dentin were first subjected to 5% NaOCl or sterile water for 10 minutes followed by an equal thickness of AH Plus (Dentsply International Inc, York, PA), Endosequence BC Sealer (Brasseler USA, Savannah, GA), or MTA Fillapex (Angelus Indústria de Produtos Odontológicos S/A, Londrina, Brazil) placed on the root canal wall of the dentin specimens for 7, 30, and 60 days. Gutta-percha and water were used in a similar manner as controls. The proportions of dead and live bacteria inside the dentinal tubules were assessed by confocal laser scanning microscopy and viability staining. The combined use of NaOCl and sealers (30 and 60 days) killed significantly more bacteria than NaOCl or sealers alone (P < .05). NaOCl + MTA Fillapex was the most effective antibacterial combination by killing 83% bacteria in dentin tubules in 60 days. Thirty and 60 days of exposure to the sealers resulted in significantly more dead bacteria in dentin biofilms than 7-day exposures (P < .05). The placement of root canal sealer after NaOCl treatment enhanced antibacterial effects against E. faecalis in the dentinal tubules. Little additional effect was obtained after 30 days of exposure to sealers. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  15. Penetration of Sodium Hypochlorite Modified with Surfactants into Root Canal Dentin.

    PubMed

    Palazzi, Flavio; Blasi, Andrea; Mohammadi, Zahed; Del Fabbro, Massimo; Estrela, Carlos

    2016-01-01

    The aim of this study was to evaluate the effect of concentration, exposure time and temperature of sodium hypochlorite (NaOCl) added with surfactants on its penetration into dentinal tubules. Sixty-five extracted human permanent maxillary anterior teeth with single canals were prepared by ProTaper SX hand-operated instruments. The teeth were then sectioned perpendicular to the long axis. The crowns and apical thirds of all the teeth were removed. The remaining roots were processed into 4-mm-long blocks and stained overnight in crystal violet. One hundred and thirty stained blocks were further split into halves and treated by nine different types of NaOCl-based solutions. Three solutions were added with surfactants (Hypoclean, H6, Chlor-Xtra) and the others were regular hypochlorites at increasing concentrations (1%, 2%, 4%, 5.25%, <6%, 6% NaOCl) from different brands. The dentin blocks were exposed to the solutions for 2, 5, and 20 min at 20 °C, 37 °C and 45 °C, respectively. The depth of NaOCl penetration was determined by bleaching of the stain and measured by light microscopy at 20x and 40x. Statistical comparisons were made by using a generalized linear model with Bonferroni's post-hoc correction. The shortest penetration (81±6.6 μm) was obtained after incubation in 1% NaOCl for 2 min at 20 °C; the highest penetration (376.3±3.8 μm) was obtained with Chlor-Xtra for 20 min at 45 °C. Varying NaOCl concentration produced a minimal effect while temperature and exposure time had a significant direct relationship with NaOCl penetration into dentinal tubules, especially those with lowered surface tension. The exposure time and temperature of sodium hypochlorite as well as the addition of surfactants may influence the penetration depth of irrigants into dentinal tubules.

  16. Effect of gutta-percha solvents on mineral contents of human root dentin using ICP-AES technique.

    PubMed

    Erdemir, Ali; Eldeniz, Ayçe Unverdi; Belli, Sema

    2004-01-01

    The purpose of this in vitro study was to evaluate the mineral contents of root-canal dentin before and after treatment with two commonly used gutta-percha solvents: chloroform and halothane. Twenty extracted human premolars, whose crowns and apical thirds had been removed, were used. Pulp tissues were removed and the teeth were randomly divided into two groups including 10 teeth each. Root canals were enlarged with Gates Glidden burs (#1, 2, and 3). Dentin chips were obtained and saved in plates to serve as a control. Root-canal-dentin walls were then treated with chloroform or halothane for 15 min. Dentin chips were again obtained using Gates Glidden burs (#4, 5, and 6). The levels of five elements, calcium, phosphorus, magnesium, potassium, and sulfur, in each specimen were analyzed using ICP-AES (inductively coupled plasma atomic emission spectrometry) technique. Changes in the levels of the chemical elements were recorded. Differences between the groups were statistically analyzed using Mann-Whitney U test. There was a significant decrease in Ca level and significant increase in Mg level after treatment with halothane (p < 0.05). There was a significant increase in Mg level after treatment with chloroform. The changes in other elements levels after treatment with gutta-percha solvents were minimal and statistically not significant (p > 0.05). As a result it was concluded that gutta-percha solvents have effect on mineral contents of root dentin.

  17. Comparison of Endodontic Medicaments on Bond Strength of Fiber Post to Root Dentin Using Resin Cement

    PubMed Central

    Zare Jahromi, Maryam; Barekatain, Mehrdad; Ravanbod, Shirin; Ranjbarian, Parisa; Kousehlar, Sara

    2017-01-01

    Statement of the Problem: Endodontic irrigants and medicaments may affect the bond strength of intracanal posts to root dentin. Purpose: The aim of this study was to compare the effect of calcium hydroxide (Ca(OH)2) and 2% chlorhexidine gel (CHX) on bond strength of fiber post cemented with resin cement to root dentin. Materials and Method: This in vitro experimental study was conducted on 36 mandibular premolars. Canals were prepared using the step back technique. After root canal irrigation, the teeth were divided into three groups of 12. Ca(OH)2 paste and CHX gel were used as intracanal medicaments in the first and second groups respectively. No intracanal medicament was used in the third group (control group). Access cavities were then sealed and the teeth were incubated for one week. The root canals were then filled using gutta percha and AH26 sealer and the teeth were incubated for 72 hours. Tooth crowns were then cut at the level of the cementoenamel junction and intracanal posts were placed. The teeth were mounted in auto-polymerizing acrylic resin, and incubated for one week .They were then sectioned into 1.5mm thick slices from their coronal surface using a fully automated cutting machine, and subjected to push-out test until failure. The load at debonding was recorded and data were analyzed using one-way ANOVA, post-hoc test and t-test. The coronal margin of the root was at the level of the surface of acrylic resin in the mold. Results: The mean bond strength was 4.45 MPa in the Ca(OH)2, 2.45 MPa in the CHX and 2.48 MPa in the control group. The difference in this regard was statistically significant among groups (p= 0.04). The Ca(OH)2 group had significant differences with the CHX and control groups (p= 0.03 and p= 0.02, respectively). The difference between the CHX and control groups was not significant (p= 0.974). Conclusion: Based on the results, Ca(OH)2 increased the bond strength of fiber post to root dentin but 2% CHX had no effect on bond

  18. Evaluation of dentinal defects during root canal preparation using thermomechanically processed nickel-titanium files

    PubMed Central

    Kesim, Bertan; Sagsen, Burak; Aslan, Tugrul

    2017-01-01

    Objective: The aim of this study was to compare the incidence of root cracks after root canal instrumentation with thermomechanically processed nickel-titanium (Ni-Ti) files with different instrumentation kinematics. Materials and Methods: A total of 150 extracted mandibular premolars with mature apices and straight root canals were divided into five groups and used in this study. In Group 1, 30 teeth were prepared using hand K-files and assigned to control group, Group 2 was instrumented using K3XF Rotary files (SybronEndo, Glendora, CA, USA) with continuous rotary motion. The teeth in Group 3 were instrumented by ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland) rotary files which make asymmetric rotary motion, In Group 4, teeth were instrumented by RECIPROC (VDW, Munich, Germany) with reciprocation motion and in Group 5, teeth were instrumented by Twisted File (TF) Adaptive (SybronEndo, Orange, CA, USA) files that use combination of continuous rotation and reciprocation motion (n = 30/per group). All the roots were horizontally sectioned 3, 6, and 9 mm from the apex with a low speed saw under water cooling. Then, the slices were examined through a stereomicroscope to determine the presence of dentinal microcracks. Results: For the apical (3-mm) and coronal (9-mm) sections, the ProTaper Next and TF Adaptive produced significantly more cracks than the hand files, RECIPROC, and K3XF (P < 0.05). There was no significant difference between the experimental groups and control group at the 6-mm level (P > 0.05). Conclusions: Within the limitations of this in vitro study, all thermal-treated Ni-Ti instruments and hand files caused microcracks in root canal dentin. PMID:28729785

  19. Evaluation of dentinal defects during root canal preparation using thermomechanically processed nickel-titanium files.

    PubMed

    Kesim, Bertan; Sagsen, Burak; Aslan, Tugrul

    2017-01-01

    The aim of this study was to compare the incidence of root cracks after root canal instrumentation with thermomechanically processed nickel-titanium (Ni-Ti) files with different instrumentation kinematics. A total of 150 extracted mandibular premolars with mature apices and straight root canals were divided into five groups and used in this study. In Group 1, 30 teeth were prepared using hand K-files and assigned to control group, Group 2 was instrumented using K3XF Rotary files (SybronEndo, Glendora, CA, USA) with continuous rotary motion. The teeth in Group 3 were instrumented by ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland) rotary files which make asymmetric rotary motion, In Group 4, teeth were instrumented by RECIPROC (VDW, Munich, Germany) with reciprocation motion and in Group 5, teeth were instrumented by Twisted File (TF) Adaptive (SybronEndo, Orange, CA, USA) files that use combination of continuous rotation and reciprocation motion (n = 30/per group). All the roots were horizontally sectioned 3, 6, and 9 mm from the apex with a low speed saw under water cooling. Then, the slices were examined through a stereomicroscope to determine the presence of dentinal microcracks. For the apical (3-mm) and coronal (9-mm) sections, the ProTaper Next and TF Adaptive produced significantly more cracks than the hand files, RECIPROC, and K3XF (P < 0.05). There was no significant difference between the experimental groups and control group at the 6-mm level (P > 0.05). Within the limitations of this in vitro study, all thermal-treated Ni-Ti instruments and hand files caused microcracks in root canal dentin.

  20. Polymerization efficiency through translucent and opaque fiber posts and bonding to root dentin.

    PubMed

    Reginato, Cássia F; Oliveira, Aline S; Kaizer, Marina R; Jardim, Patrícia S; Moraes, Rafael R

    2013-01-01

    To investigate the polymerization efficiency through translucent and opaque glass fiber posts and the bond strength of a self-adhesive resin to root dentin. Translucent and opaque silanated conical posts, identical in length, diameter and shape (n=8), were cemented to incisor bovine roots using RelyX Unicem Clicker. Photoactivation was performed only through the posts. The roots were transversally sectioned (cervical, middle and apical thirds) and the push-out test was carried out. Data were analyzed using two-way ANOVA and Fisher's LSD method (5%). Failure modes were classified under magnification. An elastomer mold of a bovine incisor root was filled with flowable composite and the posts inserted into the mold. After photoactivation through the post and removal of unpolymerized material, the polymerization efficiency was estimated by percentage of mass gain (n=5). Data were analyzed using t-test (5%). The bond strength of the translucent post was higher than the opaque post for all root thirds. For both posts the bond strength at the cervical third was higher than at the middle and apical thirds. A predominance of adhesive failures was detected for all conditions. Mixed failures were more frequently observed for the opaque post. Almost all the composite polymerized and bonded to the extension of the translucent post, whereas polymerization of the composite was restricted to the cervical area of the opaque post. The use of translucent post may positively influence the polymerization efficiency and bond strength of resin cement to intraradicular dentin. Copyright © 2012 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  1. In vitro fracture resistance of root-filled teeth using new-generation dentine bonding adhesives.

    PubMed

    Hürmüzlü, F; Serper, A; Siso, S H; Er, K

    2003-11-01

    To compare the fracture resistance of root-filled premolar teeth restored with new-generation dentine bonding adhesives. Sixty extracted single-rooted human maxillary premolar teeth were used. Access cavities were prepared, and the roots were instrumented with K-files to an apical size 50 using a step-back technique. Root fillings were accomplished using gutta percha (Sure-Endo, Seoul, Korea) and AH Plus root canal sealer (Dentsply DeTrey, Konstanz, Germany) using the lateral condensation technique. The teeth were then randomly divided into six groups of 10 teeth each. A mesiodistocclusal (MOD) cavity was prepared in the teeth to the level of the canal orifices so that the thickness of the buccal wall of the teeth measured 2 mm at the occlusal surface and 3 mm at the cemento-enamel junction. Preparations were restored using the following adhesive systems: Etch & Prime 3.0 (Degussa AG, Hanau, Germany), Clearfil SE Bond (Kuraray, Osaka, Japan), Prompt L-Pop (ESPE, Seefeld, Germany), Panavia F (Kuraray, Osaka, Japan), Optibond Plus (Kerr, Orange, CA, USA) and Admira Bond (Voco, Cuxhaven, Germany); all preparations except those of the Panavia F and Admira Bond groups were further restored with resin composites. The Panavia F group was restored with amalgam and the Admira Bond group with Ormocer (Voco, Cuxhaven, Germany). The teeth were mounted in a Universal Testing Machine (Hounsfield, Surrey, UK), and the buccal walls were subjected to a slowly increasing compressive force until fracture occurred. The force of fracture of the walls of each tooth was recorded and the results in the various groups were compared. Statistical analysis of the data was accomplished using one-way anova. There was no significant difference in the fracture resistance of any of the test groups. In this laboratory study, the type of dentine bonding agents had no influence in the fracture resistance of teeth.

  2. Relationship between the chemical and morphological characteristics of human dentin after Er:YAG laser irradiation.

    PubMed

    Soares, Luís Eduardo Silva; Martin, Ovídio César Lavesa; Moriyama, Lilian Tan; Kurachi, Cristina; Martin, Airton Abrahão

    2013-06-01

    The effects of laser etching on dentin are studied by microenergy-dispersive x-ray fluorescence spectrometry (μ-EDXRF) and scanning electron microscopy (SEM) to establish the correlation of data obtained. Fifteen human third molars are prepared, baseline μ-EDXRF mappings are performed, and ten specimens are selected. Each specimen received four treatments: acid etching (control-CG) or erbium:yttrium-aluminum-garnet (Er:YAG) laser irradiation (I-100 mJ, II-160 mJ, and III-220 mJ), and maps are done again. The Ca and P content are significantly reduced after acid etching (p<0.0001) and increased after laser irradiation with 220 mJ (Ca: p<0.0153 and P: p=0.0005). The Ca/P ratio increased and decreased after CG (p=0.0052) and GI (p=0.0003) treatments, respectively. CG treatment resulted in lower inorganic content (GI: p<0.05, GII: p<0.01, and GIII: p<0.01) and higher Ca/P ratios than laser etching (GI: p<0.001, GII: p<0.01, and GIII: p<0.01). The SEM photomicrographies revealed open (CG) and partially open dentin tubules (GI, GII, and GIII). μ-EDXRF mappings illustrated that acid etching created homogeneous distribution of inorganic content over dentin. Er:YAG laser etching (220 mJ) produced irregular elemental distribution and changed the stoichiometric proportions of hydroxyapatite, as showed by an increase of mineral content. Decreases and increases of mineral content in the μ-EDXRF images are correlated to holes and mounds, respectively, as found in SEM images.

  3. The effects of different nickel-titanium instruments on dentinal microcrack formations during root canal preparation.

    PubMed

    Ustun, Yakup; Aslan, Tugrul; Sagsen, Burak; Kesim, Bertan

    2015-01-01

    The aim of the present study was to investigate the incidence of dentinal microcracks caused by different preparation techniques. 120 extracted human mandibular incisor teeth were divided into five experimental groups and one control group (n = 20): Group 1: Hand preparation with balanced force technique up to #25 K-file. Group 2: Preparation with only ProTaper F2 instrument in a reciprocating movement. Group 3: Preparation with Reciproc R25 instrument in a reciprocating movement. Group 4: Preparation with ProTaper instruments up to F2 instrument. Group 5: Preparation with ProTaper Next instruments up to X2 instrument. No procedure was applied to control group. The roots were sectioned horizontally at 3, 6 and 9 mm from the apex and examined. Absence or presence of dentinal microcracks was noted. The Chi-square test was performed to compare the appearance of cracked roots between all groups. There were no significant differences among the groups (P > 0.05). In conclusion, except the hand file and control group, all experimental groups showed microcrack formations.

  4. Effect of Sonic Vibrations on Bond Strength of Fiberglass Posts Bonded to Root Dentin.

    PubMed

    Mushashe, Amanda Mahammad; Amaral, Rodrigo Otavio Jatahy Ferreira do; Rezende, Carlos Eduardo Edwards; Filho, Flares Baratto; Cunha, Leonardo Fernandes da; Gonzaga, Carla Castiglia

    2017-01-01

    Sonic vibrations may improve the bond strength and durability of fiberglass posts by improving adhesive penetration into dentin as well as the cement flow. The objective of this study was to evaluate the effect of sonic vibrations on the bond strength between fiberglass posts and root dentin using the pull-out test. Bovine roots were endodontically treated and divided randomly into four groups (n=12): Group C - conventional cementation (control); Group SA - sonic vibration (Smart Sonic Device, FGM) of the adhesive system and conventional post accommodation; SP group - conventional adhesive application and sonic vibration of the post during accommodation; and SASP - sonic vibration of the system adhesive and the post during accommodation. The posts were cleaned, treated with a silane and adhesive system (Ambar, FGM), and cemented with a dual-cured resin cement (Allcem Core, FGM). After 24 h, the specimens were subjected to mechanical tests and failure analyses. Representative specimens were analyzed by a scanning electron microscope to observe the cementation line. The results were analyzed using ANOVA and Tukey's test (a=5%). The bond strengths were as follows: SASP (90.9±27.1 N), C (121.4±60.6 N), SA (127.6±31.8 N) and SP (156.4±41.3 N). The use of sonic vibrations during the application of adhesive or post cementation separately did not affect the bond strength but had a negative effect when used for both procedures.

  5. The effects of different nickel-titanium instruments on dentinal microcrack formations during root canal preparation

    PubMed Central

    Ustun, Yakup; Aslan, Tugrul; Sagsen, Burak; Kesim, Bertan

    2015-01-01

    Objective: The aim of the present study was to investigate the incidence of dentinal microcracks caused by different preparation techniques. Materials and Methods: 120 extracted human mandibular incisor teeth were divided into five experimental groups and one control group (n = 20): Group 1: Hand preparation with balanced force technique up to #25 K-file. Group 2: Preparation with only ProTaper F2 instrument in a reciprocating movement. Group 3: Preparation with Reciproc R25 instrument in a reciprocating movement. Group 4: Preparation with ProTaper instruments up to F2 instrument. Group 5: Preparation with ProTaper Next instruments up to X2 instrument. No procedure was applied to control group. The roots were sectioned horizontally at 3, 6 and 9 mm from the apex and examined. Absence or presence of dentinal microcracks was noted. Results: The Chi-square test was performed to compare the appearance of cracked roots between all groups. There were no significant differences among the groups (P > 0.05). Conclusions: In conclusion, except the hand file and control group, all experimental groups showed microcrack formations. PMID:25713483

  6. Prognosis of intentional replantation of vertically fractured roots reconstructed with dentin-bonded resin.

    PubMed

    Hayashi, Mikako; Kinomoto, Yoshifumi; Takeshige, Fumio; Ebisu, Shigeyuki

    2004-03-01

    There is no particular treatment established to preserve vertically fractured teeth. We evaluated the long-term prognosis of the intentional replantation of 26 vertically fractured roots after reconstruction with 4-META/MMA-TBB dentin-bonded resin. Replanted teeth were evaluated according to clinical criteria and radiographic examinations for periods ranging from 4 to 76 months. Eighteen cases were functional and retained, with six fully successful; the others needed further observation. Eight cases failed to respond to treatment because of refracture, recurrence of gingival inflammation, or both. Longevity was calculated as 88.5% at 12 months after replantation, 69.2% at 36 months, and 59.3% at 60 months. All failures occurred in premolar and molar teeth. Longitudinal fractures extending more than 2/3 from the cervical portion toward the apex showed significantly shorter longevity compared with fractures within the 2/3 area (log-rank test, p = 0.02). Intentional replantation of vertically fractured roots reconstructed with dentin-bonded resin may be considered for incisors as an alternative to extraction, although the long-term success is not optimal.

  7. Evaluation of Chlorine Dioxide Irrigation Solution on the Microhardness and Surface Roughness of Root Canal Dentin.

    PubMed

    Ballal, Nidambur Vasudev; Khandewal, Deepika; Karthikeyan, Saravana; Somayaji, Krishnaraj; Foschi, Federico

    2015-12-01

    The aim of this study was to evaluate the effect of chlorine dioxide and various other more common irrigation solutions on the microhardness and surface roughness of root canal dentin. Fifty human maxillary central incisors were sectioned longitudinally and treated for 1 minute with 5 ml of the following aqueous solutions (v/v%): Group 1: 13.8% chlorine dioxide, Group 2: 17% ethylene diamine tetraacetic acid (EDTA). Group 3: 7% maleic acid, Group 4: 2.5% sodium hypochlorite (5 ml/min), Group 5: Saline (control). Specimens were subjected to microhardness and surface roughness testing. Chlorine dioxide and sodium hypochlorite reduced the microhardness more than other test agents. The highest surface roughness was produced with maleic acid. Chlorine dioxide should be used cautiously during chemomechanical preparation of the root canal system in order to prevent untoward damage to the teeth.

  8. Evaluation of Chlorine Dioxide Irrigation Solution on the Microhardness and Surface Roughness of Root Canal Dentin.

    PubMed

    Ballal, Nidambur Vasudev; Khandewal, Deepika; Karthikeyan, Saravana; Somayaji, Krishnaraj; Foschi, Federico

    2015-09-01

    The aim of this study was to evaluate the effect of chlorine dioxide and various other more common irrigation solutions on the microhardness and surface roughness of root canal dentin. Fifty human maxillary central incisors were sectioned longitudinally and treated for 1 minute with 5 ml of the following aqueous solutions (v/v%): Group 1:13.8% chlorine dioxide, Group 2:17% ethylene diamine tetraacetic acid (EDTA). Group 3: 7% maleic acid, Group 4: 2.5% sodium hypochlorite (5ml/min), Group 5: Saline (control). Specimens were subjected to microhardness and surface roughness testing. Chlorine dioxide and sodium hypochlorite reduced the microhardness more than other test agents. The highest surface roughness was produced with maleic acid. Chlorine dioxide should be used cautiously during chemomechanical preparation of the root canal system in order to prevent untoward damage to the teeth.

  9. Anti-erosive potential of amine fluoride, cerium chloride and laser irradiation application on dentine.

    PubMed

    Wegehaupt, Florian J; Sener, Beatrice; Attin, Thomas; Schmidlin, Patrick R

    2011-12-01

    Ninety-six dentine samples were prepared from human premolars and randomly assigned to eight groups (G1-G8). Samples were treated for 30s with the following solutions: placebo (G1/G2), amine fluoride (Elmex fluid; G3/G4), cerium chloride (G5/G6) and combined fluoride/cerium chloride application (G7/G8). Samples of groups G2, G4, G6 and G8 were additionally irradiated with a carbon dioxide laser through the solutions for 30s. Acid resistance was assessed in a six-time 5-min consecutive lactic acid (pH 3.0) erosion model and calcium release was determined by atomic absorption spectroscopy (AAS). Furthermore, six additional samples per group were prepared and subjected to EDS-analysis. In the non-irradiated groups, specimens of G1 (placebo) showed the highest calcium release when compared to the other treatments (G3, G5 and G7). The highest acid resistance was observed for G7. In G3, calcium release was lower than in G5, but higher than in G7. In general (except for the placebo groups), calcium release in the laser-irradiated groups was higher compared with the respective non-irradiated groups. EDS showed a replacement of calcium by cerium and of phosphor by fluoride. The highest anti-erosive potential was found after combined cerium chloride and amine fluoride application. Laser irradiation had not adjunctive effect. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Influence of the dentinal wall on the pH of sodium hypochlorite during root canal irrigation.

    PubMed

    Macedo, Ricardo Gomes; Herrero, Noemi Pascual; Wesselink, Paul; Versluis, Michel; van der Sluis, Luc

    2014-07-01

    The purpose of this study was to evaluate the influence of dentin on the pH levels of different concentrations of sodium hypochlorite (NaOCl) solutions over time and to evaluate if preconditioning of dentin with 17% EDTA or agitation of the NaOCl solution influences these pH levels. A novel clinically representative model that scales with the ratio of the irrigant volume to the dentin surface area of a human root canal was used. Three standardized bovine dentin bars (2 × 2 × 10 mm) were placed in a plastic test tube. A total of 150 tubes were distributed in 29 groups. In the first experiment, the pH of various NaOCl solutions, with different concentrations (3%, 6%, and 9%) and starting pH levels (5 and 12), was monitored during exposure to dentin between 10 and 300 seconds. In a second experiment, the effect of agitation (45 Hz) and pretreatment of dentin with 17% EDTA on the pH levels of various NaOCl solutions was studied after 30 seconds of exposure to dentin. The short-term chemical stability of the tested solutions was assessed for both the concentration and the pH. The exposure time (P < .001) and concentration of the NaOCl solution (P < .011) significantly influence the pH level after exposure to dentin. However, the change in pH is too small to induce a change in the irrigant antimicrobial/tissue dissolution capacity. Agitation of the irrigant and preconditioning of the dentin did not alter the pH (P > .05). Both the pH 5 and pH 12 solutions were chemically stable for 1 hour. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  11. Chronologic comparison of root dentin moisture in extracted human teeth stored in formalin, sodium azide, and distilled water.

    PubMed

    Komabayashi, Takashi; Ahn, Chul; Zhang, Song; Zhu, Qiang; Spångberg, Larz S W

    2009-07-01

    This study quantified in vitro the root dentin moisture when 10% formalin (group A), 3% sodium azide (group B), and distilled water (group C) were used as teeth storage media. The root dentin moisture of 66 extracted human mandibular single-rooted teeth was measured at baseline (day 0) and at 1, 3, 7, and 14 days using a digital grain moisture meter. The baseline dentin moisture value was used as covariate in the generalized estimating equation (GEE) analysis. The mean dentin moisture values (%) +/- SD on days 0, 1, 3, 7, and 14 were, respectively: 10.6 +/- 0.64, 14.3 +/- 0.71, 14.6 +/- 0.84, 14.4 +/- 0.64, and 14.7 +/- 0.75 in group A; 11.4 +/- 0.94, 14.6 +/- 0.95, 14.6 +/- 0.76, 14.6 +/- 0.93, and 14.8 +/- 0.81 in group B; and 10.2 +/- 0.95, 12.8 +/- 0.90, 13.3 +/- 0.95, 13.0 +/- 0.91, and 13.2 +/- 0.89 in group C. The dentin moisture increased in all 3 groups; however, there was no overall significant difference in moisture between the formalin and sodium azide groups.

  12. Dentinal microcrack formation during root canal preparations by different NiTi rotary instruments and the self-adjusting file.

    PubMed

    Yoldas, Oguz; Yilmaz, Sehnaz; Atakan, Gokhan; Kuden, Cihan; Kasan, Zeynep

    2012-02-01

    The purpose of this study was to compare dentinal microcrack formation while using hand files (HFs), 4 brands of nickel-titanium (NiTi) rotary files and the self-adjusting file. One hundred forty mandibular first molars were selected: 20 teeth were left unprepared and served as control, and the remaining 120 teeth were divided into 6 groups. HFs, HERO Shaper (HS; Micro-Mega, Besancon, France), Revo-S (RS, Micro-Mega), Twisted File (TF; SybronEndo, Orange, CA), ProTaper (PT, Dentsply Maillefer), and SAFs were used to prepare the 2 mesial canals. Roots were then sectioned 3, 6, and 9 mm from the apex, and the cut surface was observed under a microscope and checked for the presence of dentinal microcracks. The control, HF, and SAF groups did not show any microcracks. In roots prepared with the HS, RS, TF, and PT, dentinal microcracks were observed in 60%, 25%, 44%, and 30% of teeth, respectively. There was a significant difference between the control/HF/SAF group and the 4 NiTi rotary instrument groups (P < .0001). However, no significant difference was found among the 4 NiTi rotary instruments (P > .005). All rotary files created microcracks in the root dentin, whereas the SAF file and hand instrumentation presented with satisfactory results with no dentinal microcracks. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  13. Effect of surface treatment of fiberglass posts on bond strength to root dentin.

    PubMed

    Valdivia, Andréa Dolores Correia Miranda; Novais, Veridiana Resende; Menezes, Murilo de Sousa; Roscoe, Marina Guimarães; Estrela, Carlos; Soares, Carlos José

    2014-01-01

    This study evaluated the influence of the surface treatments of fiberglass posts on bond strength to root dentin using push-out test. Forty bovine incisor roots were endodontically treated. The surface of the fiberglass posts (Exacto #2, Angelus) were treated using 4 different protocols (n=10): Control - 70% ethanol for 1 min; 37% phosphoric acid for 1 min; 10% hydrofluoric acid for 1 min; and 24% hydrogen peroxide for 1 min. After a silane coupling agent was applied for 1 min and all posts were cemented using self-adhesive resin cement (RelyX Unicem, 3M-ESPE). The roots were sectioned and two 1-mm-thick slices were obtained from each third: cervical, middle and apical. The specimens were subjected to the push-out test with a crosshead speed of 0.5 mm/min. Data were analyzed by repeated measures ANOVA followed by Tukey's HSD tests (=0.05). The surface treatment (p<0.001) and root third region (p=0.007) factors were significant. The retention to root canal was affected by surface treatment type. The post surface treatment with 24% hydrogen peroxide for 1 min yielded significantly higher bond strength when the fiberglass posts were cemented with RelyX Unicem.

  14. Effects of Dentin Moisture on Cementation of Fiber Posts to Root Canals.

    PubMed

    Rezende, Eluise C; Gomes, Giovana Mongruel; Szesz, Anna Luiza; da Silveira Bueno, Carlos Eduardo; Reis, Alessandra; Loguercio, Alessandro D

    2016-01-01

    Achieving optimal moisture inside the root canal is a challenge during bonding of fiberglass posts. This study evaluated the effect of different moisture patterns on the push-out bond strength (PBS) and nanoleakage (NL) of fiber posts bonded to the root canal of two simplified etch-and-rinse adhesives. The roots of 72 human premolars were endodontically prepared and divided into 6 groups according to the combination of the main factors: adhesive (Ambar and Adper Single Bond 2) and moisture (dry, wet, and overwet). The posts were cemented and after 1 week, the roots were cross sectioned into 6 disks. Two disks each were obtained from the cervical, middle, and apical thirds, and the PBS test was carried out (0.5 mm/min; n = 8). The NL was evaluated by scanning electron microscopy after the immersion of specimens in 50% silver nitrate (n = 4). The failure pattern was examined on all debonded specimens. Data were analyzed by three-way repeated measures ANOVA and Tukey's test (5%). For both adhesives, higher PBS values and lower NL were observed in the wet groups, and lower PBS and higher NL in the dry group. In general, the overwet condition showed intermediate results. The root dentin walls should be left slightly moist before performing fiber post cementation procedures.

  15. Effects of light penetration and smear layer removal on adhesion of post-cores to root canal dentin by self-etching adhesives.

    PubMed

    Wu, Hongxia; Hayashi, Mikako; Okamura, Kenji; Koytchev, Evgeni V; Imazato, Satoshi; Tanaka, Saori; Tanaka, Yuko; Sano, Hidehiko; Ebisu, Shigeyuki

    2009-12-01

    This study investigated the effects of light penetration and removal of smear layer on the adhesive properties of self-etching adhesives to root canal dentin when using fiber posts. Altogether 54 human incisors and premolars were decoronated, and the roots after preparing the post space were randomly assigned into six groups. Three groups were treated with a light-cured self-etching adhesive and the other three with a dual-cured self-etching adhesive. In a further sub-division, the first group was light-cured with an irradiation unit; the second was light-cured with the irradiation unit and a light-guiding attachment; and the third was light-cured with the irradiation unit and the attachment after removing smear layer by EDTA and NaOCl. Then, a glass-fiber post was luted into the post space by a dual-cured composite. After 24h, an hourglass-shaped specimen was trimmed and subjected to MTBS testing. Using the light-guiding attachment and removing the smear layer reduced the incidence of pre-testing failure significantly from 57.1% to 19.0% (p<0.05) in the light-cured adhesive groups and from 68.3% to 3.2% (p<0.01) in the dual-cured adhesive groups. The MTBS in different locations within a post space were in the range from 8.9 to 17.5MPa in the light-cured group and from 11.2 to 17.2MPa in the dual-cured group. Better light penetration in post spaces and removal of the smear layer are effective in improving the adhesive properties of self-etching adhesives to root canal dentin when using fiber posts.

  16. Bond strength of composite to dentin: effect of acid etching and laser irradiation through an uncured self-etch adhesive system

    NASA Astrophysics Data System (ADS)

    Castro, F. L. A.; Carvalho, J. G.; Andrade, M. F.; Saad, J. R. C.; Hebling, J.; Lizarelli, R. F. Z.

    2014-08-01

    This study evaluated the effect on micro-tensile bond strength (µ-TBS) of laser irradiation of etched/unetched dentin through an uncured self-etching adhesive. Dentinal surfaces were treated with Clearfil SE Bond Adhesive (CSE) either according to the manufacturer’s instructions (CSE) or without applying the primer (CSE/NP). The dentin was irradiated through the uncured adhesive, using an Nd:YAG laser at 0.75 or 1 W power settings. The adhesive was cured, composite crowns were built up, and the teeth were sectioned into beams (0.49 mm2) to be stressed under tension. Data were analyzed using one-way ANOVA and Tukey statistics (α = 5%). Dentin of the fractured specimens and the interfaces of untested beams were observed under scanning electron microscopy (SEM). The results showed that non-etched irradiated surfaces presented higher µ-TBS than etched and irradiated surfaces (p < 0.05). Laser irradiation alone did not lead to differences in µ-TBS (p > 0.05). SEM showed solidification globules on the surfaces of the specimens. The interfaces were similar on irradiated and non-irradiated surfaces. Laser irradiation of dentin through the uncured adhesive did not lead to higher µ-TBS when compared to the suggested manufacturer’s technique. However, this treatment brought benefits when performed on unetched dentin, since bond strengths were higher when compared to etched dentin.

  17. Conditioning of root canals prior to dowel cementation with composite luting cement and two dentine adhesive systems.

    PubMed

    Liberman, R; Ben-Amar, A; Urstein, M; Gontar, G; Fitzig, S

    1989-11-01

    Two hundred and forty root canals of extracted single-rooted teeth were prepared to the same dimension, and Dentatus posts of equal size were cemented without screwing them into the dentine. Five cleansing solutions and two dentine adhesive systems were evaluated prior to post-cementation using chemical-cure composite resin. 'Pull-out' tests were then conducted in order to evaluate the bond strength of these intra-pulpal posts. The use of Conclude (composite luting cement) alone, with or without the cleansing solutions, resulted in significantly lower pull-out forces. Scotchbond Dental Adhesive gave significantly better results, regardless of the cleansing solution used. Gluma Dentine Adhesive significantly increased the pull-out forces only when used with its supplied cleanser or Tubulicid.

  18. Dentin bond strength of an adhesive system irradiated with an Nd:YAG laser

    NASA Astrophysics Data System (ADS)

    Ruschel, V. C.; Malta, D. A. M. P.; Monteiro, S., Jr.

    2016-11-01

    The objective of this study was to evaluate the microtensile bond strength of an adhesive system applied to dentin, followed by Nd:YAG laser irradiation. Twenty-two recently extracted third molars were divided into four groups (n  =  5). In the G1 and G2 groups, the adhesive system was applied conventionally, and in groups G3 and G4, the adhesive system was irradiated with an Nd:YAG laser (100 J cm-2). The specimens were stored in distilled water at 37 °C, those in groups G1 and G3 for 24 h, and those in groups G2 and G4 for 3 months. Two teeth from groups G1 and G3 were used for observation of the hybrid layer, using a confocal microscope (n  =  1). The teeth were submitted to a microtensile bond strength test. Analysis of the type of fracture was performed using a stereoscope (40×). The results for microtensile bond strength (MPa) and standard deviation (±SD) were: G1—31.68 (5.14); G2—37.88 (±5.04) G3—35.32 (±8.79) G4—31.53 (±9.01). There were no significant differences among the groups (p  >  0.05). Adhesive failure was predominant in all the groups. The Nd:YAG laser irradiation of the adhesives did not influence dentin bond strength during the periods of 24 h or 3 months of storage in distilled water.

  19. Mechanical properties and bond strength of dual-cure resin composites to root canal dentin.

    PubMed

    Aksornmuang, Juthatip; Nakajima, Masatoshi; Foxton, Richard M; Tagami, Junji

    2007-02-01

    To evaluate the regional mechanical properties of dual-cure resin composites and their regional bond strengths to root canal dentin. One of the following dual-cure resin composites was placed in artificial post spaces: Unifil Core (UC), Clearfil DC Core (DC), Build-It FR (BI), Clearfil DC Core-automix (DCA), and photo-cured for 60s. After 24h storage, each specimen was serially sliced to harvest eight hour-glass shaped specimens for measurement of regional ultimate tensile strength (UTS), and the remaining eight semi-circular slabs were polished for the measurement of Knoop Hardness Number (KHN). For the microtensile bond strength (muTBS) test, post cavities were prepared in human premolar roots, and the cavity surfaces treated with Clearfil SE Bond and photo-cured for 10s. The post spaces were then filled with one of the above resin composites and photo-cured for 60s. After 24h storage, each specimen was serially sliced into 8, 0.6x0.6 mm-thick beams for the muTBS test. The data were divided into coronal and apical regions and analyzed using ANOVA and post hoc test (alpha=0.05). UTS and KHN were affected by the type of dual-cure resin composite and region (p<0.0001). There was no relationship between UTS and KHN for each material. The auto-mix type of resin composite possessed superior UTS to that of the hand-mix type. muTBS among the four composite materials were not significantly different at both apical and coronal regions (p>0.05). Regional differences in bond strengths were found for all materials (p<0.05). The UTS and KHN of the dual-cure resin composites varied among each material, however, differences in the mechanical properties of the resin core materials did not affect their adhesion to root canal dentin.

  20. Stability of antibacterial activity of Chlorhexidine and Doxycycline in bovine root dentine

    PubMed Central

    Khademi, Abbas Ali; Saleh, Marjan; Khabiri, Masoud; Jahadi, Sanaz

    2014-01-01

    Objective: The aim of this study was to compare the substantivity of chlorhexidine (CHX) and doxycycline bond to the dentin in diffusion disk method. Methods: A total of 92 dentin disks were prepared from Bovine's teeth root. After removing cementum and standardizing disks in weight and outer diameter, they were irrigated with sodium hypochlorite 2.5%, ethylenediaminetetraacetic acid 17% and sterile saline and sterilled in autoclave. Then, the first group (n = 36) were irrigated with chlrohexine 2% and the second group (n = 36) with doxycycline 100 mg/mL, each for a period of 10 min. The third group (n = 20) was considered as the control group. Samples were divided into four subgroups, which after 1 day, 3, 6, and 12 weeks were incubated in plates containing Muller Hinton agar broth and Enterococcus faecalis for a period of 48 h at 37°C temperature; then the diameter of the zone of inhibition was measured. The antimicrobial effect of irrigating solutions without binding to the dentin was also studied using the plate well method. One-way and univariate variance tests as well as Post-hoc Tukey were used for data analyses. Findings: The diameter of the zone of inhibition of doxycycline group was significantly more than the CHX group from the beginning to the 3rd week (P < 0.005). After 3rd week, mean diameter in doxycycline group declined as compared with the CHX group up to 12th week (P < 0.005). The difference between means in two groups was not significant in the 3rd week (P = 0.87). Conclusion: The results of this study show that CHX and doxycycline show antibacterial activity for 12 weeks; although after 3rd week, the substantivity of CHX was significantly greater than doxycycline. Both of these irrigants can be used in other pharmacological and medical fields whenever a long-lasting antibacterial action is needed. PMID:24991631

  1. Regional bond strengths to root canal dentin of fiber posts luted with three cementation systems.

    PubMed

    Gomes, Giovana Mongruel; Gomes, Osnara Maria Mongruel; Reis, Alessandra; Gomes, João Carlos; Loguercio, Alessandro Dourado; Calixto, Abraham Lincoln

    2011-01-01

    This study evaluated the influence of the cementation system on the regional push-out bond strength and failure pattern of fiber posts to radicular dentin. The roots of 48 extracted human incisors were prepared and divided into 3 groups (n = 16), according to the cementation system: AdperScotchbond Multi-Purpose + resin cement RelyX ARC (SBMP+ARC); Adper SingleBond 2 + RelyX ARC (SB+ARC) and; RelyX U100 self-adhesive resin cement (U100). The posts were cemented as per manufacturer's instructions for each cementation system. After 1 week, the roots were sectioned transversely into 6 discs. Two discs were obtained from the cervical, middle and apical thirds and the push-out test was carried out. The failure pattern was examined on all debonded specimens. The data were analyzed by two-way repeated measures ANOVA and Tukey's test. When U100 was used, no statistically significant difference (p>0.05) was observed among the different root regions. Statistically higher push-out bond strength values were detected in the cervical third for SBMP+ARC and SB+ARC (p<0.05). The U100 showed significantly more mixed failures than SBMP+ARC in the apical third (p<0.05). In conclusion, the self-adhesive cement RelyX U100 was the only cement not sensitive to the root canal region.

  2. Pulp-dentine complex changes and root resorption during intrusive orthodontic tooth movement in patients prescribed nabumetone.

    PubMed

    Villa, Paula A; Oberti, Giovanni; Moncada, Cesar A; Vasseur, Olga; Jaramillo, Alejandro; Tobón, Diego; Agudelo, Jaime A

    2005-01-01

    Pulpitis, external root resorption, and pain may be experienced during orthodontic movement. The use of nonsteroidal anti-inflammatory drugs (NSAIDs) has been suggested to control these changes. The purpose of this study was to observe pulp-dentinal reactions, root resorption, tooth pain, and tooth movement after the application of a 4-ounce intrusive orthodontic force to human maxillary first premolars in patients given the NSAID nabumetone. Thirty-four maxillary first premolars were evaluated. A placebo was prescribed to 17 patients after an intrusive force was activated and reactivated for an 8-week period on the right side. The same procedure was repeated on the left side after patients were given nabumetone. Pulp-dentinal reactions and external root resorption were evaluated by histology. Pain and movement were also evaluated. Nabumetone was found to be useful in reducing pulpitis, external root resorption, and pain caused by intrusive orthodontic movement, without altering tooth movement in response to the application of orthodontic force.

  3. The effect of a desensitizer and CO2 laser irradiation on bond performance between eroded dentin and resin composite

    PubMed Central

    Ding, Meng; Shin, Sang-Wan; Kim, Min-Soo

    2014-01-01

    PURPOSE This study was aimed to evaluate effect of the desensitizing pretreatments on the micro-tensile bond strengths (µTBS) to eroded dentin and sound dentin. MATERIALS AND METHODS Forty-two extracted molars were prepared to form a flat dentin surface, and then they were divided into two groups. Group I was stored in distilled water while group II was subjected to a pH cycling. Each group was then subdivided into three subgroups according to desensitizing pretreatment used: a) pretreatment with desensitizer (Gluma); b) pretreatment with CO2 Laser (Ultra Dream Pluse); c) without any pretreatment. All prepared surfaces were bonded with Single Bond 2 and built up with resin composite (Filtek Z250). The micro-tensile bond test was performed. Fracture modes were evaluated by stereomicroscopy. Pretreated surfaces and bonded interfaces were characterized by scanning electron microscope (SEM). The data obtained was analyzed by two-way ANOVA (α=0.05). RESULTS For both sound and eroded dentin, samples treated with desensitizer showed the greatest µTBS, followed by samples without any treatment. And samples treated with CO2 laser showed the lowest µTBS. SEM study indicated that teeth with eroded dentin appeared prone to debonding, as demonstrated by existence of large gaps between adhesive layers and dentin. CONCLUSION Pretreatment with Gluma increased the µTBS of Single Bond 2 for eroded and sound teeth. CO2 laser irradiation weakened bond performance for sound teeth but had no effect on eroded teeth. PMID:25006379

  4. Cariostatic effect of fluoride-containing restorative materials associated with fluoride gels on root dentin

    PubMed Central

    BORGES, Fernanda Tavares; CAMPOS, Wagner Reis da Costa; MUNARI, Lais Sant'ana; MOREIRA, Allyson Nogueira; PAIVA, Saul Martins; MAGALHÃES, Claudia Silami

    2010-01-01

    Secondary caries is still the main cause of restoration replacement, especially on the root surface Objective This in vitro study evaluated the cariostatic effects of fluoride-containing restorative materials associated with fluoride gels, on root dentin. Materials and Methods A randomized complete block design was used to test the effects of the restorative systems, fluoride regimes and the interactions among them at different distances from restoration margins. Standardized cavities were prepared on 240 bovine root specimens and randomly assigned to 15 groups of treatments (n=16). Cavities were filled with the following restorative materials: Ketac-Fil (3M-ESPE); Vitremer (3M-ESPE); Dyract/Prime & Bond NT (Dentsply); Charisma/Gluma One Bond (Heraeus Kulzer) and the control, Z250/Single Bond (3M-ESPE). The specimens were subjected to a pH-cycling model designed to simulate highcaries activity. During the cycles, 1.23% acidulated phosphate fluoride, 2.0% neutral sodium fluoride or deionized/distilled water (control) was applied to the specimens for 4 min. The surface Knoop microhardness test was performed before (KHNi) and after (KHNf) the pH cycles at 100, 200 and 300 mm from the margins. Dentin microhardness loss was represented by the difference in initial and final values (KHNi - KHNf). Data were analyzed by Friedman's and Wilcoxon's tests, ANOVA and Tukey's test (α=5%). Results The interaction of restorative systems and topical treatments was not significant (p=0.102). Dentin microhardness loss was lowest closer to the restoration. Ketac-fil presented the highest cariostatic effect. Vitremer presented a moderate effect, while Dyract and Charisma did not differ from the control, Z250. The effects of neutral and acidulated fluoride gels were similar to each other and higher than the control. Conclusion Conventional and resin-modified glass ionomer cements as well as neutral and acidulated fluoride gels inhibit the progression of artificial caries adjacent to

  5. Effects of Er:YAG laser irradiation and manipulation treatments on dentin components, part 1: Fourier transform-Raman study

    NASA Astrophysics Data System (ADS)

    Soares, Luís Eduardo Silva; Do Espírito Santo, Ana Maria; Junior, Aldo Brugnera; Zanin, Fátima Antônia Aparecida; da Silva Carvalho, Carolina; de Oliveira, Rodrigo; Martin, Airton Abraha~O.

    2009-03-01

    The effects of laser etching, decontamination, and storage treatments on dentin components were studied using Fourier transform (FT)-Raman spectroscopy. Thirty bovine incisors were prepared to expose the dentin surface and then divided in two main groups based upon the decontamination process and storage procedure: autoclaved (group A, n=15) or stored in thymol aqueous solution (group B, n=15). The surfaces of the dentin slices were schematically divided into four areas, with each one corresponding to a treatment subgroup. The specimens were either etched with phosphoric acid (control subgroup) or irradiated with erbium-doped yttrium-aluminum-garnet (Er:YAG) laser (subgroups: I-80 mJ, II-120 mJ, and III-180 mJ, and total energy of 12 J). Samples were analyzed by FT-Raman spectroscopy; we collected three spectra for each area (before and after treatment). The integrated areas of five Raman peaks were calculated to yield average spectra. The areas of the peaks associated with phosphate content (P<0.001), type I collagen, and organic C-H bonds (P<0.05) were reduced significantly in group A (control). Analyses of samples irradiated with reduced laser energies did not show significant changes in the dentin components. These results suggest that thymol storage treatment is advised for in vitro study; furthermore, 12 J of Er:YAG laser energy does not affect dentin components.

  6. [Raman spectroscopic analysis of post-cement-root canal dentin interface].

    PubMed

    Li, Zhen-Chun; Wu, Xuan; Chen, Xiao-Dong; Ma, Hong-Mei; Hao, Feng-Yu

    2007-06-01

    To examine the compositions of those adhesion modes between luting cements and canal dentin, and to evaluate the dentin-cement-post interface by Laser-Ranian spectroscopy. Three representative luting cements (zinc phosphate, glass ionomer and resin cements), two kinds of prefabricated posts (titanium and fiber-glass), six extracted intact human maxillary anterior teeth were used canal dentin after endodontic treatment. Laser-Raman spectroscopy measure of cement, post and canal dentin before and after luting together. There are no evident Raman spectra change cross the ZPC/dentin interface and glass ionomer/dentin interface, while cross the resin/dentin interface and resin/glass fiber post interface can be seen special Raman spectra. Laser-Raman microspectroscopy is a useful analytical technique for evaluation interface between dentin and luting cements. Resin cement may interact with dentin and glass fiber post.

  7. Effect of Dentin Moisture and Application Mode of Universal Adhesives on the Adhesion of Glass Fiber Posts to Root Canal.

