Effect of erosive challenges on deciduous teeth undergoing restorative procedures with different adhesive protocols - an in vitro study.

PubMed

Assunção, Cristiane Meira; Goulart, Marcelo; Essvein, Tattiana Enrich; Santos, Nicole Marchioro Dos; Erhardt, Maria Carolina Guilherme; Lussi, Adrian; Rodrigues, Jonas de Almeida

2018-01-18

To evaluate the effect of erosive challenges on the tooth- restoration interface of deciduous teeth treated with different adhesive protocols. Deciduous molars were cut mesiodistally, then embedded, abraded and polished (n=80). Samples were randomly divided according to the adhesive system used into: G1 (Adper Single Bond2®, etch-and-rinse), G2 (Universal Single Bond®, self-etching), G3 (OptibondFL®, etch-and-rinse with Fluoride) and G4 (BondForce®, self-etching with Fluoride). After standardized cavity preparation (2 mm diameter x 2 mm depth), adhesive systems were applied and samples were restored (composite resin Z350®). Half of the samples were exposed to erosive/abrasive cycles (n = 10, each adhesive group), and the other half (control group; n = 10) remained immersed in artificial saliva. For microleakage analysis, samples were submersed in methylene blue and analyzed at 40x magnifications. Cross-sectional microhardness (CSMH) was carried out (50 g/5 s) at 25 μm, 50 μm, and 100 μm from the eroded surface and at 25 μm, 75 μm, and 125 μm from the enamel bond interface. Regarding microleakage, 7.5% of the samples showed no dye infiltration, 30% showed dye infiltration only at the enamel interface, and 62.5% showed dye infiltration through the dentin-enamel junction, with no difference between groups (p≥0.05). No significant difference was observed in CSMH at different depths (two-way ANOVA, p≥0.05). We did not observe significant changes in microleakage or CSMH after erosive/abrasive challenges in deciduous teeth treated with different adhesive protocols (etch-and-rinse and self-etching adhesives, with and without fluoride).

In-vitro comparison of instrumentation time and cleaning capacity between endodontic handpiece and manual preparation techniques in primary molar teeth.

PubMed

Seraj, B; Ramezani, G; Ghadimi, S; Mosharrafian, S H; Motahhary, P; Safari, M

2013-01-01

The aim of this study was to evaluate and compare the cleaning ability and instrumentation time of manual method and use of endodontic handpiece for preparation of primary molar teeth. Forty primary teeth canals were used in this experimental study. Access cavities were prepared and India ink was injected into the canals. The samples were divided into three groups according to the preparation technique. In the first group the root canals were manually instrumented by k_files. Endodontic handpiece (TEP-ER10, NSK, Japan) were used for canal preparation in the second group and the samples in the third group (control) were not instrumented. After preparing the canal, the teeth were cleared with methyl salicylate and the removal of India ink was measured in the cervical, middle and apical thirds. The instrumentation time was transcribed by chronometer. Statistical analysis was performed using Mann-Whitney and t-test. There was no significant difference in cleaning capacity between the two techniques, but results of the first and second group differ from those of the control group. In fact, time taken for preparation was significantly shorter with endodontic handpiece system. Seen the shorter working time of endodontic handpiece and the similar cleaning ability of the two techniques, the application of the endodontic handpiece is recommended for preparation of deciduous root canals during pulpectomy.

Teething troubles?

PubMed

McIntyre, G T; McIntyre, G M

2002-03-09

The relationship between the eruption of the deciduous teeth and the general health of infants has been documented for over 5,000 years. A variety of physical disturbances (anything from minor upsets to potentially fatal illnesses) have historically been attributed to teething, however a number of recent publications have alluded to a clarification of some of the disputed features of teething. It is now accepted that the localised symptoms of teething vary between individuals, however, 'teething' continues to be an inappropriate diagnosis proffered by both healthcare professionals and lay people. Severe systemic upsets are unrelated to teething and, if present, the infant should be promptly referred to a physician for an accurate diagnosis and appropriate treatment. The treatment modalities used in teething have been diverse throughout the ages, frequently depending on the tenets of the medical profession and lay people, but now principally involve pain relief. This article examines the signs and symptoms frequently attributed to teething and their possible alternative causes. The contemporary principles of the management of teething are discussed, including supportive measures, the diverse range of available topical and systemic pharmacological preparations and the 'alternative' holistic therapies.

Management of a rare case of idiopathic multiple unerupted impacted permanent teeth in an adult female patient

PubMed Central

Shetty, Karunakar; Kumar, Mahesh; Amanna, Susan; Sridharan, Srirangarajan; Reddy, Satyanarayan

2016-01-01

This clinical case report describes the multi-disciplinary approach in the management of an unusual presentation of idiopathic multiple unerupted impacted permanent teeth in a 20-year-old female patient. The case was unique in that, not only were there multiple missing permanent teeth, but also over retained deciduous teeth and attrited existing permanent teeth with loss of vertical dimension of occlusion. Since the patient was young, it was decided to retain all the erupted permanent teeth and extract the infected deciduous teeth with the objective of fabricating overlay complete dentures. This is a simple, reversible and an economical treatment modality, which satisfies both the esthetic and functional demands where the extraction of teeth is not generally indicated and, in addition, provides a stable occlusion. PMID:27621553

Correction to: Stem Cells from Human Exfoliated Deciduous Teeth Modulate Early Astrocyte Response after Spinal Cord Contusion.

PubMed

Nicola, Fabrício; Marques, Marília Rossato; Odorcyk, Felipe; Petenuzzo, Letícia; Aristimunha, Dirceu; Vizuete, Adriana; Sanches, Eduardo Farias; Pereira, Daniela Pavulack; Maurmann, Natasha; Gonçalves, Carlos-Alberto; Pranke, Patricia; Netto, Carlos Alexandre

2018-06-16

The authors hereby declare that the Figure 4 in page eight of the paper "Stem cells from human exfoliated deciduous teeth modulate early astrocyte response after spinal cord contusion" authored by Fabrício Nicola and colleagues (DOI: 10.1007/s12035-018-1127-4) was mistakenly included.

[Investigation of status of dental caries in children of primary school in Hangzhou city from 2009 to 2011].

PubMed

Hu, Qi-yong; Liu, Min; Wang, Ren-fei; Li, Xiao-feng; Jing, Chang; Tian, Xiao-hua

2013-04-01

To investigate the status of dental caries in children of primary school in Hangzhou City from 2009 to 2011. The status of dental caries was examined annually from 2009 to 2011, and the caries prevalence, filling rates, mean DMFT/dmft were recorded. SPSS 13.0 software package was used for statistical analysis. From 2009 to 2011, the caries prevalence of deciduous teeth were 49.27%, 48.09% and 48.33%, mean dmft were 2.78, 2.81 and 2.84, filling rates of deciduous teeth were 3.92%, 4.31% and 4.28%, respectively. No significant difference was found in the caries prevalence of temporary teeth, filling rates of temporary teeth, mean dmft. For the permanent teeth, the caries prevalence were 20.24%, 18.48% and 15.85%, mean DMFT were 0.46, 0.41 and 0.33, filling rates were 10.17%, 15.67% and 23.00%, respectively. From 2009 to 2011, the caries prevalence and mean DMFT of permanent teeth was decreased, while the filling rate was increased. In the past three years, the status of dental caries of permanent teeth shows a remarkable improving tendency in children of primary school in Hangzhou City. However, the status of dental caries of deciduous teeth presents no significant improvement.

CCL3 and CXCL12 production in vitro by dental pulp fibroblasts from permanent and deciduous teeth stimulated by Porphyromonas gingivalis LPS

PubMed Central

SIPERT, Carla Renata; MORANDINI, Ana Carolina de Faria; MODENA, Karin Cristina da Silva; DIONÍSIO, Thiago José; MACHADO, Maria Aparecida Andrade Moreira; de OLIVEIRA, Sandra Helena Penha; CAMPANELLI, Ana Paula; SANTOS, Carlos Ferreira

2013-01-01

Objective: The aim of this study was to compare the production of the chemokines CCL3 and CXCL12 by cultured dental pulp fibroblasts from permanent (PDPF) and deciduous (DDPF) teeth under stimulation by Porphyromonas gingivalis LPS (PgLPS). Material and Methods: Primary culture of fibroblasts from permanent (n=3) and deciduous (n=2) teeth were established using an explant technique. After the fourth passage, fibroblasts were stimulated by increasing concentrations of PgLPS (0 - 10 µg/mL) at 1, 6 and 24 h. The cells were tested for viability through MTT assay, and production of the chemokines CCL3 and CXCL12 was determined through ELISA. Comparisons among samples were performed using One-way ANOVA for MTT assay and Two-way ANOVA for ELISA results. Results: Cell viability was not affected by the antigen after 24 h of stimulation. PgLPS induced the production of CCL3 by dental pulp fibroblasts at similar levels for both permanent and deciduous pulp fibroblasts. Production of CXCL12, however, was significantly higher for PDPF than DDPF at 1 and 6 h. PgLPS, in turn, downregulated the production of CXCL12 by PDPF but not by DDPF. Conclusion: These data suggest that dental pulp fibroblasts from permanent and deciduous teeth may present a differential behavior under PgLPS stimulation. PMID:23739851

PCR-based identification of selected pathogens associated with endodontic infections in deciduous and permanent teeth.

PubMed

Cogulu, Dilsah; Uzel, Atac; Oncag, Ozant; Eronat, Cemal

2008-09-01

The aim of the present study was to evaluate the presence of the selected pathogens in samples from deciduous and permanent tooth root canals by using PCR method and to determine the association of these organisms with clinical symptoms. A total of 145 children, 5 to 13 years old, were involved in this study. The presence of selected pathogens (Actinomyces israelii, Candida albicans, Enterococcus faecalis, Fusobacterium nucleatum, Porphyromonas endodontalis, Porphyromonas gingivalis, Prevotella intermedia, Streptococcus intermedius, Treponema denticola, Parvimonas micra, Tannerella forsythensis, Enterococcus faecium, Prevotella melaninogenica) in infected root canals was studied using PCR. T. denticola (P = .012, .02) and E. faecalis (P = .012, .04) were highly associated with periapical radiolucency and previous pain, while P. gingivalis was associated with tenderness to percussion in both deciduous and permanent teeth (P = .01, .015). The results of the present study confirm that certain species of microorganisms are associated with clinical signs and symptoms of endodontic disease in both deciduous and permanent teeth.

Deciduous tooth size standards for American blacks.

PubMed

Vaughan, M D; Harris, E F

1992-10-01

Normative standards for tooth sizes are valuable for assessing a given patient's status, both clinically and for evaluating intrinsic (e.g., genetic, chromosomal aberrations) and acquired conditions. There are, however, very few published standards for American Blacks and none for the deciduous teeth. Mesiodistal and buccolingual crown diameters are reported here for a series of 100 Black children. As with the permanent dentition, the primary teeth of Blacks are appreciably larger than Whites, though the amount differs by tooth type. In general, while all teeth are larger than norms for Whites, the posterior teeth (m1, m2) are preferentially larger. Applications of these standards are discussed.

Clinical signs and bacterial communities of deciduous necrotic root canals detected by PCR-DGGE analysis: research association.

PubMed

de Paula, Viviane Andrade Cancio; de Carvalho Ferreira, Dennis; Cavalcante, Fernanda Sampaio; do Carmo, Flávia Lima; Rosado, Alexandre Soares; Primo, Laura Guimarães; dos Santos, Kátia Regina Netto

2014-08-01

This study sought to investigate the possible association between clinical and radiographic data of the patients with the bacterial community profiles involved in cases of necrosis in primary root canals. Microbial community profiles for 25 samples from necrotic deciduous root canals were analyzed using the polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) fingerprinting approach. These results were related to the clinical and radiographic data of these patients. The analysis showed a large diversity of microbial communities in necrotic deciduous root canals. The statistical results pointed out that posterior and anterior teeth were associated with <20 bands and >20 bands in PCR-DGGE method, respectively. A relationship was verified between ages >4 years old and posterior teeth and, ages ≤4 years old and anterior teeth. The data showed a polymicrobial community and pointed out the association of age with necrosis in anterior and posterior teeth. Copyright © 2014 Elsevier Ltd. All rights reserved.

Abnormalities of tooth development in pituitary dwarfism.

PubMed

Kosowicz, J; Rzymski, K

1977-12-01

Roentgenographic studies of the jaws and teeth in a group of forty-eight pituitary dwarfs showed the following abnormalities in the development of the teeth: 1. Delayed shedding of the deciduous teeth. 2. Absence of resorption of the roots of the deciduous teeth at the usual time. 3. Marked delay in eruption of the permanent teeth. 4. Retention of permanent teeth in the maxillary and mandibular shafts. 5. Development of the apical parts of roots of the retained permanent teeth and their growth toward the lower mandibular edge. 6. Displacement of the first molars from the mandibular shaft to rami. 7. Tilting of some of the retained teeth. 8. Small size of the maxilla and mandible with overcrowding of the teeth in these bones. 9. Complete absence of buds of the wisdom teeth, even in patients in the fourth decade of life. 10. Stimulation of development and eruption of the teeth after administration of anabolic drugs. These abnormalities when present in combination depend on growth hormone deficiency since they do not occur in other types of dwarfism.

Canadian Eskimo permanent tooth emergence timing.

PubMed

Mayhall, J T; Belier, P L; Mayhall, M F

1978-08-01

To identify the times of emergence of the permanent teeth of Canadian Eskimos (Inuit), 368 children and adolescents were examined. The presence or absence of all permanent teeth except the third molars was recorded and these data subjected to probit analysis. Female emergence times were advanced over males. Generally, the Inuit of both sexes showed statistically significant earlier emergence times than Montreal children, except for the incisors. The present results do not support hypotheses indicating that premature extraction of the deciduous teeth advances the emergence of their succedaneous counterparts. There is some indication the controls of deciduous tooth emergence continue to play some part in emergence of the permanent dentition, especially the first permanent teeth that emerge.

Strontium-90 in deciduous teeth as a factor in early childhood cancer.

PubMed

Gould, J M; Sternglass, E J; Sherman, J D; Brown, J; McDonnell, W; Mangano, J J

2000-01-01

Strontium-90 concentrations in deciduous (baby) teeth of 515 children born mainly after the end of worldwide atmospheric nuclear bomb tests in 1980 are found to equal the concentrations in children born during atmospheric tests in the late 1950s. Recent Sr-90 concentrations in the New York-New Jersey-Long Island metropolitan area have exceeded the expected downward trend seen in both baby teeth and adult bone after the 1963 ban on atmospheric testing. Sharp rises and declines are also seen in Miami, Florida. In Suffolk County, Long Island, Sr-90 concentrations in baby teeth were significantly correlated with cancer incidence for children 0 to 4 years of age. A similar correlation of childhood malignancies with the rise and decline of Sr-90 in deciduous teeth occurred during the peak years of fallout in the 1950s and 1960s. Independent support for the relation between nuclear releases and childhood cancer is provided by a significant correlation with total alpha and beta activities in local surface water in Suffolk County. These results strongly support a major role of nuclear reactor releases in the increase of cancer and other immune-system-related disorders in young American children since the early 1980s.

Allogeneic stem cells derived from human exfoliated deciduous teeth (SHED) for the management of periapical lesions in permanent teeth: Two case reports of a novel biologic alternative treatment

PubMed Central

Prasad, Madu Ghana Shyam; Ramakrishna, Juvva; Babu, Duvvi Naveen

2017-01-01

Stem cells are the pluripotent cells that have the capacity to differentiate into other specialized cells. Recently, many experiments have been conducted to study the potentiality of stem cells in the tissue regeneration. We report two cases treated utilizing stem cells from human exfoliated deciduous teeth (SHED) in the management of periapical lesions in permanent teeth. Two normal human deciduous teeth from children, 7‒8 years of age, were collected to isolate stem cells. Two patients, one with periapical pathology alone and the other with periapical lesion along with an open apex in young permanent teeth, were selected for the study. After initial debridement of the root canals, homing of SHED was carried out and the access cavity was sealed using glass-ionomer cement. Clinical examination after 7 days, 30 days, 90 days, 180 days and 365 days revealed no symptoms. Closure of open apex and periapical tissue healing were observed radiographically at one-month review and maintained until 365-day review. Positive response to electric pulp testing was recorded for the treated teeth from the 3- to 12-month follow-ups. The treated cases demonstrated complete resolution of periapical radiolucency in a span of 30 days, which was faster than the conventional methods. SHED could be considred effective in treating the periapical lesions and open apex in permanent teeth. PMID:28748053

The Effect of Multiple Sulfatase Deficiency (MSD) on Dental Development: Can We Use the Teeth as an Early Diagnostic Tool?

PubMed

Zilberman, Uri; Bibi, Haim

2016-01-01

Multiple sulfatase deficiency (MSD) is a rare autosomal recessive inborn error of metabolism due to reduced catalytic activity of the different sulfatase. Affected individuals show neurologic deterioration with mental retardation, skeletal anomalies, organomegaly, and skin changes as in X-linked ichthyosis. The only organ that was not examined in MSD patients is the dentition. To evaluate the effect of the metabolic error on dental development in a patient with the intermediate severe late-infantile form of MSD (S155P). Histological and chemical study were performed on three deciduous and five permanent teeth from MSD patient and pair-matched normal patients. Tooth germ size and enamel thickness were reduced in both deciduous and permanent MSD teeth, and the scalloping feature of the DEJ was missing in MSD teeth causing enamel to break off from the dentin. The mineral components in the enamel and dentin were different. The metabolic error insults the teeth in the stage of organogenesis in both the deciduous and permanent dentition. The end result is teeth with very sharp cusp tips, thin hypomineralized enamel, and exposed dentin due to the break off of enamel. These findings are different from all other types of MPS syndromes.Clinically the phenotype of intermediate severe late-infantile form of MSD appeared during the third year of life. In children of parents that are carriers, we can diagnose the disease as early as birth using X-ray radiograph of the anterior upper region or as early as 6-8 months when the first deciduous tooth erupt and consider very early treatment to ameliorate the symptoms.

Hardness and modulus of elasticity of primary and permanent teeth after wear against different dental materials

PubMed Central

Galo, Rodrigo; Contente, Marta Maria Martins Giamatei; Galafassi, Daniel; Borsatto, Maria Cristina

2015-01-01

Objectives: The purpose of this study was to determine the Young's modulus and the hardness of deciduous and permanent teeth following wear challenges using different dental materials. Materials and Methods: Wear challenges were performed against four dental materials: A resin-based fissure sealant (Fluoroshield®), a glass ionomer based fissure sealant (Vitremer®), and two microhybrid composite resins (Filtek Z250 and P90®). Using the pin-on-plate design, a deciduous or a permanent tooth was made into a pin (4 mm × 4 mm × 2 mm) working at a 3 N vertical load, 1 Hz frequency, and 900 cycles (15 min) with Fusayama artificial saliva as a lubricant. Before and after the tribological tests, the hardness and elasticity modulus of the tooth samples were measured by creating a nanoindentation at load forces up to 50 mN and 150 mN. All of the results were statistically analyzed using ANOVA and post-hoc Duncan's tests (P < 0.05). Results: No difference in hardness was encountered between deciduous and permanent teeth (P < 0.05) or modulus of elasticity (P < 0.05) before or after the wear challenges for all of the dental materials tested. Conclusions: Wear challenges against the studied dental materials did not alter the properties of permanent or deciduous teeth after the application of a 3 N load. PMID:26929700

Human immature dental pulp stem cells (hIDPSCs), their application to cell therapy and bioengineering: an analysis by systematic revision of the last decade of literature.

PubMed

de Souza, Priscilla Vianna; Alves, Fabiana Bucholdz Teixeira; Costa Ayub, Cristina Lucia Sant'Ana; de Miranda Soares, Maria Albertina; Gomes, Jose Rosa

2013-12-01

During recent years, attention has been given to the potential of therapeutic approaches using stem cells obtained from dental pulp tissue. The aim of this study, therefore, was to give an overview of the papers produced during the last 10 years that have described the use of stem cells obtained from human deciduous teeth in cell therapy or bioengineering. The PubMed database was investigated from January 2002 until July 2011 and the papers published during this period were analyzed according to criteria previously established, using the methodology of systematic review. The measurements were done using "stem cell" as the primary keyword, and "human deciduous teeth dental pulp cell" and "human exfoliated deciduous teeth" as the secondary keywords. Four hundred and seventy-five papers were found. The first screening resulted in 276 papers, from which 84 papers were selected. However, only 11 of them attained the aim proposed in our approach. There were few scientific studies related to direct therapeutic application using stem cells of human deciduous teeth and none of them had been applied to humans. However, the results indicated important and promising applications of the pulp stem-cells in cell therapy and bioengineering as demonstrated by studies in animal models of muscular dystrophy, Parkison's disease, and lupus erythematosus. Copyright © 2013 Wiley Periodicals, Inc.

Management of unerupted maxillary deciduous central incisor: a case report.

PubMed

Shakra, Karam Abu

2014-01-01

Failure of eruption of primary teeth can be considered rare, especially in maxillary anterior teeth. The problem can be either mechanical obstruction of eruption or a failure of the eruption mechanism. This case report presents failure of eruption of the maxillary right deciduous central incisor in a 4-year-old girl. The unerupted primary tooth was removed surgically. The histological finding revealed fibroma with reactive giant cells. Periodic follow-up visits were advised to monitor the developing dentition and to ensure enough space for the permanent incisor. How to cite this article: Shakra KA. Management of Unerupted Maxillary Deciduous Central Incisor: A Case Report. Int J Clin Pediatr Dent 2014;7(1):58-60.

Dental anomalies of the deciduous dentition among Indian children: a survey from Jodhpur, Rajasthan, India.

PubMed

Deolia, Shravani Govind; Chhabra, Chaya; Chhabra, Kumar Gaurav; Kalghatgi, Shrivardhan; Khandelwal, Naresh

2015-01-01

Anomalies and enamel hypoplasia of deciduous dentition are routinely encountered by dental professionals and early detection and careful management of such conditions facilitates may help in customary occlusal development. The aim of this study was to determine the prevalence of hypodontia, microdontia, double teeth, and hyperdontia of deciduous teeth among Indian children. The study group comprised 1,398 children (735 boys, 633 girls). The children were examined in department of Pedodontics and Preventive Dentistry in Jodhpur Dental College General Hospital, Jodhpur, Rajasthan, India. Clinical data were collected by single dentist according to Kreiborg criteria, which includes double teeth, hypodontia, microdontia, and supernumerary teeth. Statistical analysis of the data was performed using the descriptive analysis and chi-square test. Dental anomalies were found in 4% of children. The distribution of dental anomalies were significantly more frequent (P = 0.001) in girls (5.8%, n = 38) than in boys (2.7%, n = 18). In relation to anomaly frequencies at different ages, significant difference was found between 2 and 3 years (P = 0.001). Double teeth were the most frequently (2.3%) observed anomaly. The other anomalies followed as 0.3% supernumerary teeth, 0.6% microdontia, 0.6% hypodontia. Identification of dental anomalies at an early age is of great importance as it prevents malocclusions, functional and certain psychological problems.

Enamel thickness variation of deciduous first and second upper molars in modern humans and Neanderthals.

PubMed

Fornai, Cinzia; Benazzi, Stefano; Svoboda, Jiří; Pap, Ildikó; Harvati, Katerina; Weber, Gerhard W

2014-11-01

Enamel thickness and dental tissue proportions have been recognized as effective taxonomic discriminators between Neanderthal and modern humans teeth. However, most of the research on this topic focused on permanent teeth, and little information is available for the deciduous dentition. Moreover, although worn teeth are more frequently found than unworn teeth, published data for worn teeth are scarce and methods for the assessment of their enamel thickness need to be developed. Here, we addressed this issue by studying the 2D average enamel thickness (AET) and 2D relative enamel thickness (RET) of Neanderthal and modern humans unworn to moderately worn upper first deciduous molars (dm(1)s) and upper second deciduous molars (dm(2)s). In particular, we used 3D μCT data to investigate the mesial section for dm(1)s and both mesial and buccal sections for dm(2)s. Our results confirmed previous findings of an Neanderthal derived condition of thin enamel, and thinner enamel in dm(1)s than dm(2)s in both Neanderthal and modern humans. We demonstrated that the Neanderthal 2D RET indices are significantly lower than those of modern humans at similar wear stages in both dm(1)s and dm(2)s (p < 0.05). The discriminant analysis showed that using 2D RET from dm(1) and dm(2) sections at different wear stages up to 93% of the individuals are correctly classified. Moreover, we showed that the dm(2) buccal sections, although non-conventionally used, might have an advantage on mesial sections since they distinguish as well as mesial sections but tend to be less worn. Therefore, the 2D analysis of enamel thickness is suggested as a means for taxonomic discrimination between modern humans and Neanderthal unworn to moderately worn upper deciduous molars. Copyright © 2014 Elsevier Ltd. All rights reserved.

Prevalence and distribution of dental anomalies: a comparison between maxillary and mandibular tooth agenesis.

PubMed

Al-Abdallah, Mariam; AlHadidi, Abeer; Hammad, Mohammad; Al-Ahmad, Hazem; Saleh, Raja'

2015-11-01

The aim of this study was to compare the pattern and prevalence of associated dental anomalies between maxillary and mandibular tooth agenesis (hypodontia). A sample of 3315 dental patients, aged 8.6 to 25.4 years, was surveyed for tooth agenesis (excluding third molars): 106 subjects were diagnosed with maxillary hypodontia (group 1) and 70 with mandibular hypodontia (group 2). Both groups were examined for the following dental anomalies: retained deciduous molars, infraocclusion of deciduous molars, impaction, microdontia of maxillary lateral incisors, supernumerary teeth, transposition, transmigration, and ectopic eruption of the permanent molars. For statistical testing, the chi-square test (P <0.05) was used to compare the occurrences of these anomalies among the groups. We found that 77.5% of the patients in the mandibular hypodontia group had at least 1 dental anomaly compared with 49.5% in the maxillary hypodontia group (P <0.0001). The only dental anomaly with a significantly increased prevalence in the maxillary hypodontia group compared with the mandibular hypodontia group was microdontia of the maxillary lateral incisors (groups 1, 46.7%; group 2, 12.9%; P <0.0001). On the other hand, the prevalences of retained deciduous molars (group 1, 9.4%; group 2, 60.0%), infraoccluded deciduous molars (group 1, 0.9%; group 2, 7.1%), and impacted teeth (group 1, 22.6%; group 2, 38.6%) were significantly higher in the mandibular hypodontia group. The prevalences of supernumerary teeth, transposition, transmigration, and ectopic eruption of permanent molars were low and not significantly different between the groups. Tooth agenesis isolated to the maxilla is frequently associated with microdontia of the maxillary lateral incisors, whereas tooth agenesis isolated to the mandible is frequently associated with retained deciduous molars, infraoccluded deciduous molars, and impacted teeth. The results of this study may provide additional evidence supporting the field-specific genetic control theory for dental development in both jaws. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

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

PubMed Central

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

2011-01-01

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

Age Estimation of Infants Through Metric Analysis of Developing Anterior Deciduous Teeth.

PubMed

Viciano, Joan; De Luca, Stefano; Irurita, Javier; Alemán, Inmaculada

2018-01-01

This study provides regression equations for estimation of age of infants from the dimensions of their developing deciduous teeth. The sample comprises 97 individuals of known sex and age (62 boys, 35 girls), aged between 2 days and 1,081 days. The age-estimation equations were obtained for the sexes combined, as well as for each sex separately, thus including "sex" as an independent variable. The values of the correlations and determination coefficients obtained for each regression equation indicate good fits for most of the equations obtained. The "sex" factor was statistically significant when included as an independent variable in seven of the regression equations. However, the "sex" factor provided an advantage for age estimation in only three of the equations, compared to those that did not include "sex" as a factor. These data suggest that the ages of infants can be accurately estimated from measurements of their developing deciduous teeth. © 2017 American Academy of Forensic Sciences.

Early Pleistocene hominin deciduous teeth from the Homo antecessor Gran Dolina-TD6 bearing level (Sierra de Atapuerca, Spain).

PubMed

Bermúdez de Castro, José María; Martinón-Torres, María; Martín-Francés, Laura; Martínez de Pinillos, Marina; Modesto-Mata, Mario; García-Campos, Cecilia; Wu, Xiujie; Xing, Song; Liu, Wu

2017-07-01

During the last 13 years, the late Early Pleistocene Gran Dolina-TD6-2 level (Sierra de Atapuerca, northern Spain) has yielded an additional sample of 26 dental specimens attributed to Homo antecessor. In this report, we present a descriptive and comparative study of the six deciduous teeth. We provide external and internal morphological descriptions following classical terminology, as well as the mesiodistal and buccolingual measurements of the teeth. The internal morphology was described by means of micro-CT technique. The TD6 deciduous teeth preserve primitive features regarding the Homo clade, such as the presence of styles in lower and upper canines and developed anterior and posterior foveae in the dm 2 . However, other features related to the complexity of the crown morphology (e.g., cingulum) are not present in this sample. Furthermore, the great reduction of the talonid of the dm 1 s is also noteworthy. Despite the limited comparative evidence, the presence of a remarkably well-developed tuberculum molare in the dm 1 and dm 1 s from TD6 can be also considered a derived feature in the genus Homo. The TD6 hominins exhibit dental dimensions similar to those of other Pleistocene hominins. The dm 1 s are buccolingually elongated and the buccolingual diameter of ATD6-93 is the largest recorded so far in the Homo fossil record. This study expands the list of plesiomorphic features of H. antecessor, and provides some information on the evolutionary status of this species. However, the identification of some advanced traits evinces a step towards the derived morphology of European Pleistocene teeth. The study of the deciduous dentition confirms the mosaic pattern of H. antecessor morphology revealed in previous studies of this hominin sample. © 2017 Wiley Periodicals, Inc.

Mercury Amalgam Diffusion in Human Teeth Probed Using Femtosecond LIBS.

PubMed

Bello, Liciane Toledo; da Ana, Patricia Aparecida; Santos, Dário; Krug, Francisco José; Zezell, Denise Maria; Vieira, Nilson Dias; Samad, Ricardo Elgul

2017-04-01

In this work the diffusion of mercury and other elements from amalgam tooth restorations through the surrounding dental tissue (dentin) was evaluated using femtosecond laser-induced breakdown spectroscopy (fs-LIBS). To achieve this, seven deciduous and eight permanent extracted human molar teeth with occlusal amalgam restorations were half-sectioned and analyzed using pulses from a femtosecond laser. The measurements were performed from the amalgam restoration along the amalgam/dentin interface to the apical direction. It was possible to observe the presence of metallic elements (silver, mercury, copper and tin) emission lines, as well as dental constituent ones, providing fingerprints of each material and comparable data for checking the consistence of the results. It was also shown that the elements penetration depth values in each tooth are usually similar and consistent, for both deciduous and permanent teeth, indicating that all the metals diffuse into the dentin by the same mechanism. We propose that this diffusion mechanism is mainly through liquid dragging inside the dentin tubules. The mercury diffused further in permanent teeth than in deciduous teeth, probably due to the longer diffusion times due to the age of the restorations. It was possible to conclude that the proposed femtosecond-LIBS system can detect the presence of metals in the dental tissue, among the tooth constituent elements, and map the distribution of endogenous and exogenous chemical elements, with a spatial resolution that can be brought under 100 µm.

Morphological, chemical and structural characterisation of deciduous enamel: SEM, EDS, XRD, FTIR and XPS analysis.

PubMed

Zamudio-Ortega, C M; Contreras-Bulnes, R; Scougall-Vilchis, R J; Morales-Luckie, R A; Olea-Mejía, O F; Rodríguez-Vilchis, L E

2014-09-01

The purpose of this study was to characterise the enamel surface of sound deciduous teeth in terms of morphology, chemical composition, structure and crystalline phases. The enamel of 30 human deciduous teeth was examined by: Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), X-ray Powder Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Photoelectron Spectroscopy (XPS). Chemical differences between incisors and canines were statistically evaluated using the Mann-Whitney U test (p ≤ 0.05). Three enamel patterns were observed by SEM: 'mostly smooth with some groves', 'abundant microporosities' and 'exposed prisms'. The average Ca/P molar ratios were 1.37 and 1.03 by EDS and XPS, respectively. The crystallite size determined by XRD was 210.82 ± 16.78 Å. The mean ratio between Ca bonded to phosphate and Ca bonded to hydroxyl was approximately 10:1. The enamel of sound deciduous teeth showed two main patterns: 'mostly smooth with some groves' and 'abundant microporosities'. 'Exposed prisms' was a secondary pattern. There were slight variations among the Ca/P molar ratios found by EDS and XPS, suggesting differences in the mineral content from the enamel surface to the interior. The crystalline phases found in enamel were hydroxyapatite and carbonate apatite, with major type B than type A carbonate incorporation.

Lead levels in deciduous teeth of children in Bahrain.

PubMed

al-Mahroos, F; al-Saleh, F S

1997-06-01

To determine lead exposure among children in Bahrain, a total of 280 shed deciduous whole teeth were collected from 269 children. Teeth were analyzed for lead concentrations using atomic absorption spectrophotometry with electrothermal atomization. Children were between 5 and 15 years old. The study period extended from July 1993 to April 1994. The study showed that the overall mean tooth-lead level was 4.3 micrograms/g dry weight with a range of 0.1-60.8 micrograms/g dry weight. The cumulative frequency distribution revealed that 35% of the teeth had a lead concentration of more than 4 micrograms/g dry weight. The tooth-lead concentrations differed according to the tooth type age. The child's sex, nationality, area of residence and socio-economic status had no impact on tooth-lead level. In conclusion, lead is present in toxic concentrations in 35% of the teeth of the children studied. Urgent measures are needed to eliminate lead from gasoline, paint and other sources in the environment.

Pluripotency of Stem Cells from Human Exfoliated Deciduous Teeth for Tissue Engineering

PubMed Central

Rosa, Vinicius; Dubey, Nileshkumar; Islam, Intekhab; Min, Kyung-San; Nör, Jacques E.

2016-01-01

Stem cells from human exfoliated deciduous teeth (SHED) are highly proliferative pluripotent cells that can be retrieved from primary teeth. Although SHED are isolated from the dental pulp, their differentiation potential is not limited to odontoblasts only. In fact, SHED can differentiate into several cell types including neurons, osteoblasts, adipocytes, and endothelial cells. The high plasticity makes SHED an interesting stem cell model for research in several biomedical areas. This review will discuss key findings about the characterization and differentiation of SHED into odontoblasts, neurons, and hormone secreting cells (e.g., hepatocytes and islet-like cell aggregates). The outcomes of the studies presented here support the multipotency of SHED and their potential to be used for tissue engineering-based therapies. PMID:27313627

Fused primary first mandibular macromolar with a unique relation to its permanent successors: A rare tooth anomaly.

PubMed

Dhindsa, Abhishek; Garg, Shalini; Damle, S G; Opal, Shireen; Singh, Tavleen

2013-04-01

Dental anomalies of number and forms may occur in the primary and permanent dentition. Various terms have been used to describe dental twinning anomalies: Germination, fusion, concrescence, double teeth, conjoined teeth, twinned teeth, geminifusion, and vicinifusion. Fused tooth is a developmental anomaly that is seen more frequently in the primary than the permanent dentition. Double tooth involving deciduous anterior teeth is found mostly in the mandible. Very few cases of nonsyndromic double primary molar have been reported in the literature. The succeeding permanent tooth is often found missing congenitally in the same region. This article reports a very rare unilateral occurrence of an anomalous, primary mandibular first macromolar formed by fusion with a dysmorphic premolar like supernumerary tooth in deciduous dentition period. Instead of agenesis of succedaneous tooth, the double tooth has been succeeded by normally developing mandibular first premolar in the same region.

Sugar consumption and dental caries experience in Kenya.

PubMed

Macigo, Francis Githua; James, Regina Mutave; Ogunbodede, Eyitope; Gathece, Loice Warware

2016-06-01

There have been claims that dental caries experience and prevalence in Kenya has been increasing as a result of increased sugar consumption. A review of the literature in 1986 failed to link dental caries experience with an increase in gross national sugar consumption. Subsequently, a number of studies were conducted, necessitating further review to examine trends in dental caries experience and to relate this to changes in per capita sugar consumption. Studies conducted since 1980 for children 3-15 years of age were examined. Dental caries prevalence and experience for 3-5 years' (deciduous teeth) and 12 years' (permanent teeth) age groups were analysed. Calculation of per capita sugar consumption was performed using gross national annual sugar consumption for 1969-2009 national population census years. There was a gradual increase in per capita sugar consumption, from 35.5 g/day in 1969 to 60.8 g/day in 2009. Dental caries experience in deciduous teeth for children 3-5 years of age increased from a decayed, missing and filled teeth/decayed and filled teeth (dmft/dft) index of 1.5 in the 1980s to 2.95 in the 2000s. At 12 years of age, caries experience for permanent teeth increased from a DMFT of 0.2 to a DMFT of 0.92 over the same period. Dental caries prevalence for both deciduous and permanent teeth also increased with time. These observations suggest that dental caries prevalence and experience increased with time, in parallel to an increase in per capita sugar consumption. However, a clearer understanding can be derived from longitudinal studies, based on actual household age-specific sugar consumption and dental caries incidence. © 2016 FDI World Dental Federation.

Deciduous tooth chronology in the mandible of the domestic pig.

PubMed

Bivin, W S; McClure, R C

1976-01-01

Fetuses of known age, collected from 20 days' gestation to term, were used to characterize the chronology of deciduous tooth development within the right mandible of swine. Tooth development was first observed at 32 days' embryonic development, with the differentiation of the deciduous third molar. Bud stages for the remaining deciduous teeth differentiated within the period of 32 to 38 days of embryonic development. Although the initial histological appearance of these teeth covered a short period of time, it was apparent that each tooth continued to develop at its own rate. The deciduous second incisor and first molar reached a stage of enamel formation by the 80th and 86th day of fetal development. This is a much later stage than previously recorded for beginning enamel formation. The stages of tooth development and enamel formation for each tooth are summarized. A previous report on the distribution of the dental lamina and deciduous tooth development in the mandible of the domestic pig combined with the information presented in this report on tooth chronology provide much of the information required for future studies using the domestic pig in dental research. A fetus observed at the 74th day of development demonstrated a tooth bud for the deciduous first premolar. The development of this tooth was followed closely throughout the remainder of fetal development with the cap stage representing its most definitive form at 110 days' development. The suggested deciduous origin for this tooth could result in a reevaluation of the nomenclature for the dental formula of swine.

Bond Strength and Interfacial Morphology of Different Dentin Adhesives in Primary Teeth

PubMed Central

Vashisth, Pallavi; Mittal, Mudit; Goswami, Mousumi; Chaudhary, Seema; Dwivedi, Swati

2014-01-01

Objective: To evaluate the interfacial morphology and the bond strength produced by the three-step, two-step and single-step bonding systems in primary teeth. Materials and Methods: Occlusal surfaces of 72 extracted human deciduous teeth were ground to expose the dentin. The teeth were divided into four groups: (a) Scotchbond Multipurpose (3M, ESPE), (b) Adh Se (Vivadent), (d) OptiBond All-in-One (Kerr) and (e)Futurabond NR (VOCO, Cuxhaven, Germany). The adhesives were applied to each group following the manufacturer’s instructions. Then, teeth from each group were divided into two groups: (A) For viewing interfacial morphology (32 teeth), with 8 teeth in each group, and (B) For measurement of bond strength (40 teeth), with 10 teeth in each group. All the samples were prepared for viewing under SEM. The statistical analysis was done using SPSS version 15.0 software. Results: Observational measurement of tag length in different adhesives revealed that Scotchbond had the most widely spread values with a range from 12.20 to 89.10μm while OptiBond AIO had the narrowest range (0 to 22.50). The bond strength of Scotchbond Multipurpose was significantly higher (7.4744±1.88763) (p<0.001) as compared to Futurabond NR (3.8070±1.61345), Adhe SE (4.4478 ± 1.3820) and OptiBond-all-in-one (4.4856±1.07925). Conclusion: The three-step bonding system showed better results as compared to simplified studied bonding systems PMID:24910694

Ectopic Hard Tissue Formation by Odonto/Osteogenically In Vitro Differentiated Human Deciduous Teeth Pulp Stem Cells.

PubMed

Kim, Seunghye; Song, Je Seon; Jeon, Mijeong; Shin, Dong Min; Kim, Seong-Oh; Lee, Jae Ho

2015-07-01

There have been many attempts to use the pulp tissue from human deciduous teeth for dentin or bone regeneration. The objective of this study was to determine the effects of odonto/osteogenic in vitro differentiation of deciduous teeth pulp stem cells (DTSCs) on their in vivo hard tissue-forming potential. DTSCs were isolated from extracted deciduous teeth using the outgrowth method. These cells were exposed to odonto/osteogenic stimuli for 4 and 8 days (Day 4 and Day 8 groups, respectively), while cells in the control group were cultured in normal medium. The in vitro differentiated DTSCs and the control DTSCs were transplanted subcutaneously into immunocompromised mice with macroporous biphasic calcium phosphate and sacrificed at 8 weeks post-implantation. The effect of odonto/osteogenic in vitro differentiation was evaluated using alkaline phosphatase (ALP) staining and quantitative reverse transcription polymerase chain reaction (RT-PCR). The in vivo effect was evaluated by qualitative RT-PCR, assessment of ALP activity, histologic analysis, and immunohistochemical staining. The amount of hard tissue was greater in Day 4 group than Day 8 group (p = 0.014). However, Day 8 group generated lamellar bone-like structure, which was immunonegative to anti-human dentin sialoprotein with significantly low expression level of DSPP compared with the control group (p = 0.008). This study demonstrates that odonto/osteogenic in vitro differentiation of DTSCs enhances the formation of bone-like tissue, instead of dentin-like tissue, when transplanted subcutaneously using MBCP as a carrier. The odonto/osteogenic in vitro differentiation of DTSCs may be an effective modification that enhances in vivo bone formation by DTSCs.

Effect of Polyhydroxybutyrate/Chitosan/Bioglass nanofiber scaffold on proliferation and differentiation of stem cells from human exfoliated deciduous teeth into odontoblast-like cells.

PubMed

Khoroushi, Maryam; Foroughi, Mohammad Reza; Karbasi, Saeed; Hashemibeni, Batool; Khademi, Abbas Ali

2018-08-01

Scaffolds and their characteristics play a central role in tissue engineering. The purpose of this study was to determine the effects of Polyhydroxybutyrate (PHB)/Chitosan/nano-bioglass (nBG) nanofiber scaffold made using the electrospinning method, on the proliferation and differentiation of stem cells obtained from human exfoliated deciduous teeth into odontoblast-like cells. In this experimental study, the pulps of the molten deciduous teeth were isolated, thereafter, the stem cells from human exfoliated deciduous teeth (SHED) were extracted and then the 3-(4,5-dimethylthiazolyl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to determine the cell viability percentage. The expression of some stem cell genes was studied by flowcytometry. These cells were then subjected to odontoblast by using the bone morphogenetic proteins-2 (BMP2) growth factor in the differentiation medium and for the expression of their specific genes. Primers of collagen type-I, dentin sialophosphoprotein (DSPP) and alkaline phosphatase (ALP) were used and the percentage of differentiation to odontoblast cells in induction scaffolds was investigated using real-time PCR and immunohistochemistry methods. The results revealed a 6-fold increase in the expression of DSPP genes and collagen type-I, and a 2-fold increase in the expression of ALP in scaffold with BMP2 group compared to the scaffold as control group which according to the immunohistochemical test results, showed the extracted SHED to have been differentiated into dentin odontoblast-like cells. As a result, this scaffold can be used as a suitable substrate to apply in dentin tissue engineering. Copyright © 2018. Published by Elsevier B.V.

Comparative Gene Expression Analysis of the Human Periodontal Ligament in Deciduous and Permanent Teeth

PubMed Central

Kim, Seong-Oh; Jeon, Mijeong; Choi, Byung-Jai; Jung, Han-Sung; Moon, Seok Jun; Park, Wonse; Choi, Hyung-Jun

2013-01-01

There are histological and functional differences between human deciduous and permanent periodontal ligament (PDL) tissues. The aim of this study was to determine the differences between these two types of tissue at the molecular level by comparing their gene expression patterns. PDL samples were obtained from permanent premolars (n = 38) and anterior deciduous teeth (n = 31) extracted from 40 healthy persons. Comparative cDNA microarray analysis revealed several differences in gene expression between the deciduous and permanent PDL tissues. These findings were verified by qRT-PCR (quantitative reverse-transcription–polymerase chain reaction) analysis, and the areas where genes are expressed were revealed by immunohistochemical staining. The expressions of 21 genes were up-regulated in deciduous relative to PDL tissues, and those of 30 genes were up-regulated in permanent relative to deciduous PDL tissues. The genes that were up-regulated in deciduous PDL tissues were those involved in the formation of the extracellular matrix (LAMC2, LAMB3, and COMP), tissue development (IGF2BP, MAB21L2, and PAX3), and inflammatory or immune reactions leading to tissue degradation (IL1A, CCL21, and CCL18). The up-regulated genes in permanent PDL tissues were related to tissue degradation (IL6 and ADAMTS18), myocontraction (PDE3B, CASQ2, and MYH10), and neurological responses (FOS, NCAM2, SYT1, SLC22A3, DOCK3, LRRTM1, LRRTM3, PRSS12, and ARPP21). The analysis of differential gene expressions between deciduous and permanent PDL tissues aids our understanding of histological and functional differences between them at the molecular level. PMID:23593441

Comparative gene expression analysis of the human periodontal ligament in deciduous and permanent teeth.

PubMed

Song, Je Seon; Hwang, Dong Hwan; Kim, Seong-Oh; Jeon, Mijeong; Choi, Byung-Jai; Jung, Han-Sung; Moon, Seok Jun; Park, Wonse; Choi, Hyung-Jun

2013-01-01

There are histological and functional differences between human deciduous and permanent periodontal ligament (PDL) tissues. The aim of this study was to determine the differences between these two types of tissue at the molecular level by comparing their gene expression patterns. PDL samples were obtained from permanent premolars (n = 38) and anterior deciduous teeth (n = 31) extracted from 40 healthy persons. Comparative cDNA microarray analysis revealed several differences in gene expression between the deciduous and permanent PDL tissues. These findings were verified by qRT-PCR (quantitative reverse-transcription-polymerase chain reaction) analysis, and the areas where genes are expressed were revealed by immunohistochemical staining. The expressions of 21 genes were up-regulated in deciduous relative to PDL tissues, and those of 30 genes were up-regulated in permanent relative to deciduous PDL tissues. The genes that were up-regulated in deciduous PDL tissues were those involved in the formation of the extracellular matrix (LAMC2, LAMB3, and COMP), tissue development (IGF2BP, MAB21L2, and PAX3), and inflammatory or immune reactions leading to tissue degradation (IL1A, CCL21, and CCL18). The up-regulated genes in permanent PDL tissues were related to tissue degradation (IL6 and ADAMTS18), myocontraction (PDE3B, CASQ2, and MYH10), and neurological responses (FOS, NCAM2, SYT1, SLC22A3, DOCK3, LRRTM1, LRRTM3, PRSS12, and ARPP21). The analysis of differential gene expressions between deciduous and permanent PDL tissues aids our understanding of histological and functional differences between them at the molecular level.

Interrelationships Between Morphometric, Densitometric, and Mechanical Properties of Teeth in 5-Month-Old Polish Merino Sheep.

PubMed

Tatara, Marcin R; Szabelska, Anna; Krupski, Witold; Tymczyna, Barbara; Łuszczewska-Sierakowska, Iwona; Bieniaś, Jarosław; Ostapiuk, Monika

2018-06-01

Interrelationships between morphological, densitometric, and mechanical properties of deciduous mandibular teeth (incisors, canine, second premolar) were investigated. To perform morphometric, densitometric, and mechanical analyses, teeth were obtained from 5-month-old sheep. Measurements of mean volumetric tooth mineral density and total tooth volume were performed using quantitative computed tomography. Microcomputed tomography was used to measure total enamel volume, volumetric enamel mineral density, total dentin volume, and volumetric dentin mineral density. Maximum elastic strength and ultimate force of teeth were determined using 3-point bending and compression tests. Pearson correlation coefficients were determined between all investigated variables. Mutual dependence was observed between morphological and mechanical properties of the investigated teeth. The highest number of positive correlations of the investigated parameters was stated in first incisor indicating its superior predictive value of tooth quality and masticatory organ function in sheep. Positive correlations of the volumetric dentin mineral density in second premolar with final body weight may indicate predictive value of this parameter in relation with growth rate in sheep. Evaluation of deciduous tooth properties may prove helpful for breeding selection and further reproduction of sheep possessing favorable traits of teeth and better masticatory organ function, leading to improved performance and economic efficiency of the flock.

Dental fluorosis in children in areas with fluoride-polluted air, high-fluoride water, and low-fluoride water as well as low-fluoride air: a study of deciduous and permanent teeth in the Shaanxi province, China.

PubMed

Ruan, Jian Ping; Bårdsen, Asgeir; Astrøm, Anne Nordrehaug; Huang, Rui Zhe; Wang, Zhi Lun; Bjorvatn, Kjell

2007-04-01

The aim of the study was to assess dental fluorosis (DF) in the deciduous and permanent teeth of children in areas with high-F coal (area A) and high-F water (area C) compared to children from area B, with low-F water and coal. 596 children were examined. DF was assessed by TF-score. F-content of indoor air, drinking water, coal, tea, rice, and maize was analyzed. F-content of air and coal ranged from 3.2 microg/m(3) and 25.8 mg/kg (area B), 3.8 microg/m(3) and 36.3 mg/kg (area C) to 56.8 microg/m(3) and 713.1 mg/kg (area A). Likewise, mean F-content of water ranged from approximately 0.50 mg/l (areas A and B) to 3.64 mg/l (area C). F-content of tea leaves was similar in all three areas. Maize and rice contained <5 mg F/kg. Prevalence of primary teeth with DF was 49.1%, 2.0%, and 66.8% in areas A, B, and C, respectively. Similarly, DF was found in 96.7% (area A), 19.6% (area B), and 94.4% (area C) of the permanent teeth. Severe fluorosis (TF > or = 5) was found in area A (47.0%) and area C (36.1%) (p<0.01). Early erupting teeth had slightly higher mean TF-scores in area A than in area C. DF was prevalent in both dentitions in areas A and C. Similarity in percentages of DF may indicate that indoor air with approximately 60 microg F/m(3) and drinking water with 3.6 mg F/L are similarly toxic to developing permanent teeth. The percentage of deciduous teeth with DF was significantly lower in area A compared to area C. Where low-F coal and low-F water were used (area B), approximately 20% of permanent teeth had DF, indicating a relatively low tolerance to fluoride in Chinese children brought up under the present living conditions.

Transplantation of stem cells from human exfoliated deciduous teeth for bone regeneration in the dog mandibular defect

PubMed Central

Behnia, Ali; Haghighat, Abbas; Talebi, Ardeshir; Nourbakhsh, Nosrat; Heidari, Fariba

2014-01-01

AIM: To investigate the effect of stem cells from human exfoliated deciduous teeth (SHED) transplanted for bone regeneration in the dog mandibular defect. METHODS: In this prospective comparative study, SHEDs had been isolated 5 years ago from human exfoliated deciduous teeth. The undifferentiated stem cells were seeded into mandibular bone through-and-through defects of 4 dogs. Similar defects in control group were filled with cell-free collagen scaffold. After 12 wk, biopsies were taken and morphometric analysis was performed. The percentage of new bone formation and foreign body reaction were measured in each case. The data were subject to statistical analysis using the Mann-Whitney U and Kruskalwalis statistical tests. Differences at P < 0.05 was considered as significant level. RESULTS: There were no significant differences between control and SHED-seeded groups in connective tissue (P = 0.248), woven bone (P = 0.248) and compact bone (P = 0.082). There were not any side effects in transplanted SHED group such as teratoma or malignancy and abnormalities in this period. CONCLUSION: SHEDs which had been isolated and characterized 5 years ago and stored with cryopreservation banking were capable of proliferation and osteogenesis after 5 years, and no immune response was observed after three months of seeded SHEDs. PMID:25258673

Effectiveness of Morinda citrifolia juice as an intracanal irrigant in deciduous molars: An in vivo study

PubMed Central

Chandwani, Manisha; Mittal, Rakesh; Chandak, Shweta; Pimpale, Jitesh

2017-01-01

Background: The purpose of this study was to evaluate the microbial reduction in deciduous molars using Morinda citrifolia juice (MCJ) as irrigating solution. Materials and Methods: This was a randomized comparative study including 60 deciduous molars chosen among the patients belonging to the age group of 6–9 years based on the inclusion or exclusion criteria. The selected teeth were divided randomly into two groups based on irrigation solution used, that was, Group I (1% NaOCl) and Group II (MCJ). The microbial samples were collected both pre- and post-irrigation and were transferred for microbial assay. Paired t-test was used for intragroup analysis of pre- and post-operative mean reduction of bacterial colony forming unit (CFU)/ml, whereas Independent t-test was used to assess the intergroup, pre- and post-operative mean reduction of bacterial CFU/ml. Results: In the intragroup comparison, both of the groups showed statistically significant (P < 0.001) reduction in the mean CFU/ml; however, it did not show statistically significant reduction when intergroup comparison was carried out between the two groups. Both the study materials had clinically revealed decrease in the microbial count postirrigation. Conclusion: Both the irrigants, 1% NaOCl and MCJ, were significantly effective in the reduction of mean CFUs/ml postoperatively. The results of this study have confirmed the antibacterial effectiveness of MCJ in the root canals of deciduous teeth. Considering the low toxicity and antibacterial effectiveness of MCJ, it can be advocated as a root canal irrigant in endodontic treatment of primary teeth. PMID:28928778

The relationships between the arrangement of teeth, root resorption, and dental maturity in bovine mandibular incisors

PubMed Central

An, Jin-kyu; Ono, Takashi

2017-01-01

Objective The objective of this study is to investigate the eruption pattern and root resorption of the bovine anterior dentition in relation to growth-related parameters based on dental maturity. Methods A cross-sectional study was conducted on 110 bovine anterior mandibles by using standard radiography, cone-beam computed tomography (CBCT), and actual measurements. We determined the relationships between the stages of dental maturity by using a modification of Demirjian's method and various growth-related parameters, such as the activity of the root-resorbing tissue and mobility of the deciduous teeth. The correlation of growth-related parameters with interdental spacing and distal unusual root resorption (DRR) of the deciduous fourth incisor was assessed. The cause of mesial unusual root resorption (MRR) of the deciduous fourth incisor was determined on the basis of the arrangement of the permanent third incisor. Results An independent t-test and chi-square test indicated significant differences in growth-related parameters associated with dental arch length discrepancy and factors related to the shedding of deciduous teeth between the low and high dental maturity groups. The samples with interdental spacing and DRR showed a larger sum of mesiodistal permanent crown widths and higher dental maturity than did the respective controls. Samples with MRR tended to show a lingually rotated distal tip of the adjacent tooth crown. Conclusions Dental maturity has relevance to the interdental spaces and unusual root resorption of mixed dentition. The position of the adjacent tooth crown on CBCT may be correlated with the occurrence of unusual root resorption of the incisor. PMID:29090124

Insufficient Sleep and Incidence of Dental Caries in Deciduous Teeth among Children in Japan: A Population-Based Cohort Study.

PubMed

Chen, Hongyan; Tanaka, Shiro; Arai, Korenori; Yoshida, Satomi; Kawakami, Koji

2018-04-27

To examine whether late bedtime and short nighttime sleep duration at age 18 months are associated with risk of caries in deciduous teeth. Population-based cohort study using health check-up data of 71 069 children born in Kobe City, Japan, who were free of caries at age 18 months and had information on sleep variables at age 18 months and records of dental examinations at age 3 years. Sleep variables were assessed by standardized parent-reported questionnaires, and the incidence of caries in deciduous teeth was defined as the occurrence of at least 1 decayed, missing, or filled tooth assessed by qualified dentists without radiographs. Logistic regression was used to estimate the effects of late bedtime and short sleep duration on dental caries with adjustment for clinical and lifestyle characteristics. Overall, 11 343 (16.0%) cases of caries were observed at age 3 years. aORs for children with late or irregular bedtimes compared with those with bedtimes before 21:00 were 1.26 (95% CI 1.19-1.33), 1.48 (1.38-1.58), 1.74 (1.58-1.92), 1.90 (1.58-2.29), and 1.66 (1.53-1.81) for bedtimes at 21:00, 22:00, 23:00, 0:00, and irregular bedtime, respectively. aORs for children with short or irregular sleep duration compared with those with sleep duration of ≥11 hours were 1.30 (95% CI 1.15-1.47), 1.16 (1.09-1.24), 1.11 (1.05-1.18), and 1.35 (1.25-1.46) for sleep duration of ≤ 8, 9, 10 hours, and irregular sleep duration, respectively. In this exploratory study, late bedtime and short sleep duration were both consistently associated with increased risk of caries in deciduous teeth. Copyright © 2018 Elsevier Inc. All rights reserved.

Association between Low blood lead levels and increased risk of dental caries in children: a cross-sectional study.

PubMed

Kim, Young-Suk; Ha, Mina; Kwon, Ho-Jang; Kim, Hae-Young; Choi, Youn-Hee

2017-01-13

The objective of this study was to examine the association between low blood lead levels of <5 μg/dL and the development of dental caries among children. The Children's Health and Environment Research (CHEER) group recruited a cohort of 7,059 school-aged children from six Korean cities. The final study populations in the permanent and deciduous teeth groups were 1,564 and 1,241 children, respectively, after excluding 4 children with blood lead levels of >5 μg/dL. Compared with the children who did not have dental caries, the risk of having dental caries according to blood lead level was estimated by using the zero-inflated negative binomial model. The geometric mean (geometric standard deviation, maximum) blood lead level was 1.53 μg/dL (1.57, 4.89 μg/dL), and 74.4% of children had a level of <2 μg/dL. Blood lead level was significantly higher in the children with than in those without deciduous dental caries (1.59 vs. 1.51 μg/dL), similarly with permanent dental caries (1.65 vs. 1.51 μg/dL). After adjustment for covariates, deciduous teeth surfaces that were decayed and filled increased significantly with increasing blood lead levels in a dose-dependent manner (prevalence ratio, 1.14; 95% confidence interval: 1.02-1.27). However, the risk of having dental caries in permanent teeth was not linearly associated with the increase in blood lead level. In the sum of decayed and filled surfaces, we found a significant increase in risk of dental caries of the deciduous teeth with an increase in blood lead levels (<5 μg/dL) but found no statistical significance in the association with decayed and filled surfaces of caries separately.

Varanoid Tooth Eruption and Implantation Modes in a Late Cretaceous Mosasaur.

PubMed

Liu, Min; Reed, David A; Cecchini, Giancarlo M; Lu, Xuanyu; Ganjawalla, Karan; Gonzales, Carol S; Monahan, Richard; Luan, Xianghong; Diekwisch, Thomas G H

2016-01-01

Erupting teeth are some of the oldest witnesses of developmental processes in the vertebrate fossil record and provide an important resource for vertebrate cladistics. Here, we have examined a mosasaur jaw fragment from central Texas using ultrathin ground section histology and 3D tomographic imaging to assess features critical for the cladistic placement of mosasaurs among varanoids vs. snakes: (i) the orientation of replacement teeth compared to the major tooth axis, (ii) the occurrence of resorption pits, and (iii) the mode of tooth implantation/attachment to the tooth bearing element (TBE). The replacement tooth studied here developed in an inclined position slightly distal of the deciduous parent tooth, similar to another varanoid squamate, the Gila monster Heloderma suspectum. Ground sections and tomographs also demonstrated that the replacement tooth attachment apparatus was entirely intact and that there was no evidence of mechanical deformation. Sections and tomographs further illustrated that the replacement tooth was located within a bony crypt and the inclination of the crypt matched the inclination of the replacement tooth. These preparations also revealed the presence of a resorption pit within the boundaries of the deciduous tooth that surrounded the developing replacement tooth. This finding suggests that developing mosasaur teeth developed within the walls of resorption pits similar to varanoid tooth germs and unlike developing snake teeth which are surrounded by fibrous connective tissue integuments. Finally, mosasaurs featured pseudo-thecodont tooth implantation with teeth anchored within a socket of mineralized tissue by means of a mineralized periodontal ligament. Together, these data indicate that the moderate inclination of the erupting mosasaur tooth studied here is neither a result of postmortem displacement nor a character representative of snakes, but rather a shared character between Mosasaurs and other varanoids such as Heloderma. In conjunction with the presence of resorption pits and the evidence for pseudothecodont tooth implantation, the tooth eruption and implantation characters described in the present study either place mosasaurs among the varanoids or suggest convergent evolution mechanisms between both clades, with mosasaurs evolving somewhat independently from a common varanoid ancestor.

Varanoid Tooth Eruption and Implantation Modes in a Late Cretaceous Mosasaur

PubMed Central

Liu, Min; Reed, David A.; Cecchini, Giancarlo M.; Lu, Xuanyu; Ganjawalla, Karan; Gonzales, Carol S.; Monahan, Richard; Luan, Xianghong

2016-01-01

Erupting teeth are some of the oldest witnesses of developmental processes in the vertebrate fossil record and provide an important resource for vertebrate cladistics. Here, we have examined a mosasaur jaw fragment from central Texas using ultrathin ground section histology and 3D tomographic imaging to assess features critical for the cladistic placement of mosasaurs among varanoids vs. snakes: (i) the orientation of replacement teeth compared to the major tooth axis, (ii) the occurrence of resorption pits, and (iii) the mode of tooth implantation/attachment to the tooth bearing element (TBE). The replacement tooth studied here developed in an inclined position slightly distal of the deciduous parent tooth, similar to another varanoid squamate, the Gila monster Heloderma suspectum. Ground sections and tomographs also demonstrated that the replacement tooth attachment apparatus was entirely intact and that there was no evidence of mechanical deformation. Sections and tomographs further illustrated that the replacement tooth was located within a bony crypt and the inclination of the crypt matched the inclination of the replacement tooth. These preparations also revealed the presence of a resorption pit within the boundaries of the deciduous tooth that surrounded the developing replacement tooth. This finding suggests that developing mosasaur teeth developed within the walls of resorption pits similar to varanoid tooth germs and unlike developing snake teeth which are surrounded by fibrous connective tissue integuments. Finally, mosasaurs featured pseudo-thecodont tooth implantation with teeth anchored within a socket of mineralized tissue by means of a mineralized periodontal ligament. Together, these data indicate that the moderate inclination of the erupting mosasaur tooth studied here is neither a result of postmortem displacement nor a character representative of snakes, but rather a shared character between Mosasaurs and other varanoids such as Heloderma. In conjunction with the presence of resorption pits and the evidence for pseudothecodont tooth implantation, the tooth eruption and implantation characters described in the present study either place mosasaurs among the varanoids or suggest convergent evolution mechanisms between both clades, with mosasaurs evolving somewhat independently from a common varanoid ancestor. PMID:27242535

Cytotoxicity assessment of polyhydroxybutyrate/chitosan/nano- bioglass nanofiber scaffolds by stem cells from human exfoliated deciduous teeth stem cells from dental pulp of exfoliated deciduous tooth

PubMed Central

Hashemi-Beni, Batool; Khoroushi, Maryam; Foroughi, Mohammad Reza; Karbasi, Saeed; Khademi, Abbas Ali

2018-01-01

Background: The aim of this study was to compare the cytotoxicity and the biocompatibility of three different nanofibers scaffolds after seeding of stem cells harvested from human deciduous dental pulp. Given the importance of scaffold and its features in tissue engineering, this study demonstrated the construction of polyhydroxybutyrate (PHB)/chitosan/nano-bioglass (nBG) nanocomposite scaffold using electrospinning method. Materials and Methods: This experimental study was conducted on normal exfoliated deciduous incisors obtained from 6-year-old to 11-year-old healthy children. The dental pulp was extracted from primary incisor teeth which are falling aseptically. After digesting the tissue with 4 mg/ml of type I collagenase, the cells were cultured in medium solution. Identification of stem cells from human exfoliated deciduous teeth was performed by flowcytometry using CD19, CD14, CD146, and CD90 markers. Then, 1 × 104 stem cells were seeded on the scaffold with a diameter of 10 mm × 0.3 mm. Cell viability was evaluated on days 3, 5, and 7 through methyl thiazol tetrazolium techniques (P < 0.05) on different groups that they are groups included (1) PHB scaffold (G1), (2) PHB/chitosan scaffold (G2), (3) the optimal PHB/chitosan/nBG scaffold (G3), (4) mineral trioxide aggregate (MTA), and (5) the G3 + MTA scaffold (G3 + MTA). Data were analyzed with two-way ANOVA at significance level of P < 0.05. Results: The results indicated that the PHB/chitosan/nBG scaffold and PHB/chitosan/nBG scaffold + MTA groups showed significant difference compared with the PHB/chitosan scaffold and PHB scaffold groups on the 7th day (P < 0.05). Conclusion: Thus, it can be concluded that the scaffold with nBG nanoparticles is more biocompatible than the other scaffolds and can be considered as a suitable scaffold for growth and proliferation of stem cells. PMID:29576778

Cytotoxicity assessment of polyhydroxybutyrate/chitosan/nano- bioglass nanofiber scaffolds by stem cells from human exfoliated deciduous teeth stem cells from dental pulp of exfoliated deciduous tooth.

PubMed

Hashemi-Beni, Batool; Khoroushi, Maryam; Foroughi, Mohammad Reza; Karbasi, Saeed; Khademi, Abbas Ali

2018-01-01

The aim of this study was to compare the cytotoxicity and the biocompatibility of three different nanofibers scaffolds after seeding of stem cells harvested from human deciduous dental pulp. Given the importance of scaffold and its features in tissue engineering, this study demonstrated the construction of polyhydroxybutyrate (PHB)/chitosan/nano-bioglass (nBG) nanocomposite scaffold using electrospinning method. This experimental study was conducted on normal exfoliated deciduous incisors obtained from 6-year-old to 11-year-old healthy children. The dental pulp was extracted from primary incisor teeth which are falling aseptically. After digesting the tissue with 4 mg/ml of type I collagenase, the cells were cultured in medium solution. Identification of stem cells from human exfoliated deciduous teeth was performed by flowcytometry using CD19, CD14, CD146, and CD90 markers. Then, 1 × 10 4 stem cells were seeded on the scaffold with a diameter of 10 mm × 0.3 mm. Cell viability was evaluated on days 3, 5, and 7 through methyl thiazol tetrazolium techniques ( P < 0.05) on different groups that they are groups included (1) PHB scaffold (G1), (2) PHB/chitosan scaffold (G2), (3) the optimal PHB/chitosan/nBG scaffold (G3), (4) mineral trioxide aggregate (MTA), and (5) the G3 + MTA scaffold (G3 + MTA). Data were analyzed with two-way ANOVA at significance level of P < 0.05. The results indicated that the PHB/chitosan/nBG scaffold and PHB/chitosan/nBG scaffold + MTA groups showed significant difference compared with the PHB/chitosan scaffold and PHB scaffold groups on the 7 th day ( P < 0.05). Thus, it can be concluded that the scaffold with nBG nanoparticles is more biocompatible than the other scaffolds and can be considered as a suitable scaffold for growth and proliferation of stem cells.

BIOLOGICAL INDICATOR OF SUMMATIONAL EXPOSURES TO LEAD. TOOTH LEAD IN CHILDREN LIVING IN CLEVELAND AND ITS SUBURBS

EPA Science Inventory

An epidemiologic study of the distribution of lead absorption in the Cleveland Metropolitan Area was carried out by analyzing the lead content of shed or extracted deciduous teeth of 11,241 children. Mean amounts of lead in teeth of children living in some suburbs were as high as...

An evaluation of microleakage of various glass ionomer based restorative materials in deciduous and permanent teeth: An in vitro study

PubMed Central

Singla, Teena; Pandit, I.K.; Srivastava, Nikhil; Gugnani, Neeraj; Gupta, Monika

2011-01-01

Aim To evaluate the microleakage of recently available glass ionomer based restorative materials (GC Fuji IX GP, GC Fuji VII, and Dyract) and compare their microleakage with the previously existing glass ionomer restorative materials (GC Fuji II LC) in primary and permanent teeth. Method One hundred and fifty (75 + 75) non-carious deciduous and permanent teeth were restored with glass ionomer based restorative materials after making class I cavities. Samples were subjected to thermocycling after storing in distilled water for 24 h. Two coats of nail polish were applied 1 mm short of restorative margins and samples sectioned buccolingually after storing in methylene blue dye for 24 h. Microleakage was assessed using stereomicroscope. Result Significant differences (P < 0.05) were found when inter group comparisons were done. Except when GC Fuji VII (Group III) was compared with GC Fuji II LC (Group II) and Dyract (Group IV), non-significant differences (P > 0.05) were observed. It was found that there was no statistically significant difference when the means of microleakage of primary teeth were compared with those of permanent teeth. Conclusions GC Fuji IX GP showed maximum microleakage and GC Fuji VII showed least microleakage. PMID:23960526

Dental and craniofacial findings in eight miniature schnauzer dogs affected by myotonia congenita: preliminary results.

PubMed

Gracis, M; Keith, D; Vite, C H

2000-09-01

Myotonia is a clinical sign characterized by the delay of skeletal muscle relaxation following the cessation of a voluntary activity or the termination of an electrical or mechanical stimulus. Recently, Miniature Schnauzers with myotonia congenita associated with defective chloride ion conductance across the skeletal muscle membrane were identified. Congenital myotonia in these dogs appears to follow an autosomal recessive mode of inheritance. Craniofacial and dental findings of eight Miniature Schnauzer dogs with myotonia congenita are described in the present paper. These findings include: delayed dental eruption of both deciduous and permanent dentition: persistent deciduous dentition; unerupted or partially erupted permanent teeth: crowding and rotation of premolar and or incisor teeth: missing teeth: increased interproximal space between the maxillary fourth premolar and first molar teeth: decreased interproximal space between the maxillary canine and lateral incisor teeth: inability to fully close the mouth due to malocclusion: distoclusion: and, decreased mandibular range of motion. A long narrow skull with a flattened zygomatic arch and greater mandibular body curvature were also consistent findings in the affected dogs. The small number of dogs studied prevents conclusive statements about the origin of these abnormalities, however it is interesting that only 1 of 45 unaffected Miniature Schnauzer dogs showed similar traits.

Live Helicobacter pylori in the root canal of endodontic-infected deciduous teeth.

PubMed

Hirsch, Christian; Tegtmeyer, Nicole; Rohde, Manfred; Rowland, Marion; Oyarzabal, Omar A; Backert, Steffen

2012-08-01

Many polymerase chain reaction (PCR)-based studies have shown that Helicobacter pylori DNA is prevalent in the oral cavity, but reports on the isolation of live bacteria are extremely rare. Thus, it is still unclear whether H. pylori can indeed survive in the oral environment. Here we used electron microscopy, selective growth techniques, urease assays, 16S rRNA PCR, and western blotting to investigate the possible presence of live H. pylori in 10 root canal and corresponding plaque samples of endodontic-infected deciduous teeth in three children. Although H. pylori DNA was verifiable by PCR in several plaque and root canal samples, bacterial colonies could only be grown from two root canals, but not from plaque. These colonies were unequivocally identified as H. pylori by microscopic, genetic, and biochemical approaches. Our findings show that root canals of endodontic-infected teeth may be a reservoir for live H. pylori that could serve as a potential source for transmission.

An unexpected rise in strontium-90 in US deciduous teeth in the 1990s.

PubMed

Mangano, Joseph J; Gould, Jay M; Sternglass, Ernest J; Sherman, Janette D; McDonnell, William

2003-12-30

For several decades, the United States has been without an ongoing program measuring levels of fission products in the body. Strontium-90 (Sr-90) concentrations in 2089 deciduous (baby) teeth, mostly from persons living near nuclear power reactors, reveal that average levels rose 48.5% for persons born in the late 1990s compared to those born in the late 1980s. This trend represents the first sustained increase since the early 1960s, before atmospheric weapons tests were banned. The trend was consistent for each of the five states for which at least 130 teeth are available. The highest averages were found in southeastern Pennsylvania, and the lowest in California (San Francisco and Sacramento), neither of which is near an operating nuclear reactor. In each state studied, the average Sr-90 concentration is highest in counties situated closest to nuclear reactors. It is likely that, 40 years after large-scale atmospheric atomic bomb tests ended, much of the current in-body radioactivity represents nuclear reactor emissions.

[Constant fluoridation of drinking water and the incidence of dental caries in children and juveniles (author's transl)].

PubMed

Künzel, W

1980-01-01

The regular examination of 20,000 children and juveniles aged 6 to 15 (permanent teeth) and some 12.500 three- to eight-year-olds (deciduous teeth) has shown that the incidence of dental caries (DMF/T and df/t indices) is directly dependent upon the constant fluoridation of drinking water (1.0 +/- 0.1 ppm F). The reduction in dental caries observed on both deciduous and permanent teeth as a result of twelve years of fluoridation of drinking water, which was started in Karl-Marx-Stadt in 1959, was followed, because of the necessity to temporarily discontinue the addition of fluorine salts to the drinking water, by a slight increase in caries which could be checked through refluorination. After eighteen years of fluoridation of drinking water, the situation can again be considered to be in equilibrium. The need for proper fluoridation and regular control thereof through analyzing the fluorine content of drinking water is pointed out.

Clinical Success of Fiber-reinforced Composite Resin as a Space Maintainer.

PubMed

Kirzioğlu, Zuhal; Çiftçi, Z Zahit; Yetiş, Ceylan Ç

2017-03-01

The early loss of deciduous molars is a frequently encountered problem in dentistry. Various space maintainer designs were developed to prevent the loss of the space. The aim of this study was to evaluate long-term clinical performance and survival rates of fiber-reinforced composite resin (FRCR) as a space maintainer clinically. This study was designed on 44 children who had early missed deciduous molars. Space maintainers were prepared on plaster models of patients and fixed directly to the adjacent teeth. Survival rate and whether it causes any damage to adjacent teeth were examined clinically and radio-graphically for 24 months or until failure. Kaplan-Meier survival analysis was used for the statistical analyses. Overall, 16.2% of space maintainers were dislodged and accepted to be failed at the end of 12 months. At the 24-month control, 52.2% success was stated with the FRCR space maintainer and because of permanent tooth eruption, 31.8% of space maintainer were taken out. The mean duration of space maintainers was measured to be 14.8 ± 3.48 months. There was no statistical significance between survival time and gender, tooth number, localization, and measured space (p > 0.05). After all 24 months follow-up, as well as esthetic properties of FRCR space maintainer, their applicability in a single seance and strength against the forces are determined as the advantages of the technique. The FRCR space maintainers can be thought of as alternatives to metal space maintainers.

[Orthodontic effects of tooth injury to the permanent and temporary incisors of children and the adolescent [corrected].

PubMed

Bassigny, F

1990-01-01

Traumatisms on the deciduous upper incisors could induce orthodontic indirect consequences on the permanent germ, dependent on his growth level and his malleability, dependent on connection between the root of deciduous incisor and the crown of permanent germ and according to the type of traumatism. According to those various data, it should be observed on the permanent incisor: germination of two germs, multiple odontoma, crown dilaceration, severe tipping of the crown with facial angulation, retention of the permanent germ with lack of root resorption of the deciduous teeth or simple cross-bite, without speaking of enamel defect.

"Cariogenic potential of homemade weaning diet v/s commercial formula feeds" an in-vitro study.