    PubMed

    Gruber, Yançanã Luizy; Bakaus, Thaís Emanuelle; Gomes, Osnara Maria Mongruel; Reis, Alessandra; Gomes, Giovana Mongruel

    2017-09-21

    To evaluate the effect of dentin moisture and application mode of universal adhesives on bond strength (BS) and nanoleakage (NL) of fiber posts bonded to root dentin. The roots of 96 extracted human canines were treated endodontically, and the fiber posts were cemented according to the combination of the following factors: dentin moisture (dry and wet), cementation system [Single Bond Universal/RelyX ARC (SBU) and Prime&Bond elect/Enforce (PBE)], and adhesive application [active (A) and passive (P)] in accordance with the manufacturer's instructions. After one week, the specimens were transversely sectioned into six 1-mm-thick disks. From each group, 8 specimens were subjected to the pushout BS test and the other 4 specimens underwent NL analysis. For both tests, the data were subjected to 3-way repeated measures ANOVA and Tukey's tests (α = 0.05). For BS and NL, the cross-product interaction of all factors was significant (p < 0.05). Lower BS was observed under P application independent of the dentin moisture; for A application, SBU showed higher BS than did PBE in both moisture conditions. Nanoleakage was present in all groups and ranged from 22.9% to 36%. The active application of universal adhesives improves the adhesion in fiber post cementation, independent of dentin moisture condition.

  8. Antimicrobial activity and substantivity of Uncaria tomentosa in infected root canal dentin.

    PubMed

    Herrera, Daniel Rodrigo; Durand-Ramirez, Jorge Enrique; Falcão, Amanda; Silva, Emmanuel João Leal Nogueira da; Santos, Elizabete Brasil Dos; Gomes, Brenda Paula Figueiredo de Almeida

    2016-01-01

    The aim of this study was to analyze the antimicrobial activity and substantivity of Uncaria tomentosa Willd DC (cat's claw, CC) in root dentin contaminated with Enterococcus faecalis. Forty-eight human premolars were contaminated with E. faecalis (ATCC 29212) and randomly divided into four groups according to the irrigant used during chemomechanical preparation (CMP): CC group: 2% CC gel; CHX group: 2% chlorhexidine digluconate gel (CHX); NaOCl group: 5.25% sodium hypochlorite (NaOCl); and SS group: sterile saline (SS). Microbiological samples were collected before (S1) and after (S2) CMP and after 7 days (S3). Colony-forming units (CFU/mL) at the different sampling times and comparisons among the groups were statistically analyzed by Wilcoxon and Kruskal-Wallis tests (p < 0.05). Significant bacterial reduction was achieved in all groups after CMP (p < 0.05). Results show no significant difference between S3 and S2 (p > 0.05) in the CC and CHX groups. Bacterial load was higher in S3 than in S2 samples (p < 0.05) in the NaOCl and SS groups. Our results suggest antibacterial effect of 2% CC gel against E. faecalis in infected dentin, in addition to antibacterial substantivity of 2% CC and 2% CHX up to 7 days.

  9. Dentin hypersensitivity clinical study comparing LILT and LEDT keeping the same irradiation parameters

    NASA Astrophysics Data System (ADS)

    Lizarelli, R. F. Z.; Miguel, F. A. C.; Freitas-Pontes, K. M.; Villa, G. E. P.; Nunez, S. C.; Bagnato, V. S.

    2010-11-01

    Dentin hypersensitivity is a common condition associated with high dental pain. A new LED-based (light emitting diode) light source has been used as an experimental tool in some studies. Purpose: The main objective was to compare these two light sources emitting in the same spectral band (red - from 625 to 660 nm) to promote pain relief. Material and methods: A total of 6 sessions were accomplished, being three irradiation sessions and three follow-up sessions. This single-blind study compared a control group (Placebo) and two other groups with different equipments: low laser intensity treatment (LILT) and a light emitting diode system treatment (LEDT). Results: The results showed that there is no statistical difference between LILT and LEDT groups, however, both were better than control group (p <= 0.01) in terms of treatment efficiency; there is no difference between the second and the third sessions for both treatment, it means that the third session was not necessary; finally, the improvement at the end of the entire research (follow up care of 30 days) was very expressive in comparison to pre-treatment situation for all teeth (p <= 0.01). Conclusion: LILT and LEDT were equally effective to treat dentine hypersensitivity, a 3rd treatment session was not necessary/two sessions are enough.

  10. SEM evaluation of root canal dentin morphology after Ni-Ti instrumentation.

    PubMed

    Pirani, Chiara; Feletti, Giovanni; Cretti, Roberto; Acquaviva, Giovanni Luca; Marchionni, Silvia; Prati, Carlo

    2009-01-01

    The aim of this study was to compare, through scanning electron microscope (SEM), the ability of four Ni-Ti rotary instrument systems in shaping root canal walls and their ability in removing smear layer and dentin debris. Forty-six extracted single-rooted human teeth were divided into four groups and prepared to size 35 (Alpha System, FlexMaster, MFile) or 30 (NRT files). Irrigation was carried out with NaOCl and EDTA. Three parameters were evaluated in the coronal, middle, and apical thirds of the root canals: smear layer morphology, pulpal-inorganic debris presence and surface profile morphology. Data were statistically analyzed using the Kruskal-Wallis test (ANOVA). None of the Ni-Ti rotary instrument systems resulted in being able to obtain constantly regular shaped surfaces in apical thirds, where smear layer, pulpal and inorganic debris were often present. NRT file specimens resulted in being relatively free from debris and smear layer and gained better results and scores at any canal level.

  11. Evaluation of dentinal defect formation after root canal preparation with two reciprocating systems and hand instruments: an in vitro study.

    PubMed

    Helvacioglu-Yigit, Dilek; Aydemir, Seda; Yilmaz, Ayca

    2015-03-04

    The purpose of this study was to evaluate the presence of dentinal defects after root canal preparation with hand instruments and two different reciprocating instruments. Sixty freshly extracted mandibular incisor teeth were selected for this in vitro study. On the basis of root length, mesiodistal and buccolingual dimensions, the teeth were allocated into three identical experimental groups (n = 15) and one control group (n = 15). The teeth in the control group were left unprepared. The other groups were: stainless steel hand instruments, WaveOne® Primary instruments and RECIPROC® R25 instruments. The reciprocating instruments were used with a reciprocating gentle in-and-out motion in a torque-limited electric motor at the appropriate preset mode. Horizontal sections were made 3, 6 and 9 mm from the apex. Samples were stained with methylene blue and viewed through a stereomicroscope. The presence of dentinal defects (fractures, incomplete cracks and craze lines) and their locations were investigated by two endodontists. These data were analysed statistically by Fisher's exact and chi-square tests. No defects were observed in the unprepared group. All instruments caused dentinal defects, with no significant differences between the instrument systems. All experimental groups demonstrated significantly more defects at the 3-mm level in comparison with the unprepared group (p = 0.032). At the other levels, there was no significant difference between the experimental groups and the control group. The use of hand or reciprocating instruments could induce the formation of dentinal defects during root canal preparation.

  12. Evaluation of dentinal defect formation after root canal preparation with two reciprocating systems and hand instruments: an in vitro study

    PubMed Central

    Helvacioglu-Yigit, Dilek; Aydemir, Seda; Yilmaz, Ayca

    2015-01-01

    The purpose of this study was to evaluate the presence of dentinal defects after root canal preparation with hand instruments and two different reciprocating instruments. Sixty freshly extracted mandibular incisor teeth were selected for this in vitro study. On the basis of root length, mesiodistal and buccolingual dimensions, the teeth were allocated into three identical experimental groups (n = 15) and one control group (n = 15). The teeth in the control group were left unprepared. The other groups were: stainless steel hand instruments, WaveOne® Primary instruments and RECIPROC® R25 instruments. The reciprocating instruments were used with a reciprocating gentle in-and-out motion in a torque-limited electric motor at the appropriate preset mode. Horizontal sections were made 3, 6 and 9 mm from the apex. Samples were stained with methylene blue and viewed through a stereomicroscope. The presence of dentinal defects (fractures, incomplete cracks and craze lines) and their locations were investigated by two endodontists. These data were analysed statistically by Fisher's exact and chi-square tests. No defects were observed in the unprepared group. All instruments caused dentinal defects, with no significant differences between the instrument systems. All experimental groups demonstrated significantly more defects at the 3-mm level in comparison with the unprepared group (p = 0.032). At the other levels, there was no significant difference between the experimental groups and the control group. The use of hand or reciprocating instruments could induce the formation of dentinal defects during root canal preparation. PMID:26019654

  13. Influence of dentin thickness on intrapulpal temperature under simulated pulpal pressure during Nd:YAG laser irradiation.

    PubMed

    Santis, L R; Silva, T M; Haddad, B A; Gonçalves, L L; Gonçalves, S E P

    2017-01-01

    The aim of this study was to evaluate the effects of dentin thickness and pulpal pressure simulation (PPS) on the variation of intrapulpal temperature (∆T) when submitted to an adhesive technique using laser irradiation. Sixty sound human molars were sectioned and randomly divided into two groups (n = 30): group 1-1 mm of dentin thickness; group 2-2 mm of dentin thickness. Each group was divided into two subgroups (n = 15): subgroup A-absence of PPS; subgroup P-presence of PPS (15 cm H2O), sequentially treated with the following: 37 % phosphoric acid, adhesive system (Adper Single Bond), irradiation with Nd:YAG laser (1064 nm, 10 Hz, 60 s) using 60, 80, and 100 mJ/pulse energy parameters and light-curing (10 s). The ∆T was evaluated during the laser irradiation with a digital thermometer. Data were analyzed by three-way ANOVA and Tukey tests (p < 0.05). Three-way ANOVA revealed no significant differences for dentin thickness (p = 0.6512) on ∆T. PPS significantly reduced ∆T (p = 0.0001). The laser energy parameters (p = 0.0027) indicated that 100 mJ presented with significantly greater ∆T when compared to the groups irradiated with 80 and 60 mJ. Dentin thickness did not affect ∆T. The presence of PPS reduced the mean temperature values. The Nd:YAG laser energy parameters had a negative influence on the variation of temperature in the absence of PPS. In the presence of PPS, there was no risk to the pulp, since this study obtained temperature increases below 5.5 °C for all energy parameters, showing the technical viability for in vivo conditions.

  14. Effect of irradiation mode and filling technique on resin/dentin bonding strength in Class I cavities.

    PubMed

    dos Santos, Alex José Souza; Giannini, Marcelo; Paulillo, Luis Alexandre Maffei Sartini; Lovadino, José Roberto; de Carvalho, Ricardo Marins

    2004-01-01

    Factors such as light-curing mode, filling technique and cavity configuration may affect the bonding strength to dentin. This study evaluated the effect of irradiation mode and filling technique on resin/dentin bonding strength on the buccal wall of Class I cavities in human teeth. Occlusal enamel was removed to expose a flat dentin surface. Occlusal cavities (4 x 3 x 3 mm) were prepared in dentin. The adhesive Single Bond was applied according to the manufacturer's instructions and TPH Spectrum composite resin was placed using the following: oblique incremental, horizontal incremental or bulk filling techniques. The composite resin was light-cured either by continuous (600 mW/cm2 for 40 s) or Soft-Start (250 mW/cm2 for 10 s + 600 mW/cm2 for 30 s) modes. Specimens of the control group were obtained by bonding the material to the flat exposed buccal wall of the cavity (C-factor = 1). The teeth were stored in water at 37 degrees C for 24 h and prepared for microtensile testing. Bonded beams of approximately 0.8 mm2 were obtained from the buccal wall and tested with a tension of 0.5 mm/min. Results were analyzed by two-way ANOVA, Tukey's test and Dunnett's test (alpha = 0.05). Incremental placement techniques with both irradiation modes produced higher bonding strength values than the bulk technique (p < 0.05). Bonding strength tested in the cavities had lower values than those obtained in flat dentin surfaces (control group) (p < 0.05), except for incremental fillings using stepped irradiation. Bonding strength to the cavity walls depends on the filling technique and on the irradiation mode of composite resins.

  15. Demineralization effect of EDTA, EGTA, CDTA and citric acid on root dentin: a comparative study.

    PubMed

    Sousa, Simone Maria Galvão de; Silva, Thelma Lopes

    2005-01-01

    The purpose of this study was to biochemically compare the decalcifying effects of 1% EDTA (pH 7.4), 1% EGTA (pH 7.4), 1% CDTA (pH 7.4), 1% citric acid solutions (pH 1.0 and 7.4) and saline solution (control) on root dentin. Forty-eight single-rooted teeth were used in this study. The canals were instrumented by the step-back technique and the roots were randomly divided into six equal experimental groups (n = 8) according to the irrigating agent tested. A total of 30 microL of each solution was pipetted into the root canal and allowed to set undisturbed for 5 minutes. After this time, 15 microL of the solutions were removed from each canal using a Hamilton syringe and placed in a container with 5 mL of deionised water. The microg/mL concentration of calcium ion (Ca2+) extracted from the root canal samples was determined using inductively coupled plasma-atomic emission spectrometry (ICP-AES). Data were analysed by means of the Kruskal-Wallis and Mood's median tests. Citric acid solution at pH 1.0 removed more calcium than at pH 7.4 and than the other chelating solutions tested (p < 0.05). No differences were observed between EDTA and EGTA. Both EDTA and EGTA removed significantly more calcium than CDTA and citric acid at pH 7.4 (p < 0.05). There were no differences between citric acid at pH 7.4 and saline solution, which had the least efficacy for Ca2+ extraction (p > 0.05). These results indicate that citric acid at pH 1.0 is a good alternative as an irrigating solution to remove the smear layer and facilitate the biomechanical procedures.

  16. [Morphologic evaluation of the bonding between adhesive/composite resin and dentin irradiated with Er:YAG and Nd:YAG lasers: comparative study using scanning microscopy].

    PubMed

    Oda, M; Oliveira, D C; Liberti, E A

    2001-01-01

    Since bonding systems were introduced in the restorative procedures carried out with esthetic materials, the treatment of dentin surfaces has been widely studied in order to establish the ideal technique. The application of 37% phosphoric acid on dentin is still the best known method. However, alternative methods for treating the dentin surface have been discussed in the literature, including the utilization of some kinds of laser irradiation. The purpose of this research was to morphologically evaluate the bond between adhesive materials and the dentin treated with Er:YAG and Nd:YAG lasers, in a comparative study by means of scanning electron microscopy (SEM). Irradiation either substituted acid etching, or was associated to it. Recently extracted bovine incisors were utilized. They received class V cavity preparations and were restored with a bonding system and a light-cured composite resin. Meanwhile, some of the teeth underwent irradiation with Er:YAG laser or Nd:YAG laser before the application of the bonding agent and the composite resin. The samples were selected, prepared for SEM and submitted to morphological analysis. Data were registered in photomicrographs. Based on the microscopic observations, we concluded that only in the dentin surfaces submitted to irradiation with Er:YAG laser and to acid conditioning there was penetration of resin into the dentine. With the Nd:YAG laser treatment, there was only visual superposition of resin over the dentin surface, which suggests that there was only occlusion of the tubules, with characteristics of fusion in the superficial dentine.

  17. Effect of calcium hydroxide and endodontic irrigants on fibre post bond strength to root canal dentine.

    PubMed

    Renovato, S R; Santana, F R; Ferreira, J M; Souza, J B; Soares, C J; Estrela, C

    2013-08-01

    To analyse the effect of calcium hydroxide paste, endodontic irrigants and time of application on the bond strength of fibre posts to root canal dentine. Seventy bovine incisors were divided into 7 groups according to removal of calcium hydroxide and distilled water (CHW) (immediate - I; 21 days - 21 days; 6 months - 6 months) and endodontic irrigant (1% sodium hypochlorite - SH; 1% sodium hypochlorite + 17% EDTA - SHE). Fibre posts were cemented (RelyX U100), after which the roots were serially sectioned and submitted to a micro-push-out test. Data were analysed using two-way anova followed by the Tukey's and the Dunnett's tests (α = 0.05). The CHW groups were not significantly different from the control group in 13 of the 18 associated factors (P > 0.05). There were significant reductions in bond strength in the cervical (P = 0.0216) and middle (P = 0.0017) thirds of the root at 6 months in groups irrigated with SH. Irrigation with SHE reduced the bond strength significantly in the middle (P = 0.0488) and apical (P = 0.0252) thirds of the roots in the immediate groups and in the middle third (P = 0.0287) in the 21-day group. Bond strength was greater in the cervical than in the apical thirds of all immediate and 21-day groups (P < 0.05). Bond strength of groups that received CH paste was similar to that found in the control group in 13 of the 18 associated factors. EDTA and SH reduced bond strength in specimens in the immediate (middle and apical thirds) and 21-day (middle third) groups. There was a significant reduction in bond strength in the groups irrigated with SH and tested at 6 months (cervical and middle thirds). There was a predominance of adhesive failures between resin cement and dentine in all groups. © 2012 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  18. Effect of gutta-percha solvents at different temperatures on the calcium, phosphorus and magnesium levels of human root dentin.

    PubMed

    Doğan, H; Taşman, F; Cehreli, Z C

    2001-08-01

    The aim of this study in vitro investigation was to evaluate the alterations caused by warmed gutta-percha solvents on the calcium, phosphorus and magnesium levels of root dentin. Extracted human anterior teeth, whose crowns and apical root thirds had been removed were used as root dentin specimens. The roots were sectioned longitudinally into two segments, cleaned and dried. Segments were divided into 12 groups (n=12). In 6 groups, the specimens received treatment with the following solvents at room temperature (22 degrees C): Chloroform, xylene, eucalyptol, orange oil, halothane and saline (control). Within each group, the specimens were further subgrouped into two to be incubated (100% humidity at 37 degrees C) for 5 and 10 min, respectively, following treatment with the solvents. The remaining six groups were treated with the same solvents which had been previously warmed to body temperature (37 degrees C) and received the same experimental procedures. The levels of calcium, phosphorus and magnesium in each specimen were analysed using energy dispersive spectrometric microanalysis. Statistical analysis of the readings showed that neither warming of the solvents nor prolonged incubation (treatment) time was capable of altering the histochemical composition of cut root dentin surfaces.

  19. Shear bond strength of Biodentine, ProRoot MTA, glass ionomer cement and composite resin on human dentine ex vivo.

    PubMed

    Kaup, Markus; Dammann, Christoph Heinrich; Schäfer, Edgar; Dammaschke, Till

    2015-04-19

    The aim of this study was to compare the shear bond strength of Biodentine, ProRoot MTA (MTA), glass ionomer cement (GIC) and composite resin (CR) on dentine. 120 extracted human third molars were embedded in cold-cured-resin and grinned down to the dentine. For each material 30 specimens were produced in standardised height and width and the materials were applied according to manufacturers´ instructions on the dentine samples. Only in the CR group a self-etching dentine-adhesive was used. In all other groups the dentine was not pre-treated. All specimens were stored at 37.5 °C and 100% humidity for 2d, 7d and 14d. With a testing device the shear bond strength was determined (separation of the specimens from the dentine surface). The statistical evaluation was performed using ANOVA and Tukey-test (p < 0.05). At all observation periods the CR showed the significant highest shear bond strength (p < 0.05). After 2d significant differences in the shear bond strength were detectable between all tested materials, whereby CR had the highest and MTA the lowest values (p < 0.05). After 7d and 14d the shear bond strengths of MTA and Biodentine increased significantly compared to the 2d investigation period (p < 0.05). Biodentine showed a significantly higher shear bond strength than MTA (p < 0.05), while the difference between Biodentine and GIC was not significant (p > 0.05). After 7d Biodentine showed comparable shear bond values than GIC, whereas the shear bond values for MTA were significantly lower even after 14d. The adhesion of Biodentine to dentine surface seams to be superior compared to that of MTA.

  20. Effect of root canal rinsing protocol on dentin bond strength of two resin cements using three different method of test

    PubMed Central

    Khoroushi, Maryam; Sheikhi, Mohammadreza; Soleimani, Bahram

    2016-01-01

    Background Different studies have used different tests to evaluate bond strength of resin cements to root dentin. In this in vitrostudy, three different tests were used to evaluate the bond strength of two resin cements to root dentin using two root dentin irrigation protocols. Material and Methods Ninety-six intact single-rooted teeth were selected for this study. Forty-eight teeth, with a root length of 15mm, were randomly divided into two groups and irrigated with normal saline or 2.5% sodium hypochlorite solutions during root canal preparation, respectively. For each 12 specimens from each group, fiber post #1 was bonded using an etch-and-rinse (Duo-Link) and a self-adhesive (BisCem) resin cement, respectively. After incubation, two specimens were prepared for the push-out test from the middle thirds of the roots. In another 24 teeth, after two 1.5-mm sections were prepared from the middle thirds of the prepared roots, sections of the post were bonded in two subgroups with each of the cements mentioned above and the samples were prepared for the pull-out test. For shear test, the crowns of 48 teeth were cut away, the dentin surfaces were prepared, the two irrigation solutions were used, and the resin cements were bonded. Data collected from the three tests were evaluated by ANOVA, post-hoc Tukey and Weibull tests (α=0.05). Results There were significant differences in the mean bond strength values between the three bond strength tests (P<0.001). Rinsing protocol and cement type resulted in similar variations in the mean bond strength in all tests (P>0.05). Conclusions Under the limitations of the present study, the method of the test used had an effect on the recorded bond strength between the resin cement and root dentin. Cement type and irrigation protocol resulted in similar variations with all the tests. Push-out and shear tests exhibited more coherent results. Key words:Bond strength, endodontically treated tooth, fiber post, resin cement, sodium

  1. Influence of glass fibre post length and remaining dentine thickness on the fracture resistance of root filled teeth.

    PubMed

    Junqueira, R B; de Carvalho, R F; Marinho, C C; Valera, M C; Carvalho, C A T

    2017-06-01

    To evaluate, ex vivo, the influence of glass fibre post length and remaining thickness of dentine on the fracture resistance of bovine roots, after thermomechanical ageing. Ninety bovine roots of the same size were root filled and randomly distributed into nine groups (n = 10), according to the root weakening protocol (NW - nonweakened; MW - medium weakened; HW - highly weakened) and post length (7 mm; 9 mm and 12 mm). The weakening of roots was performed using diamond burs, resulting in different thicknesses of remaining dentine. The post spaces were prepared, and in the weakened roots, the glass fibre posts were customized with composite resin, to create posts matching the canal size. Chemically activated resin cement was used to lute the posts. After luting, full crowns made of composite resin were attached to a silicon matrix. To reproduce physiological mobility, the roots were covered with polyether and embedded in polyurethane. The thermomechanical cycling was performed (1 200 000 cycles; 88N; 3,8 Hz; 5 ± 1 °C to 55 ± 1 °C). Then, the specimens were subjected to compressive force in a universal testing machine (1 mm min(-1) ; 100 kgf) to analyse the fracture resistance. The specimens were analysed through a stereomicroscope to classify the failure mode (repairable/catastrophic). The values were subjected to statistical analysis (two-way anova and Tukey's test at 5%). The frequencies of failure mode were compared using chi-square test. The association between length and dentine thickness was significant (P > 0.05). The difference was between NW and HW roots for posts of 12 mm in length. There was an association between failure mode and the length and remaining dentine thickness. Reduced dentine thickness in roots with longer posts had lower fracture resistance values, as catastrophic failure was more predominant. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  2. Crystallographic texture and elemental composition mapped in bovine root dentin at the 200 nm level.

    PubMed

    Deymier-Black, A C; Veis, A; Cai, Z; Stock, S R

    2014-01-01

    The relationship between the mineralization of peritubular dentin (PTD) and intertubular dentin (ITD) is not well understood. Tubules are quite small, diameter ∼2 µm, and this makes the near-tubule region of dentin difficult to study. Here, advanced characterization techniques are applied in a novel way to examine what organic or nanostructural signatures may indicate the end of ITD or the beginning of PTD mineralization. X-ray fluorescence intensity (Ca, P, and Zn) and X-ray diffraction patterns from carbonated apatite (cAp) were mapped around dentintubules at resolutions ten times smaller than the feature size (200 nm pixels), representing a 36% increase in resolution over earlier work. In the near tubule volumes of near-pulp, root dentin, Zn intensity was higher than in ITD remote from the tubules. This increase in Zn(2+), as determined by X-ray absorption near edge structure analysis, may indicate the presence of metalloenzymes or transcription factors important to ITD or PTD mineralization. The profiles of the cAp 00.2 X-ray diffraction rings were fitted with a pseudo-Voigt function, and the spatial and azimuthal distribution of these rings' integrated intensities indicated that the cAp platelets were arranged with their c-axes aligned tangential to the edge of the tubule lumen. This texture was continuous throughout the dentin indicating a lack of structural difference between in the Zn rich near-tubular region and the remote ITD.

  3. A randomised trial comparing the antibacterial effects of dentine primers against bacteria in natural root caries.

    PubMed

    Rolland, S L; McCabe, J F; Imazato, S; Walls, A W G

    2011-01-01

    As people are living longer and retaining their teeth into old age, root caries is an increasingly significant problem. A minimally invasive treatment strategy, involving sealing the root caries lesion with an antibacterial resin sealant, could be highly beneficial. The aim of this study was to compare the antibacterial properties of the primers of two proprietary dentine bonding agents, Clearfil SE Bond (SE; Kuraray Medical, Japan) and Clearfil Protect Bond (PB; Kuraray Medical), which contains the antibacterial monomer methacryloyloxydodecylpyridinium bromide. Fifty-two root caries lesions were identified and randomly assigned to a primer. The lesion was cleaned, isolated, sampled with a sharp spoon excavator, a primer applied and a second sample taken. Samples were transported in fastidious anaerobe broth, vortex-dispersed and serial dilutions inoculated onto selective agars. Reduction in colony-forming units (CFU, %) after primer application was calculated for both primers for bacterial growth on each selective agar and compared to a hypothesised mean of 100% (one-sample t test, p < 0.05). No significant differences between primers were seen, indicating efficient bacterial elimination by both materials. Comparing percent reduction between SE and PB for each agar (Mann-Whitney test, p < 0.05), a significantly greater CFU reduction by PB was seen for streptococci but not other bacteria. More lesions exhibited bacterial growth and several lesions demonstrated marked bacterial growth after treatment with SE compared with PB. Therefore, PB appears to exhibit superior antimicrobial properties, particularly against streptococci. Both primers are highly antibacterial towards root caries bacteria and may therefore be suitable for minimally invasive treatment.

  4. Age-related ransparent root dentin: mineral concentration,crystallite size and mechanical properties

    SciTech Connect

    Kinney, John H.; Nalla, Ravi K.; Pople, John A.; Breunig, Tom M.; Ritchie, Robert O.

    2004-12-29

    Many fractures occur in teeth that have been altered, forexample restored or endodontically repaired. It is therefore essential toevaluate the structure and mechanical properties of these altereddentins. One such altered form of dentin is transparent (sometimes calledsclerotic) dentin, which forms gradually with aging. The present studyfocuses on differences in the structure and mechanical properties ofnormal versus transparent dentin. The mineral concentration, as measuredby X-ray computed microtomography, was signifcantly higher in transparentdentin, the elevated concentration being consistent with the closure ofthe tubule lumens. Crystallite size, as measured by small angle X-rayscattering, was slightly smaller in transparent dentin, although theimportance of this ending requires further study. The elastic propertieswere unchanged by transparency; however, transparent dentin, unlikenormal dentin, exhibited almost no yielding before failure. In addition,the fracture toughness was lowered by roughly 20 percent while thefatigue lifetime was deleteriously affected at high stress levels. Theseresults are discussed in terms of the altered microstructure oftransparent dentin.

  5. Assessment of Photodynamic Therapy (PDT) in Disinfection of Deeper Dentinal Tubules in a Root Canal System: An In Vitro Study

    PubMed Central

    Bhaskar, Dara John; Agali, Chandan R; Punia, Himanshu; Gupta, Vipul; Singh, Vikas; Kadtane, Safalya; Chandra, Sneha

    2014-01-01

    Context: The success of endodontic treatment therapy depends on how well we eliminate pathogenic microflora from the root canal system as micro organism as the major cause of root canal infection. Conventional root canal treatment can fail if microorganisms cannot be removed sufficiently by thorough cleaning, shaping of root canal. Newer modalities such as photodynamic therapy are being tried now a days for disinfection of root canals. Aim & Objectives: The basic aim of this study was assessment of the antimicrobial efficacy of Photodynamic Therapy in deeper dentinal tubules for effective disinfection of root canals using microbiological and scanning electron microscopic examination in vitro. Materials and Methods: The study was conducted at Teerthanker Mahaveer Dental College & Research Centre. The teeth required for study was collected from Department of Oral and Maxillofacial Surgery. Only freshly extracted 20 intact, non carious single rooted teeth which were indicated for orthodontic treatment were taken for this study. Statistical analysis was done using Student’s Unpaired t-test were at (p<0.001) was found to be highly significant. Microbiological examination of samples were done and colony forming units were counted to assess the disinfection potential of photodynamic therapy. Scanning electron microscopic examination of samples was done to check penetration of bacteria’s into deeper dentinal tubules. Results: On examination, there was a marked reduction in microbial growth after use of photodynamic therapy. On scanning electron microscopic examination, it was observed that there were less number of bacteria’s in deeper dentinal tubules in case of PDT group as compared to control group. Conclusion: The results of the present study indicate that PDT can be effectively used during antimicrobial procedures along with conventional disinfection procedure for sterilization of root canals. PMID:25584321

  6. Effects of natural cross-linkers on the stability of dentin collagen and the inhibition of root caries in vitro.

    PubMed

    Walter, R; Miguez, P A; Arnold, R R; Pereira, P N R; Duarte, W R; Yamauchi, M

    2008-01-01

    To evaluate the effects of dentin collagen modifications induced by various cross-linkers on the stability of collagen matrix and the inhibition of root caries. The following cross-linkers were tested: 5% glutaraldehyde (GA), 0.5% proanthocyanidin (PA), 0.625% genipin (GE). In the first experiment, cross-linker-treated demineralized human root dentin was digested with bacterial collagenase, centrifuged, and the supernatants were subjected to amino acid analysis to determine collagen content. The residues were analyzed by SDS-PAGE and hydroxyproline analysis. In the second experiment, bovine root surfaces were conditioned with phosphoric acid, treated with the cross-linkers, incubated with Streptococcus mutans and Lactobacillus acidophilus for 1 week and the root caries inhibition was evaluated with confocal microscopy. Lastly, the ability of the bacteria to colonize the root surface was evaluated. In this experiment slabs of bovine root were treated with the cross-linkers and incubated in a suspension of S. mutans and L. acidophilus. The slabs were washed, resuspended in water, glucose was added, and the pH measured. While all collagen was digested with collagenase in the control groups, only a small proportion was solubilized in the GA-, PA-, and GE-treated groups. The root caries was significantly inhibited by treatment with PA or GA. Drops in pH in the cross-linker-treated groups were essentially the same as in the untreated group. Naturally occurring cross-linkers, especially PA, could be used to modify root dentin collagen to efficiently stabilize collagen and to increase its resistance against caries. Copyright 2008 S. Karger AG, Basel.

  7. Effects of Natural Cross-Linkers on the Stability of Dentin Collagen and the Inhibition of Root Caries in vitro

    PubMed Central

    Walter, R.; Miguez, P.A.; Arnold, R.R.; Pereira, P.N.R.; Duarte, W.R.; Yamauchi, M.

    2008-01-01

    Purpose To evaluate the effects of dentin collagen modifications induced by various cross-linkers on the stability of collagen matrix and the inhibition of root caries. Materials and Methods The following cross-linkers were tested: 5% glutaraldehyde (GA), 0.5% proanthocyanidin (PA), 0.625% genipin (GE). In the first experiment, cross-linker-treated demineralized human root dentin was digested with bacterial collagenase, centrifuged, and the supernatants were subjected to amino acid analysis to determine collagen content. The residues were analyzed by SDS-PAGE and hydroxyproline analysis. In the second experiment, bovine root surfaces were conditioned with phosphoric acid, treated with the cross-linkers, incubated with Streptococcus mutans and Lactobacillus acidophilus for 1 week and the root caries inhibition was evaluated with confocal microscopy. Lastly, the ability of the bacteria to colonize the root surface was evaluated. In this experiment slabs of bovine root were treated with the cross-linkers and incubated in a suspension of S. mutans and L. acidophilus. The slabs were washed, resuspended in water, glucose was added, and the pH measured. Results While all collagen was digested with collagenase in the control groups, only a small proportion was solubilized in the GA-, PA-, and GE-treated groups. The root caries was significantly inhibited by treatment with PA or GA. Drops in pH in the cross-linker-treated groups were essentially the same as in the untreated group. Conclusion Naturally occurring cross-linkers, especially PA, could be used to modify root dentin collagen to efficiently stabilize collagen and to increase its resistance against caries. PMID:18523385

  8. Effectiveness of Various Endodontic Irrigants on the Micro-Hardness of the Root Canal Dentin: An in vitro Study

    PubMed Central

    Saha, Suparna Ganguly; Bharadwaj, Anuj; Shrivastava, Poorvi; Saha, Mainak Kanti; Dubey, Sandeep; Kala, Shubham; Gupta, Shubhra

    2017-01-01

    Introduction Irrigating solutions used for the elimination of micro-organisms during root canal preparation may affect the chemical and the physical properties of dentin thereby rendering the tooth more susceptible to fracture. Therefore careful and judicious selection of irrigant is required which have maximum benefits with minimum undesirable properties. Aim The aim of the present study was to evaluate the effect of various endodontic irrigants on the micro-hardness of the root canal dentin. Materials and Methods This in vitro study was carried out on eighty freshly extracted mandibular premolars with single canals. They were decoronated at the cemento-enamel junction. Roots were sectioned longitudinally into two halves. They were then polished and placed in autopolymerised resin moulds with the polished surface facing outside. The samples were divided into four groups based on the irrigants in which they were immersed i.e., 3% Sodium Hypochlorite (3% NaOCl), 17% Ethylene Dioxide Tetra Acetic Acid (17% EDTA), 0.2% Chitosan and 6% Morindacitrifolia Juice (MCJ) for 15 minutes each. All the specimens were then subjected to micro-hardness testing using a Vickers micro-hardness tester. Statistical analysis was done using one way Analysis of Variance (ANOVA), Post-Hoc Tukey test and Paired t-test to compare the pre and post immersion micro-hardness values of the selected samples. Results The results of the present study indicated that 17% EDTA and 0.2% Chitosan, significantly decreased the micro-hardness of root dentin whereas 6% MCJ and 3% NaOCl had no significant effect on the microhardness before and after immersing in the irrigants. Conclusion A 6% MCJ and 3% NaOCl which have significant antibacterial, antifungal, anti-inflammatory and smear layer removing properties showed negligible effect on the micro-hardness of root canal dentin making them suitable endodontic irrigating solution. PMID:28571249

  9. Effect of Smear Clear and Some Other Commonly Used Irrigants on dislodgement resistance of Mineral Trioxide Aggregate to Root Dentin

    PubMed Central

    Sadegh, Mona; Sohrabi, Hasti; Kharazifard, Mohamadjavad

    2017-01-01

    Background This study aimed to assess the push-out bond strength of mineral trioxide aggregate (MTA) to root canal dentin after irrigation with Smear Clear in comparison with 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX) and saline as commonly used root canal irrigants. Material and Methods The coronal and mid-root areas of maxillary anterior teeth were horizontally sectioned into one-millimeter thick slices. The root canal lumen of dentinal slices was dilated using a diamond bur with 1.3 mm diameter. After the application of MTA, the samples were incubated in 100% humidity for 10 minutes and were then randomly divided into four groups (n=20) and immersed in Smear Clear, 2.5% NaOCl, 2% CHX and saline for 30 minutes. No irrigant was used for the control group (n=20). A wet cotton pellet was placed on the samples and after 48 hours of incubation, push-out bond strength was measured using a universal testing machine. The samples were evaluated under a stereomicroscope to determine the mode of failure. One-way ANOVA was used to assess statistical differences among the groups. Results The control group showed the highest bond strength with significant differences with other groups (P<0.05). Among the experimental groups, the saline group had no significant difference with CHX (P=0.09) but it had significant differences with Smear Clear and NaOCl groups (P<0.05). No significant difference in bond strength to MTA was noted after irrigation with Smear Clear, CHX and NaOCl (P>0.05). Other pairwise comparisons showed no significant difference (P>0.05). Conclusions Irrigation with Smear Clear, CHX and NaOCl did not cause a significant change in bond strength of MTA to dentin. Key words:Root Canal Irrigants, push-out, Mineral Trioxide Aggregate, dentin. PMID:28512536

  10. Effect of Smear Clear and Some Other Commonly Used Irrigants on dislodgement resistance of Mineral Trioxide Aggregate to Root Dentin.

    PubMed

    Sadegh, Mona; Sohrabi, Hasti; Kharazifard, Mohamadjavad; Afkhami, Farzaneh

    2017-05-01

    This study aimed to assess the push-out bond strength of mineral trioxide aggregate (MTA) to root canal dentin after irrigation with Smear Clear in comparison with 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX) and saline as commonly used root canal irrigants. The coronal and mid-root areas of maxillary anterior teeth were horizontally sectioned into one-millimeter thick slices. The root canal lumen of dentinal slices was dilated using a diamond bur with 1.3 mm diameter. After the application of MTA, the samples were incubated in 100% humidity for 10 minutes and were then randomly divided into four groups (n=20) and immersed in Smear Clear, 2.5% NaOCl, 2% CHX and saline for 30 minutes. No irrigant was used for the control group (n=20). A wet cotton pellet was placed on the samples and after 48 hours of incubation, push-out bond strength was measured using a universal testing machine. The samples were evaluated under a stereomicroscope to determine the mode of failure. One-way ANOVA was used to assess statistical differences among the groups. The control group showed the highest bond strength with significant differences with other groups (P<0.05). Among the experimental groups, the saline group had no significant difference with CHX (P=0.09) but it had significant differences with Smear Clear and NaOCl groups (P<0.05). No significant difference in bond strength to MTA was noted after irrigation with Smear Clear, CHX and NaOCl (P>0.05). Other pairwise comparisons showed no significant difference (P>0.05). Irrigation with Smear Clear, CHX and NaOCl did not cause a significant change in bond strength of MTA to dentin. Key words:Root Canal Irrigants, push-out, Mineral Trioxide Aggregate, dentin.

  11. Effectiveness of Various Endodontic Irrigants on the Micro-Hardness of the Root Canal Dentin: An in vitro Study.

    PubMed

    Saha, Suparna Ganguly; Sharma, Vini; Bharadwaj, Anuj; Shrivastava, Poorvi; Saha, Mainak Kanti; Dubey, Sandeep; Kala, Shubham; Gupta, Shubhra

    2017-04-01

    Irrigating solutions used for the elimination of micro-organisms during root canal preparation may affect the chemical and the physical properties of dentin thereby rendering the tooth more susceptible to fracture. Therefore careful and judicious selection of irrigant is required which have maximum benefits with minimum undesirable properties. The aim of the present study was to evaluate the effect of various endodontic irrigants on the micro-hardness of the root canal dentin. This in vitro study was carried out on eighty freshly extracted mandibular premolars with single canals. They were decoronated at the cemento-enamel junction. Roots were sectioned longitudinally into two halves. They were then polished and placed in autopolymerised resin moulds with the polished surface facing outside. The samples were divided into four groups based on the irrigants in which they were immersed i.e., 3% Sodium Hypochlorite (3% NaOCl), 17% Ethylene Dioxide Tetra Acetic Acid (17% EDTA), 0.2% Chitosan and 6% Morindacitrifolia Juice (MCJ) for 15 minutes each. All the specimens were then subjected to micro-hardness testing using a Vickers micro-hardness tester. Statistical analysis was done using one way Analysis of Variance (ANOVA), Post-Hoc Tukey test and Paired t-test to compare the pre and post immersion micro-hardness values of the selected samples. The results of the present study indicated that 17% EDTA and 0.2% Chitosan, significantly decreased the micro-hardness of root dentin whereas 6% MCJ and 3% NaOCl had no significant effect on the microhardness before and after immersing in the irrigants. A 6% MCJ and 3% NaOCl which have significant antibacterial, antifungal, anti-inflammatory and smear layer removing properties showed negligible effect on the micro-hardness of root canal dentin making them suitable endodontic irrigating solution.

  12. Cleaning efficacy and dentin micro-hardness after root canal irrigation with a strong acid electrolytic water.

    PubMed

    Qing, Yu; Akita, Yasumitsu; Kawano, Satoshi; Kawazu, Sukeyuki; Yoshida, Takakazu; Sekine, Ichiro

    2006-11-01

    The purpose of this study was to evaluate the cleaning effect of root canal walls using strong acid electrolytic water (SAEW) as a root canal irrigant, and to investigate the influence of SAEW on the root canal dentin by micro-hardness test. Forty-three single-rooted, single-canaled teeth were instrumented using standard step-back technique with K-files. Irrigation was performed using distilled water, 5.25% NaOCl and 3% H(2)O(2), SAEW, or 15% EDTA solution in five groups. Samples were prepared to be examined under a scanning electron microscope (SEM) and micro Vickers hardness (H(V)) test machine. Our results showed that the root cleaning effects of the combined use of SAEW and NaOCl solution as root canal irrigants were equivalent to those in the group with NaOCl and 15% EDTA. When SAEW was used for 1 min under ultrasonic vibration, no decreases in the hardness of dentin inside the root canal were detected.

  13. Effect of antibacterial varnishes applied to root dentin on shear bond strength of tooth-colored restorative materials.

    PubMed

    Korkmaz, Yonca; Baseren, Meserret

    2008-01-01

    This study investigated the effect of certain varnishes on the bond strength of different tooth-colored restorative materials applied to root dentin. One-hundred and eighty tooth slabs, including mesial and distal surfaces, were attained through dividing the teeth, then embedding them in methylmethacrylate. The root surfaces were ground flat through cementum, exposing the dentin. The samples were then randomly divided into three main groups: Group 1: Cervitec; Group 2: Fluor Protector and Group 3: No applications (control). Cervitec and Fluor Protector were applied to the root dentin surfaces according to the manufacturer's instructions. All the samples were kept in artificial saliva for six months. Each main group was subdivided into five groups of 12 teeth each: Group A: Flowable Resin Composite (Grandio Flow); Group B: Microhybrid Resin Composite (Artemis); Group C: Polyacid Modified Resin Composite (Dyract Extra); Group D: Resin Modified Glass Ionomer Cement (Vitremer) and Group E: Conventional Glass-Ionomer Cement (Ionofil Molar). Restorative materials were applied to the root dentin surfaces using a cylindrical mold. After thermocycling (1000 cycles, 5 degrees C/55 degrees C, dwell time 30 seconds), the shear bond strength of the restored samples was determined by a universal testing machine (Zwick Test Machine, Zwick GmbH & Co, Ulm, Germany) at a 5 mm/minute crosshead speed. Failure mode was determined under a stereomicroscope. The data were evaluated statistically by using one-way Analysis of Variance and Duncan tests (p< or =0.05). In the fluoride varnish group, all of the restorative materials except for Ionofil Molar, showed lower bond strengths when compared to the control group (p<0.05). In the Cervitec group, Artemis and Dyract Extra showed lower bond strengths; whereas, Ionofil Molar showed a higher bond strength than the control group (p<0.05). The highest percentage of cohesive fracture was observed in Artemis and Dyract Extra in the control group.

  14. Nondestructive assessment of dentin demineralization using polarization sensitive optical coherence tomography after exposure to fluoride and laser irradiation

    PubMed Central

    Manesh, Saman K.; Darling, Cynthia L.; Fried, Daniel

    2009-01-01

    Previous studies have demonstrated that polarization sensitive optical coherence tomography (PS-OCT) can be used to image natural and artificial caries in dentin. The purpose of this study was to measure non-destructively the severity of artificial caries lesions in dentin and determine the efficacy of intervention with anti-caries agents including fluoride and lasers. Although several studies have assessed the utility of PS-OCT to image caries lesions in enamel and to quantify the lesion severity, only a few studies have focused on lesions in dentin. In this study images of artificial dentin lesions on extracted human teeth were acquired with PS-OCT. Before exposure to an artificial demineralizing solution, three incisions were made on the sample surfaces using either Er:YAG, Nd:YAG (λ=355-nm), or TEA CO2 lasers and selected areas were treated with topical fluoride to create six unique treatment areas for each of the three laser conditions investigated. The integrated reflectivity and depth of demineralization were calculated for each of the six areas on each sample using the PS-OCT images. Polarized light microscopy (PLM) and transverse microradiography (TMR) were used to measure lesion severity on histological thin sections for comparison. PS-OCT successfully measured the inhibition of demineralization by topical fluoride. Laser irradiation was not particularly effective in increasing or decreasing the rate of dentin demineralization. PLM and TMR corroborated those results. This study demonstrates that PS-OCT can be used to measure demineralization on dentin surfaces and determine the degree of inhibition of demineralization by anti-caries agents. PMID:19283826

  15. Nondestructive assessment of dentin demineralization using polarization-sensitive optical coherence tomography after exposure to fluoride and laser irradiation.

    PubMed

    Manesh, Saman K; Darling, Cynthia L; Fried, Daniel

    2009-08-01

    Previous studies have demonstrated that polarization-sensitive optical coherence tomography (PS-OCT) can be used to image natural and artificial caries in dentin. The purpose of this study was to measure nondestructively the severity of artificial caries lesions in dentin and determine the efficacy of intervention with anticaries agents including fluoride and lasers. Although several studies have assessed the utility of PS-OCT to image caries lesions in enamel and to quantify the lesion severity, only a few studies have focused on lesions in dentin. In this study, images of artificial dentin lesions on extracted human teeth were acquired with PS-OCT. Before exposure to an artificial demineralizing solution, three incisions were made on the sample surfaces using either Er:YAG, Nd:YAG (lambda = 355 nm), or TEA CO(2) lasers and selected areas were treated with topical fluoride to create six unique treatment areas for each of the three laser conditions investigated. The integrated reflectivity and depth of demineralization were calculated for each of the six areas on each sample using the PS-OCT images. Polarized light microscopy (PLM) and transverse microradiography (TMR) were used to measure lesion severity on histological thin sections for comparison. PS-OCT successfully measured the inhibition of demineralization by topical fluoride. Laser irradiation was not particularly effective in increasing or decreasing the rate of dentin demineralization. PLM and TMR corroborated those results. This study demonstrates that PS-OCT can be used to measure demineralization on dentin surfaces and determine the degree of inhibition of demineralization by anticaries agents.

  16. Calcium loss from root canal dentin following EDTA and Tetracycline HCl Treatment with or without subsequent NaOCl irrigation and evaluation of microhardness of dentine

    NASA Astrophysics Data System (ADS)

    Mishra, Lora; Kumar, Manoj; Rao, C. V. Subba

    2012-07-01

    To assess Calcium loss from root canal dentin following EDTA and Tetracycline ñ HCL Treatment with or without subsequent NaOCl Irrigation and evaluation of microhardness of dentin. Materials and methods: Sixty freshly extracted single rooted premolars were selected.The teeth were sectioned l ongitudinally into two equal halves along the long axis using Diamond di sc. The one half of the specimen is used for the Calcium l oss eva luation by ICP-AES technique and the other one half with the acrylic block i s used for the micro hardness study. The data was analysed using One ñ way ANOVA and Post Hoc Tuckey test. Results: The maximum calcium loss was observed in Group V 17% EDTA +2.5% NaOCl (3.88 ± 0.30), followed by Group III 17% EDTA (3.46 ± 0.43 mg/L), Group VI 1% Tetracycline HCl + 2.5% NaOCl (1.71 ±0.28mg/L), Group IV Tetracycline HCl (1.46 ± 0.29mg/L). Group I distilled water (0.17± 0.25mg/L) and Group II 2.5% NaOCl (0.28± 0.05mg/L) had the least calcium loss value with p < 0.001. Dentin Microhardness i n Group I (67.6 ± 1.70 VHN), Group II (65.5 ± 3.57 VHN) Group IV and in Group VI ( 61.5± 1.09) showed significantly higher when compared to the mean values in Group III (59.7 ± 4.3 mg/L) and in Group V =(55.2±2.53VHN) withp<0.001. Conclusion: Group V 17% EDTA + 2.5% NaOCl resulted in maximum Calcium loss, but has reduced the microhardness. But Group VI 1%Tetracycline H Cl + 2.5% NaOCl solution e ffectively removed Calcium without much altering the microhardness of the r oot dentin .

  17. A New Weak Chelator in Endodontics: Effects of Different Irrigation Regimens with Etidronate on Root Dentin Microhardness

    PubMed Central

    Tartari, Talita; de Almeida Rodrigues Silva e Souza, Patrícia; Vila Nova de Almeida, Bruno; Carrera Silva Júnior, José Otávio; Facíola Pessoa, Oscar; Silva e Souza Junior, Mario Honorato

    2013-01-01

    This study investigated the effect of sodium hypochlorite (NaOCl), ethylenediaminetetraacetic (EDTA), etidronic (HEBP), and citric acid (CA) associated in different irrigation regimens on root dentin microhardness. Forty-five root halves of single-rooted teeth were sectioned into thirds that were embedded in acrylic resin, polished, randomly assigned into 3 groups, and treated as follows: G1: saline solution; G2: 5% NaOCl + 18% HEBP, mixed in equal parts; and G3: 2.5% NaOCl. After measurements, the G3 samples were distributed into subgroups G4, G5, and G6, which were submitted to 17% EDTA, 10% CA and 9% HEBP, respectively. Following the new measurements, these groups received a final flush with 2.5% NaOCl, producing G7, G8, and G9. Microhardness was measured with Knoop indenter under a 25 g load for 15 seconds, before and after treatments. The data were statistically analyzed using paired Student's t-test (α<0.05) to compare values before and after treatments and analysis of variance (ANOVA) (α<0.05) to detect any differences among thirds. Except G1, all tested irrigation regimens significantly decreased the microhardness. There were no differences between root thirds before treatments, and all root thirds exhibited equal responses to same treatment. Except saline, all tested irrigation regimens reduced the root dentin microhardness. PMID:23983692

  18. Bonding of photo and dual-cure adhesives to root canal dentin.

    PubMed

    Foxton, Richard M; Nakajima, Masatoshi; Tagami, Junji; Miura, Hiroyuki

    2003-01-01

    This study evaluated the regional tensile bond strength of a dual-cure resin composite core material to root canal dentin using photo and dual-cure adhesives and different modes of polymerization. Nineteen extracted premolars were decoronated and their root canals prepared to a depth of 8 mm and a width of 1.4 mm using Para Post drills. For the microtensile bond strength (microTBS) test, 15 roots were randomly divided into five groups and their canal walls treated with a dual-cure self-etching primer (Clearfil Liner Bond 2V Primer, Kuraray Medical Co, Japan). Adhesive resin (Clearfil Liner Bond 2V Bond A) was applied to two of the groups and light cured for 20 seconds. A dual-cure adhesive resin (Clearfil Liner Bond 2V Bond A+B, Kuraray Medical Co, Japan) was applied to the remaining three groups, one of which was light cured. The post spaces of all the groups were filled with a dual-cure resin composite (DC Core) and three were light cured for 60 seconds from a coronal direction. Chemical-cure resin composite was placed on the outer surfaces of the roots, which were then stored in water for 24 hours. They were serially sliced perpendicular to the bonded interface into eight 0.6 mm-thick slabs, then transversely sectioned into beams approximately 8 x 0.6 x 0.6 mm for the microTBS test. All of the failure modes were observed under SEM and analyzed using the Kruskal-Wallis Rank test. For Knoop hardness testing, four specimens were prepared in a similar manner, two were light-cured and the other two chemically-cured. The specimens were longitudinally sectioned into two pieces, and three indentations were made at 100 microm intervals from a coronal to an apical direction in the eight halves. Data were divided into two groups (coronal/apical halves of post space) and analyzed using two-way ANOVA and Scheffe's test (p<0.05). For each curing strategy, there were no significant differences in microTBS and Knoop hardness between the coronal and apical regions (p>0

  19. Effect of different surface treatments on the push-out bond strength of fiber post to root canal dentin.

    PubMed

    Demiryürek, Ebru Ozsezer; Külünk, Safak; Saraç, Duygu; Yüksel, Gözde; Bulucu, Bilinç

    2009-08-01

    The purpose of this study was to evaluate the effects of different surface treatments on the bond strength of a fiber post to dentin. Sixty extracted human maxillary incisor teeth were manually shaped with K-files using the step-back technique. ISO size 45 files were used as master apical files. Post spaces were prepared and then the root canals were subjected to one of the following 5 surface treatments: irrigation with 5% sodium hypochlorite (NaOCl); treatment with ethanol, ethyl acetate, and acetone-based cleansing agent (Sikko Tim); irrigation with 17% EDTA; etching with 37% orthophosphoric acid for 15 seconds; and etching with 10% citric acid for 15 seconds. Fiber posts were luted using self-etching/self-priming dual polymerized resin cement. From the coronal part of each root, 3 slides of 0.6-mm thickness were obtained. A push-out bond strength test was performed by a universal testing machine at a crosshead speed of 0.5 mm/min. Dentin surfaces were examined under scanning electron microscopy (SEM) after different surface treatments. Data were analyzed with a one-way analysis of variance (ANOVA) and Tukey HSD test. ANOVA revealed that canal surface treatment affected the bond strength (P < .001). The highest bond strength was obtained in the Sikko Tim group. The results also showed that surface treatment methods increased the bond strength to dentin when compared with the control group. Sikko Tim group was the more effective surface treatment agent compared with EDTA, orthophosphoric acid, citric acid, and control groups; however, it could not remove the smear layer and sealer remnants effectively on radicular dentin surfaces. Removal of the smear layer and opening of dentinal tubules are not recommended when a self-etching/self-priming adhesive system is used.

  20. Effect of the gutta-percha solvents on the microhardness and the roughness of human root dentine.

    PubMed

    Erdemir, A; Eldeniz, A U; Belli, S

    2004-11-01

    The purpose of this in vitro study was to evaluate the effect of gutta-percha solvents on the microhardness and the roughness of human root dentine. Forty-five recently extracted human mandibular anterior teeth were used. The teeth were sectioned longitudinally, embedded in acrylic resin and polished. Ninety specimens were divided into three groups containing 30 teeth each. In group 1, the specimens were treated with chloroform for 15 min. In group 2, the specimens were treated with halothane for 15 min. In group 3, distilled water was used and this group was served as control. All groups were then divided into two subgroups of 15 specimens each. The specimens, in groups 1a, 2a and 3a, were submitted to Vicker's microhardness indentations. Groups 1b, 2b and 3b were used for determination of the roughness of root dentine. The data were recorded as Vicker's numbers and Ra, mum for roughness test. The results were then analysed by one-way ANOVA and post hoc Tukey tests. The results indicated that chloroform and halothane did not affect the microhardness and the roughness of root dentine (P > 0.05).

  1. The effect of proanthocyanidins and chlorhexidine on the bond strength of glass fiber posts to root dentin.

    PubMed

    Alandia-Román, Carla Cecilia; Vincenti, Sergio Augusto Freitas; Silami, Francisca Daniele Jardilino; Silveira, Renata Espíndola; Pinto, Gustavo Col Dos Santos; Pires-de-Souza, Fernanda de Carvalho Panzeri

    2017-01-01

    In this study, the influence of different irrigant solutions applied before cementation on the bond strength (BS) of glass fiber posts to root dentin was evaluated. Thirty endodontically treated maxillary canines of similar length were selected and divided into 3 groups (n = 10) according to the irrigant solution used before post cementation: 1% sodium hypochlorite (NaOCl; control), 2% chlorhexidine (CHX), or a 6.5% grape seed extract (GSE) cross-linking agent. After cementation of the posts, the roots were transversely sectioned to create 2 discs (2 mm) for each of the root thirds: coronal, middle, and apical. These discs were submitted to push-out tests (0.5 mm/min) to evaluate the BS between the glass fiber posts and the root dentin. Statistical analysis was performed by a 2-way analysis of variance and a Tukey test (P < 0.05). The failure mode was evaluated in all specimens. Both the CHX and GSE groups presented significantly higher BS values than the control group in all root thirds (P < 0.05). The values of the GSE group were significantly higher than those of the CHX group in all thirds except the apical third (P < 0.05). In the control group, the BS value was highest in the cervical third. There was no significant difference in the BS values between the cervical and middle thirds when CHX was used (P > 0.05); however, the BS value diminished significantly in the apical third (P < 0.05). The highest BS value in the GSE group was found in the middle third. The results showed that the use of either GSE or CHX before adhesive cementation improved the BS of glass fiber posts to root dentin.

  2. Dentinal tubule penetration of AH Plus, iRoot SP, MTA fillapex, and guttaflow bioseal root canal sealers after different final irrigation procedures: A confocal microscopic study.

    PubMed

    Akcay, Merve; Arslan, Hakan; Durmus, Nazli; Mese, Merve; Capar, Ismail Davut

    2016-01-01

    Varied physical and chemical characteristic of root canal sealers and different irrigant agitation systems can influence the depth of penetration. The aim of this in vitro study was to use a laser scanning confocal microscope in order to assess the dentinal tubules penetration of various sealers after the application of different final irrigation techniques. A total of 156 single-rooted extracted mandibular premolars were prepared up to size 40 and randomly distributed into four groups according to the sealer type (n = 39): AH Plus, iRoot SP, MTA Fillapex, and GF Bioseal. Each group was randomly subdivided into three groups according to the final irrigation protocol (n = 13): conventional needle irrigation (CI), photon-induced-photoacoustic streaming activation (PIPS), and passive ultrasonic irrigation (PUI). After the final irrigation procedures, the root canals were obturated with single gutta-percha and labeled sealer mixed with 0.1% fluorescent rhodamine B isothiocyanate. Specimens were sectioned at 2, 5, and 8 mm from the apex, and all the sections were examined under confocal microscope to calculate the dentinal tubule penetration area. Data were analyzed using three-way analysis of variance and Tukey's post hoc tests (P = 0.05). iRoot SP exhibited a significantly higher penetration area than the other groups (P < 0.001), although there were no statistically significant differences between AH Plus, MTA Fillapex, and GF Bioseal (P > 0.05). Er:YAG laser activation with PIPS and PUI had significantly higher penetration than CI (P < 0.001). Statistically significant differences were also determined at each root canal third (coronal > middle > apical; P < 0.001). The dentinal tubule penetration area was significantly affected by the selection of root canal sealer, final irrigation procedure, and root canal third. Use of iRoot with PIPS tip or PUI seems advantageous in dentinal tubule penetration. © 2016 Wiley Periodicals, Inc.

  3. Forensic dental age estimation by measuring root dentin translucency area using a new digital technique.

    PubMed

    Acharya, Ashith B

    2014-05-01

    Dentin translucency measurement is an easy yet relatively accurate approach to postmortem age estimation. Translucency area represents a two-dimensional change and may reflect age variations better than length. Manually measuring area is challenging and this paper proposes a new digital method using commercially available computer hardware and software. Area and length were measured on 100 tooth sections (age range, 19-82 years) of 250 μm thickness. Regression analysis revealed lower standard error of estimate and higher correlation with age for length than for area (R = 0.62 vs. 0.60). However, test of regression formulae on a control sample (n = 33, 21-85 years) showed smaller mean absolute difference (8.3 vs. 8.8 years) and greater frequency of smaller errors (73% vs. 67% age estimates ≤ ± 10 years) for area than for length. These suggest that digital area measurements of root translucency may be used as an alternative to length in forensic age estimation.

  4. Human dental enamel and dentin structural effects after Er:YAG laser irradiation.

    PubMed

    Lima, Darlon Martíns; Tonetto, Mateus Rodrigues; de Mendonça, Adriano Augusto Melo; Elossais, André Afif; Saad, José Roberto Cury; de Andrade, Marcelo Ferrarezi; Pinto, Shelon Cristina Souza; Bandéca, Matheus Coelho

    2014-05-01

    Ideally projected to be applied on soft tissues, infrared lasers were improved by restorative dentistry to be used in hard dental tissues cavity preparations--namely enamel and dentin. This paper evidentiates the relevant aspects of infrared Erbium laser's action mechanism and its effects, and characterizes the different effects deriving from the laser's beams emission. The criteria for use and selection of optimal parameters for the correct application of laser systems and influence of supporting factors on the process, such as water amount and its presence in the ablation process, protection exerted by the plasma shielding and structural factors, which are indispensable in dental tissues cavity preparation related to restorative technique, are subordinated to optical modifications caused by the interaction of the energy dissipated by these laser light emission systems in the targeted tissue substrate. Differences in the action of infrared Erbium laser system in regard to the nature of the ablation process and variations on the morphological aspects observed in the superficial structure of the target tissue irradiated, may be correlated to the structural optical modifications of the substrate produced by an interaction of the energy propagated by laser systems.

  5. A simple method to detect gamma irradiated onions and shallots by root morphology

    NASA Astrophysics Data System (ADS)

    Selvan, Emily; Thomas, Paul

    1999-07-01

    A method based on root numbers and root length is proposed to discriminate irradiated onions and shallots from nonirradiated and chemically (maleic hydrazide) sprout inhibited bulb crops. Irradiated bulbs when placed in contact with water for a period of 24-72 h there was a drastic reduction in both number of roots and root length. In maleic hydrazide treated onions there was no inhibition in rooting efficiency. Irradiated bulbs placed on 0.2% agar showed drastic inhibition in only root length.

  6. Effect of 2% chlorhexidine digluconate on bond strength of a glass-fibre post to root dentine.

    PubMed

    Wang, L; Pinto, T A; Silva, L M; Araújo, D F G; Martins, L M; Hannas, A R; Pedreira, A P R V; Francisconi, P A S; Honório, H M

    2013-09-01

    To assess the immediate influence of dentine bonding systems (DBS) associated with 2% chlorhexidine digluconate (CHX) on glass-fibre post-bond strength to root dentine, in terms of coronal, middle and apical thirds. Sixty bovine roots were root filled and randomly assigned to 1 of 6 groups (n = 10): SBMP (3-step etch-and-rinse system, Scotchbond Multi-Purpose), SB (2-step etch-and-rinse system, Single Bond 2), SE (2-step self-etching system, Clearfil SE Bond) and SBMP-CHX, SB-CHX and SE-CHX, respectively, associated with CHX. For all groups, a glass-fibre post was luted with a dual-cure resin cement, RelyX ARC. After 7-day storage, specimens were subjected to the push-out test. Failure modes were analysed under optical microscopy (40x). Bond strength values were statistically analysed by two-way anova and Bonferroni tests (P < 0.05). The effect of DBS was significant (P < 0.05), and SE reached higher bond strength in comparison with the other DBS tested. CHX association did not show improvement with any DBS (P > 0.05); rather, it negatively affected SE, which was detected for all thirds. There was no difference between thirds (P > 0.05), except for the SE-CHX, which presented lower values for the apical third (P < 0.05). Adhesive cement/dentine adhesive failure was predominant for all groups. CHX did not influence the failure mode for any DBS (P > 0.05). The performance of the dentine bonding systems was material dependent. CHX did not improve immediate bond strength; however, CHX negatively affected the bond strength of the self-etching system, especially in the third apical. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  7. Effect of Er,Cr:YSGG Laser Irradiation with Radial Firing Tips on Candida albicans in Experimentally Infected Root Canals

    PubMed Central

    2014-01-01

    Aim. To compare the disinfection effect of Er,Cr:YSGG laser using radial firing tips with NaOCI in root canals infected with C. albicans and to evaluate the irradiation effect on the dentinal surfaces. Material and Methods. In total seventy-six mandibular premolar teeth were used. In order to standardize the incubation and sterilization procedure, eight teeth were used. Sixty-eight of the root canals were incubated with C. albicans suspension for 72 hours. The specimens were divided into 5 experimental groups. Two groups were constituted as Group 1 was irradiated with 1.5 W laser (n = 8) and group 2, which was irradiated with 2 W laser (n = 8). Two more groups were formed as Group 3 (2 W laser (n = 25) and Group 4 NaOCI (5%) (n = 25). Group 5 (n = 2) did not receive any treatment. Mann-Whitney U and Kruskal-Wallis H tests were used to compare the different laser output powers. Wilcoxon Signed Ranks Test was used in order to compare the Candida cfu/ml levels according to treatment protocols (P < 0.05). Results. Both 1.5 W and 2 W laser resulted in a major reduction of C. albicans without a significant difference. The comparison of the dentin surfaces irradiated with Er,Cr:YSGG laser at two power settings resulted in similar morphological changes. However, NaOCI was found to be more effective in reduction of C. albicans than 2 W laser application. Conclusion. According to the results of the present study, the Er,Cr:YSGG laser with radial firing tips presented less antifungal effects on C. albicans in root canals of infected teeth than NaOCl solution. PMID:24955367

  8. Impact of combined CO2 laser irradiation and fluoride on enamel and dentin biofilm-induced mineral loss.

    PubMed

    Esteves-Oliveira, Marcella; El-Sayed, Karim Fawzy; Dörfer, Christof; Schwendicke, Falk

    2017-05-01

    The caries-protective effects of CO2 laser irradiation on dental enamel have been demonstrated using chemical demineralization models. We compared the effect of CO2 laser irradiation, sodium fluoride, or both on biofilm-induced mineral loss (∆Z) and Streptococcus mutans adhesion to enamel and dentin in vitro. Ground, polished bovine enamel, and dentin samples were allocated to four groups (n = 12/group): no treatment (C); single 22,600-ppm fluoride (F) varnish (5 % NaF) application; single CO2 laser treatment (L) with short pulses (5 μs/λ = 10.6 μm); and laser and subsequent fluoride treatment (LF). Samples were sterilized and submitted to an automated mono-species S. mutans biofilm model. Brain heart infusion plus 5 % sucrose medium was provided eight times daily, followed by rinses with artificial saliva. After 10 days, bacterial numbers in biofilms were enumerated as colony-forming units/ml (CFU/ml) (n = 7/group). ∆Z was assessed using transversal microradiography (n = 12/group). Univariate ANOVA with post hoc Tukey honestly-significant-difference test was used for statistical analysis. Bacterial numbers were significantly higher on dentin than enamel (p < 0.01/ANOVA). On dentin, LF yielded significantly lower CFUs than other groups (p = 0.03/Tukey), while no differences between groups were found for enamel. The lowest ∆Z in enamel was observed for L (mean/SD 2036/1353 vol%×μm), which was not only significantly lower than C (9642/2452 vol%×μm) and F (7713/1489 vol%×μm) (p < 0.05) but also not significantly different from LF (3135/2628 vol%×μm) (p > 0.05). In dentin, only LF (163/227) significantly reduced ∆Z (p < 0.05). CO2 laser irradiation did not increase adhesion of S. mutans in vitro. Laser treatment alone protected enamel against biofilm-induced demineralization, while a combined laser-fluoride application was required to protect dentin.

  9. Effect of irrigation technique for removal of triple antibiotic paste on bond strength of MTA to root dentin.

    PubMed

    Dumani, Aysin; Yilmaz, Sehnaz; Yoldas, Oguz; Bek, Zeliha Gonca

    2016-01-01

    This study evaluated the bond strength of mineral trioxide aggregate (MTA) to root canal dentin after the performance of various irrigation procedures to remove triple antibiotic paste (TAP). A total of 56 single-rooted human mandibular premolars were instrumented using a rotary system to size 40 and divided randomly into a control group (no intracanal dressing) and three experimental groups (TAP application for 28 days). TAP was then removed by rinsing with 10 mL 2.5% NaOCl using three irrigation systems (Vibringe sonic irrigation, CanalBrush, and syringe irrigation). The coronal and middle parts of root canals were then obturated with MTA. After storage for 1 week, each specimen was embedded in an acrylic block and sectioned horizontally (2-mm-thick slices) at two levels (coronal and middle). Bond strength of MTA to root canal dentin was assessed in 28 samples per group via push-out test using a universal testing machine. Data from the four groups were compared using one-way analysis of variance. Tukey's test was used for multiple comparisons. Push-out bond strength values were significantly higher in the control and Vibringe groups than in the CanalBrush and syringe irrigation groups (p < 0.001). TAP removal from root canals with the Vibringe irrigation system may increase the push-out bond strength of MTA compared with the use of the CanalBrush or syringe irrigation.

  10. Influence of dentin from the root canal walls and the pulp chamber floor on the pH of intracanal medicaments.

    PubMed

    Agrafioti, Anastasia; Tzimpoulas, Nestoras E; Kontakiotis, Evangelos G

    2013-05-01

    The objective of this study was to evaluate the alterations in the pH of calcium hydroxide (Ca[OH]2), 2% chlorhexidine (CHX) gel, and their combination after adding dentin powder from the root canal walls and the pulp chamber floor. Ca(OH)2 paste, 2% CHX gel, and their combination were examined. Dentin powder was obtained from the root canal walls and the pulp chamber floor of bovine teeth and added as 1.8% to the volume of the medications. The pH values of the mixtures were assessed immediately after preparation, after 24 hours, and on days 7 and 14. Data were analyzed statistically by analysis of variance and the Student's t test (P = .05). pH values of Ca(OH)2 were always above 12 in the presence or absence of dentin powder during the 14 days of the study. A significant decrease in pH values of Ca(OH)2 was observed after 14 days when dentin from the root canal wall was added (P < .001). The pH values of CHX gel were significantly increased by the presence of dentin (P = .001). The t test showed a significant difference in the increase of the pH values when the different dentin types were added (P = .002). The pH of the Ca(OH)2 and CHX gel combination was not influenced by dentin powder from the root canal walls, and a reduction was observed after 14 days, exactly like in the control group. The pH values of the combination did not alter after 14 days when pulp chamber floor dentin was added. The different dentin types variably affect the pH of Ca(OH)2 paste, 2% CHX gel, and their combination in the studied periods. Copyright © 2013. Published by Elsevier Inc.

  11. [Morphological and failure mode study of different fiber posts luted with different adhesive systems to root dentin].

    PubMed

    Zhang, Xiao; Li, Jin-Le; Hao, Liang

    2011-04-01

    To investigate the correlation of morphological characteristics and failure modes of two types of glass-fiber posts luted with self-adhesive resin cement and etch-and-rinse adhesive system. Thirty-six intact single-rooted premolars were collected and removed the crown. After root canal therapy, teeth were randomly divided into 4 groups. Group A: Self-adhesive with POPO fiber post. Group B: Etch-and-rinse with POPO fiber posts. Group C: Self-adhesive with Para Post. Group D: Etch-and-rinse with Para Post. Each root was sectioned into six 1 mm-thick serial slices and a push-out test was performed. The dentin-cement-post adhesive interface of each specimen and failure modes after fracture were evaluated by stereomicroscope observation. Interface morphology observe indicated that voids present in group B (64.2%) and D (66.7%) were significantly higher than group A (5.8%) and C (13.7%) (P < 0.001). Interface gaps appeared at the resin-dentine interface in group D (41.2%) were significantly higher than group A (13.5%) and C (11.8%) (P < 0.0083), and the failure modes in each group were significantly different (P < 0.0083) except for group A and B (P = 0.69). Voids present in cement layer were associated with the luting agent involved. Morphological characteristics of the fiber post-resin luting agent-root dentin adhesive interface were discrepant with failure modes in different root region. There were interaction between adhesive systems and fiber posts.

  12. The effect of using RC prep during root canal preparation on the incidence of dentinal defects.

    PubMed

    Adl, Alireza; Sedigh-Shams, Mahdi; Majd, Marjan

    2015-03-01

    The purpose of this in vitro study was to evaluate the effect of using RC Prep (Well-Prep, Vericom Co, Anyang, Korea) during root canal preparation on the incidence of defects in root canal walls. One hundred extracted mandibular incisors with single canals were randomly divided into 1 control group and 4 experimental groups (n = 20). The teeth in group 1 (control) were coronally flared with Gates Glidden drills (Mani, Japan), but no further preparation was made. All teeth in the experimental groups were first coronally flared with Gates Glidden drills and then prepared similarly by means of ProTaper instruments (Dentsply Maillefer, Ballaigues, Switzerland). The difference between the experimental groups was the following: in group 2, saline was used as an irrigation solution without the application of RC Prep; in group 3, teeth were irrigated with saline, and RC Prep was also applied to canals before the insertion of each file; in group 4, sodium hypochlorite (NaOCl) was used for irrigation without the application of RC Prep; and in group 5, both NaOCl and RC Prep were used. The apical root surface and horizontal sections 3, 6, and 9 mm from the apex were observed under a microscope. The presence of cracks was noted. The chi-square test and Fisher exact test were used for statistical analysis of differences between and among the groups. A significant difference was found between and among the 5 groups (P < .05). Group 4 (NaOCl), which had the highest number of cracked teeth, was significantly different from group 1 (control) (P < .05). RC Prep, with both saline and NaOCl, had no significant effect on the incidence of microcrack formation (P > .05). When data were pooled, regardless of whether RC Prep was used, there was a significant difference between saline (groups 2 + 3) and NaOCl (groups 4 + 5) (P < .05). RC Prep was unable to reduce the risk of dentinal defects. NaOCl caused more defects compared with saline. Copyright © 2015. Published by Elsevier Inc.

  13. Influence of multi-wavelength laser irradiation of enamel and dentin surfaces on surface morphology and permeability

    NASA Astrophysics Data System (ADS)

    Chang, Nai-Yuan N.; Jew, Jamison; Simon, Jacob C.; Chan, Kenneth H.; Lee, Robert C.; Fried, William A.; Cho, Jinny; Darling, Cynthia L.; Fried, Daniel

    2017-02-01

    UV and IR lasers can be used to specifically target protein, water, and the mineral phase of dental hard tissues to produce varying changes in surface morphology. In this study, we irradiated enamel and dentin surfaces with various combinations of lasers operating at 0.355, 2.94, and 9.4 μm, exposed those surfaces to topical fluoride, and subsequently evaluated the influence of these changes on surface morphology and permeability. Digital microscopy and surface dehydration rate measurements were used to monitor changes in the samples overtime. The surface morphology and permeability (dehydration rate) varied markedly with the different laser treatments on enamel. On dentin, fluoride was most effective in reducing the permeability.

  14. Effect of photon induced photoacoustic streaming (PIPS) on bond strength to dentine of two root canal filling materials.

    PubMed

    Miletić, Ivana; Chieffi, Nicoletta; Rengo, Carlo; Ferrari, Marco; Nathanson, Dan; Baraba, Anja

    2016-12-01

    The aim of this study was to evaluate the effect of photon induced photoacoustic streaming (PIPS) technique in combination with EDTA on bond strength of gutta-percha/AH Plus and Resilon/RealSeal SE root canal fillings to root dentine. Forty freshly extracted human maxillary anterior teeth with intact straight roots, were instrumented endodontically with rotating ProTaper instruments and randomly divided into two experimental groups. In group 1 (n = 20), root canals were rinsed for 1 minute with 2 ml of 17% EDTA. In group 2 (n = 20), Er:YAG laser, with a 14 mm long 400 μ diameter tapered PIPS tip, was used for 1 minute with 2 ml of 17% EDTA. The laser parameters used were: 20 mJ per pulse, 15 Hz, 50 microsecond. In each experimental group, half of the root canals (n = 10) were obturated with gutta-percha/AH Plus and other half (n = 10) with Resilon/RealSeal SE. A micropush-out test was performed on sectiond specimens of the filled roots using a universal testing machine and resistance to failure plus failure modes were determined. Both gutta-percha/AH Plus groups had higher bond strength to root dentin than the Resilon/RealSeal SE groups (P < 0.05). The smear layer removal protocol, with EDTA only or combining PIPS technique with EDTA, had no influence on bond strength of either gutta-percha/AH Plus, or Resilon/RealSeal SE (P > 0.05). Within the limitations of this study, it was found that the application of the PIPS technique did not have an affect on the push-out bond strength of Resilon/RealSeal SE root canal filling to dentin nor on the gutta-percha/AH Plus. A significant difference in bond strength was noted between the two root canal filling materials. Lasers Surg. Med. 48:951-954, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  15. 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

  16. 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.

  17. Effect of application time of maleic acid on smear layer removal and mechanical properties of root canal dentin.

    PubMed

    Wang, Lin; Zhao, Yu; Mei, Liqin; Yu, Haiyang; Muhammad, Ibrahim; Pan, Yihuai; Huang, Shengbin

    2017-01-01

    To evaluate the effect of maleic acid (MA) on the cleaning efficacy and mechanical properties of root canal dentine with respect to different time exposure. One hundred and eighty single-canal premolars were instrumented with rotary-files and then randomly assigned to test groups receiving 7% MA for 30 s, 45 s, 1 min, or 3 min or to control groups treated with 0.9% saline or 17% ethylenediaminetetraacetic acid for 45 s. The micro-hardness, nano-hardness and elastic modules were measured before and after treatment, while the amount of smear and erosion in the coronal, middle and apical thirds in root canal were evaluated by scanning electron microscopy, finally, the fracture strength was assessed by vertical root fracture testing. The efficacy of smear layer removal increased with increasing MA application time. The largest effect was observed at 45 s, even in the apical third, whereas the treatment for 1 min resulted in irreversible erosion of the dentine surface. The micro-hardness and nano-indentation testing confirmed that the micro- and nano-scale mechanical properties were significantly decreased after MA application for 1 min. Furthermore, the specimens treated with MA for 3 min presented the lowest fracture resistance among all groups. In contrast, the 45 s treatment appeared to increase the fracture resistance of the tooth. The cleaning efficacy and mechanical properties of root canal dentine varied with MA exposure time. The application of MA for 45 s was found to be the most promising for clinical use.

  18. Effect of the Type of Endodontic Sealer on the Bond Strength Between Fiber Post and Root Wall Dentin

    PubMed Central

    Mosharraf, Ramin; Zare, Sepideh

    2014-01-01

    Objectives: An important factor that interferes with the bonding between the root canal wall and resin cement is the root canal sealer remnant. There is controversy about the effect of eugenol-containing sealers on the bond strength between resin cements and fiber post. The aim of this study was to evaluate the effect of the type of endodontic sealer on the bond strength of FRC posts cemented with resin cement to the root canal wall. Materials and Methods: In this in vitro study, 20 extracted mandibular first premolars were endodontically treated and divided into two groups according to the endodontic sealer used (n=10): G1: AH26 (Resin based); and G2: Endofill (Eugenol-based). After preparing post space, adhesive resin cement (Panavia F 2.0) was used for cementation of the fiber post to the root canal dentin. Three 3 mm thick slices were obtained from each root. The push-out test was performed with a cross-head speed of 1 mm/minute. Two-way ANOVA and Tukey post hoc tests were used for analyzing data (α=0.05). Results: The two-way ANOVA showed that different root canal sealers (P=0.037) had significant effects on bond strength (BS), but root canal regions (P=0.811) and interaction between root canal sealers and root canal regions (P=0.258) had no significant effects on BS. Maximum and minimum mean values were observed in the AH26 group, the apical region and the Endofill group in the apical region, respectively. Post Hoc Tukey test revealed that there were no significant differences between different root canal regions in both cements (P>0.05). Conclusion: The region of root canal had no effect on the bond strength of cemented fiber posts to the root canal. Eugenol-based sealers (Endofill) significantly reduced the bond strength between fiber posts luted with resin cement to the root canal. PMID:25584058

  19. Effect of Photoactivation Timing on the Mechanical Properties of Resin Cements and Bond Strength of Fiberglass Post to Root Dentin.

    PubMed

    Pereira, R D; Valdívia, A D C M; Bicalho, A A; Franco, S D; Tantbirojn, D; Versluis, A; Soares, C J

    2015-01-01

    This study tested the hypothesis that photoactivation timing and resin cement affect mechanical properties and bond strength of fiberglass posts to root dentin at different depths. Fiberglass posts (Exacto, Angelus) were luted with RelyX Unicem (3M ESPE), Panavia F 2.0 (Kuraray), or RelyX ARC (3M ESPE) using three photoactivation timings: light curing immediately, after three minutes, or after five minutes. Push-out bonding strength, PBS (n=10) was measured on each root region (coronal, middle, apical). The elastic modulus (E) and Vickers hardness (VHN) of the cement layer along the root canal were determined using dynamic indentation (n=5). A strain-gauge test was used to measure post-gel shrinkage of each cement (n=10). Residual shrinkage stress was assessed with finite element analysis. Data were analyzed with two-way analysis of variance in a split-plot arrangement and a Tukey test (α=0.05). Multiple linear regression analysis was used to determine the influence of study factors. The five-minute delay photoactivation timing significantly increased the PBS for all resin cements evaluated. The PBS decreased significantly from coronal to apical root canal regions. The mean values for E and VHN increased significantly with the delayed photoactivation for RelyX Unicem and decreased from coronal to apical root regions for all resin cements with the immediate-curing timing. The PBS of fiber posts to root dentin, E, and VHN values were affected by the root canal region, photoactivation timing, and resin cement type. Shrinkage stress values decreased gradually with delayed photoactivation for all the cements.

  20. Control of dentin/root sensitivity during non-surgical and surgical periodontal treatment.

    PubMed

    Giassin, Nantin Panagiota; Apatzidou, Danae Anastasia; Solomou, Katerina; Mateo, Luis R; Panagakos, Fotinos S; Konstantinidis, Antonis

    2016-02-01

    To determine the efficacy of a desensitizing regimen compared to a control in preventing the occurrence and/or alleviating dentin/root sensitivity (DRS) following non-surgical (NSPT) and surgical periodontal treatment (SPT). Seventy-four chronic-periodontitis patients (CPP) were randomized into a test group (n = 38) using an in-office prophylaxis paste and a toothpaste at home both containing 8% arginine and calcium carbonate (Pro-Argin(™) Technology) or into a control group (n = 36) receiving a fluoride-free prophylaxis paste and a fluoride toothpaste. The examiner applied the assigned paste onto selected teeth for 3 s following NSPT and for 60 s before flap closure. Patients brushed with the assigned toothpaste twice daily throughout the study. DRS to air stimulus was assessed by the Schiff scale (0-3) and the Visual Analog Scale (VAS: 0-100 mm) six times over 17 weeks. In the test group, VAS scores significantly decreased at 8, 11 and 17 weeks from baseline (p ≤ 0.003) and Schiff scores at 8 and 11 weeks from baseline (p ≤ 0.014). The control group exhibited significant increases in VAS and Schiff during the study period (p ≤ 0.006). Marked inter-group differences were noted at all time points (p < 0.001). The combined use of desensitizing products (8% arginine and calcium carbonate) in-office and at-home prevented DRS development and maintained this effect for 17 weeks following NSPT and SPT. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Effect of Nd:YAG laser irradiation and fluoride application in the progression of dentin erosion in vitro.

    PubMed

    João-Souza, Samira Helena; Scaramucci, Tais; Hara, Anderson T; Aranha, Ana Cecilia Corrêa

    2015-12-01

    Nd:YAG laser and its association with fluoride have been proposed as an option for the prevention of dental erosion. This study evaluated the progression of existing dentin erosive lesions after treatment with different Nd:YAG laser (1064 nm) protocols, associated or not with fluoride. Erosive lesions were created with 1 % citric acid for 10 min in human dentin specimens. They were randomly assigned into eight groups (n = 15): no treatment (control), 1-min application of 2 % sodium fluoride gel (NaF), Nd:YAG1 (Nd:YAG laser irradiation 0.5 W; 50 mJ; ~41.66 J/cm(2); 10 Hz; 40 s; in contact), Nd:YAG2 (0.7 W; 70 mJ; ~62.50 J/cm(2); 10 Hz; 40 s; in contact), Nd:YAG3 (1 W; 100 mJ; ~54,16 J/cm(2); 10 Hz; 40 s; 1 mm unfocused), NaF + Nd:YAG1, NaF + Nd:YAG2, and NaF + Nd:YAG3. After treatment, the specimens were submitted to a 5-day erosion-remineralization cycling model, 6×/day. Dentin surface loss (SL) was evaluated with optical profilometry after the formation of the initial lesion; after treatment; and after days 1, 3, and 5. Data were statistically analyzed (alpha = 0.05). Significant differences were observed among the groups in all testing times (p < 0.001), except after initial lesion formation. Loss of dentin surface was observed after irradiation with all Nd:YAG laser protocols (p < 0.05). The association fluoride and laser did not differ significantly from laser alone. NaF showed the lowest values of SL and Nd:YAG2 and NaF + Nd:YAG2, the highest. Within the limitations of an in vitro study, it was concluded that laser irradiation, according to the parameters used, was not an appropriated approach to prevent dentin erosion progression, even when it was associated with fluoride.

  2. Push-out bond strength of self-adhesive methacrylate resin-based sealers to root dentin.

    PubMed

    Sun, Yan; Li, Yu-hong; Fan, Ming-wen

    2014-02-01

    This study examined the adhesive strength of two self-adhesive methacrylate resin-based sealers (MetaSEAL and RealSeal SE) to root dentin and compared them with RealSeal and AH Plus in properties. A total of 48 extracted human single-rooted teeth were used to prepare the 0.9-mm thick longitudinal tooth slice (each per tooth). Standardized simulated canal spaces of uniform dimensions were prepared in the middle of radicular dentin. After treated with 5.25% sodium hypochlorite (NaOCl) and 17% EDTA, tooth slices were allocated randomly to four groups (n=12) in terms of different sealers used: MetaSEAL, RealSeal SE, RealSeal, and AH plus groups. The simulated canal spaces were obturated with different sealers in each group. There were 10 slabs with 20 simulated canal spaces (n=20) used in each group for push-out testing. The failure modes and the ultrastructures of fractured sealer-dentin interfaces were examined. The remaining 2 slabs in each group underwent partial demineralization for observation of the ultrastructure of resin tags. The results showed that the push-out bond strength was 12.01±4.66 MPa in MetaSEAL group, significantly higher than that in the other three groups (P<0.05). Moreover, no statistically significant differences were noted in the push-out bond strength between RealSeal SE (5.43±3.68 MPa) and AH Plus (7.34±2.83 MPa) groups and between RealSeal SE and RealSeal (2.93±1.76 MPa) groups (P>0.05). Mixed failures were predominant in the fractured sealer-dentin interfaces in MetaSEAL and AH Plus groups, while adhesive failures were frequently seen in RealSeal SE and RealSeal groups. In conclusion, after complete removal of the smear layer, MetaSEAL showed superior bond ability to root dentin. The RealSeal SE is applicable in clinical practice, with its adhesive strength similar to that of AH Plus. The self-adhesive methacrylate resin-based sealer holds promise for use in endodontic treatment.

  3. Effect of high-energy X-ray irradiation on creep mechanisms in bone and dentin.

    PubMed

    Deymier-Black, Alix C; Singhal, Anjali; Yuan, Fang; Almer, Jonathan D; Brinson, L Catherine; Dunand, David C

    2013-05-01

    Under long-term loading creep conditions, mineralized biological tissues like bone are expected to behave in a similar manner to synthetic composites where the creeping matrix sheds load to the elastic reinforcement as creep deformation progresses. To study this mechanism in biological composites, creep experiments were performed at 37 °C on bovine compact bone and dentin. Static compressive stresses were applied to the samples, while wide- and small-angle scattering patterns from high energy synchrotron X-rays were used to determine, respectively, the elastic strain in the hydroxyapatite (HAP) platelets and the strain in the mineralized collagen fibril, as a function of creep time. In these highly irradiated biological composites, the reinforcing hydroxyapatite platelets progressively transfer some of their stress back to the softer protein matrix during creep. While such behavior can be explained by damage at the interface between the two phases, it is not consistent with measurements of the apparent moduli--the ratio of applied stress to elastic HAP strain measured throughout the creep experiments by elastic unload/load segments--which remained constant throughout the experiment and thus indicated good HAP/protein bonding. A possible explanation is a combination of X-ray and load induced interfacial damage explaining the shedding of load from the HAP during long term creep, coupled with interfacial re-bonding of the load-disrupted reversible bonds upon unloading, explaining the unaffected elastic load partitioning during unload/load segments. This hypothesis is further supported by finite element modeling which shows results mirroring the experimental strain measurements when considering interfacial delamination and a compliant interstitial space at the ends of the HAP platelets. Copyright © 2013. Published by Elsevier Ltd.

  4. Fracture Forces of Dentin after Surface Treatment with High Speed Drill Compared to Er:YAG and Er,Cr:YSGG Laser Irradiation.

    PubMed

    Franzen, Rene; Kianimanesh, Nasrin; Marx, Rudolf; Ahmed, Asma; Gutknecht, Norbert

    2016-01-01

    Dental tooth restorative procedures may weaken the structural integrity of the tooth, with the possibility of leading to fracture. In this study we present findings of coronal dentin strength after different techniques of surface modification. The fracture strength of dentin beams after superficial material removal with a fine diamond bur high speed drill hand piece, Er:YAG (2.94 μm, 8 J/cm(2)), and Er,Cr:YSGG (2.78 μm, 7.8 J/cm(2)) laser irradiation slightly above the ablation threshold was measured by a four-point bending apparatus. Untreated dentin beams served as a control. A total of 58 dentin beams were manufactured from sterilized human extracted molars using the coronal part of the available dentin. Mean values of fracture strength were calculated as 82.0 ± 27.3 MPa for the control group (n = 10), 104.5 ± 26.3 MPa for high speed drill treatment (n = 10), 96.1 ± 28.1 MPa for Er,Cr:YSGG laser irradiation (n = 20), and 89.1 ± 36.3 MPa for Er:YAG laser irradiation (n = 18). Independent Student's t-tests showed no significant difference between each two groups (p > 0.05). Within the parameter settings and the limits of the experimental setup used in this study, both lasers systems as well as the high speed drill do not significantly weaken coronal dentin after surface treatment.

  5. Effects of diode laser (810 nm) irradiation on root canal walls: thermographic and morphological studies.

    PubMed

    da Costa Ribeiro, Adriana; Nogueira, Gessé Eduardo Calvo; Antoniazzi, João Humberto; Moritz, Andreas; Zezell, Denise Maria

    2007-03-01

    This study investigated the thermal effects and the morphological changes after diode laser irradiation (810 nm) of root canals. Samples were irradiated at 2.5 W, 1,989 W/cm2 (group 2) and 1.25 W, 10 Hz, 994 W/cm2 (group 3), with group 1 being the control group of nonirradiated samples. The temperature rise was evaluated using an infrared thermographic camera, and the morphological changes were assayed by scanning electron microscopy (SEM). The SEM images revealed closed dentinal tubules, especially at the apical regions when compared with the control samples. The maximum temperature variations at the apical region were analyzed, and the resulting 95% confidence intervals of the medians (Wilcoxon) ranged from 1.6 to 8.6 degrees C (group 2) and from 1.2 to 3.3 degrees C (group 3). The results suggest that the diode laser can be used for endodontic purposes and show that the method is safe for periodontal tissues at the investigated parameters.

  6. CBCT Assessment of Root Dentine Removal by Gates-Glidden Drills and Two Engine-Driven Root Preparation Systems

    PubMed Central

    Harandi, Azade; Mohammadpour Maleki, Fatemeh; Moudi, Ehsan; Ehsani, Maryam; Khafri, Soraya

    2017-01-01

    Introduction: The aim of this study was to compare the dentine removing efficacy of Gates-Glidden drills with hand files, ProTaper and OneShape single-instrument system using cone-beam computed tomography (CBCT). Methods and Materials: A total of 39 extracted bifurcated maxillary first premolars were divided into 3 groups (n=13) and were prepared using either Gates-Glidden drills and hand instruments, ProTaper and OneShape systems. Pre- and post-instrumentation CBCT images were obtained. The dentin thickness of canals was measured at furcation, and 1 and 2 mm from the furcation area in buccal, palatal, mesial and distal walls. Data were analyzed using one-way ANOVA test. Tukey’s post hoc tests were used for two-by-two comparisons. Results: Gates-Glidden drills with hand files removed significantly more (P<0.001) dentine than the engine-driven systems in all canal walls (buccal, palatal, mesial and distal). There were no significant differences between OneShape and ProTaper rotary systems (P>0.05). Conclusion: The total cervical dentine removal during canal instrumentation was significantly less with engine-driven file systems compared to Gates-Glidden drills. There were no significant differences between residual dentine thicknesses left between the various canal walls. PMID:28179920

  7. Ablation of healthy and carious enamel and dentin by erbium:YAG laser irradiation

    NASA Astrophysics Data System (ADS)

    Roth, Klaus K.; Duczynski, Edwin W.

    1995-04-01

    The purpose of this study was to determine the ablation rates of healthy and carious enamel and dentin on extracted human permanent molars and premolars. Measurements were taken using a flash lamp pumped pulsed 2.94 micrometers CrEr:YAG laser (pulse length 200 microsecond(s) , energy density 2-20 J/cm2, f equals 1-2 Hz). Teeth were cut into slices of 2 mm thickness and the ablation rates of 1450 craters were measured as a function of the energy density and pulse number. Clearly higher degrees of ablation were observed in dentin than in enamel with most effective ablation rates in carious enamel and dentin. Ablation thresholds in enamel, dentin and caries could not be detected. However, it could not be shown that there is any selectivity in caries removal by Erbium:YAG laser radiation.

  8. Dentinal damage and fracture resistance of oval roots prepared with single-file systems using different kinematics.

    PubMed

    Abou El Nasr, Hend Mahmoud; Abd El Kader, Karim Galal

    2014-06-01

    Vertical root fracture is a common finding in endodontically treated teeth, notably oval roots. The aim of the present study was to determine the effect of instrumentation kinematics and the material of instrument construction of single-file systems on dentin walls and fracture resistance of oval roots. Sixty-five roots with oval canals were allocated into a control group (n = 5) and 3 experimental groups of 20 roots each. Group WO was instrumented with the WaveOne primary file (Dentsply Maillefer, Baillagues, Switzerland), group PT-Rec was prepared with F2 ProTaper files (Dentsply Maillefer, Baillagues, Switzerland) used in a reciprocating motion, and group PT-Rot was prepared with F2 ProTaper files used in a rotation motion. For crack evaluation, half of the samples (n = 30) were embedded in acrylic resin, and the blocks were sectioned at 3, 6, and 9 mm from the apex. The sections were examined under a stereomicroscope and scored for crack presence. The other half of the specimens (n = 30) were obturated using lateral condensation of gutta-percha and AdSeal sealer (Meta Biomed Co, Ltd, Chungbuk, Korea). The specimens were then subjected to a load of 1 mm/min to determine the force required to fracture the roots. WaveOne instruments induced the least amount of cracks and exhibited greatest resistance to fracture compared with ProTaper F2 files whether used in reciprocating or rotating motions. The alloy from which the material is manufactured is a more important factor determining the dentin damaging potential of single-file instruments than the motion of instrumentation. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  9. Push-out bond strength and dentinal tubule penetration of different root canal sealers used with coated core materials.

    PubMed

    Deniz Sungur, Derya; Purali, Nuhan; Coşgun, Erdal; Calt, Semra

    2016-05-01

    The aim of this study was to compare the push-out bond strength and dentinal tubule penetration of root canal sealers used with coated core materials and conventional gutta-percha. A total of 72 single-rooted human mandibular incisors were instrumented with NiTi rotary files with irrigation of 2.5% NaOCl. The smear layer was removed with 17% ethylenediaminetetraacetic acid (EDTA). Specimens were assigned into four groups according to the obturation system: Group 1, EndoRez (Ultradent Product Inc.); Group 2, Activ GP (Brasseler); Group 3, SmartSeal (DFRP Ltd. Villa Farm); Group 4, AH 26 (Dentsply de Trey)/gutta-percha (GP). For push-out bond strength measurement, two horizontal slices were obtained from each specimen (n = 20). To compare dentinal tubule penetration, remaining 32 roots assigned to 4 groups as above were obturated with 0.1% Rhodamine B labeled sealers. One horizontal slice was obtained from the middle third of each specimen (n = 8) and scanned under confocal laser scanning electron microscope. Tubule penetration area, depth, and percentage were measured. Kruskall-Wallis test was used for statistical analysis. EndoRez showed significantly lower push-out bond strength than the others (p < 0.05). No significant difference was found amongst the groups in terms of percentage of sealer penetration. SmartSeal showed the least penetration than the others (p < 0.05). The bond strength and sealer penetration of resin-and glass ionomer-based sealers used with coated core was not superior to resin-based sealer used with conventional GP. Dentinal tubule penetration has limited effect on bond strength. The use of conventional GP with sealer seems to be sufficient in terms of push-out bond strength.

  10. Push-out bond strength and dentinal tubule penetration of different root canal sealers used with coated core materials

    PubMed Central

    Purali, Nuhan; Coşgun, Erdal; Calt, Semra

    2016-01-01

    Objectives The aim of this study was to compare the push-out bond strength and dentinal tubule penetration of root canal sealers used with coated core materials and conventional gutta-percha. Materials and Methods A total of 72 single-rooted human mandibular incisors were instrumented with NiTi rotary files with irrigation of 2.5% NaOCl. The smear layer was removed with 17% ethylenediaminetetraacetic acid (EDTA). Specimens were assigned into four groups according to the obturation system: Group 1, EndoRez (Ultradent Product Inc.); Group 2, Activ GP (Brasseler); Group 3, SmartSeal (DFRP Ltd. Villa Farm); Group 4, AH 26 (Dentsply de Trey)/gutta-percha (GP). For push-out bond strength measurement, two horizontal slices were obtained from each specimen (n = 20). To compare dentinal tubule penetration, remaining 32 roots assigned to 4 groups as above were obturated with 0.1% Rhodamine B labeled sealers. One horizontal slice was obtained from the middle third of each specimen (n = 8) and scanned under confocal laser scanning electron microscope. Tubule penetration area, depth, and percentage were measured. Kruskall-Wallis test was used for statistical analysis. Results EndoRez showed significantly lower push-out bond strength than the others (p < 0.05). No significant difference was found amongst the groups in terms of percentage of sealer penetration. SmartSeal showed the least penetration than the others (p < 0.05). Conclusions The bond strength and sealer penetration of resin-and glass ionomer-based sealers used with coated core was not superior to resin-based sealer used with conventional GP. Dentinal tubule penetration has limited effect on bond strength. The use of conventional GP with sealer seems to be sufficient in terms of push-out bond strength. PMID:27200279

  11. Effects of endodontic irrigation solutions on mineral content of root canal dentin using ICP-AES technique.

    PubMed

    Ari, Hale; Erdemir, Ali

    2005-03-01

    The aim of this in vitro study was to evaluate mineral content of root canal dentin after treatment with several endodontic irrigation solutions. Sixty mandibular anterior teeth extracted for periodontal reasons used. The crowns of the teeth were removed at the cemento-enamel junction. Pulp tissues were removed and the teeth were randomly divided into six groups including 10 teeth each. Root canals were enlarged with gates-glidden burs (# 1, 2, and 3). The groups were treated as follows: group 1, 0.2% chlorhexidine gluconate for 15 min; group 2, 3% H2O2 for 15 min; group 3, 17% EDTA for 15 min; group 4, 5.25% NaOCl for 15 min; group 5, 2.5% NaOCl for 15 min; and group 6, distilled water (control). Dentin chips were obtained using gates-glidden burs (# 4, 5, and 6). The levels of five elements calcium, phosphorus, magnesium, potassium, and sulfur in each specimens were analyzed using ICP-AES (Inductively Coupled Plasma Atomic Emission Spectrometry) technique. Changes in the levels of the chemical elements were recorded. The results were then statistically analyzed by one-way ANOVA and Tukey tests. There was a significant decrease in the calcium and phosphorus levels after treatment with all irrigation solutions except for 5.25% NaOCl when compared with the control group (p < 0.05). The K, Mg, and S level changes were not statistically significant (p > 0.05). It has been concluded that endodontic irrigation solutions have an effect on mineral contents of root dentin.