PubMed

Bhat, S; Madan, I

2002-12-01

The universal phenomenon of introducing weaning diet to the growing child sets its onset by the age of 4-6 months. This preliminary diet of the child governs his or her dental health in the long run. The main objective of this study is to investigate the histopathological and clinical invasion of deciduous teeth exposed to both the homemade weaning diet and commercial formula feeds. The study also aims at motivating the consumption of the most appropriate diet for the weaning baby. Extracted deciduous teeth were incubated with the test solutions of homemade diet and commercial formula feeds for the period of 6 weeks. Fewer carious invasion both clinically and histopathologically were seen in homemade feeds. Thus, homemade diet can be a strong candidate for the status of 'THE IDEAL WEANING FOOD'.

Effect of a cryopreservation protocol on the proliferation of stem cells from human exfoliated deciduous teeth.

PubMed

Ginani, Fernanda; Soares, Diego Moura; Rabêlo, Luciana Maria; Rocha, Hugo Alexandre Oliveira; de Souza, Lélia Batista; Barboza, Carlos Augusto Galvão

2016-11-01

The aim of the present study was to evaluate the influence of a cryopreservation protocol on the proliferation and viability of stem cells from human exfoliated deciduous teeth (SHEDs). Cells from the pulp of three deciduous teeth were isolated and characterized to confirm their stem cell nature. In second passage, part of the cells were submitted to normal conditions of cell culture (Control group), while part of the cells were maintained in 10% DMSO diluted in foetal bovine serum and submitted to the following cryopreservation protocol: 2 h at 4 °C, 18 h at -20 °C and then at -80 °C for two intervals (30 days - Cryopreservation I; and 180 days Cryopreservation II). Cell proliferation and cell cycle were evaluated at intervals of 24, 48 and 72 h after plating, and apoptosis-related events were analyzed at 72 h. All groups exhibited an increase in the number of cells, and no significant differences between the cryopreserved and control groups were observed (p > .05). The distribution of cells in the cell cycle phases was consistent with cell proliferation, and the percentage of viable cells was higher than 99% in all groups, indicating that cell viability was not affected by the cryopreservation protocol throughout the experiment. The proposed cryopreservation protocol is adequate for the storage of SHED, permitting their use in future experimental studies.

Supernumerary impacted teeth in a patient with SOX2 anophthalmia syndrome.

PubMed

Numakura, Chikahiko; Kitanaka, Sachiko; Kato, Mitsuhiro; Ishikawa, Shigeo; Hamamoto, Yoshioki; Katsushima, Yuriko; Kimura, Toshiyuki; Hayasaka, Kiyoshi

2010-09-01

SOX2 anophthalmia syndrome characteristically presents as anophthalmia or microphthalmia, with various extraocular symptoms, such as hypogonadotropic hypogonadism, brain anomaly, and esophageal abnormalities. In this report, we describe a patient with SOX2 anophthalmia syndrome complicated with a dental anomaly, multiple supernumerary impacted teeth, and persistence of deciduous teeth. Multiple supernumerary teeth are usually not solitary symptoms, but indicate systemic syndrome such as cleidocranial dysplasia. In odontogenesis, many transcriptional factors, such as BMPs, FGFs, and Wnts, play significant roles and SOX2 is known to interact with some of them. The role of SOX2 in dental development remains unknown, however, multiple supernumerary teeth can be considered as extraocular symptoms of SOX2 anophthalmia syndrome, rather than the coincidence of two rare diseases.

Emergence of Primary Teeth in Children of Sunsari District of Eastern Nepal

PubMed Central

Gupta, Anita; Hiremath, SS; Singh, SK; Poudyal, S; Niraula, SR; Baral, DD; Singh, RK

2007-01-01

This study assessed the timing and eruption sequence of primary teeth in children of Sunsari district of Eastern Nepal and compared the eruption pattern of males & females between various, ethnic groups. Method This cross-sectional study, included 501 subjects, aged 3 months to 60 months selected by simple random sampling method. The determinant variables such as age, gender, ethnicity, and eruption of teeth were recorded. Results This study provides a model data on emergence of primary teeth and number of deciduous teeth in these children. This is a first study of its kind in Nepal. The findings of this study will help as a reference data for optimal use in clinical, academic, and research activities, especially for children of Eastern Nepal. PMID:18523631

[Cermet cements for milk tooth fillings. Preliminary results].

PubMed

Hickel, R; Petschelt, A; Voss, A

1989-06-01

106 Ketac-Silver fillings in deciduous molars were reevaluated after 1 to 3.3 years, i.e. 25 month on the average. About 90% of 50 occlusal fillings and about 84% of 56 multisurface restorations were unchanged. Without claiming statistical evidence for their conclusiveness, we consider these results as an indication that cermet cements are a useful alternative to amalgam fillings in deciduous teeth, particularly since the life of these fillings is limited to the time until the milk tooth is physiologically lost.

Combined Orthodontic-surgical Treatment for Skeletal Class III Malocclusion with Multiple Impacted Permanent and Supernumerary Teeth: Case Report.

PubMed

Xue, Dai Juan And Feng

2014-01-01

In this report we describe a combined orthodontic and surgical treatment for a 14-year-old boy with severe skeletal class III deformity and dental problem. His upper posterior primary teeth in the left side were over-retained and 6 maxillary teeth (bilateral central incisors and canines, left first and second premolars) were impacted, together with 5 supernumerary teeth in both arches. The treatment protocol involved extraction of all the supernumerary and deciduous teeth, surgical exposure and orthodontic traction of the impacted teeth, a bimaxillary orthognathic approach including Lefort I osteotomy. Bilateral sagittal split ramus osteotomy (BSSRO) and genioplasty was performed to correct skeletal problem. After treatment, all of the impacted teeth were brought to proper alignment in the maxillary arch. A satisfied profile and good posterior occlusion was achieved. Treatment mechanics and consideration during different stages are discussed.

Beliefs about prematurely erupted teeth in rural Yoruba communities, Nigeria.

PubMed

Oyejide, C O; Aderinokun, G A

1992-11-01

A descriptive study was carried out in two villages: Badeku and Olodo, near the city of Ibadan, between May and November 1990. The objective of the study was to investigate the knowledge, beliefs and attitudes of respondents to premature eruption of deciduous teeth in babies. Of the 622 people interviewed, a large proportion (30.5%) believed that the first deciduous tooth should erupt between the age of 5-7 months; the next commonly mentioned time of tooth eruption was 7-9 months of age; and 50.3% of the respondents claimed to have seen a case of prematurely erupted primary teeth. There was a statistically significant association between age and also between educational status of respondents and having seen premature eruption of teeth (P < 0.01). The majority of the people (53.7%) felt that the condition was an indication of an evil child. Only 22.1% of those interviewed thought it could be just an individual variation. On the recommended remedy or management of the condition, as many as 26 (4.1%) said they would get rid of the child. A high percentage felt that sacrifices should be offered to appease the gods. It is suggested that a transcultural approach be adopted in managing cases in which the parents feel particularly anxious and uncomfortable about prematurely erupted teeth in order to cater for the social well-being of the child and family. It is also recommended that appropriate health education be directed at the society as a whole concerning this condition.

Biorhythms, deciduous enamel thickness, and primary bone growth: a test of the Havers-Halberg Oscillation hypothesis.

PubMed

Mahoney, Patrick; Miszkiewicz, Justyna J; Pitfield, Rosie; Schlecht, Stephen H; Deter, Chris; Guatelli-Steinberg, Debbie

2016-06-01

Across mammalian species, the periodicity with which enamel layers form (Retzius periodicity) in permanent teeth corresponds with average body mass and the pace of life history. According to the Havers-Halberg Oscillation hypothesis (HHO), Retzius periodicity (RP) is a manifestation of a biorhythm that is also expressed in lamellar bone. Potentially, these links provide a basis for investigating aspects of a species' biology from fossilized teeth. Here, we tested intra-specific predictions of this hypothesis on skeletal samples of human juveniles. We measured daily enamel growth increments to calculate RP in deciduous molars (n = 25). Correlations were sought between RP, molar average and relative enamel thickness (AET, RET), and the average amount of primary bone growth (n = 7) in humeri of age-matched juveniles. Results show a previously undescribed relationship between RP and enamel thickness. Reduced major axis regression reveals RP is significantly and positively correlated with AET and RET, and scales isometrically. The direction of the correlation was opposite to HHO predictions as currently understood for human adults. Juveniles with higher RPs and thicker enamel had increased primary bone formation, which suggests a coordinating biorhythm. However, the direction of the correspondence was, again, opposite to predictions. Next, we compared RP from deciduous molars with new data for permanent molars, and with previously published values. The lowermost RP of 4 and 5 days in deciduous enamel extends below the lowermost RP of 6 days in permanent enamel. A lowered range of RP values in deciduous enamel implies that the underlying biorhythm might change with age. Our results develop the intra-specific HHO hypothesis. © 2016 Anatomical Society.

Anchorage onto deciduous teeth: effectiveness of early rapid maxillary expansion in increasing dental arch dimension and improving anterior crowding.

PubMed

Mutinelli, Sabrina; Manfredi, Mario; Guiducci, Antonio; Denotti, Gloria; Cozzani, Mauro

2015-01-01

Anchorage onto permanent dentition is a common procedure in rapid maxillary expansion. However, replacing first permanent molars with the second deciduous molars seems to be an option to reduce some negative side effects during orthodontic treatment. The purpose of this study was to evaluate the dental effect of rapid maxillary expansion with anchorage exclusively onto deciduous teeth performed in the first period of transition. Twenty patients with a lateral cross-bite treated exclusively by a Haas expander in early mixed dentition were retrospectively analyzed before treatment, at appliance removal, and at 21 months out of retention. The sagittal and transverse dimensions, together with the inter-canine arch and irregularity index, were digitally measured on scanned images of dental casts. The patients were compared with three balanced control groups (in total, 60 individuals) matched for gender. Two control groups had the same canine dental class as the treated group at T1, were in the inter-transitional period, and either had or lacked a lateral cross-bite. The last control group was comprised of adolescents in permanent dentition with a dental class I. The statistical analysis was performed by means of repeated-measures ANOVA for paired data and one-way ANOVA, the Kruskal-Wallis test, and the Mann-Whitney test for independent measures (α-level p < 0.05). At the end of follow-up (inter-transitional period of dentition), the dental arch dimensions of treated patients were similar to those of adolescents with a dental class I and significantly wider than those of patients with a lateral cross-bite. Also, the anterior irregularity index was lower among patients who had undergone expansion treatments than in all untreated study participants. The Haas expander anchored to the deciduous teeth is effective in increasing the dental arch width in patients with a lateral cross-bite. The dimensions of the dental arch were modified earlier toward the values of the permanent dentition.

Premaxillary-maxillary suture asymmetry in a juvenile Gorilla. Implications for understanding dentofacial growth and development.

PubMed

Schwartz, J H

1983-01-01

A specimen of juvenile gorilla was found that had the premaxillary-maxillary suture coursing between the lateral deciduous incisor and deciduous canine on one side of the jaw, but between the central and lateral deciduous incisors on the other; in the latter, the suture also separates the alveolus of the lateral deciduous incisor from the crypt of the growing successional lateral incisor. Rather than dismiss this exception to the traditional dictum of tooth identification--which is based on the position to teeth relative to this suture--as some inconsequential anomaly, an attempt is made to understand how this can occur within the confines of present understanding of dentofacial growth and development and developmental theory. An hypothesis relating tooth and tooth class identification is presented in the context of ectomesenchymally predifferentiated stem progenitors and subsequent tooth class proliferation.

Immediate periodontal bone plate changes induced by rapid maxillary expansion in the early mixed dentition: CT findings

PubMed Central

Garib, Daniela Gamba; Menezes, Maria Helena Ocké; da Silva Filho, Omar Gabriel; dos Santos, Patricia Bittencourt Dutra

2014-01-01

Objective This study aimed at evaluating buccal and lingual bone plate changes caused by rapid maxillary expansion (RME) in the mixed dentition by means of computed tomography (CT). Methods The sample comprised spiral CT exams taken from 22 mixed dentition patients from 6 to 9 years of age (mean age of 8.1 years) presenting constricted maxillary arch treated with Haas-type expanders. Patients were submitted to spiral CT scan before expansion and after the screw activation period with a 30-day interval between T1 and T2. Multiplanar reconstruction was used to measure buccal and lingual bone plate thickness and buccal bone crest level of maxillary posterior deciduous and permanent teeth. Changes induced by expansion were evaluated using paired t test (p < 0.05). Results Thickness of buccal and lingual bone plates of posterior teeth remained unchanged during the expansion period, except for deciduous second molars which showed a slight reduction in bone thickness at the distal region of its buccal aspect. Buccal bone dehiscences were not observed in the supporting teeth after expansion. Conclusion RME performed in mixed dentition did not produce immediate undesirable effects on periodontal bone tissues. PMID:25162564

Amelogenesis Imperfecta, Facial Esthetics and Snap-On Smile.

PubMed

Wilson, Lee; Bradshaw, Jonathan P; Marks, Murray K

2015-01-01

Amelogenesis imperfecta is a hereditary enamel protein disorder affecting deciduous and secondary crown formation. The prevalence ranges from 1:700 to 1:14,000 depending on the population. These teeth may be hypoplastic, hypomineralized, or hypermineralized and are often discolored, sensitive and caries vulnerable. Patients often present with psychosocial issues due to appearance. Primary teeth are often treated with stainless steel crowns while secondary teeth are treated with full coverage esthetic crowns. The presenting preteen male here was fitted with Snap-On Smile? (www.snaponsmile.com). This treatment option provided cosmetic enhancement of the patient's appearance besides stabilization without altering the primary and secondary dentition during adolescent development.

The effect of the season of birth and of selected maternal factors on linear enamel thickness in modern human deciduous incisors.

PubMed

Żądzińska, E; Kurek, M; Borowska-Strugińska, B; Lorkiewicz, W; Rosset, I; Sitek, A

2013-08-01

Development of human tooth enamel is a part of a foetus's development; its correctness is the outcome of genetic and maternal factors shaping its prenatal environment. Many authors reported that individuals born in different seasons experience different early developmental conditions during pregnancy. In this study, we investigated the effects of season of birth and selected maternal factors on enamel thickness of deciduous incisors. Dental sample comprises 60 deciduous incisors. The parents who handed over their children's teeth for research fill in questionnaires containing questions about the course of pregnancy. All teeth were sectioned in the labio-linqual plane using diamond blade (Buechler IsoMet 1000). The final specimens were observed by way of scanning electron microscopy at magnifications 80× and 320×. The thickness of total enamel (TE), prenatally (PE) and postnatally (PSE) formed enamel was measured. Children born in summer and in spring (whose first and second foetal life fall on autumn and winter) have the thinnest enamel. Season of birth, number of children in family, diseases and spasmolytic medicines using by mother during pregnancy explained almost 13% of the variability of TE. Regression analysis proved a significant influence of the season of birth and selected maternal factors on the PE thickness - these factors explained over 17% of its variability. Neither of analysed variables had influenced PSE. Our findings suggests that the thickness of enamel of deciduous incisors depends on the season of birth and some maternal factors. The differences were observed only in the prenatally formed enamel. Copyright © 2013 Elsevier Ltd. All rights reserved.

Clinical Course and Treatment of a Triplication Defect: A Case Report.

PubMed

Juneja, Suruchi; Verma, Kanika Gupta; Singh, Navneet; Sidhu, Gagandeep Kaur; Kaur, Navneet

2015-05-01

Fusion is an anomaly manifested in both deciduous and permanent dentitions. Fusion of dental tissues in the primary dentition is of clinical significance owing to the challenges in treatment of the affected teeth and aberrations encountered in development and eruption of their successors. Triple tooth refers to the union of three separate tooth entities. It can occur by fusion, germination, concrescence or a combination of both fusion and germination. Triplication is rarely encountered in the deciduous dentition. The case presented herein describes triplication of deciduous incisors and a supernumerary tooth. The diagnosis was confirmed with the help of radiographs, computed tomography (CT) imaging and histological examination. Retention of the triple tooth had led to crossbite. Extraction was performed for the triple tooth and crossbite was corrected using a composite inclined plane.

Allogeneic stem cells from deciduous teeth in treatment for periodontitis in miniature swine.

PubMed

Fu, Xiaoru; Jin, Luyuan; Ma, Ping; Fan, Zhipeng; Wang, Songlin

2014-06-01

Regeneration of lost periodontium in periodontitis is a challenge in that alveolar bone, cementum, and periodontal ligament need to be restored to their original architecture. Stem cells from exfoliated deciduous teeth (SHEDs) appear to be an attractive candidate for periodontium tissue regeneration. Previously, the authors successfully regenerated periodontal defects using autologous and allogeneic periodontal ligament stem cells (PDLSCs). The purpose of the present study is to investigate the ability of allogeneic SHEDs to regenerate lost periodontium in a swine periodontitis model. Animal models of periodontitis were established in miniature pigs, and allogeneic stem cells were isolated from miniature pig deciduous teeth (SPDs). The animal models were treated with SPDs plus hydroxyapatite/tricalcium phosphate (HA/TCP). Allogeneic PDLSCs plus HA/TCP or HA/TCP alone were set as positive control or control, respectively. Clinical assessments, computed tomography (CT) scanning, and histologic examination were used to evaluate the outcome of tissue regeneration. Clinical indices including probing depth, gingival recession, and attachment loss showed significant restoration in the SPD and PDLSC treatment groups, compared to the HA/TCP group 12 weeks post-transplantation. Meanwhile, CT scans showed that 75% of the samples had successful hard-tissue regeneration in both PDLSC and SPD groups, compared to the HA/TCP group, where the success rate was only 25%. In addition, histologic examination demonstrated that SPD and PDLSC treatment brought about remarkable regeneration of periodontal tissues, whereas periodontal regeneration was rare in the HA/TCP group. Allogeneic SPDs can effectively repair hard and soft tissue loss brought about by periodontitis in a swine model. Allogeneic SHEDs, which are easily accessible, may be applied to treat periodontitis in clinics in the future.

Does dental caries affect dental development in children and adolescents?

PubMed Central

Dhamo, Brunilda; Elezi, Besiana; Kragt, Lea; Wolvius, Eppo B; Ongkosuwito, Edwin M

2018-01-01

Although a link between dietary changes, caries, and dental development has been observed, the literature provides little insight about this relationship. The aim of our study was to investigate the association between dental caries and dental development in a clinical sample of Albanian children and adolescents. In total, 118 children and adolescents, born between 1995 and 2004 and aged 6–15 years, were included. Dental caries in the deciduous dentition was assessed using the Decayed, Filled Teeth (dft) index and dental caries in the permanent dentition was assessed using the Decayed, Missing, Filled Teeth (DMFT) index. Dental development during the permanent dentition was determined using the Demirjian method. Linear and ordinal regression models were applied to analyze the associations of dental caries with dental age and developmental stages of each left mandibular tooth. Dental caries in the deciduous dentition, estimated as a median dft of 2.0 (90% range, 0.0–9.1), was significantly associated with lower dental age (β = -0.21; 90% CI: -0.29, -0.12) and with delayed development of the canine, both premolars, and the second molar. Untreated dental caries (dt) was associated with lower dental age (β = -0.19; 90% CI: -0.28, -0.10). Dental caries in the permanent dentition, estimated as a median DMFT of 1.0 (90% range, 0.0–8.0), was not significantly associated with dental age (β = 0.05; 90% CI: -0.04, 0.14). However, the DMFT was associated with the advanced stages of development of both premolars and the second molar. The untreated dental caries in the deciduous dentition delays the development of permanent teeth. PMID:29659350

Stem cells from human exfoliated deciduous teeth (SHED) enhance wound healing and the possibility of novel cell therapy.

PubMed

Nishino, Yudai; Yamada, Yoichi; Ebisawa, Katsumi; Nakamura, Sayaka; Okabe, Kazuto; Umemura, Eri; Hara, Kenji; Ueda, Minoru

2011-05-01

In recent years, stem cells from human exfoliated deciduous teeth (SHED) have received attention as a novel stem cell source with multipotent potential. We examined the effect on wound-healing promotion with unique stem cells from deciduous teeth as a medical waste. An excisional wound-splinting mouse model was used and the effect of wound healing among SHED, human mesenchymal stromal cells (hMSCs), human fibroblasts (hFibro) and a control (phosphate-buffered saline; PBS) was evaluated by macroscopy, histology and enzyme-linked immunosorbent assay (ELISA), and the expression of hyaluronan (HA), which is related to wound healing, investigated. SHED and hMSCs accelerated wound healing compared with hFibro and the control. There was a statistically significant difference in wound healing area among hFibro, hMSCs and SHED compared with the control after day 5. At days 7 and 14 after cell transplantation, the histologic observation showed that transplanted PKH26-positive cells were surrounded by human HA binding protein, especially in hMSCs and SHED. HA expression volume values were 1558.41 ± 60.33 (control), 2092.75 ± 42.56 (hFibro), 2342.07 ± 188.10 (hMSCs) and 2314.85 ± 164.91 (SHED) ng/mg, respectively, and significantly higher in hMSCs and SHED compared with hFibro and control at days 7 and 14 (P < 0.05). Our results show that SHED hMSCs have similar effects of wound-healing promotion as hFibro and controls. This implies that SHED might offer a unique stem cell resource and the possibility of novel cell therapies for wound healing in the future.

Multiple tooth anomalies in a nonsyndromic patient with class II division 2 malocclusions: A case report and a literature review.

PubMed

Isman, E; Isman, O; Aktan, A M; Ciftci, E; Topcuoglu, T

2015-01-01

Reports in the literature about the craniofacial characteristics of patients with class II division 2 malocclusions show a lot of different patterns accompanied by palatally displaced upper incisors, congenital missing teeth, polydiastema, fusion, germination, tooth impaction, peg-shaped lateral incisors, persistent teeth, hypodontia, persistent deciduous teeth, transpositions, and supernumerary teeth. The following case report focuses on the description of the clinical characteristics observed on a patient with a very unusual conjunction of dental and skeletal anomalies mentioned above, as well as a literature review on the related issues. Extra-intra-oral examinations, radiographic evaluations, orthodontic consultation, and reviewing the literature concluded that this nonsyndromic patient that refused to receive all dental treatment approaches is special with its uniqueness.

"Redefining smile-a multidisciplinary approach".

PubMed

Manne, Prakash; Zakkula, Srujana; Atla, Jyothi; Muvva, Suresh Babu; Sampath, Anche

2013-07-01

This article presents a case report of a 20 year old female who was very much dissatisfied with her facial appearance and smile.On examination, it was found that there was a Angles class II division 1 malocclusion and a generalised spacing in the anterior teeth, with a retained, deciduous, left maxillary canine and a malposed 15. On radiographic examination, an impacted 18, 23 was noticed. As the part of the treatment plan, the retained deciduous canine and the impacted permanent canine were extracted and an orthodontic correction of the malocclusion was accomplished. The missing canine was planned to be replaced with a fixed partial denture.The short clinical crown height of the abutment teeth was increased by crown lengthening procedures and the pontic space was contoured to receive a ovate pontic by using diode lasers. The missing tooth was restored by using an all ceramic three unit zirconia bridge. This multi-disciplinary approach improved the smile of the patient and it ultimately enhanced her aesthetics and self confidence.

“Redefining Smile-A Multidisciplinary Approach”

PubMed Central

Manne, Prakash; Zakkula, Srujana; Atla, Jyothi; Muvva, Suresh Babu; Sampath, Anche

2013-01-01

This article presents a case report of a 20 year old female who was very much dissatisfied with her facial appearance and smile.On examination, it was found that there was a Angles class II division 1 malocclusion and a generalised spacing in the anterior teeth, with a retained, deciduous, left maxillary canine and a malposed 15. On radiographic examination, an impacted 18, 23 was noticed. As the part of the treatment plan, the retained deciduous canine and the impacted permanent canine were extracted and an orthodontic correction of the malocclusion was accomplished. The missing canine was planned to be replaced with a fixed partial denture.The short clinical crown height of the abutment teeth was increased by crown lengthening procedures and the pontic space was contoured to receive a ovate pontic by using diode lasers. The missing tooth was restored by using an all ceramic three unit zirconia bridge. This multi–disciplinary approach improved the smile of the patient and it ultimately enhanced her aesthetics and self confidence. PMID:23998114

Determination of physical height from crown dimensions of deciduous tooth: A dental morphometric study.

PubMed

Ramanna, C; Kamath, Venkatesh V; Sharada, C; Srikanth, N

2016-01-01

Dental morphometrics is a subject of great significance in forensic odontology in identification of an individual. Use of teeth to represent a physical profile is valuable for identification of an individual. The present study aims to assess the clinical crown length (CL) of erupted deciduous teeth and height of the child. A correlation of these parameters was attempted to arrive at a mathematical equation which would formulate a ratio of tooth CL to individual height that would support in estimating the probable height of the child. About 60 children (30 males and 30 females) of age ranged from 3-6 years were included in this study. Clinical vertical CLs of the deciduous dentition (tooth numbers 51, 52, 53, 54, and 55) were calculated using digital Vernier calipers (Aerospace Ltd., Bengaluru, Karnataka, India) on the cast models. Child height was measured using a standard measuring tape. Ratios of deciduous CL to height of the child were recorded. Linear stepwise forward regression analysis was applied to predict the probability of CL of a tooth most likely to support in prediction of physical height of the child. Tabulated results showed a probable correlation between tooth CL and height of the child. Tooth CLs of deciduous upper right second molar (55) among the males, lateral incisor (52) among females, and canine (53) using the combined male and female data were statistically significant, and they approximately predicted the child height with minimal variations. Mathematically derived equations based on linear stepwise forward regression analysis using sixty children data are height prediction (derived from combined data of male and female children) = 400.558 + 90.264 (53 CL), male child height prediction (derived from data of male children) = 660.290 + 72.970 (55 CL), and female child height prediction (derived from data of female children) = -187.942 + 194.818 (52 CL). In conclusion, clinical vertical CL is an important parameter in prediction of individual height and possible identification of the individual. An extension of the similar technique to all the deciduous dentition using a larger group of children would probably give us the best options available among vertical CLs for prediction of the child height.

The effect of working time on the displacement of Biodentine™ beneath prefabricated stainless steel crown: a laboratory study.

PubMed

Dawood, Alaa E; Manton, David J; Parashos, Peter; Wong, Rebecca H K

2016-11-01

To investigate the displacement of Biodentine ™ following cementation of stainless steel crowns (SSC) with glass-ionomer cement (GIC) on plastic deciduous teeth prepared for pulpotomy. Twenty plastic teeth with prepared occlusal cavities were divided into four groups and had Biodentine ™ placed as a mock pulpotomy agent. The pulp chamber was filled with freshly mixed Biodentine ™ then a GIC-loaded SSC was seated on the tooth using a standardized seating force for periods of: 1 min (Group 1); 2 min (Group 2), 3 min (Group 3) and 6 min (Group 4) after mixing. After 24 h at 37°C and 90% humidity, the crowns were sectioned mesio-distally and standardized digital photographs taken. Image analysis software was used to determine the ratio of the surface area of displaced Biodentine ™ relative to the surface area of the pulp chamber. The thinnest section of the remaining Biodentine ™ was measured. The lowest values of Biodentine ™ displacement and the highest values of remaining Biodentine ™ thickness were associated with Group 4. There were no significant differences between the results in Group 3 and Group 4. Within the limitations of this in vitro study, a GIC-loaded SSC can be seated on Biodentine ™ placed into a pulp chamber 3 min after mixing. © 2015 Wiley Publishing Asia Pty Ltd.

The variation in surface morphology and hardness of human deciduous teeth samples after laser irradiation

NASA Astrophysics Data System (ADS)

Khalid, Arooj; Bashir, Shazia; Akram, Mahreen; Salman Ahmed, Qazi

2017-11-01

The variation in surface morphology and hardness of human deciduous teeth samples has been investigated after laser irradiation at different wavelengths and energies. Nd:YAG was employed as a source of irradiation for IR (1064 nm) and visible (532 nm) radiation, whereas an excimer laser was used as the source of UV (248 nm) radiation. Scanning electron microscope (SEM) analysis was carried out to reveal the surface morphological evolution of teeth samples. Vickers microhardness tester was employed to investigate the modifications in the hardness of the laser-treated samples. It is observed from SEM analysis that IR wavelength is responsible for ablation of collagen matrix and intertubular dentine. For visible radiation, the ablation of collagen along with hydroxypatite is observed. With UV radiation, the ablation of peritubular dentine is dominant and is responsible for the sealing of tubules. The decrease in hardness at lower energy for both wavelengths is due to the evaporation of carbon content. With increasing energy, evaporation of water along with carbon content, and resolidification and re-organization of inorganic content causes the increase in hardness of the treated dentine. SEM as well as microhardness analyses reveal that laser wavelengths and energy of laser radiation significantly influence the surface morphology and hardness of samples.

Wnt/β-Catenin Signaling Determines the Vasculogenic Fate of Postnatal Mesenchymal Stem Cells.

PubMed

Zhang, Zhaocheng; Nör, Felipe; Oh, Min; Cucco, Carolina; Shi, Songtao; Nör, Jacques E

2016-06-01

Vasculogenesis is the process of de novo blood vessel formation observed primarily during embryonic development. Emerging evidence suggest that postnatal mesenchymal stem cells are capable of recapitulating vasculogenesis when these cells are engaged in tissue regeneration. However, the mechanisms underlining the vasculogenic differentiation of mesenchymal stem cells remain unclear. Here, we used stem cells from human permanent teeth (dental pulp stem cells [DPSC]) or deciduous teeth (stem cells from human exfoliated deciduous teeth [SHED]) as models of postnatal primary human mesenchymal stem cells to understand mechanisms regulating their vasculogenic fate. GFP-tagged mesenchymal stem cells seeded in human tooth slice/scaffolds and transplanted into immunodeficient mice differentiate into human blood vessels that anastomize with the mouse vasculature. In vitro, vascular endothelial growth factor (VEGF) induced the vasculogenic differentiation of DPSC and SHED via potent activation of Wnt/β-catenin signaling. Further, activation of Wnt signaling is sufficient to induce the vasculogenic differentiation of postnatal mesenchymal stem cells, while Wnt inhibition blocked this process. Notably, β-catenin-silenced DPSC no longer differentiate into endothelial cells in vitro, and showed impaired vasculogenesis in vivo. Collectively, these data demonstrate that VEGF signaling through the canonical Wnt/β-catenin pathway defines the vasculogenic fate of postnatal mesenchymal stem cells. Stem Cells 2016;34:1576-1587. © 2016 AlphaMed Press.

Variation in elemental intensities among teeth and between pre- and postnatal regions of enamel.

PubMed

Dolphin, Alexis E; Goodman, Alan H; Amarasiriwardena, Dulasiri D

2005-12-01

Microspatial analyses of the trace element composition of dental enamel are made possible using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Fine spatial resolution, multielement capabilities, and minimal sample destruction make this technique particularly well-suited for documenting the distribution of elements in sequentially calcifying layers of enamel. Because deciduous enamel forms from week 13 in utero up to 9 months postnatally (thereafter essentially becoming inert), the application of LA-ICP-MS allows for the retrospective measurement of prenatal and early postnatal trace-element uptake during a critical period of child development. In this study, we compared intra- and intertooth intensities of 25Mg, 57Fe, 66Zn, 68Zn, 88Sr, 138Ba, and 208Pb via LA-ICP-MS of 38 exfoliated deciduous incisors and canines donated by 36 participants in the Solís Valley Mexico Nutrition Collaborative Research Support Program (NCRSP). Pre- and postnatal comparisons within teeth showed significant increases (P < 0.001) and greater variation in the abundance of all isotopes in postnatal enamel, with the exception of a decrease in 25Mg (P < 0.001) and constant values for 88Sr (P = 0.681). Conversely, comparisons by tooth type and mouth quadrant revealed few significant differences between teeth of the same individual. We argue that more variation in the trace element composition of teeth occurs across developmental areas within a tooth than among different teeth of the same person. This study further demonstrates that sequentially calcifying areas of enamel have different chemical concentrations. The results support the use of microspatial analyses of enamel for understanding changes in nutrition, pollution, and residence. 2005 Wiley-Liss, Inc.

Shear bond strength of different types of adhesive systems to dentin and enamel of deciduous teeth in vitro.

PubMed

Kensche, A; Dähne, F; Wagenschwanz, C; Richter, G; Viergutz, G; Hannig, C

2016-05-01

The present study aimed to evaluate the suitability of self-etch adhesives for restoration of deciduous teeth compared with etch and rinse approaches. One hundred twenty primary teeth were divided into five groups, each being assigned to an adhesive system. Self-etch adhesives XenoV (XV) and Clearfil S(3) Bond (CB), Prime&Bond NT with (PBE)/without preliminary etching (PBN), and Optibond FL (OBFL) as an etch and rinse system were included. Enamel and dentin specimens were prepared (n = 36/group), adhesives applied, and compomer cylinders polymerized. After 24-h storage in 37 °C distilled water and thermo-cycling (1440 cycles, 5/55 °C, 27 s), shear bond tests and fracture mode classification based on SEM investigation were performed. Statistical analysis involved ANOVA and Scheffé procedure with Bonferroni-Holm correction (p ≤ 0.005). High shear bond strengths to primary enamel were determined for PBE (mean [M] = 22.48 ± 7.7 MPa) > OBFL (M = 19.06 ± 5.62 MPa) > CB (M = 17.6 ± 6.55 MPa), and XV (M = 16.85 ± 5.38 MPa) and PBN (M = 8.26 ± 4.46 MPa) formed significantly less reliable enamel-resin interfaces (p ≤ 0.005). PBE generated the highest bond strength on primary dentin (M = 21.97 ± 8.02 MPa); significantly lower values were measured for XV (M = 13.44 ± 5.43 MPa) and OBFL (M = 12.92 ± 4.31 MPa) (p ≤ 0.005). Adhesives requiring preliminary etching ensure optimal bond strength to primary enamel. If separate etching is to be avoided, selected self-etch adhesives obtain acceptable shear bond values on primary enamel and dentin. The treatment of pediatric patients presents a great challenge in dental practice, and optimization of treatment processes is important.

Enamel Microcracks Induced by Simulated Occlusal Wear in Mature, Immature, and Deciduous Teeth

PubMed Central

Ijbara, Manhal; Tabata, Makoto J.; Wada, Junichiro; Miyashin, Michiyo

2018-01-01

Enamel wear, which is inevitable due to the process of mastication, is a process in which the microcracking of enamel occurs due to the surface contacting very small hard particles. When these particles slide on enamel, a combined process of microcutting and microcracking in the surface and subsurface of the enamel takes place. The aim of this study was to detect microscopic differences in the microcrack behavior by subjecting enamel specimens derived from different age groups (immature open-apex premolars, mature closed-apex premolars, and deciduous molars) to cycles of simulated impact and sliding wear testing under controlled conditions. Our findings indicated that the characteristics of the microcracks, including the length, depth, count, orientation, and relation to microstructures differed among the study groups. The differences between the surface and subsurface microcrack characteristics were most notable in the enamel of deciduous molars followed by immature premolars and mature premolars whereby deciduous enamel suffered numerous, extensive, and branched microcracks. Within the limitations of this study, it was concluded that enamel surface and subsurface microcracks characteristics are dependent on the posteruptive age with deciduous enamel being the least resistant to wear based on the microcrack behavior as compared to permanent enamel. PMID:29850534

Rapid Palatal Expansion in the absence of posterior cross-bite to intercept maxillary incisor crowding in the mixed dentition: a CBCT evaluation of spontaneous changes of untouched permanent molars.

PubMed

Rosa, M; Lucchi, P; Manti, G; Caprioglio, A

2016-12-01

The aim of this study was to investigate the reaction of untouched permanent molars following RPE, anchored on deciduous teeth in the early mixed dentition, aimed to solve maxillary anterior crowding in the absence of posterior cross-bite. A prospective clinical trial comprised 35 consecutive patients (20 males and 15 females) treated by the same orthodontist (MR). All patients showed crowding of the upper permanent incisors in the early mixed dentition in the absence of posterior cross-bite. RPE was anchored on second deciduous molars and on the deciduous canines. CBCT was taken before and after the removal of the RPE appliance. The transverse linear changes in width and the variation in the torque of the permanent molars were measured in the coronal plane. Relief of incisor crowding was found in all patients. The transverse width between permanent molars increased significantly. The apices of the upper permanent molars spontaneously expanded more than the crowns, while the opposite happened on the lower permanent molars. Moreover, the untouched upper permanent molars spontaneously uprighted palatally, while the lower permanent molars spontaneously uprighted buccally. The variation in the torque of the permanent molars mirrored transverse normal growth. In the early mixed dentition and in the absence of posterior cross-bite, it is possible to expand transversally the palate while uprighting the upper permanent molars in the opposite direction. RPE anchored on the deciduous teeth in the early mixed dentition, in the absence of posterior cross-bite, provides an "anticipation of transverse growth" and could be indicated to expand the anterior portion of the maxillary arch perimeter to solve upper incisor crowding.

Heavy Metal in Children's Tooth Enamel: Related to Autism and Disruptive Behaviors?

ERIC Educational Resources Information Center

Abdullah, Maryam M.; Ly, Agnes R.; Goldberg, Wendy A.; Clarke-Stewart, K. Alison; Dudgeon, John V.; Mull, Christopher G.; Chan, Tony J.; Kent, Erin E.; Mason, Andrew Z.; Ericson, Jonathon E.

2012-01-01

To examine possible links between neurotoxicant exposure and neuropsychological disorders and child behavior, relative concentrations of lead, mercury, and manganese were examined in prenatal and postnatal enamel regions of deciduous teeth from children with Autism Spectrum Disorders (ASDs), high levels of disruptive behavior (HDB), and typically…

Teeth eruption in children with normal occlusion and malocclusion.

PubMed

Legović, Mario; Legović, Asja; Slaj, Martina; Mestrović, Senka; Lapter-Varga, Marina; Slaj, Mladen

2008-06-01

The aim of this study was to assess the differences in eruption of permanent teeth (C, P1, P2 and M2) in a group of children with and without malocclusion. A sample of 1758 children (921 boys and 837 girls), aged 8-13 was randomly selected. The subjects were grouped by chronological age (11 groups) and by presence of malocclusion. Statistically significant differences were found for both, upper and lower canines in the age group 11 (p<0.01). Statistically significant difference was found in the age group 8.5 for upper first (p<0.05), upper second premolars (p<0.01) in the age group 10, and the lower second premolars in the age group 11 (p<0.05). Premature loss of deciduous teeth caused early eruption of succedaneus permanent teeth, possibly leading to development of a malocclusion.