  12. The Hidden Treasure in Apical Papilla: The Potential Role in Pulp/Dentin Regeneration and BioRoot Engineering

    PubMed Central

    Huang, George T.-J.; Sonoyama, Wataru; Liu, Yi; Liu, He; Wang, Songlin; Shi, Songtao

    2009-01-01

    Some clinical case reports have shown that immature permanent teeth with periradicular periodontitis or abscess can undergo apexogenesis after conservative endodontic treatment. A call for a paradigm shift and new protocol for the clinical management of these cases has been brought to attention. Concomitantly, a new population of mesenchymal stem cells residing in the apical papilla of permanent immature teeth recently has been discovered and was termed stem cells from the apical papilla (SCAP). These stem cells appear to be the source of odontoblasts that are responsible for the formation of root dentin. Conservation of these stem cells when treating immature teeth may allow continuous formation of the root to completion. This article reviews current findings on the isolation and characterization of these stem cells. The potential role of these stem cells in the following respects will be discussed: (1) their contribution in continued root maturation in endodontically treated immature teeth with periradicular periodontitis or abscess and (2) their potential utilization for pulp/dentin regeneration and bioroot engineering. PMID:18498881

  13. Dentinal crack formation during root canal preparations by the twisted file adaptive, Reciproc and WaveOne instruments.

    PubMed

    Gergi, Richard M; Osta, Nada E; Naaman, Alfred S

    2015-01-01

    This study aimed to compare the frequency of dentinal microcracks after root canal shaping with 2 reciprocating (Reciproc and WaveOne) and 1 combined continuous reciprocating motion twisted files adaptive (TFA) rotary system. Ninety molars were chosen and divided into three groups of 30 each. Root canal preparation was achieved by using Reciproc R25, Primary WaveOne and TFA systems. All the roots were horizontally sectioned at 15, 9, and 3 mm from the apex. The slices were then viewed each under a microscope at × 25 magnification to determine the presence of cracks. The absence/presence of cracks was recorded, and the data were analyzed with a Chi-square test. The significance level was set at P < 0.05. Instrumentation with Reciproc produced significantly more complete cracks than WaveOne and TFA (P = 0.032). The TFA system produced significantly less cracks then the Reciproc and WaveOne systems apically (P = 0.004). Within the limits of this study, the TFA system caused less cracks then the full reciprocating system (Reciproc and WaveOne). Single-file reciprocating files produced significantly more incomplete dentinal cracks than full-sequence adaptive rotary motion.

  14. Dentinal crack formation during root canal preparations by the twisted file adaptive, Reciproc and WaveOne instruments

    PubMed Central

    Gergi, Richard M.; Osta, Nada E.; Naaman, Alfred S.

    2015-01-01

    Objective: This study aimed to compare the frequency of dentinal microcracks after root canal shaping with 2 reciprocating (Reciproc and WaveOne) and 1 combined continuous reciprocating motion twisted files adaptive (TFA) rotary system. Materials and Methods: Ninety molars were chosen and divided into three groups of 30 each. Root canal preparation was achieved by using Reciproc R25, Primary WaveOne and TFA systems. All the roots were horizontally sectioned at 15, 9, and 3 mm from the apex. The slices were then viewed each under a microscope at × 25 magnification to determine the presence of cracks. The absence/presence of cracks was recorded, and the data were analyzed with a Chi-square test. The significance level was set at P < 0.05. Results: Instrumentation with Reciproc produced significantly more complete cracks than WaveOne and TFA (P = 0.032). The TFA system produced significantly less cracks then the Reciproc and WaveOne systems apically (P = 0.004). Conclusions: Within the limits of this study, the TFA system caused less cracks then the full reciprocating system (Reciproc and WaveOne). Single-file reciprocating files produced significantly more incomplete dentinal cracks than full-sequence adaptive rotary motion. PMID:26929688

  15. Prevention of dentine caries using silver diamine fluoride application followed by Er:YAG laser irradiation: an in vitro study.

    PubMed

    Mei, May L; Ito, Leticia; Chu, C H; Lo, Edward C M; Zhang, C F

    2014-11-01

    To evaluate the preventive effect of Er:YAG laser (EYL) irradiation followed by silver diamine fluoride (SDF) application on dentine with cariogenic biofilm challenge. Twenty-four dentine slices were prepared from extracted sound human third molars. Each slice was cut into four parts for SDF application, followed by EYL irradiation (group SL), SDF application (group S), EYL irradiation (group L) and water (group W). The specimens were subjected to cariogenic biofilm challenge for 12 h, followed by immersion in a buffered remineralising solution containing calcium chloride and sodium hypophosphate for 12 h at 37 °C. Surface morphological changes in the specimens were examined using scanning electronic microscopy. Elemental analysis was performed using energy-dispersive X-ray spectrometry. Micro-mechanical properties were investigated by nano-indentation. The specimen surfaces of groups SL and L showed laser melting contours with narrowed dentinal orifices. Group S showed a partial tubular occlusion. A porous surface was observed in group W, indicating demineralisation. The mean (SD) fluoride weight percentages were 3.93 (0.91), 3.10 (0.61), 0.17 (0.09) and 0.32 (0.07) in groups SL, S, L and W, respectively, (p < 0.001; SL, S > L, W). The mean (SD) micro-hardness values in GPa were 1.84 (0.22), 0.49 (0.13), 0.41 (0.11) and 0.30 (0.06) in groups SL, S, L and W, respectively, (p < 0.001; SL > S > L, W). The mean (SD) elastic moduli in GPa were 75.1 (7.2), 20.0 (1.3), 24.3 (5.2) and 20.2 (2.8) in groups SL, S, L and W, respectively, (p < 0.001; SL > S, L, W). SDF application followed by EYL irradiation on a dentine surface increased its resistance to cariogenic biofilm challenge.

  16. The effect of three different antioxidants on the dentinal tubular penetration of Resilon and Real Seal SE on sodium hypochlorite-treated root canal dentin: An in vitro study

    PubMed Central

    Christopher, Sarah Renjelina; Mathai, Vijay; Nair, Rajesh Sasidharan; Angelo, Jeyabalaji Mano Christaine

    2016-01-01

    Objective: The effect of 10% ascorbic acid, 10% tannic acid, and 10% gallic acid on the dentinal tubular penetration of Resilon and Real Seal SE on sodium hypochlorite-treated root canal dentin was evaluated. Materials and Methods: Fifty human premolars were decoronated to attain 14-mm root length and divided into five groups of 10 teeth each. Biomechanical preparation was done with rotary instruments. Group I specimens were irrigated with saline and 17% ethylenediaminetetraacetic acid (EDTA). Specimens from groups II, III, IV, and V were irrigated with 5.25% sodium hypochlorite and 17% EDTA. Specimens from groups III, IV, and V underwent additional irrigation with antioxidants–10% ascorbic acid, 10% tannic acid, and 10% gallic acid, respectively. Following obturation with Resilon and Real Seal SE, scanning electron microscope (SEM) analysis was done to note the maximum dentinal tubular penetration at the cervical, middle, and apical thirds of each specimen. The data were statistically analyzed using one-way analysis of variance (ANOVA), Post hoc and Dunnett's test. Results: Maximum dentinal tubular penetration of Resilon and Real Seal SE was obtained following irrigation with 10% gallic acid. Conclusion: 10% gallic acid was superior among the antioxidant irrigants that enabled the increased dentinal tubular penetration of Resilon and Real Seal SE. PMID:27099424

  17. Marginal adaptation of mineral trioxide aggregate (MTA) to root dentin surface with orthograde/retrograde application techniques: A microcomputed tomographic analysis

    PubMed Central

    Al Fouzan, Khalid; Awadh, Mohammed; Badwelan, Moahmmed; Gamal, Abeer; Geevarghese, Amrita; Babhair, Samar; Al-Rejaie, Mansour; Al Hezaimi, Khalid; Rotstein, Ilan

    2015-01-01

    Background: Achieving a good apical seal for root canals is known to be associated with good mineral trioxide aggregate (MTA) adaptation to dentin. Aims: This study aims to compare the marginal adaptation of MTA with root dentin between orthograde and retrograde application techniques using microcomputed tomography (micro-CT) analysis. Settings and Design: Fifty-two single-rooted human teeth were divided into four equal groups: (Group 1) Retrograde MTA (RMTA), (Group 2) Orthograde MTA (OMTA), (Group 3) Etched RMTA (ERMTA), and (Group 4) Etched OMTA (EOMTA). Materials and Methods: For Group 1, 3-mm retrograde cavities were prepared and filled with MTA. For Group 2, the apical 6 mm of the canals were filled with MTA and sealed with sealer cement and warm gutta-percha. In Groups 3 and 4, canals were treated the same as Groups 1 and 2, respectively, except that before placing the MTA, canals were irrigated with 17% ethylenediaminetetraacetic acid (EDTA). After 48 hours, all the teeth were analyzed using a micro-CT scanner. Statistical Analysis: Mean dentin-MTA contact and the mean length and width of each gap was analysed using one-way analysis of variance (ANOVA). Statistical significance was set at an α level of 5%. Results: No significant difference in gap volumes was observed in the dentin-MTA adaptation in both orthograde and retrograde application techniques. However, significant difference in the gap volumes was observed between RMTA and ERMTA (P = 0.045). Etching significantly improved the MTA-Dentin adaptation (P < 0.05). The type of application technique did not significantly improve the dentin-MTA adaptation, instead with the use of 17% EDTA, a significant improvement could be achieved. Conclusion: Within the limitations of the present study, it concludes that MTA adaptation to dentin tooth structure is not significantly different between an orthograde and retrograde approach. However, the use of EDTA significantly improved the MTA-Dentin adaptation. PMID

  18. Evaluation of a new hardness tester (Cariotester): Comparison with transverse microradiography for assessing the inhibitory effect of fluoride application on bovine root dentin demineralization.

    PubMed

    Sugawara, Toyotaro; Nakashima, Syozi; Shimizu, Akihiko; Tagami, Junji; Momoi, Yasuko

    2015-01-01

    The objective of this study was to investigate the correlation between CT depth, indentation depth determined by a new hardness tester (Cariotester), and the transverse microradiography (TMR) parameters, i.e., lesion depth and mineral loss. For that purpose, this study evaluated the feasibility of using Cariotester as a root caries diagnostic system and capability of Cariotester to detect effect of fluoride application on inhibiting dentin demineralization. Fluorides were applied to bovine root dentin specimens, which were subsequently demineralized for 1-21 days and then CT depth and TMR parameters were assessed. There were significant correlations between CT depth and TMR parameters in fluoride and non-fluoride groups. There were significant differences between fluoride and non-fluoride groups for CT depth and TMR parameters respectively. Current results suggested that Cariotester may be capable of providing an objective evaluation of root caries progression and the fluoride effect on inhibiting dentin demineralization.

  19. The incidence of dentinal cracks during root canal preparations with reciprocating single-file and rotary-file systems: A meta-analysis.

    PubMed

    Wei, Xi; Hu, Bo; Peng, Haiyang; Tang, Ming; Song, Jinlin

    2017-03-08

    As a dangerous factor in vertical root fracture, dentinal crack formation is often associated with root canal instruments. We conducted this meta-analysis to compare the influence of two types of nickel titanium (NiTi) instruments that have different movements (reciprocating single-file versus full-sequence rotary file systems) on dentinal cracks formation during root canal preparation. Searches were conducted in PubMed, ISI Web of Knowledge, Embase and Cochrane Library using a combination of keywords. Titles and abstracts of all articles were independently assessed by two reviewers in accordance with the predefined inclusion criteria. Relevant studies were acquired in full-text form. Data in these articles were independently extracted. A meta-analysis was conducted using Review Manager 5.3. The results showed that the WaveOne and Reciproc files with a reciprocating motion produced significantly fewer dentinal cracks than the conventional rotational ProTaper technique.

  20. Experimental formation of dentin-like structure in the root canal implant model using cryopreserved swine dental pulp progenitor cells.

    PubMed

    Kodonas, Kostas; Gogos, Christos; Papadimitriou, Serafim; Kouzi-Koliakou, Kokona; Tziafas, Dimitrios

    2012-07-01

    The purpose of the present study was to present histological and immunohistochemical evidence showing the regenerative capacity of swine dental pulp stem cells (S-DPSCs) seeded on organic or synthetic scaffolds and implanted as hybrid root implants in the jaw bone of minipigs. Immature permanent incisor teeth and unerupted premolars at the early root-forming stage were extracted from three 7-month-old minipigs, and mesenchymal stem/progenitor cells were isolated from dental pulp. Cells were cryopreserved in liquid nitrogen. A year later, new permanent incisor and premolar teeth were extracted; pulp tissue was removed; and pieces of root canals of the extracted teeth, containing collagen or Poly(lactic-co-glycolic acid) scaffolds seeded with the autologous cryopreserved DPSCs, were implanted into the fresh post-extraction socket of the mini pig jaw. The resulting constructs were harvested after 6 and 10 weeks and evaluated by histological and immunohistochemical analyses. Six weeks postoperatively, the central canal space of the root implants showed degrading scaffold material. New extracellular matrix had been deposited in a polar predentin-like pattern on the canal dentinal walls by cuboidal nonpolarized cells. Ten weeks postoperatively, newly formed organic matrix had been consistently deposited on the canal walls. The presence of a continuous layer of polarized cells showing typical columnar morphology adjacent to the newly deposited organic matrix was evident. The interactions of S-DPSCs with the dentin matrix of roots implanted in the jawbone of minipigs constitute a model to study in vivo organization and differentiation potential of DPSCs. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  1. The effects of Mtwo, R-Endo, and D-RaCe retreatment instruments on the incidence of dentinal defects during the removal of root canal filling material.

    PubMed

    Topçuoğlu, Hüseyin Sinan; Demirbuga, Sezer; Tuncay, Öznur; Pala, Kanşad; Arslan, Hakan; Karataş, Ertuğrul

    2014-02-01

    The aim of this study was to compare the incidence of dentinal defects after retreatment procedures with different nickel-titanium rotary retreatment files. One hundred-eighty mandibular premolars were randomly assigned to 6 groups (n = 30 teeth per group). One group was left unprepared, and the remaining 5 groups were prepared with K-files (Dentsply Maillefer, Ballaigues, Switzerland) and filled with gutta-percha and AH plus sealer (Dentsply Maillefer, Ballaigues, Switzerland). Of these 5 groups, 1 group was left filled and received no further treatments; in the other groups, removal of the filling material was performed with Mtwo R (VDW, Munich, Germany), D-RaCe (FKG Dentaire, La Chaux-de-Fonds, Switzerland), R-Endo instruments (Micro-Mega, Besançon, France), or Hedström files (Dentsply Maillefer). Roots were then sectioned 3, 6, and 9 mm from the apex and observed under a microscope. The presence of dentinal defects was noted. Chi-square tests were performed to compare the incidence of dentinal defects between the groups. A Pearson correlation test was performed to check the correlation between defects and root level or remaining dentin thickness. No defects were observed in the unprepared group. Dentinal defects were detected in all retreatment groups. Retreatment groups showed significantly more defects than the filled but no retreatment group (P < .05). There was no significant difference in the occurrence of defects between retreatment groups (P > .05). There was no correlation between the appearance of defects and level of the root or remaining dentin thickness. Under the experimental conditions, all retreatment techniques used in this study created defects in the root dentin. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  2. Influence of Diamond Sono-Abrasion, Air-Abrasion and Er:YAG Laser Irradiation on Bonding of Different Adhesive Systems to Dentin.

    PubMed

    de Oliveira, Marcelo Tavares; de Freitas, Patrícia Moreira; de Paula Eduardo, Carlos; Ambrosano, Glaucia Maria Bovi; Giannini, Marcelo

    2007-07-01

    Different surface treatments may affect bonding performance of adhesive systems to dentin. This study evaluated the influence of different methods of surface treatment on adhesion of bonding agents to dentin. Dentin surfaces abraded with #600-grit SiC paper were used as control. Three methods of surface treatment (sono-abrasion, air-abrasion and Er:YAG laser irradiation) were used under specific parameters. Four adhesive systems (Tyrian, Clearfil SE Bond, Unifil Bond and Single Bond) were applied to treated surfaces, according to the manufacturers' instructions. Composite blocks were built on bonded surfaces, then restored teeth were vertically and serially sectioned to obtain bonded slices for interfacial micromorphologic analysis or to produce beam specimens for mu-TBS bond test. Data were analyzed with two-way ANOVA and Tukey test at a significance level of 5%. The results indicated that the preparation of dentin with sono-abrasion or laser did not affect the bond strength, while the preparation of dentin with SiC paper and air-abrasion influenced the bond strength for some systems. A clear difference of the preparation of dentin surfaces and formation of hybrid layer and resin tags were noted. Bonding effectiveness of both the etch-and-rinse and the self-etch adhesives can be influenced by different methods of dentin preparation.

  3. Influence of Diamond Sono-Abrasion, Air-Abrasion and Er:YAG Laser Irradiation on Bonding of Different Adhesive Systems to Dentin

    PubMed Central

    de Oliveira, Marcelo Tavares; de Freitas, Patrícia Moreira; de Paula Eduardo, Carlos; Ambrosano, Glaucia Maria Bovi; Giannini, Marcelo

    2007-01-01

    Objectives Different surface treatments may affect bonding performance of adhesive systems to dentin. This study evaluated the influence of different methods of surface treatment on adhesion of bonding agents to dentin. Methods Dentin surfaces abraded with #600-grit SiC paper were used as control. Three methods of surface treatment (sono-abrasion, air-abrasion and Er:YAG laser irradiation) were used under specific parameters. Four adhesive systems (Tyrian, Clearfil SE Bond, Unifil Bond and Single Bond) were applied to treated surfaces, according to the manufacturers’ instructions. Composite blocks were built on bonded surfaces, then restored teeth were vertically and serially sectioned to obtain bonded slices for interfacial micromorphologic analysis or to produce beam specimens for μ-TBS bond test. Data were analyzed with two-way ANOVA and Tukey test at a significance level of 5%. Results The results indicated that the preparation of dentin with sono-abrasion or laser did not affect the bond strength, while the preparation of dentin with SiC paper and air-abrasion influenced the bond strength for some systems. A clear difference of the preparation of dentin surfaces and formation of hybrid layer and resin tags were noted. Conclusion Bonding effectiveness of both the etch-and-rinse and the self-etch adhesives can be influenced by different methods of dentin preparation. PMID:19212560

  4. Effect of Intracanal Post Space Treatments on Push-Out Bond Strength of Fiber Posts to Root Dentin

    PubMed Central

    Kermanshah, Hamid; Bolhari, Behnam; Sedaghat, Faraz

    2017-01-01

    Objectives: The main disadvantage of fiber posts is their low bond strength to root canal wall. The aim of the present study was to assess the effect of different root canal post space treatments on push-out bond strength of fiber posts to root canal dentin. Materials and Methods: After post space preparation in 40 endodontically treated human premolars, the teeth were randomly divided into four experimental groups: Group 1: control group, group 2: Endsolv R, group 3: ultrasonic cleaning, group 4: Clearfil Repair. Afterwards, the posts were bonded with Panavia F 2.0 bonding cement. The bond strength of fiber posts to root canal wall in the middle part of canal was evaluated following thermocycling using push-out test. Data were analyzed using one-way ANOVA and Tamhane’s multiple comparisons test. The failure mode of each group was determined under a stereomicroscope. Results: There was a significant difference in the mean push-out bond strength among the groups (P<0.05). The lowest bond strength was noted in the control group. The control group had significant differences with ultrasonic and Clearfil Repair groups (P<0.05). The bond strength of Endsolv R group increased; however, it was not significant (P>0.05). Conclusions: It seems that ultrasonic cleaning and Clearfil Repair can modify the root canal wall and significantly increase the bond strength of fiber posts. PMID:28828018

  5. The Impact of a 940 nm Diode Laser with Radial Firing Tip and Bare End Fiber Tip on Enterococcus faecalis in the Root Canal Wall Dentin of Bovine Teeth: An In Vitro Study.

    PubMed

    Schulte-Lünzum, Ruth; Gutknecht, Norbert; Conrads, Georg; Franzen, Rene

    2017-07-01

    This in vitro study aimed to compare the bactericidal effect of two different laser delivery systems, a radial firing tip (RFT) and bare end fiber tip (BFT) used with the 940 nm diode laser on Enterococcus faecalis inoculated onto bovine radicular dentin. A total of 100 bovine dentin slices with a defined thickness of 500 and 1000 μm were prepared. They were assigned into four test groups together with untreated samples served as control for each slice thickness. The slices were inoculated on one side with 1 μL E. faecalis suspension and laser irradiation was performed indirectly on the opposite side with the 940 nm diode laser delivered with a 200 μm RFT and a BFT at 1 and 1.5 W in continuous wave mode for 8 sec per cycle and repeated four times. After irradiation, the remaining bacteria were detached and the produced suspension was diluted and plated onto blood agar plates with 5% sheep blood and incubated overnight at 37°C in a CO2-rich atmosphere. The colony-forming units of E. faecalis were counted and the bacterial reduction was analyzed. The diode laser equipped with RFT fiber design further reduced the number of vital E. faecalis cells significantly compared with BFT design, regardless of the used power and dentin thickness (p < 0.0001). The highest average value of 4 log kills was observed in 500 μm slice thickness irradiated with RFT at 1.5 W. Temperature measurements on the external root surface at 1 mm from the apex did not elicit a harmful temperature elevation in both power settings and fiber designs. Within the studied parameters, 940 nm diode laser in conjugation with RFT showed a satisfactory bactericidal effect without any thermal side effect to the tooth-supporting tissues.

  6. Effects of NaOCl, EDTA and MTAD when applied to dentine on stress distribution in post-restored roots with flared canals.

    PubMed

    Belli, S; Eraslan, O; Eraslan, O; Eskitascioglu, M; Eskitascioglu, G

    2014-12-01

    To evaluate the effect of NaOCl, EDTA and MTAD on the stress distribution and levels in roots with flared canals and three different aesthetic post systems using finite element stress analysis (FEA). Three-dimensional (3D) FEA models simulating a maxillary incisor with excessive structural loss and flared root canals were created. The dentine of the first models of each post group was assumed as homogenous, whereas the others were deemed as having their elastic modulus affected up to 100 μm deep as a result of irrigation protocol (5.25 NaOCl, 17% EDTA and MTAD for 2 h). A sound incisor tooth model was used as the control. Restorations were created according to the post system used (pre-fabricated fibre post (PFP)), polyethylene fibre (Ribbond) post and core build-up (RBP), and one-piece milled zirconia post and core (ZP). Ceramic crowns were added to the models. A 300-N static load was applied at the centre of the palatal surface of the models to calculate the stress distributions. The SolidWorks/Cosmosworks structural analysis programmes were used for FEA analysis. Results were presented by considering von Mises criteria. The analysis of the von Mises stresses revealed that RBP created less stress in the remaining root dentine when compared to PFP and ZP. ZP maintained the stresses inside its body and reduced stress on the palatal surface of the root; however, it forwarded more stress towards the apical area. NaOCl-, EDTA- and MTAD-treated dentine increased the stresses within the root structure regardless of the effect of the post system used (11-15.4 MPa for PFP, 9.5-13.02 MPa for RBP and 14.2 MPa for ZP). Amongst the irrigation solutions used, EDTA and MTAD increased the stresses more than NaOCl in all models. All the irrigation solutions showed the same stress levels and distributions in the ZP model. NaOCl-, EDTA- and MTAD- treated dentine and a rigid post with high elastic modulus may increase fracture risk in roots with flared canals by increasing the

  7. [Influence of different ultrasonic irrigation solutions after root canal preparation with ProTaper by machine on micro-hardness of root canal dentin].

    PubMed

    Guo, Jiang-li; Zhang, Yan; Zhen, Lei

    2015-08-01

    To develope the influence of different ultrasonic irrigations after root canal preparation with nickel titanium ProTaper on micro-hardness of root canal dentin. Sixty of maxillary anterior teeth with single-canal were collected and randomly divided into 6 groups. Group A was control group, group B was prepared to F3 with nickel titanium ProTaper by machine, group C was ultrasonic irrigated with 3% hydrogen peroxide solution for 1 minute after preparation, group D was ultrasonic irrigated with koutai mouthwash for 1 minute after preparation, group E was ultrasonic irrigated with 17% EDTA solution for 1 minute after preparation, group F was ultrasonic irrigated with distilled water for 1 minute after preparation. The roots were then sectioned horizontally into 3 parts, split longitudinally into halves and examined under a micro Vickers hardness test machine. The data was analyzed by one-way ANOVA and t test with SPSS 17.0 software package. The micro-hardness of group A was (52.66 ± 1.64) HV,(52.08 ± 1.53) HV and (51.47 ± 2.53) HV. There was no significant difference in all parts of the root canal in group A (P>0.05). The micro-hardness of the apical third of root canal was lower than that of the cervical and middle of root canal in the other groups (P<0.05). In the cervical and middle third of the root canals, the micro-hardness of group E was (44.65 ± 1.33) HV and(42.55 ± 1.12) HV, and there were statistical significances between group E and the other groups (P<0.05). In the apical third of root canal,the micro-hardness of group E was (37.82 ± 1.60) HV, and group C was (44.14±1.73) HV, both of the comparative differences with other groups were statistically significant (P<0.05). There was no significant difference among group B, group D and group F (P>0.05). Root canal preparation to F3 with nickel titanium ProTaper by machine can make the micro-hardness of the apical third of root canal decrease. Ultrasonic irrigation with 17% EDTA solution for 1 minute can

  8. Comparison of bond strength of different endodontic sealers to root dentin: An in vitro push-out test

    PubMed Central

    Madhuri, G. Vijaya; Varri, Sujana; Bolla, Nagesh; Mandava, Pragna; Akkala, Lakshmi Swathi; Shaik, Jaheer

    2016-01-01

    Aim: To compare the bond strength of four different endodontic sealers to root dentin through push-out test design. Materials and Methods: Forty single-rooted teeth with completely formed apices were selected. Teeth were decoronated, and working length was determined. Instrumentation and irrigation were performed. The teeth were divided into four groups based upon the sealer used. Group 1: Bioceramic sealer (Endosequence), Group 2: Mineral trioxide aggregate (MTA) based sealer (MTA Fill apex), Group 3: Epoxy resin based sealer (MM-Seal), and Group 4: Dual cure resin-based sealer (Hybrid Root Seal). Manipulation and application of the sealer was done as per the manufacturer instructions. All the teeth were obturated using 6% gutta-percha. After obturation, each tooth was prepared for push-out test with root slices of 2 mm thickness using universal testing machine. Results: The highest bond strength was found in Group 1 (Endosequence) (P < 0.05) compared to other groups. The lowest bond strength was found in Group 2 (MTA Fill apex). Statistical analysis is done by two-way ANOVA and Newman-Keuls multiple post hoc. Conclusion: The push-out bond strength of Bioceramic sealer was highest followed by resin-based sealer and lowest bond strength was observed in MTA-based sealer. PMID:27656067

  9. Comparison of the effects of TripleGates and Gates-Glidden burs on cervical dentin thickness and root canal area by using cone beam computed tomography

    PubMed Central

    SOUSA, Kássio; ANDRADE-JUNIOR, Carlos Vieira; da SILVA, Juliana Melo; DUARTE, Marco Antonio Hungaro; DE-DEUS, Gustavo; da SILVA, Emmanuel João Nogueira Leal

    2015-01-01

    The search for new instruments to promote an appropriate cervical preparation has led to the development of new rotary instruments such as TripleGates. However, to the best of the authors' knowledge, there is no study evaluating TripleGates effect on the “risk zone” of mandibular molars. Objectives : The aim of this study was to evaluate the effects of a crown-down sequence of Gates-Glidden and TripleGates burs on the remaining cervical dentin thickness and the total amount of dentin removed from the root canals during the instrumentation by using cone beam computed tomography. The number of separated instruments was also evaluated. Material and Methods : Mesial roots of 40 mandibular first molars were divided into 2 equal groups: crown-down sequence of Gates-Glidden (#3, #2, #1) and TripleGates burs. Cervical dentin thickness and canal area were measured before and after instrumentation by using cone beam computed tomography and image analysis software. Student’s t-test was used to determine significant differences at p<0.05. Results : No significant differences (p>0.05) were observed between the instruments, regarding the root canal area and dentin wall thickness. Conclusion : Both tested instruments used for cervical preparation were safe to be used in the mesial root canal of mandibular molars. PMID:26018308

  10. Evaluation of the tensile bond strength of an adhesive system self-etching in dentin irradiated with Er:YAG laser

    NASA Astrophysics Data System (ADS)

    de Mello, Andrea M. D.; Mello, Fabiano A. S.; Matson, Edmir; Mattos, Adriana B.; Mello, Guilerme S.

    2001-04-01

    Since Buonocore, several researchers have been seeking for the best adhesive system and treatment for the enamel and dentin surfaces. The use of the acid has been presented as one of the best techniques of dentin conditioning, because this promotes the removal of the 'smear layer' and exhibition of dentinal structure, for a best penetration and micro-retention of the adhesive system. However, some conditioning methods have been appearing in the literature, for the substitution or interaction with the acid substances, as the laser. The objective of this work is to evaluate the tensile bond strength of the adhesive system 'self-etching' associated to a composed resin, in dentin surfaces conditioned with the Er:YAG laser. For this study, freshly extracted human teeth were used and in each one the dentinal surfaces, which were treated with three sandpapers of different granulations to obtain a standard of the smear layer, before the irradiation of the laser and of the restoring procedure. After these procedures the specimens were storage in distilled water at 37 degrees for 24 hours. Soon after, they were submitted to the tensile strength test. After analyzing the results, we can conclude that the use of the Er:YAG laser can substitute the drill without the need of conditioning, when using the adhesive system 'self etching' in the dentinal surfaces because there was a decline in the strength of adhesion in the groups conditioned with the laser.

  11. The Influence of Dentine on the pH of Calcium Hydroxide, Chlorhexidine Gel, and Experimental Bioactive Glass-Based Root Canal Medicament

    PubMed Central

    Nunes Carvalho, Ceci; Gonzales Freire, Laila; Pinheiro Lima de Carvalho, Alexandre; Luiz Siqueira, Evandro; Bauer, José; Cunha Gritti, Giovana; Pereira de Souza, Juliana; Gavini, Giulio

    2015-01-01

    Objectives. To evaluate the influence of dentine on the pH of different medications in standardized simulated canals. Materials and Methods. Forty resin blocks were divided into groups with and without dentine powder, as follows: 2% chlorhexidine gel; 2% chlorhexidine gel associated with calcium hydroxide PA; calcium hydroxide PA delivered in propylene glycol 600; and NPG delivered in distilled water. The dentine powder was obtained from the root dentine of bovine teeth and added to the medications. The simulated canals were placed in containers with 1.5 mL of deionized water and pH was monitored in multiple intervals, up to 30 days. The mean pH values were calculated and submitted to statistical analysis using paired Student's t-test and ANOVA complemented by the Tukey test (p < 0.05). Results. There was no statistical difference between the groups with and without dentine powder (p > 0.05). The pH values of calcium hydroxide were significantly higher than those of NPG in the first 24 hours (p < 0.05). After 7 days, both behaved in a similar manner. Conclusion. The addition of dentine powder to the medications evaluated did not alter the pH of the external solution in any of the time points tested. PMID:26347249

  12. Effect of titanium dioxide and 3.5% hydrogen peroxide with 405-nm diode laser irradiation on bonding of resin to pulp chamber dentin

    NASA Astrophysics Data System (ADS)

    Haruyama, A.; Kato, J.; Kameyama, A.; Hirai, Y.; Oda, Y.

    2010-04-01

    This study was conducted to determine the effect of a 3.5% hydrogen peroxide solution containing titanium dioxide on bonding of resin to pulp chamber dentin. Extracted bovine anterior teeth were allocated to three groups of ten teeth each. The coronal labial pulp chamber dentin was exposed and bleached with 3.5% hydrogen peroxide with titanium dioxide with 405-nm diode laser irradiation for 15 min (Group 1); 30% hydrogen peroxide with halogen lamp irradiation for 15 min (Group 2); and distilled water for 15 min (Group 3). After bleaching, the pulp chamber dentin was prepared for composite resin bonding and the interface between the resin and dentin was observed by scanning electron microscopy. The microtensile bond strength (μTBS) and failure patterns were determined. The μTBS values (mean ± SD) were: 17.28 ± 5.79 MPa ( n = 36), 0 MPa, and 26.50 ± 9.83 MPa ( n = 36) in Groups 1, 2, and 3, respectively. The μTBS in Group 3 was significantly higher than that in Group 1 ( P < 0.05). Hybrid layers and resin tags were clearly observed at the interface in Groups 1 and 3, but not in Group 2. Adhesive failure was mainly observed in Group 1, whereas dentin failure was the main failure pattern in Group 3.

  13. Occurrence of Dentinal Microcracks in Severely Curved Root Canals with ProTaper Universal, WaveOne, and ProTaper Next File Systems.

    PubMed

    Li, Shu-hui; Lu, Ying; Song, Dongzhe; Zhou, Xuedong; Zheng, Qing-hua; Gao, Yuan; Huang, Ding-ming

    2015-11-01

    This study aims to compare the incidence of dentinal microcracks produced by the ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland), WaveOne (Dentsply Maillefer), and ProTaper Next (Dentsply Maillefer) file systems during root canal procedures in severely curved canals using a dyeing technique. Sixty extracted human molars with 25° to 40° root curvatures were divided into 3 groups of 20 canals each. ProTaper Universal, WaveOne, and ProTaper Next file systems were used for root canal procedures. Untreated root canals of 60 molars served as negative controls. After preparation, all roots were stained with 1% methylene blue for 24 hours. Roots were then sectioned at the most curved plane and 2 mm below and above the most curved plane with a low-speed saw under cold water. A stereomicroscope was used to inspect dentinal microcracks at 60× magnification, and differences between these 3 instrument groups were analyzed using the chi-square test. The ProTaper Next system induced less complete and incomplete dentinal microcracks compared with the ProTaper Universal and WaveOne systems (P < .05), and there were no significant differences between the ProTaper Universal and WaveOne systems (P > .05). The ProTaper Universal and WaveOne systems induced significantly more complete cracks in the plane 2 mm above the most curved plane compared with either of the other 2 planes (P = .004). The ProTaper Next system induces less dentinal microcracks during root canal procedures in severely curved root canals compared with the ProTaper Universal and WaveOne systems. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  14. The effect of EDTA, EGTA, EDTAC, and tetracycline-HCl with and without subsequent NaOCl treatment on the microhardness of root canal dentin.

    PubMed

    Sayin, Taner Cem; Serper, Ahmet; Cehreli, Zafer C; Otlu, Harika G

    2007-09-01

    The purpose of this study was to evaluate the effect of single and combined use of ethylenediamine tetra acetic acid (EDTA), ethylene glycol bis [b-aminoethylether] N,N,N',N'-tetraacetic acid (EGTA), EDTA plus Cetavlon (EDTAC), tetracycline-HCl, and NaOCl on the microhardness of root canal dentin. The crowns of 30 single-rooted human teeth were discarded at the cementoenamel junction and the roots were bisected longitudinally to obtain root halves (N = 60). The specimens were embedded in autopolymerizing acrylic resin, leaving the root canal dentin exposed. Dentin surfaces were prepared for microhardness test by grinding and polishing. The reference microhardness values of untreated specimens were recorded using a Vicker's microhardness tester at the apical, midroot, and cervical levels of the root canal. Thereafter, the specimens treated with single (test solution only) or combined (test solution, followed by 2.5% NaOCl) versions of the irrigants for 5 minutes. Posttreatment microhardness values were obtained as with initial ones. Statistical comparisons between the test groups and among single and combined treatments were carried out using 2-way ANOVA with repeated measures (P =.05). Comparisons within each group with respect to application regions were made with Friedman's nonparametric 2-way analysis of variance at the same level of significance. All treatment regimens except distilled water significantly decreased the microhardness of the root canal dentin (P < . 05). The single and combined use of EDTA decreased the microhardness of the root canal dentin significantly more than all other treatment regimens (P < .05). Compared with their single-treatment versions, all combined treatment regimens decreased the mean microhardness values significantly (P < .05). A comparison of single and combined treatment regimens revealed significant decreases only for EDTA and EDTA + NaOCl in the coronal region and for EDTAC and EDTAC + NaOCl in the apical and middle regions

  15. Fracture Forces of Dentin after Surface Treatment with High Speed Drill Compared to Er:YAG and Er,Cr:YSGG Laser Irradiation

    PubMed Central

    Franzen, Rene; Kianimanesh, Nasrin; Marx, Rudolf; Ahmed, Asma; Gutknecht, Norbert

    2016-01-01

    Dental tooth restorative procedures may weaken the structural integrity of the tooth, with the possibility of leading to fracture. In this study we present findings of coronal dentin strength after different techniques of surface modification. The fracture strength of dentin beams after superficial material removal with a fine diamond bur high speed drill hand piece, Er:YAG (2.94 μm, 8 J/cm2), and Er,Cr:YSGG (2.78 μm, 7.8 J/cm2) laser irradiation slightly above the ablation threshold was measured by a four-point bending apparatus. Untreated dentin beams served as a control. A total of 58 dentin beams were manufactured from sterilized human extracted molars using the coronal part of the available dentin. Mean values of fracture strength were calculated as 82.0 ± 27.3 MPa for the control group (n = 10), 104.5 ± 26.3 MPa for high speed drill treatment (n = 10), 96.1 ± 28.1 MPa for Er,Cr:YSGG laser irradiation (n = 20), and 89.1 ± 36.3 MPa for Er:YAG laser irradiation (n = 18). Independent Student's t-tests showed no significant difference between each two groups (p > 0.05). Within the parameter settings and the limits of the experimental setup used in this study, both lasers systems as well as the high speed drill do not significantly weaken coronal dentin after surface treatment. PMID:26962473

  16. Effect of gamma irradiation on microbiological, chemical and sensory characteristics of licorice root product

    NASA Astrophysics Data System (ADS)

    Al-Bachir, M.; Al-Adawi, M. A.; Al-Kaid, A.

    2004-03-01

    Licorice root products were irradiated at doses of 0, 5, 10, 15 and 20 kGy in a 60Co package irradiator. Irradiated and unirradiated samples were stored at room temperatures. Microbial population on product, chemical changes and sensory properties of produced solution of licorice root products were evaluated after 0 and 12 months of storage. The results indicated that gamma irradiation reduced the counts of microorganisms on licorice root products. D10 of total count and klebsiella spp. were about 1.4 and 0.7 kGy, respectively. The mineral ions (Na, Ca and K) concentration in solution produced from irradiated products were lower than non-irradiated ones. Glycyrrhezinic acid and maltose concentration in solution produced from irradiated products were higher than non-irradiated ones. Sensory evaluation indicated that no significant differences ( P<0.05) were found between solution produced from irradiated and unirradiated products in color, flavor, texture, or taste.

  17. Analysis of peripheral thermal damage after laser irradiation of dentin using polarized light microscopy and synchrotron radiation infrared spectromicroscopy

    NASA Astrophysics Data System (ADS)

    Dela Rosa, Alfredo; Sarma, Anupama V.; Le, Charles Q.; Jones, Robert S.; Fried, Daniel

    2004-05-01

    It is necessary to minimize peripheral thermal damage during laser irradiation, since thermal damage to collagen and mineral compromises the bond strength to restorative materials in dentin and inhibits healing and osteointegration in bone. The overall objective of this study was to test the hypothesis that lasers resonant to the specific absorption of water, collagen, and hydroxyapatite with pulse durations less than the thermal relaxation times at each respective laser wavelength will efficiently remove dentin with minimal peripheral thermal damage. Precise incisions were produced in 3 x 3 mm2 blocks of human dentin using CO2 (9.6 μm), Er:YSGG (2.79 μm), and Nd:YAG (355 nm) lasers with and without a computer controlled water spray. Polarization-sensitive optical coherence tomography was used to obtain optical cross-sections of each incision to determine the rate and efficiency of ablation. The peripheral thermal damage zone around each incision was analyzed using polarized light microscopy (PLM) and Synchrotron-Radiation Fourier Transform Infrared Spectro-microscopy (SR-FTIR). Thermally induced chemical changes to both mineral and the collagen matrix was observed with SR-FTIR with a 10-μm spatial resolution and those changes were correlated with optical changes observed with PLM. Minimal (<10-μm) thermal damage was observed for pulse durations less than the thermal relaxation time (Tr ) of the deposited laser energy, with and without applied water at 9.6 um and only with applied water at 2.79 μm. For pulse durations greater than Tr, significantly greater peripheral thermal damage was observed for both IR laser wavelengths with and without the water spray. There was minimal thermal damage for 355-nm laser pulses, however extensive mechanical damage (cracks) was observed. High resolution SR-FTIR is well suited for characterization of the chemical changes that occur due to thermal damage peripheral to laser incisions in proteinaceous hard tissues. Sub

  18. Effect of superoxidized water and sodium hypochlorite, associated or not with EDTA, on organic and inorganic components of bovine root dentin.

    PubMed

    Ghisi, Alexandre Corrêa; Kopper, Patrícia Maria Poli; Baldasso, Flávia E R; Stürmer, Caroline P; Rossi-Fedele, Giampiero; Steier, Liviu; de Figueiredo, José Antonio Poli; Morgental, Renata Dornelles; Vier-Pelisser, Fabiana Vieira

    2015-06-01

    This study aimed to evaluate the effects of Sterilox (Sx), a superoxidized water, 5% and 2% sodium hypochlorite (5NaOCl and 2NaOCl), and 17% EDTA (E) on the organic and inorganic components of bovine dentin. Eighty bovine incisors were randomly divided into 8 groups (n = 10): 5NaOCl, 5NaOCl + E, 2NaOCl, 2NaOCl + E, Sx, Sx + E, E alone, and distilled water (H2O). Root canal instrumentation was performed by using the corresponding irrigant. The apical 15 mm was longitudinally sectioned into 2 fragments, one for light microscopy analysis in slides stained with picrosirius red (organic component) and the other for scanning electron microscopy analysis (inorganic component). Scores data obtained in the light microscopy analysis were submitted to the Kruskal-Wallis test, followed by multiple comparisons test (P < .05). Scanning electron microscopy images were analyzed descriptively. The chemical solution 5NaOCl had a greater effect on the organic component of dentin in area and depth than 2NaOCl. The chemical solutions 5NaOCl + E, 5NaOCl and 2NaOCl + E caused the greatest change in the collagenous organic matrix near the root canal lumen. The chemical solution 2NaOCl showed similar behavior to Sx, associated or not with E, promoting more superficial disorganization of collagen in a smaller area. Demineralization was observed in all groups in which E was used. However, areas of erosion and open dentinal tubules were detected only when it was combined with NaOCl. Five percent NaOCl promoted the most extensive damage to the organic component of dentin, and when associated to EDTA, dentinal erosion could be seen. Considering these specific aspects, 2% NaOCl and Sx had milder effects on bovine root dentin. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  19. Adhesives bonded to erbium:yttrium-aluminum-garnet laser-irradiated dentin: transmission electron microscopy, scanning electron microscopy and tensile bond strength analyses.

    PubMed

    Ramos, Andreia Cristina Bastos; Esteves-Oliveira, Marcella; Arana-Chavez, Victor E; de Paula Eduardo, Carlos

    2010-03-01

    The aim of this in vitro study was to investigate the effect of erbium:yttrium-aluminum-garnet (Er:YAG) laser irradiation on dentinal collagen by transmission electron microscopy and to analyze the resin-dentin interface by scanning electron microscopy. A tensile bond strength test was also applied. Specimens from 69 sound human third molars were randomly divided into three groups: control (no laser), and two irradiated groups, laser 250 (250 mJ/2 Hz) and laser 400 (400 mJ/4 Hz). Then, specimens were restored with two adhesive systems, an etch-and-rinse or a self-etch system. Although ultrastructural examination showed a modified surface in the irradiated dentin, there was no statistical difference in bond strength values between the laser groups and controls (P < 0.05). In conclusion, the use of Er:YAG laser for ablating human dentin did not alter the main adhesion parameters when compared with those obtained by conventional methods, thus reinforcing its use in restorative dentistry.

  20. The evaluation of displacement resistance of glass FRC posts to root dentine using a thin slice push-out test.

    PubMed

    Toman, M; Toksavul, S; Sarikanat, M; Firidinoğlu, K; Akin, A

    2009-09-01

    To investigate and compare the displacement resistance of glass fibre reinforced composite (FRC) posts to root dentine after luting with different adhesive systems. A total of 32 noncarious extracted human mandibular premolars were prepared for post-cementation using the FRC Postec system (Ivoclar Vivadent, Schaan, Liechtenstein) and divided into four groups (n = 8). The posts in each group were luted with one or other of the following materials. Group 1: Variolink II/Excite DSC (etch-and-rinse, dual-curing), group 2: Clearfil Esthetic Cement/ED Primer II (self-etch, dual-curing), group 3: Multilink/Multilink Primer (self-etch, chemical-curing) and group 4: Multilink Sprint (self-adhesive, dual-curing). Specimens were sectioned to obtain slices with the post in the centre and with the root dentine overlaid by the autopolymerizing acrylic resin on each side. The displacement resistance was measured using a Universal Testing Machine at a crosshead speed of 0.5 mm min(-1). The displacement resistance of the specimens were calculated and expressed in MPa. Data were analysed with one-way ANOVA and post hoc Tukey's test (P < 0.05). Mean (SD) values of displacement resistance data in MPa are as follows: group 1, 12.08 (2.13); group 2, 12.39 (2); group 3, 11.3 (1.23); group 4, 14.29 (1.84). There were statistically significant differences amongst the groups (P = 0.021). A statistically significant difference was observed for the displacement resistance values between groups 3 and 4 (P = 0.015), that is between Multilink/Multilink Primer and Multilink Sprint. Glass FRC posts luted with self-adhesive luting system exhibited higher displacement resistance than when luted with chemical-curing self-etch luting system.

  1. Microbial biofilm proliferation within sealer-root dentin interfaces is affected by sealer type and aging period

    PubMed Central

    Roth, Karina A; Friedman, Shimon; Lévesque, Céline M; Basrani, Bettina R; Finer, Yoav

    2012-01-01

    Background Root canal fillings are intended to prevent microbial proliferation over time in the canal after treatment. Objective To assess biofilm proliferation within the sealer-dentin interfaces of two methacrylate resin-based systems, self-etch (SE) and total-etch (TE), and an epoxy resin-based sealer (EP), aged for up to 6 months. Methods Standardized specimens (n=45) comprising the coronal 5 mm of human roots were filled with the test materials and gutta-percha. Specimens were either not pre-incubated (control; n=9), or incubated in sterile saline for 1 week, 1 month, 3 months or 6 months (n=3/group). Monospecies biofilms of Enterococcus faecalis were grown on the specimens for 7 days in a chemostat-based biofilm fermentor mimicking pathogenic oral conditions. The extent of E. faecalis proliferation within the sealer-dentin interface for each material and incubation period group was assessed using fluorescence microscopy of dihydroethidium-stained specimens. Results TE had less biofilm proliferation than both EP and SE (p<0.01). Deeper biofilm proliferation was detected in SE and EP specimens aged for 1 and 3 months than those aged for 1 week or 6 months (p<0.05). Maximum depth of biofilm penetration was recorded for SE at 1 month (p<0.05). Conclusion Within the test model used, the self-etch and epoxy resin-based sealers were more susceptible to interfacial biofilm proliferation than the total-etch restorative material. This susceptibility diminished after aging the materials’ interfaces for 6 months. PMID:22892745

  2. Effect of Resin Cement Pre-heating on the Push-out Bond Strength of Fiber Post to Root Canal Dentin

    PubMed Central

    Alizadeh Oskoee, Parnian; Nooroloyouni, Ahmad; Pornaghi Azar, Fatemeh; Sajjadi Oskoee, Jafar; Pirzadeh Ashraf, Ahmad

    2015-01-01

    Background and aims. Various factors influence the interfacial bond between the fiber posts and root canal dentin. The aim of the present study was to evaluate the effect of pre-warming of resin cement on the push-out bond strength of fiber posts to various segments of root canal dentin. Materials and methods. In this in vitro study, 40 single-rooted human premolars were decoronated and underwent root canal treatment along with post space preparation. The samples were randomly divided into two groups: In group 1, Panavia F 2.0 cement was used at room temperature; in group 2, the same cement was warmed to 55‒60°C before mixing. After fiber posts were placed and cemented in the root canals, 3 dentin/post sections (coronal, middle and apical) with a thickness of 3 mm were prepared. A universal testing machine was used to measure push-out bond strength in MPa. Data was analyzed using two-factor ANOVA and a post hoc Tukey test at α=0.05. Results. The mean value of push-out bond strength was high at room temperature, and the differences in the means of push-out bond strength values between the resin cement temperatures and between different root segments in each temperature were significant (P<0.05). Conclusion. Pre-warming of Panavia F 2.0 resin cement up to 55-60°C reduced push-out bond strength to root canal dentin. In addition, in each temperature group bond strengths decreased from coronal to apical segments. PMID:26889360

  3. Adhesion to root canal dentine using one and two-step adhesives with dual-cure composite core materials.

    PubMed

    Foxton, R M; Nakajima, M; Tagami, J; Miura, H

    2005-02-01

    The regional tensile bond strengths of two dual-cure composite resin core materials to root canal dentine using either a one or two-step self-etching adhesive were evaluated. Extracted premolar teeth were decoronated and their root canals prepared to a depth of 8 mm and a width of 1.4 mm. In one group, a one-step self-etching adhesive (Unifil Self-etching Bond) was applied to the walls of the post-space and light-cured for 10 s. After which, the post-spaces were filled with the a dual-cure composite resin (Unifil Core) and then half the specimens were light-cured for 60 s and the other half placed in darkness for 30 min. In the second group, a self-etching primer (ED Primer II) was applied for 30 s, followed by an adhesive resin (Clearfil Photo Bond), which was light-cured for 10 s. The post-spaces were filled with a dual-cure composite resin (DC Core) and then half the specimens were light-cured for 60 s and the other half placed in darkness for 30 min. Chemical-cure composite resin was placed on the outer surfaces of all the roots, which were then stored in water for 24 h. They were serially sliced perpendicular to the bonded interface into 8, 0.6 mm-thick slabs, and then transversely sectioned into beams, approximately 8 x 0.6 x 0.6 mm, for the microtensile bond strength test (muTBS). Data were divided into two (coronal/apical half of post-space) and analysed using three-way anova and Scheffe's test (P < 0.05). Failure modes were observed under an scanning electron microscope (SEM) and statistically analysed. Specimens for observation of the bonded interfaces were prepared in a similar manner as for bond strength testing, cut in half and embedded in epoxy resin. They were then polished to a high gloss, gold sputter coated, and after argon ion etching, observed under an SEM. For both dual-cure composite resins and curing strategies, there were no significant differences in muTBS between the coronal and apical regions (P > 0.05). In addition, both dual

  4. Application of resin adhesive on the surface of a silanized glass fiber-reinforced post and its effect on the retention to root dentin.