Dental maturation, eruption, and gingival emergence in the upper jaw of newborn primates.

PubMed

Smith, Timothy D; Muchlinski, Magdalena N; Jankord, Kathryn D; Progar, Abbigal J; Bonar, Christopher J; Evans, Sian; Williams, Lawrence; Vinyard, Christopher J; Deleon, Valerie B

2015-12-01

In this report we provide data on dental eruption and tooth germ maturation at birth in a large sample constituting the broadest array of non-human primates studied to date. Over 100 perinatal primates, obtained from natural captive deaths, were screened for characteristics indicating premature birth, and were subsequently studied using a combination of histology and micro-CT. Results reveal one probable unifying characteristic of living primates: relatively advanced maturation of deciduous teeth and M1 at birth. Beyond this, there is great diversity in the status of tooth eruption and maturation (dental stage) in the newborn primate. Contrasting strategies in producing a masticatory battery are already apparent at birth in strepsirrhines and anthropoids. Results show that dental maturation and eruption schedules are potentially independently co-opted as different strategies for attaining feeding independence. The most common strategy in strepsirrhines is accelerating eruption and the maturation of the permanent dentition, including replacement teeth. Anthropoids, with only few exceptions, accelerate mineralization of the deciduous teeth, while delaying development of all permanent teeth except M1. These results also show that no living primate resembles the altricial tree shrew (Tupaia) in dental development. Our preliminary observations suggest that ecological explanations, such as diet, provide an explanation for certain morphological variations at birth. These results confirm previous work on perinatal indriids indicating that these and other primates telegraph their feeding adaptations well before masticatory anatomy is functional. Quantitative analyses are required to decipher specific dietary and other influences on dental size and maturation in the newborn primate. © 2015 Wiley Periodicals, Inc.

Dental maturation, eruption, and gingival emergence in the upper jaw of newborn primates

PubMed Central

Smith, Timothy D.; Muchlinksi, Magdalena N.; Jankord, Kathryn D.; Progar, Abbigal J.; Bonar, Christopher J.; Evans, Sian; Williams, Lawrence; Vinyard, Christopher J.; DeLeon, Valerie B.

2015-01-01

In this report we provide data on dental eruption and tooth germ maturation at birth in a large sample constituting the broadest array of non-human primates studied to date. Over 100 perinatal primates, obtained from natural captive deaths, were screened for characteristics indicating premature birth, and were subsequently studied using a combination of histology and micro-CT. Results reveal one probable unifying characteristic of living primates: relatively advanced maturation of deciduous teeth and M1 at birth. Beyond this, there is great diversity in the status of tooth eruption and maturation (dental stage) in the newborn primate. Contrasting strategies in producing a masticatory battery are already apparent at birth in strepsirrhines and anthropoids. Results show that dental maturation and eruption schedules are potentially independently co-opted as different strategies for attaining feeding independence. The most common strategy in strepsirrhines is accelerating eruption and the maturation of the permanent dentition, including replacement teeth. Anthropoids, with only few exceptions, accelerate mineralization of the deciduous teeth, while delaying development of all permanent teeth except M1. These results also show that no living primate resembles the altricial tree shrew (Tupaia) in dental development. Our preliminary observations suggest that ecological explanations, such as diet, provide an explanation for certain morphological variations at birth. These results confirm previous work on perinatal indriids indicating that these and other primates telegraph their feeding adaptations well before masticatory anatomy is functional. Quantitative analyses are required to decipher specific dietary and other influences on dental size and maturation in the newborn primate. PMID:26425925

Maternal diets, nutritional status, and zinc in contemporary Mexican infants' teeth: Implications for reconstructing paleodiets.

PubMed

Dolphin, Alexis E; Goodman, Alan H

2009-11-01

Despite attempts to use zinc (Zn) concentrations in hard tissues to comment upon the degree of carnivory in past populations, zinc has yielded inconsistent trophic level effects. The question of what, if anything, zinc in human enamel reveals regarding past diets is the focus of this research. We test whether the zinc content of deciduous tooth enamel from contemporary Mexican infants varies by maternal dietary variables such as zinc intake, proportion of animal products consumed, and dietary components that are known to impact zinc absorption. Deciduous teeth were collected from former participants in a longitudinal study of maternal and infant diet and function in highland Mexico. The Zn/Ca ratios of both prenatal and postnatal regions of 37 anterior teeth representing 26 individuals were assessed via laser ablation-inductively coupled plasma-mass spectrometry. Maternal dietary data collected during lactation were not correlated with zinc levels in the early postnatal enamel of infants' teeth, which were forming at the same time. In the case of prenatal enamel, zinc values were correlated with the consumption of foods known to influence Zn bioavailability, most notably tortillas (P = 0.008; r = 0.510), but not with meat consumption. Unexpectedly, women who consumed diets with poor zinc bioavailability during pregnancy gave birth to infants whose prenatal enamel demonstrated the highest Zn/Ca ratios, possibly due to enhanced zinc absorption during pregnancy for those mothers suffering most from long-term micronutrient deficiency. These results would suggest that zinc is not a reliable trophic level indicator.

Fragile X syndrome: panoramic radiographic evaluation of dental anomalies, dental mineralization stage, and mandibular angle.

PubMed

Sabbagh-Haddad, Aida; Haddad, Denise Sabbagh; Michel-Crosato, Edgard; Arita, Emiko Saito

2016-01-01

The purpose of this study was to evaluate the dental radiographic characteristics as described in 40 records of patients with panoramic radiography. The patients were in the range of 6-17 years old, and were divided into two groups (20 subjects who were compatible with the normality standard and 20 individuals diagnosed with the FXS), which were matched for gender and age. Analysis of the panoramic radiographic examination involved the evaluation of dental mineralization stage, mandibular angle size, and presence of dental anomalies in both deciduous and permanent dentitions. The results of radiographic evaluation demonstrated that the chronology of tooth eruption of all third and second lower molars is anticipated in individuals with FXS (p<0.05). In this group, supernumerary deciduous teeth (2.83%), giroversion of permanent teeth (2.31%), and partial anodontia (1.82%) were the most frequent dental anomalies. In addition, an increase was observed in the mandibular angle size in the FXS group (p<0.05). We conclude that knowledge of dental radiographic changes is of great importance for dental surgeons to plan the treatment of these individuals.

The first modern Europeans.

PubMed

Benazzi, Stefano

2012-01-01

The discovery of new human fossil remains is one of the most obvious ways to improve our understanding of the dynamics of human evolution. The reanalysis of existing fossils using newer methods is also crucial, and may lead to a reconsideration of the biological and taxonomical status of some specimens, and improve our understanding of highly debated periods in human prehistory. This is particularly true for those remains that have previously been studied using traditional approaches, with only morphological descriptions and standard calliper measurements available. My own interest in the Uluzzian, and its associated human remains grew from my interest in applying recently developed analytical techniques to quantify morphological variation. Discovered more than 40 years ago, the two deciduous molars from Grotta del Cavallo (Apulia, Italy) are the only human remains associated with the Uluzzian culture (one of the main three European "transitional" cultures). These teeth were previously attributed to Neanderthals. This attribution contributed to a consensus view that the Uluzzian, with its associated ornament and tool complexes, was produced by Neanderthals. A reassessment of these deciduous teeth by means of digital morphometric analysis revealed that these remains belong to anatomically modern humans (AMHs). This finding contradicts previous assumptions and suggests that modern humans, and not Neanderthals, created the Uluzzian culture. Of equal importance, new chronometric analyses date these dental remains to 43,000-45,000 cal BP. Thus, the teeth from Grotta del Cavallo represent the oldest European AMH currently known.

FT-Raman spectroscopy, µ-EDXRF spectrometry, and microhardness analysis of the dentin of primary and permanent teeth.

PubMed

Torres, Carolina Paes; Miranda Gomes-Silva, Jaciara; Menezes-Oliveira, Maria Angélica Hueb; Silva Soares, Luís Eduardo; Palma-Dibb, Regina Guenka; Borsatto, Maria Cristina

2018-05-01

The chemical compositions (organic and inorganic contents) and mechanical behaviors of the dentin of permanent and deciduous teeth were analyzed and compared using X-ray fluorescence spectrometry (µ-EDXRF) Fourier transform Raman spectroscopy (FT-Raman) and a microhardness test (HD). Healthy fresh human primary and permanent molars (n = 10) were selected, The buccal surfaces facing upwards were stabilized in an acrylic plate, flattened, polished, and submitted to the µ-EDXRF, FT-Raman, and HD analysis. The results of the analysis were subjected to ANOVAs and Mann-Whitney U/Student's t multiple comparisons tests. The data showed similar values for the dentin of the primary and permanent teeth in P content, organic content (amide I peak), inorganic content ( PO43- - 430 and 590), and microhardness, Nevertheless, Ca content and Ca/P weight ratio were higher, and the CO32- peak was lower in the dentin of the permanent teeth compared to primary teeth. It be concluded that despite permanent teeth showed more Ca element, both substrates showed similar behavior of chemical and physical properties. © 2018 Wiley Periodicals, Inc.

Tracing fetal and childhood exposure to lead using isotope analysis of deciduous teeth

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

Shepherd, Thomas J.; British Geological Survey, Keyworth, Nottingham; Dirks, Wendy

We report progress in using the isotopic composition and concentration of Pb in the dentine and enamel of deciduous teeth to provide a high resolution time frame of exposure to Pb during fetal development and early childhood. Isotope measurements (total Pb and {sup 208}Pb/{sup 206}Pb, {sup 207}Pb/{sup 206}Pb ratios) were acquired by laser ablation inductively coupled mass spectrometry at contiguous 100 micron intervals across thin sections of the teeth; from the outer enamel surface to the pulp cavity. Teeth samples (n=10) were selected from two cohorts of children, aged 5–8 years, living in NE England. By integrating the isotope datamore » with histological analysis of the teeth, using the daily incremental lines in dentine, we were able to assign true estimated ages to each ablation point (first 2–3 years for molars, first 1–2 years for incisors+pre-natal growth). Significant differences were observed in the isotope composition and concentration of Pb between children, reflecting differences in the timing and sources of exposure during early childhood. Those born in 2000, after the withdrawal of leaded petrol in 1999, have the lowest dentine Pb levels (<0.2 µg Pb/g) with {sup 208}Pb/{sup 206}Pb (mean ±2σ: 2.126–2.079) {sup 208}Pb/{sup 206}Pb (mean ±2σ: 0.879–0.856) ratios that correlate very closely with modern day Western European industrial aerosols (PM{sub 10}, PM{sub 2.5}) suggesting that diffuse airborne pollution was probably the primary source and exposure pathway. Legacy lead, if present, is insignificant. For those born in 1997, dentine lead levels are typically higher (>0.4 µgPb/g) with {sup 208}Pb/{sup 206}Pb (mean ±2σ: 2.145–2.117) {sup 208}Pb/{sup 206}Pb (mean ±2σ: 0.898–0.882) ratios that can be modelled as a binary mix between industrial aerosols and leaded petrol emissions. Short duration, high intensity exposure events (1–2 months) were readily identified, together with evidence that dentine provides a good proxy for childhood changes in the isotope composition of blood Pb. Our pilot study confirms that laser ablation Pb isotope analysis of deciduous teeth, when carried out in conjunction with histological analysis, permits a reconstruction of the timing, duration and source of exposure to Pb during early childhood. With further development, this approach has the potential to study larger cohorts and appraise environments where the levels of exposure to Pb are much higher. - Highlights: • Reconstructing a high resolution chronology of early childhood exposure to lead. • Combined laser ablation lead isotope – histological analysis of children's teeth. • Using dentine to recover information on the intensity, duration and source of lead. • Importance of industrial airborne lead pollution in a post-leaded petrol era.« less

Oral health status of handicapped primary school pupils in Dar es Salaam, Tanzania.

PubMed

Simon, E N M; Matee, M I; Scheutz, F

2008-03-01

There is hardly any information regarding oral health status of handicapped primary school pupils in Tanzania. Determination of their oral health status could help in planning sustainable intervention programmes for this disadvantaged group. To determine caries and periodontal status and treatment needs of handicapped primary school pupils in Dar es Salaam, Tanzania. A descriptive cross-sectional study. Uhuru Mchanganyiko and Buguruni special schools, Dar es Salaam. The sample consisted of 179 (55.8%) males and 142 (44.2%) females aged between 7 and 22 years. Majority (71%) were deaf followed by blind (17.8%) and mentally retarded (8.7%). Six (1.9%) pupils were both deaf and blind, while one (0.3%) pupil was blind and mentally retarded. Forty one (12.8%) pupils had at least one decayed deciduous tooth, with the mean (dmfs) ranging from 0.25 to 3.24. The deaf had the highest mean decayed surfaces, followed by the mentally retarded and the blind. There was only one (0.3%) pupil who had a filled deciduous tooth. Thirty three (10.3%) pupils had decayed permanent teeth and 31 (9.7%) had missing permanent teeth. None of the decayed permanent teeth were restored. The blind had the lowest mean deciduous surfaces (DS) scores of between 0 and 1.0. In the mentally retarded group the mean DS ranged from 0.25 to 1.75. About 73.5% of the studied group had bleeding of the gums, with the blind having the highest mean bleeding index scores (p < 0.001) and about 82.8% of the pupils had calculus, with highest mean scores mainly among the blind (p = 0.008). The caries prevalence among handicapped primary school pupils was quite low. However, there was relatively high level of gingival bleeding and calculus. Regarding treatment needs, 23% required dental fillings mainly of one and two surface restorations and 82% required scaling and polishing. Despite these treatment needs these pupils had not received any dental attention.

A Changing Trend In Eruption Age and Pattern of First Deciduous Tooth: Correlation to Feeding Pattern

PubMed Central

Kohli, Monika V; Patil, Gururaj B.; Kulkarni, Narayan B.; Bagalkot, Kishore; Purohit, Zarana; Dave, Nilixa; Sagari, Shitalkumar G; Malaghan, Manjunath

2014-01-01

Background: Feeding mode during infancy and its effect on deciduous tooth appearance in oral cavity in two generations and among genders. Aim and Objective: Study aimed to compare and correlate times and patterns of deciduous tooth eruption in breastfeeding (OBF), partial breastfeeding (PBF) and spoon feeding (SF) infants and initiation of semisolid food feeding (SSF) in infants. It also aimed to address the variations in the time of eruption of first deciduous tooth and its pattern in two generations who had more than a decade of difference in ages. Materials and methods: An open-ended questionnaire study was conducted on mothers of 265 patients from two groups, generation 1 (G1)- adults who were aged 20-35 years and second group, generation 2 (G2) - children who were below 5 years of age . Results: A statistical significance was observed with respect to age, gender, generations, and frequency of breastfeeding, partial breastfeeding and time of initiation of semisolid food. Conclusion: There is a delayed eruption of teeth in present generation. For girls, it occurs at age of 7.88 months and for boys, it occurs at the age of 8.08 months. PMID:24783136

[Deciduous dentition: anatomical study by μ-CT].

PubMed

Bossù, Maurizio; Valletta, Alessandra; Fiore, Roberto; Riccitiello, Francesco; D'Amora, Marilina; Coppolino, Francesco; Simeone, Michele; Polimeni, Antonella

2013-01-01

Endodontics is the branch of deciduous teeth pediatric dentistry that deals with the treatment of the root canal system. The goal of therapy is to maintain as long as possible the element in the dental arch to prevent alterations of orthognathodontic, infectious, and functional history and eruptive sequence. Although manual instrumentation has been widely used and still preferred by some practitioners, has limitations that affect the actual ability to clean the channel, the ability to create steps, perforations, dentinal plugs and fractures of the instrument. On the other hand, the disadvantages are the high cost of the instruments in nickel-titanium, which must be frequently replaced, and the risk of compromising the stability of the tooth due to an excessive consumption of dentinal tissue. The use of computed microtomography (μCT) of extracted elements has a considerable advantage in the study of dental hard tissues. The purpose of this study was to analyze the anatomy of the endodontic system of the elements deciduous.

Dental Aspect of Distal Tubular Renal Acidosis with Genu Valgum Secondary to Rickets: A Case Report

PubMed Central

Bahadure, Rakesh N.; Thosar, Nilima; Kriplani, Ritika; Baliga, Sudhindra; Fulzele, Punit

2012-01-01

Distal renal tubular acidosis is a disease that occurs when the kidneys do not remove acid properly into the urine, leaving the blood too acidic (called acidosis). Distal renal tubular acidosis (type I RTA) is caused by a defect in the kidney tubes that causes acid to build up in the bloodstream. It ultimately results rickets which include chronic skeletal pain, in skeletal deformities, skeletal fractures. Rickets is among the most frequent childhood diseases in many developing countries. Dental problems in rickets include delayed eruption of permanent teeth, premature fall of deciduous teeth, defects in structure of teeth, enamel defects in permanent teeth (hypoplastic), pulp defects, intraglobular dentine, and caries tooth. Herewith, reported a case of distal tubular renal acidosis with genu valgum secondary to rickets, with pain and extraoral swelling associated with right and left mandibular 1st permanent molars. Teeth were infected with pulp without being involved with caries. Radiographically cracks in enamel and dentin were observed. Pulp revascularization with 46 and root canal treatment was done for 36 with followup of 1 year. PMID:22567455

A comparative microleakage evaluation of three different base materials in Class I cavity in deciduous molars in sandwich technique using dye penetration and dentin surface interface by scanning electron microscope.

PubMed

Niranjan, Babita; Shashikiran, Nandihalli Devendrappa; Singla, Shilpy; Thakur, Ruchi; Dubey, Aashutosh; Maran, Satish

2016-01-01

A major objective in restorative dentistry is the control of marginal leakage, which may occur because of dimensional changes or lack of adaptation of restorative material to the cavity preparation. Numerous techniques have been advocated to overcome polymerization shrinkage in composite restorations. This study investigated microleakage of three different bases under composite resin in sandwich technique using dye penetration and dentin surface interface using scanning electron microscope (SEM). Sixty extracted deciduous molars were stored in distilled water and Class I cavities with a width of about one-fourth of intercuspal distance and a depth of 0.5-1 mm below the dentino-enamel junction was prepared without bevels. In Group 1 - glass ionomer cement (GIC); Group 2 - mineral trioxide aggregate (MTA); Group 3 - Biodentine™ was placed as a base under composite. Teeth were longitudinally sectioned in two halves, through the centers of the restoration, immersed in 2% methylene blue and microleakage was evaluated under stereomicroscope and surface interface between base and dentin was evaluated under SEM. Under the condition of in vitro study, less microleakage and less internal gaps were seen in Biodentine™ (0.00 ± 0.00 and 4.00 ± 1.59) group than MTA (0.00 ± 0.00 and 6.08 ± 1.82) and GIC (25.25 ± 6.57 and 14.73 ± 3.72, respectively) and showed very strong positive correlation between microleakage and internal gaps. Biodentine™ exhibits superior marginal sealing ability as well as marginal adaptation under composite resin as compared to MTA and GIC.

[Inequalities in untreated dental caries prevalence in preschool children in Brazil].

PubMed

Ardenghi, Thiago Machado; Piovesan, Chaiana; Antunes, José Leopoldo Ferreira

2013-12-01

To evaluate the influence of social inequalities of individual and contextual nature on untreated dental caries in Brazilian children. The data on the prevalence of dental caries were obtained from the Brazilian Oral Health Survey (SBBrasil 2010) Project, an epidemiological survey of oral health with a representative sample for the country and each of the geographical micro-regions. Children aged five (n = 7,217) in 177 municipalities were examined and their parents/guardians completed a questionnaire. Contextual characteristics referring to the municipalities in 2010 (mean income, fluorodized water and proportion of residences with water supply) were supplied by the Fundação Instituto Brasileiro de Geografia e Estatística (Brazilian Institute of Geography and Statistics). Multilevel Poisson regression analysis models were used to assess associations. The prevalence of non-treated dental caries was 48.2%; more than half of the sample had at least one deciduous tooth affected by dental caries. The index of dental caries in deciduous teeth was 2.41, with higher figures in the North and Northeast. Black and brown children and those from lower income families had a higher prevalence of untreated dental caries. With regards context, the mean income in the municipality and the addition of fluoride to the water supply were inversely associated with the prevalence of the outcome. Inequalities in the prevalence of untreated dental caries remain, affecting deciduous teeth of children in Brazil. Planning public policies to promote oral health should consider the effect of contextual factors as a determinant of individual risk.

Role of Cone Beam Computed Tomography in Evaluation of Radicular Cyst mimicking Dentigerous Cyst in a 7-year-old Child: A Case Report and Literature Review.

PubMed

Mahesh, B S; P Shastry, Shilpa; S Murthy, Padmashree; Jyotsna, T R

2017-01-01

To report a rare case of large radicular cyst-associated deciduous tooth and to discuss the importance of cone beam computed tomography (CBCT) in diagnosing the condition. Radicular cyst is the most common cyst affecting the permanent teeth, but its occurrence in deciduous teeth is rare. Most of the radicular cysts are asymptomatic and are discovered accidentally when radiographs are taken. Conventional radiographs show two-dimensional images of three-dimensional objects. Cone beam computed tomography provides undistorted three-dimensional information of hard tissues and gives adequate spatial resolution. A 7-year-old child, with a complaint of swelling in the maxillary anterior region, was diagnosed with radicular cyst in relation to primary maxillary right central incisor based on CBCT and histopathological features. Early diagnosis and prompt treatment of radicular cyst in primary dentition is important to prevent damage to permanent tooth. Mahesh BS, Shastry SP, Murthy PS, Jyotsna TR. Role of Cone Beam Computed Tomography in Evaluation of Radicular Cyst mimicking Dentigerous Cyst in a 7-year-old Child: A Case Report and Literature Review. Int J Clin Pediatr Dent 2017;10(2):213-216.

Molar distalization with pendulum appliances in the mixed dentition: effects on the position of unerupted canines and premolars.

PubMed

Kinzinger, Gero S M; Wehrbein, Heinrich; Gross, Ulrich; Diedrich, Peter R

2006-03-01

The pendulum appliance allows for rapid molar distalization without the need for patient compliance. Its efficiency has been confirmed in a number of clinical studies. However, the potential interactions and positional changes between the deciduous molars used for dental anchorage and the erupted and unerupted permanent teeth have yet to be clarified when this appliance is used for molar distalization in the mixed dentition. Twenty-nine patients in the mixed dentition each received a modified pendulum appliance with a distal screw and a preactivated pendulum spring for bilateral distalization of the maxillary molars. The patients were divided into 4 groups based on dentition stages: patient group 1 (PG 1, n = 10) was in the early mixed dentition; patients had resorption of the distal root areas of the deciduous molars being used for dental anchorage, and the unerupted premolars were located at the distal margin of the deciduous molar root region. Based on radiographs taken before placement of the pendulum appliance, patient group 2 (PG 2, n = 10) was diagnosed as having a central location of the unerupted premolars. In the third group (PG 3, n = 4), the first premolars were already erupted and could be integrated into the dental anchorage, but the canines were not yet erupted. In the fourth group (PG 4, n = 5), the first premolars and both canines were fully erupted. Statistical analysis of the measured results showed significant differences in the side effects between PG 1 and PG 2. In patients being treated with pendulum appliances, the anchorage quality of the deciduous molars that were already partially resorbed in the distal root area was comparatively reduced. Consequently, the mesial drift of the deciduous molars and incisors was increased, without impairing the extent and quality of the molar distalization. Anchorage loss in the supporting area had no direct impact on the sagittal position of the unerupted premolars in the early mixed dentition. If permanent teeth have already started to erupt in the supporting area, additional space restrictions should be avoided in patients with critical topography, especially if there is little space for the unerupted canines. At this stage of the mixed dentition, premolar extraction or augmentation of the supporting area with extraoral headgear offers a therapeutic alternative to intraoral distalization appliances with exclusively dental anchorage.

An Overview of Microbiology Research in Japan, with Notes on Medical History, Education and Health Care.

DTIC Science & Technology

1981-07-01

Kyogoku: infrared spectroscopy , Raman spectroscop , and nuclear magnetic resonance spectroscopy of protein and protein models; resonance Raman spectra...Research projects - tritium labeling techniques; heavy metal accumulations in deciduous teeth; chemistry of the mycotoxin fusarenon; EM of phage P22 DNA...fluorescence correlation spectroscopy . - Biological Activities of Biopolymers - Dr. M. Kageyama, Director: Analysis of Pseudomonas aeruginosa bacteriocins

Primary tooth size asymmetry in twins and singletons.

PubMed

Heikkinen, T; Harila, V; Ollikkala, A; Alvesalo, L

2016-08-01

To explore asymmetry values of antimeric deciduous tooth crown dimensions in three types of twins: monozygotic (MZ), dizygotic same-sex (DZ) and opposite-sex (OS) vs. single-born controls. Mesiodistal and labio-lingual crown dimensions of second deciduous molars and mesiodistal canine and first molar crown dimensions of 2159 children at 6-12 years of age were evaluated, originating from the US cross-sectional Collaborative Perinatal Study from the 1970s, including altogether MZ (n = 28), DZ same-sex (n = 33) and OS (n = 39) pairs. Single born (n = 1959) were used as controls. Dental casts were measured for comparison of variance relationships calculated from antimeric teeth, exhibiting fluctuating (FA), and directional (DA) asymmetry using anova. Significant differences appeared in MZ and OS girls in DA of deciduous canines, which gain size in the first and second trimester, and deciduous second molars, which finally stop crown growth during the early post-natal period. Significantly, increased FA values appeared for lower deciduous canines and second molars, indicating greatest environmental stress in OS girls, MZ girls and DZ boys. Twin girls had more fluctuating and directional crown asymmetry than twin boys, but in some dimensions, the twins were more symmetric than controls. Transmembrane hormonal influence between opposite-sex twins, and late gestational stress factors, caused by placental malfunction and/or monochorionicity, may be involved in asymmetric growth of antimers, during critical periods of crown size gain. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Enamel hypoplasia in the middle pleistocene hominids from Atapuerca (Spain).

PubMed

Bermúdez de Castro, J M; Pérez, P J

1995-03-01

The prevalence and chronology of enamel hypoplasias were studied in a hominid dental sample from the Sima de los Huesos (SH) Middle Pleistocene site at the Sierra de Atapuerca (Burgos, northern Spain). A total of 89 permanent maxillary teeth, 143 permanent mandibular teeth, and one deciduous lower canine, belonging to a minimum of 29 individuals, were examined. Excluding the antimeres (16 maxillary and 37 mandibular cases) from the sample, the prevalence of hypoplasias in the permanent dentition is 12.8% (23/179), whereas the deciduous tooth also showed an enamel defect. No statistically significant differences were found between both arcades and between the anterior and postcanine teeth for the prevalence of hypoplasias. In both the maxilla and the mandible the highest frequency of enamel hypoplasias was recorded in the canines. Only one tooth (a permanent upper canine) showed two different enamel defects, and most of the hypoplasias were expressed as faint linear horizontal defects. Taking into account the limitations that the incompleteness of virtually all permanent dentitions imposes, we have estimated that the frequency by individual in the SH hominid sample was not greater than 40%. Most of the hypoplasias occurred between birth and 7 years (N = 18, X = 3.5, SD = 1.3). Both the prevalence and severity of the hypoplasias of the SH hominid sample are significantly less than those of a large Neandertal sample. Furthermore, prehistoric hunter-gatherers and historic agricultural and industrial populations exhibit a prevalence of hypoplasias generally higher than that of the SH hominids. Implications for the survival strategies and life quality of the SH hominids are also discussed.

Prenatal factors associated with the neonatal line thickness in human deciduous incisors.

PubMed

Kurek, M; Żądzińska, E; Sitek, A; Borowska-Strugińska, B; Rosset, I; Lorkiewicz, W

2015-06-01

The neonatal line (NNL) is used to distinguish developmental events observed in enamel which occurred before and after birth. However, there are few studies reporting relationship between the characteristics of the NNL and factors affecting prenatal conditions. The aim of the study was to determine prenatal factors that may influence the NNL thickness in human deciduous teeth. The material consisted of longitudinal ground sections of 60 modern human deciduous incisors obtained from full-term healthy children with reported birth histories and prenatal factors. All teeth were sectioned in the labio-lingual plane using diamond blade (Buechler IsoMet 1000). Final specimens were observed using scanning electron microscopy at magnifications 320×. For each tooth, linear measurements of the NNL thickness were taken on its labial surface at the three levels from the cemento-enamel junction. The difference in the neonatal line thickness between tooth types and between males and females was statistically significant. A multiple regression analyses confirmed influence of two variables on the NNL thickness standardised on tooth type and the children's sex (z-score values). These variables are the taking of an antispasmodic medicine by the mother during pregnancy and the season of the child's birth. These two variables together explain nearly 17% of the variability of the NNL. Children of mothers taking a spasmolytic medicine during pregnancy were characterised by a thinner NNL compared with children whose mothers did not take such medication. Children born in summer and spring had a thinner NNL than children born in winter. These results indicate that the prenatal environment significantly contributes to the thickness of the NNL influencing the pace of reaching the post-delivery homeostasis by the newborn's organism. Copyright © 2014 Elsevier GmbH. All rights reserved.

Taxonomic differences in deciduous upper second molar crown outlines of Homo sapiens, Homo neanderthalensis and Homo erectus.

PubMed

Bailey, Shara E; Benazzi, Stefano; Souday, Caroline; Astorino, Claudia; Paul, Kathleen; Hublin, Jean-Jacques

2014-07-01

A significant number of Middle to Late Pleistocene sites contain primarily (and sometimes only) deciduous teeth (e.g., Grotta del Cavallo, Mezmaiskaya, Blombos). Not surprisingly, there has been a recent renewed interest in deciduous dental variation, especially in the context of distinguishing Homo neanderthalensis and Homo sapiens. Most studies of the deciduous dentition of fossil hominins have focused on standard metrical variation but morphological (non-metric and morphometric) variation also promises to shed light on long standing taxonomic questions. This study examines the taxonomic significance of the crown outline of the deciduous upper second molar through principal components analysis and linear discriminant analysis. We examine whether or not the crown shape of the upper deciduous second molar separates H. neanderthalensis from H. sapiens and explore whether it can be used to correctly assign individuals to taxa. It builds on previous studies by focusing on crown rather than cervical outline and by including a large sample of geographically diverse recent human populations. Our samples include 17 H. neanderthalensis, five early H. sapiens, and 12 Upper Paleolithic H. sapiens. In addition, we include two Homo erectus specimens in order to evaluate the polarity of crown shape differences observed between H. neanderthalensis and H. sapiens. Our results show that crown outline shape discriminates H. sapiens and H. neanderthalensis quite well, but does not do well at distinguishing H. erectus from H. sapiens. We conclude that the crown outline shape observed in H. sapiens is a primitive retention and that the skewed shape observed in H. neanderthalensis is a derived condition. Finally, we explore the phylogenetic implications of the results for the H. erectus molars. Copyright © 2014 Elsevier Ltd. All rights reserved.

Clinical and radiographic evaluation of zinc oxide with aloe vera as an obturating material in pulpectomy: an in vivo study.

PubMed

Khairwa, Abhishek; Bhat, Manohar; Sharma, Rajesh; Satish, V; Maganur, Prabhadevi; Goyal, Anil Kumar

2014-01-01

Pulp therapy for pulpally involved primary teeth continues to be a challenge to clinicians. One of the major areas of continued research is in the area of finding obturating materials to suit the specific properties of these teeth. Zinc oxide eugenol is used frequently in pulpectomy for the obturation of the primary teeth. To evaluate clinically and radiographically a mixture of zinc oxide eugenol and aloe vera as an obturating material. A total of 50 children, aged between 4 and 9 years, who were screened for unilateral or bilateral carious deciduous molars were studied. Out of these, 15 children were randomly selected for endodontic treatment. Obturation was done with a mixture of zinc oxide powder and aloe vera gel. Clinical and radiographic evaluation was done after 7 days, 1 month, 3 months, 6 months, and 9 months. The data were statistically analyzed. Endodontic treatment using a mixture of zinc oxide powder and aloe vera gel in primary teeth has shown good clinical and radiographic success. A detailed observational study with longer follow-up will highlight the benefits of aloe vera in primary teeth as an obturating medium.

Effect of chitosan conduit under a dynamic culture on the proliferation and neural differentiation of human exfoliated deciduous teeth stem cells.

PubMed

Su, Wen-Ta; Shih, Yi-An; Ko, Chih-Sheng

2016-06-01

Ex vivo engineering of artificial nerve conduit is a suitable alternative clinical treatment for nerve injuries. Stem cells from human exfoliated deciduous teeth (SHEDs) have been considered as alternative sources of adult stem cells because of their potential to differentiate into multiple cell lineages. These cells, when cultured in six-well plates, exhibited a spindle fibroblastic morphology, whereas those under a dynamic culture aggregated into neurosphere-like clusters in the chitosan conduit. In this study, we confirmed that SHEDs efficiently express the neural stem cell marker nestin, the early neural cell marker β-III-tubulin, the late neural marker neuron-specific enolase and the glial cell markers glial fibrillary acidic protein (GFAP) and 2',3'-cyclic nucleotide-3'-phosphodiesterase (CNPase). The three-dimensional chitosan conduit and dynamic culture system generated fluid shear stress and enhanced nutrient transfer, promoting the differentiation of SHEDs to neural cells. In particular, the gene expressions of GFAP and CNPase increased by 28- and 53-fold, respectively. This study provides evidence for the dynamic culture of SHEDs during ex vivo neural differentiation and demonstrates its potential for cell therapy in neurological diseases. Copyright © 2013 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Effect of different cavity conditioners on microleakage of glass ionomer cement with a high viscosity in primary teeth

PubMed Central

Mazaheri, Romina; Pishevar, Leila; Shichani, Ava Vali; Geravandi, Sanas

2015-01-01

Background: Glass ionomer cement is a common material used in pediatric dentistry. The aim of this study was to evaluate the microleakage of high-viscosity glass ionomer restorations in deciduous teeth after conditioning with four different conditioners. Materials and Methods: Fifty intact primary canines were collected. Standard Class V cavities (2 mm × 1.5 mm × 3 mm) were prepared by one operator on all buccal tooth surfaces, including both enamel and dentin. The samples were divided into five groups with different conditioners (no conditioner, 20% acrylic acid, 35% phosphoric acid, 12% citric acid, and 17% ethylenediaminetetraacetic acid [EDTA]). Two-way — ANOVA, Kruskal–Wallis and Mann–Whitney tests were used to compare the means of microleakage between the five groups. The significance level was set at P < 0.05. Results: There was no significant difference between the means of microleakage in incisal (enamel) and gingival (dentin) margins (P = 0.34). Furthermore, there was no significant difference between the means of microleakage in enamel and dentin margins (P = 0.4). There was a significant difference between the means of microleakage in different groups (P = 0.03). Conclusion: Within the limitations of this study, it is suggested that 20% acrylic acid and 17% EDTA be used for cavity conditioning which can result in better chemical and micromechanical adhesion. PMID:26288623

Current overview on dental stem cells applications in regenerative dentistry.

PubMed

Bansal, Ramta; Jain, Aditya

2015-01-01

Teeth are the most natural, noninvasive source of stem cells. Dental stem cells, which are easy, convenient, and affordable to collect, hold promise for a range of very potential therapeutic applications. We have reviewed the ever-growing literature on dental stem cells archived in Medline using the following key words: Regenerative dentistry, dental stem cells, dental stem cells banking, and stem cells from human exfoliated deciduous teeth. Relevant articles covering topics related to dental stem cells were shortlisted and the facts are compiled. The objective of this review article is to discuss the history of stem cells, different stem cells relevant for dentistry, their isolation approaches, collection, and preservation of dental stem cells along with the current status of dental and medical applications.

An unusual case of ectodermal dysplasia: combating senile features at an early age

PubMed Central

Gupta, Mudit; Sundaresh, Kumbar Jayadevappa; Batra, Manu; Rathva, Vandana J

2014-01-01

Ectodermal dysplasia (ED) refers to a group of inherited diseases that have developmental defects in at least two major structures derived from the ectoderm, that is, hair, teeth, nails and sweat glands. Although more than 192 distinct disorders have been described, the most common is X-linked recessive hypohidrotic ED (Christ-Siemens-Touraine syndrome). Since such patients usually presents with missing teeth, dentists are usually the first person to diagnose such cases. Diagnosis of such cases is important because absence of sweat glands can lead to hyperthermia which can be life-threatening if proper care is not taken. Through this manuscript, we report a case of anhidrotic ED affecting deciduous and permanent dentition, which is rare. PMID:24493109

Increased occurrence of dental anomalies associated with infraocclusion of deciduous molars.

PubMed

Shalish, Miriam; Peck, Sheldon; Wasserstein, Atalia; Peck, Leena

2010-05-01

To test the null hypothesis that there is no relationship between infraocclusion and the occurrence of other dental anomalies in subjects selected for clear-cut infraocclusion of one or more deciduous molars. The experimental sample consisted of 99 orthodontic patients (43 from Boston, Mass, United States; 56 from Jerusalem, Israel) with at least one deciduous molar in infraocclusion greater than 1 mm vertical discrepancy, measured from the mesial marginal ridge of the first permanent molar. Panoramic radiographs and dental casts were used to determine the presence of other dental anomalies, including agenesis of permanent teeth, microdontia of maxillary lateral incisors, palatally displaced canines (PDC), and distal angulation of the mandibular second premolars (MnP2-DA). Comparative prevalence reference values were utilized and statistical testing was performed using the chi-square test (P < .05) and odds ratio. The studied dental anomalies showed two to seven times greater prevalence in the infraocclusion samples, compared with reported prevalence in reference samples. In most cases, the infraoccluded deciduous molar exfoliated eventually and the underlying premolar erupted spontaneously. In some severe phenotypes (10%), the infraoccluded deciduous molar was extracted and space was regained to allow uncomplicated eruption of the associated premolar. Statistically significant associations were observed between the presence of infraocclusion and the occurrence of tooth agenesis, microdontia of maxillary lateral incisors, PDC, and MnP2-DA. These associations support a hypothesis favoring shared causal genetic factors. Clinically, infraocclusion may be considered an early marker for the development of later appearing dental anomalies, such as tooth agenesis and PDC.

Relationship between pre-natal factors, the perinatal environment, motor development in the first year of life and the timing of first deciduous tooth emergence.

PubMed

Żądzińska, Elżbieta; Sitek, Aneta; Rosset, Iwona

2016-01-01

The emergence of deciduous teeth, despite being genetically determined, shows significant correlation with the pre-natal environment, maternal factors, method of infant feeding and also family socioeconomic status. However, reported results are often contradictory and rarely concern healthy, full-term children. The objective of this study was to evaluate the influence of pre-natal and maternal factors as well as the method of infant feeding on the timing of first deciduous tooth emergence in healthy, full-term infants and to examine the relationship between the psychomotor development rate and the age at first tooth. The database contained 480 records for healthy, term-born children (272 boys and 208 girls born at 37-42 weeks of gestation) aged 9-54 months. Multiple regression analysis and multi-factor analysis of variance were used to identify significant explanatory variables for the age at first tooth. The onset of deciduous tooth emergence is negatively correlated with birth weight and maternal smoking during pregnancy and positively correlated with breastfeeding and the age at which the child begins to sit up unaided. These factors have an additive effect on the age at first tooth. An earlier onset of tooth emergence in children exposed to maternal smoking during pregnancy seems to provide further evidence for disturbed foetal development in a smoke-induced hypoxic environment.

[Significance of proper oral hygiene for health condition of mouth and teeth].

PubMed

Ljaljević, Agima; Matijević, Snezana; Terzić, Natasa; Andjelić, Jasmina; Mugosa, Boban

2012-01-01

Proper mouth and teeth hygiene has influence on the prevention of a great number of diseases and very often some of them are not related only to oral cavity. Most frequent diseases of mouth and teeth such as caries and periodontal diseases are caused, among other factors, by poor oral hygiene. They are also more frequent in young population. The aim of this study was to estimate the influence of sociodemographic characteristics and hygienic habit on oral health in children aged 11-15 years. This cross-sectional study was conducted by the dental teams in dentist surgeries in Tivat Health Center between May and September 2009. The sample consisted of patients 11 to 15 years of age. A questionnaire and dental examination of mouth and teeth were used as research instruments. The examinations were conducted in accordance with the World Health Organization methodology and criteria. The data obtained from the interviews were correlated with those obtained from the clinical examinations. The results show that the majority of respondents brush their teeth twice a day and visit the dentist once in every six months. The research also shows that 57% respondents have caries of deciduous teeth and over 63% respondents of permanent teeth. Gingivitis was found in 14% and orthodontic anomalies in 44.7% respondents. A half of respondents who brush their teeth rarely have problems with gingivitis. There is a highly statistically significant difference between the occurrence of gingivitis and the frequency of teeth brushing. There is a significant difference between mouth and oral hygiene and sex as well as other sociodemographic characteristics of respondents. The study showed the correlation between occurrence of caries and the gingivitis and frequency of teeth brushing and dental visits.

Risk factors associated with deciduous tooth decay in Iraqi preschool children.

PubMed

Al-Mendalawi, Mahmood Dhahir; Karam, Nadia Taha

2014-01-01

Tooth decay (TD) is common in children with significant consequences on systemic well-being, growth and quality of life, as well as increasing the risk of decay in the permanent teeth. The aim of the present study is to define risk factors associated with deciduous TD (DTD) in Iraqi preschool children. From the 1(st) June to 31(st) December 2012, a case-control study was carried out on 684 children under the age of 6 years who attended Al-Aulwyiah pediatric teaching hospital in Baghdad. Clinical examination and World Health Organization caries diagnostic criteria for decayed, missing and filled teeth (DMFT) were applied. Data including gender, residence, socio-economic status (SES), parental education level, parental smoking, tooth brushing frequency, type of feeding during infancy and the presence of any systemic disease in the child were sought. The mean DMFT score in the case group was 2.03 ± 1.39, of which decayed teeth formed 1.93. Males had a higher mean DMFT (2.10 ± 1.08) than females (1.96 ± 1.70) but with no statistically significant difference. The study revealed that residence, SES, parental education level and tooth brushing frequency were dependent risk factors significantly associated with DTD. However, gender, parental smoking and pattern of feeding during infancy were not significantly associated with DTD. Only four children with systemic disorders (1.2%), namely asthma and congenital heart diseases, were noticed to have DTD. Pediatricians and dentists could provide dental preventive and screening measures. Confronting relevant risk factors associated with DTD and improving access to oral care services are suggested. In addition, promotion of oral health programs through school curricula is needed.

Phototherapy up-regulates dentin matrix proteins expression and synthesis by stem cells from human-exfoliated deciduous teeth.

PubMed

Turrioni, Ana Paula S; Basso, Fernanda G; Montoro, Liege A; Almeida, Leopoldina de Fátima D de; Costa, Carlos A de Souza; Hebling, Josimeri

2014-10-01

The aim of this study was to evaluate the effects of infrared LED (850nm) irradiation on dentin matrix proteins expression and synthesis by cultured stem cells from human exfoliated deciduous teeth (SHED). Near-exfoliation primary teeth were extracted (n=3), and SHED cultures were characterized by immunofluorescence using STRO-1, CD44, CD146, Nanog and OCT3/4 antibodies, before experimental protocol. The SHEDs were seeded (3×10(4) cells/cm(2)) with DMEM containing 10% FBS. After 24-h incubation, the culture medium was replaced by osteogenic differentiation medium, and the cells were irradiated with LED light at energy densities (EDs) of 0 (control), 2, or 4J/cm(2) (n=8). The irradiated SHEDs were then evaluated for alkaline phosphatase (ALP) activity, total protein (TP) production, and collagen synthesis (SIRCOL™ Assay), as well as ALP, collagen type I (Col I), dentin sialophosphoprotein (DSPP), and dentin matrix acidic phosphoprotein (DMP-1) gene expression (qPCR). Data were analyzed by Kruskal-Wallis and Mann-Whitney tests (α=0.05). Increased ALP activity and collagen synthesis, as well as gene expression of DSPP and ALP, were observed for both EDs compared with non-irradiated cells. The ED of 4J/cm(2) also increased gene expression of COL I and DMP-1. In conclusion, infrared LED irradiation was capable of biostimulating SHEDs by increasing the expression and synthesis of proteins related with mineralized tissue formation, with overall better results for the energy dose of 4J/cm(2). Phototherapy is an additional approach for the clinical application of LED in Restorative Dentistry. Infrared LED irradiation of the cavity's floor could biostimulate subjacent pulp cells, improving local tissue healing. Copyright © 2014 Elsevier Ltd. All rights reserved.

Job satisfaction and perceived future roles of Malaysian dental therapists: findings from a national survey.

PubMed

Abu Bakar, A; Mohd Nor, N A; Ab-Murat, N; Jaafar, N

2015-08-01

To assess Malaysian dental therapists' perceptions of their job satisfaction and future roles. A nationwide postal survey involving all Malaysian dental therapists who met the inclusion criteria (n = 1726). The response rate was 76.8%. All respondents were females; mean age 35.4 years (SD = 8.4). Majority were married (85.5%) and more than one-half had a working experience of <10 years (56.1%). Majority worked in community dental service (94.3%) and in urban areas (61.7%). Overall, they were highly satisfied with most aspects of their career. However, they were least satisfied with administrative workload (58.1%), career advancement opportunities (51.9%) and remuneration package; specifically income (45.2%), allowances (45.2%) and non-commensurate between pay and performance (44.0%). Majority perceived their role as very important in routine clinical tasks such as examination and diagnosis, preventive treatment, extraction of deciduous teeth and oral health promotion. However, fewer than one-half consider complex treatment such as placement of preformed crowns on deciduous teeth (37.1%) and extraction of permanent teeth (37.2%) as very important tasks. Majority expressed high career satisfaction with most aspects of their employment but expressed low satisfaction in remuneration, lack of career advancement opportunities and administrative tasks. We conclude that most Malaysian dental therapists have positive perceptions of their current roles but do not favour wider expansion of their roles. These findings imply that there was a need to develop a more attractive career pathway for therapists to ensure sustainability of effective primary oral healthcare delivery system for Malaysia's children. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Morphological variation, taxonomic distribution, and phylogenetic significance of cornuti in Tortricinae (Lepidoptera: Tortricidae)

USDA-ARS?s Scientific Manuscript database

Based on the examination of 4,218 slide-mounted preparations of male and female genitalia of tortricine moths, representing all major clades of the subfamily worldwide, we propose a classification system for cornuti based on four criteria: (1) presence/absence; (2) deciduous/non-deciduous; (3) type ...

Effect of glide path and apical preparation size on the incidence of apical crack during the canal preparation using Reciproc, WaveOne, and ProTaper Next systems in curved root canals: A stereomicroscope study.

PubMed

Topçuoğlu, Hüseyin Sinan; Düzgün, Salih; Akpek, Firdevs; Topçuoğlu, Gamze

2016-11-01

This study evaluated the effect of creating a glide path and apical preparation size on the incidence of apical cracks during canal preparation in mandibular molar teeth with curved canals. One hundred and forty extracted teeth were used. The teeth were randomly assigned to one control group or six experimental groups (n = 20 per group) for canal preparation. No preparation was performed on teeth in the control group. In three of the six experimental groups, a glide path was not created; a glide path was created on the curved mesial canals of all teeth in the remaining three experimental groups. All teeth in experimental groups were then instrumented with the following systems: Reciproc, WaveOne (WO), and ProTaper Next (PTN). Digital images of the apical root surfaces of these teeth were recorded before preparation, after instrumentation with size 25 files, and after instrumentation with size 40 files. The images were then inspected for the presence of any new apical cracks and propagation. There was no significant difference between the experimental groups during canal preparation using size 25 files (p > 0.05). Reciproc and WO caused more new apical cracks than did PTN during canal preparation using size 40 files (p < 0.05). However, canal preparation using size 40 files did not cause propagation of existing cracks (p > 0.05). Performing a glide path prior to canal preparation did not change the incidence of apical crack during preparation. Additionally, increasing apical preparation size may increase the incidence of apical crack during canal preparation. SCANNING 38:585-590, 2016. © 2016 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

Dental development of Didelphis albiventris (Marsupialia): I--incisors and canines.

PubMed

Fonseca, C T; Alves, J B

2006-02-01

The formation of incisors and canines in marsupials of D. albiventris was studied at various stages of development. Seventy-six specimens, with ages varying from 0 to 100 days, were used in this investigation. Serial sections of the maxilla were obtained in the transverse plane and stained with hematoxylin and eosin. Histological analyses were made to verify the pattern of teeth development, as well as their chronology of eruption. The period of time from birth to 100 days comprised the entire process of teeth development, from epithelial bud formation to early eruption of the teeth. Oral epithelium thickening gave rise to the functional incisors and canines. In addition, a secondary dental lamina emerged in different phases of development in the outer epithelium of incisors and canines, which degenerated when it reached the bud stage. No evidence of deciduous dentition was observed. The results of this investigation suggest that secondary dental lamina represents remnants of a primitive condition in which secondary dentition used to be present.

Orthodontic treatment of a patient with unerupted maxillary central and lateral incisors and canine: a case report.

PubMed

Sabuncuoğlu, Fidan Alakuş; Olmez, Hüseyin

2012-05-01

The aim of this case report was to describe the orthodontic and periodontal management of a patient with three impacted anterior teeth. An 18-year-old female with Class I crowding on a Class I skeletal base presented with the chief complaint of an unaesthetic smile. Clinical examination revealed an impacted upper right permanent canine (13), lateral (12) and central incisor (11), a retained deciduous incisor and moderate crowding in the lower arch. The impacted teeth were surgically exposed (closed exposure) and aligned with fixed appliances. The 12 was extracted due to root resorption and 44 extracted to resolve the lower arch crowding. A fraenectomy and gingival recontouring were required. Orthodontic treatment resulted in improved overjet, overbite and an acceptable facial profile. The patient reported improved self esteem. While impacted anterior teeth are a clinical challenge, their surgical exposure, in combination with fixed appliances, is a conservative treatment plan which is not without complications.

40 CFR 141.805 - Notification to passengers and crew.

Code of Federal Regulations, 2014 CFR

2014-07-01

... and should not be used for drinking, food or beverage preparation, hand washing, teeth brushing, or... beverage preparation, hand washing, teeth brushing, or any other consumptive use; (ii) A description of the... for drinking, food or beverage preparation, hand washing, teeth brushing, or any other consumptive use...

40 CFR 141.805 - Notification to passengers and crew.

Code of Federal Regulations, 2012 CFR

2012-07-01

... and should not be used for drinking, food or beverage preparation, hand washing, teeth brushing, or... beverage preparation, hand washing, teeth brushing, or any other consumptive use; (ii) A description of the... for drinking, food or beverage preparation, hand washing, teeth brushing, or any other consumptive use...

40 CFR 141.805 - Notification to passengers and crew.

Code of Federal Regulations, 2013 CFR

2013-07-01

... and should not be used for drinking, food or beverage preparation, hand washing, teeth brushing, or... beverage preparation, hand washing, teeth brushing, or any other consumptive use; (ii) A description of the... for drinking, food or beverage preparation, hand washing, teeth brushing, or any other consumptive use...

Localised enamel hypoplasia of human deciduous canines: genotype or environment?

PubMed

Taji, S; Hughes, T; Rogers, J; Townsend, G

2000-06-01

A discrete area of defective enamel formation that appears on the labial surface of the crowns of deciduous canine teeth has been described in both recent and prehistoric human populations, with reported frequencies varying from 1 to 45 per cent. Suggestions about the aetiology of this localized hypoplasia range from genotypic factors to environmental conditions and systemic effects. The major aims of this study were to describe the frequency of occurrence and pattern of expression of the lesion in Australian Aboriginal and Caucasian ethnic groups, and to clarify the role of genetic factors by examining a sample of twins. The study sample consisted of dental casts of 181 pairs of Australian Caucasian twins, 215 Aborigines and 122 Caucasian singletons, together with 253 extracted deciduous canines. Examination of dental casts and extracted teeth was undertaken under 2x magnification with emphasis being placed upon location and expression of the lesion. The defect was observed in 49 per cent of twins and 44 per cent of Aborigines, but only 36 per cent of singletons. The percentages of affected teeth in each group were: 18 per cent in twins, 17 per cent in Aborigines and 13 per cent in Caucasians. A significant proportion of the defects occurred on the mesial aspect of the labial surface, in the middle area incisocervically, with the majority in the lower jaw. A number of significant differences in frequency were observed between groups, sexes, arches and sides. The results confirm some of the findings of previous studies, but also suggest that none of environmental, genetic or systemic factors can be ruled out as being involved in aetiology of the defect. The higher incidence of the lesion occurring on the mesial aspect of the labial surface is suggestive of physical trauma. Also, the vulnerability of the prominent developing mandibular canine, with its thin or missing labial covering of bone, would be expected to lead to higher prevalence of the lesion in the lower jaw. Although not definitive, the results of concordance analyses in twins were suggestive of a possible genetic predisposition in the formation of the lesion. Further research with a greater clinical orientation and emphasis on determining specific aetiological factors within any given environment in different ethnic groups may provide better insight into the ambiguous aetiology of the hypoplastic enamel defect.

Comparative analysis of lignin peroxidase and manganese peroxidase activity on coniferous and deciduous wood using ToF-SIMS.

PubMed

MacDonald, Jacqueline; Goacher, Robyn E; Abou-Zaid, Mamdouh; Master, Emma R

2016-09-01

White-rot fungi are distinguished by their ability to efficiently degrade lignin via lignin-modifying type II peroxidases, including manganese peroxidase (MnP) and lignin peroxidase (LiP). In the present study, time-of flight secondary ion mass spectrometry (ToF-SIMS) was used to evaluate lignin modification in three coniferous and three deciduous wood preparations following treatment with commercial preparations of LiP and MnP from two different white-rot fungi. Percent modification of lignin was calculated as a loss of intact methoxylated lignin over nonfunctionalized aromatic rings, which is consistent with oxidative cleavage of methoxy moieties within the lignin structure. Exposure to MnP resulted in greater modification of lignin in coniferous compared to deciduous wood (28 vs. 18 % modification of lignin); and greater modification of G-lignin compared to S-lignin within the deciduous wood samples (21 vs. 12 %). In contrast, exposure to LiP resulted in similar percent modification of lignin in all wood samples (21 vs 22 %), and of G- and S-lignin within the deciduous wood (22 vs. 23 %). These findings suggest that the selected MnP and LiP may particularly benefit delignification of coniferous and deciduous wood, respectively. Moreover, the current analysis further demonstrates the utility of ToF-SIMS for characterizing enzymatic modification of lignin in wood fibre along with potential advantages over UV and HPCL-MS detection of solubilized delignification products.

[Comparison between lymphocytic infiltration in early spontaneous abortions and in elective abortions with signs of disruption at the chorio-decidual interface].

PubMed

Caliendo, L

2007-12-01

The aim of the study was to compare lymphocytic infiltrations in early spontaneous abortions with those with signs of disruption at the chorio-decidual interface in elective abortions. Determinations were performed on preparations received at the Anatomy-Pathology Services of Ospedale San Paolo, Savona (Italy) in 2005. Immunohistochemistry studies were performed using antisera CD3, CD4 and CD14 with a DAB detection kit on a Ventana BenchMark automated slide staining system. The material was grouped into three classes: early spontaneous abortions (class 1); elective abortions with signs of disruption at the chorio-decidual interface (class 2); elective abortions without such signs (class 3). Preparations from classes 1 and 2 shared a similar picture of lymphocytic activation and the presence of macrophagic elements. The test results demonstrated that the proportion of the T cell population increased with the rise in CD8+ lymphocytes in both class 1 and class 2 preparations. The results indicate that T-cell-mediated immune activation may the cause or one of the causes of spontaneous abortion and that the effects of disruption at the chorio-decidual interface observed in elective abortion provide a clue to initial signs of loss of pregnancy. From the discovery of a population without evident signs of active abortion (elective abortion with a disturbed chorio-decidual interface) but with evidence of initial lymphocytic activation compared with that devoid of such signs (elective abortion) one can conjecture that lymphocytic activation is a major factor in the process leading to early spontaneous abortion.

Indoleamine 2,3-Dioxygenase Is Dispensable for The Immunomodulatory Function of Stem Cells from Human Exfoliated Deciduous Teeth.

PubMed

Alipour, Razieh; Masoumi Karimi, Masoumeh; Hashemi-Beni, Batool; Adib, Minoo; Sereshki, Nasrin; Sadeghi, Farzaneh

2017-01-01

In this study, we sought to better understand the immunoregulatory function of stem cells derived from human exfoliated deciduous teeth (SHED). We studied the role of the interferon gamma (IFN-γ)-indoleamine 2,3-dioxygenase (IDO)-axis in immunoregulation of SHED compared to bone marrow derived mesenchymal stem cells (BMMSCs) under the same conditions. In this cross-sectional study, recently isolated human T cells were stimulated either by mitogen or inactivated allogeneic peripheral blood mononuclear cells (PBMCs). These T cells were subsequently co-cultured with, either SHED or BMMSCs in the presence or absence of 1-methyl-tryptophan (1-MT) or neutralizing anti- human-IFN-γ antibodies. In all co-cultures we evaluated lymphocyte activation as well as IDO activity. SHED, similar to conventional BMMSCs, had anti-proliferative effects on stimulated T cells and reduced their cytokine production. This property of SHED and BMMSCs was changed by IFN-γ neutralization. We detected IDO in the immunosuppressive supernatant of all co-cultures. Removal of IDO decreased the immunosuppression of BMMSCs. SHED, like BMMSCs, produced the IDO enzyme. Although IFN-γ is one of inducer of IDO production in SHED, these cells were not affected by IFN-γ in the same manner as BMMSCs. Unlike BMMSCs, the IDO enzyme did not contribute to their immunosuppression and might have other cell-type specific roles.

[Comparison of long-term dental treatment effects of children treated under general anesthesia and passive restraint].

PubMed

Zhou, F; Xia, B; Zhang, S; Ma, W L; Xiao, Y M; Ge, L H

2017-02-09

Objective: To compare the long-term dental treatment effects, oral health habits and oral-health-related qualities of life of children treated under general anesthesia (GA) and passive restraint (PR), respectively. Methods: Twenty seven 2 to 4-year-old children treated under GA and thirty four children treated under PR were recruited in the Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology. Up to 2 years after the treatment, a follow up assessment was conducted. The data of general information, dental plaque level and the unplanned treatments were recorded and analyzed. The questionnaire of oral health habits and early childhood oral health impact scale (ECOHIS) for each child was also completed and analyzed. The survival rate and median survival time of the deciduous teeth were calculated. Multivariate analysis was performed by using Cox proportional hazard model. Results: Twenty-five children under GA and 32 under PR were finally included, with a total of 1 098 deciduous teeth. The postoperative dental plaque indicesin both GA and PR groups had significantly improved than that of before the treatments ( P= 0.019, P< 0.001). The oral health habits had also improved, and the improvement in PR group was more obvious than that in GA group. Totally 128 teeth (27.0%) appeared unplanned treatments in GA group and 232 teeth (37.2%) in PR group during the follow-ups. The new caries and recurrent caries in PR group were significantly more than that in GA group ( P< 0.001, P= 0.012). No significant differences were found between the two groups in restoration failure, secondary caries and endodontic diseases ( P= 0.129, P= 0.822, P= 0.642). However, the time of occurrence of endodontic disease and secondary caries in GA group were significantly longer than that in PR group ( P< 0.01, P< 0.001). The median survival time of teeth in GA group was 1 018 days comparing to 944 days in PR group. The difference was statistically significant ( P< 0.05). The survival rate was associated with such factors as decayed-missing-filled tooth (dmft), anterior or posterior teeth, feeding frequency, brushing habits and behavior management techniques. Conclusions: The long-term dental treatment effects of children treated under GA was significantly better than that of PR group. Continuous reinforcement of proper dietary and oral hygiene habits might help in maintaining the long-term treatment effect.

Comparison of light-induced and laser-induced fluorescence methods for the detection and quantification of enamel demineralization

NASA Astrophysics Data System (ADS)

Ando, Masatoshi; Analoui, Mostafa; Schemehorn, Bruce R.; Stookey, George K.

1999-05-01

The Quantitative Laser-Induced Fluorescence (QLF) technique has been sued for diagnosis of early caries in permanent teeth (PT). The objective of this study was to determine the caries quantification ability of QLF in deciduous teeth (DT). Sixty sound teeth, thirty DT and thirty PT, were used. All teeth were cleaned to remove debris and equally divided into three groups. Lesions were created in small windows (0.8x2.0 mm2) on buccal or labial surface for 48, 72, and 96 hr. Lesion images were made with a 488 nm argon laser (QLF I) and then with a 370 +/- 80 nm violet-blue light (QLF II). Both images were analyzed to determine the mean percent change in fluorescence radiance (ΔF). A center section from the lesions was taken for analysis with microradiography. The lesion depth and loss of mineral content were determined. The correlations between ΔF and lesion depth as well as ΔZ in DT were 0.76 and 0.84 with QLF I, 0.81 and 0.88 with QLF II, respectively. It can be concluded the ability of QLF to quantify white-spots in DT is better than in PT.

Maxillary canine impactions related to impacted central incisors: two case reports.

PubMed

Bayram, Mehmet; Ozer, Mete; Sener, Ismail

2007-09-01

The purpose of this case report is to describe the combined surgical and orthodontic treatment of two cases with an impacted maxillary central incisor and canine in the same quadrant and to discuss the causal relationship between them. The most common causes of canine impactions are usually the result of one or more factors such as a long path of eruption, tooth size-arch length discrepancies, abnormal position of the tooth bud, prolonged retention or early loss of the deciduous canine, trauma, the presence of an alveolar cleft, ankylosis, cystic or neoplastic formation, dilaceration of the root, supernumerary teeth, and odontomas. Although impaction of the maxillary central incisor is almost as prevalent as impacted canines its etiology is different. The principal factors involved in causing the anomaly are supernumerary teeth, odontomas, and trauma. Case #1: A 10.5-year-old girl in the early mixed dentition stage presented with a chief complaint of the appearance of her anterior teeth. She had a Class I skeletal pattern and a history of trauma to the maxillary central incisors at age five with premature exfoliation. Radiographs revealed an impacted upper right central incisor in the region of the nasal floor, delayed eruption of the maxillary permanent central incisor, and the adjacent lateral incisor was inclined toward the edentulous space. Treatment was done in two stages consisting of surgical exposure and traction of the impacted central incisor and fixed orthodontic treatment. Case #2: An 11.5-year-old girl presented for orthodontic treatment with the chief complaint of an unerupted tooth and the appearance of her upper anterior teeth. She was in the late mixed dentition period with a Class III skeletal pattern along with an anterior cross-bite with some maxillary transverse deficiency. The maxillary right canine and central incisor were absent, but the maxillary right deciduous canine was still present. Treatment included arch expansion followed by surgical exposure and traction of the impacted teeth and fixed orthodontic treatment. This case report provides some evidence of a significant environmental influence of an impacted maxillary central incisor on the path of eruption of the ipsilateral maxillary canine. When an impacted maxillary central incisor exists, the maxillary lateral incisor's root might be positioned distally into the path of eruption of the maxillary canine preventing its normal eruption. Ongoing assessment and early intervention might help to prevent such adverse situations from occurring.

[Study on the appropriate parameters of automatic full crown tooth preparation for dental tooth preparation robot].

PubMed

Yuan, F S; Wang, Y; Zhang, Y P; Sun, Y C; Wang, D X; Lyu, P J

2017-05-09

Objective: To further study the most suitable parameters for automatic full crown preparation using oral clinical micro robot. Its purpose is to improve the quality of automated tooth preparing for the system and to lay the foundation for clinical application. Methods: Twenty selected artificial resin teeth were used as sample teeth. The micro robot automatic tooth preparation system was used in dental clinic to control the picosecond laser beam to complete two dimensional cutting on the resin tooth sample according to the motion planning path. Using the laser scanning measuring microscope, each layer of cutting depth values was obtained and the average value was calculated. The monolayer cutting depth was determined. The three-dimensional (3D) data of the target resin teeth was obtained using internal scanner, and the CAD data of full-crown tooth preparation was designed by CAD self-develged software. According to the depth of the single layer, 11 complete resin teeth in phantom head were automatically prepared by the robot controlling the laser focused spot in accordance with the layer-cutting way. And the accuracy of resin tooth preparation was evaluated with the software. Using the same method, monolayer cutting depth parameter for cutting dental hard tissue was obtained. Then 15 extracted mandibular and maxillary first molars went through automatic full crown tooth preparation. And the 3D data of tooth preparations were obtained with intra oral scanner. The software was used to evaluate the accuracy of tooth preparation. Results: The results indicated that the single cutting depth of cutting resin teeth and in vitro teeth by picosecond laser were (60.0±2.6) and (45.0±3.6) μm, respectively. Using the tooth preparation robot, 11 artificial resin teeth and 15 complete natural teeth were automatically prepared, and the average time were (13.0±0.7), (17.0±1.8) min respectively. Through software evaluation, the average preparation depth of the occlusal surface of 11 resin teeth was approximately (2.089±0.026) mm, the error was about (0.089±0.026) mm; the average convergence angle was about 6.56°±0.30°, the error was about 0.56°±0.30°. Compared with the target preparation shape, the average shape error of the 11 resin tooth preparations was about 0.02-0.11 mm. And the average preparation depth of the occlusal surface of 15 natural teeth was approximately (2.097±0.022) mm, the error was about (0.097±0.022) mm; the average convergence angle was about 6.98°±0.35°, the error was about 0.98°±0.35°. Compared with the target preparation shape, the average shape error of the 15 natural tooth preparations was about 0.05-0.17 mm. Conclusions: The experimental results indicate that the automatic tooth preparation for resin teeth and the teeth were completed according to the specific parameters of the single cutting depth by the micro robot controlling picosecond laser respectively, its preparation accuracy met the clinical needs. And the suitability of the parameter was confirmed.

Changes in deciduous and permanent dentinal tubules diameter after several conditioning protocols: In vitro study.

PubMed

de Los Angeles Moyaho-Bernal, María; Contreras-Bulnes, Rosalía; Rodríguez-Vilchis, Laura Emma; Rubio-Rosas, Efraín

2018-05-08

Innovators conditioning protocols are emerged in permanent dentin, however for deciduous dentin the information is limited; the aim of this study was to evaluate in vitro diameter of deciduous and permanent dentinal tubules after several conditioning protocols. Eighty dentin samples were distributed in sixteen groups (n = 5 p/g) and dentin surface was conditioned as follow: G1D/G1P acid etching; G2D/G2P, self-etch adhesive; G3D/G3P, G4D/G4P, Er: YAG laser irradiation at 200 mJ-25.5 J/cm 2 and 300 mJ-38.2 J/cm 2 , at 10 Hz under water spray respectively; G5D/G5P, G6D/G6P, G7D/G7P, and G8D/G8P were irradiated under the same energy densities followed phosphoric acid or self-etch adhesive conditioning. The sample dentin of deciduous and permanent teeth was analyzed with scanning electron microscopy and tubule diameter was evaluated by Image Tools Scandium program. Data were subjected to one-way analysis ANOVA to compare among groups with a level of significance at p ≤ .05. For deciduous dentin, diameters were from 1.52 ± 0.32 µm in G3D to 3.88 ± 0.37 µm in G1D; narrowest and widest diameter, respectively (p < .000). While permanent dentin tubules exhibited diameters from 1.16 ± 0.16/1.19 ± 0.12 µm in G7P/G8P to 2.76 ± 0.28 µm in G6P; narrowest and widest diameter, respectively (p < .000). All dentin conditioning protocols produced more open dentin tubules (diameter size) in deciduous dentin than permanent, specific conditioning protocols are required for each tissue (deciduous or permanent dentin), since same protocol produced stronger effects on primary dentin, which is important for dental clinical success in children and adolescents. © 2018 Wiley Periodicals, Inc.

Lead contents in the surface enamel of deciduous teeth sampled in vivo from children in uncontaminated and in lead-contaminated areas

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

Almeida, Glauce Regina Costa de; Pereira Saraiva, Maria da Conceicao; Barbosa Jr, Fernando

2007-07-15

This study aimed to: (1) measure lead contents in the surface enamel of two populations consisting of 4-6-year-old children, one from an apparently uncontaminated area (Ribeirao Preto, Sao Paulo State, SP, Brazil, n=247) and the other from an area notoriously contaminated with lead (Bauru, Sao Paulo State, Brazil, n=26); (2) compare biopsy depths between the two populations; (3) correlate biopsy depth with lead content; (4) stratify samples according to biopsy depth to compare lead contents in samples from similar biopsy depths. A surface enamel acid-etch microbiopsy was performed in vivo on a single upper deciduous incisor for each sample. Leadmore » was measured by graphite furnace atomic absorption spectrometry (GFAAS) while phosphorus was measured colorimetrically to establish biopsy depth. Samples from both populations were classified into categories of similar biopsy depths based on biopsy depth quartiles. Median lead contents were statistically different between the Ribeirao Preto population (206 {mu}g/g, range: 5-1399 {mu}g/g) and the Bauru population (786 {mu}g/g, range: 320-4711 {mu}g/g) (p<0.001); however, biopsy depth did not differ between the Ribeirao Preto (3.9 {mu}m, Standard Deviation, SD=0.9) and Bauru (3.8 {mu}m, SD=0.9) populations (p=0.7940). Pearson's correlation coefficient for biopsy depths versus log{sub 10} lead values was -0.29 for Ribeirao Preto and -0.18 for Bauru. Lead contents were statistically different between the two populations for all quartiles of biopsy depth. These findings suggest that lead accumulated in the surface enamel of deciduous teeth is linked to the environment in which people reside, indicating that this tissue should be further explored as an accessible biomarker of lead exposure.« less

Neonatal line width in deciduous incisors from Neolithic, mediaeval and modern skeletal samples from north-central Poland.

PubMed

Kurek, Marta; Żądzińska, Elżbieta; Sitek, Aneta; Borowska-Strugińska, Beata; Rosset, Iwona; Lorkiewicz, Wiesław

2016-01-01

The neonatal line is usually the first accentuated incremental line visible on the enamel. The prenatal environment significantly contributes to the width of the neonatal line, influencing the pace of reaching post-delivery homeostasis by the newborn's organism. Studies of the enamel of the earliest developing deciduous teeth can provide an insight into the prenatal development and the perinatal conditions of children of past human populations, thus being an additional source contributing to consideration of the influence of prenatal and perinatal factors modifying growth processes. The aim of this study was to examine whether the neonatal line, reflecting the conditions of the prenatal and perinatal environment, differed between the Neolithic, the mediaeval and the modern populations from the Kujawy region in north-central Poland. The material consisted of longitudinally ground sections of 57 human deciduous incisors obtained from children aged 1.0-7.5 years representing three archaeological series from Brześć Kujawski site. All teeth were sectioned in the labio-linqual plane using a diamond blade (Buechler IsoMet 1000). Final specimens were observed with the microscope Delta Optical Evolution 300 at 10× and 40× magnifications. For each tooth, linear measurements of the neonatal line width were performed on its labial surface at the three levels from the cemento-enamel junction. No significant difference was found in the mean neonatal line width depending on the tooth type and archaeological site, although the thickest neonatal line characterised children from the Neolithic series. In all analysed series, the neonatal line width was diversified depending on the child's age at death. The value of Spearman's rank correlation coefficient calculated for the correlation between the child's age at death and the neonatal line width was statistically significant. A clear increase in the width of the neonatal line was thus observed along with a decrease in the child's age at death. Copyright © 2015 Elsevier GmbH. All rights reserved.

The determination of antibody to Streptococcus mutans serotypes in saliva for children ages 3 to 7 years.

PubMed

Everhart, D L; Rothenberg, K; Carter, W H; Klapper, B

1978-04-01

The saliva of 29 children ages 3 to 7 years was followed by indirect immunoflourescence to determine the antibody reacting with the 5 different serotypes of S mutans. Fluorescent antisera specific for alpha chain and gamma chain were used. Statistical analysis of the data demonstrated a significant negative correlation between antibody of immunoglobin class (IgA) to S mutans type b and the decayed, extracted and filled surfaces of deciduous teeth.

A Comparison of Arch Width with Angle Classification and Wits Appraisal in Class 2 Division 1 and Class 1 Individuals.

DTIC Science & Technology

1983-05-01

longitudinal changes in arch width between lateral incisors, canines and second premolars or deciduous second molars at four stages of dental eruption in 22 male... dental arch or skeletal widths. Also, he made no attempt to divide his sample into normal and malocclusion groups. -J 7 Warren (1959) studying twenty...buccal crossbite of the posterior teeth Many clinicians believe that this problem is highly correlated with tfte type or classification of malocclusion

Rotary Mtwo system versus manual K-file instruments: efficacy in preparing primary and permanent molar root canals.

PubMed

Azar, Mohammad-Reza; Mokhtare, Maziar

2011-01-01

To compare the cleaning ability and preparation time of rotary instruments (Mtwo) and conventional manual instruments (K-file) in preparing primary and permanent molar root canals. Access cavities were prepared in 70 primary and 70 permanent teeth and India ink was injected into 120 canals of selected molars. The teeth were randomly divided into two main subgroups (n=20) and three control groups (n=10). In each of these main subgroups, either the manual instrument (K-file) or the rotary system (Mtwo) was used to prepare root canals. After cleaning the canals and clearing the teeth, dye removal was evaluated with the help of a stereomicroscope. In addition, the time needed for root canal preparation was recorded by a chronometer. Statistical analyses were done using the Kruskal-Wallis, Mann-Whitney and t tests. With regard to the cleaning ability of root canals, there were no significant differences between the K-file and Mtwo rotary system in primary and permanent teeth in the apical, middle or coronal third of the canals. Moreover, there were no significant differences between primary and permanent teeth prepared with K-files and rotary instruments. In all the groups, shorter times were recorded with the rotary technique. The working time was shorter in primary than in permanent teeth. The Mtwo rotary system showed acceptable cleaning ability in both primary and permanent teeth, and achieved results similar to those of K-files in less time.

Attitude and beliefs of some nurses in government hospitals in Ibadan, Nigeria to natal/neonatal teeth in infants.

PubMed

Bankole, O O; Oke, G A

2013-09-01

Eruption of the first deciduous teeth in children has shown much variation and occasionally may erupt prematurely at birth or within one month of life. Myths about natal/neonatal teeth abound in the Nigerian culture. Nurses are health care providers who are in constant close contact with patients and can be invaluable in helping to dispel these associated myths. However, to provide correct information they should be adequately equipped to do so. The aim of this study thus, was to assess the attitudes and beliefs of some nurses in Ibadan, Nigeria to natal/neonatal teeth in infants. A cross sectional survey was conducted among 380 nurses in the teaching, general and local government hospitals and clinics in Ibadan, Nigeria. Results revealed that 41.3% of the respondents would express shock and surprise if they assisted in delivering a baby with natal teeth. Half of the respondents (49.7%) felt that natal/neonatal teeth will be a great source of embarrassment to the family while a smaller proportion (11.8%), believed it was a curse (p = 0.01). On the advice the respondents would give to the mothers, more than a th (39.7%), would recommend immediate extraction of the teeth. A further 42 (11.1%) nurses were of the opinion that spiritual cleansing should be carried out prior to extraction. A greater proportion of the older nurses would advice immediate extraction of the teeth (p = 0.031). Regarding the perceived effect of natal/neonatal teeth on the children, (7.4%), (12.6%) and (29.2%) of the respondents believed that the children will behave strangely, will possess spiritual authority and be victims of stigmatization later in life respectively. This study has revealed that knowledge gaps about natal/neonatal teeth exist among the nurses in Ibadan, Nigeria. Health education programmes targeted at nurses are essential to correct these beliefs.