    PubMed

    Machado, Fernanda Weingartner; Bossardi, Mayara; Ramos, Tatiana dos Santos; Valente, Lisia Lorea; Münchow, Eliseu Aldrighi; Piva, Evandro

    2015-01-01

    In this study, the effect of different post surface treatments on the retention of glass fiber-reinforced post to root dentin was evaluated. The hypotheses tested were (1) post silanization would not improve its retention and (2) the application of silane plus resin adhesive on the post would enhance its retention. After root canal preparation, 4 different protocols (n = 5) of post surface treatment were evaluated, combined with or without silane (Silane coupling agent) and adhesive (Scotchbond Multipurpose): silane + adhesive (S/A), only silane, only adhesive, or no treatment (control). RelyX ARC was used for post cementation. Next, specimens were subjected to push-out bond strength testing, and data were analyzed by two-way analysis of variance and Tukey test (P < .05). S/A showed higher bond strength than other protocols in the middle and coronal root regions (P < .001). Only silane did not enhance post retention compared with control (P > .05). The root dentin region influenced bond strength results only in the S/A group. Whereas silanization as the only post surface treatment did not improve retention, the combination of silane plus resin adhesive enhanced post retention to dentin in the middle and coronal root regions. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. Effects of two combinations of triple antibiotic paste used in endodontic regeneration on root microhardness and chemical structure of radicular dentine.

    PubMed

    Prather, Blake T; Ehrlich, Ygal; Spolnik, Kenneth; Platt, Jeffrey A; Yassen, Ghaeth H

    2014-12-01

    We investigated the effects of triple antibiotic paste (TAP) and modified triple antibiotic paste (MTAP) concentrations on the microhardness and chemical structure of radicular dentine. Human root cylinders were instrumented and randomized into four treatment groups and an untreated control group. Two treatment groups received 1 g/mL TAP or MTAP, and the other two treatment groups received 1 mg/mL methylcellulose-based TAP or MTAP. Cylinders were stored at 100% relative humidity for 4 weeks. Each root cylinder was subjected to a microhardness test before and after treatment. Different sets of radicular dentine specimens were treated as mentioned previously, and were examined using attenuated total reflection Fourier transform infrared spectroscopy. All treatment groups showed significant reductions in microhardness of roots when compared to untreated control roots at 1,000 and/or 500 µm from the pulp-dentine interface. However, 1 mg/mL methylcellulose-based antibiotics caused significantly less reduction in microhardness when compared to 1 g/mL antibiotics. In addition, 1 g/mL TAP and DAP caused significantly lower phosphate/amide I ratios when compared to other groups. The use of 1 mg/mL methylcellulose-based TAP and MTAP may minimize the reduction in microhardness of roots compared with the currently used 1 g/mL concentration of these antibiotics.

  6. Long-term chlorhexidine effect on bond strength to Er:YAG laser irradiated-dentin.

    PubMed

    Galafassi, Daniel; Scatena, Camila; Colucci, Vivian; Rodrigues-Júnior, Antonio Luiz; Campos Serra, Mônica; Corona, Silmara Aparecida Milori

    2014-01-01

    This study evaluates the bond strength of dentin prepared with Er:YAG laser or bur, after rewetting with chlorhexidine on long-term artificial saliva storage and thermocycling. One hundred and twenty human third molars were sectioned in order to expose the dentin surface (n = 10). The specimens were randomly divided in 12 groups according to treatment and aging: Er:YAG laser rewetting with deionized water (LW) and 24 h storage in artificial saliva (WC); LW and 6 months of artificial saliva storage + 12.000 thermocycling (6M), LW and 12 months of artificial saliva storage + 24.000 thermocycling (12M), Er:YAG laser rewetting with 2% chlorhexidine (LC) and WC, LC and 6M, LC and 12M, bur on high-speed turbine rewetting with deionized water (TW) and WC, TW6M, TW12M, bur on high-speed turbine + 2% chlorhexidine (TC) and WC, TC and 6M, TC and 12M. The specimens were etched with 35% phosphoric acid, washed, and dried with air. Single Bond 2 adhesive was applied and the samples were restored with a composite. Each tooth was sectioned in order to obtain 4 sticks, which were submitted to microtensile bond strength test (µTBS). The two-way ANOVA, showed no significant differences for the interaction between the factors and for the aging factor. Tukey 5% showed that the LC group had the lowest µTBS. The rewetting with chlorhexidine negatively influenced the bond strength of the preparation with the Er:YAG laser. The artificial saliva aging and thermocycling did not interfere with dentin bond strength.

  7. "Dentinal microcracks after root canal preparation" a comparative evaluation with hand, rotary and reciprocating instrumentation.

    PubMed

    Priya, N Tulasi; Chandrasekhar, Veeramachaneni; Anita, S; Tummala, Muralidhar; Raj, T B Phanindhar; Badami, Vijetha; Kumar, Pradeep; Soujanya, E

    2014-12-01

    The purpose of this study was to compare the incidence of dentinal micro cracks after instrumentation with various types of NiTi files in rotary and reciprocating motion. One hundred human extracted mandibular central incisors were taken and divided into 10 groups (n=10 teeth per group). Group 1- No preparation, Group 2 - Hand instrumentation, Groups 3,4 - ProTaper files in rotary and reciprocating motion, Groups 5,6 - ProTaper Next files in rotary and reciprocating motion, Groups 7,8 - Oneshape files in rotary and reciprocating motion, Groups 9,10 - Reciproc files in rotary and reciprocating motion. Specimens were sectioned horizontally at 3,6 and 9 mm from the apex and dentinal micro cracks were observed under a stereomicroscope. There was a statistically significant difference between the groups (p<0.05). There were no significant differences in crack formation between the groups (Protaper Next - Rot, Protaper Next - Rec, Reciproc - Rec); (ProTaper - Rot, ProTaper - Rec, Oneshape - Rot), (Oneshape - Rot, Reciproc - Rot), (One shape Reciproc, Reciproc - Rec); (p >.05). Least cracks were seen in canals instrumented with Pro Taper Next files both in rotary and reciprocating motion. Full sequence rotary systems showed less cracks than single file systems and full sequence rotary systems showed less cracks in reciprocating motion than in rotary motion.

  8. Micro-computed Tomography Assessment of Dentinal Micro-cracks after Root Canal Preparation with TRUShape and Self-adjusting File Systems.

    PubMed

    Zuolo, Mario Luis; De-Deus, Gustavo; Belladonna, Felipe Gonçalves; Silva, Emmanuel João Nogueira Leal da; Lopes, Ricardo Tadeu; Souza, Erick Miranda; Versiani, Marco Aurélio; Zaia, Alexandre Augusto

    2017-04-01

    The aim of the present study was to evaluate the percentage frequency of dentinal micro-cracks observed after root canal preparation with TRUShape and Self-Adjusting File (SAF) systems by means of micro-computed tomography imaging analysis. A conventional full-sequence rotary system (BioRace) and a single-file reciprocation system (Reciproc) were used as reference techniques for comparison because of their known assertive cutting efficiency. Forty anatomically matched mandibular incisors were selected, scanned at a resolution of 14.25 μm, and assigned to 4 experimental groups (n = 10), according to the preparation protocol: TRUShape, SAF, BioRace, and Reciproc systems. After the experimental procedures, the specimens were scanned again, and the registered preoperative and postoperative cross-section images of the roots (n = 70,030) were screened to identify the presence of dentinal micro-cracks. Overall, dentinal defects were observed in 28,790 cross-section images (41.11%). In the TRUShape, SAF, BioRace, and Reciproc groups, dentinal micro-cracks were visualized in 56.47% (n = 9842), 42.38% (n = 7450), 32.90% (n = 5826), and 32.77% (n = 5672) of the slices, respectively. All dentinal defects observed in the postoperative data sets were already present in the corresponding preoperative images. None of the preparation systems induced the formation of new dentinal micro-cracks. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  9. Evaluation of Root Canal Dentin Erosion after Different Irrigation Methods Using Energy-dispersive X-ray Spectroscopy.

    PubMed

    Wang, Zhejun; Maezono, Hazuki; Shen, Ya; Haapasalo, Markus

    2016-12-01

    The purpose of this study was to examine the level of erosion in root dentin caused by different irrigation methods and protocols. Thirty-five extracted upper molar teeth were instrumented and divided into 7 groups to undergo treatment by different methods: negative control, GentleWave System (Sonendo Inc, Laguna Hills, CA), and syringe needle irrigation following different protocols. The teeth were instrumented to size #25/.08 or #30/.09 for needle irrigation groups and to ProTaper size S1 for the GentleWave group under 5% sodium hypochlorite (NaOCl). The needle irrigation groups were subjected to final rinses of 2 minutes of 3% NaOCl + 2 minutes of 8% EDTA (3% N2 + 8% E2), 2 minutes of 3% NaOCl + 2 minutes of 8% EDTA + 1 minute of 3% NaOCl (3% N2 + 8% E2 + 3% N1), 2 minutes of 5% NaOCl + 2 minutes of 17% EDTA (5% N2 + 17% E2), 2 minutes of 5% NaOCl + 2 minutes of 17% EDTA + 1 minute of 5% NaOCl (5% N2 + 17% E2 + 5% N1), and 5 minutes of 5% NaOCl + 5 minutes of 17% EDTA + 5 minutes of 5% NaOCl (5% N5 + 17% E5 + 5% N5), respectively. The root canal surface was observed by scanning electron microscopy, and the dentin composition was analyzed by continuous line scanning for 300 μm into dentin using energy-dispersive X-ray spectroscopy. A slight but statistically significant decrease of calcium and an increase of carbon was measured in the 5% N2 + 17% E2 group in comparison with the control; no significant difference was found among GentleWave, 3% N2 + 8% E2, and 5% N2 + 17% E2 (P > .05). A final 1-minute rinse with 3% or 5% NaOCl reduced calcium and phosphorus to a significantly lower level than in groups without a 1-minute final rinse (P < .05). Final irrigation with 5% NaOCl for 5 minutes removed almost all calcium and phosphorus. Scanning electron microscopy showed canal wall erosion when an additional final irrigation with NaOCl was done. NaOCl followed by final EDTA irrigation performed either by syringe needle or the Gentle

  10. Effect of calcium hydroxide and double and triple antibiotic pastes on the bond strength of epoxy resin-based sealer to root canal dentin.

    PubMed

    Akcay, Merve; Arslan, Hakan; Topcuoglu, Hüseyin Sinan; Tuncay, Oznur

    2014-10-01

    The aim of this study was to evaluate the effects of calcium hydroxide (CH) and triple (TAP) and double (DAP) antibiotic pastes on the bond strength of an epoxy resin-based sealer (AH Plus Jet; Dentsply DeTrey, Konstanz, Germany) to the root canal dentin. Sixty-four single-rooted human mandibular premolars were decoronated and prepared using the rotary system to size 40. The specimens were randomly divided into a control group (without intracanal dressing) and 3 experimental groups that received an intracanal dressing with either CH, DAP, or TAP (n = 16). The intracanal dressing was removed by rinsing with 10 mL 17% EDTA followed by 10 mL 2.5% sodium hypochlorite. The root canals were then obturated with gutta-percha and AH Plus Jet sealer. A push-out test was used to measure the bond strength between the root canal dentin and the sealer. The data were analyzed using 2-way analysis of variance and Tukey post hoc tests to detect the effect of the independent variables (intracanal medicaments and root canal thirds) and their interactions on the push-out bond strength of the root canal filling material to the root dentin (P = .05). The push-out bond strength values were significantly affected by the intracanal medicaments (P < .001) but not by the root canal thirds (P > .05). In the middle and apical third, the bond strength of the TAP group was higher than those of the CH and DAP groups (P < .05). The DAP and CH did not affect the bond strength of the epoxy resin-based sealer. Additionally, the TAP improved the bond strength of the epoxy resin-based sealer in the middle and apical thirds. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  11. Quantitive evaluation of dentin sialoprotein (DSP) using microbeads - a potential early marker of root resorption.

    PubMed

    Lombardo, L; Carinci, F; Martini, M; Gemmati, D; Nardone, M; Siciliani, G

    2016-01-01

    This study had the aim of comparing two different methods of analysing dentin sialoprotein (DSP) in the gingival crevicular fluid (GCF): the conventional eLISA approach and a new method involving the use of magnetic micro-beads coated with an antibody specific for DSP prior to eLISA analysis. GCF was taken from six patients following twelve weeks of orthodontic treatment using paper strips inserted into the mesial and distal sulci of the upper incisors, and analysed using both methods. Statistical analysis of the results using the Mann-Whitney non-parametric test showed that the micro-bead approach conferred more reliability and less variability on the conventional eLISA approach. Furthermore, this method, for the first time, enables the quantification of the DSP in the sample in ng/μl. The innovative micro-bead/eLISA approach proposed provides a reliable means of quantifying the DSP in the GCF.

  12. Influence of powder composition and morphology on penetration of gray and white ProRoot mineral trioxide aggregate and calcium hydroxide into dentin tubules

    PubMed Central

    Komabayashi, Takashi; Long, Leann; Ahn, Chul; Spears, Robert; Zhu, Qiang; Eberhart, Robert C.

    2015-01-01

    This study examined the influence of powder composition and morphology on the penetration of Gray and White ProRoot mineral trioxide aggregate (GMTA, WMTA) and calcium hydroxide (CH) into open dentin tubules. GMTA, WMTA, and CH particle dimensions were analyzed by flow particle image analysis (FPIA). Penetration of open dentin tubules into dentin discs was studied by scanning electron microscopy. Five samples of each material were randomly selected and prepared for this study. The GMTA averages for length (μm), width (μm), perimeter (μm), and aspect ratio were 1.94 ± 1.65, 1.43 ± 1.19, 5.61 ± 4.27, and 0.76 ± 0.14, respectively. Corresponding averages for WMTA were 2.04 ± 1.87, 1.49 ± 1.33, 5.88 ± 4.81, and 0.76 ± 0.14, and for CH were 2.26 ± 1.99, 1.62 ± 1.46, 6.70 ± 5.60, and 0.74 ± 0.15, respectively. The rank order of the averages for particle length, width and perimeter from the largest to the smallest material was CH > WMTA > GMTA. The rank order of the averaged aspect ratios was GMTA > WMTA > CH. SEM showed that all three materials, when deposited and agitated on dentin discs, penetrated the open dentin tubules. Tubule occlusion occurred as particle surface concentrations increased. Significant differences in particle length, width, perimeter, and aspect ratio were observed for GMTA, WMTA, and CH (P < 0.0001 in all cases). All particle types penetrated into open tubules when agitated on dentin discs; all tubules were eventually occluded as particle concentrations grew. PMID:25500926

  13. Influence of powder composition and morphology on penetration of Gray and White ProRoot mineral trioxide aggregate and calcium hydroxide into dentin tubules.

    PubMed

    Komabayashi, Takashi; Long, Leann; Ahn, Chul; Spears, Robert; Zhu, Qiang; C Eberhart, Robert

    2014-12-01

    This study examined the influence of powder composition and morphology on the penetration of Gray and White ProRoot mineral trioxide aggregate (GMTA, WMTA) and calcium hydroxide (CH) into open dentin tubules. GMTA, WMTA, and CH particle dimensions were analyzed by flow particle image analysis (FPIA). Penetration of open dentin tubules into dentin discs was studied by scanning electron microscopy. Five samples of each material were randomly selected and prepared for this study. The GMTA averages for length (μm), width (μm), perimeter (μm), and aspect ratio were 1.94 ± 1.65, 1.43 ± 1.19, 5.61 ± 4.27, and 0.76 ± 0.14, respectively. Corresponding averages for WMTA were 2.04 ± 1.87, 1.49 ± 1.33, 5.88 ± 4.81, and 0.76 ± 0.14, and for CH were 2.26 ± 1.99, 1.62 ± 1.46, 6.70 ± 5.60, and 0.74 ± 0.15, respectively. The rank order of the averages for particle length, width and perimeter from the largest to the smallest material was CH > WMTA > GMTA. The rank order of the averaged aspect ratios was GMTA > WMTA > CH. SEM showed that all three materials, when deposited and agitated on dentin discs, penetrated the open dentin tubules. Tubule occlusion occurred as particle surface concentrations increased. Significant differences in particle length, width, perimeter, and aspect ratio were observed for GMTA, WMTA, and CH (P < 0.0001 in all cases). All particle types penetrated into open tubules when agitated on dentin discs; all tubules were eventually occluded as particle concentrations grew. (J Oral Sci 56, 287-293, 2014).

  14. Quantitive evaluation of dentin sialoprotein (DSP) using microbeads - a potential early marker of root resorption

    PubMed Central

    LOMBARDO, L.; CARINCI, F.; MARTINI, M.; GEMMATI, D.; NARDONE, M.; SICILIANI, G.

    2016-01-01

    SUMMARY Purpose This study had the aim of comparing two different methods of analysing dentin sialoprotein (DSP) in the gingival crevicular fluid (GCF): the conventional eLISA approach and a new method involving the use of magnetic micro-beads coated with an antibody specific for DSP prior to eLISA analysis. Materials and methods GCF was taken from six patients following twelve weeks of orthodontic treatment using paper strips inserted into the mesial and distal sulci of the upper incisors, and analysed using both methods. Results Statistical analysis of the results using the Mann-Whitney non-parametric test showed that the micro-bead approach conferred more reliability and less variability on the conventional eLISA approach. Furthermore, this method, for the first time, enables the quantification of the DSP in the sample in ng/μl. Conclusions The innovative micro-bead/eLISA approach proposed provides a reliable means of quantifying the DSP in the GCF. PMID:28042441

  15. 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

  16. Synergistic effects of proanthocyanidin, tri-calcium phosphate and fluoride on artificial root caries and dentine collagen.

    PubMed

    Epasinghe, Don Jeevanie; Kwan, Stephen; Chu, Dora; Lei, May Mei; Burrow, Michael Frances; Yiu, Cynthia Kar Yung

    2017-04-01

    Proanthocyanidin has been shown to enhance dentine collagen stability and remineralization of artificial root caries. To evaluate the effect of proanthocyanidin (PA) in combination with tri-calcium phosphate (TCP) and fluoride (F) on resistance to collagen degradation and remineralization of artificial caries lesions. Demineralized root fragments (n=75) were randomly divided into five groups based on treatments: (i) 6.5% PA, (ii) TCP+F, (iii) TCP+F+6.5% PA, (iv) 1000ppm fluoride (Positive control) and (v) deionized water (control). Each specimen was subjected to pH cycling at 37(o) C for 8days. Lesion depth and mineral loss were evaluated using microradiography and confocal laser scanning microscopy. The type of crystal formation was determined by XRD spectra. To evaluate the stability of root caries lesions against collagenase challenge, highly purified type VII collagenase from Clostridium was added to obtain a remineralizing solution that contained 7.5U/mL collagenase and pH cycling was repeated. The different remineralizing solutions were collected after the pH cycling to assess the amount of hydroxyproline release. Collagen degradation depth and lesion depth were evaluated using transverse microradiography. Resistance to collagen degradation was determined using hydroxyproline assay. Data were analyzed using one-way ANOVA and Tukey multiple comparison tests. Results of one-way ANOVA showed that the test solutions had a significant effect on mineral loss (p<0.001) and lesion depth (p<0.001) of artificial root caries. The lowest lesion depth and mineral loss were observed in the TCP+F+PA (p<0.05) group. The XRD patterns showed hydroxyapatite formation on TCP+F-treated artificial caries lesions, which were not altered by the addition of PA. The addition of PA to TCP+F significantly reduced collagen degradation depth, when compared to TCP only group (p<0.001). Lesion depth was the lowest in the PA and TCP+F+PA groups following collagenase degradation (p<0

  17. Calcium loss from root canal dentin following EDTA, EGTA, EDTAC, and tetracycline-HCl treatment with or without subsequent NaOCl irrigation.

    PubMed

    Sayin, T Cem; Serper, Ahmet; Cehreli, Zafer C; Kalayci, Sukru

    2007-05-01

    The aim of this study was to determine the extent of calcium removal on root canal dentin after 17% EDTA, 17% EGTA, 15% EDTAC, and 1% tetracycline-HCl treatment; with or without subsequent use of 2.5% NaOCl. Extracted single-rooted human teeth were bisected longitudinally and the root halves (n=100) were isolated with nail varnish, leaving the root canal exposed. The samples were immersed in the test solutions for 1 and 5 minutes, after which the amount of calcium ion (Ca(2+)) release into the solutions was determined by flame photometry. Regardless of treatment time, all single (treatment solution only) and combined (treatment solution with subsequent NaOCl application) irrigation regimens removed significantly more Ca(2+) than control treatment (distilled water). Compared with other groups, treatment with 17% EDTA and 17% EDTA + 2.5% NaOCl resulted in the maximum amount of Ca(2+) removal from root canal dentin (p<0.05). All combined-treatment groups except 17% EGTA + 2.5% NaOCl removed significantly more Ca(2+) than their single-treatment versions (p<0.05). Within each test group, extending the treatment time to 5 minutes resulted in significantly more Ca(2+) removal (p<0.05).

  18. Evaluation of reparative dentin formation of ProRoot MTA, Biodentine and BioAggregate using micro-CT and immunohistochemistry

    PubMed Central

    Kim, Jia; Song, Young-Sang; Min, Kyung-San; Kim, Sun-Hun; Koh, Jeong-Tae

    2016-01-01

    Objectives The purpose of this study was to assess the ability of two new calcium silicate-based pulp-capping materials (Biodentine and BioAggregate) to induce healing in a rat pulp injury model and to compare them with mineral trioxide aggregate (MTA). Materials and Methods Eighteen rats were anesthetized, cavities were prepared and the pulp was capped with either of ProRoot MTA, Biodentine, or BioAggregate. The specimens were scanned using a high-resolution micro-computed tomography (micro-CT) system and were prepared and evaluated histologically and immunohistochemically using dentin sialoprotein (DSP). Results On micro-CT analysis, the ProRoot MTA and Biodentine groups showed significantly thicker hard tissue formation (p < 0.05). On H&E staining, ProRoot MTA showed complete dentin bridge formation with normal pulpal histology. In the Biodentine and BioAggregate groups, a thick, homogeneous hard tissue barrier was observed. The ProRoot MTA specimens showed strong immunopositive reaction for DSP. Conclusions Our results suggest that calcium silicate-based pulp-capping materials induce favorable effects on reparative processes during vital pulp therapy and that both Biodentine and BioAggregate could be considered as alternatives to ProRoot MTA. PMID:26877988

  19. Evaluation of reparative dentin formation of ProRoot MTA, Biodentine and BioAggregate using micro-CT and immunohistochemistry.

    PubMed

    Kim, Jia; Song, Young-Sang; Min, Kyung-San; Kim, Sun-Hun; Koh, Jeong-Tae; Lee, Bin-Na; Chang, Hoon-Sang; Hwang, In-Nam; Oh, Won-Mann; Hwang, Yun-Chan

    2016-02-01

    The purpose of this study was to assess the ability of two new calcium silicate-based pulp-capping materials (Biodentine and BioAggregate) to induce healing in a rat pulp injury model and to compare them with mineral trioxide aggregate (MTA). Eighteen rats were anesthetized, cavities were prepared and the pulp was capped with either of ProRoot MTA, Biodentine, or BioAggregate. The specimens were scanned using a high-resolution micro-computed tomography (micro-CT) system and were prepared and evaluated histologically and immunohistochemically using dentin sialoprotein (DSP). On micro-CT analysis, the ProRoot MTA and Biodentine groups showed significantly thicker hard tissue formation (p < 0.05). On H&E staining, ProRoot MTA showed complete dentin bridge formation with normal pulpal histology. In the Biodentine and BioAggregate groups, a thick, homogeneous hard tissue barrier was observed. The ProRoot MTA specimens showed strong immunopositive reaction for DSP. Our results suggest that calcium silicate-based pulp-capping materials induce favorable effects on reparative processes during vital pulp therapy and that both Biodentine and BioAggregate could be considered as alternatives to ProRoot MTA.

  20. Effect of Boric Acid Versus Conventional Irrigation Solutions on the Bond Strength Between Fiber Post 
and Root Dentin.

    PubMed

    Culhaoglu, Ahmet Kursad; Özcan, Erdal; Kilicarslan, Mehmet Ali; Seker, Emre

    2017-01-01

    To compare the effect of boric acid solutions of different percentages to conventional irrigation solutions on the adhesive bond strength between fiber posts and radicular dentin surface with different cement types. One hundred fifteen extracted human incisors were endodontically instrumented to a length of 14-15 mm, and 12-mm post spaces were prepared with specific drills. Cylindrical fiber posts (Panavia Post) were luted with two different composite cements (Panavia F 2.0, Panavia SA) and cut into 1-mm-thick slices. These specimens were randomly allocated to 5 groups according to the irrigant applied: 1. control, no irrigant; 2. 10 ml of 2% chlorhexidine; 3. 10 ml of 5.25% NaOCl for 5 min and 10 ml of 17% EDTA for 3 min; 4. 10 ml of 5% boric acid solution at a temperature of 55°C for 60 s; 5. 10% boric acid solution, conditions as in group 4. Bond strength was determined using the push-out test. Microscopic assessment and SEM evaluations were performed in combination with push-out tests. The push-out bond strengths of cervical segments were significantly higher than for the middle and apical segments in all groups. The type of irrigation solution used significantly affected the bond strengths of the posts. The 10% boric acid solution and EDTA + NaOCl irrigation solutions provided the highest bond strengths (p < 0.005). SEM analysis showed that the dentin tubules were open and the smear layer was completely removed when EDTA/NaOCl and 10% boric acid were used as irrigation agents. Boric acid solutions, especially at a concentration of 10%, can be a viable alternative to the conventional irrigants used during endodontic treatment. The extent to which the 10% boric acid solution successfully removed the smear layer and the ease of rinsing boric acid from the root surface are advantageous.

  1. Pull-out bond strength of a self-adhesive resin cement to NaOCl-treated root dentin: effect of antioxidizing agents

    PubMed Central

    Kachuei, Marzieh

    2014-01-01

    Objectives This study evaluated the effect of three antioxidizing agents on pull-out bond strengths of dentin treated with sodium hypochlorite. Materials and Methods Root canals of 75 single-rooted human teeth were prepared. Fifteen teeth were irrigated with normal saline for a negative control group, and the remaining 60 teeth (groups 2 - 5) with 2.5% NaOCl. The teeth in group 2 served as a positive control. Prior to post cementation, the root canals in groups 3 - 5 were irrigated with three antioxidizing agents including 10% rosmarinic acid (RA, Baridge essence), 10% hesperidin (HPN, Sigma), and 10% sodium ascorbate hydrogel (SA, AppliChem). Seventy-five spreaders (#55, taper .02, Produits Dentaires S.A) were coated with silica and silanized with the Rocatec system and ceramic bond. All the prepared spreaders were cemented with a self-adhesive resin cement (Bifix SE, Voco Gmbh) in the prepared canals. After storage in distilled water (24 h/37℃), the spreaders were pulled out in a universal testing machine at a crosshead speed of 1.0 mm/min. Pull-out strength values were analyzed by one-way ANOVA and Tukey's HSD test (α = 0.05). Results There were significant differences between study groups (p = 0.016). The highest pull-out strength was related to the SA group. The lowest strength was obtained in the positive control group. Conclusions Irrigation with NaOCl during canal preparation decreased bond strength of resin cement to root dentin. Amongst the antioxidants tested, SA had superior results in reversing the diminishing effect of NaOCl irrigation on the bond strength to root dentin. PMID:24790921

  2. Effects of soft-start irradiation on the depth of cure and marginal adaptation to dentin.

    PubMed

    Hasegawa, T; Itoh, K; Yukitani, W; Wakumoto, S; Hisamitsu, H

    2001-01-01

    Marginal adaptation of four resin composites, Clearfil APX, Estelite, Silux Plus and Z-100 cured with two irradiation methods (soft-start or high-power start) of a commercial soft-start halogen lamp unit (Elipar Highlight) were evaluated by measurement of the wall-to-wall contraction gap width. One-hundred and sixty cylindrical cavities, 3 mm in diameter and 1.5 mm in depth, were prepared in extracted human molars. The 80 cavity walls were treated with the Megabond system and each 20 cavities were filled with one of four resin composites. Then, each 10 fillings were irradiated by the soft-start method (soft-power light for 10 seconds followed by high-power light for 30 seconds) or high-power light for 40 seconds. The other 80 cavity walls were treated with an experimental bonding system consisting of 0.5M EDTA as a conditioner, 35% glyceryl mono-methacrylate as a primer and Clearfil Photo Bond as a bonding agent. The cavities were restored wtih the four resin composites and two irradiation methods, the same as the Megabond group. The contraction gap was measured with a light microscope and expressed in % of the cavity diameter. In addition, the curing capability of these two light sources was evaluated by measurement of the curing depth of the four resin composites using a split Teflon mold 4 mm in inner-diameter and 8 mm in height. Marginal gap formation of Clearfil APX, Estelite and Silux Plus with the experimental bonding system was completely prevented regardless of the kind of irradiation methods used. The deterioration of marginal adaptation caused by the Megabond system could not be improved by use of the soft-start method programmed in Elipar Highlight.

  3. Effect of waiting interval on chemical activation mode of dual-cure one-step self-etching adhesives on bonding to root canal dentin.

    PubMed

    Thitthaweerat, Suppason; Nakajima, Masatoshi; Foxton, Richard M; Tagami, Junji

    2012-12-01

    The purpose of this study was to evaluate the effect of waiting interval on the chemical activation of dual-cure one-step self-etching adhesives before placing resin core materials on the regional bond strength to root canal dentin. Forty-eight post spaces prepared in human lower premolars were applied with four dual-cure one-step self-etching adhesives Estelite Core Quick: ECB/ECQ, Clearfil DC Core Automix: CDB/CDC, Unifil Core EM: UNB/UNC, BeautiCore: BTB/BTC as the manufacturers' instructions. These adhesives were cured with light activation for 10 s, or chemical activation with 0, 10, and 30 s waiting intervals prior to placing resin core material. Resin core materials were then placed into the post space and light-cured for 60 s. After 24h water storage, each specimen was serially sliced into 8, 0.6 mm × 0.6 mm thick beams for the μTBS test. The regional μTBS data were analyzed using three-way ANOVA and Dunnett's T3 test (p < 0.05). For the chemical activation with 10 and 30 s waiting intervals, ECB and CDB exhibited significantly improved μTBS, whereas for UNB and BTB, the μTBS were not significantly different but increased with waiting interval. On the other hand, light-activation of all the adhesives produced significantly higher μTBS to root canal dentin than chemical activation (p < 0.05), except for the UNB group. For the chemical activation of dual-cure one-step self-etching adhesives, a waiting interval prior to placing resin core material improved μTBS to root canal dentin. Polymerising the adhesives before polymerisation reaction of resin core material would be effective for bonding to root canal dentin. For chemical activation mode as well as light activation mode, pre-curing of adhesive layer before proceeding polymerisation of resin filling material would produce higher bonding performance to dentin in the cavity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Push-Out Bond Strength of Dorifill, Epiphany and MTA-Fillapex Sealers to Root Canal Dentin with and without Smear Layer

    PubMed Central

    Forough Reyhani, Mohammad; Ghasemi, Negin; Rahimi, Saeed; Salem Milani, Amin; Mokhtari, Hadi; Shakouie, Sahar; Safarvand, Hossein

    2014-01-01

    Introduction: The aim of the present experimental study was to evaluate the push-out bond strength of Dorifill, Epiphany and MTA-Fillapex sealers to root canal dentin in presence and absence of smear layer (SL). Methods and Materials: Sixty human single-rooted teeth were selected and divided into six groups (n=10). The canal irrigation protocol in groups 1, 3 and 5 consisted of 2.5% NaOCl during instrumentation and normal saline at the end of preparation plus a 5-min irrigation with 17% ethylenediaminetetraacetic acid (EDTA). In the remaining groups, normal saline was used for canal irrigation. The root canals were filled with Epiphany/Resilon (groups 1 and 2), Dorifill/gutta-percha (groups 3 and 4) and MTA-Fillapex/gutta-percha (groups 5 and 6). After two weeks of storage in 95% relative humidity at 37ºC, 2 mm-thick dentin disks were prepared from coronal third of each root. The push-out bond strength test was carried out using a universal testing machine. Data were analyzed with the two-way ANOVA and post hoc Tukey’s tests. Statistical significance was defined at 0.05. Results: The highest (3.06±0.38 MPa) and lowest (1.16±0.32 MPa) push-out bond strength values were recorded in Epiphany/Resilon-NaOCl/EDTA and Dorifill/gutta-percha/normal saline groups, respectively. There were significant differences in the bond strength of sealers (P<0.05). In addition, elimination of the SL significantly increased the bond strength of all sealers (P<0.05). Conclusion: The Epiphany/Resilon group exhibited the highest push-out bond strength in the presence and absence of the SL. Elimination of the SL resulted in a significant increase in the bond strength of all the sealers to dentin. PMID:25386203

  5. Root anomalies and dentin dysplasia in autosomal recessive hyperphosphatemic familial tumoral calcinosis (HFTC)

    PubMed Central

    Vieira, Alexandre R.; Lee, Moses; Vairo, Filippo; Leite, Julio Cesar Loguercio; Munerato, Maria Cristina; Visioli, Fernanda; D’Ávila, Stéphanie Rodrigues; Wang, Shih-Kai; Choi, Murim; Simmer, James P.; Hu, Jan C-C.

    2015-01-01

    Hyperphosphatemic familial tumoral calcinosis (HFTC, OMIM #211900) is an autosomal recessive metabolic disorder characterized by hyperphosphatemia, tooth root defects, and the progressive deposition of calcium phosphate crystals in periarticular spaces, soft tissues, and sometimes bone.1 In this HFTC case report, we document the dental phenotype associated with a homozygous missense mutation (g.29077 C>T; c.484 C>T; p.Arg162*) in GALNT3 (OMIM 6017563), a gene encoding UDP-GalNAc transferase 3 that catalyzes the first step of O-linked oligosaccharide biosynthesis in the Golgi. The medical and dental pathology is believed to be caused primarily by high serum phosphate levels (hyperphosphatemia), which, in turn, is caused by failure of GALNT3 to glycosylate the phosphate regulator protein FGF23, impairing its ability inhibit reabsorption of filtered phosphate in the kidneys. PMID:26337219

  6. The permeability of dentine from bovine incisors in vitro.

    PubMed

    Tagami, J; Tao, L; Pashley, D H; Horner, J A

    1989-01-01

    The permeability of coronal dentine was investigated by measuring the hydraulic conductance of dentine discs. Reductions in dentine thickness from the enamel side of disc resulted in a greater increase in permeability than reductions from the pulpal side. Scanning electron microscopy revealed fewer dentinal tubules with smaller diameters in superficial dentine than in deep dentine. The permeability of coronal incisor bovine dentine is six to eight times less than that of unerupted coronal human third molar dentine but similar to that of human root dentine.

  7. Effect of Resin Cement Porosity on Retention of Glass-Fiber Posts to Root Dentin: An Experimental and Finite Element Analysis.

    PubMed

    Da Silva, Natércia Rezende; Aguiar, Grazielle Crystine Rodrigues; Rodrigues, Monise de Paula; Bicalho, Aline Aredes; Soares, Priscilla Barbosa Ferreira; Veríssimo, Crisnicaw; Soares, Carlos José

    2015-01-01

    The aim of this study was to evaluate the effect of porosity of self-adhesive resin on the stress distribution, post retention and failure mode of fiber post cemented to human root dentin. Ten human central upper incisors with circular root canal were selected. They were sectioned with 15 mm and were endodontically filled. The roots were scanned using micro-CT after post space preparation for root filling remaining evaluation. Fiber posts were cemented using self-adhesive resin cement (Rely X U200, 3M-ESPE). Two 1-mm-thick slices from the cervical, medium and apical thirds were scanned for resin cement bubbles volume measurements and submitted to a push-out test (PBS). Three operators using stereomicroscopy and confocal laser microscopy classified the failure mode. Stress distributions during the push-out test were analyzed using 3D finite element analysis. PBS values (MPa) were submitted to one-way ANOVA and Tukey's post hoc tests and the failure modes using the Kappa coefficient to assess inter-operator agreement. Chi-square test was used to determine significant differences between the methods ( = 0.05). Push-out bond strength was significantly affected by the bubbles presence in all root depth (p<0.05). The stress concentration was higher when the bubbles were present. Adhesive dentin/resin cement interface failure was the most frequent type of failure. Confocal microscopy was better than stereomicroscopy for failure analysis. Bubbles generated during resin cement insertion into the root canal negatively affect the stress distribution and the bond strength. The use of confocal microscopy is recommended for failure analysis.

  8. Decalcifying effect of 15% EDTA, 15% citric acid, 5% phosphoric acid and 2.5% sodium hypochlorite on root canal dentine.

    PubMed

    Pérez-Heredia, M; Ferrer-Luque, C M; González-Rodríguez, M P; Martín-Peinado, F J; González-López, S

    2008-05-01

    To evaluate and compare ex vivo the decalcifying effect of 15% EDTA, 15% citric acid, 5% phosphoric acid and 2.5% sodium hypochlorite on root canal dentine. Two 2-mm-thick slices were cut from the coronal third of the root of 10 human incisors. Each slice was sectioned into two equal parts. Specimens were assigned to one of four groups (n = 10) for immersion in 20 mL of either 15% EDTA, or 15% citric acid, 5% phosphoric acid or 2.5% NaOCl, for three time periods (5, 10 and 15 min). The concentration of Ca(2+) extracted from the dentine was measured by atomic absorption spectrophometry. The amount of calcium extracted was analysed using the Kruskal-Wallis test for global comparisons and the Mann-Whitney U-test for pairwise comparisons. In the three time periods, 15% EDTA and 15% citric acid extracted the largest amount of calcium, with no significant differences between them. The 2.5% NaOCl solution extracted insignificant amounts of calcium, whereas 15% EDTA extracted 86.72% of the calcium in the first 5 min, and 15% citric acid and 5% phosphoric acid had a similar pattern of calcium removal (77.03% and 67.08% in first 5 min, respectively). Solutions of 15% EDTA, 15% citric acid and 5% phosphoric acid decalcify root dentine, with most calcium extracted during the first 5 min of action. The efficacy of 15% citric acid and 15% EDTA solutions was significantly greater than that of 5% phosphoric acid solution at each time period (5, 10 and 15 min).

  9. Bond strength of self-adhesive resin cement to root dentin. Comparison of photon-initiated photoacoustic streaming technique with needle and ultrasonic irrigation.

    PubMed

    Arslan, Hakan; Akcay, Merve; Saygili, Gokhan; Keskı, Ahmet; MeŞe, İbrahim Talha; Gok, Adem; Dalli, Mehmet

    2015-07-01

    The aim of this study was to investigate the effects of photon-initiated photoacoustic streaming (PIPS) with various irrigating solutions on the bond strength of a self-adhesive resin cement to root dentin. Seventy-two mandibular premolar roots were divided into six groups after post space preparation and treated with a needle irrigation with distilled water and NaOCl, ultrasonic irrigation with NaOCl, PIPS with NaOCl, PIPS with EDTA and PIPS with distilled water at 0.3 W, 15 Hz and 20 mJ per pulse for 60 s. Fiber posts were cemented with a newly marketed, self-adhesive resin cement. The data obtained from the push-out tests were analyzed using analysis of variance (ANOVA) and LSD post-hoc tests (p = 0.05). PIPS with distilled water resulted in higher push-out values than those of needle (with both distilled water and NaOCl) and ultrasonic irrigation (p < 0.05). The use of PIPS may provide higher bond strength of self-adhesive resin cement to root dentin than needle and ultrasonic irrigation techniques.

  10. Interfacial nanoleakage and bonding of self-adhesive systems cured with a modified-layering technique to dentin of weakened roots.

    PubMed

    Mobarak, E; Seyam, R

    2013-01-01

    The purpose of the study was to evaluate the nanoleakage and bond strength of different self adhesive systems cured with a modified-layering technique (MLT) to dentin of weakened roots. Twenty-one maxillary incisors were decoronated and then root canals were instrumented and obturated with the cold lateral compaction technique. Weakened roots were simulated by flaring root canals until only 1 mm dentin thickness remained. Teeth were distributed into three groups. The canals were backfilled with Vertise Flow (VF group), a self-adhering system, following a modified-layering technique using two light-transmitting posts, sizes 6 and 3. DT Light Post size 2 was cemented using the same material. Remaining roots were prepared and cured in the same way as the VF group. However, in the TS/MF group, Clearfil Tri-S Bond (TS) adhesive and Clearfil Majesty Flow (MF) composite were used, while in the ED/PF group, ED primer II (ED)/Panavia F2.0 (PF) were used. After one week of storage, each root was sectioned to obtain six slices (two slices from each root third: coronal, middle and apical) of 0.9 ± 0.1 mm thickness. Interfacial nanoleakage expression was analyzed using a field emission scanning electron microscope (FEG-SEM), and the micro push-out bond strength (μPOBS) was measured at different root regions. Modes of failure were also determined using SEM. Data were statistically analyzed using two-way analysis of variance with repeated measures and Tukey post hoc test (p≤0.05). With MLT, all adhesive systems showed nanoleakage. For μPOBS, there was a statistically significant effect for adhesive systems (p<0.001) but not for root region (p<0.64) or for their interaction (p=0.99). Tukey post hoc test revealed that the bond strength of the VF group was significantly higher than the TS/MF and ED/PF groups for all root regions. All of the tested self-adhesive systems cured using MLT had slight nanoleakage and were not sensitive to root regional differences. Self

  11. Influence of blood contamination before or after surface treatment on adhesion of 4-META/MMA-TBB resin to root dentin.

    PubMed

    Takefu, Hiroe; Shimoji, Shinji; Sugaya, Tsutomu; Kawanami, Masamitsu

    2012-02-03

    The purpose of this study was to evaluate the influence of blood contamination before or after surface treatment on adhesion of 4-META/MMA-TBB resin. After bovine root dentin surfaces were contaminated with blood before or after dentin surface treatment with 10-3 solution, the contaminated surface was rinsed with water, air-dried, or re-treated with 10-3 solution. Dye leakage and microtensile bond strength (MTBS) of 4-META/MMA-TBB resin to dentin were measured after storage in water for 24 h. When blood contamination occurred before surface treatment, there was no significant difference in the leakage value and MTBS as compared with that of the uncontaminated group. When blood contamination occurred after surface treatment, the leakage value increased and MTBS significantly decreased (p<0.05) even if the blood was washed away. However, when the surface was re-treated with 10-3 solution after rinsing with water, the leakage value and MTBS were restored to those of the uncontaminated group.

  12. Computed Tomography Evaluation of Canal Transportation and Volumetric Changes in Root Canal Dentin of Curved Canals Using Mtwo, ProTaper and ProTaper Next Rotary System-An In-vitro Study

    PubMed Central

    Shivashankar, Mayuri Biccodu; Jayasheel, Arun; Kenchanagoudra, Mallikarjun Goud

    2016-01-01

    Introduction Complete cleaning and shaping of root canal system is of paramount importance to achieve a successful root canal treatment. There are various rotary Ni-Ti systems available in the market to achieve mechanical goal of root canal preparation. But aggressive preparation of root canal with such systems would result in canal transportation and excess root dentin removal that would be one of the major reasons to decide the prognosis of root canal treated tooth. Aim The present study was conducted to compare the root canal preparation in terms of canal transportation and volumetric changes in the root canal dentin among three Ni-Ti file systems, namely Mtwo, ProTaper (PT) and ProTaper NEXT (PTN) file system, using Computed Tomography (CT). Materials and Methods A total of 45 mesiobuccal root canals of extracted first molar teeth with completely formed root apices and angle of curvature ranging between 10°- 35° were selected. These teeth were randomly divided into three experimental groups containing 15 teeth each, based on rotary system used. Group-I: Mtwo files, Group-II: PT files and Group-III: PTN files. Pre-instrumentation CT images were obtained at three cross-sectional planes – 3mm, 7mm and 11mm from apical end of the root. Similarly, post-instrumentation images were obtained. Shortest distance from the edge of the canal to the periphery of the root was analyzed by using Analysis of Variance. Results All three file systems tested in the present study presented similar behaviour with respect to the root canal transportation. Lesser canal transportation was recorded in Mtwo. But no statistically significant difference was seen in terms of canal transportation and volume of dentin removed between all three rotary systems (p>0.05). Conclusion Mtwo, PT and PTN rotary systems have similar behaviour with respect to canal transportation and volume of dentin removed. PMID:28050495

  13. A comparative study of temperature elevation on human teeth root surfaces during Nd:YAG laser irradiation in root canals.

    PubMed

    Strakas, D; Franzen, R; Kallis, A; Vanweersch, L; Gutknecht, N

    2013-11-01

    The purpose of this study was to evaluate the temperatures on the root surfaces during Nd:YAG laser irradiation in root canals using pulse durations of 180 and 320 μs. Thirty extracted human teeth were used in this study. The teeth were enlarged up to ISO 40 (multi-rooted) or up to ISO 60 (single-rooted) by conventional technique using K-files. Then the teeth were placed into a water bath with a constant temperature of 37 °C and then irradiated with an Nd:YAG laser having an output power of 1.5 W, a frequency of 15 Hz, using an optic fiber of 200 μm diameter. The temperature on the root surface was measured by means of attaching thermocouples in three areas (coronal, mesial, and apical regions) of the root canals. The thermographic study showed that the average temperature elevation for both pulse durations on the root surfaces was less than 9 °C. There was no significant difference in the observed temperatures in coronal and mesial areas. Though a higher increase of temperature was observed in the apical region when the pulse length of the Nd:YAG laser was 320 μs. The results of the study showed that the temperature rises during Nd:YAG laser irradiation with parameters used in this study minimal to cause damage on bone and periodontal tissues. Moreover, it was suggested that in order to have lower temperature in the apical region, an Nd:YAG laser with a pulse length of 180 μs is preferred than one with a pulse length of 320 μs.