Dental enamel defects in Italian children with cystic fibrosis: an observational study.

PubMed

Ferrazzano, G F; Sangianantoni, G; Cantile, T; Amato, I; Orlando, S; Ingenito, A

2012-03-01

The relationship between cystic fibrosis (CF) and caries experience has already been explored, but relatively little information is available on dental enamel defects prevalence among children affected by cystic fibrosis. The aim of this study was to investigate this issue in deciduous and permanent teeth of children with CF resident in southern Italy. This cross sectional observational study was undertaken between October 2009 and March 2010. 88 CF patients and 101 healthy age-matched participated in this study. The prevalence of dental enamel defects was calculated using a modified Developmental Defects of Enamel (DDE) index. The comparison of dental enamel defects prevalence among groups was carried out using regression binary logistic analysis. In the CF subjects there was a higher prevalence (56%) of enamel defects in comparison to the healthy group (22%). The most prevalent enamel defect was hypoplasia with loss of enamel (23% of CF patients vs 1 1/2% of control group) in permanent teeth. This study confirms that children with cystic fibrosis are at increased risk of developing hypoplastic defects on their permanent teeth.

Trends in caries experience and associated contextual factors among indigenous children.

PubMed

Ha, Diep Hong; Lalloo, Ratilal; Jamieson, Lisa M; Giang Do, Loc

2016-06-01

To assess dental caries trends in indigenous children in South Australia, 2001-2010; and contribution by area-level socioeconomic status (SES), remoteness and water fluoridation status. This study is a part of the Child Dental Health Survey (CDHS) is an ongoing national surveillance survey in Australia including children enrolled in the School Dental Services (SDS). Postcode-level adjusted mean deciduous and permanent caries experience was estimated at each year. Time trend of dental caries experience was estimated using mixed effect models. Area-level socioeconomic status, remoteness, water fluoridation status were independent variables in the models. There was a significant upward trend of dental caries experience over the 10 years. Dental caries experience of indigenous children living in low SES areas had nearly one more deciduous tooth and a half permanent tooth with caries than indigenous children living in higher SES areas. The remote postcodes showed higher levels of decay in deciduous dentition (+1.25 teeth) compared with others regions. The dental caries trend increased in South Australian indigenous children over the study period, and was associated with area-level SES and remoteness. The increasing trend in dental caries in indigenous children is important evidence to inform policies to improve oral health. © 2015 American Association of Public Health Dentistry.

[An in vitro study of the fracture strength of tooth preparations for Empress 2 veneers and crowns and mandibular incisors restored with Empress 2 veneers and crowns].

PubMed

Wei, Xue; Li, Yan

2009-12-01

To compare the fracture resistance of mandibular incisors' preparations for veneers and crowns, mandibular incisors restored with Empress 2 veneers and crowns. 50 human mandibular incisors were randomly divided into five groups. Each group consisted of ten teeth and the treatment obtained as follows: A, tooth preparations for veneers; B, tooth preparations for crowns; C, teeth restored with veneers; D, teeth restored with crowns; E, untreated group. The teeth received standardized preparation and the restorations were manufactured with Empress 2 system and cemented with resin luting agent. The fracture resistances of teeth were measured by Instron universal testing machine and statistically analyzed with one-way ANOVA. The fracture resistances of A, B, C, D, E were (576.11 +/- 91.53), (204.13 +/- 85.88), (451.50 +/- 116.81), (386.16 +/- 117.75) and (566.05 +/- 121.37) N, respectively. The statistical analysis demonstrated significant differences between five groups. There were no significant differences between group A and E, group C and D. Tooth preparations for veneers did not significantly reduce the fracture resistance of mandibular incisor. The fracture resistance of teeth restored with Empress 2 veneers and crowns did not significantly differ from each other.

Reciprocating vs Rotary Instrumentation in Pediatric Endodontics: Cone Beam Computed Tomographic Analysis of Deciduous Root Canals using Two Single-file Systems.

PubMed

Prabhakar, Attiguppe R; Yavagal, Chandrashekar; Dixit, Kratika; Naik, Saraswathi V

2016-01-01

Primary root canals are considered to be most challenging due to their complex anatomy. "Wave one" and "one shape" are single-file systems with reciprocating and rotary motion respectively. The aim of this study was to evaluate and compare dentin thickness, centering ability, canal transportation, and instrumentation time of wave one and one shape files in primary root canals using a cone beam computed tomographic (CBCT) analysis. This is an experimental, in vitro study comparing the two groups. A total of 24 extracted human primary teeth with minimum 7 mm root length were included in the study. Cone beam computed tomographic images were taken before and after the instrumentation for each group. Dentin thickness, centering ability, canal transportation, and instrumentation times were evaluated for each group. A significant difference was found in instrumentation time and canal transportation measures between the two groups. Wave one showed less canal transportation as compared with one shape, and the mean instrumentation time of wave one was significantly less than one shape. Reciprocating single-file systems was found to be faster with much less procedural errors and can hence be recommended for shaping the root canals of primary teeth. How to cite this article: Prabhakar AR, Yavagal C, Dixit K, Naik SV. Reciprocating vs Rotary Instrumentation in Pediatric Endodontics: Cone Beam Computed Tomographic Analysis of Deciduous Root Canals using Two Single-File Systems. Int J Clin Pediatr Dent 2016;9(1):45-49.

Effects of mineral trioxide aggregate, BiodentineTM and calcium hydroxide on viability, proliferation, migration and differentiation of stem cells from human exfoliated deciduous teeth.

PubMed

Araújo, Leandro Borges; Cosme-Silva, Leopoldo; Fernandes, Ana Paula; Oliveira, Thais Marchini de; Cavalcanti, Bruno das Neves; Gomes Filho, João Eduardo; Sakai, Vivien Thiemy

2018-02-01

The aim of the study was to evaluate the effects of the capping materials mineral trioxide aggregate (MTA), calcium hydroxide (CH) and BiodentineTM (BD) on stem cells from human exfoliated deciduous teeth (SHED) in vitro. SHED were cultured for 1 - 7 days in medium conditioned by incubation with MTA, BD or CH (1 mg/mL), and tested for viability (MTT assay) and proliferation (SRB assay). Also, the migration of serum-starved SHED towards conditioned media was assayed in companion plates, with 8 μm-pore-sized membranes, for 24 h. Gene expression of dentin matrix protein-1 (DMP-1) was evaluated by reverse-transcription polymerase chain reaction. Regular culture medium with 10% FBS (without conditioning) and culture medium supplemented with 20% FBS were used as controls. MTA, CH and BD conditioned media maintained cell viability and allowed continuous SHED proliferation, with CH conditioned medium causing the highest positive effect on proliferation at the end of the treatment period (compared with BD and MTA) (p<0.05). In contrast, we observed increased SHED migration towards BD and MTA conditioned media (compared with CH) (p<0.05). A greater amount of DMP-1 gene was expressed in MTA group compared with the other groups from day 7 up to day 21. Our results show that the three capping materials are biocompatible, maintain viability and stimulate proliferation, migration and differentiation in a key dental stem cell population.

Stem cells from human exfoliated deciduous teeth differentiate toward neural cells in a medium dynamically cultured with Schwann cells in a series of polydimethylsiloxanes scaffolds

NASA Astrophysics Data System (ADS)

Su, Wen-Ta; Pan, Yu-Jing

2016-08-01

Objective. Schwann cells (SCs) are primary structural and functional cells in the peripheral nervous system. These cells play a crucial role in peripheral nerve regeneration by releasing neurotrophic factors. This study evaluated the neural differentiation potential effects of stem cells from human exfoliated deciduous teeth (SHEDs) in a rat Schwann cell (RSC) culture medium. Approach. SHEDs and RSCs were individually cultured on a polydimethylsiloxane (PDMS) scaffold, and the effects of the RSC medium on the SHEDs differentiation between static and dynamic cultures were compared. Main results. Results demonstrated that the SHED cells differentiated by the RSC cultured medium in the static culture formed neurospheres after 7 days at the earliest, and SHED cells formed neurospheres within 3 days in the dynamic culture. These results confirm that the RSC culture medium can induce neurospheres formation, the speed of formation and the number of neurospheres (19.16 folds high) in a dynamic culture was superior to the static culture for 3 days culture. The SHED-derived spheres were further incubated in the RSCs culture medium, these neurospheres continuously differentiated into neurons and neuroglial cells. Immunofluorescent staining and RT-PCR revealed nestin, β-III tubulin, GFAP, and γ-enolase of neural markers on the differentiated cells. Significance. These results indicated that the RSC culture medium can induce the neural differentiation of SHED cells, and can be used as a new therapeutic tool to repair nerve damage.

Bilateral cross-bite treated by repeated rapid maxillary expansions: a 17-year follow-up case.

PubMed

Cozzani, M; Mazzotta, L; Caprioglio, A

2014-07-01

The objective of this paper is to show the clinical results after the repeated application of a Haas expander for rapid maxillary expansion (RME) anchored onto deciduous teeth in a 7-year-old patient that presented bilateral cross-bite, superior crowding and no space for permanent lateral incisors eruption. A first Haas expander was applied to the patient. She was told to activate it once a day, each activation was equal to 0.20 mm. After the first RME, the bilateral cross-bite was solved but still there was not enough space for lateral incisor eruption. A second and then a third Haas expander were applied, with the same activation protocol as the first one, in order to gain space in the anterior region and to achieve proper eruption of the lateral incisors. The patient was then treated with fixed appliances. At debonding the patient presented well aligned arch-forms: space for lateral incisor eruption was gained and superior crowding was solved. Bilateral cross-bite was also corrected. She was seen again 10 years and 17 years after expansions: she showed no relapse and presented a good functional occlusion that had remained stable, and an aesthetically pleasant smile, however she exhibited gingival recessions. Repeated rapid maxillary expansion, anchored onto deciduous teeth, performed in early mixed dentition represents a safe and successful treatment to correct severe bilateral cross- bites and to create space for maxillary incisor eruption.

The effect of stem cell from human exfoliated deciduous teeth on T lymphocyte proliferation.

PubMed

Alipour, Razieh; Adib, Minoo; Hashemi-Beni, Batool; Sadeghi, Farzaneh

2014-01-01

Mesenchymal stem cells (MSC), a specific type of adult tissue stem cell; have the immunosuppressive effects that make them valuable targets for regenerative medicine and treatment of many human illnesses. Hence, MSC have been the subject of numerous studies. The classical source of MSC is adult bone marrow (BM). Due to many shortcomings of harvesting MSC from BM, finding the alternative sources for MSC is an urgent. Stem cells from human exfoliated deciduous teeth (SHED) are relative new MSC populations that fulfill these criteria but their potential immunosuppressive effect has not been studied enough yet. Thus, in this work the effect of SHED on the proliferation of in vitro activated T lymphocytes were explored. In this study, both mitogen and alloantigen activated T cells were cultured in the presence of different numbers of SHED. In some co-cultures, activated T cells were in direct contact to MSCs and in other co-cultures; they were separated from SHED by a permeable membrane. In all co-cultures, the proliferation of T cells was measured by ELISA Bromodeoxyuridine proliferation assay. In general, our results showed that SHED significantly suppress the proliferation of activated T cells in a dose-dependent manner. Moreover, the suppression was slightly stronger when MSCs were in physical contact to activated T cells. This study showed that SHED likewise other MSC populations can suppress the activation of T lymphocytes, which can be used instead of BM derived MSCs in many investigational and clinical applications.

[The dynamics of blood circulation in marginal gingiva after crown preparation by different ledge locations].

PubMed

Shcherbakov, A S; Kuznetsova, M B; Kuznetsov, D L; Ivanova, S B

2013-01-01

The periodontal tissue level may change after gingival margin retraction and tooth preparation. The aim of the study was to assess the influence of these manipulations on the condition of free gingival margin. The study included 53 persons (29 women and 24 men) divided into 4 groups followed-up for 6 to 8 weeks. Blood circulation in marginal gingiva of 118 teeth with healthy periodontal tissues was assessed by ultrasonic Doppler evaluation to reveal the circulation impairments in cervical margin after teeth crown preparation. The first group included 39 teeth, in which the gum was retracted by Roeko stay put non impregna cords ("Langenau", Germany). The second group included 39 teeth with shoulders prepared at the gingival margin; in the third group (40 teeth) the shoulder was located subgingivally. The fourth group (40 teeth) was control. The changes in recovery indices have been analyzed. The linear values were established as most significant and demonstrative. The indices variations and recovery period length depended on the coronal edge location. Statistically significant differences were found among all the groups (p>0.05). The results may be used to improve crown preparation for fixed dentures and decrease the recession rate of free gingival margin.

Prevalence of hypodontia in nine- to fourteen-year-old children who attended the Mashhad School of Dentistry.

PubMed

Ajami, Behgat-al-molok; Shabzendedar, Mahboobeh; Mehrjerdian, Maryam

2010-01-01

Hypodontia is defined as the congenital absence of one or a few teeth, and is also the most common anomaly in dental development. This condition occurs either individually or as part of the symptoms of a syndrome, and it is more common in permanent teeth than in deciduous teeth, reporting a prevalence of between 1.6 and 9.6%. The objective of this study is to investigate the prevalence of hypodontia for permanent teeth in nine- to 14-year-old children who attended the Mashhad School of Dentistry in 2007. We conducted this descriptive, analytical, cross-sectional study, to determine the mentioned aims. In this descriptive, cross-sectional study, panoramic radiographs belonging to 600 children (351 girls and 249 boys), aged nine to 14 years, were available for examination. All related findings were recorded in the respective forms. The data were processed using Exact and Chi-square tests. The prevalence of hypodontia in the girls was 9.2%, in the boys 8.8%, and in both sexes combined 9%. The most and the least frequent cases of absent teeth were the mandibular second premolars and the maxillary central incisor (only one child), respectively. The most commonly absent teeth were the mandibular second premolars, the maxillary lateral incisors, the mandibular central incisor, and the maxillary second premolars, in that order. This study showed a high frequency of hypodontia among the understudied population. Thus, due to the complicated treatment, accurate examination of children for on-time diagnosis of this developmental anomaly is crucial.

Regenerative medicine using dental pulp stem cells for liver diseases.

PubMed

Ohkoshi, Shogo; Hara, Hajime; Hirono, Haruka; Watanabe, Kazuhiko; Hasegawa, Katsuhiko

2017-02-06

Acute liver failure is a refractory disease and its prognosis, if not treated using liver transplantation, is extremely poor. It is a good candidate for regenerative medicine, where stem cell-based therapies play a central role. Mesenchymal stem cells (MSCs) are known to differentiate into multiple cell lineages including hepatocytes. Autologous cell transplant without any foreign gene induction is feasible using MSCs, thereby avoiding possible risks of tumorigenesis and immune rejection. Dental pulp also contains an MSC population that differentiates into hepatocytes. A point worthy of special mention is that dental pulp can be obtained from deciduous teeth during childhood and can be subsequently harvested when necessary after deposition in a tooth bank. MSCs have not only a regenerative capacity but also act in an anti-inflammatory manner via paracrine mechanisms. Promising efficacies and difficulties with the use of MSC derived from teeth are summarized in this review.

Human dental pulp stem cells with highly angiogenic and neurogenic potential for possible use in pulp regeneration.

PubMed

Nakashima, Misako; Iohara, Koichiro; Sugiyama, Masahiko

2009-01-01

Dental caries is a common public health problem, causing early loss of dental pulp and resultant tooth loss. Dental pulp has important functions to sustain teeth providing nutrient and oxygen supply, innervation, reactionary/reparative dentin formation and immune response. Regeneration of pulp is an unmet need in endodontic therapy, and angiogenesis/vasculogenesis and neurogenesis are critical for pulp regeneration. Permanent and deciduous pulp tissue is easily available from teeth after extraction without ethical issues and has potential for clinical use. In this review, we introduce some stem cell subfractions, CD31(-)/CD146(-) SP cells and CD105(+) cells with high angiogenic and neurogenic potential, derived from human adult dental pulp tissue. Potential utility of these cells is addressed as a source of cells for treatment of cerebral and limb ischemia and pulp inflammation complete with angiogenesis and vasculogenesis.

Open reduction and internal fixation of mandibular fracture in an 11-month-old infant: a case report

PubMed Central

Kim, Tae-Wan; Seo, Eun-Woo

2013-01-01

Mandibular fractures in infants are rare. This case report describes management of a mandibular fracture in an 11-month-old infant using a microplate and screws with open reduction. The surgical treatment was successful. Because the bone fragments were displaced and only the primary incisors had erupted, conservative treatment, such as an acrylic splint and circummandibular wiring, was not recommended. Nine weeks after surgery, the microplate was removed. The results showed complete clinical and radiological bone healing with normal eruption of deciduous teeth. PMID:24471024

Topography and presence of a smear layer in deciduous molars prepared with high-speed cutting and ultrasonic abrasion: an in-vitro study.

PubMed

Vieira, Áurea Simone Barroso; Pedro, Rafael de Lima; Antunes, Leonardo Dos Santos; Alves Dos Santos, Márcia Pereira; Antunes, Livia Azeredo Alves; Primo, Laura Guimarães; Maia, Lucianne Cople

2011-05-01

The aim of this in-vitro study was to compare the effect of high-speed cutting (HS) with ultrasonic abrasion (US) concerning the internal topography and the presence of a smear layer in a cavity preparation performed in healthy deciduous molars. Seven first deciduous molars were used. Two occlusal cavity preparation were done, one in the medial fossula and another in the distal fossula, which were chosen randomly. One preparation was carried out with a diamond point adapted to the HS system (GI), while a chemical vapor deposition (CVD) point adapted to a US device (GII) was used for the other preparation. Subsequently, all samples (n = 14) were cleaved to observe the inside and then prepared for evaluation using scanning electron photomicroscopy. The internal topography of the prepared cavities was descriptively analyzed. In order to assess the presence of a smear layer, scores were tabulated using the 2000 GMC program and analyzed using the Mann-Whitney test. Concerning the internal topography, the presence of striae was verified in both groups. In the GI group they were finer, found in a greater number, and with narrower spaces between them. In the GII group, the striae were undulating, similar to the effect of wheels on sand, and with wider spaces between them. As regards the presence of a smear layer, there was no statistically significant difference between the groups (P > 0.05). In view of the methodology employed, it may be concluded that cavity preparation with a CVD point in a US abrasion system led to the formation of fewer striae and both devices promoted the marked presence of a smear layer, obstructing dentinal tubuli.

Correlation of CD4 count with cariogenic oral flora indicators and dental caries in HIV-seropositive children undergoing antiretroviral therapy in Mangaluru, South India.

PubMed

Muraleedharan, Soumya; Panchmal, Ganesh Shenoy; Shenoy, Rekha P; Jodalli, Praveen; Sonde, Laxminarayan; Pasha, Imran

2018-05-01

The aim of the present study was to compare the association of CD4 count with cariogenic oral flora indicators and dental caries in HIV-seropositive children receiving antiretroviral therapy (ART). A descriptive study was conducted among HIV-seropositive children receiving ART at Snehasadan Camillian Care and Support Center HIV/AIDS in Mangaluru, India. Demographic details and r recent CD4 counts were recorded. For dental caries, the Decayed, Missing, Filled Teeth (DMFT)/decayed, missing, filled/decayed, extracted, filled index was used. Data were analyzed using SPSS version 22. Spearman's correlation was used to correlate CD4 count with dental caries and cariogenic oral flora indicators (mutans streptococci and lactobacilli). The study population comprised 35 patients. Dental caries prevalence was 54.1% in deciduous teeth and 41.2% in permanent teeth. Age and DMFT showed a significant, positive correlation; age and dmft showed a negative correlation (P < .05). A weak, negative correlation was found between age and Streptococcus mutans (S. mutans), and also CD4 count; S. mutans and CD4 count and dmft were not found to be statistically significant (P < .05). No statistically-significant correlation was found between CD4 count and cariogenic oral flora indicators in HIV-positive patients. The presence of a minimum number of restored teeth compared to decayed teeth suggests a lack of dental care being given to HIV-positive patients. © 2017 John Wiley & Sons Australia, Ltd.

High-contrast x-ray microtomography in dental research

NASA Astrophysics Data System (ADS)

Davis, Graham; Mills, David

2017-09-01

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

Fracture Strength of Endodontically Treated Teeth with Different Access Cavity Designs.

PubMed

Plotino, Gianluca; Grande, Nicola Maria; Isufi, Almira; Ioppolo, Pietro; Pedullà, Eugenio; Bedini, Rossella; Gambarini, Gianluca; Testarelli, Luca

2017-06-01

The purpose of this study was to compare in vitro the fracture strength of root-filled and restored teeth with traditional endodontic cavity (TEC), conservative endodontic cavity (CEC), or ultraconservative "ninja" endodontic cavity (NEC) access. Extracted human intact maxillary and mandibular premolars and molars were selected and assigned to control (intact teeth), TEC, CEC, or NEC groups (n = 10/group/type). Teeth in the TEC group were prepared following the principles of traditional endodontic cavities. Minimal CECs and NECs were plotted on cone-beam computed tomographic images. Then, teeth were endodontically treated and restored. The 160 specimens were then loaded to fracture in a mechanical material testing machine (LR30 K; Lloyd Instruments Ltd, Fareham, UK). The maximum load at fracture and fracture pattern (restorable or unrestorable) were recorded. Fracture loads were compared statistically, and the data were examined with analysis of variance and the Student-Newman-Keuls test for multiple comparisons. The mean load at fracture for TEC was significantly lower than the one for the CEC, NEC, and control groups for all types of teeth (P < .05), whereas no difference was observed among CEC, NEC, and intact teeth (P > .05). Unrestorable fractures were significantly more frequent in the TEC, CEC, and NEC groups than in the control group in each tooth type (P < .05). Teeth with TEC access showed lower fracture strength than the ones prepared with CEC or NEC. Ultraconservative "ninja" endodontic cavity access did not increase the fracture strength of teeth compared with the ones prepared with CEC. Intact teeth showed more restorable fractures than all the prepared ones. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Dental and Temporomandibular Joint Pathology of the American Black Bear (Ursus americanus).

PubMed

Clark, E J; Chesnutt, S R; Winer, J N; Kass, P H; Verstraete, F J M

Museum specimens (maxillae and/or mandibles) from 371 American black bears (Ursus americanus) acquired between 1889 and 2006 were examined macroscopically according to predefined criteria, and 348 were included in this study. Of the 348 specimens, 126 (36.2%) were from male animals, 106 (30.5%) were from female animals and 116 (33.3%) were from animals of unknown sex. Specimen ages ranged from young adult (n = 63, 18.1%) to adult (n = 285, 81.9%), with juveniles excluded from the study. The number of teeth available for examination was 12,019 (82.2%); 7.0% of teeth were absent artefactually, 0.4% were deemed absent due to acquired tooth loss and 9.7% were absent congenitally. In 43 specimens (12.3%), 82 teeth (0.68%) were small vestigial structures with crowns that were flush with the level of surrounding alveolar bone. The remaining teeth (99.3%) were of normal morphology. Only three supernumerary teeth and three instances of enamel hypoplasia were encountered. Persistent deciduous teeth or teeth with an aberrant number of roots were not encountered in any of the specimens. Approximately one-third of the teeth examined (4,543, 37.8%) displayed attrition/abrasion, affecting nearly all of the specimens (n = 338, 97.1%). Incisor and molar teeth accounted for 52.5% and 34.3% of the affected teeth, respectively, with significantly more adults affected than young adults. Dental fractures were noted in 63 bears, affecting 18.1% of specimens and 1.0% of the total number of present teeth. The canine teeth were most often fractured, with adults having significantly more complicated crown fractures of these teeth than young adults. There were 11 specimens (3.2%) that displayed periapical lesions, affecting 12 (0.1%) dental alveoli. There were 179 specimens (51.4%) displaying bony changes indicative of periodontitis, affecting 816 (6.8%) dental alveoli. The proportion of adult bears affected by periodontitis (57.9%) was significantly greater than that of young adults (22.2%). Exactly half of the specimens (n = 174) possessed lesions consistent with mild temporomandibular joint osteoarthritis. The occurrence and severity of the dental pathology encountered in this study may play an important role in the morbidity and mortality of the American black bear. Copyright © 2016 Elsevier Ltd. All rights reserved.

To Evaluate & Compare Retention of Complete Cast Crown in Natural Teeth Using Different Auxiliary Retentive Features with Two Different Crown Heights - An In Vitro Study.

PubMed

Vinaya, Kundapur; Rakshith, Hegde; Prasad D, Krishna; Manoj, Shetty; Sunil, Mankar; Naresh, Shetty

2015-06-01

To evaluate the retention of complete cast crowns in teeth with adequate and inadequate crown height and to evaluate the effects of auxiliary retentive features on retention form complete cast crowns. Sixty freshly extracted human premolars. They were divided into 2 major groups depending upon the height of the teeth after the preparation. Group1 (H1): prepared teeth with constant height of 3.5 mm and Group 2 (H2): prepared teeth with constant height of 2.5 mm. Each group is further subdivided into 3 subgroups, depending upon the retentive features incorporated. First sub group were prepared conventionally, second sub group with proximal grooves and third subgroups with proximal boxes preparation. Castings produced in Nickel chromium alloy were cemented with glass ionomer cement and the cemented castings were subjected to tensional forces required to dislodge each cemented casting from its preparation and used for comparison of retentive quality. The data obtained were statistically analyzed using Oneway ANOVA test. The results showed there was statistically significant difference between adequate (H1) and inadequate (H2) group and increase in retention when there was incorporation of retentive features compared to conventional preparations. Incorporation of retentive grooves was statistically significant compared to retention obtained by boxes. Results also showed there was no statistically significant difference between long conventional and short groove. Complete cast crowns on teeth with adequate crown height exhibited greater retention than with inadequate crown height. Proximal grooves provided greater amount of retention when compared with proximal boxes.

Effect of photobiomodulation on viability and proliferation of stem cells from exfoliated deciduous teeth under different nutritional conditions

NASA Astrophysics Data System (ADS)

Morato de Souza, Letícia; Guilherme Roque Rinco, Ugo; Aparecida Tavares Aguiar, Daniela; Aparecido de Almeida Junior, Luciano; Cosme-Silva, Leopoldo; Marchini Oliveira, Thais; Teixeira Marques, Nádia Carolina; Thiemy Sakai, Vivien

2018-02-01

This study aimed to evaluate the effect of different doses of low-level laser irradiation on the viability and proliferation of stem cells from exfoliated deciduous teeth (SHED) cultured under nutritional deficit (cellular stress) or regular nutritional conditions. SHED underwent irradiation by a red laser between 1.2 and 6.2 J cm-2. Prior to the irradiation, all groups received culture medium (MEMα, Eagle’s minimum essential medium alpha modification) supplemented with 1% of fetal bovine serum (FBS) for 1 h. After the irradiation, cells received MEMα supplemented with 10% of FBS (regular nutrition) or 1% of FBS (nutritional deficit). Cell viability and proliferation were respectively determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and crystal violet assays 6 and 24 h after irradiation (P  <  0.05). At 24 h, SHED under nutritional deficit showed lower viability and proliferation after 1.2 J cm-2 irradiation. All of the irradiated groups revealed significantly higher viability and proliferation in SHED maintained under nutritional deficit than in regular nutritional conditions, except in the 3.7 and 6.2 J cm-2 groups by MTT assay. In the crystal violet assay, SHED irradiated with 1.2 J cm-2 showed no difference between the different nutritional conditions. Decrease of FBS concentration in the culture medium seems to enhance the sensitivity of SHED to the effects of photobiomodulation therapy. Nutritional stress conditions improved cell viability and proliferation of SHED after laser irradiation, except for 1.2 J cm-2.

Peripheral Nerve Regeneration by Secretomes of Stem Cells from Human Exfoliated Deciduous Teeth.

PubMed

Sugimura-Wakayama, Yukiko; Katagiri, Wataru; Osugi, Masashi; Kawai, Takamasa; Ogata, Kenichi; Sakaguchi, Kohei; Hibi, Hideharu

2015-11-15

Peripheral nerve regeneration across nerve gaps is often suboptimal, with poor functional recovery. Stem cell transplantation-based regenerative therapy is a promising approach for axon regeneration and functional recovery of peripheral nerve injury; however, the mechanisms remain controversial and unclear. Recent studies suggest that transplanted stem cells promote tissue regeneration through a paracrine mechanism. We investigated the effects of conditioned media derived from stem cells from human exfoliated deciduous teeth (SHED-CM) on peripheral nerve regeneration. In vitro, SHED-CM-treated Schwann cells exhibited significantly increased proliferation, migration, and the expression of neuron-, extracellular matrix (ECM)-, and angiogenesis-related genes. SHED-CM stimulated neuritogenesis of dorsal root ganglia and increased cell viability. Similarly, SHED-CM enhanced tube formation in an angiogenesis assay. In vivo, a 10-mm rat sciatic nerve gap model was bridged by silicon conduits containing SHED-CM or serum-free Dulbecco's modified Eagle's medium. Light and electron microscopy confirmed that the number of myelinated axons and axon-to-fiber ratio (G-ratio) were significantly higher in the SHED-CM group at 12 weeks after nerve transection surgery. The sciatic functional index (SFI) and gastrocnemius (target muscle) wet weight ratio demonstrated functional recovery. Increased compound muscle action potentials and increased SFI in the SHED-CM group suggested sciatic nerve reinnervation of the target muscle and improved functional recovery. We also observed reduced muscle atrophy in the SHED-CM group. Thus, SHEDs may secrete various trophic factors that enhance peripheral nerve regeneration through multiple mechanisms. SHED-CM may therefore provide a novel therapy that creates a more desirable extracellular microenvironment for peripheral nerve regeneration.

Effects of mineral trioxide aggregate, BiodentineTM and calcium hydroxide on viability, proliferation, migration and differentiation of stem cells from human exfoliated deciduous teeth

PubMed Central

Araújo, Leandro Borges; Cosme-Silva, Leopoldo; Fernandes, Ana Paula; de Oliveira, Thais Marchini; Cavalcanti, Bruno das Neves; Gomes, João Eduardo; Sakai, Vivien Thiemy

2018-01-01

Abstract Objective The aim of the study was to evaluate the effects of the capping materials mineral trioxide aggregate (MTA), calcium hydroxide (CH) and BiodentineTM (BD) on stem cells from human exfoliated deciduous teeth (SHED) in vitro. Material and Methods SHED were cultured for 1 – 7 days in medium conditioned by incubation with MTA, BD or CH (1 mg/mL), and tested for viability (MTT assay) and proliferation (SRB assay). Also, the migration of serum-starved SHED towards conditioned media was assayed in companion plates, with 8 μm-pore-sized membranes, for 24 h. Gene expression of dentin matrix protein-1 (DMP-1) was evaluated by reverse-transcription polymerase chain reaction. Regular culture medium with 10% FBS (without conditioning) and culture medium supplemented with 20% FBS were used as controls. Results MTA, CH and BD conditioned media maintained cell viability and allowed continuous SHED proliferation, with CH conditioned medium causing the highest positive effect on proliferation at the end of the treatment period (compared with BD and MTA) (p<0.05). In contrast, we observed increased SHED migration towards BD and MTA conditioned media (compared with CH) (p<0.05). A greater amount of DMP-1 gene was expressed in MTA group compared with the other groups from day 7 up to day 21. Conclusion Our results show that the three capping materials are biocompatible, maintain viability and stimulate proliferation, migration and differentiation in a key dental stem cell population. PMID:29412365

Osteogenic differentiation of stem cells derived from human periodontal ligaments and pulp of human exfoliated deciduous teeth.

PubMed

Chadipiralla, Kiranmai; Yochim, Ji Min; Bahuleyan, Bindu; Huang, Chun-Yuh Charles; Garcia-Godoy, Franklin; Murray, Peter E; Stelnicki, Eric J

2010-05-01

Multipotent stem cells derived from periodontal ligaments (PDLSC) and pulp of human exfoliated deciduous teeth (SHED) represent promising cell sources for bone regeneration. Recent studies have demonstrated that retinoic acid (RA) and dexamethasone (Dex) induce osteogenesis of postnatal stem cells. The objective of this study was to examine the effects of RA and Dex on the proliferation and osteogenic differentiation of SHED and PDLSC and to compare the osteogenic characteristics of SHED and PDLSC under RA treatment. SHED and PDLSC were treated with serum-free medium either alone or supplemented with RA or Dex for 21 days. The proliferation of SHED and PDLSC was significantly inhibited by both RA and Dex. RA significantly upregulated gene expression and the activity of alkaline phosphatase in SHED and PDLSC. Positive Alizarin red and von Kossa staining of calcium deposition was seen on the RA-treated SHED and PDLSC after 21 days of culture. The influences of RA on the osteogenic differentiation of SHED and PDLSC were significantly stronger than with Dex. Supplementation with insulin enhanced RA-induced osteogenic differentiation of SHED. Thus, RA is an effective inducer of osteogenic differentiation of SHED and PDLSC, whereas RA treatment in combination with insulin supplementation might be a better option for inducing osteogenic differentiation. Significantly higher cell proliferation of PDLSC results in greater calcium deposition after 3-week culture, suggesting that PDLSC is a better osteogenic stem cell source. This study provides valuable information for efficiently producing osteogenically differentiated SHED or PDLSC for in vivo bone regeneration.

Reciprocating vs Rotary Instrumentation in Pediatric Endodontics: Cone Beam Computed Tomographic Analysis of Deciduous Root Canals using Two Single-file Systems

PubMed Central

Prabhakar, Attiguppe R; Yavagal, Chandrashekar; Naik, Saraswathi V

2016-01-01

ABSTRACT Background: Primary root canals are considered to be most challenging due to their complex anatomy. "Wave one" and "one shape" are single-file systems with reciprocating and rotary motion respectively. The aim of this study was to evaluate and compare dentin thickness, centering ability, canal transportation, and instrumentation time of wave one and one shape files in primary root canals using a cone beam computed tomographic (CBCT) analysis. Study design: This is an experimental, in vitro study comparing the two groups. Materials and methods: A total of 24 extracted human primary teeth with minimum 7 mm root length were included in the study. Cone beam computed tomographic images were taken before and after the instrumentation for each group. Dentin thickness, centering ability, canal transportation, and instrumentation times were evaluated for each group. Results: A significant difference was found in instrumentation time and canal transportation measures between the two groups. Wave one showed less canal transportation as compared with one shape, and the mean instrumentation time of wave one was significantly less than one shape. Conclusion: Reciprocating single-file systems was found to be faster with much less procedural errors and can hence be recommended for shaping the root canals of primary teeth. How to cite this article: Prabhakar AR, Yavagal C, Dixit K, Naik SV. Reciprocating vs Rotary Instrumentation in Pediatric Endodontics: Cone Beam Computed Tomographic Analysis of Deciduous Root Canals using Two Single-File Systems. Int J Clin Pediatr Dent 2016;9(1):45-49. PMID:27274155

Alkaline phosphatase and OCT-3/4 as useful markers for predicting susceptibility of human deciduous teeth-derived dental pulp cells to reprogramming factor-induced iPS cells.

PubMed

Inada, Emi; Saitoh, Issei; Kubota, Naoko; Soda, Miki; Matsueda, Kazunari; Murakami, Tomoya; Sawami, Tadashi; Kagoshima, Akiko; Yamasaki, Youichi; Sato, Masahiro

2017-11-01

The aim of the present study was to prove that primary cells enriched with stem cells are more easily reprogrammed to generate induced pluripotent stem (iPS) cells than those with scarce numbers of stem cells. We surveyed the alkaline phosphatase (ALP) activity in five primarily-isolated human deciduous teeth-derived dental pulp cells (HDDPC) with cytochemical staining to examine the possible presence of stem cells. Next, the expression of stemness-specific factors, such as OCT(Octumer-binding transcription factor)3/4, NANOG, SOX2(SRY (sex determining region Y)-box 2), CD90, muscle segment homeodomain homeobox (MSX) 1, and MSX2, was assessed with a reverse transcription polymerase chain reaction method. Finally, these isolated HDDPC were transfected with plasmids carrying genes coding Yamanaka factors to determine whether these cells could be reprogrammed to generate iPS cells. Of the five primarily-isolated HDDPC, two (HDDPC-1 and -5) exhibited higher degrees of ALP activity. OCT-3/4 expression was also prominent in those two lines. Furthermore, these two lines proliferated faster than the other three lines. The transfection of HDDPC with Yamanaka factors resulted in the generation of iPS cells from HDDPC-1 and -5. The number of cells with the stemness property of HDDPC differs among individuals, which suggests that HDDPC showing an increased expression of both ALP and OCT-3/4 can be more easily reprogrammed to generate iPS cells after the forced expression of reprogramming factors. © 2016 John Wiley & Sons Australia, Ltd.