  14. Effect of dentin hardness on ablation rate with Er:YAG laser.

    PubMed

    Osuka, Keigo; Amagai, Tetsuya; Kukidome, Nobuyuki; Takase, Yasuaki; Aida, Shigeo; Hirai, Yoshito

    2009-06-01

    This study used artificially demineralized bovine dentin to ascertain the effect of hardness of demineralized dentin on ablation rate with the Er:YAG laser. Before restoration of carious teeth, it is necessary to ablate any infected dentin that cannot be remineralized due to softening by the invading caries. A correlation has been suggested between the ablation efficiency of the Er:YAG laser and the progression of caries in dentin. To the best of our knowledge, no studies have investigated the relationship between degree of demineralization by dentinal caries and ablation rate with the Er:YAG laser. Bovine mandibular anterior tooth roots were used as dentin samples. Each sample was soaked in a demineralizing solution (2 M lactic acid, pH 4.0) for 3 d to obtain demineralized dentin (DD) samples. Another group of samples were prepared without demineralization as a sound dentin (SD) group for comparison. After determining the Knoop hardness number (KHN) of each sample, the dentin surface was ablated with an Er:YAG laser. Tip output and pulse rate were set at 50 mJ and 20 pulses per second (pps), respectively, and the water spray was set at 3.5 mL/min. Ablation width, depth, and volume were measured following irradiation. In the DD group, dentin hardness was 10.4 +/- 1.6 KHN at 100 microm from the surface. In the sound dentin group, Knoop hardness was 51.0 +/- 1.6 KHN cross-sectionally throughout. No differences were observed from the surface to a depth of 2000 microm. In the DD group, dentin ablation volume at the superficial demineralized layer was 2888 +/- 272 x 10(4) microm. In the SD group, dentin ablation volume was 1298 +/- 219 microm(3). The relationship between ablation volume and Knoop hardness was defined as Y = -40.699x + 3350, revealing a marked negative correlation. The results demonstrate that the ablation volume for demineralized dentin was greater than that for sound dentin. The results suggest that the Er:YAG laser is capable of ablating infected

  15. Effect of toothpastes containing different NaF concentrations or a SnF2/NaF combination on root dentine erosive lesions, in vitro

    PubMed Central

    Koletsi-Kounari, Haroula; Mamai-Homata, Eleni

    2016-01-01

    Background Fluoride toothpastes presumably offer some protection against acid erosion. However, uncertainty exists towards fluoride’s efficacy relatively to the concentration and the type of chemical compound used. This in vitro study evaluated the relative efficacy of toothpastes containing sodium fluoride in different concentrations or a stabilized stannous fluoride/sodium fluoride system on root dentine erosion. Material and Methods Bovine dentin specimens were allocated into four groups (n=10): control (no F), 1450ppm F (as NaF), 5000ppm F (as NaF) and 1450ppm F (1100ppm as stabilized SnF2 and 350ppm as NaF)/sodium hexamethaphosphate. The specimens were submitted to 6 daily cycles of erosion (0.3% v/v citric acid, pH=3.2, 20 min) and remineralization (~22h), interspersed by 2-min immersions in 1:3 w/v of dentifrice/distilled water slurries. Subsequently, they were subjected to a 24-h acid resistance test (0.3% v/v citric acid, pH=3.2) without any further treatments. Surface loss was quantified by contact profilometry. Data were analysed through one-way ANOVA and Bonferroni’s tests (p≤0.05). Results In both experiments, all fluoride groups, showed significantly less tissue loss compared to the control (p<0.001-p=0.018). During erosion cycling, no significant differences were found among the fluoride groups. During the acid resistance test, the 5000ppm F toothpaste produced significantly superior effect than both 1450ppm F products (p=0.010, (p<0.001), which performed similarly. Conclusions Under less aggressive erosive conditions, fluoride toothpastes did not differ in their ability to protect dentine surfaces. However, in severely erosive environment, the 5000ppm F toothpaste performed superiorly to the other tested products. Key words:Dentine, sodium fluoride, stannous fluoride, tooth erosion, toothpaste, contact profilometry. PMID:27957274

  16. Temperature variation at the external root surface during 980-nm diode laser irradiation in the root canal.

    PubMed

    Alfredo, E; Marchesan, M A; Sousa-Neto, M D; Brugnera-Júnior, A; Silva-Sousa, Y T C

    2008-07-01

    To assess the temperature variation in the cervical, middle and apical thirds of root external wall, caused by 980-nm diode laser irradiation with different parameters. The roots of 90 canines, had their canals instrumented and were randomly distributed into 3 groups (n=30) according to the laser potency (1.5 W, 3.0 W and 5.0 W). Each group was subdivided into 3 (n=10) according to the frequency (CM, 100 Hz and 1000 Hz), and each subgroup divided into 2 (n=5): dried canal or filled with distilled water. The maximum temperature values were collected by 3 thermocouples located at each third of the root external wall and recorded by digital thermometers. The groups irradiated in the continuous mode (CM) presented the highest values (11.82+/-5.78), regardless of the canals were dry or not, which were statistically different (p<0.01) from those obtained with 100 Hz (6.22+/-3.64) and 1000 Hz (6.00+/-3.36), which presented no statistical difference between them (p>0.01). The groups irradiated with 5.0 W presented the greatest temperature variation (12.15+/-5.14), followed by 3.0 W (7.88+/-3.92) and 1.5 W (4.02+/-2.16), differing between them (p<0.01). The cervical third of the root presented the highest temperature rises (9.68+/-5.80), followed by the middle (7.66+/-4.87) and apical (6.70+/-4.23), with statistical difference among them (p<0.01). After 30s from the end of irradiation, all the specimens presented temperature variation lower than 10 degrees C. Application of 980-nm diode laser in the root, at 1.5 W in all operating modes, and 3.0 W, in the pulsed mode, for 20s, can safely be used in endodontic treatment, irrespective of the presence of humidity.

  17. Infected Dentine Revisited.

    PubMed

    Kidd, Edwina; Fejerskov, Ole; Nyvad, Bente

    2015-11-01

    Dentine becomes infected as a result of caries lesion formation on root surfaces and when lesions progress following cavitation of enamel lesions. However, this infection is unimportant because the driving force for lesion formation and progression is the overlying biofilm. This explains why root surface caries can be controlled by mechanical plaque control and fluoride, and restorations are not needed to arrest these lesions. Similarly, the infected dentine in cavitated coronal lesions does not have to be removed to arrest the lesion. If the lesion is either accessible or opened for cleaning by the patient or parent, the lesion can be arrested. Sealing of infected dentine within the tooth, either by a Hall crown in the primary dentition or by partial caries removal prior to placing a well-sealed filling, will also arrest the lesion. When restoring deep lesions in symptomless, vital teeth, vigorous excavation of infected dentine is likely to expose the pulp and make root canal treatment necessary. Thus complete excavation'is not needed and should be avoided. CPD/CLINICAL RELEVANCE: Root surface caries can be arrested by cleaning and fluoride application. Restorations are not essential. Vigorous excavation of softened dentine in deep cavities of symptomless, vital teeth is contra-indicated. It is not needed and increases the risk of pulp exposure.

  18. Dentin ablation-rate measurements in endodontics witj HF and CO2 laser radiation

    NASA Astrophysics Data System (ADS)

    Makropoulou, Mersini I.; Serafetinides, Alexander A.; Khabbaz, Marouan; Sykaras, Sotirios; Tsikrikas, G. N.

    1996-01-01

    Recent studies focused on the ability of the laser light to enlarge the root canal during the endodontic therapy. The aim of this research is the experimental and theoretical study of the ablation rate of two infrared laser wavelengths on dentin. Thirty freshly extracted human teeth were longitudinally sectioned at thicknesses ranged from 0.5 to 2 mm, and irradiated on the root canal dentin. The measured ablation rates in dentinal wall of the root canal showed that the HF laser at 2.9 micrometer can more effectively penetrate into the tissue, whereas the carbon dioxide laser at 10.6 micrometer leads to high thermal damage of the ablation crater surroundings.

  19. Combination of aligned PLGA/Gelatin electrospun sheets, native dental pulp extracellular matrix and treated dentin matrix as substrates for tooth root regeneration.

    PubMed

    Chen, Gang; Chen, Jinlong; Yang, Bo; Li, Lei; Luo, Xiangyou; Zhang, Xuexin; Feng, Lian; Jiang, Zongting; Yu, Mei; Guo, Weihua; Tian, Weidong

    2015-06-01

    In tissue engineering, scaffold materials provide effective structural support to promote the repair of damaged tissues or organs through simulating the extracellular matrix (ECM) microenvironments for stem cells. This study hypothesized that simulating the ECM microenvironments of periodontium and dental pulp/dentin complexes would contribute to the regeneration of tooth root. Here, aligned PLGA/Gelatin electrospun sheet (APES), treated dentin matrix (TDM) and native dental pulp extracellular matrix (DPEM) were fabricated and combined into APES/TDM and DPEM/TDM for periodontium and dental pulp regeneration, respectively. This study firstly examined the physicochemical properties and biocompatibilities of both APES and DPEM in vitro, and further investigated the degradation of APES and revascularization of DPEM in vivo. Then, the potency of APES/TDM and DPEM/TDM in odontogenic induction was evaluated via co-culture with dental stem cells. Finally, we verified the periodontium and dental pulp/dentin complex regeneration in the jaw of miniature swine. Results showed that APES possessed aligned fiber orientation which guided cell proliferation while DPEM preserved the intrinsic fiber structure and ECM proteins. Importantly, both APES/TDM and DPEM/TDM facilitated the odontogenic differentiation of dental stem cells in vitro. Seeded with stem cells, the sandwich composites (APES/TDM/DPEM) generated tooth root-like tissues after being transplanted in porcine jaws for 12 w. In dental pulp/dentin complex-like tissues, columnar odontoblasts-like layer arranged along the interface between newly-formed predentin matrix and dental pulp-like tissues in which blood vessels could be found; in periodontium complex-like tissues, cellular cementum and periodontal ligament (PDL)-like tissues were generated on the TDM surface. Thus, above results suggest that APES and DPEM exhibiting appropriate physicochemical properties and well biocompatibilities, in accompany with TDM, could

  20. In vitro study of the effect of a pulsed 10.6μm CO2 laser and fluoride on the reduction of carious lesions progression in bovine root dentin

    NASA Astrophysics Data System (ADS)

    Parisotto, Thaís M.; Sacramento, Patrícia A.; Alves, Marcelo C.; Puppin-Rontani, Regina M.; Gavião, Maria Beatriz D.; Nobre-dos-Santos, Marin"s.

    2010-02-01

    The aim of the present study was to evaluate the combined in vitro effects a pulsed 10.6 μm CO2 laser and fluoride on the reduction of carious lesion progression in root dentin. Sixty five slabs of previously demineralized bovine root dentin were assigned into five groups (n=13): control (no treatment), acidulated phosphate fluoride gel 1.23% (FFA), CO2 Laser (L), FFA+L, L+FFA. The lasered groups were irradiated with 4.0J/cm2. After a 7 day pH cycling regime, the knoop hardness number (KHN) was determined by cross-sectional microhardness testing (5g, 5s, 10-60 μm, 10 μm interval). The data was analyzed by ANOVA and Student's t-test (α= 0.05). A significant interaction between KHN and the indentation depths was found (p<0.05). At 10-20 μm, FFA+L (KHN:12.12+/-0.95/13.07+/-1.03) and FFA (KHN:12.86+/-4.54/12.60+/-3.93) inhibited caries progression when compared to control group (KHN:8.76+/-0.95/9.50+/-1.03) (p<0.05), but did not differ with neither each other nor from group L (p>0.05). At 30 μm, the KHN was significantly higher than the control only in the FFA group (KHN:15.35+/-1.16). At 40 μm, the groups FFA (KHN: 15.87+/-3.76), L (KHN: 15.57+/-5.71) and L+FFA (KHN:15.50+/-5.08) were capable of significantly inhibiting caries progression, however they did not differ each other (p>0.05). At depths of 50-60 μm, only group L (KHN:17.05+/-1.29/18.26+/-1.30) differed statistically from the control (KHN:13.43+/-1.24/13.81+/-1.25), but not from the other groups. In conclusion, CO2 laser alone was able to inhibit caries progression in the deepest layers. However, no synergistic effect was obtained when CO2 laser irradiation and FFA application and were combined.

  1. Optical properties of human radicular dentin: ATR-FTIR characterization and dentine tubule direction influence on radicular post adhesion

    NASA Astrophysics Data System (ADS)

    Quinto, Jose; Zamataro, Claudia B.; Benetti, Carolina; Dias, Derly A.; Blay, Alberto; Zezell, Denise Maria

    2015-06-01

    Knowledge of dental structures is essential for understanding of laser interaction and its consequences during adhesion processes. Tubule density in dentin ranges from 4.900 to 90.000 per mm2, for diameters from 1 to 3 μm. Light propagation inside the tubules is associated with tubules orientation. To the best of our knowledge, there is no previous work in literature characterizing physical-chemical alterations in dentin. The dentin samples were irradiated with a Er,Cr:YSGG Laser at wavelength 2.78 μm, with an energy density of 9.46 J/cm2 , above the ablation threshold. ATRFTIR at wavenumbers 2000 to 700 cm-1 was used to evaluate the differences among third root region and tubules orientation.

  2. Influence of chemical irrigants on the tensile bond strength of an adhesive system used to cement glass fiber posts to root dentin.

    PubMed

    Pelegrine, Rina Andréa; De Martin, Alexandre Sigrist; Cunha, Rodrigo Sanches; Pelegrine, André Antonio; da Silveira Bueno, Carlos Eduardo

    2010-11-01

    The aim of this study was to evaluate the influence of endodontic irrigants on the tensile bond strength of an adhesive system used to cement glass fiber posts to dentin. Fifty bovine roots were divided into 5 groups according to the solution used during instrumentation: G1, 0.9% NaCl (control); G2, 1.0% NaOCl; G3, 2.5% NaOCl; G4, 5.25% NaOCl; G5, 2% chlorhexidine gel + 0.9% NaCl. The root canals were obturated with gutta-percha and AH Plus sealer, and the glass fiber posts were cemented with Clearfil SE Bond/RelyX ARC. The specimens were submitted to tensile strength testing and the results were analyzed by analysis of variance. There were no statistically significant differences regarding the irrigant solution factor (P > .70). It was concluded that the different irrigant solutions did not affect the tensile bond strength of the fixation system used to cement the intraradicular glass fiber posts to dentin. Copyright © 2010 Mosby, Inc. All rights reserved.

  3. Influence of Laser Activated Irrigation with two Erbium Lasers on Bond Strength of Inidividually Formed Fiber Reinforced Composite Posts to Root Canal Dentin.

    PubMed

    Parčina, Ivana; Amižić; Miletić, Ivana; Ionescu, Andrei C; Brambilla, Eugenio; Gabrić, Dragana; Baraba, Anja

    2016-12-01

    The aim of this in vitro study was to investigate the effect of laser activated irrigation (LAI) using two erbium lasers on bond strength of individually formed fiber-reinforced composite (FRC) posts to root canal dentin. Twenty-seven single-rooted human teeth were endodontically treated and after post space preparation divided into three groups (n=9 per group), according to the pre-treatment of post space preparation: 1) Conventional syringe irrigation (CSI) and saline; 2) Er.YAG photon-induced photoacoustic streaming (PIPS) technique and saline; 3) Er,Cr:YSGG activated irrigation with RFT2 tip. Two specimens from each group were used for SEM analysis. The remaining specimens (n=7 per group) received individually formed FRC post, everStick POST, luted with self-adhesive cement, G-CEM LinkAce. After cementation, the roots were perpendicularly sectioned into 1 mm thin sections and a push-out test was carried out (0.5 mm/min). The data were calculated as megapascals and were log transformed and statistically analysed using one-way ANOVA at the level of significance set at 5%. In the control group, the smear layer was still present. In the Er:YAG group, the smear layer was removed. In the Er,Cr:YSGG group, the smear layer was partially removed. The Er,Cr:YSGG group achieved the highest bond strength values, followed by the control group and then the Er:YAG group, but no statistically significant difference was found in bond strength values in the tested group of post space pretreatment (p=0.564). LAI using two erbium lasers, with PIPS or RFT2 tip, did not affect the bond strength of individually formed FRC posts to root canal dentin.

  4. Influence of chlorhexidine and ethanol on the bond strength and durability of the adhesion of the fiber posts to root dentin using a total etching adhesive system.

    PubMed

    Cecchin, Doglas; de Almeida, José Flávio Affonso; Gomes, Brenda P F A; Zaia, Alexandre Augusto; Ferraz, Caio Cesar Randi

    2011-09-01

    The aim of this study was to investigate the effects of pretreatment of gel chlorhexidine (CHX) and ethanol (EtOH) on the bond strength and durability of the adhesion of the fiber post relined with resin composite to the root dentin using a total etch adhesive system. Forty bovine incisor roots were divided into four groups after phosphoric acid etching: irrigation with physiologic solution (control), 5 minutes with CHX, 1 minute with EtOH, and 5 minutes with chlorhexidine followed by 1 minute with EtOH. Fiber posts relined with resin composite were cemented with either RelyX ARC (3M ESPE, St Paul, MN) and a total etch adhesive system Scotchbond Multi-Purpose (3M ESPE). Each group was randomly divided into two subgroups: 24 hours of storage and 12 months of storage. All roots were sectioned transversely, and the push-out test was performed. Failure modes were observed, and the bond strength means were analyzed by analysis of variance and the Tukey test (α = 0.05). CHX irrigation resulted in homogeneous bond strength values at 24 hours and 12 months of storage (P < .05). A significant bond strength decrease was noticed after 12 months of storage when irrigations were performed with physiologic solution and EtOH application only or associated with CHX (P < .05). The use of CHX pretreatment could preserve the bond strength of the fiber post relined with resin composite to root dentin for 12 months. The use of EtOH and CHX followed by EtOH did not preserve the bond strength of the total etch adhesive system Scotchbond Multi-Purpose. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. Influence of Laser Activated Irrigation with two Erbium Lasers on Bond Strength of Inidividually Formed Fiber Reinforced Composite Posts to Root Canal Dentin

    PubMed Central

    Parčina, Ivana; Miletić, Ivana; Ionescu, Andrei C.; Brambilla, Eugenio; Gabrić, Dragana; Baraba, Anja

    2016-01-01

    Objective The aim of this in vitro study was to investigate the effect of laser activated irrigation (LAI) using two erbium lasers on bond strength of individually formed fiber-reinforced composite (FRC) posts to root canal dentin. Materials and methods Twenty-seven single-rooted human teeth were endodontically treated and after post space preparation divided into three groups (n=9 per group), according to the pre-treatment of post space preparation: 1) Conventional syringe irrigation (CSI) and saline; 2) Er.YAG photon-induced photoacoustic streaming (PIPS) technique and saline; 3) Er,Cr:YSGG activated irrigation with RFT2 tip. Two specimens from each group were used for SEM analysis. The remaining specimens (n=7 per group) received individually formed FRC post, everStick POST, luted with self-adhesive cement, G-CEM LinkAce. After cementation, the roots were perpendicularly sectioned into 1 mm thin sections and a push-out test was carried out (0.5 mm/min). The data were calculated as megapascals and were log transformed and statistically analysed using one-way ANOVA at the level of significance set at 5%. Results In the control group, the smear layer was still present. In the Er:YAG group, the smear layer was removed. In the Er,Cr:YSGG group, the smear layer was partially removed. The Er,Cr:YSGG group achieved the highest bond strength values, followed by the control group and then the Er:YAG group, but no statistically significant difference was found in bond strength values in the tested group of post space pretreatment (p=0.564). Conclusions LAI using two erbium lasers, with PIPS or RFT2 tip, did not affect the bond strength of individually formed FRC posts to root canal dentin. PMID:28275279

  6. CO2 laser irradiation on vertical root fracture

    NASA Astrophysics Data System (ADS)

    Kfouri, Luciana Silva; Aun, Carlos E.; de Campos Ferraz, Jussara

    1997-05-01

    Vertical root fracture has been requested tooth extraction or root hemisection. There is no conservative treatment. The purpose of this paper was to analyze the CO2 laser effects on root fracture, associated with other materials. Forty two extracted human canines divided into 6 groups have their root vertically fractured. In groups A and B the CO2 laser was used with power of 5 W and 7 W respectively and the fracture line was covered with glass ionomer cement. In groups C and D the laser was used with 5 and 7 W and fracture line was covered with a dual composite. Groups E and F were controls, treated with glass ionomer cement and FLC dual composite. The teeth were placed in 5 percent methylene blue dye for 48 hs. The dye penetration was lowest in groups with glass ionomer cement and laser (A and B), at about (1.06mm). The difference between groups was statistically significant at 1 percent. All experimental groups showed dye penetration. The laser seemed to favor the sealing of the fracture line.

  7. Structural changes in the irradiated dentin with Nd:YAG and Er:YAG lasers for cervical hypersensitivity treatment and their influence on the microtensile resistance in resin-dentin interface

    NASA Astrophysics Data System (ADS)

    Mota, Cláudia C. B. O.; Sena, Tatiane V. N. S.; Castro, Roseane F.; Araújo, Ana C. S.; Gomes, Anderson S. L.

    2016-02-01

    This study aimed to evaluate, in vitro, the structural changes in dentin surfaces irradiated with Er:YAG (2940 nm, 90 mJ, 2 Hz, 300 μs, spot diameter 0.9 mm, 60 s/cm2, using the handpiece at 6 cm of distance to surface) and Nd:YAG (1064 nm, 1 W, 10 Hz, 300 μs, optical fiber diameter 300 μm, 60 s/cm2, using the handpiece at 2 mm of distance to surface) lasers to the treatment of cervical hypersensitivity and the respective bond strength compromising of resin composite restorations over these surfaces. 45 bovine teeth were selected, and removed the enamel portion of the buccal surface for laser irradiation and restorative procedure. Samples were divided into three groups: G1: control, only fluoride therapy; G2: irradiated with Er:YAG laser; G3: irradiated with Nd:YAG laser. Samples were submitted to optical coherence tomography analysis and subsequently they were restored with resin composite and sectioned into sticks for microtensile tests of achievement. ANOVA analysis of variance for the maximum force (N) and strength (MPa), with a significance level of 5% was performed. It was observed that G3 presented lower performance of maximum force (38,8 +/- 11,3 N) and resistance (26,0 +/- 9,3 MPa), and the G2 presented better results (51,0 +/- 13,5 N and 36,5 +/- 10,1 MPa), but still lower than those one obtained for G1 (56,0 +/- 12,3 N and 43,5 +/- 8,6 MPa). Although both lasers are effective in the cervical hypersensitivity treatment, when the aesthetic factor is the priority, the use of Er:YAG is preferable.

  8. Effect of chlorhexidine on bond strength between glass-fiber post and root canal dentine after six month of water storage.

    PubMed

    Toman, M; Toksavul, S; Tamaç, E; Sarikanat, M; Karagözoğlu, I

    2014-03-01

    Aim of this study was to assess the influence of chlorhexidine digluconate (CHX) application on bond strength of glass fibre reinforced composite (FRC) posts to root dentine using adhesive luting systems. Forty extracted human mandibular premolars were endodontically treated and root canals were prepared. Teeth were divided into 2 groups according to luting system as SuperBond C&B (etch-and-rinse/chemical cure) and FuturaBond DC (self-etch/ dual cure). Each group was further divided in 2 subgroups (n=10) according to whether CHX was applied or not. Group Futura/CHX: FuturaBond DC + CHX; group Futura: FuturaBond DC; group Super/CHX: Super Bond C&B + CHX; group Super: SuperBond C&B + CHX. Mean and standard deviation (in parenthesis) values of bond strength in MPa were: group Futura/CHX: 8.86 (1.96), group Futura: 7.65 (1.01), group Super/CHX: 17.47(2.93), group Super: 12.41 (3.83). Bond strength values were affected by the type of luting agent and CHX irrigation (p=0.001, two-way ANOVA). There were statistically significant differences among the groups according to one-way ANOVA (p<0.001). Significant differences were observed in bond strength between groups Super/CHX and Super (p=0.023), between groups Futura/CHX and Super/CHX (p<0.001). Application of CHX before luting procedure with etch-and-rinse/chemical cure luting agent of glass FRC post improved long-term bond strength between glass FRC and root dentine.

  9. Multi-step adhesive cementation versus one-step adhesive cementation: push-out bond strength between fiber post and root dentin before and after mechanical cycling.

    PubMed

    Amaral, Marina; Rippe, Marilia Pivetta; Bergoli, Cesar Dalmolin; Monaco, Carlo; Valandro, Luiz Felipe

    2011-01-01

    This study evaluated the effects of mechanical cycling on resin push-out bond strength to root dentin, using two strategies for fiber post cementation. Forty bovine roots were embedded in acrylic resin after root canal preparation using a custom drill of the fiber post system. The fiber posts were cemented into root canals using two different strategies (N = 20): a conventional adhesive approach using a three-step etch-and-rinse adhesive system combined with a conventional resin cement (ScotchBond Multi Purpose Plus + RelyX ARC ), or a simplified adhesive approach using a self-adhesive resin cement (RelyX U100). The core was built up with composite resin and half of the specimens from each cementation strategy were submitted to mechanical cycling (45 degree angle; 37 degrees C; 88 N; 4 Hz; 700,000 cycles). Each specimen was cross-sectioned and the disk specimens were pushed-out. The means from every group (n = 10) were statistically analyzed using a two-way ANOVA and a Tukey test (P = 0.05). The cementation strategy affected the push-out results (P < 0.001), while mechanical cycling did not (P = 0.3716). The simplified approach (a self-adhesive resin cement) had better bond performance despite the conditioning. The self-adhesive resin cement appears to be a good option for post cementation. Further trials are needed to confirm these results.

  10. Influence of Er:YAG and Ti:sapphire laser irradiation on the microtensile bond strength of several adhesives to dentin.

    PubMed

    Portillo, M; Lorenzo, M C; Moreno, P; García, A; Montero, J; Ceballos, L; Fuentes, M V; Albaladejo, A

    2015-02-01

    The aim of the present study was to evaluate the influence of erbium:yttrium-aluminum-garnet (Er:YAG) and Ti:sapphire laser irradiation on the microtensile bond strength (MTBS) of three different adhesive systems to dentin. Flat dentin surfaces from 27 molars were divided into three groups according to laser irradiation: control, Er:YAG (2,940 nm, 100 μs, 2.7 W, 9 Hz) and Ti:sapphire laser (795 nm, 120 fs, 1 W, 1 kHz). Each group was divided into three subgroups according to the adhesive system used: two-step total-etching adhesive (Adper Scotchbond 1 XT, from now on XT), two-step self-etching adhesive (Clearfil SE Bond, from now on CSE), and all-in-one self-etching adhesive (Optibond All-in-One, from now on OAO). After 24 h of water storage, beams of section at 1 mm(2) were longitudinally cut from the samples. Each beam underwent traction test in an Instron machine. Fifteen polished dentin specimens were used for the surface morphology analysis by scanning electron microscopy (SEM). Failure modes of representative debonded microbars were SEM-assessed. Data were analyzed by ANOVA, chi-square test, and multiple linear regression (p < 0.05). In the control group, XT obtained higher MTBS than that of laser groups that performed equally. CSE showed higher MTBS without laser than that with laser groups, where Er:YAG attained higher MTBS than ultrashort laser. When OAO was used, MTBS values were equal in the three treatments. CSE obtained the highest MTBS regardless of the surface treatment applied. The Er:YAG and ultrashort laser irradiation reduce the bonding effectiveness when a two-step total-etching adhesive or a two-step self-etching adhesive are used and do not affect their effectiveness when an all-in-one self-etching adhesive is applied.

  11. Effect of polymerization mode of two adhesive systems on push-out bond strength of fiber post to different regions of root canal dentin

    PubMed Central

    Ebrahimi, Shahram Farzin; Shadman, Niloofar; Nasery, Ehsan Baradaran; Sadeghian, Farid

    2014-01-01

    Background: A few studies have investigated the effect of the activation mode of adhesive systems on bond strength of fiber posts to root canal dentin. This study investigated the push-out bond strengths of a glass fiber post to different root canal regions with the use of two adhesives with light- and dual-cure polymerization modes. Materials and Methods: In this in vitro study, 40 maxillary central incisors were decoronated at cement-enamel junction with 15 ± 1 mm root length. After root canal therapy and post space preparations, they were randomly divided into four groups. Post spaces were treated with four different adhesives: Excite, Excite Dual cure Single Component (DSC), self-etch adhesive (AdheSE), and AdheSE dual-cure. Then the fiber-reinforced composite (FRC) post, Postec Plus, was cemented with dual-cure resin cement, Variolink II. The roots were cut into three 2-mm-thick slices. Push-out tests were performed with a universal testing machine at a crosshead speed of 0.5 mm/min. The mode of failures was determined under a stereomicroscope. Data were analyzed by three-way analysis of variance (ANOVA) and Tukey test was conducted to compare post hoc with P < 0.05 as the level of significance. Results: The highest bond strength was obtained for AdheSE dual-cure (15.54 ± 6.90 MPa) and the lowest was obtained for Excite light-cure (10.07 ± 7.45 MPa) and only the bond strength between these two adhesives had significant difference (P = 0.02). Bond strength decreased from the coronal to the apical in all groups and this was significant in Excite (group 1) and AdheSE (group 3) (P < 0.001). In apical regions, bond strength of dual-cure adhesives was significantly higher than light-cure adhesives (P < 0.001). Conclusion: Push-out bond strength of fiber post to different regions of root canal dentin was affected by both adhesive systems and their polymerization modes. PMID:24688557

  12. Comparative analysis of root surface smear layer removal by different etching modalities or erbium:yttrium-aluminum-garnet laser irradiation. A scanning electron microscopy study.

    PubMed

    Theodoro, Letícia Helena; Zezell, Denise Maria; Garcia, Valdir Gouveia; Haypek, Patrícia; Nagata, Maria José Hitomi; de Almeida, Juliano Milanezi; de Paula Eduardo, Carlos

    2010-07-01

    The purpose of this study was to evaluate the effect of erbium:yttrium-aluminum-garnet (Er:YAG) laser (2.94 mum) irradiation on the removal of root surface smear layer of extracted human teeth and to compare its efficacy with that of citric acid, ethylenediamine tetra-acetic acid (EDTA), or a gel containing a mixture of tetracycline hydrochloride (HCl) and citric acid, using scanning electron microscopy (SEM). Thirty human dentin specimens were randomly divided into six groups: G1 (control group), irrigated with 10 ml of physiologic saline solution; G2, conditioned with 24% citric acid gel; G3, conditioned with 24% EDTA gel; G4, conditioned with a 50% citric acid and tetracycline gel; G5, irradiated with Er:YAG laser (47 mJ/10 Hz/5.8 J/cm(2)/pulse); G6, irradiated with Er:YAG laser (83 mJ/10 Hz/10.3 J/cm(2)/pulse). Electron micrographs were obtained and analyzed according to a rating system. Statistical analysis was conducted with Kruskal-Wallis and Mann-Whitney tests (P < 0.05). G1 was statistically different from all the other groups; no statistically significant differences were observed between the Er:YAG laser groups and those undergoing the other treatment modalities. When the two Er:YAG laser groups were compared, the fluency of G6 was statistically more effective in smear layer removal than the one used in G5 (Mann-Whitney test, P < 0.01). Root surfaces irradiated by Er:YAG laser had more irregular contours than those treated by chemical agents. It can be concluded that all treatment modalities were effective in smear layer removal. The results of our study suggest that the Er:YAG laser can be safely used to condition diseased root surfaces effectively. Furthermore, the effect of Er:YAG laser irradiation on root surfaces should be evaluated in vivo so that its potential to enhance the healing of periodontal tissues can be assessed.

  13. Influence of multi-wavelength laser irradiation of enamel and dentin surfaces at 0.355, 2.94, and 9.4 μm on surface morphology, permeability, and acid resistance.

    PubMed

    Chang, Nai-Yuan N; Jew, Jamison M; Simon, Jacob C; Chen, Kenneth H; Lee, Robert C; Fried, William A; Cho, Jinny; Darling, Cynthia L; Fried, Daniel

    2017-07-12

    Ultraviolet (UV) and infrared (IR) lasers can be used to specifically target protein, water, and mineral, respectively, in dental hard tissues to produce varying changes in surface morphology, permeability, reflectivity, and acid resistance. The purpose of this study was to explore the influence of laser irradiation and topical fluoride application on the surface morphology, permeability, reflectivity, and acid resistance of enamel and dentin to shed light on the mechanism of interaction and develop more effective treatments. Twelve bovine enamel surfaces and twelve bovine dentin surfaces were irradiated with various combinations of lasers operating at 0.355 (Freq.-tripled Nd:YAG (UV) laser), 2.94 (Er:YAG laser), and 9.4 μm (CO2 laser), and surfaces were exposed to an acidulated phosphate fluoride gel and an acid challenge. Changes in the surface morphology, acid resistance, and permeability were measured using digital microscopy, polarized light microscopy, near-IR reflectance, fluorescence, polarization sensitive-optical coherence tomography (PS-OCT), and surface dehydration rate measurements. Different laser treatments dramatically influenced the surface morphology and permeability of both enamel and dentin. CO2 laser irradiation melted tooth surfaces. Er:YAG and UV lasers, while not melting tooth surfaces, showed markedly different surface roughness. Er:YAG irradiation led to significantly rougher enamel and dentin surfaces and led to higher permeability. There were significant differences in acid resistance among the various treatment groups. Surface dehydration measurements showed significant changes in permeability after laser treatments, application of fluoride and after exposure to demineralization. CO2 laser irradiation was most effective in inhibiting demineralization on enamel while topical fluoride was most effective for dentin surfaces. Lasers Surg. Med. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  14. Effect of silver diamine fluoride and ammonium hexafluorosilicate applications with and without Er:YAG laser irradiation on the microtensile bond strength in sound and caries-affected dentin.

    PubMed

    Kucukyilmaz, Ebru; Savas, Selcuk; Akcay, Merve; Bolukbasi, Basak

    2016-01-01

    Cariostatic and preventive agents are applied to create caries-resistant dentin surfaces and may affect subsequent resin bonding. The aim of this study was to investigate the effect of different agents with and without Er:YAG laser irradiation on the microtensile bond strength (µTBS) of resin composite to sound dentin (SD) and caries-affected dentin (CAD), and to assess the morphological and chemical changes in the specimens. Ninety-six extracted molar teeth were divided into a control group (deionized water) and two experimental groups (ammonium hexafluorosilicate [SiF], silver diamine fluoride [SDF]), that subdivided according to different conditions (SD, CAD, SD+laser irradiation, CAD+laser irradiation). After treatment procedures, the teeth were restored and the µTBS was tested with a universal testing machine. Morover, 144 teeth were prepared and after treatment modalities; morphological changes of the surface were investigated and elemental analyses were performed using scanning electron microscope/energy dispersive spectroscopy (SEM-EDS). The data were analyzed using Kruskal-Wallis and Mann-Whitney U tests. SDF and SiF applications reduced the µTBS values in both the SD and CAD subgroups (P < 0.05). Laser irradiation increased the µTBS values in the SiF group and the values were adversely affected in the SDF group (P < 0.05). Fluoride content of the specimens increased in all of the treatment groups, compared with the control group. Silver content was detected only in the SDF group, and silicon was detected only in the SiF group. The µTBS values of resin composite, surface morphology and chemical characteristics of dentin were affected by the material type, dentin condition and laser irradiation and the use of SiF and SDF solutions under the resin restorations do not seem appropriate. © 2016 Wiley Periodicals, Inc.

  15. Stress distribution on dentin-cement-post interface varying root canal and glass fiber post diameters. A three-dimensional finite element analysis based on micro-CT data

    PubMed Central

    LAZARI, Priscilla Cardoso; de OLIVEIRA, Rodrigo Caldeira Nunes; ANCHIETA, Rodolfo Bruniera; de ALMEIDA, Erika Oliveira; FREITAS JUNIOR, Amilcar Chagas; KINA, Sidney; ROCHA, Eduardo Passos

    2013-01-01

    Objective The aim of the present study was to analyze the influence of root canal and glass fiber post diameters on the biomechanical behavior of the dentin/cement/post interface of a root-filled tooth using 3D finite element analysis. Material and Methods Six models were built using micro-CT imaging data and SolidWorks 2007 software, varying the root canal (C) and the glass fiber post (P) diameters: C1P1-C=1 mm and P=1 mm; C2P1-C=2 mm and P=1 mm; C2P2-C=2 mm and P=2 mm; C3P1-C=3 mm and P=1 mm; C3P2-C=3 mm and P=2 mm; and C3P3-C=3 mm and P=3 mm. The numerical analysis was conducted with ANSYS Workbench 10.0. An oblique force (180 N at 45º) was applied to the palatal surface of the central incisor. The periodontal ligament surface was constrained on the three axes (x=y=z=0). Maximum principal stress (σmax) values were evaluated for the root dentin, cement layer, and glass fiber post. Results: The most evident stress was observed in the glass fiber post at C3P1 (323 MPa), and the maximum stress in the cement layer occurred at C1P1 (43.2 MPa). The stress on the root dentin was almost constant in all models with a peak in tension at C2P1 (64.5 MPa). Conclusion The greatest discrepancy between root canal and post diameters is favorable for stress concentration at the post surface. The dentin remaining after the various root canal preparations did not increase the stress levels on the root. PMID:24473716

  16. Stress distribution on dentin-cement-post interface varying root canal and glass fiber post diameters. A three-dimensional finite element analysis based on micro-CT data.

    PubMed

    Lazari, Priscilla Cardoso; Oliveira, Rodrigo Caldeira Nunes de; Anchieta, Rodolfo Bruniera; Almeida, Erika Oliveira de; Freitas Junior, Amilcar Chagas; Kina, Sidney; Rocha, Eduardo Passos

    2013-01-01

    The aim of the present study was to analyze the influence of root canal and glass fiber post diameters on the biomechanical behavior of the dentin/cement/post interface of a root-filled tooth using 3D finite element analysis. Six models were built using micro-CT imaging data and SolidWorks 2007 software, varying the root canal (C) and the glass fiber post (P) diameters: C1P1-C=1 mm and P=1 mm; C2P1-C=2 mm and P=1 mm; C2P2-C=2 mm and P=2 mm; C3P1-C=3 mm and P=1 mm; C3P2-C=3 mm and P=2 mm; and C3P3-C=3 mm and P=3 mm. The numerical analysis was conducted with ANSYS Workbench 10.0. An oblique force (180 N at 45º) was applied to the palatal surface of the central incisor. The periodontal ligament surface was constrained on the three axes (x=y=z=0). Maximum principal stress (σ(max)) values were evaluated for the root dentin, cement layer, and glass fiber post. The most evident stress was observed in the glass fiber post at C3P1 (323 MPa), and the maximum stress in the cement layer occurred at C1P1 (43.2 MPa). The stress on the root dentin was almost constant in all models with a peak in tension at C2P1 (64.5 MPa). The greatest discrepancy between root canal and post diameters is favorable for stress concentration at the post surface. The dentin remaining after the various root canal preparations did not increase the stress levels on the root.

  17. Effect of gamma irradiation on the antimicrobial and free radical scavenging activities of Glycyrrhiza glabra root

    NASA Astrophysics Data System (ADS)

    Fatima Khattak, Khanzadi; James Simpson, Thomas

    2010-04-01

    The efficacy of gamma irradiation as a method of decontamination for food and herbal materials is well established. In the present study, Glycyrrhiza glabra roots were irradiated at doses 5, 10, 15, 20 and 25 kGy in a cobalt-60 irradiator. The irradiated and un-irradiated control samples were evaluated for phenolic contents, antimicrobial activities and DPPH scavenging properties. The result of the present study showed that radiation treatment up to 20 kGy does not affect the antifungal and antibacterial activity of the plant. While sample irradiated at 25 kGy does showed changes in the antibacterial activity against some selected pathogens. No significant differences in the phenolic contents were observed for control and samples irradiated at 5, 10 and 15 kGy radiation doses. However, phenolic contents increased in samples treated with 20 and 25 kGy doses. The DPPH scavenging activity significantly ( p<0.05) increased in all irradiated samples of the plant.

  18. Optimal irradiation condition of demineralized dentin treatment with a nanosecond pulsed laser at 5.8 μm wavelength range

    NASA Astrophysics Data System (ADS)

    Ishii, Katsunori; Saiki, Masayuki; Kita, Tetsuya; Yoshikawa, Kazushi; Yasuo, Kenzo; Yamamoto, Kazuyo; Awazu, Kunio

    2012-06-01

    Conventional dental lasers have not realized a selective excavation of carious dentin. Objective of this study is to determine the optimal irradiation condition for the selective excavation by using a wavelength around 5.8 μm. A nanosecond pulsed laser with a wavelength of 5.8 μm was obtained by difference-frequency generation technique. The laser delivers 5 ns pulse width at a repetition rate of 10 Hz. 5.8 μm wavelength range, a short wavelength required high excavation energy and a long wavelength required low excavation energy to induce the selective excavation with a low thermal side effect. 5.8 μm wavelength provides a selective excavation technique for minimal intervention.

  19. Evaluation of Intra Root Canal Er,Cr:YSGG Laser Irradiation on Prosthetic Post Adherence.

    PubMed

    Quinto, Jose; Amaral, Marcello Magri; Francci, Carlos Eduardo; Ana, Patricia Aparecida; Moritz, Andreas; Zezell, Denise Maria

    2017-03-03

    In clinical prosthetics procedures, including endodontics and post fixation, the presence of a smear layer can reduce the post bond strength. An Er,Cr:YSGG laser, which emits at 2780 nm, can promote a smear-layer-free surface due to the ablation process. Considering these aspects, the purpose of this work was to evaluate the influence of Er,Cr:YSGG laser irradiation using either a radial or an axial fiber tip on the bond strength of three resin cements to the fiber-reinforced composite posts. Ninety recently extracted single rooted human teeth had their root canal instrumented and were randomly distributed into nine experimental groups, in which three resin cements (total-etching Variolink II, self-etching Panavia F, and self-adhesive RelyX Unicem Aplicap) and three root canal treatments (no treatment, laser irradiation using the radial fiber tip, laser irradiation using the axial fiber tip) were used. Specimens were then sectioned into three sections (cervical, middle, and apical thirds) with two slices on each section. A push-out test was performed on each slice, and the values were recorded as MPa. The push-out data were analyzed by a Ryan-Joiner normality test followed by a two-way ANOVA test and Tukey pairwise comparison. The statistical analysis was performed on each third section separately, with a 5% significance level. Laser irradiation with axial fiber tip significantly increased the post bond strength of RelyX Unicem Aplicap on middle third of specimens (p < 0.001) when compared to other root canal treatments (unlased or irradiated with radial tip). Considering the Panavia resin cement, laser irradiation with either axial or radial tips promoted a significant increase on the post bond strength of middle third when compared to unlased specimens (p < 0.001); however, laser irradiation did not influence the post bond strength of Variolink resin cement. The use of the Er,Cr:YSGG laser for clinical prosthetics procedures enhances the post bond strength of

  20. Evaluating the Effect of CPP-ACP as a Final Irrigant in Improving the Micro-Hardness of Erosive Root Dentin and its Influence on the Bond Strength of Self Etch Resin Sealer – An In-vitro Study

    PubMed Central

    Bollineni, Swetha; Janga, Ravi Kumar; Saraswati, Disha; Babu, Mandava Ramesh

    2016-01-01

    Introduction Smear layer removal from the root canal wall involves the use of 17% EDTA and 5.25% sodium hypochlorite, which thereby improves the adhesion of obturating materials to root dentin. But these chemical irrigants have shown to decrease micro hardness, increase roughness, cause erosion and reduce the root dentin fracture toughness. To combat these adverse effects, studies can be focussed on the remineralisation of the erosive root dentin and this novel idea has been utilized in the present study. Aim To evaluate the micro hardness of erosive root dentin when Casein Phosphopeptide–Amorphous Calcium Phosphate (CPP-ACP) was used as a final irrigant and its influence on resin sealer bonding tested by push-out bond strength method. Materials and Methods Sixty extracted maxillary incisors were divided into three groups based on the final irrigation protocol. Group 1-normal saline, Group 2-17% EDTA (Ethylene Diamine Tetraacetic Acid) + 5.25% NaOCl (Sodium Hypochlorite), Group 3 - 17% EDTA + 5.25% NaOCl + CPP-ACP; each group was divided into two subgroups. Half the specimens of each group were evaluated for Vicker’s micro hardness test after the treatment. In continuation with the above methodology the remaining specimens were tested for push-out bond strength after obturation of the specimens with self etch adhesive resin sealer and conventional 6% gutta percha cones. Results Micro hardness was statistically analysed using Kruskal Wallis test and push-out bond strength was evaluated using Mann Whitney test and paired t-test. CPP-ACP treated group showed increased micro hardness (p<0.05). There was no statistically significant difference between the push-out bond strength values between group EDTA + NaOCl group and EDTA + NaOCl + CPP-ACP group. Conclusion Within the limitations of this study it can be concluded that, CPP-ACP improved the micro hardness of erosive root dentin and is not affecting its bond strength. Therefore, CPP-ACP may be used before bonding

  1. [Effects of Nd: YAG laser irradiation on the root surfaces and adhesion of Streptococcus mutans].

    PubMed

    Yuanhong, Li; Zhongcheng, Li; Mengqi, Luo; Daonan, Shen; Shu, Zhang; Shu, Meng

    2016-12-01

    This study aimed to evaluate the effects of treatment with different powers of Nd: YAG laser irradiation on root surfaces and Streptococcus mutans (S. mutans) adhesion. Extracted teeth because of severe periodontal disease were divided into the following four groups: control group, laser group 1, laser group 2, and laser group 3. After scaling and root planning, laser group 1, laser group 2, and laser group 3 were separately treated with Nd: YAG laser irradiation (4/6/8 W, 60 s); however, the control group did not receive the treatment. Scanning electron microscopy (SEM) was used to determine the morphology. S. mutans were cultured with root slices from each group. Colony forming unit per mL (CFU·mL⁻¹) was used to count and compare the amounts of bacteria adhesion among groups. SEM was used to observe the difference of bacteria adhesion to root surfaces between control group (scaling) and laser group 2 (6 W, 60 s), thereby indicating the different bacteria adhesions because of different treatments. Morphology alterations indicated that root surfaces in control group contain obvious smear layer, debris, and biofilm; whereas the root surfaces in laser group contain more cracks with less smear layer and debris. The bacteria counting indicated that S. mutans adhesion to laser group was weaker than that of control group (P<0.05). No statistical significance among the laser groups (P>0.05) was observed. Morphology alterations also verified that S. mutans adhesion to laser group 2 (6 W, 60 s) was weaker than that of control group (scaling). This study demonstrated that Nd: YAG laser irradiation treatment after scaling can reduce smear layer, debris, and biofilm on the root surfaces as compared with conventional scaling. The laser treatment reduces the adhesion of S. mutans as well. However, Nd: YAG laser irradiation can cause cracks on the root surfaces. In this experiment, the optimum laser power of 6 W can thoroughly remove the smear layer and debris, as well as

  2. Dentinal Microcracks After Root Canal Preparation” A Comparative Evaluation with Hand, Rotary and Reciprocating Instrumentation

    PubMed Central

    Chandrasekhar, Veeramachaneni; Anita, S.; Tummala, Muralidhar; Raj, T.B. Phanindhar; Badami, Vijetha; Kumar, Pradeep; Soujanya, E.

    2014-01-01

    Introduction: The purpose of this study was to compare the incidence of dentinal micro cracks after instrumentation with various types of NiTi files in rotary and reciprocating motion. Materials and Methods: One hundred human extracted mandibular central incisors were taken and divided into 10 groups (n=10 teeth per group). Group 1- No preparation, Group 2 – Hand instrumentation, Groups 3,4 - ProTaper files in rotary and reciprocating motion, Groups 5,6 - ProTaper Next files in rotary and reciprocating motion, Groups 7,8 – Oneshape files in rotary and reciprocating motion, Groups 9,10 – Reciproc files in rotary and reciprocating motion. Specimens were sectioned horizontally at 3,6 and 9 mm from the apex and dentinal micro cracks were observed under a stereomicroscope. Results: There was a statistically significant difference between the groups (p<0.05). There were no significant differences in crack formation between the groups (Protaper Next - Rot, Protaper Next - Rec, Reciproc – Rec); (ProTaper - Rot, ProTaper - Rec, Oneshape – Rot), (Oneshape – Rot, Reciproc – Rot), (One shape Reciproc, Reciproc – Rec); (p >.05). Conclusion: Least cracks were seen in canals instrumented with Pro Taper Next files both in rotary and reciprocating motion. Full sequence rotary systems showed less cracks than single file systems and full sequence rotary systems showed less cracks in reciprocating motion than in rotary motion. PMID:25654036

  3. Effect of adhesive system type and root region on the push-out bond strength of glass-fibre posts to radicular dentine.

    PubMed

    Onay, E O; Korkmaz, Y; Kiremitci, A

    2010-04-01

    To compare interfacial strength in different thirds of the root canal amongst glass-fibre posts luted with four different adhesive luting agents. A total of 44 extracted human single-rooted teeth were randomly divided in four groups and restored using glass-fibre posts and the following luting agents: All Bond SE/Duo-Link (ABSE), All Bond 3/Duo-Link (AB3), BisCem (BC), Clearfil ED primer II/Clearfil Esthetic Cement (CLF). One week after luting, the samples were thermocycled in water, and then embedded in acrylic resin. Three sections (cervical, middle and apical) of 2 mm thickness were prepared from each specimen, and the post in each section was subjected to a push-out test. One additional specimen for each group was prepared for scanning electron microscopy analysis and the bonding effectiveness to dentine was assessed. The data were analysed using the Kolmogorov-Smirnov test, two-way anova, one-way anova, and the Scheffe test (P < 0.05). The push-out bond strength values for BC and ABSE were not significantly different (P > 0.05), but both were significantly higher than the means for AB3 and CLF (P < 0.05) in the cervical and middle regions. The same trend was observed in the apical region, except for the AB3 and ABSE which were not significantly different (P > 0.05) from each other. There were significant differences in bond strength amongst root thirds, with a reduction in values from the cervical to apical third (P < 0.05). The use of BisCem and All Bond SE/Duo-Link combination with their simplified application procedures may be considered an alternative to the currently used systems for luting glass-fibre posts in root canal.

  4. Comparing irradiation parameters on disinfecting enterrecoccus faecalis in root canal disinfection

    NASA Astrophysics Data System (ADS)

    Sarp, Ayşe. S.; Gülsoy, Murat

    2016-02-01

    Although conventional method carries all the debris, studies on persisting infections in root canals show bacteria and their toxins spread from the root canal and contaminate the apical region. Thus developes apical periodontitis or symptoms, and loss of tooth. Even if the treatment has adequate success, anatomy of root canal system can be very complexwith accessory canals. The disinfecting effect of laser radiation has only recently been used in dentistry. Laser irradiation has a bactericidal effect. Each wavelength has its own advantages and limitations according to their different absorption characteristics, depending on their 'absorption coefficient'. The sterilizing efficiency of two types of wavelengths, a new fiber laser 1940- nm Thulium fiber Laser and an 2940 nm Er:YAG Laser were compared in this study. Irradiation with a power of 0.50 W with 1940- nm Thulium fiber Laser disinfected 95,15% of bacteria, however irradiation with same laser power with Er:YAG Laser caused a reduction of 96,48 %. But there was no significant difference in the disinfection effect of two different laser groups ( p < 0.05, Mann- U-Whitney Test). In addition to this, Er :YAG Laser caused three times more reduction from its own positive control group where 1940- nm Thulium fiber Laser caused 2,5 times effective disinfection.

  5. Effects of 980-nm diode laser on the ultrastructure and fracture resistance of dentine.

    PubMed

    Faria, Maria Isabel Anastacio; Sousa-Neto, Manoel Damião; Souza-Gabriel, Aline Evangelista; Alfredo, Edson; Romeo, Umberto; Silva-Sousa, Yara Teresinha Correa

    2013-01-01

    Few reports have addressed the effects of diode laser irradiation at 980 nm on the morphology and fracture resistance of dentine. The purpose of this study is to evaluate the effects of 980-nm diode laser on the ultrastructure and fracture resistance of root dentine. The roots of 90 extracted canine teeth were divided into three groups according to the type of irrigating solution (water, NaOCl, and NaOCl/EDTA) and subdivided into three subgroups (n = 10) according to the amount of laser irradiation (without irradiation, 1.5 W/100 Hz and 3.0 W/100 Hz). The roots were filled with an epoxy resin-based sealer and gutta-percha and then subjected to a fracture resistance test. Data were analyzed by ANOVA and the Tukey test (p < 0.05). Additionally, 18 canine teeth were prepared using the same irrigation/irradiation protocols and evaluated by scanning electron microscopy (SEM). The SEM showed greater changes when the laser power increased, and the changes also varied according to the irrigating solution. A modified smear layer was observed in specimens that were treated with water and then laser-irradiated. The laser treatment did not alter the fracture resistance of roots treated with 1.5 W/100 Hz (246.3 ± 29.5 N) and 3.0 W/100 Hz (215.3 ± 25.1 N) laser power. The roots treated with NaOCl were more susceptible to fracture (199.4 ± 15.1 N) than those irrigated with water (254.2 ± 23.0 N) (p < 0.05). The 980-nm diode laser altered the morphology of the dentine but did not affect the fracture resistance of the roots.

  6. Role of surface tension and roughness on the wettability of Er:YAG laser irradiated dentin: In vitro study

    PubMed Central

    Brulat, Nathalie; Rocca, Jean-Paul; Darque-Ceretti, Evelyne

    2013-01-01

    Introduction: The aim of this “in vitro” study was to evaluate the role of surface tension and surface roughness in the wettability, considered essential for a good adhesion, comparing Er:YAG laser - to bur-prepared dentin. Materials and Methods: Dentin surfaces of third human molars were Er:YAG laser- and bur-prepared to evaluate the effects of surface tension and roughness on wettability and interferometric analysis was used to compare the roughness of the two groups surfaces, after gold-coating them. Results: In bur-prepared samples the time taken for the water drop to spread out was approximately the same with or without metallization while, in the Er:YAG laser-prepared surfaces the spreading-out time was less than 10 seconds but longer after metallization i.e. nearly two minutes. Large differences in wettability measurements were observed because the water drop was almost immediately absorbed on the Er:YAG laser-prepared surface. The wettability test demonstrated that the porous and hydrophilic properties of Er:YAG laser-prepared surfaces are higher than bur-prepared surfaces. Conclusion: Surface tension, surface morphology and porosity had different effects on the spreading time of a water drop on both Er:YAG laser- and bur-prepared surfaces. And, while surface tension does not seem to influence the results, roughness appears to be the main parameter involved in water drop spreading, this being an indication, by the clinical point of view, to the choice of Er:YAG laser parameters in conservative dentistry. PMID:24204092

  7. Influence of CVD diamond tips and Er:YAG laser irradiation on bonding of different adhesive systems to dentin.

    PubMed

    da Silva, Melissa Aline; Di Nicolo, Rebeca; Barcellos, Daphne Camara; Batista, Graziela Ribeiro; Pucci, Cesar Rogerio; Rocha Gomes Torres, Carlos; Borges, Alessandra Bühler

    2013-01-01

    The aim of this study was to compare the microtensile bond strength of three adhesive systems, using different methods of dentin preparation. A hundred and eight bovine teeth were used. The dentin from buccal face was exposed and prepared with three different methods, divided in 3 groups: Group 1 (DT)- diamond tip on a high-speed handpiece; Group 2 (CVD)-CVD tip on a ultrasonic handpiece; Group 3 (LA)-Er: YAG laser. The teeth were divided into 3 subgroups, according adhesive systems used: Subgroup 1-Adper Single Bond Plus/3M ESPE (SB) total-etch adhesive; Subgroup 2-Adper Scotchbond SE/3M ESPE (AS) selfetching adhesive; Subgroup 3-Clearfil SE Bond/Kuraray (CS) selfetching adhesive. Blocks of composite (Filtek Z250-3M ESPE) 4 mm high were built up and specimens were stored in deionized water for 24 hours at 37°C. Serial mesiodistal and buccolingual cuts were made and stick-like specimens were obtained, with transversal section of 1.0 mm(2). The samples were submitted to microtensile test at 1 mm/min and load of 10 kg in a universal testing machine. Data (MPa) were subjected to ANOVA and Tukey's tests (p < 0.05). Surface treatment with Diamond or CVD tips associated with Clearfil SE Bond adhesive produced significantly lower bond strength values compared to other groups. Surface treatment with Er: YAG laser associated with Single Bond Plus or Clearfil SE Bond adhesives and surface treatment with CVD tip associated with Adper Scotchbond SE adhesive produced significantly lower bond strength values compared to surface treatment with diamond or CVD tips associated with Single Bond Plus or Adper Scotchbond SE adhesives. Interactions between laser and the CVD tip technologies and the different adhesive systems can produce a satisfactory bonding strength result, so that these associations may be beneficial and enhance the clinical outcomes.

  8. Retentive strength of fiber-reinforced composite posts with composite resin cores: Effect of remaining coronal structure and root canal dentin conditioning protocols.

    PubMed

    Saker, Samah; Özcan, Mutlu

    2015-12-01

    The prognosis of a fixed dental prosthesis cemented to endodontically treated teeth is primarily determined by the presence of a ferrule on the tooth. Adhesion of the post in the root canal, conditioning methods for the canal and the amount of coronal structure could also be decisive on survival of reconstructions cemented on endodontically treated teeth. The purpose of this in vitro study was to test the effect of remaining coronal structure on the retention of airborne-particle abraded fiber-reinforced composite resin posts built up with composite resin cores after the treatment of root canal dentin with different conditioning protocols. One hundred and fifty extracted human teeth with single root canal space were endodontically treated and divided into 3 groups as follows: group CEJ: the teeth were sectioned at the level of cementoenamel junction (CEJ); group CEJ1: the teeth were sectioned 1 mm above the CEJ; group CEJ2: the teeth were sectioned 2 mm above the CEJ. Each group was further divided into 5 subgroups (n=10 per group) according to the root canal treatments as follows: group C: no conditioning (control); group PH: conditioning with 37% phosphoric acid gel for 15 seconds; group E: conditioning with 17% ethylenediaminetetraacetic acid (EDTA) for 60 seconds; group CHX: conditioning with 2% chlorhexidine (CHX) for 60 seconds; group Q: conditioning with combination of 2% CHX with 17% EDTA and a surfactant solution for 60 seconds. Glass fiber-reinforced composite resin posts were airborne-particle abraded and luted to the root canal dentin with a self-adhesive resin cement (RelyX Unicem). The retentive force was tested by applying a tensile load parallel to the long axis of these posts at a crosshead speed of 2 mm/min. Two-way ANOVA and the Tukey HSD post hoc test were used to analyze the data. The highest retention (N) was obtained with the CHX-EDTA conditioned group (374.7 ±29.8) followed by 17% EDTA (367.9 ±33.3) conditioning when 2 mm remaining

  9. Treatment of tooth fracture by medium energy CO2 laser and DP-bioactive glass paste: thermal behavior and phase transformation of human tooth enamel and dentin after irradiation by CO2 laser.

    PubMed

    Lin, C P; Lee, B S; Kok, S H; Lan, W H; Tseng, Y C; Lin, F H

    2000-06-01

    Acute trauma or trauma associated with occlusal disharmony can produce tooth crack or fracture. Although several methods are proposed to treat the defect, however, the prognosis is generally poor. If the fusion of a tooth fracture by laser is possible it will offer an alternative to extraction or at least serve as an adjunctive treatment in the reconstruction. The responses of soft tissues to lasers of different wavelengths are fairly well known, but the reactions of hard tissues are still to be understood. The purpose of this research was to study the feasibility of using a medium energy continuous-wave CO(2) laser and a low melting-point bioactive glass to fuse or bridge tooth fractures. The present report is focused on the first part of the research, the analysis of changes in laser-irradiated human tooth enamel/dentin by means of X-ray diffractometer (XRD), Fourier-transforming infrared spectroscopy (FTIR), differential thermal analysis/thermogravimetric analysis (DTA/TGA), and scanning electron microscopy (SEM). After CO(2) laser irradiation, there were no marked changes in the X-ray diffraction pattern of the enamel when compared to that before laser treatment. However, a small peak belonging to alpha-TCP appeared at the position of 2theta=30.78 degrees C. After being treated with CO(2) laser, the dentin showed much sharper peaks on the diffraction patterns because of grain growth and better crystallinity. alpha-TCP and beta-TCP were identified after laser treatment. In the FTIR analysis, an HPO(4)(-2) absorption band was noted before laser treatment disappeared after the irradiation. No significant change in the absorption band of HPO(4)(-2) was found on the FTIR curves of enamel after laser treatment. The results of DTA/TGA indicated that loss of water and organic materials occurred in both enamel and dentin after laser treatment. Under SEM, melting and resolidification occurred in both enamel and dentin by medium energy of CO(2) laser. This implies that

  10. Imaging natural and artificial demineralization on dentin surfaces with polarization sensitive optical coherence tomography

    PubMed Central

    Manesh, Saman K.; Darling, Cynthia L.; Fried, Daniel

    2011-01-01

    The purpose of this study was to assess the potential of polarization sensitive optical coherence tomography (PS-OCT) to measure non-destructively the severity of natural and artificial caries lesions in dentin and determine the efficacy of intervention with anti-caries agents. Although several studies have demonstrated the utility of PS-OCT to image caries lesions in enamel and to quantify the lesion severity, only a few studies have focused on lesions in dentin. In this study images of natural root caries lesions on extracted human teeth were acquired with PS-OCT. In addition artificial lesions were produced in dentin after 12 days of exposure to a demineralization solution at a pH of 5.0. Before exposure, three incisions were made on the sample surfaces using Er:YAG laser irradiation and selected areas were treated with topical fluoride. PS-OCT images were acquired using a high power (45-mw) 1310-nm superluminescent diode with a bandwidth of 35-nm. PS-OCT was able to measure demineralization in dentin to a depth of ~ 1 mm. Polarized light microscopy and microradiography were used to measure lesion severity on histological thin sections for comparison. PS-OCT successfully measured the inhibition of demineralization by topical fluoride. Er:YAG laser irradiation did not significantly increase or decrease the rate of dentin demineralization. PMID:21998492

  11. Imaging natural and artificial demineralization on dentin surfaces with polarization sensitive optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Manesh, Saman K.; Darling, Cynthia L.; Fried, Daniel

    2008-02-01

    The purpose of this study was to assess the potential of polarization sensitive optical coherence tomography (PS-OCT) to measure non-destructively the severity of natural and artificial caries lesions in dentin and determine the efficacy of intervention with anti-caries agents. Although several studies have demonstrated the utility of PS-OCT to image caries lesions in enamel and quantify the lesion severity, only a few studies have focused on lesions in dentin. In this study images of natural root caries lesions on extracted human teeth were acquired with PS-OCT. In addition artificial lesions were produced in dentin after 12 days of exposure to a demineralization solution at a pH of 5.0. Before exposure, three incisions were made on the sample surfaces using Er:YAG laser irradiation and selected areas were treated with topical fluoride. PS-OCT images were acquired using a high power (45-mw) 1310-nm superluminescent diode with a bandwidth of 35-nm. PS-OCT was able to measure demineralization in dentin to a depth of ~ 1 mm. Polarized light microscopy and microradiography were used to measure lesion severity on histological thin sections for comparison. PS-OCT successfully measured the inhibition of demineralization by topical fluoride. Er:YAG laser irradiation did not significantly increase or decrease the rate of dentin demineralization.

  12. Antimicrobial effect of Er:YAG laser irradiation in infected root canals: an in vitro study

    NASA Astrophysics Data System (ADS)

    Sampaio Moura, Marcelo; Zanin, Fatima A. A.; Brugnera, Aldo, Jr.; Rodrigues de Araujo Estrela, Cyntia; Estrela, Carlos; Djalma Pecora, Jesus

    2003-06-01

    This study evaluated in vitro the antimicrobial action of Er:YAG laser in infected root canals. A total of 36 human anterior teeth were prepared, sterilized and inoculated with suspensions of S. aureus, E. faecalis, P aeruginosa, B. subtilis and C. albicans. After the contamination period (28 days), the teeth were irrigated with sterile distilled water or 1% sodium hypochlorite and, then, irradiated with an Er:YAG laser (wavelength 2094 nm) with two different evaluation parameters: 52 mJ and 110 mJ laser output at the fiber tip. After the irradiation, the teeth were irrigated with sterile distilled water and the solutions were collected with sterile paper points and incubated in Letheen Broth for 48 hours. After this period 0,1 ml of this solution was transferred to 10 ml of Brain Heart Infusion and incubated for 48 hours. After 72 hours a new collect ion was done and incubated again. Based on the data, it was concluded that the distilled water or 1% sodium hypochlorite irradiated or not with an Er:YAG laser with two different parameters: 10 Hz, 110 mJ input and 52 mJ output, and 10 Hz, 250 mJ input and 110 mJ output had no antimicrobial activity in the root canals contaminated with the following microorganisms: Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis and Candida albicans.

  13. Induction of micronuclei in germinating onion seed root tip cells irradiated with high energy heavy ions.

    PubMed

    Takatsuji, Toshihiro; Takayanagi, Hiroki; Morishita, Kana; Nojima, Kumie; Furusawa, Yoshiya; Nakazawa, Yuka; Matsuse, Michiko; Akamatsu, Sakura; Hirano, Natsuko; Hirashima, Natsuko; Hotokezaka, Saori; Ijichi, Toyomi; Kakimoto, Chika; Kanemaru, Tomomi; Koshitake, Mayumi; Moriuchi, Akiko; Yamamoto, Kensuke; Yoshikawa, Isao

    2010-01-01

    Effects of high LET charged particles on a perfect in-vivo system are an essential theme for the study of the biological effects of radiation. Germinating onion seeds are independent complete organisms and the radiation induced micronuclei in the root chip cells can be examined quantitatively and theoretically. We irradiated with three types of high energy accelerated heavy ions germinating onion seeds using a synchrotron and observed micronuclei in the root tip cells. Micronuclei induction showed characteristic dose responses of an upward convex bell shape and a steep rise near zero doses for all types of the ions. The bell curve dose responses, however, could be explained by a simple mathematical model. A parameter in the model which indicates micronuclei induction frequency and another parameter which indicates induction frequency of lethal damages (or damages delaying cell divisions) per heavy ion track were both proportional to square of the LET. Because we suspected by-stander effect concerning the dose responses rising steeply near zero doses and tapering off for higher doses, we tested acute irradiation to remove time of information transmittance between cells using a single spill (about 0.3 s) of the synchrotron beam. No difference was detected between normal multiple spill irradiations and single spill.

  14. Evaluation of absorbed dose in irradiated sugar-containing plant material (peony roots) by an ESR method

    NASA Astrophysics Data System (ADS)

    Yamaoki, Rumi; Kimura, Shojiro; Ohta, Masatoshi

    2015-12-01

    The relationship between electron spin resonance (ESR) signal intensity of irradiated plant materials and sugar content was investigated by spectral analysis using peony roots. A weak background signal near g=2.005 was observed in the roots. After a 10 kGy irradiation, the ESR line broadened and the intensity increased, and the spectral characteristics were similar to a typical spectrum of irradiated food containing crystalline sugars. The free radical concentration was nearly stable 30 days after irradiation. The spectrum of peony root 30 days after irradiation was simulated using the summation of the intensities of six assumed components: radical signals derived from (a) sucrose, (b) glucose, (c) fructose, (d) cellulose, (e) the background signal near g=2.005 and (f) unidentified component. The simulated spectra using the six components were in agreement with the observed sample spectra. The intensity of sucrose radical signal in irradiated samples increased proportionally up to 20 kGy. In addition, the intensity of sucrose radical signals was strongly correlated with the sucrose contents of the samples. The results showed that the radiation sensitivity of sucrose in peony roots was influenced little by other plant constituents. There was also a good correlation between the total area of the spectra and the sucrose content, because the sucrose content was higher than that of other sugars in the samples. In peony roots, estimation of the absorbed dose from the ESR signal intensity may be possible by a calibration method based on the sucrose content.

  15. Inelastic deformation and microcracking process in human dentin.

    PubMed

    Eltit, Felipe; Ebacher, Vincent; Wang, Rizhi

    2013-08-01

    Dentin is a mineralized collagen tissue with robust mechanical performance. Understanding the mechanical behavior of dentin and its relations to the dentinal structure can provides insight into the design strategies to achieve tooth functions. This study focuses on the inelastic deformation of human dentin and its underlying mechanisms. By combining four-point bending tests with fluorescent staining and laser scanning confocal microscopy, it was found that human dentin, especially root dentin, exhibited significant inelastic deformation and developed extensive microdamage in the form of microcracks prior to fracture. Dense and wavy microcracks spread uniformly across the tensile surface of root dentin, while compressive microcracks formed cross-hatched patterns. The presence of peritubular dentin in coronal dentin dramatically decreased the extent of microcracking, reducing inelasticity. Dentinal tubules were found to be initiation sites of both tensile and compressive microcracks. A unique crack propagation process was observed in root dentin under tension: numerous ring-shaped cracks formed at each dentinal tubule ahead of a growing crack tip. The advance of the tensile microcracks occurred by the merging of those ring-shaped cracks. The current findings on the microcracking process associated with inelastic deformation helps to understand the nature of strength and toughness in dentin, as well as the mechanical significance for structural variations across the whole tooth.

  16. Comparative effect of irradiation and heating on the microbiological properties of licorice (Glycyrrhiza glabra L.) root powders.

    PubMed

    Al-Bachir, M; Al-Adawi, M

    2015-01-01

    To determine the effect of gamma irradiation, steaming and heating on microbial load and chemical composition of licorice root powder. Powders were exposed to hot air treatment at 60°C for 24 h, steaming at 1.1 bar and about 121°C for 15 min, and irradiation at 10 kGy using a (60)Co source. Microbial load, moisture, ash, and electrical conductivity (EC) values of licorice root powders were evaluated immediately after treatment, and after 12 months of storage. Total aerobic plate count (TAPC) of licorice roots powder (control sample), including coliform, Escherichia coli, and Klebsiella spp. were relatively high. Irradiation reduced the TAPC by 4 logs and total coliform to negative (less than 1 log(10) colony forming units (CFU) g(-1)) Klebsiella spp., E. coli, and Salmonella spp. were not detected (less than 1 log(10) CFU/g) in irradiated sample. Meanwhile, heating and steaming reduced the total count by 1 and 2 logs with slight effect on reducing the total coliforms counts. Also, irradiated samples were free of coliforms. No considerable changes in the moisture and ash were observed in irradiated powders, but the moisture increased due to steaming, and decreased due to dried heating. Gamma irradiation at 10 kGy was more effective than heating and steaming treatments in their microbial decontamination effect on the licorice root powders.

  17. Effect of sodium ascorbate on degree of conversion and bond strength of RealSeal SE to sodium hypochlorite treated root dentin.

    PubMed

    Shrestha, Deepti; Wu, Wan-Cui; He, Qing-Yin; Wei, Xi; Ling, Jun-Qi

    2013-01-01

    The aim of this study was to investigate the effect of sodium ascorbate (Sa) on degree of conversion (DC) and bond strength (BS) of RealSeal SE to sodium hypochlorite (NaOCl) treated root dentin. Two hundreds simulated canals were prepared and irrigated with Distilled water(DW), 1.3% NaOCl (1.3% N), 5.2% NaOCl (5.2% N), MTAD, 17% EDTA (EDTA), 10% Sa, 1.3% NaOCl/MTAD (N-M), 1.3% NaOCl/Sa/MTAD(N-Sa-M), 5.2% NaOCl/EDTA(N-E), and 5.2% NaOCl/Sa/EDTA (N-Sa-E) respectively. They were subsequently bulk filled with RealSeal SE and analyzed with micro-Raman spectroscopy and universal testing machine for DC and BS respectively. One-way ANOVA and post hoc Tukey's test showed DC of 1.3% N, 5.2% N, N-M and N-E were significantly lower (p<0.01) than other six groups. BS of DW, Sa, N-M were significantly lower than 1.3% N, 5.2% N, MTAD, EDTA, N-Sa-M and N-E (p<0.01), and group N-Sa-E achieved the highest BS among all groups (p<0.01). NaOCl negatively affected DC and BS of RealSeal SE, which could be reversed with 10% Sa.

  18. Dentinal innervation of impacted human third molars.

    PubMed

    Lilja, J; Fagerberg-Mohlin, B

    1984-12-01

    Five totally impacted third molars were studied in the transmission electron microscope for the presence of nervous structures in the dentin before eruption. In contradiction to earlier studies available, nervous structures were found in the predentin and the dentin of the impacted third molars in different parts of the crown and also in the predentin of the root.

  19. Effects of different lasers on organic/inorganic ratio of radicular dentin.

    PubMed

    Lopes, F C; Roperto, R; Akkus, A; Akkus, O; Souza-Gabriel, A E; Sousa-Neto, M D

    2016-04-01

    The aim of this study was to evaluate the chemical stability of endodontic-treated root dentin after different laser irradiations through Raman spectroscopy. Fifty maxillary canines were selected and prepared with K3 system. Roots were randomly distributed into five groups (n = 10) according to the surface treatment: GI (water), GII (NaOCl + EDTA), GIII (NaOCl + EDTA + 980 nm Diode laser), GIV (NaOCl + EDTA+ 1064 nm Nd: YAG laser) and GV (NaOCl + EDTA+ 2780 nm Er,Cr: YSGG laser). Lasers were applied for 20 s. Samples were bisected, and the organic and inorganic content of dentin was analyzed by Raman spectroscopy. Data were submitted to ANOVA and Tukey tests (p < 0.05). None of the surface treatments alter the inorganic content (cts) (p = 0.183). Roots irradiated with Er,Cr: YSGG laser had a reduced collagen content (GV-290.7 ± 41.7) compared with the water-treated roots (GI-328.3 ± 63.5) and those treated with NaOCl + EDTA (GII-333.9 ± 55.8). Roots irradiated with Er,Cr: YSGG laser also showed a higher inorganic/organic ratio (GV-9.5 ± 1.1) than roots treated with water (GI-7.7 ± 1.5), NaOCl + EDTA (GII-8.0 ± 1.4) and diode laser (GIII-8.2 ± 1.6). Both organic and inorganic contents increased from cervical to apical thirds in all groups. None of the surface treatments were able to promote changes in the inorganic content of the root dentin; treatment with NaOCl + EDTA combined with Er,Cr: YSGG altered collagen.

  20. Holmium:YAG laser: effects on dentin demineralization

    NASA Astrophysics Data System (ADS)

    Holt, Raleigh A.; Nordquist, Robert E.

    1995-05-01

    The Holmium:YAG laser at 2.12 microns wavelength was used to compare the changes in resistance to demineralization of the dentinal root surfaces of human extracted teeth in vitro. Three protocols were used: Group #1, and application of nonfilled resin/NaF (4%) solution followed by exposure with the Holmium:YAG laser beam; Group #2, an application of an aqueous solution of NaF (4%) only; and Group #3, irradiation with the laser beam only. The teeth were exposed on the root surfaces with untreated control and experimental sites on opposite sides of the teeth. A 3 mm spot size covered an area of 3 X 5 mm with 0.450 (+/- .05) joules at a fluence of 2.66 - 3.3 J/cm2. All teeth were decalcified in a 10% Formic acid solution for a timed period. Samples were prepared for staining by sectioning the teeth at the dentoenamel junction and 3 mm apically to produce a cross-section of each tooth root surface. Each sample was placed in toluidine blue dye to observe the depth of dye penetration into the dentin of treated and control sites. Toluidine blue dye showed a consistent greater depth of dye penetration into the dentinal areas of the untreated control sites versus the resin/NaF-lased group. The topical fluoride only group did not appear different than the untreated control sites of the teeth. The lased only group showed areas of dye penetration similar to the untreated control sides with other areas of little or no dye penetration. The finding that HO:YAG laser energy/chemical agent produced increased resistance to demineralization of dentinal surfaces in vitro suggested potential clinical applications of this combined modality.

  1. Relined Fiberglass Post: Effect of Luting Length, Resin Cement, and Cyclic Loading on the Bond to Weakened Root Dentin.

    PubMed

    de Souza, N C; Marcondes, M L; da Silva, Dff; Borges, G A; Júnior, Lh Burnett; Spohr, A M

    This study evaluated the effects of luting length of the post, the resin cement, and cyclic loading on pull-out bond strength of fiberglass posts relined with composite resin in weakened roots. The canals of 80 bovine incisors were endodontically treated and weakened with diamond burs. The teeth were randomly divided into eight groups (n=10) according to the luting procedures of the relined fiberglass post (RFP): In groups 1, 2, 3, and 4, the RFPs were luted with RelyX ARC, and in groups 5, 6, 7, and 8 they were luted with RelyX U200. In groups 1, 3, 5, and 7, the RFPs were luted at a length of 5 mm, and in groups 2, 4, 6, and 8 they were luted at a length of 10 mm. Specimens from groups 3, 4, 7, and 8 were submitted to cyclic loading. Specimens were subjected to a pull-out bond strength test in a universal testing machine. The results (MPa) were analyzed by three-way analysis of variance and the Tukey post hoc test (α=0.05). Six human upper anterior teeth were used to analyze the bond interface by confocal laser scanning microscopy (CLSM). The pull-out bond strength of RFPs luted with RelyX U200 was statistically higher than that of RelyX ARC. Cyclic loading influenced the bond strength only for the luting length of 5 mm. CLSM analysis revealed the formation of resin cement tags for both materials. Luting length is an important factor in retaining RFPs in weakened roots when they are subjected to cyclic loading, and RelyX U200 resulted in greater bond strengths to the root canal in comparison with RelyX ARC.

  2. Influence of instrumentation techniques and irrigating solutions on bond strength of glass fiber posts to root dentin.

    PubMed

    Marques, Eduardo Fernandes; Bueno, Carlos Eduardo da Silveira; Veloso, Heloisa Helena Pinho; Almeida, Gustavo; Pinheiro, Sergio Luiz

    2014-01-01

    This study sought to evaluate how instrumentation techniques and irrigating solutions affected the bond strength of glass fiber posts. For this study, 80 human maxillary central incisors were selected. Endodontic access was obtained, root canal length was measured, and the coronal third was prepared using Gates-Glidden drills. The specimens were embedded in acrylic resin and randomly assigned to 8 groups (n = 10): manual instrumentation only (Group 1), rotary instrumentation only (Group 2), irrigation with 2.5% sodium hypochlorite (NaOCl) (Group 3), irrigation with 2% chlorhexidine (CHX) (Group 4), manual instrumentation and irrigation with 2.5% NaOCl (Group 5), manual instrumentation and irrigation with 2% CHX (Group 6), rotary instrumentation and irrigation with 2.5% NaOCl (Group 7), and rotary instrumentation and irrigation with 2% CHX (Group 8). Specimens in Groups 5-8 also received a 1 minute final rinse with ethylenediaminetetraacetic acid. Canals were filled and the specimens stored for 30 days in distilled water. The restoration material was removed down to the apical 4 mm of the root canal. The glass fiber posts were luted with resin cement and stored for 24 hours at 37°C. Specimens were subjected to a tensile strength test at a constant speed of 1.0 mm/minute and a load of 2,000 kgf. The results were analyzed by analysis of variance and Tukey's test. Irrigation with 2.5% NaOCl reduced the bond strength of fiber posts significantly (P < 0.01), while CHX showed no effect (P > 0.05). It was concluded that irrigation with 2.5% NaOCl has a negative effect on micromechanical retention of glass fiber posts, whether manual or rotary instrumentation is used.

  3. Effect of light-curing units on push-out fiber post bond strength in root canal dentin

    NASA Astrophysics Data System (ADS)

    Calixto, L. R.; Bandéca, M. C.; Silva, F. B.; Rastelli, A. N. S.; Porto-Neto, S. T.; Andrade, M. F.

    2009-08-01

    The purpose of this study was to evaluate the effectiveness of different light-curing units on the bond strength (push-out) of glass fiber posts in the different thirds of the root (cervical, middle and apical) with different adhesive luting resin systems (dual-cure total-etch; dual-cured and self-etch bonding system; and dual-cure self-adhesive cements), Disks of the samples ( n = 144) were used, with approximately 1 mm of thickness of 48 bovine roots restored with glass fiber posts, that were luted with resin cements photo-activated by halogen LCU (QTH, Optilux 501) and blue LED (Ultraled), with power densities of 600 and 550 mW/cm2, respectively. A universal testing machine (MTS 810 Material Test System) was used with a 1 mm diameter steel rod at cross-head speed of 0.5 mm/min until post extrusion, with load cell of 50 kg, for evaluation of the push-out strength in the different thirds of each sample. The push-out strength values in kgf were converted to MPa and analyzed through Analysis of Variance and Tukey’s test, at significance level of 5%. The results showed that there were no statistical differences between the QTH and LED LCUs. The self-adhesive resin cement had lower values of retention. The total-etch and self-adhesive system resin cements seem to be a possible alternative for glass fiber posts cementation into the radicular canal and the LED LCU can be applied as an alternative to halogen light on photo-activation of dual-cured resin cements.

  4. CYTOLOGICAL STUDIES OF ORGANOTYPIC CULTURES OF RAT DORSAL ROOT GANGLIA FOLLOWING X-IRRADIATION IN VITRO

    PubMed Central

    Masurovsky, Edmund B.; Bunge, Mary Bartlett; Bunge, Richard P.

    1967-01-01

    Long-term organotypic cultures of rat dorsal root ganglia were exposed to a single 40 kR dose of 184 kvp X-rays and studied in the living and fixed states by light or electron microscopy at 1–14 day intervals thereafter. Within the first 4 days following irradiation, over 30% of the neurons display chromatolytic reactions (eccentric nuclei, peripheral dispersal of Nissl substance, central granular zone) as well as abnormal nucleolar changes and dissociation of ribosomes from endoplasmic reticulum cisternae. Some satellite cells undergo retraction or acute degeneration, leaving only basement membrane to cover the neuron in these areas. 8 days after irradiation, neurons also exhibit (a) areas in which ribosomes are substantially reduced, (b) regions of cytoplasmic sequestration, (c) extensive vacuolization of granular endoplasmic reticulum and Golgi complex, and (d) diversely altered mitochondria (including the presence of ribosome-like particles or association with abnormal glycogen and lipid deposits). Nucleolar components become altered or reoriented and may form abnormal projections and ringlike configurations. Sizeable areas of the neuronal soma are now denuded of satellite cells; underlying these areas, nerve processes are found abnormally invaginated into the neuronal cytoplasm. By the 14th day following irradiation, most neurons display marked degenerative changes including extensive regions of ribosome depletion, sequestration, vacuolization, autolysis, and, in some areas, swirls of filaments, myelin figures, and heterogeneous dense bodies. These observations demonstrate that X-irradiation produces profound cytopathological changes in nervous tissue isolated from the host and that many of these changes resemble the effects of radiation on nervous tissue in vivo. PMID:10976234

  5. Root Surface Temperature Changes During Root Canal Laser Irradiation with Dual Wavelength Laser (940 and 2780 nm): A Preliminary Study.

    PubMed

    Haidary, Darya; Franzen, René; Gutknecht, Norbert

    2016-08-01

    This study aimed to evaluate the temperature changes on the root surface during root canal irradiation using 2780 nm erbium, chromium: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) and 940 nm diode lasers in an alternating sequence. Eighteen single-rooted human teeth were randomly divided into three groups (n = 6). Teeth were embedded in a resin block, and six thermocouples were introduced at different positions on the tooth surfaces, while immersed in a 37°C thermal bath during laser irradiation. The laser radial firing tip (RFT)2 was operated in helicoidal movements and withdrawn from the root canal in a coronal direction at a speed of 2 mm/sec. Group A was irradiated with the Er,Cr:YSGG laser (1.25 W, 25 mJ, 50 Hz, 50 μs pulse duration, 50% water, and 30% air spray); Group B was irradiated with the Er,Cr:YSGG laser (same settings) and a 940 nm diode (2 W, with 20% duty cycle), and Group C was irradiated with the Er,Cr:YSGG laser (same settings) and a 940 nm diode (2 W, 50% duty cycle). The maximum temperature recorded was in the apical thirds of Groups A-C, resulting in increments of 8.35°C, 7.33°C, and 3.82°C, respectively. All measured temperatures were considerably below the critical value of 10°C. The alternate use of Er,Cr:YSGG and 940 nm diode lasers can be considered biologically safe to be used in endodontics.

  6. Soluble carbohydrate allocation to roots, photosynthetic rate of leaves, and nitrate assimilation as affected by nitrogen stress and irradiance

    NASA Technical Reports Server (NTRS)

    Henry, L. T.; Raper, C. D. Jr

    1991-01-01

    Upon resupply of exogenous nitrogen to nitrogen-stressed plants, uptake rate of nitrogen is enhanced relative to nonstressed plants. Absorption of nitrogen presumably is dependent on availability of carbohydrates in the roots. A buildup in soluble carbohydrates thus should occur in roots of nitrogen-stressed plants, and upon resupply of exogenous nitrogen the increased uptake rate should be accompanied by a rapid decline in carbohydrates to prestress levels. To evaluate this relationship, three sets of tobacco plants growing in a complete hydroponic solution containing 1.0 mM NO3- were either continued in the complete solution for 21 d, transferred to a minus-nitrogen solution for 21 d, or transferred to a minus-nitrogen solution for 8-9 d and then returned to the 1.0 mM NO3- solution. These nitrogen treatments were imposed upon plants growing at photosynthetic photon flux densities of 700 and 350 micromoles m-2 s-1. Soluble carbohydrate levels in roots increased during onset of nitrogen stress to levels that were fourfold greater than in roots of non-stressed plants. Following resupply of external nitrogen, a rapid resumption of nitrogen uptake was accompanied by a decline in soluble carbohydrates in roots to levels characteristic of nonstressed plants. This pattern of soluble carbohydrate levels in roots during onset of and recovery from nitrogen stress occurred at both irradiance levels. The response of net photosynthetic rate to nitrogen stress could be expressed as a nonlinear function of concentration of reduced nitrogen in leaves. The net photosynthetic rate at a given concentration of reduced nitrogen, however, averaged 10% less at the lower than at the higher irradiance. The decline in net photosynthetic rate per unit of reduced nitrogen in leaves at the lower irradiance was accompanied by an increase in the nitrate fraction of total nitrogen in leaves from 20% at the higher irradiance to 38% at the lower irradiance.

  7. Soluble carbohydrate allocation to roots, photosynthetic rate of leaves, and nitrate assimilation as affected by nitrogen stress and irradiance

    NASA Technical Reports Server (NTRS)

    Henry, L. T.; Raper, C. D. Jr

    1991-01-01

    Upon resupply of exogenous nitrogen to nitrogen-stressed plants, uptake rate of nitrogen is enhanced relative to nonstressed plants. Absorption of nitrogen presumably is dependent on availability of carbohydrates in the roots. A buildup in soluble carbohydrates thus should occur in roots of nitrogen-stressed plants, and upon resupply of exogenous nitrogen the increased uptake rate should be accompanied by a rapid decline in carbohydrates to prestress levels. To evaluate this relationship, three sets of tobacco plants growing in a complete hydroponic solution containing 1.0 mM NO3- were either continued in the complete solution for 21 d, transferred to a minus-nitrogen solution for 21 d, or transferred to a minus-nitrogen solution for 8-9 d and then returned to the 1.0 mM NO3- solution. These nitrogen treatments were imposed upon plants growing at photosynthetic photon flux densities of 700 and 350 micromoles m-2 s-1. Soluble carbohydrate levels in roots increased during onset of nitrogen stress to levels that were fourfold greater than in roots of non-stressed plants. Following resupply of external nitrogen, a rapid resumption of nitrogen uptake was accompanied by a decline in soluble carbohydrates in roots to levels characteristic of nonstressed plants. This pattern of soluble carbohydrate levels in roots during onset of and recovery from nitrogen stress occurred at both irradiance levels. The response of net photosynthetic rate to nitrogen stress could be expressed as a nonlinear function of concentration of reduced nitrogen in leaves. The net photosynthetic rate at a given concentration of reduced nitrogen, however, averaged 10% less at the lower than at the higher irradiance. The decline in net photosynthetic rate per unit of reduced nitrogen in leaves at the lower irradiance was accompanied by an increase in the nitrate fraction of total nitrogen in leaves from 20% at the higher irradiance to 38% at the lower irradiance.

  8. Push-out bond strength of fiber posts to root canal dentin using a one-step self-etching adhesive: the effect of solvent removal and light-curing methods.

    PubMed

    Aziz, Tarek M; Anwar, Mohammed N; El-Askary, Farid S

    2014-02-01

    To evaluate the effect of solvent removal and light-curing methods on the push-out bond strength of fiber posts to root canal dentin using a one-step self-etching adhesive. Eighty single-rooted, single-canal human mandibular premolars were used in this study. After removal of the crown, the pulp was extirpated and the post space was prepared. The teeth were divided into two main groups according to the solvent removal method, either using the paper point or the air-drying method. Each of the above main groups was further subdivided into 4 subgroups according to the light-curing method: group 1: both adhesive and resin cement were cured from the top of the post in the same step (cocuring) for 40 s; group 2: the adhesive was light cured for 20 s and the resin cement for 40 s; group 3: the adhesive was light cured for 40 s as was the resin cement; group 4: an intracanal tip was used to cure the adhesive inside the post space for 20 s. In groups 1 to 4, the solvent was evaporated using oil-free compressed air for 5 s from the root surface and excess adhesive was removed from inside the canal using a paper point. In groups 5 to 8, the adhesive and cement were applied and light cured as in groups 1 to 4, except the solvent was evaporated (air dried) from inside the post space using an intra-canal disposable plastic tip attached to the tip of a 3-way syringe. After 24 hours, three 2-mm-thick root slices were obtained from each root. Each slice was subjected to the push-out bond strength test at a crosshead speed of 0.5 mm/min. Factorial analysis (two-way ANOVA) was run to test the effect of solvent evaporation method, light-curing method, and their interactions on bond strength. One-way ANOVA followed by Duncan's Multiple Range Test were used to test the effect of lightcuring method on bond strength within each solvent evaporation method. Student's t-test was performed to compare the effect of solvent evaporation method on bond strength within each light-curing method

  9. Comparison of tensile bond strengths of four one-bottle self-etching adhesive systems with Er:YAG laser-irradiated dentin.

    PubMed

    Jiang, Qianzhou; Chen, Minle; Ding, Jiangfeng

    2013-12-01

    This study aimed to investigate the interaction of current one-bottle self-etching adhesives and Er:YAG laser with dentin using a tensile bond strength (TBS) test and scanning electron microscopy (SEM) in vitro. Two hundred and thirteen dentin discs were randomly distributed to the Control Group using bur cutting and to the Laser Group using an Er:YAG laser (200 mJ, VSP, 20 Hz). The following adhesives were investigated: one two-step total-etch adhesive [Prime & Bond NT (Dentsply)] and four one-step self-etch adhesives [G-Bond plus (GC), XENO V (Dentsply), iBond Self Etch (Heraeus) and Adper Easy One (3 M ESPE)]. Samples were restored with composite resin, and after 24-hour storage in distilled water, subjected to the TBS test. For morphological analysis, 12 dentin specimens were prepared for SEM. No significant differences were found between the control group and laser group (p = 0.899); dentin subjected to Prime & Bond NT, XENOV and Adper Easy One produced higher TBS. In conclusion, this study indicates that Er:YAG laser-prepared dentin can perform as well as bur on TBS, and some of the one-step one-bottle adhesives are comparable to the total-etch adhesives in TBS on dentin.

  10. Effects of distance from the pulp and thickness on the hydraulic conductance of human radicular dentin.

    PubMed

    Fogel, H M; Marshall, F J; Pashley, D H

    1988-11-01

    The purposes of this study were: (1) to measure the effect of distance from the pulp on the hydraulic conductance of human radicular dentin; (2) to determine the influence of dentin thickness on the rates of fluid flow; and (3) to attempt to correlate dentinal tubule densities and diameters with root dentin hydraulic conductance. Dentin slabs prepared from extracted, unerupted, human third molar teeth were placed in a split-chamber device to permit quantitation of fluid filtration rate (hydraulic conductance). In the SEM portion of the study, dentinal tubule numbers and diameters were recorded. The results indicated that radicular dentin hydraulic conductance decreased with distance from the pulp and with increasing dentin thickness. Tubule density and diameter correlated well with the measured hydraulic conductances. The relatively low hydraulic conductance of outer root dentin makes it a significant barrier to fluid movement across root structure.

  11. Role of Dentin Compositional Changes and Structural Loss on Fracture Predilection in Endodontically Treated Teeth

    NASA Astrophysics Data System (ADS)

    Ossareh, Arezou

    The aim of this study was to examine the role of chemical compositional changes and iatrogenic dentin structural loss on the mechanical response of teeth to force and resistance to fracture. The experiments were divided into three phases. In phase 1, experimental studies were performed to evaluate the effect of chemicals used during treatment on ultrastructure, composition and resistance to fracture of dentin. In phase 2, experimental studies were used to evaluate the influence of dentin removal and remaining dentin volume on the resistance to fracture and microcrack formation in root dentin. In phase 3 finite element analysis was carried out to examine the influence of dentin loss on the stress distribution in root dentin. The combination of experimental and numerical analysis highlighted the role of remaining dentin volume and moment of inertia on root dentin biomechanics.

  12. Scanning ablation of root caries with acoustic feedback control

    NASA Astrophysics Data System (ADS)

    Fan, Kenneth; Fried, Daniel

    2007-02-01

    It has been previously demonstrated that short λ=355-nm laser pulses can be used for the selective removal of caries lesions and composite restorative materials from occlusal surfaces with minimal damage to the peripheral sound tooth structure. One advantage of laser-systems is they can be integrated with acoustic and optical feedback systems for the automated discrimination of dental caries and restorative materials. The objective of this study was to test the hypothesis that root caries could be selectively removed from tooth surfaces using a computer controlled laserscanning system coupled with an acoustic feedback system. Dental root caries surfaces on extracted teeth were scanned with λ=355-nm laser pulses at irradiation intensities ranging from 0.6 to 0.8 J/cm2. Acoustic feedback signals were acquired and used to control the laser output and scanning stages were used to position the laser over carious dentin until all the caries were removed to a fixed depth. Polarization optical coherence tomography (PSOCT) was used to acquire images of the root caries lesions before and after removal by the laser in order to assess if ablation was selective. The amplitude of the acoustic waves generated during the ablation of carious dentin was higher than for sound dentin allowing the acoustic feedback system to discriminate between sound and carious dentin. PS-OCT showed that caries were removed to a depth of up to 1.5-mm with minimal peripheral damage to peripheral sound dentin. The acoustic feedback was successfully used to distinguish between root caries and sound dentin, enabling the selective removal of caries from dentin surfaces using a λ=355-nm, Nd:YAG Q-switched laser system.

  13. Optical Spectroscopy Study of Transparent Non-Carious Human Dentin and Dentin-Enamel Junction

    SciTech Connect

    Marshall, G.W.; Marshall, S.J.; Gallagher, R.R.; Demos, S.

    1999-12-14

    Improving our knowledge of the morphology, composition and properties of the dentin, enamel, and the dentin-enamel junction (DEJ) is vital for the development of improved restorative materials and clinical placement techniques. Most studies of dental tissues have used light microscopy for characterization. In our investigation, the spectroscopic properties of normal and non-carious transparent human root dentin, and the dentin-enamel junction were investigated using emission imaging microscopy, and micro-spectroscopy. Experimental results reveal new information on the structural and biochemical characteristics of these dental tissues.

  14. Functional remineralization of carious dentin

    NASA Astrophysics Data System (ADS)

    Pugach, Megan Kardon

    A primary goal of dental tissue engineering is the biological reconstruction of tooth substrate destroyed by caries or other diseases affecting tooth mineralization. Traditionally, dentists treat caries by using invasive techniques to remove the diseased dental tissue and restore the lesion, ideally preventing further progression of decay. Success in strategies associated with remineralization of enamel and root caries have contributed to the less invasive prospect of remineralization of dentinal carious lesions. The central hypothesis of this dissertation is that carious dentin lesions can be remineralized if the lesions contain residual mineral. Caries Detector (CD) stained zones (pink, light pink, transparent and normal) of arrested carious dentin lesions were characterized according to microstructure by atomic force microscopy (AFM) imaging, mineral content by digital transverse microradiography, and nanomechanical properties by AFM-based nanoindentation. CD-stained and unstained zones had significantly different microstructure, mineral content and nanomechanical properties. Furthermore, the most demineralized carious zone contained residual mineral. To obtain reproducible, standardized dentin caries lesions, we characterized the lesions from an artificial carious dentin lesion model using a 0.05M acetate demineralization buffer. The artificial caries-like lesions produced by the buffer had similar mineral content and nanomechanical properties in the stained and unstained zones as natural dentin lesions. Both natural and artificial lesions had significant correlations between mineral content and nanomechanical properties. Mineral crystallite size and shape was examined by small angle x-ray scattering. Both natural and artificial carious dentin had different mineral sizes than normal dentin. Collagen in natural and artificial carious dentin lesions was examined by trichrome stain, AFM high-resolution imaging, and UV resonance Raman spectroscopy, to determine if

  15. Transmission electron microscopic characterization of hypersensitive human radicular dentin

    SciTech Connect

    Yoshiyama, M.; Noiri, Y.; Ozaki, K.; Uchida, A.; Ishikawa, Y.; Ishida, H. )

    1990-06-01

    Transmission electron microscopy (TEM) and x-ray microanalysis (XMA) were used for the study of the ultrastructure of the lumens of dentinal tubules in superficial layers of dentin specimens obtained by use of a new biopsy technique from both hypersensitive and naturally desensitized areas of exposed root surfaces, in vivo. The TEM images showed clearly that the lumens of most of the tubules were occluded with mineral crystals in naturally desensitized areas, but such lumens were empty and surrounded with peritubular and intertubular dentin in hypersensitive areas. Moreover, electron-dense structures that lined peritubular dentin were observed in the empty lumens of dentinal tubules.

  16. Lack of correlation between tubular dentine cement penetration, adhesiveness and leakage in roots filled with gutta percha and an endodontic cement based on epoxy amine resin

    PubMed Central

    MACHADO, Ricardo; da SILVA NETO, Ulisses Xavier; CARNEIRO, Everdan; FARINIUK, Luiz Fernando; WESTPHALEN, Vânia Portela Ditzel; CUNHA, Rodrigo Sanches

    2014-01-01

    Objective To analyze possible correlations among tubular dentine cement penetration, adhesiveness and apical leakage in fillings performed with gutta percha and an endodontic cement based on epoxy amine resin. Material and Methods Sixty similar, extracted human mandibular central incisors were irrigated, instrumented and filled following the same protocol. First, apical leakage was quantified by fluid filtration tests. Then, these same specimens were sectioned for analysis of tubular dentine cement penetration and the middle thirds were submitted to push-out tests to analyze the adhesiveness of the fillings. Results In brief, the means and standard deviations with a confidence interval of 95% were as follows: tubular dentine cement penetration (8.875±4.540), adhesiveness (4.441±2.683) and apical leakage (0.318±0.215). The data were confronted using the Pearson's test (P>0.05), and it was possible to prove that there was no correlation between (1) tubular dentine cement penetration and apical leakage (r2: 0.08276), (2) tubular dentine cement penetration and adhesiveness (r2: -0.2412) and (3) adhesiveness and apical leakage (r2: 0.1340). Conclusion After analysis of these data, it could be observed that there exists no correlation among the variables analyzed in this study. PMID:24626245

  17. Intrapulpal temperature changes during root surface irradiation with dual-wavelength laser (2780 and 940 nm): in vitro study

    NASA Astrophysics Data System (ADS)

    Franzen, Rene; Rashidisangsary, Borna; Ozturan, Seda; Vanweersch, Leon; Gutknecht, Norbert

    2015-01-01

    The present study evaluated the intrapulpal thermal changes that occurred during the treatment of the root surfaces with a laser system emitting Er,Cr:YSGG 2780- and 940-nm diode laser irradiation in an alternating sequence. Thirty single-rooted human teeth were collected. The teeth were divided into three groups (n=10 each) and irradiated with Er,Cr:YSGG alone or combined with a 940-nm diode laser. To investigate the intrapulpal temperature changes, specimens were embedded in a resin block with a set of thermocouples introduced at different positions within the root canals. The first group was irradiated with only Er,Cr:YSGG (25 mJ, 50 Hz, 50 μs pulse duration, water and air spray); the second group was irradiated with Er,Cr:YSGG (same setting) and a 940-nm diode (2 W, chopped mode with 20% duty cycle); the third group was irradiated with Er,Cr:YSGG (same setting) and a diode (2 W, chopped mode with 50% duty cycle). During all irradiations, thermal changes were recorded in real time with thermocouples. While group 3 showed thermal rises on average of 1.68±0.98°C in the pulp chamber, groups 1 and 2 showed average temperature rises of <0.5°C. The combined laser emission of 2780 and 940 nm is a promising way for root surface debridement without inducing intrapulpal thermal damage when using an appropriate water/air spray. All measured temperatures were considerably below the critical value of 5.6°C.