The effect of stem cell from human exfoliated deciduous teeth on T lymphocyte proliferation

PubMed Central

Alipour, Razieh; Adib, Minoo; Hashemi-Beni, Batool; Sadeghi, Farzaneh

2014-01-01

Background: Mesenchymal stem cells (MSC), a specific type of adult tissue stem cell; have the immunosuppressive effects that make them valuable targets for regenerative medicine and treatment of many human illnesses. Hence, MSC have been the subject of numerous studies. The classical source of MSC is adult bone marrow (BM). Due to many shortcomings of harvesting MSC from BM, finding the alternative sources for MSC is an urgent. Stem cells from human exfoliated deciduous teeth (SHED) are relative new MSC populations that fulfill these criteria but their potential immunosuppressive effect has not been studied enough yet. Thus, in this work the effect of SHED on the proliferation of in vitro activated T lymphocytes were explored. Materials and Methods: In this study, both mitogen and alloantigen activated T cells were cultured in the presence of different numbers of SHED. In some co-cultures, activated T cells were in direct contact to MSCs and in other co-cultures; they were separated from SHED by a permeable membrane. In all co-cultures, the proliferation of T cells was measured by ELISA Bromodeoxyuridine proliferation assay. Results: In general, our results showed that SHED significantly suppress the proliferation of activated T cells in a dose-dependent manner. Moreover, the suppression was slightly stronger when MSCs were in physical contact to activated T cells. Conclusion: This study showed that SHED likewise other MSC populations can suppress the activation of T lymphocytes, which can be used instead of BM derived MSCs in many investigational and clinical applications. PMID:25337532

Development of dental charts according to tooth development and eruption for Turkish children and young adults

PubMed Central

Afşin, Hüseyin; Ozaslan, Abdi; Karadayı, Şükriye

2014-01-01

Purpose In this study, we aimed to develop dental charts for Turkish children and young adults of both genders within the age group of 4.5-22.5 years according to tooth mineralization and eruption in a format similar to that proposed by AlQahtani et al. Materials and Methods In total, 753 digital panoramic radiographs from 350 males and 403 females were assessed. The permanent teeth were evaluated according to the classification system described by Demirjian et al. The eruption stage was assessed with Bengston's system, which was modified by AlQahtani et al at four points. Results Teeth generally developed earlier in females than in males. This was particularly notable in the age group of 5-14 years. However, this difference was usually visible in only one stage, not in all teeth. It has been determined that the mixed dentition period ended with the shedding of the second deciduous molars in both genders. Conclusion The dental charts presented here included information that could be beneficial to dental clinicians in making appropriate diagnosis and planning orthodontic and surgical procedures. These charts also provided datasets for preliminary dental age estimation in Turkish children and young adults. PMID:24944959

First Radiological Study of a Complete Dental Ontogeny Sequence of an Extinct Equid: Implications for Equidae Life History and Taphonomy.

PubMed

Domingo, M Soledad; Cantero, Enrique; García-Real, Isabel; Chamorro Sancho, Manuel J; Martín Perea, David M; Alberdi, M Teresa; Morales, Jorge

2018-05-31

The sequence of cheek teeth mineralization, eruption, and replacement of an extinct horse species is here documented with radiological techniques for the first time thanks to the exceptional preservation of Hipparion sp. mandibles from Cerro de los Batallones (Madrid Basin, Spain). The sequence of dental ontogeny in mammals provides valuable insights about life history traits, such as the pace of growth, and about the mode of formation of fossiliferous assemblages. We have determined that the order of permanent cheek teeth mineralization and eruption of hipparionine horses is m1, m2, (p2, p3), p4, m3. Cheek teeth mineralization timing of hipparionine horses coincides with the one observed in modern equids. In turn, there are differences in the eruption timing of the p4 and m3 between horses belonging to the Anchitheriinae and Hipparionini compared to equids of the Equus genus that might be related to the shorter durability of the deciduous tooth dp4 in anchitheriine and hipparionine horses and, more broadly, to an increased durability of equid teeth through their evolutionary history. Based on the dental eruption sequence, hipparionine horses are slow-growing, long-living mammals. The Hipparion sp. assemblage from Batallones-10 conforms to an attritional model, as individuals more vulnerable to natural mortality predominate.

Identification of sources of lead in children in a primary zinc-lead smelter environment.

PubMed Central

Gulson, Brian L; Mizon, Karen J; Davis, Jeff D; Palmer, Jacqueline M; Vimpani, Graham

2004-01-01

We compared high-precision lead isotopic ratios in deciduous teeth and environmental samples to evaluate sources of lead in 10 children from six houses in a primary zinc-lead smelter community at North Lake Macquarie, New South Wales, Australia. Teeth were sectioned to allow identification of lead exposure in utero and in early childhood. Blood lead levels in the children ranged from 10 to 42 micro g/dL and remained elevated for a number of years. For most children, only a small contribution to tooth lead can be attributed to gasoline and paint sources. In one child with a blood lead concentration of 19.7 microg/dL, paint could account for about 45% of lead in her blood. Comparison of isotopic ratios of tooth lead levels with those from vacuum cleaner dust, dust-fall accumulation, surface wipes, ceiling (attic) dust, and an estimation of the smelter emissions indicates that from approximately 55 to 100% of lead could be derived from the smelter. For a blood sample from another child, > 90% of lead could be derived from the smelter. We found varying amounts of in utero-derived lead in the teeth. Despite the contaminated environment and high blood lead concentrations in the children, the levels of lead in the teeth are surprisingly low compared with those measured in children from other lead mining and smelting communities. PMID:14698931

The Effect of Immediate versus Delayed Dowel Space Preparation on Endodontically Filled Teeth.

DTIC Science & Technology

1981-01-01

solution of 1% sodium hypochlorite (Chlorox Corp., Oakland, CA) to remove any tissue tags attached to the root surface. The crowns of all the teeth were...stored. Two weeks later, twenty more weo~ similarly filled. Using hot endodontic pluggers, dowel spaces were prepare d 4h-th~t eithe 3mm or 71T11 of...Preparation on Endodontically Filled Teeth Acce sion r NTIS .... D TTC TAB Distrilu Av r i 0ou- Dist 1 A! The Effect of Immediate Versus Delayed Dowel

[Evaluation of the cavity cleaning of ultrasonic instruments and slow-speed handpiece in posterior teeth root-end preparation].

PubMed

Zhang, Ping-juan; Chen, Wen-xia; Zeng, Qi-xin; Xie, Fang-fang

2013-04-01

To compare the cleanliness of root end preparations by using ultrasonic instrumentation and slow-speed handpiece. Thirty-two mesial roots of the first mandibular molars with two canals and mature root apices were assigned randomly to 2 groups, each group had 16 teeth. The root-end preparations were made respectively using ultrasonic diamond tip Berutti and NiTi tip RE2 and slow-speed handpiece with No.2 round bur. Root end cavities were examined under scanning electron microscope for further evaluation of the superficial debris and smear layer of the root end preparations. SPSS 13.0 software package was used for Kruskal Wallis test. Ultrasonic preparation had significantly less superficial debris and smear layer than slow-speed handpiece preparation (P<0.05). Ultrasonic instrument creates cleaner surfaces for root end cavities than slow-speed handpiece preparation in posterior teeth root end preparation.

Pulp histology after Er:YAG laser cavity preparation in subhuman primates--a pilot study.

PubMed

Louw, N P; Pameijer, C H; Ackermann, W D; Ertl, T; Cappius, H J; Norval, G

2002-08-01

The aim of the study was to make a direct comparison of the pulpal effects of laser and turbine preparations in subhuman primates. One female baboon (Papio Ursinus ursinus), weighing 15 kg, was used. General anaesthesia was administered (ketamine 100 mg/ml/kg body weight) and maintained with acepromazine (10 mg/ml/kg body weight). Class V cavities were prepared buccally in a total of 28 teeth (7 in each quadrant). Teeth in the upper right and lower left quadrants were prepared using a conventional 330 carbide bur in a high-speed fibre-optic handpiece with copious water spray. Teeth in the upper left and lower right quadrants were prepared using an Er:YAG laser drill (Fotona Twinlight, Llubljana, Slovenia) delivering 500 mJ at a pulse rate of 10 Hz and a wavelength of 2940 nm. The animal was sacrificed after 25 days. After general anaesthesia as described before, perfusion fixation of the head was accomplished with 10% neutral buffered formalin, pumped through a catheter inserted into the left carotid artery. The jaws were removed and, using a 330 carbide bur in a high speed handpiece, a continuous groove was cut through the bone and the roots at the level of the middle third of all the roots to promote thorough fixation of pulpal tissue. Decalcification and grading of the severity of the pulpal responses were conducted according to standard procedures. Owing to procedural errors seven teeth, FDI numbers 23, 24, 31, 34, 35, 44 and 45, had to be eliminated. The turbine-prepared teeth (N = 11) had a mean remaining dentine thickness (RDT) of 0.77 mm (SD = 0.42) and the laser-prepared teeth (N = 10) had a mean RDT of 0.81 mm (SD = 0.60). All pulps appeared normal except in one turbine-prepared tooth (12 with RDT = 0.20) and one laser-prepared tooth (27 with RDT = 0.30, where irreversible damage was caused. The only other deviations from normal were seen in the laser-treated 41 (RDT = 0.69) and the turbine-treated 36 (RDT = 0.77) where moderate hyperaemia was seen. Within the limitations of this study it can be concluded that there is no significant difference between dental pulp of teeth where Class V cavities were prepared with an Er:YAG laser drill compared with those prepared with a standard turbine drill.

Preparation time and perceptions of Brazilian specialists and dental students regarding simulated root canals for endodontic teaching: a preliminary study.

PubMed

dos S Luz, Diandra; de S Ourique, Fernanda; Scarparo, Roberta K; Vier-Pelisser, Fabiana V; Morgental, Renata D; Waltrick, Silvana B G; de Figueiredo, José A P

2015-01-01

The aim of this preliminary study was to evaluate the desirability of alternative models of artificial teeth versus extracted natural teeth for use in preclinical dental education. Specifically, the study was designed to compare the preparation time and perceptions of difficulty of undergraduate dental students and endodontists in carrying out root canal preparations on resin models (both clear and opaque) and extracted natural teeth. Twenty participants-ten fifth-year students at a Brazilian dental school and ten endodontists with at least five years' experience in the specialty-performed root canal instrumentation on two samples of each model. Preparation times were recorded, and the participants completed a questionnaire about the anatomical and physical characteristics of these models. The results showed that the time required for performing endodontic procedures in the natural teeth was higher than in the alternative models. The perceptions of the students and specialists regarding some topics on the questionnaire were significantly different. The students had more positive opinions about artificial teeth made of opaque resin, while the specialists had more positive opinions about simulated root canals in clear resin blocks. This study suggests that neither of the alternative models fulfilled requirements to replace natural teeth in endodontic teaching; improvements are still necessary to accomplish this goal.

The prevalence of premature loss of primary teeth and its impact on malocclusion in the Eastern Province of Saudi Arabia.

PubMed

Al-Shahrani, Nasser; Al-Amri, Abdulaziz; Hegazi, Fahad; Al-Rowis, Khalid; Al-Madani, Abdullah; Hassan, Khalid S

2015-01-01

The present study was designed to determine the prevalence of premature loss of primary teeth and its effect on malocclusion in Eastern Province, Saudi Arabia. This is an observational, cross-sectional study that included 307 male children aged 9-11 years old. Clinical examinations were performed using a disposable sharp explorer, a UNC periodontal probe and a dental mirror. The samples were examined clinically to detect the following traits: Angle's classification of malocclusion, overjet, overbite, anterior open-bite, lateral open-bite, midline shift and cross-bite. Additionally, a dental caries examination was performed using WHO methods. Questionnaires in Arabic were coded and sent to the students' parents. The mean DMFT was 5.61 (SD = 3.01). The d-component was the highest, with a mean of 4 (SD = 2.83). Of the 307 children, it was found that 204 (66.4%) had a high DMFT score, which is defined as a score above 4. It was found that 156/307 (51%) children had premature loss of deciduous teeth. A high prevalence of premature loss of teeth was found in this study. This finding emphasizes the importance of increasing awareness levels about this issue and focuses attention on the need for more preventive efforts to maintain healthy and normal dentitions that would improve the masticatory function and aesthetics of individuals and the whole population. In addition, the findings emphasize the importance of the early detection of premature loss of primary teeth to prevent future malocclusion.

Conservative Management of Dens Evaginatus: Report of Two Unusual Cases

PubMed Central

Vijaykumar, S; Tenny, J; Ravi, GR

2010-01-01

ABSTRACT Dens evaginatus (DE) is a rare developmental anomaly characterized by presence of an extra cusp arising from occlusal or lingual surfaces. Isolated occurrence or concomitant presence of DE with other dental anomalies has been reported. DE commonly affects permanent teeth and is rarely seen in primary dentition. Treatment may be conservative or radical. This article presents two unusual cases of concomitant occurrence of a supernumerary tooth and DE affecting maxillary deciduous lateral incisor and conservative management of DE occurring concurrently with a possible Oehler’s type I invagination in maxillary permanent lateral incisor. PMID:27507925

Clinical Evaluation of Quality of Obturation and Instrumentation Time using Two Modified Rotary File Systems with Manual Instrumentation in Primary Teeth.

PubMed

Govindaraju, Lavanya; Jeevanandan, Ganesh; Subramanian, Emg

2017-09-01

Pulp therapy in primary teeth has been performed using various instrumentation techniques. However, the conventional instrumentation technique used for root canal preparation in primary teeth is hand instrumentation. Various Nickel-Titanium (Ni-Ti) instruments are available to perform efficient root canal preparation in primary teeth. These Ni-Ti instruments has been designed to aid in better root canal preparation in permanent teeth but are rarely used in primary teeth. It is necessary to assess the feasibility of using these adult rotary files with a modified sequence in primary teeth. To compare the quality of obturation and instrumentation time during root canal preparation using hand files and modified rotary file systems in primary molars. Forty-five primary mandibular molars were randomly assigned to three experimental groups (n=15). Group I was instrumented using k-hand files, Group II with S2 ProTaper universal file and Group III with 0.25 tip 4% taper K3 rotary file. Standardized digital radiographs were taken before and after root canal instrumentation. Root canal preparation time was also recorded. Statistical analysis of the obtained data was done using SPSS Software version 17.0. An intergroup comparison of the instrumentation time and the quality of obturation was done using ANOVA and Chi-square test with the level of significance set at 0.05. No significant differences were noted with regard to the quality of obturation (p=0.791). However, a statistically significant difference was noted in the instrumentation time between the three groups (p<0.05). ProTaper rotary system had significantly lesser instrumentation time when compared to that of K3 rotary system and hand file system. The hand files, S2 ProTaper Universal and K3 0.25 tip 4% taper files systems performed similarly with respect to the quality of obturation. There was a significant difference in instrumentation time with manual instrumentation compared to the modified rotary file systems in primary teeth.

Assessment of Er:YAG laser for cavity preparation in primary and permanent teeth: a scanning electron microscopy and thermographic study.

PubMed

Al-Batayneh, Ola B; Seow, W Kim; Walsh, Laurence J

2014-01-01

Most studies of cavity preparation using Er:YAG lasers have employed permanent teeth. This study's purpose was to compare the cutting efficiency of an Er:YAG laser versus diamond burs in primary and permanent teeth in order to measure thermal effects on the pulp and evaluate lased surfaces using scanning electron microscopy (SEM). A total of 80 primary and permanent teeth were used. Crater depths and mass loss were measured after delivering laser pulses at varying energies onto sound or carious enamel or dentin using the Key-3 laser. Control samples were cut using diamond burs in an air turbine handpiece. Thermal changes were measured using miniature thermocouples placed into the pulp chamber. Lased surfaces were evaluated using SEM. Laser ablation crater-like defects were deeper in dentin than enamel at the same pulse energy. Greater ablation rates for dentin and enamel and significantly more efficient removal of carious tooth structure by laser was present in primary teeth. Temperature rises in the pulp did not exceed the 5.5 degrees Celsius threshold in any teeth during laser ablation. The Er:YAG laser is an efficient device for cavity preparations in primary teeth, with no unacceptable increases in temperature detected in this model.

Comparison between rotary and manual instrumentation in primary teeth.

PubMed

Crespo, S; Cortes, O; Garcia, C; Perez, L

2008-01-01

The aim of this study was to compare the efficiency in both, preparation time and root canal shape, when using the Nickel Titanium (Ni-Ti) rotary and K-Files hand instrumentation on root canal preparation of single rooted primary teeth. Sixty single rooted primary teeth were selected and divided into two equal groups: Group (I) 30 teeth instrumented with manual K-files and group (II) 30 teeth instrumented with Ni-Ti rotary files (ProFile 0.04). Instrumentation times were calculated and root canal impressions were taken with light bodied silicone in order to evaluate the shape. The data was analyzed with SPSS program using the t-test and the Chi-square test to compare their means. The preparation time with group (I) K-files was significantly higher than in group (II) rotary files (ProFile 0.04), with a p= .005. The ProFile system showed a significantly more favorable canal taper when compared to the K-files system (P= .002). The use of rotary files in primary teeth has several advantages when compared with manual K files: the efficiency in both, preparation time and root canal shape. 1. A decreased working time, that helps maintain patient cooperation by diminishing the potential for tiredness. 2. The shape of the root canal is more conical, favoring a higher quality of the root canal filling, and increasing clinical success.

Quarter of a century of change: caries experience in Australian children, 1977-2002.

PubMed

Armfield, J M; Spencer, A J

2008-06-01

The establishment of the evaluation programme of the Australian School Dental Scheme has led to continuous surveillance of child oral health extending from 1977 to the present day. The aims of this study were to examine the state of child oral health in Australia in 2002 and to explore longer term trends across the quarter of a century of recorded surveillance activity. Caries data were obtained for children who were enrolled in the School Dental Services of each state and territory for the years 1977-2002. Data collection derived from routine examinations within the School Dental Service with oral examinations carried out by dentists and dental therapists. There were considerable declines in caries experience between 1977 and the mid to late 1990s, with mean decayed, missing and filled deciduous teeth (dmft) for 6-year-old children decreasing from over 3 in 1977 to approximately 1.6 in 1996, and permanent 12-year-old decayed, missing and filled teeth (DMFT) decreasing from 4.8 in 1977 to 0.89 in 1998. However, since the mid to late 1990s, deciduous 6-year-old dmft has increased by 24 per cent and 12-year-old DMFT has increased by almost 15 per cent. Reductions in caries experience of those children with the most disease have also ceased, and between 1999 and 2002 an increase in the Significant Caries Index occurred. Improvements in the oral health of Australian children halted during the mid 1990s, after which caries experience has increased. It is important that we understand the changes taking place and their causes, so that action can be taken to halt any further possible declines in child oral health.

Immunomodulatory Role of Stem Cells from Human Exfoliated Deciduous Teeth on Periodontal Regeneration.

PubMed

Gao, Xianling; Shen, Zongshan; Guan, Meiliang; Huang, Qiting; Chen, Lingling; Qin, Wei; Ge, Xiaohu; Chen, Haijia; Xiao, Yin; Lin, Zhengmei

2018-05-09

Periodontitis is initiated by the infection of periodontal bacteria and subsequent tissue inflammation due to immunoreaction, eventually leading to periodontal apparatus loss. Stem cells from human exfoliated deciduous teeth (SHEDs) have exhibited beneficial characteristics in dental tissue regeneration. However, the immunomodulatory functions of SHEDs have not been elucidated in the context of periodontitis treatment. In this study, we investigated the potential immunomodulatory effects of SHEDs on experimental periodontitis and demonstrated that multidose delivery of SHEDs led to periodontal tissue regeneration. SHEDs and monocytes/macrophages were cocultured in transwell systems and SHEDs were found to be capable of promoting monocyte/macrophage conversion to CD206 + M2-like phenotype. Bioluminescence imaging (BLI) was employed to assess the survival and distribution of SHEDs after delivery in periodontal tissues in an induced periodontitis model, and BLI revealed that SHEDs survived for ∼7 days in periodontal tissues with little tissue diffusion. Then, multidose SHED delivery was applied to treat periodontitis at 7-day intervals. Results showed that mutidose SHEDs altered the cytokine expression profile in gingival crevicular fluid, reduced gum bleeding, increased new attachment of periodontal ligament, and decreased osteoclast differentiation. Micro-computed tomography analysis showed SHED administration significantly increased periodontal regeneration and alveolar bone volume, and decreased distance of cementoenamel junction to alveolar bone crest. Furthermore, an increase in the number of CD206 + M2 macrophages was observed in periodontal tissues following the delivery of SHEDs, which aligned well with the promoted conversion to CD206 + M2-like cells from monocytes/macrophages in vitro after stimulation by SHEDs. This study demonstrated in a rat periodontitis model that local delivery of SHEDs attributed to the induction of M2 macrophage polarization, reduction of periodontal tissue inflammation, and enhancement of periodontal regeneration.

Fragile X syndrome: panoramic radiographic evaluation of dental anomalies, dental mineralization stage, and mandibular angle

PubMed Central

Sabbagh-Haddad, Aida; Haddad, Denise Sabbagh; Michel-Crosato, Edgard; Arita, Emiko Saito

2016-01-01

ABSTRACT Fragile X syndrome (FXS) is a disorder linked to the chromosome X long arm (Xq27.3), which is identified by a constriction named fragile site. It determines various changes, such as behavioral or emotional problems, learning difficulties, and intellectual disabilities. Craniofacial abnormalities such as elongated and narrow face, prominent forehead, broad nose, large and prominent ear pavilions, strabismus, and myopia are frequent characteristics. Regarding the oral aspects, deep and high-arched palate, mandibular prognathism, and malocclusion are also observed. Objective: The purpose of this study was to evaluate the dental radiographic characteristics as described in 40 records of patients with panoramic radiography. Material and Methods: The patients were in the range of 6–17 years old, and were divided into two groups (20 subjects who were compatible with the normality standard and 20 individuals diagnosed with the FXS), which were matched for gender and age. Analysis of the panoramic radiographic examination involved the evaluation of dental mineralization stage, mandibular angle size, and presence of dental anomalies in both deciduous and permanent dentitions. Results: The results of radiographic evaluation demonstrated that the chronology of tooth eruption of all third and second lower molars is anticipated in individuals with FXS (p<0.05). In this group, supernumerary deciduous teeth (2.83%), giroversion of permanent teeth (2.31%), and partial anodontia (1.82%) were the most frequent dental anomalies. In addition, an increase was observed in the mandibular angle size in the FXS group (p<0.05). Conclusion: We conclude that knowledge of dental radiographic changes is of great importance for dental surgeons to plan the treatment of these individuals. PMID:27812623

Meta-analysis of the prevalence of tooth wear in primary dentition.

PubMed

Corica, A; Caprioglio, A

2014-12-01

To conduct a meta-analysis of all the studies published in literature over the past three decades on the prevalence of dental erosion in preschool children. The Pubmed data base revealed only one systematic review on the prevalence of tooth wear in children up to 5 years old. The search included works published from January 1982 to September 2012, using the following combinations of keywords: 1) "dental erosion" AND "children"; 2) "dental erosion in primary dentition"; 3) "dental" AND "attrition" AND "prevalence". The inclusion criteria for papers on tooth wear were the deciduous dentition observed only on the palatal and buccal sides with the distinction of erosion, attrition and abrasion. We took into consideration only randomized control trials. We excluded articles not written in English, case reports, historical and forensic studies, in vitro and in vivo studies. In case of doubt and/or when an abstract was not available, the full text copy of the article was examined. The first search on Pubmed revealed 29 articles, the same found in the study of Kreulen [2010], however we selected only multicentric studies focused on children of age below 5 years old, in which only the primary dentition (D) and only anterior teeth (incisors) were considered. Both forest plot and scatter plot showed the prevalence of dental erosion in primary dentition, and that older children had a more severe dental erosion. Dental erosion should be considered a paediatric dentistry pathological entity as well as dental caries, and it can be related to more severe systemic diseases such as Gastroesophageal reflux disease. In addition, taking care of these little patients is important because they might suffer persentiveness, and also pulpal pathology caused by the typical structure of deciduous teeth, where the pulp cavity is wide and close to the dentine and the enamel.

The early Pleistocene deciduous hominid molar FS-72 from the Sangiran Dome of Java, Indonesia: A taxonomic reappraisal based on its comparative endostructural characterization.

PubMed

Zanolli, Clément; Grine, Frederick E; Kullmer, Ottmar; Schrenk, Friedemann; Macchiarelli, Roberto

2015-08-01

Among the ten fossil hominid deciduous teeth reported so far from the Pleistocene sediments of the Sangiran Dome of Java are two isolated lower second molars: specimens PCG.2 from the Kabuh Formation and FS-72 from the Pucangan Formation. While PCG.2 appears to be certainly attributable to Homo erectus, FS-72 is somewhat more problematic, even though it is commonly listed within the Indonesian H. erectus hypodigm. Largely because of its large size, it was originally attributed to Meganthropus paleojavanicus. Subsequent study highlighted a set of metric and nonmetric crown features also found in Australopith and African early Homo (notably H. habilis) homologues. An additional problem with the taxonomic assignment of isolated teeth from the Pleistocene of Java is the presence of Pongo in these same deposits. To assess the taxonomic affinity of FS-72, we investigated its inner structure (tissue proportions and enamel-dentine junction morphology) by using techniques of 2-3D virtual imaging coupled with geometric morphometric analyses. The results show that FS-72 has thinner enamel compared to fossil and recent humans and that its topographic repartition more closely follows the pongine pattern. It also exhibits a Pongo-like elongated morphology of the enamel-dentine junction, with proportionally lower and mesiodistally spaced dentine horns. Given the morphological and metric similarities between fossil orangutan and H. erectus molars, we tested the hypothesis that its internal morphology more closely resembles the patterns evinced by PCG.2 and modern humans than Pongo. Accordingly, we consider that FS-72 more likely represents a dm2 of Pongo rather than Homo. © 2015 Wiley Periodicals, Inc.

Considerations for Altering Preparation Designs of Porcelain Inlay/Onlay Restorations for Nonvital Teeth.

PubMed

Homsy, Foudda; Eid, Rita; El Ghoul, Wiam; Chidiac, Jose Johann

2015-08-01

The aim of this study was to compare all ceramic inlay/onlay survival rates in vital and nonvital teeth having the same cavity design. Filling the pulp chamber with ceramic materials or not was also discussed. Ceramic class II inlays/onlays were made on 11 premolars and 30 molars: 14 vital, 27 endodontically treated. The same tooth preparation design was performed on vital and nonvital teeth: In nonvital teeth the pulp chambers were covered by a glass ionomer cement until the pulpal floor depths were between 2 and 2.5 mm, more likely similar to the vital teeth preparations. In vital teeth, glass ionomer was used as a liner to achieve pulpal floor depths between 2 and 2.5 mm when needed. The restorations were assessed (at baseline, 6 months, 1 and 2 years) according to three criteria: marginal discoloration, marginal integrity, and fracture of teeth/restorations, consistent with United States Public Health Service (USPHS) criteria. Eight teeth (19%) showed minor marginal discolorations, while three molars (7%) had loss of marginal integrity. These margins were adjusted using rubber polishing cups and were then judged clinically acceptable. From these three molars, one was vital and two were endodontically treated. No fracture of teeth or restorations was observed. Chi square and exact probability tests were used. There was no statistical difference between vital and nonvital teeth (p = 0.719 chi-squared and Fisher) or between premolars and molars (p = 0.564 chi-squared; 1.000, Fisher). Within the limitations of this study there was no difference for the same inlay/onlay cavity design between vital and nonvital teeth. In nonvital teeth, it seems that filling the pulp chamber with a ceramic core material is not important. Long-term observation periods are needed to reinforce the clinical behavior outcome. © 2015 by the American College of Prosthodontists.

The behaviour of post-retained core materials supported by coronal tooth structure in vitro.

PubMed

Russell, M D; Masood, M; Cunningham, L

1997-11-01

This study was designed to investigate the effect of retaining coronal tooth substance on the performance of post-retained core materials, and to compare the fracture resistance of the system with an intact tooth prepared to similar dimensions. Ten teeth restored with post-retained silver amalgam, and 10 teeth restored with silver-glass cermet, all with a retained single wall of coronal tooth substance, were compared with 10 unrestored teeth prepared to similar dimensions when subjected to a shearing load. The results showed no statistically significant difference between the unrestored teeth and those restored with a silver-glass cermet. Whilst the teeth restored with silver amalgam had a significantly higher fracture resistance (P > 0.01) there was greater tendency to root fracture.

Awareness of Stem cells & Health Implications of SHED found in Pediatric Dentition among Indian Population

PubMed Central

Goomer, Pallvi; Sidhu, Arshpreet Kaur; Tuli, Preety; Kansal, Shinam; Bansal, Kanishka; Thakre, Gauri R

2014-01-01

Background: Primary teeth may be an ideal source of postnatal stem cells to regenerate tooth structures and bone, and possibly to treat neural tissue injury or degenerative diseases. SHED (stem cells from human exfoliated deciduous teeth) were identified to be a population of highly proliferative, clonogenic cells capable of differentiating into a variety of cell types including neural cells, adipocytes, and odontoblasts. The present study was carried out to assess the knowledge, awareness & attitude of parents visiting various dental clinics in tricity area of india regarding stem cells from primary teeth and their potential health benefits. Materials & Methods: A total of 250 parents of pediatric patients seeking dental treatment at various dental clinics in tricity area were included in the study. Parents were personally interviewed with a questionnaire and their responses were immediately computed. Results: Among 250 parents only 95(62%) had knowledge regarding stem cells. While only 47(18.8) were informed regarding stem cells from baby teeth & their benefits. Maximum subjects were informed through internet 21(44.6%) followed by information through friends(23.4%) and dentist(21.2%). Very few were informed through magazines, newspaper and only one (2.1%) person was informed by television. Conclusion: It is important to create more awareness among the populace of our country about the potential health benefits of stem cells from primary teeth. Dentist should educate parents, caregivers and teachers regarding SHED & its benefits, ensuring good health for every Indian child and hence health of future citizens. How to cite the article: Goomer P, Sidhu AK, Tuli P, Kansal S, Bansal K, Thakre GR. Awareness of Stem cells & Health Implications of SHED found in Pediatric Dentition among Indian Population. J Int Oral Health 2014;6(1):44-7. PMID:24653602

Comparison of Micro-Leakage from Resin-Modified Glass Ionomer Restorations in Cavities Prepared by Er:YAG (Erbium-Doped Yttrium Aluminum Garnet) Laser and Conventional Method in Primary Teeth

PubMed Central

Bahrololoomi, Zahra; Razavi, Forooghosadat; Soleymani, Ali Asghar

2014-01-01

Introduction: In recent years, significant developments have been taking place in caries removal and cavity preparation using laser in dentistry. As laser use is considered for cavity preparation, it is necessary to determine the quality of restoration margins. Glass ionomer cements have great applications for conservative restoration in the pediatric field. The purpose of this in vitro study was to compare resin-modified glass ionomer restorations micro-leakage in cavities prepared by Er:YAG (Erbium-Doped Yttrium Aluminum Garnet) laser irradiation and conventional method in primary teeth. Methods: This was an in vitro experimental study. Forty primary canine teeth were divided into 2 groups: group 1 represented cavities prepared by the no. 008 diamond bur, group 2 represented cavities prepared by Er:YAG laser. After cavity preparation, samples were restored by resin-modified glass ionomer. The teeth were thermocycled for 700 cycles, placed in 2% methylene blue for 24h and sectioned in the buccolingual direction. The degree of dye penetration was scored by 3 examiners. Data was analyzed using Mann-Whitney Test. Results: There was no statistical difference in micro-leakage between the two modes of cavity preparation (P=0.862) Conclusion: Since preparing conservative cavities is very important in pediatric dentistry, it is possible to use Er:YAG laser because of its novel and portable technology. However, further investigations of other restorative materials and other laser powers are required. PMID:25653819

Overdentures on natural teeth: a new approach.

PubMed

Previgliano, V; Barone Monfrin, S; Santià, G; Preti, G

2004-01-01

The study presents a new type of copings for overdentures on natural teeth. A new type of custom-made copings was prepared on 10 extracted teeth and their marginal fit was observed microscopically by means of a mechanical device, and software was employed to measure the gap. The marginal fit evaluation gave satisfactory values with mean values of the gap measurements below the clinically accepted limits (mean gap: 25.3 microm; minimum 7.3 microm, maximum 56.5 microm). The advantages of these new copings are: the rapidity of their preparation; the protection of the root canal treatment, because the coping with this chair-side method is prepared and cemented in one session; the low costs.

Clinical Evaluation of Quality of Obturation and Instrumentation Time using Two Modified Rotary File Systems with Manual Instrumentation in Primary Teeth

PubMed Central

Govindaraju, Lavanya; Subramanian, EMG

2017-01-01

Introduction Pulp therapy in primary teeth has been performed using various instrumentation techniques. However, the conventional instrumentation technique used for root canal preparation in primary teeth is hand instrumentation. Various Nickel-Titanium (Ni-Ti) instruments are available to perform efficient root canal preparation in primary teeth. These Ni-Ti instruments has been designed to aid in better root canal preparation in permanent teeth but are rarely used in primary teeth. It is necessary to assess the feasibility of using these adult rotary files with a modified sequence in primary teeth. Aim To compare the quality of obturation and instrumentation time during root canal preparation using hand files and modified rotary file systems in primary molars. Materials and Methods Forty-five primary mandibular molars were randomly assigned to three experimental groups (n=15). Group I was instrumented using k-hand files, Group II with S2 ProTaper universal file and Group III with 0.25 tip 4% taper K3 rotary file. Standardized digital radiographs were taken before and after root canal instrumentation. Root canal preparation time was also recorded. Statistical analysis of the obtained data was done using SPSS Software version 17.0. An intergroup comparison of the instrumentation time and the quality of obturation was done using ANOVA and Chi-square test with the level of significance set at 0.05. Results No significant differences were noted with regard to the quality of obturation (p=0.791). However, a statistically significant difference was noted in the instrumentation time between the three groups (p<0.05). ProTaper rotary system had significantly lesser instrumentation time when compared to that of K3 rotary system and hand file system. Conclusion The hand files, S2 ProTaper Universal and K3 0.25 tip 4% taper files systems performed similarly with respect to the quality of obturation. There was a significant difference in instrumentation time with manual instrumentation compared to the modified rotary file systems in primary teeth. PMID:29207834

Computed Tomographic Evaluation of K3 Rotary and Stainless Steel K File Instrumentation in Primary Teeth

PubMed Central

Kavitha, Swaminathan; Thomas, Eapen; Anadhan, Vasanthakumari; Vijayakumar, Rajendran

2016-01-01

Introduction The intention of root canal preparation is to reduce infected content and create a root canal shape allowing for a well condensed root filling. Therefore, it is not necessary to remove excessive dentine for successful root canal preparation and concern must be taken not to over instrument as perforations can occur in the thin dentinal walls of primary molars. Aim This study was done to evaluate the time preparation, the risk of lateral perforation and dentine removal of the stainless steel K file and K3 rotary instrumentation in primary teeth. Materials and Methods Seventy-five primary molars were selected and divided into three groups. Using spiral computed tomography the teeth were scanned before instrumentation. Teeth were prepared using a stainless steel K file for manual technique. All the canals were prepared up to file size 35. In K3 rotary files (.02 taper) instrumentation was done up to 35 size file. In K3 rotary files (.04 taper) the instrumentation was done up to 25 size file and simultaneously the instrumentation time was recorded. The instrumented teeth were once again scanned and the images were compared with the images of the uninstrumented canals. Statistical Analysis Data was statistically analysed using Kruskal Wallis One-way ANOVA, Mann-Whitney U-Test and Pearson’s Chi-square Test. Results K3 rotary files (.02 taper) removed a significantly less amount of dentine, required less instrumentation time than a stainless steel K file. Conclusion K3 files (.02 taper) generated less dentine removal than the stainless steel K file and K3 files (.04 taper). K3 rotary files (.02 taper) were more effective for root canal instrumentation in primary teeth. PMID:26894166

Effect of apical clearing technique on the treatment outcome of teeth with asymptomatic apical periodontitis: A randomized clinical trial

PubMed Central

Mittal, Priya; Logani, Ajay; Shah, Naseem; Pandey, R. M.

2016-01-01

Aim: This study aims to compare the periapical healing of teeth with asymptomatic apical periodontitis treated either by conventional apical preparation (CAP) or apical clearing technique (ACT). Materials and Methods: Twenty subjects with bilateral nonvital similar teeth exhibiting comparable periapical index (PAI) score were enrolled and randomly allocated. Group I (CAP, n = 20): Apical preparation three sizes greater (master apical file [MAF]) than the first binding file at the established working length. Group II (ACT, n = 20): Apical preparation three sizes greater than the MAF that was followed by dry reaming. Root canal therapy was accomplished in single-visit for all the teeth. They were pursued radiographically at 3, 6, 9 and 12 months. Pre- and post-treatment PAI scores were compared. To ascertain the proportion of healed teeth between the two groups, McNemar Chi-square test was applied. Results: At 3, 6, and 9 months’ time interval the proportion of healed teeth for Group II (ACT) was greater in comparison to Group I (CAP) (P < 0.05). However, at 12 months follow-up period this difference was not significant (P = 0.08). Conclusion: ACT enhanced the healing kinetics. However, the long-term (12 months) radiographic outcome was similar for either technique. PMID:27656054

Effect of apical clearing technique on the treatment outcome of teeth with asymptomatic apical periodontitis: A randomized clinical trial.

PubMed

Mittal, Priya; Logani, Ajay; Shah, Naseem; Pandey, R M

2016-01-01

This study aims to compare the periapical healing of teeth with asymptomatic apical periodontitis treated either by conventional apical preparation (CAP) or apical clearing technique (ACT). Twenty subjects with bilateral nonvital similar teeth exhibiting comparable periapical index (PAI) score were enrolled and randomly allocated. Group I (CAP, n = 20): Apical preparation three sizes greater (master apical file [MAF]) than the first binding file at the established working length. Group II (ACT, n = 20): Apical preparation three sizes greater than the MAF that was followed by dry reaming. Root canal therapy was accomplished in single-visit for all the teeth. They were pursued radiographically at 3, 6, 9 and 12 months. Pre- and post-treatment PAI scores were compared. To ascertain the proportion of healed teeth between the two groups, McNemar Chi-square test was applied. At 3, 6, and 9 months' time interval the proportion of healed teeth for Group II (ACT) was greater in comparison to Group I (CAP) (P < 0.05). However, at 12 months follow-up period this difference was not significant (P = 0.08). ACT enhanced the healing kinetics. However, the long-term (12 months) radiographic outcome was similar for either technique.

Success of Maxillary Alveolar Defect Repair in Rats Using Osteoblast-Differentiated Human Deciduous Dental Pulp Stem Cells.