  18. Effect of solvent evaporation strategies on regional bond strength of one-step self-etch adhesives to root canal dentine.

    PubMed

    Thitthaweerat, S; Nakajima, M; Foxton, R M; Tagami, J

    2013-11-01

    To evaluate the efficacy of different solvent evaporation strategies on bonding of one-step self-etch adhesives to root canal dentine. Two dual-cure resin core systems (Clearfil DC Bond/Clearfil DC Core Automix and Clearfil Tri-S Bond Plus/Clearfil DC Core Plus; Kuraray Noritake Dental, Tokyo, Japan) were equally applied in 24 post spaces from extracted human mandibular premolars. After the adhesive application, specimens were randomly assigned into four water/solvent evaporation strategies as follows (I) insertion of absorbent paper point for 10 s: P, (II) 10 s air-blowing: A, (III) as (II) followed by insertion of absorbent paper point: AP, (IV) as (III) followed by 10 s additional air-blowing: APA. Then, the adhesives were light cured, and resin core materials were placed into the post space, followed by light curing for 60 s. After water storage for 24 h, 0.6 × 0.6 mm-thick beams were prepared to measure the regional μTBS. The mode of failure was also observed. The μTBS values were statistically analysed using three-way anova and Duncan HSD test (α = 0.05). In the coronal region, there were no significant differences in μTBS between each evaporation strategy (P > 0.05), except P group. However, in the apical region, APA and AP groups significantly increased in μTBS compared with A and P groups (P < 0.05). Only in the APA group of Clearfil Tri-S Bond Plus/Clearfil DC Core Plus, was there no significant difference in μTBS between the coronal and apical regions (P > 0.05). The use of paper points with additional air-blowing for removing excessive adhesive and evaporating residual water/solvent would be effective in producing higher bond strength for the tested one-step self-etch adhesives and fewer blister formations in deeper regions of the post space. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  19. CYTOLOGICAL STUDIES OF ORGANOTYPIC CULTURES OF RAT DORSAL ROOT GANGLIA FOLLOWING X-IRRADIATION IN VITRO

    PubMed Central

    Masurovsky, Edmund B.; Bunge, Mary Bartlett; Bunge, Richard P.

    1967-01-01

    Under suitable conditions rat dorsal root ganglia differentiate and myelinate in culture, providing an organotypic model of the ganglion (8). Mature cultures of this type were irradiated with a 40 kR dose of 184 kvp X-rays and, after daily observation in the living state, were fixed for light and electron microscopy. Within 24 hr after irradiation, numerous Schwann cells investing unmyelinated axons acutely degenerate. The axons thus denuded display little change. Conversely, few ultrastructural changes develop in Schwann cells investing myelinated axons until after the 4th day. During the 4–14 day period, these Schwann cells and their related myelin sheaths undergo progressive deterioration. Associated axons decrease in diameter but are usually maintained. Myelin deterioration begins as a nodal lengthening and then progresses along two different routes. In intact Schwann cells, fragmentation of myelin begins in a pattern reminiscent of Wallerian degeneration, but its slow breakdown thereafter suggests metabolic disturbances in these Schwann cells. The second pattern of myelin deterioration, occurring after complete degeneration of the related Schwann cell, involves unusual configurational changes in the myelin lamellae. Atypical repeating periods are formed by systematic splitting of lamellae at each major dense line with further splitting at the intraperiod line (Type I) or by splitting in the region of every other intraperiod line (Type II); some sheaths display a compact, wavy, inner zone and an abnormally widened lamellar spacing peripherally (Type III). Extensive blebbing of myelin remnants characterizes the final stages of this extracellular myelin degradation. These observations provide the first description of ultrastructural changes produced by ionizing radiation in nerve fascicles in vitro. PMID:10976235

  20. Microbial contamination of the environment after the irradiation of Er:YAG laser in infected root canals

    NASA Astrophysics Data System (ADS)

    Brugnera, Aldo, Jr.; Zanin, Fatima A. A.; Sampaio Moura, Marcelo; Heredia Seixas, Fabio; Rodrigues de Araujo Estrela, Cyntia; Estrela, Carlos; Djalma Pecora, Jesus

    2003-06-01

    The purpose of this study was to analyze the environment microbial contamination produced by Er:YAG laser irradiation in infected root canals. A total of 20 human anterior teeth were prepared, sterilized and, then, inoculated with a mixture of the following microorganisms: S. Aureus, E. Faecalis, P. Aeruginosa, B. Subtilis and C. Albicans. After the contamination period (28 days), the teeth were irrigated with sterile distilled water or 1% sodium hypochlorite and, then, irradiated with an Er:YAG laser with two different laser parameters: 52 mJ or 110 mJ output at the fiber tip. Eighteen Petri dishes with 20 ml of BHI Agar were used in the study. For each group, 3 plates with BHIA were used for the analysis of the microbial contamination of the environment during the activation of the laser in infected root canals. The plates were positioned in differing distances away from the irradiated tooth (plate 1 - distance of 15 cm, plate 2 - distance of 50 cm and plate 3 - distance of 3 meters). After the analysis of the results, it was observed that the larger microbial contamination occurred in Group 1 (teeth irrigated with sterile distilled water and irradiated with Er:YAG laser with 52 mJ output at the fiber tip), plate 1 (positioned 15 cm away from the irradiated tooth), with values greater than 30 Colony-Forming Units (CFU).

  1. Bond strength of etch-and-rinse and self-etch adhesive systems to enamel and dentin irradiated with a novel CO2 9.3 μm short-pulsed laser for dental restorative procedures.

    PubMed

    Rechmann, Peter; Bartolome, N; Kinsel, R; Vaderhobli, R; Rechmann, B M T

    2017-08-15

    The objective of this study was to evaluate the influence of CO2 9.3 μm short-pulsed laser irradiation on the shear bond strength of composite resin to enamel and dentin. Two hundred enamel and 210 dentin samples were irradiated with a 9.3 µm carbon dioxide laser (Solea, Convergent Dental, Inc., Natick, MA) with energies which either enhanced caries resistance or were effective for ablation. OptiBond Solo Plus [OptiBondTE] (Kerr Corporation, Orange, CA) and Peak Universal Bond light-cured adhesive [PeakTE] (Ultradent Products, South Jordan, UT) were used. In addition, Scotchbond Universal [ScotchbondSE] (3M ESPE, St. Paul, MN) and Peak SE self-etching primer with Peak Universal Bond light-cured adhesive [PeakSE] (Ultradent Products) were tested. Clearfil APX (Kuraray, New York, NY) was bonded to the samples. After 24 h, a single plane shear bond test was performed. Using the caries preventive setting on enamel resulted in increased shear bond strength for all bonding agents except for self-etch PeakSE. The highest overall bond strength was seen with PeakTE (41.29 ± 6.04 MPa). Etch-and-rinse systems achieved higher bond strength values to ablated enamel than the self-etch systems did. PeakTE showed the highest shear bond strength with 35.22 ± 4.40 MPa. OptiBondTE reached 93.8% of its control value. The self-etch system PeakSE presented significantly lower bond strength. The shear bond strength to dentin ranged between 19.15 ± 3.49 MPa for OptiBondTE and 43.94 ± 6.47 MPa for PeakSE. Etch-and-rinse systems had consistently higher bond strength to CO2 9.3 µm laser-ablated enamel. Using the maximum recommended energy for dentin ablation, the self-etch system PeakSE reached the highest bond strength (43.9 ± 6.5 MPa).

  2. Hydromechanics in dentine: role of dentinal tubules and hydrostatic pressure on mechanical stress-strain distribution.

    PubMed

    Kishen, A; Vedantam, S

    2007-10-01

    This investigation is to understand the role of free water in the dentinal tubules on the mechanical integrity of bulk dentine. Three different experiments were conducted in this study. In experiment 1, three-dimensional models of dentine with gradient elastic modulus, homogenous elastic modulus, and with and without hydrostatic pressure were simulated using the finite element method. Static compressive loads of 15, 50 and 100 N were applied and the distribution of the principal stresses, von Mises stresses, and strains in loading direction were determined. In experiment 2, experimental compression testing of fully hydrated and partially dehydrated dentine (21 degrees C for 72 h) was conducted using a Universal testing machine. In experiment 3, Fourier transform infrared spectroscopic analysis of hydrated and partially dehydrated dentine was carried out. The finite element analysis revealed that the dentine model with simulated hydrostatic pressure displayed residual tensile stresses and strains in the inner region adjacent to the root canal. When external compressive loads were applied to the model, the residual stresses and strains counteracted the applied loads. Similarly the hydrated specimens subjected to experimental compression loads showed greater toughness when compared to the partially dehydrated specimens. The stress at fracture was significantly higher in partially dehydrated specimens (p=0.014), while the strain at fracture was significantly higher in hydrated dentine specimens (p=0.037). These experiments highlighted the distinct role of free water in the dentinal tubules and hydrostatic pressure on the stress-strain distribution within the bulk dentine.

  3. Dentin conditioning codetermines cell fate in regenerative endodontics.

    PubMed

    Galler, Kerstin M; D'Souza, Rena N; Federlin, Marianne; Cavender, Adriana C; Hartgerink, Jeffrey D; Hecker, Stephanie; Schmalz, Gottfried

    2011-11-01

    Recent successes in dental pulp engineering indicate that regenerative treatment strategies in endodontics are feasible. Clinically, revascularization procedures render completion of root formation in immature teeth. The generation of a pulp-like tissue after seeding of dental pulp stem cells into dentin discs or cylinders and transplantation in vivo is possible. In this experimental setup, which mimics the situation in the root canal, the pretreatment of dentin might influence cellular behavior at the cell-dentin interface. Thus, the objective of this study was to investigate whether dentin conditioning can determine cell fate. Dental pulp stem cells (DPSCs) were seeded into a growth factor-laden peptide hydrogel, transferred into dentin cylinders, and transplanted subcutaneously into immunocompromised mice. Before cell seeding, dentin cylinders were either pretreated with sodium hypochloride (NaOCl) or conditioned with EDTA. The constructs were explanted after 6 weeks and subjected to histological and immunohistochemical analysis. In dentin treated with NaOCl, resorption lacunae were found at the cell-dentin interface created by multinucleated cells with clastic activity. After conditioning with EDTA, DPSCs adjacent to the dentin formed an intimate association with the surface, differentiated into odontoblasts-like cells that expressed dentin sialoprotein, and extended cellular processes into the dentinal tubules. A vascularized soft connective tissue similar to dental pulp was observed inside the dentin cylinder. Dentin conditioning considerably influences DPSC fate when seeded in close proximity to dentin. This information might be critical for optimized strategic planning for future regenerative endodontic treatment. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  4. Irradiation effects on color and functional properties of persimmon ( Diospyros kaki L. folium) leaf extract and licorice ( Glycyrrhiza Uralensis Fischer) root extract during storage

    NASA Astrophysics Data System (ADS)

    Jo, Cheorun; Son, Jun Ho; Shin, Myung Gon; Byun, Myung Woo

    2003-06-01

    Irradiation effects on color and functional properties of persimmon ( Diospyros kaki L. folium) leaf extract and licorice ( Glycyrrhiza Uralensis Fischer) root extract were studied. Persimmon leaf and licorice root extracts were irradiated using 60Co gamma irradiator at 0 and 20 kGy absorbed dose and stored at 4°C or -20°C for 2 weeks. Tyrosinase inhibition effect (TIE) of both extracts was not different by 20 kGy-irradiation but reduced during storage. Electron donating ability (EDA) of the persimmon leaf extract was generally consistent, but that of licorice root extract was reduced by irradiation except for 1 week of storage. Both TIE and EDA of persimmon leaf extract were higher than that of licorice root. Hunter color L*-, a*-, and b*-values were changed, resulting in a desirable brighter color by irradiation. During storage, the bright yellow color of irradiated sample changed to brown gradually, and especially the changes in the refrigeration condition (4°C) was faster than frozen (-20°C). Results indicate that irradiation can be a useful method to produce value-added natural ingredients with functions such as persimmon leaf or licorice root for food or cosmetic industry in addition to elimination of microbial load.

  5. Histological and SEM analysis of root cementum following irradiation with Er:YAG and CO2 lasers.

    PubMed

    Almehdi, Aslam; Aoki, Akira; Ichinose, Shizuko; Taniguchi, Yoichi; Sasaki, Katia M; Ejiri, Kenichiro; Sawabe, Masanori; Chui, Chanthoeun; Katagiri, Sayaka; Izumi, Yuichi

    2013-01-01

    Recently, the Er:YAG and CO(2) lasers have been applied in periodontal therapy. However, the characteristics of laser-irradiated root cementum have not been fully analyzed. The aim of this study was to precisely analyze the alterations of root cementum treated with the Er:YAG and the CO(2) lasers, using non-decalcified thin histological sections. Eleven cementum plates were prepared from extracted human teeth. Pulsed Er:YAG laser contact irradiation was performed in a line at 40 mJ/pulse (14.2 J/cm(2)/pulse) and 25 Hz (1.0 W) under water spray. Continuous CO(2) laser irradiation was performed in non-contact mode at 1.0 W, and ultrasonic instrumentation was performed as a control. The treated samples were subjected to stereomicroscopy, scanning electron microscopy (SEM), light microscopy and SEM energy dispersive X-ray spectroscopy (SEM-EDS). The Er:YAG laser-treated cementum showed minimal alteration with a whitish, slightly ablated surface, whereas CO(2) laser treatment resulted in distinct carbonization. SEM analysis revealed characteristic micro-irregularities of the Er:YAG-lased surface and the melted, resolidified appearance surrounded by major and microcracks of the CO(2)-lased surface. Histological analysis revealed minimal thermal alteration and structural degradation of the Er:YAG laser-irradiated cementum with an affected layer of approximately 20-μm thickness, which partially consisted of two distinct affected layers. The CO(2)-lased cementum revealed multiple affected layers showing different structures/staining with approximately 140 μm thickness. Er:YAG laser irradiation used with water cooling resulted in minimal cementum ablation and thermal changes with a characteristic microstructure of the superficial layer. In contrast, CO(2) laser irradiation produced severely affected distinct multiple layers accompanied by melting and carbonization.

  6. [Effect of irradiation on tooth hard tissue and its resistance to acid].

    PubMed

    Zhang, Xue; Li, Yu-Jing; Wang, Song-Ling; Xie, Jian-Yun

    2004-11-01

    To study the effect of irradiation on the susceptibility of radiation caries. The structures of 56 teeth enamel and dentin of 63 roots were observed using SEM and the collagen fibre and the resistance to the acid were also investigated after irradiation of 30 Gy, 50 Gy and 70 Gy. The enamel structure changes were found after irradiation with different doses. The significant difference was found in the enamel changes between high or middle dose group and low dose group or control. The dentin morphology changed, some collagen fibre vanished and resistance to acid was reduced after irradiation with 50 Gy and 70 Gy. The radiation reduced the resistance of teeth to the acid and increased the caries susceptibility.

  7. Comparative Morphologic Evaluation and Occluding Effectiveness of Nd: YAG, CO2 and Diode Lasers on Exposed Human Dentinal Tubules: An Invitro SEM Study

    PubMed Central

    Grover, Harpreet Singh; Choudhary, Pankaj

    2016-01-01

    Introduction Dentinal hypersensitivity is one of the most common problem, encountered in dental practice but has least predictable treatment outcome. The advent of lasers in dentistry has provided an additional therapeutic option for treating dentinal hypersensitivity. Although various lasers have been tried over a period of time to treat dentinal hypersensitivity, but still the doubt persist as to which laser leads to maximum dentinal tubular occlusion and is most suitable with minimal hazardous effects. Aim To compare the effects of Nd: YAG, CO2 and 810-nm diode lasers on width of exposed dentinal tubule orifices and to evaluate the morphologic changes on dentinal surface of human tooth after laser irradiation by scanning electron microscope (SEM). Materials and Methods Forty root specimens were obtained from ten freshly extracted human premolars, which were randomly divided into four groups of ten each. Group I: control group treated with only saline, Group II: Nd:YAG laser, Group III: CO2 laser and Group IV: 810-nm diode laser. The specimens were examined using SEM. After calculating mean tubular diameter for each group, the values were compared statistically using parametric one-way ANOVA test and Turkey’s post hoc multiple comparison test. Results All the three lased groups showed a highly statistical significant result with p-value of <0.001 as compared to non-lased group. On intergroup comparison within the lased groups, all the three groups showed statistically significant difference in the reduction of dentinal tubular diameter (p-value < 0.001). Conclusion Nd: YAG laser was found to be most effective, followed by the CO2 laser and 810-nm diode laser was found to be least effective. The morphologic changes like craters, cracks and charring effect of the dentine were seen maximum by the use of CO2 laser. PMID:27630957

  8. Effects of Er:YAG and Nd:YAG laser irradiation on the permeability of instrumented root canal walls

    NASA Astrophysics Data System (ADS)

    Brugnera, Aldo, Jr.; Zanin, Fatima A. A.; Barbin, Eduardo L.; Emboava Spano, Julio C.; Santana da Silva, Reginaldo; Pecora, Jesus D.

    2002-06-01

    The aim of this study was to evaluate the effect of Er:YAG and Nd:YAG laser on radicular dentine permeability when using distilled and deionized water and 1% sodium hypochlorite as irrigating solutions. Thirty human maxillary canines obtained from laboratory stock and conserved in 0.1% thymol until use were divided randomly into six groups of five teeth each. The root canals were instrumented with K files and the step-back technique. The surgical diameter was achieved 4 files above the original anatomical diameter. Group I, the teeth were irrigated with distilled and deionized water; Group II, the teeth were irrigated with 1% sodium hypochlorite, Group II the teeth were irrigated with distilled and deionized water and then Er:YAG laser was applied with 140mJ, 15Hz, 300 pulses and 42J; group 4 the teeth were irrigated with 1% sodium hypochlorite and Er:YAG laser was applied in the same parameters as Group III, Group V, the teeth received irrigation with distilled and deionized water and Nd:YAG laser application with 150mJ, 15Hz, 2,25W and Group VI the teeth were irrigated with 1% sodium hypochlorite and Nd:YAG laser was applied with the same parameters as Group V. During laser application the teeth were always filled with irrigating solution. The fiber optic tip was introduced until the apex and the laser was activated. The tip was withdrawn gently with helicoidally movement from the apex until the pulp chamber. After preparation the teeth were immersed in 10% copper sulfate for 30 minutes, in vacuum for the first 5 minutes. The teeth were then placed in a 1% rubianic acid alcohol solution for the same periodsin solution and in vacuum as above. Upon completion of this reaction the teeth were sectioned transversally, in 150micrometers slices, and sanded, washed, dehydrated, cleared and mounted on glass slides for microscopic examination. The quantification of the penetration of copper ions was done by morphmetric analysis with a 400-point grid. The data was submitted

  9. Combating photooxidative stress in green hairy roots of Daucus carota cultivated under light irradiation.

    PubMed

    Mukherjee, Chiranjit; Sircar, Debabrata; Chatterjee, Moniya; Das, Sampa; Mitra, Adinpunya

    2014-01-15

    The light-dependent generation of active oxygen species, which can disrupt normal metabolic process of plant, is termed as photo-oxidative stress. Plants are equipped with enzymatic and non-enzymatic antioxidative defence system to reduce the effect of such stress. Hairy root culture of Daucus carota when cultivated under continuous illumination (250 μmol m(-2)s(-1)) turned green. To know the reason behind that and photo-oxidative stress response in green hairy roots, activities of several antioxidant enzymes were measured. When compared with normal hairy roots, green hairy roots showed an enhanced superoxide dismutase (SOD) activity. Treatment with a SOD inhibitor diethyldithiocarbamate led to suppression of SOD activity in a concentration-dependent manner in green hairy roots. Interestingly, SOD-suppressed root showed three-fold enhanced caffeic acid glucoside accumulation in the soluble fraction as compared to untreated ones. While ascorbate peroxidase activity showed marginal increase in green hairy roots, a decrease in the activities of guaiacol peroxidase and catalase were observed. SDS-PAGE of crude protein profile from green hairy roots showed a distinct band, which was absent in normal hairy roots. MALDI-TOF-MS/MS analysis of the extracted protein confirmed it as the large subunit of RuBisCO. RT-PCR based expression analysis of betaine aldehyde dehydrogenase showed enhanced transcript levels in green hairy roots as compared to normal hairy roots, whereas reverse trends were observed with the transcripts accumulation for phenylalanine ammonia-lyase and chalcone synthase. These findings corroborate with the in vitro BADH activities in hairy roots, and thus indicate an important role of this stress enzyme in combating photo-oxidative stress in green hairy roots upon continuous light exposure. Copyright © 2013 Elsevier GmbH. All rights reserved.

  10. Comparison of different dentin pretreatment protocols on the bond strength of glass fiber post using self-etching adhesive.

    PubMed

    Martinho, Frederico C; Carvalho, Claudio Antonio Talge; Oliveira, Luciane D; de Lacerda, Ana Júlia Farias; Xavier, Ana Cláudia Carvalho; Augusto, Marina Gullo; Zanatta, Rayssa Ferreira; Pucci, Cesar Rogerio

    2015-01-01

    This study compared the influence of different irrigants with and without ultrasound or laser irradiation on the bond strength of glass fiber posts using a self-etching adhesive in a supplementary dentin pretreatment. Ninety bovine incisor roots were divided into 3 groups according to the irrigant tested: 2% chlorhexidine (CHX) (n = 30); 2.5% sodium hypochlorite (NaOCl) (n = 30), and saline solution (control) (n = 30). Each group was randomly divided into 3 subgroups according to the supplementary dentin pretreatment: ultrasound, Nd:YAG laser, and nonsupplemented (control). A self-etching adhesive system (Futurabond DC; VOCO GmbH, Cuxhaven, Germany) was used, and the glass fiber posts were cemented with dual-cure epoxy-based luting agent (Bifix QM, VOCO GmbH). All roots were sectioned transversely, and the push-out test was performed. Failure mode analysis was also evaluated. Bond strength decreased significantly after the use of 2.5% NaOCl in all root thirds (P < .05). CHX showed no difference in the mean bond strength value compared with saline solution (P > .05). The supplementary dentin pretreatment using the Nd:YAG laser or ultrasound did not improve the bond strength values for both NaOCl and CHX (P > .05). Moreover, the apical third exhibited the lowest mean bond strength values (P < .05). Analysis indicated that the predominant failure mode was the mixed type. Regardless of the irrigant used, the supplementary dentin pretreatment with ultrasound or laser irradiation showed no improvement in bond strength. Also, the use of NaOCl decreased the bond strength of glass fiber posts using a self-etching adhesive system, whereas CHX preserved it. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  11. Permeability of Dentine

    PubMed Central

    Ghazali, Farid Bin Che

    2003-01-01

    This is an update on the present integrated knowledge regarding dentine permeability that assumed a role in dentine sensitivity and contribute clinically to the effective bonding properties of restorative dental materials. This paper will attempt to refer to in vivo and in vitro studies of dentine permeability and the various interrelated factors governing it. PMID:23365497

  12. [Dentin adhesives. An update].

    PubMed

    Grandini, R; Novelli, C; Pierleoni, P

    1991-11-01

    Even if mechanical bonding to enamel utilizing the acid-etch technique has been very successful, adhesion to dentin is still a challenge to researchers and clinicians. Dentin is a vital tissue and differs in composition from enamel: acid-etching does not enhance the bond strength of composite resins to dentin and may elicit a severe pulpal response. For an effective bond to occur, a dentin bonding system has to be used. The first generation of methacrylate-based dentin adhesives was capable of chemical bonding to the inorganic phase of dentin. The chemical basis for this resin-dentin adhesive was the interaction between a phosphate group attached to the methacrylate and the calcium ions on the dentin surface. This system yielded rather low bond strengths which were clinically unsatisfying. The second generation of dentin adhesives became available to the profession recently. Each of these new bonding systems use similar chemical composition for the same purpose of bonding with physicochemical interaction to the hard tooth tissues. All these systems contain a mild acid dentin conditioner to remove the smear layer and an aqueous resin containing primer to improve monomer penetration into the hydrophilic dentin surface. The second generation dentin bonding systems are extremely sensitive to variations upon the completeness of instructions and how accurately these are followed by dental practitioners.

  13. Permeability of dentine.

    PubMed

    Ghazali, Farid Bin Che

    2003-01-01

    This is an update on the present integrated knowledge regarding dentine permeability that assumed a role in dentine sensitivity and contribute clinically to the effective bonding properties of restorative dental materials. This paper will attempt to refer to in vivo and in vitro studies of dentine permeability and the various interrelated factors governing it.

  14. Dentin tubule occluding ability of dentin desensitizers.

    PubMed

    Han, Linlin; Okiji, Takashi

    2015-04-01

    To compare the dentin tubule-occluding ability of fluoroaluminocalciumsilicate-based (Nanoseal), calcium phosphate-based (Teethmate Desensitizer), resin-containing oxalate (MS Coat ONE) and diamine silver fluoride (Saforide) dentin desensitizers using artificially demineralized bovine dentin. Simulated hypersensitive dentin was created using cervical dentin sections derived from bovine incisors using phosphoric acid etching followed by polishing with a paste containing hydroxyapatite. The test desensitizers were applied in one, two, or three cycles, where each cycle involved desensitizer application, brushing, and immersion in artificial saliva (n= 5 each). The dentin surfaces were examined with scanning electron microscopy, and the dentin tubule occlusion rate was calculated. The elemental composition of the deposits was analyzed with electron probe microanalysis. Data were analyzed by one-way ANOVA and the Tukey honestly significant different test. Marked deposit formation was observed on the specimens treated with Nanoseal or Teethmate Desensitizer, and tags were detected in the specimens' dentin tubules. These findings became more prominent as the number of application cycles increased. The major elemental components of the tags were Ca, F, and Al (Nanoseal) and Ca and P (Teethmate Desensitizer). The tubule occlusion rates of MS Coat ONE and Saforide were significantly lower than those of Nanoseal and Teethmate Desensitizer (P< 0.05).

  15. Comparison of Push-out Bond Strength of Gutta-percha to Root Canal Dentin in Single-cone and Cold Lateral Compaction Techniques with AH Plus Sealer in Mandibular Premolars

    PubMed Central

    Mokhtari, Hadi; Rahimi, Saeed; Forough Reyhani, Mohammad; Galledar, Saeedeh; Mokhtari Zonouzi, Hamid Reza

    2015-01-01

    Background and aims. The single-cone technique has gained some popularity in some European countries. The aim of the present study was to compare the push-out bond strength of gutta-percha to root canal dentin with the single-cone and cold lateral compaction canal obturation techniques. Materials and methods. The root canals of 58 human mandibular premolars were prepared using modified crown-down technique with ProTaper rotary files up to #F3as a master apical file (MAF) and divided randomly into groups A and B based on canal obturation technique. In group A (n = 29) the root canals were obturated with single-cone technique with #F3(30/.09) ProTaper gutta-percha, which was matched with MAF in relation to diameter, taper and manufacturer; in group B (n = 29) the canals were obturated with gutta-percha using cold lateral compaction technique. In both groups AH plus sealer were used. After two weeks of incubation, three 2-mm slices were prepared at a distance of 2 mm from the coronal surface and push-out test was carried out. Data were analyzed with descriptive statistics using independent samples t-test. Results. There were statistically significant differences between two groups. The mean push-out bond strength was higher in group B (lateral compaction technique) compared to group A (single-cone technique; P < 0.05). Conclusion. Use of single-cone technique for obturation of root canals resulted in a lower bond strength compared to cold lateral compaction technique. PMID:26889358

  16. Nanoindentation hardness of intertubular dentin in sound, demineralized and natural caries-affected dentin.

    PubMed

    Joves, Gerardo José; Inoue, Go; Sadr, Alireza; Nikaido, Toru; Tagami, Junji

    2014-04-01

    The purpose of this study was to investigate the mechanical properties of intertubular dentin in sound, natural caries-affected (NCAD) and artificial caries-affected dentin (ACAD) using nanoindentation. Non-caries molars and caries molars with International Caries Detection and Assessment System (ICDAS II) score 5 at the occlusal site were used and caries was excavated using a spoon excavator, a round bur at low speed without water and a dye solution as guidance to detect the infected tissue. Specimens with remaining dentin thickness (RDT) >2mm were selected. ACAD teeth were created from sound teeth over 7 days in a demineralizing solution. Specimens were embedded into plastic rings with acrylic resin and then sagittal mesial-distal sectioned from crown to the long axis of the root under cooling water using a low-speed diamond blade. The surface of interest was fine polished sequentially. Hardness measurement was performed within an axial depth of 1000μm with at least of 320 indentations on each sample. Mann-Whitney U Test was used to compare the hardness as the variable among different dentin types (SOUND, NCAD and ACAD) at each dentin depth level. There was no significant difference in nanohardness between NCAD and ACAD up to a depth of 130μm (p>0.05). NCAD consistently showed lower hardness. ACAD showed no significant difference in hardness with SOUND dentin beyond 190μm (p<0.05). The lesion front in ACAD was considered to be located around the depth of 180μm. Natural and artificial caries-affected dentin tissues were superficially comparable in intertubular nanohardness. There is a certain layer within the natural caries-affected dentin with higher hardness; however the long-term effects of caries beneath the lesion extend deeply through intertubular dentin. Sound dentin at deep areas (close to the pulp chamber) is considered to be soft. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Dentin matrix protein 1 and phosphate homeostasis are critical for postnatal pulp, dentin and enamel formation

    PubMed Central

    Rangiani, Afsaneh; Cao, Zheng-Guo; Liu, Ying; Voisey Rodgers, Anika; Jiang, Yong; Qin, Chun-Lin; Feng, Jian-Quan

    2012-01-01

    Deletion or mutation of dentin matrix protein 1 (DMP1) leads to hypophosphatemic rickets and defects within the dentin. However, it is largely unknown if this pathological change is a direct role of DMP1 or an indirect role of phosphate (Pi) or both. It has also been previously shown that Klotho-deficient mice, which displayed a high Pi level due to a failure of Pi excretion, causes mild defects in the dentinal structure. This study was to address the distinct roles of DMP1 and Pi homeostasis in cell differentiation, apoptosis and mineralization of dentin and enamel. Our working hypothesis was that a stable Pi homeostasis is critical for postnatal tooth formation, and that DMP1 has an antiapoptotic role in both amelogenesis and dentinogenesis. To test this hypothesis, Dmp1-null (Dmp1−/−), Klotho-deficient (kl/kl), Dmp1/Klotho-double-deficient (Dmp1−/−/kl/kl) and wild-type (WT) mice were killed at the age of 6 weeks. Combinations of X-ray, microcomputed tomography (μCT), scanning electron microscopy (SEM), histology, apoptosis and immunohistochemical methods were used for characterization of dentin, enamel and pulp structures in these mutant mice. Our results showed that Dmp1−/− (a low Pi level) or kl/kl (a high Pi level) mice displayed mild dentin defects such as thin dentin and a reduction of dentin tubules. Neither deficient mouse line exhibited any apparent changes in enamel or pulp structure. However, the double-deficient mice (a high Pi level) displayed severe defects in dentin and enamel structures, including loss of dentinal tubules and enamel prisms, as well as unexpected ectopic ossification within the pulp root canal. TUNEL assay showed a sharp increase in apoptotic cells in ameloblasts and odontoblasts. Based on the above findings, we conclude that DMP1 has a protective role for odontoblasts and ameloblasts in a pro-apoptotic environment (a high Pi level). PMID:23258378

  18. Dentinal permeation modeling

    NASA Astrophysics Data System (ADS)

    Trunina, Natalia; Derbov, Vladimir; Tuchin, Valery; Altshuler, Gregory

    2008-06-01

    Dentinal permeation is of interest in a wide context of tooth care and treatment, in particular, tooth color improvement using combination of chemical whitening agents and light activation. A simple model of dentinal permeation accounting for the morphology of human tooth dentine and including dentinal tubules, more dense and homogeneous peritubular dentine, and less dense and less homogeneous intertubular dentin is proposed. Calculation of permeability of dentine layer is carried out for H IIO and H IIO II versus the tubule diameter and tubule density taken from the microphotograph analysis. This opens the possibility to calculate the distribution of permeability over the tooth surface taking into account the variations of tubule diameter and density as well as those of the diffusion coefficients and layer thickness

  19. Effect of Water-Cooled Nd:YAG Laser on Dentinal Tubule Occlusion In Vitro.

    PubMed

    Xiao, Shimeng; Liang, Kunneng; Liu, Hongling; Zhang, Manling; Yang, Heng; Guo, Shujuan; Ding, Yi

    2017-02-01

    The objective of this study was to investigate the effect of a new water-cooled Nd:YAG laser on dentinal tubule occlusion. The effect of water-cooled Nd:YAG laser on dentinal tubule occlusion has not been reported. Acid-etched dentin samples were randomly divided into three groups: (1) dentin control, (2) dentin treated by Nd:YAG laser, (3) dentin treated by water-cooled Nd:YAG laser. After laser irradiation, half of the samples were immersed in a 6 wt% citric acid (pH 1.5) solution for 1 min to evaluate the acid resistance. The morphologies of dentin surfaces were characterized by scanning electron microscopy. The number and diameters of the open dentinal tubules were analyzed by one-way and two-way analyses of variance. Both the Nd:YAG laser and water-cooled Nd:YAG laser melted the superficial layer of dentin, which caused dentinal tubule occlusion in most areas and diameter reduction of the rest open tubules. Microcracks on the dentin surface were only observed in the Nd:YAG laser group. The tubule occlusion induced by the two lasers showed a good acid resistance. The effect of water-cooled Nd:YAG laser on dentinal tubule occlusion is similar to that of the Nd:YAG laser. The dentinal tubule occlusion induced by the two lasers could resist acid challenge to some extent.

  20. Bovine dentine organic matrix down-regulates osteoclast activity.

    PubMed

    Sriarj, Wantida; Aoki, Kazuhiro; Ohya, Keiichi; Takagi, Yuzo; Shimokawa, Hitoyata

    2009-01-01

    Physiological root resorption is a phenomenon that normally takes place in deciduous teeth; root resorption of permanent teeth occurs only under pathological conditions. The molecular mechanisms underlying these processes are still unclear. Our previous study showed that osteoclasts cultured on deciduous dentine exhibited a higher degree of resorption and higher levels of cathepsin K and MMP-9 mRNA than osteoclasts cultured on permanent dentine. These results could be because of different susceptibilities to acid and the different organic matrices between deciduous and permanent dentine. Thus, the purpose of this study was to investigate the effect of dentine extracts from bovine deciduous and permanent dentine on osteoclast activity. Osteoclasts, obtained from mouse bone marrow cells co-cultured with an osteoblast-rich fraction in the presence of 1,25-(OH)(2)-vitamin D3 and PGE2, were incubated with or without 0.6 M HCl extracts from bovine deciduous or permanent dentine for 48 h. TRAP positive cell number, TRAP activity, the areas of resorption pits, and mRNA levels of TRAP, v-ATPase, calcitonin receptor, cathepsin K, and MMP-9 were examined. The results illustrated that TRAP activity, the resorbed area, and the mRNA levels of osteoclast marker genes seemed to be suppressed by both deciduous and permanent dentine extracts. These findings indicate that some factors that suppress osteoclast activity are contained in both deciduous and permanent dentine extracts. Although there was no significant difference in osteoclast activity between deciduous and permanent dentine extracts, osteoclasts incubated with permanent dentine extracts tend to exhibit less resorption activity than those incubated with deciduous dentine extracts. However, we could not clearly explain the causes of this.

  1. Mesenchymal dental pulp cells attenuate dentin resorption in homeostasis.

    PubMed

    Zheng, Y; Chen, M; He, L; Marão, H F; Sun, D M; Zhou, J; Kim, S G; Song, S; Wang, S L; Mao, J J

    2015-06-01

    Dentin in permanent teeth rarely undergoes resorption in development, homeostasis, or aging, in contrast to bone that undergoes periodic resorption/remodeling. The authors hypothesized that cells in the mesenchymal compartment of dental pulp attenuate osteoclastogenesis. Mononucleated and adherent cells from donor-matched rat dental pulp (dental pulp cells [DPCs]) and alveolar bone (alveolar bone cells [ABCs]) were isolated and separately cocultured with primary rat splenocytes. Primary splenocytes readily aggregated and formed osteoclast-like cells in chemically defined osteoclastogenesis medium with 20 ng/mL of macrophage colony-stimulating factor (M-CSF) and 50 ng/mL of receptor activator of nuclear factor κB ligand (RANKL). Strikingly, DPCs attenuated osteoclastogenesis when cocultured with primary splenocytes, whereas ABCs slightly but significantly promoted osteoclastogenesis. DPCs yielded ~20-fold lower RANKL expression but >2-fold higher osteoprotegerin (OPG) expression than donor-matched ABCs, yielding a RANKL/OPG ratio of 41:1 (ABCs:DPCs). Vitamin D3 significantly promoted RANKL expression in ABCs and OPG in DPCs. In vivo, rat maxillary incisors were atraumatically extracted (without any tooth fractures), followed by retrograde pulpectomy to remove DPCs and immediate replantation into the extraction sockets to allow repopulation of the surgically treated root canal with periodontal and alveolar bone-derived cells. After 8 wk, multiple dentin/root resorption lacunae were present in root dentin with robust RANKL and OPG expression. There were areas of dentin resoprtion alternating with areas of osteodentin formation in root dentin surface in the observed 8 wk. These findings suggest that DPCs of the mesenchymal compartment have an innate ability to attenuate osteoclastogenesis and that this innate ability may be responsible for the absence of dentin resorption in homeostasis. Mesenchymal attenuation of dentin resorption may have implications in internal

  2. Mesenchymal Dental Pulp Cells Attenuate Dentin Resorption in Homeostasis

    PubMed Central

    Zheng, Y.; Chen, M.; He, L.; Marão, H.F.; Sun, D.M.; Zhou, J.; Kim, S.G.; Song, S.; Wang, S.L.

    2015-01-01

    Dentin in permanent teeth rarely undergoes resorption in development, homeostasis, or aging, in contrast to bone that undergoes periodic resorption/remodeling. The authors hypothesized that cells in the mesenchymal compartment of dental pulp attenuate osteoclastogenesis. Mononucleated and adherent cells from donor-matched rat dental pulp (dental pulp cells [DPCs]) and alveolar bone (alveolar bone cells [ABCs]) were isolated and separately cocultured with primary rat splenocytes. Primary splenocytes readily aggregated and formed osteoclast-like cells in chemically defined osteoclastogenesis medium with 20 ng/mL of macrophage colony-stimulating factor (M-CSF) and 50 ng/mL of receptor activator of nuclear factor κB ligand (RANKL). Strikingly, DPCs attenuated osteoclastogenesis when cocultured with primary splenocytes, whereas ABCs slightly but significantly promoted osteoclastogenesis. DPCs yielded ~20-fold lower RANKL expression but >2-fold higher osteoprotegerin (OPG) expression than donor-matched ABCs, yielding a RANKL/OPG ratio of 41:1 (ABCs:DPCs). Vitamin D3 significantly promoted RANKL expression in ABCs and OPG in DPCs. In vivo, rat maxillary incisors were atraumatically extracted (without any tooth fractures), followed by retrograde pulpectomy to remove DPCs and immediate replantation into the extraction sockets to allow repopulation of the surgically treated root canal with periodontal and alveolar bone–derived cells. After 8 wk, multiple dentin/root resorption lacunae were present in root dentin with robust RANKL and OPG expression. There were areas of dentin resoprtion alternating with areas of osteodentin formation in root dentin surface in the observed 8 wk. These findings suggest that DPCs of the mesenchymal compartment have an innate ability to attenuate osteoclastogenesis and that this innate ability may be responsible for the absence of dentin resorption in homeostasis. Mesenchymal attenuation of dentin resorption may have implications in internal

  3. 1064-nm Nd:YAG and 980-nm Diode Laser EDTA Agitation on the Retention of an Epoxy-Based Sealer to Root Dentin.

    PubMed

    Macedo, Helena Suleiman de; Messias, Danielle Cristine Furtado; Rached-Júnior, Fuad Jacob; Oliveira, Ligia Teixeira de; Silva-Sousa, Yara Teresinha Correa; Raucci-Neto, Walter

    2016-01-01

    Root canal irrigants are used to minimize the negative effects of smear layer on endodontic sealer retention. The aim of this study was to evaluate the efficacy of agitation of 17% ethylenediaminetetraacetic acid (EDTA) with ultrasonic, 1064-nm Nd:YAG and 980-nm diode laser on the retention of an epoxy-based sealer to the root canal walls. Forty single-rooted bovine teeth were instrumented with ProTaper rotary system and divided into four groups according to the final irrigation protocol (n = 10): (1) 17% EDTA (control); (2) 17% EDTA with 50-s ultrasonic agitation; (3) 17% EDTA with 50-s diode laser (2-W) agitation; and (4) 17% EDTA with 50-s Nd:YAG (1.5-W) laser agitation. After endodontic filling with gutta-percha F5 master cone and Sealer 26, the roots were sectioned at the cervical, middle, and apical root thirds to obtain 1.5-mm slices. Push-out tests were performed using a universal testing machine at a 1 mm/min crosshead speed. Data were analyzed using two-way ANOVA and Tukey's tests (α=0.05). Apical root thirds had significant higher retention values than cervical and middle thirds (p < 0.05). EDTA with 1064-nm Nd:YAG or 980-nm diode laser presented the highest retention values and was significantly different from EDTA with ultrasonic agitation and EDTA only (p < 0.05). Adhesive failures were predominant to EDTA only group. Mixed failures were predominant to all agitation groups. 1064-nm Nd:YAG and 980-nm diode laser EDTA agitation enhanced the retention of the epoxy-based sealer to the root canal walls compared with that due to EDTA only or EDTA with ultrasonic agitation.

  4. Study suggests dentine bonding agents provided better relief from dentine hypersensitivity than a desensitising toothpaste.

    PubMed

    Lamont, Thomas; Innes, Nicola

    2013-12-01

    Randomised, controlled, single-blind, three-arm parallel-group trial set in general dental practice with a single general dental practitioner operator/assessor. Seventy-five adult patients, with basic periodontal examination scores of 0 in all sextants, good oral hygiene, at least one sensitive tooth (not diagnosed as pulpitis) and willing to comply with the trial regime were entered into the trial and randomised. Seventy-two participants completed the study. The three interventions were; non-desensitising toothpaste (Colgate Cavity Protection Regular, Colgate-Palmolive, USA), desensitising toothpaste (Colgate Sensitive Fresh Stripe, Colgate-Palmolive, USA) and dentine bonding agent (Seal and Protect, Denpsly, USA). The non-desensitising toothpaste and desensitising toothpastes were provided to the subjects for use at home but dentine bonding agent was applied in the surgery. Dentinal hypersensitivity was measured using a participant completed Visual Analogue Scale (VAS) at baseline, two weeks, three months and six months. At baseline and six months a standardised air blast to the buccal cervical root stimulus was used with the VAS. At two weeks and at three months participants self-completed the VAS at home with no stimulus. Although there was a reduction in dentinal hypersensitivity over time for all three groups, dentinal hypersensitivity reduced significantly (p<0.0001) in both desensitising toothpaste and dentine bonding agent groups. The mean VAS scores in the dentine bonding agent group were statistically significantly lower when compared to both non-desensitising toothpaste (p<0.001) and desensitising toothpaste (p<0.001). In addition, mean scores for non-desensitising toothpaste were higher than desensitising toothpaste (p<0.05). Dentine bonding agents provided the greatest improvement in dentinal hypersensitivity at two weeks and six months. This reduction was greater than that achieved with the desensitising and non-desensitising toothpastes tested.

  5. Bactericidal effect of the 908 nm diode laser on Enterococcus faecalis in infected root canals

    PubMed Central

    Preethee, Thomas; Kandaswamy, Deivanayagam; Arathi, Ganesh; Hannah, Rosaline

    2012-01-01

    Aim: The aim of this study is to evaluate the bactericidal effect of 908 nm diode laser in conjunction with various irrigation regimes in disinfection of apical third of root dentin. Materials and Methods: Sixty prepared teeth with single canals were contaminated with Enterococcus faecalis. The specimens were divided into 6 groups (n = 10): Group 1 and 3 and 5 were subjected to chemo-mechanical preparation using 5.25% sodium hypochlorite (NaOCl), 17% Ethylenediaminetetraacetic acid (EDTA); 1.3% NaOCl, MTAD (mixture of doxycycline, citric acid and a detergent (Tween 80); and, 8.5% saline, respectively followed by 908 nm diode laser irradiation; Group 2 and 4, followed the same procedure as Group1 and 3, however without laser irradiation; and, Group 6, rinsed with saline solution (control). Dentin shavings from apical third were analyzed for the presence of E. faecalis using culture method and Polymerase Chain reaction (PCR). Results: One-way Analysis of variance showed statistically significant differences between the laser irradiated groups, non irradiated groups and the control group. Conclusion: 908 nm diode used in conjunction with conventional chemomechanical techniques demonstrated a significant elimination of E. faecalis in the apical third of root dentin. PMID:22368335

  6. Detection of dentinal microcracks using infrared thermography.

    PubMed

    Matsushita-Tokugawa, Manami; Miura, Jiro; Iwami, Yukiteru; Sakagami, Takahide; Izumi, Yui; Mori, Naoya; Hayashi, Mikako; Imazato, Satoshi; Takeshige, Fumio; Ebisu, Shigeyuki

    2013-01-01

    It is difficult to make a definite diagnosis of a cracked tooth solely based on an inspection within the root canal, especially in case of microcracks. At present, there seems to be no established method to detect dentinal microcracks in roots; therefore, the current detection techniques need to be improved. Vibrothermography (VibroIR) helps to detect microcracks by the friction heat generated from ultrasonic vibration. The purpose of this study was to establish a novel method using VibroIR to detect dentinal microcracks. The root canals of 20 roots with cracks and control roots were prepared after removing the tooth crowns. A tapered indenter was inserted into the root canal and pressed until a microcrack was created under an optical microscope. Using VibroIR, the detection trials for dentinal microcracks were performed with an ultrasonic vibration power ranging from 0.43 to 1.48 W at an angle of 0°, 30°, 45°, 60°, and 90° between the ultrasonic vibration point and the microcrack line. After the detection test, the microcrack width was measured with an optical microscope. Frictional heat was detected in the microcracks with thermography at 0.89 to 1.48 W and at an ultrasonic vibration point angle less than 60° from the crack line for 10 seconds. Microcracks with a width of 4 to 35.5 μm were detected with this method. VibroIR may be an effective method for the diagnosis of root dentinal microcracks. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  7. Effect of phosphate-buffered saline on push-out bond strength of a new bioceramic sealer to root canal dentin

    PubMed Central

    Shokouhinejad, Noushin; Hoseini, Atefeh; Gorjestani, Hedayat; Raoof, Maryam; Assadian, Hadi; Shamshiri, Ahmad Reza

    2012-01-01

    Background: The aim of this study was to compare push-out bond strength of a new bioceramic endodontic sealer, EndoSequence BC sealer (Brasseler USA, Savannah, GA), used with gutta-percha in the presence or absence of phosphate-buffered saline solution (PBS) within the root canals. Materials and Methods: Forty single-rooted human teeth were prepared and randomly divided into four groups. Samples in groups 1 and 2 were dried, but those in groups 3 and 4 were moistened with PBS before obturation. All root canals were obturated with gutta-percha/EndoSequence BC sealer. The specimens were stored in PBS for 7 days in groups 1 and 3 and for 2 months in groups 2 and 4. Push-out bond strength values and failure modes were evaluated. The data on push-out bond strength were analyzed using two-way ANOVA. Results: The mean value for the bond strength of the obturation material in moistened canals was significantly higher than that in dried ones at 1 week (P = 0.00). Contrarily, there was no significant difference between dried and moistened root canals at 2 months (P = 0.61). In dried canals, bond strength increased significantly with time but in moistened ones, the difference was not significant. Inspection of the specimens revealed the bond failure to be mainly cohesive for all groups. Conclusion: The presence of PBS within the root canals increased the bond strength of EndoSequence BC sealer/gutta-percha at 1 week. However, no difference was found between the bond strength of EndoSequence BC sealer/gutta-percha in the presence or absence of PBS in the root canals at 2 months. PMID:235