PubMed

Jahanbin, Arezoo; Rashed, Roozbeh; Alamdari, Daryoush Hamidi; Koohestanian, Niloufar; Ezzati, Atefeh; Kazemian, Mojgan; Saghafi, Shadi; Raisolsadat, Mohammad Ali

2016-04-01

The use of cell-based therapies represents one of the most advanced methods for enhancing the regenerative response in craniofacial abnormalities. The main aim of this study was to evaluate the regenerative potential of human dental pulp stem cells, isolated from deciduous teeth, for reconstructing maxillary alveolar defects in Wistar rats. Human deciduous dental pulp stem cells were isolated and stimulated to differentiate into osteoblasts in culture media. Maxillary alveolar defects were created in 60 Wistar rats by a surgical procedure. Then, on the basis of the type of graft used to repair the bone defect, the rats were divided into 6 equal groups: groups 1 and 2, transplantation of iliac bone graft; groups 3 and 4, transplantation of stem cells derived from deciduous dental pulp in addition to collagen matrix; groups 5 and 6, transplantation of just collagen matrix. Then, fetal bone formation, granulation tissue, fibrous tissue, and inflammatory tissue were evaluated by hematoxylin-eosin staining at 1 month (groups 1, 3, and 5) and 2 months (groups 2, 4, and 6) after surgery, and data were analyzed and compared using the Fisher exact test. Maximum fetal bone formation occurred in group 2, in which iliac bone graft was inserted into the defect area for 2 months; there also were significant differences among the groups for bone formation (P = .009). In the 1-month groups, there were no significant differences between the control and stem cell-plus-scaffold groups. There were significant differences between the 2-month groups for fetal bone formation only between the control and scaffold groups (P = .026). The study showed that human dental pulp stem cells are an additional cell resource for repairing maxillary alveolar defects in rats and constitute a promising model for reconstruction of human maxillary alveolar defects in patients with cleft lip and palate. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Dental and Temporomandibular Joint Pathology of the Polar Bear (Ursus maritimus).

PubMed

Winer, J N; Arzi, B; Leale, D M; Kass, P H; Verstraete, F J M

2016-01-01

Museum specimens (maxillae and/or mandibles) from 317 polar bears (Ursus maritimus) were examined macroscopically according to predefined criteria and 249 specimens were included in this study. The specimens were acquired between 1906 and 2011. There were 126 specimens (50.6%) from male animals, 93 (37.3%) from female animals and 30 (12.1%) from animals of unknown sex. The ages of the animals ranged from neonate to adult, with 125 adults (50.2%) and 124 young adults (49.8%) included and neonates/juveniles excluded from the study. The number of teeth available for examination was 7,638 (73.5%); 12.3% of teeth were absent artefactually, 0.8% were deemed absent due to acquired tooth loss and 13.4% were absent congenitally. With respect to tooth morphology, 20 teeth (0.26% of available teeth) in 18 specimens (7.2% of available specimens) were small vestigial structures with crowns that were flush with the level of surrounding alveolar bone. One supernumerary tooth and one tooth with enamel hypoplasia were encountered. Persistent deciduous teeth and teeth with an aberrant number of roots were not found. Relatively few teeth (3.7%) displayed attrition/abrasion, 90% of which were the maxillary and mandibular incisor teeth, in 41 polar bears (16.5%). Nearly twice as many adult specimens exhibited attrition/abrasion as those from young adults; significantly more males were affected than females. Dental fractures were noted in 52 polar bears, affecting 20.9% of specimens and 1.3% of the total number of teeth present. More adult polar bears had dental fractures than young adults. There were 21 specimens (8.4%) that displayed overt periapical disease, affecting a total of 24 dental alveoli (0.23%). Some degree of periodontitis was seen in 199 specimens (79.9%); however, only 12.6% of dental alveoli had bony changes indicative of periodontitis. Lesions consistent with temporomandibular joint osteoarthritis (TMJ-OA) were found in 23 specimens (9.2%). TMJ-OA was significantly more common in adults than in young adults and in males than in females. Although the clinical significance of dental and TMJ pathology in the polar bear remains elusive, the occurrence and severity of these lesions may play an important role in the morbidity and mortality of this species. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biocompatibility Evaluation of Four Dentin Adhesives Used as Indirect Pulp Capping Materials

PubMed Central

Cortés, Olga; Bernabé, Antonia

2017-01-01

Background In many cases, the indirect pulp treatment (IPT) is an acceptable treatment for deciduous teeth with reversible pulp inflammation. Various medicaments have been used for IPT, ranging from calcium hydroxide and glass ionomers to dentin adhesives. Objective This in vitro trial aimed to measure cytotoxicity in a cell culture, comparing the following four adhesives: Xeno® V (XE), Excite® F DSC (EX), Adhese® OneF (AD) and Prime & Bond NT (PB). Materials and methods The adhesives were prepared according to the manufacturer’s instructions. After 24 hours of exposure, the cell viability was evaluated using a photometrical test (MTT test). Data were subjected to analysis of variance (ANOVA). Results Adhesives, the main component of which was 2-hydroxyethyl methacrylate (HEMA), were found to be less cytotoxic, while those that included the monomer urethane dimethacrylate (UDMA were the most cytotoxic) in their composition. The effects on cell viability assay varied between the adhesives assayed with statistically significant differences. Conclusions The results may support the argument that Adhese® OneF is the least cytotoxic of the adhesives assayed, and may be considered as an adhesive agent for indirect pulp treatment. However, Prime and Bond NT showed a reduced biocompatibility under the same conditions. PMID:28827848

Enamel hypoplasias and physiological stress in the Sima de los Huesos Middle Pleistocene hominins.

PubMed

Cunha, E; Rozzi, F Ramirez; Bermúdez de Castro, J M; Martinón-Torres, M; Wasterlain, S N; Sarmiento, S

2004-11-01

This study presents an analysis of linear enamel hypoplasias (LEH) and plane-form defects (PFD) in the hominine dental sample from the Sima de los Huesos (SH) Middle Pleistocene site in Atapuerca (Spain). The SH sample comprises 475 teeth, 467 permanent and 8 deciduous, belonging to a minimum of 28 individuals. The method for recording PFD and LEH is discussed, as well as the definition of LEH. The prevalence of LEH and PFD in SH permanent dentition (unilateral total count) is 4.6% (13/280). Only one deciduous tooth (lower dc) showed an enamel disruption. Prevalence by individual ranges from 18.7-30%. The most likely explanation for the relatively low LEH and PFD prevalence in the SH sample suggests that the SH population exhibited a low level of developmental stress. The age at occurrence of LEH and PFD was determined by counting the number of perikymata between each lesion and the cervix of the tooth. Assuming a periodicity of nine days for the incremental lines, the majority of LEH in the SH sample occurred during the third year of life and may be related to the metabolic stress associated with weaning.

Comparative study between laser and conventional techniques for class V cavity preparation in gamma-irradiated teeth (in vitro study).

PubMed

Rasmy, Amr H M; Harhash, Tarek A; Ghali, Rami M S; El Maghraby, Eman M F; El Rouby, Dalia H

2017-01-01

The purpose of this study was to compare laser with conventional techniques in class V cavity preparation in gamma-irradiated teeth. Forty extracted human teeth with no carious lesions were used for this study and were divided into two main groups: Group I (n = 20) was not subjected to gamma radiation (control) and Group II (n=20) was subjected to gamma radiation of 60 Gray. Standard class V preparation was performed in buccal and lingual sides of each tooth in both groups. Buccal surfaces were prepared by the Er,Cr:YSGG laser (Waterlase iPlus) 2780 nm, using the gold handpiece with MZ10 Tip in non-contact and the "H" mode, following parameters of cavity preparation - power 6 W, frequency 50 Hz, 90% water and 70% air, then shifting to surface treatment laser parameters - power 4.5 W, frequency 50 Hz, 80% water and 50% air. Lingual surfaces were prepared by the conventional high-speed turbine using round diamond bur. Teeth were then sectioned mesio-distally, resulting in 80 specimens: 40 of which were buccal laser-treated (20 control and 20 gamma-irradiated specimens) and 40 were lingual conventional high-speed bur specimens (20 control and 20 gamma-irradiated specimens). Microleakage analysis revealed higher scores in both gamma groups compared with control groups. Chi-square test revealed no significant difference between both control groups and gamma groups (p=1, 0.819, respectively). A significant difference was revealed between all 4 groups (p=0.00018). Both laser and conventional high-speed turbine bur show good bond strength in control (non-gamma) group, while microleakage is evident in gamma group, indicating that gamma radiation had a dramatic negative effect on the bond strength in both laser and bur-treated teeth.

Biocompatability of compomer restorative systems on nonexposed dental pulps of primate teeth.

PubMed

Tarim, B; Hafez, A A; Suzuki, S H; Suzuki, S; Cox, C F

1997-01-01

This study evaluated the histologic response of total-etched and nonetched compomer restored cavity preparations. One hundred fifteen class 5 cavity preparations were placed in the teeth of four healthy adult monkeys at 7, 27, and 90 days. A 37% H3PO4 was applied for 10 seconds and rinsed in total-etched preparations. No statistical differences were seen in inflammatory reactions among total-etched or nonetched compomers at 7, 27, and 90 days. There were no statistical differences in inflammatory cell responses among all compomer systems in regard to time intervals. Pulpal responses of compomers were greater than IRM at each time period. Pulp responses were associated with stained bacteria in 32 of 89 compomer teeth. No necrotic pulps were seen in any teeth. Statistical data show a positive correlation (P < 0.05) between bacterial presence and pulpal inflammation. IRM pulps showed no inflammation or bacterial staining. Compomers are biologically compatible with pulp tissues when bacteria are excluded.

Quantitative scintigraphic analysis of pulp revascularization in autotransplanted teeth in dogs.

PubMed

Ferreira, Manuel Marques; Botelho, Maria Filomena; Abrantes, Margarida; Oliveiros, Barbara; Carrilho, Eunice Virgínia

2010-11-01

The purpose of this study was to evaluate the pulpal changes associated with autogenous single-rooted immature tooth transplantation in dogs, using either one, or two-stage surgical techniques. Teeth from 3 beagle dogs, 5 months old, were extracted and transplanted to mechanically prepared recipient sockets. Group (A), where the teeth were transplanted using a one-stage method to recipient beds prepared immediately before transplantation. Group (B), where the teeth were transplanted using a two-stage method in which the recipient beds were prepared and left to heal for 7 days before transplantation. Clinical examinations were done every week during 9 weeks. After 9 weeks, the animals were injected with ⁹⁹(m)Technetium hydroxylmethylene diphosphonate (⁹⁹(m)Tc-HMDP) and 3h after injection, a whole body scintigraphic acquisition was performed. After scintigraphic acquisition the animals were euthanized and the teeth extracted and its radioactivity counted in a well counter calibrated to ⁹⁹(m)Tc. With the data obtained, the percentage of activity injected was calculated for each tooth. The data for each group of teeth were evaluated and analyzed using the Mann-Whitney test (p=0.05). All the transplanted teeth in both groups survived. No statistically significant difference was found in the absorption of the ⁹⁹(m)Tc-HMDP, between the treatment groups (p=0.464) and between them and the control group (Group A vs. control p=0.713 and Group B vs. control p=0.157). This study demonstrated that there was no difference between the two surgical techniques in terms of the pulp revascularization in transplanted teeth. Published by Elsevier Ltd.

[Comparative study of the fracture resistance of sound upper premolars and upper premolars restored with bonded amalgam].

PubMed

Minto, André Marcelo Peruchi; Dinelli, Welingtom; Nonaka, Tomio; Thome, Luis Henrique de Camargo

2002-01-01

The purpose of this in vitro study was to determine the fracture resistance of upper premolars which had received class II preparations (conservative and extensive) and were restored with bonded amalgam, with two different adhesive systems. Seventy teeth were divided in four groups: group 1 (control), with ten sound teeth; group 2, with twenty prepared teeth (10 teeth received conservative cavities and 10, extensive cavities) restored with amalgam without any kind of liner; groups 3 and 4, similar to group 2, though with linings of glass ionomer cement (Vitrebond - 3M) (group 3) and dental adhesive (Scotchbond Multi-Purpose Plus - 3M) (group 4). The teeth were previously fixed in PVC cylinders with acrylic resin. After being restored and thermocycled, the test specimens were submitted to fracture by means of compression in an EMIC-MEM 2000 universal testing machine. After the application of the analysis of variance and complementary Tukey's test, we concluded that the utilized adhesive systems produced an increase of the fracture resistance of teeth presenting with conventional cavities; the teeth presenting with conservative cavities were more resistant in all experimental situations.

Class II malocclusion with accentuated occlusal plane inclination corrected with miniplate: a case report

PubMed Central

Farret, Marcel Marchiori; Farret, Milton M. Benitez

2016-01-01

ABSTRACT Introduction: A canted occlusal plane presents an unesthetic element of the smile. The correction of this asymmetry has been typically considered difficult by orthodontists, as it requires complex mechanics and may sometimes even require orthognathic surgery. Objective: This paper outlines the case of a 29-year-old woman with Class II malocclusion, pronounced midline deviation and accentuated occlusal plane inclination caused by mandibular deciduous molar ankylosis. Methods: The patient was treated with a miniplate used to provide anchorage in order to intrude maxillary teeth and extrude mandibular teeth on one side, thus eliminating asymmetry. Class II was corrected on the left side by means of distalization, anchored in the miniplate as well. On the right side, maxillary first premolar was extracted and molar relationship was kept in Class II, while canines were moved to Class I relationship. The patient received implant-prosthetic rehabilitation for maxillary left lateral incisor and mandibular left second premolar. Results: At the end of treatment, Class II was corrected, midlines were matched and the canted occlusal plane was totally corrected, thereby improving smile function and esthetics. PMID:27409658

The Association of Socioeconomic Status and Dental Caries Experience in Children in Dili, Timor-Leste.

PubMed

Babo Soares, Lucio Frederico; Allen, Penny; Bettiol, Silvana; Crocombe, Leonard

2016-10-01

Timor-Leste is one of the poorest countries in the world. The aim of this article was to investigate the association between socioeconomic status (SES) and dental caries experience in children living in Dili. Four out of 6 Dili subdistricts and 40 schools were randomly selected. Equal numbers of school children from 4 age groups (6-8, 9-11, 12-14, 15-17 years) were invited to participate. Data were gathered via a questionnaire and an oral examination by dental practitioners. In bivariate analysis, decayed, missing, and filled teeth index for deciduous + permanent teeth (dmft) was higher in children from mid- to high-SES than low-SES schools (1.1, 2.2, P = .001). With age, having had a toothache and dental visiting in the past 12 months in the multivariable model, higher dmft was found in children from mid- to high- to low-SES schools ( P < .001). The primary dental caries experience was greater among children from mid- to high- than low-SES schools, which may be explained by high sugar consumption.

Root Canal Cleaning Efficacy of Rotary and Hand Files Instrumentation in Primary Molars

PubMed Central

Nazari Moghaddam, Kiumars; Mehran, Majid; Farajian Zadeh, Hamideh

2009-01-01

INTRODUCTION: Pulpectomy of primary teeth is commonly carried out with hand files and broaches; a tricky and time consuming procedure. The purpose of this in vitro study was to compare the cleaning efficacy and time taken for instrumentation of deciduous molars using hand K-files and Flex Master rotary system. MATERIALS AND METHODS: In this study, 68 canals of 23 extracted primary molars with at least two third intact roots and 7-12 mm length were selected. After preparing an access cavity, K-file size #15 was introduced into the root canal and India ink was injected with an insulin syringe. Sixty samples were randomly divided in to experimental groups in group I (n=30), root canals were prepared with hand K-files; in group II (n=30), rotary Flex Master files were used for instrumentation, and in group III 8 remained samples were considered as negative controls. After clearing and root sectioning, the removal of India ink from cervical, middle, and apical thirds was scored. Data was analyzed using student's T-test and Mann-Whitney U test. RESULTS: There was no significant difference between experimental groups cleaning efficacy at the cervical, middle and apical root canal thirds. Only the coronal third scored higher in the hand instrumented group (P<0.001). Instrumentation with Flex Master rotary files was significantly less time consuming (P<0.001). CONCLUSION: Although there was no difference in cleanliness efficacy at the apical and middle thirds, the coronal third was more effectively cleaned with hand files. Predictably, time efficiency was a significant advantage with rotary technique. PMID:23940486

Relationship between the Apical Preparation Diameter and the Apical Seal: An In Vitro Study.

PubMed

Laslami, Kaoutar; Dhoum, Sara; El Harchi, Amine; Benkiran, Iman

2018-01-01

The aim of the study is to define the relationship between the apical preparation diameter and the apical sealing ability to highlight the importance of the preservation of the diameter and the original position of the apical foramen. 50 extracted maxillary incisors were randomly allocated into three groups of 15 teeth each (n = 15) according to the apical preparation size: Group 1: finishing file F1 corresponding to size 20 reached the working length (ProTaper Universal system Dentsply®); Group 2: prepared up to size 30 corresponding to finishing file F30; Group 3: prepared up to size 50 corresponding to finishing file F5. Five teeth were assigned to positive and negative control groups. After the filling of the root canals, the teeth were isolated and immersed in a dye solution, then cut longitudinally, photographed, and the dye penetration were calculated using a computer software. Comparison of the three different apical preparation sizes showed no statistically significant differences regarding the apical microleakage. The most important value of the dye penetration was observed in the group with the largest apical diameter.

Dynamic Alterations in Salivary Microbiota Related to Dental Caries and Age in Preschool Children With Deciduous Dentition: A 2-Year Follow-Up Study

PubMed Central

Xu, Lei; Chen, Xi; Wang, Yuan; Jiang, Wen; Wang, Sa; Ling, Zongxin; Chen, Hui

2018-01-01

Dynamic alterations in oral microbiota are closely related to the development of dental caries;however, changes in salivary microbiota during this process have not been extensively studied. In addition, increasing evidence suggests that oral microbiome profiles differ according to dentition stages, but it is unclear whether they change with age during the same dentition, such as deciduous dentition. These two aspects were investigated in a 2-year follow-up study, and caries-free preschool children with complete deciduous dentition were enrolled. Saliva was collected and oral examination was conducted at the beginning of this trial, and then every subsequent 6 months for a total of five time points (T0, T1, T2, T3, and T4). Based on the clinical examination of teeth at the end of the trial, subjects were divided into health-to-health (H-H, N = 11) and health-to-caries (H-C, N = 12) groups at every time point. A total of 115 saliva samples from 23 subjects was detected by sequencing 16S rDNA V3-V4 hypervariable regions with the Illumina MiSeq platform to obtain microbiome profiles, and 100 samples finally passed quality control for further analyses. A total of 4,328,852 high-quality sequencing reads passed quality-control testing, representing 14 phyla, 27 classes, 43 orders, 67 families, and 127 genera. An α diversity analysis showed that salivary microbial diversity was similar in all groups, and a β diversity analysis showed that salivary microbial community structure changed with dental caries. Linear discriminant analysis effect size (LEfSe) analysis revealed that the abundance of the genera Atopobium, Megasphaera, and Veillonella increased significantly, while that of the genera Shuttleworthia and Rothia decreased significantly with the development of dental caries. Megasphaera and Veillonella were enriched at the early stage of deciduous dentition whereas Peptococcus, Rothia, and Treponema were enriched at the later stage. The core microbiome in the H-H and H-C groups comprised 26 and 29 genera, respectively, with statistical differences observed in 11 shared core genera. These results provide new insights into variations in the salivary microbiome related to dental caries and age in the deciduous dentition period. PMID:29670544

Dynamic Alterations in Salivary Microbiota Related to Dental Caries and Age in Preschool Children With Deciduous Dentition: A 2-Year Follow-Up Study.

PubMed

Xu, Lei; Chen, Xi; Wang, Yuan; Jiang, Wen; Wang, Sa; Ling, Zongxin; Chen, Hui

2018-01-01

Dynamic alterations in oral microbiota are closely related to the development of dental caries;however, changes in salivary microbiota during this process have not been extensively studied. In addition, increasing evidence suggests that oral microbiome profiles differ according to dentition stages, but it is unclear whether they change with age during the same dentition, such as deciduous dentition. These two aspects were investigated in a 2-year follow-up study, and caries-free preschool children with complete deciduous dentition were enrolled. Saliva was collected and oral examination was conducted at the beginning of this trial, and then every subsequent 6 months for a total of five time points (T0, T1, T2, T3, and T4). Based on the clinical examination of teeth at the end of the trial, subjects were divided into health-to-health (H-H, N = 11) and health-to-caries (H-C, N = 12) groups at every time point. A total of 115 saliva samples from 23 subjects was detected by sequencing 16S rDNA V3-V4 hypervariable regions with the Illumina MiSeq platform to obtain microbiome profiles, and 100 samples finally passed quality control for further analyses. A total of 4,328,852 high-quality sequencing reads passed quality-control testing, representing 14 phyla, 27 classes, 43 orders, 67 families, and 127 genera. An α diversity analysis showed that salivary microbial diversity was similar in all groups, and a β diversity analysis showed that salivary microbial community structure changed with dental caries. Linear discriminant analysis effect size (LEfSe) analysis revealed that the abundance of the genera Atopobium, Megasphaera , and Veillonella increased significantly, while that of the genera Shuttleworthia and Rothia decreased significantly with the development of dental caries. Megasphaera and Veillonella were enriched at the early stage of deciduous dentition whereas Peptococcus, Rothia , and Treponema were enriched at the later stage. The core microbiome in the H-H and H-C groups comprised 26 and 29 genera, respectively, with statistical differences observed in 11 shared core genera. These results provide new insights into variations in the salivary microbiome related to dental caries and age in the deciduous dentition period.

Influence of the Apical Preparation Size and the Irrigant Type on Bacterial Reduction in Root Canal-treated Teeth with Apical Periodontitis.

PubMed

Rodrigues, Renata Costa Val; Zandi, Homan; Kristoffersen, Anne Karin; Enersen, Morten; Mdala, Ibrahimu; Ørstavik, Dag; Rôças, Isabela N; Siqueira, José F

2017-07-01

This clinical study evaluated the influence of the apical preparation size using nickel-titanium rotary instrumentation and the effect of a disinfectant on bacterial reduction in root canal-treated teeth with apical periodontitis. Forty-three teeth with posttreatment apical periodontitis were selected for retreatment. Teeth were randomly divided into 2 groups according to the irrigant used (2.5% sodium hypochlorite [NaOCl], n = 22; saline, n = 21). Canals were prepared with the Twisted File Adaptive (TFA) system (SybronEndo, Orange, CA). Bacteriological samples were taken before preparation (S1), after using the first instrument (S2), and then after the third instrument of the TFA system (S3). In the saline group, an additional sample was taken after final irrigation with 1% NaOCl (S4). DNA was extracted from the clinical samples and subjected to quantitative real-time polymerase chain reaction to evaluate the levels of total bacteria and streptococci. S1 from all teeth were positive for bacteria. Preparation to the first and third instruments from the TFA system showed a highly significant intracanal bacterial reduction regardless of the irrigant (P < .01). Apical enlargement to the third instrument caused a significantly higher decrease in bacterial counts than the first instrument (P < .01). Intergroup comparison revealed no significant difference between NaOCl and saline after the first instrument (P > .05). NaOCl was significantly better than saline after using the largest instrument in the series (P < .01). Irrespective of the type of irrigant, an increase in the apical preparation size significantly enhanced root canal disinfection. The disinfecting benefit of NaOCl over saline was significant at large apical preparation sizes. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The effect of root canal preparation on the development of dentin cracks.

PubMed

Milani, Amin Salem; Froughreyhani, Mohammad; Rahimi, Saeed; Jafarabadi, Mohammad Asghari; Paksefat, Sara

2012-01-01

Root fracture is not an instant phenomenon but a result of gradual development of tiny craze lines in tooth structure. Recent studies have shown that canal instrumentation has the potential to cause dentinal cracks. The purpose of this study was to evaluate and compare the formation of dentinal cracks caused by ProTaper rotary system to hand instrumentation. This in vitro study was carried out using 57 mandible incisor teeth. The teeth were decoronated. The roots were then examined to exclude cracked samples. A standard model for PDL simulation was used. The teeth were randomly divided into two experimental and one control group (n=19). The teeth in the experimental groups were prepared using hand or ProTaper Universal rotary instrumentation. The teeth in the control group were left unprepared. The teeth were then sectioned horizontally 3 and 6 mm from the apex, and the number of various dentinal defects was recorded using a dental operating microscope. The differences between groups were analyzed with Fisher's exact test. The hand group demonstrated significantly more defects than the control group (P=0.001). However, there was no significant difference between the rotary compared to the control and hand groups (P>0.05). There was no significant difference between groups with regards to fracture (P>0.05). Other defects including internal, external and surface cracks were more frequent in the hand than in the control or rotary groups (P=0.02), but the difference was not significant between the rotary and control groups (P>0.05). Canal preparation, whether hand or rotary, produces structural defects in dentin. The ProTaper rotary system when used according to the manufacturer's instructions, tends to produce fewer cracks and can be considered a safe preparation technique.

Clinical Characteristics of Abutment Teeth with Gingival Discoloration.

PubMed

Ristic, Ljubisa; Dakovic, Dragana; Postic, Srdjan; Lazic, Zoran; Bacevic, Miljana; Vucevic, Dragana

2017-04-06

The grey-bluish discoloration of gingiva (known as "amalgam tattoo") does not appear only in the presence of amalgam restorations. It may also be seen in cases of teeth restored with cast dowels and porcelain-fused-to-metal (PFM) restorations. The aim of this article was to determine the clinical characteristics of abutment teeth with gingival discoloration. This research was conducted on 25 patients referred for cast dowel and PFM restorations. These restorations were manufactured from Ni-Cr alloys. Ninety days after cementing the fixed prosthodontic restorations, the abutment teeth (n = 61) were divided into a group with gingival discoloration (GD) (n = 25) and without gingival discoloration (NGD) (n = 36). The control group (CG) comprised the contralateral teeth (n = 61). Plaque index, gingival index, clinical attachment level, and probing depth were assessed before fabrication and also 90 days after cementation of the PFM restorations. The gingival index, clinical attachment level, and probing depths of the abutment teeth that had GD were statistically higher before restoration, in comparison with the abutment teeth in the NGD and control groups. Ninety days after cementation, the abutment teeth with GD had significantly lower gingival indexes and probing depths, compared to the abutment teeth in the NGD group. Both abutment teeth groups (GD and NGD) had significantly higher values of clinical attachment levels when compared to the control group. There were no statistically significant differences in plaque index values between the study groups. The results of this study indicated that impairment of periodontal status of abutment teeth seemed to be related to the presence of gingival discolorations. Therefore, fabrication of fixed prosthodontic restorations requires careful planning and abutment teeth preparation to minimize the occurrence of gingival discolorations. With careful preparation of abutment teeth for cast dowels and crown restorations it may be possible to decrease the frequency of gingival discolorations adjacent to abutment teeth. © 2017 by the American College of Prosthodontists.

Broad gap junction blocker carbenoxolone disrupts uterine preparation for embryo implantation in mice.

PubMed

Diao, Honglu; Xiao, Shuo; Howerth, Elizabeth W; Zhao, Fei; Li, Rong; Ard, Mary B; Ye, Xiaoqin

2013-08-01

Gap junctions have an important role in cell-to-cell communication, a process obviously required for embryo implantation. Uterine luminal epithelium (LE) is the first contact for an implanting embryo and is critical for the establishment of uterine receptivity. Microarray analysis of the LE from peri-implantation mouse uterus showed low-level expression of 19 gap junction proteins in preimplantation LE and upregulation of gap junction protein, beta 2 (GJB2, connexin 26, Cx26) in postimplantation LE. Time course study using in situ hybridization and immunofluorescence revealed upregulation of GJB2 in the LE surrounding the implantation site before decidualization. Similar dynamic expression of GJB2 was observed in the LE of artificially decidualized mice but not pseudopregnant mice. To determine the potential function of uterine gap junctions in embryo implantation, carbenoxolone (CBX), a broad gap junction blocker, was injected i.p. (100 mg/kg) or via local uterine fat pad (10 mg/kg) into pregnant mice on Gestation Day 3 at 1800 h, a few hours before embryo attachment to the LE. These CBX treatments disrupted embryo implantation, suggesting local effects of CBX in the uterus. However, i.p. injection of glycyrrhizic acid (100 mg/kg), which shares similar structure and multiple properties with CBX but is ineffective in blocking gap junctions, did not affect embryo implantation. Carbenoxolone also inhibited oil-induced artificial decidualization, concomitant with suppressed molecular changes and ultrastructural transformations associated with uterine preparation for embryo implantation, underscoring the adverse effect of CBX on uterine preparation for embryo implantation. These data demonstrate that uterine gap junctions are important for embryo implantation.

Standards of teeth preparations for anterior resin bonded all-ceramic crowns in private dental practice in Jordan

PubMed Central

AL-DWAIRI, Ziad Nawaf; AL-HIYASAT, Ahmad Saleh; ABOUD, Haitham

2011-01-01

Objectives To investigate if general dental practitioners (GDPs) in private practice in Jordan follow universal guidelines for preparation of anterior teeth for resin bonded all-ceramic crowns (RBCs). Material and Methods A sample (n=100) of laboratory models containing 208 tooth preparations for IPS Empress and In Ceram, featuring work from different GDPs, was obtained from 8 commercial dental laboratories. Aspects of preparations were quantified and compared with accepted criteria defined following a review of the literature and recommendations of the manufactures' guidelines. Results Subgingival margins on the buccal aspect were noticed in 36% of the preparations, 54% demonstrated overpreparation with a tendency to overprepare the teeth on the mesiodistal plane more than buccolingual plane. Twenty percent of samples presented a shoulder finish line while a chamfer margin design was noticed in 39%. Twenty-nine percent and 12% of samples had either a feathered or no clear margin design respectively. Incisal under preparation was observed in 18% of dies of each type. Only 17% of all preparations were found to follow the recommended anatomical labial preparations while 29% of the RBC preparations were found to have the recommended axial convergence angle. In total, 43% of preparations were found to have the recommended depth of the finish line. Conclusions It was found that relevant guidelines for RBC preparations were not being fully adhered to in private practice in Jordan. PMID:21710098

Comparison of Amount of Primary Tooth Reduction Required for Anterior and Posterior Zirconia and Stainless Steel Crowns.

PubMed

Clark, Larkin; Wells, Martha H; Harris, Edward F; Lou, Jennifer

2016-01-01

To determine if aggressiveness of primary tooth preparation varied among different brands of zirconia and stainless steel (SSC) crowns. One hundred primary typodont teeth were divided into five groups (10 posterior and 10 anterior) and assigned to: Cheng Crowns (CC); EZ Pedo (EZP); Kinder Krowns (KKZ); NuSmile (NSZ); and SSC. Teeth were prepared, and assigned crowns were fitted. Teeth were weighed prior to and after preparation. Weight changes served as a surrogate measure of tooth reduction. Analysis of variance showed a significant difference in tooth reduction among brand/type for both the anterior and posterior. Tukey's honest significant difference test (HSD), when applied to anterior data, revealed that SSCs required significantly less tooth removal compared to the composite of the four zirconia brands, which showed no significant difference among them. Tukey's HSD test, applied to posterior data, revealed that CC required significantly greater removal of crown structure, while EZP, KKZ, and NSZ were statistically equivalent, and SSCs required significantly less removal. Zirconia crowns required more tooth reduction than stainless steel crowns for primary anterior and posterior teeth. Tooth reduction for anterior zirconia crowns was equivalent among brands. For posterior teeth, reduction for three brands (EZ Pedo, Kinder Krowns, NuSmile) did not differ, while Cheng Crowns required more reduction.

Shear Bond Strength of Self-etching Adhesives to Cavities Prepared by Diamond Bur or Er,Cr:YSGG Laser and Effect of Prior Acid Etching.

PubMed

Jhingan, Pulkit; Sachdev, Vinod; Sandhu, Meera; Sharma, Karan

2015-12-01

To compare and evaluate shear bond strength of self-etching adhesives bonded to cavities prepared by diamond bur or Er,Cr:YSGG laser and the effect of prior acid etching on shear bond strength. Ninety-six caries-free human premolars were selected and divided into 2 groups depending on mode of cavity preparation (48 teeth each). Cavities were prepared with Er,Cr:YSGG laser in group 1 and diamond burs in an air-turbine handpiece in group 2. Groups 1 and 2 were further subdivided into three subgroups of 8 teeth each, which were bonded with sixth- or seventh-generation adhesives with or without prior acid etching, followed by restoration of all samples with APX Flow. These samples were subjected to shear bond strength testing. In addition, the surface morphology of 24 samples each from groups 1 and 2 was evaluated using SEM. Data were analyzed using the Shapiro-Wilk test, one- and two-way ANOVA, the t-test, and the least significant difference test, which showed that the data were normally distributed (p > 0.05). The shear bond strength of adhesives in cavities prepared by Er,Cr:YSGG laser was significantly higher than in diamond bur-prepared cavities (p < 0.05). SEM analysis showed a smear-layer-free anfractuous surface on laser-ablated teeth, in contrast to conventional bur-prepared teeth. The Er,Cr:YSGG laser-ablated surface proved to be more receptive for adhesion than those prepared by diamond bur irrespective of the bonding agent used. Seventh-generation adhesives yielded higher shear bond strength than did sixth-generation adhesives. Prior acid etching decreased the shear bond strength of self-etching adhesives.

Fracture resistance of five pin-retained core build-up materials on teeth with and without extracoronal preparation.

PubMed

Burke, F J; Shaglouf, A G; Combe, E C; Wilson, N H

2000-01-01

Core build-ups should provide satisfactory strength and resistance to fracture both before and after crown preparation. This paper examines the resistance to fracture of core build-ups in different materials and the fracture resistance of core build-ups when these have been reduced for full crown preparation. Standardized core build-ups were made on groups of extracted molar teeth of similar size, with 10 teeth per group. Three resin-composite (prisma APH: Dentsply, Weybridge, UK; Ti-Core, Essential Dental Systems, NJ, US and Coradent, Vivadent, Liechtenstein), one cermet (Ketac-Silver, ESPE GmbH, Seefeld, Germany) and one amalgam material (Duralloy, Degussa Ltd, Cheshire, UK). These specimens were subjected to compressive force on a universal testing machine and the force at fracture noted. Standardized full crown preparations were made on a further five groups of core build-up specimens using the same materials as above. These prepared specimens were subjected to compressive force on a universal testing machine and the force to fracture noted. The results indicated that amalgam core build-ups demonstrated higher fracture resistance than the other materials examined. There was a general decrease in the fracture strength of the specimens following crown preparation, with the teeth restored with the amalgam core build-ups showing a greater percentage reduction in fracture strength than the other materials tested. Prepared core build-ups in a hybrid composite material provided the highest fracture resistance. The cermet material used provided the lowest resistance to fracture in both the core build-up and crown preparation specimens. In terms of fracture resistance, no advantage was apparent in using the two composite materials designated as being specifically appropriate for core build-ups.

Low-level laser irradiation induces in vitro proliferation of stem cells from human exfoliated deciduous teeth.

PubMed

Ginani, Fernanda; Soares, Diego Moura; de Oliveira Rocha, Hugo Alexandre; de Souza, Lélia Batista; Barboza, Carlos Augusto Galvão

2018-01-01

The aim of this study was to evaluate the effect of low-level laser irradiation (LLLI) on the proliferation and viability of stem cells from human exfoliated deciduous teeth (SHED). Cells were irradiated or not (control) with an InGaAlP laser diode (660 nm, 30 mW, continuous action mode) using two different energy densities (0.5 J/cm 2 -16 s; 1.0 J/cm 2 -33 s). Irradiation was performed at 0 and 48 h, with the laser probe fixed at a distance of 0.5 cm from the cells. Cell proliferation was analyzed at 0, 24, 48, and 72 h by the Trypan blue exclusion method and MTT assay. Cell cycle and Ki67 expression were analyzed by flow cytometry. Apoptosis-related events were evaluated by expression of annexin V/PI and nuclear morphological changes by staining with DAPI. Differences between groups at each time were analyzed by the Kruskal-Wallis and Mann-Whitney tests, adopting a level of significance of 5% (p < 0.05). The results showed that an energy density of 1.0 J/cm 2 promoted an increase in cell proliferation at 48 and 72 h compared to the control and 0.5 J/cm 2 groups. Cell cycle analysis revealed a predominance of cells in the S and G2/M phases in the irradiated groups. This finding was confirmed by the increased expression of Ki67. Low positive staining for annexin V and PI was observed in all groups, and no nuclear changes were detected, indicating that cell viability was not affected by the energy densities tested. It can be concluded that the LLLI parameters used (660 nm, 30 mW, 1.0 J/cm 2 ) promote the proliferation of SHEDs and the maintenance of cell viability.

Transcriptome comparison of human neurons generated using induced pluripotent stem cells derived from dental pulp and skin fibroblasts.

PubMed

Chen, Jian; Lin, Mingyan; Foxe, John J; Pedrosa, Erika; Hrabovsky, Anastasia; Carroll, Reed; Zheng, Deyou; Lachman, Herbert M

2013-01-01

Induced pluripotent stem cell (iPSC) technology is providing an opportunity to study neuropsychiatric disorders through the capacity to grow patient-specific neurons in vitro. Skin fibroblasts obtained by biopsy have been the most reliable source of cells for reprogramming. However, using other somatic cells obtained by less invasive means would be ideal, especially in children with autism spectrum disorders (ASD) and other neurodevelopmental conditions. In addition to fibroblasts, iPSCs have been developed from cord blood, lymphocytes, hair keratinocytes, and dental pulp from deciduous teeth. Of these, dental pulp would be a good source for neurodevelopmental disorders in children because obtaining material is non-invasive. We investigated its suitability for disease modeling by carrying out gene expression profiling, using RNA-seq, on differentiated neurons derived from iPSCs made from dental pulp extracted from deciduous teeth (T-iPSCs) and fibroblasts (F-iPSCs). This is the first RNA-seq analysis comparing gene expression profiles in neurons derived from iPSCs made from different somatic cells. For the most part, gene expression profiles were quite similar with only 329 genes showing differential expression at a nominally significant p-value (p<0.05), of which 63 remained significant after correcting for genome-wide analysis (FDR <0.05). The most striking difference was the lower level of expression detected for numerous members of the all four HOX gene families in neurons derived from T-iPSCs. In addition, an increased level of expression was seen for several transcription factors expressed in the developing forebrain (FOXP2, OTX1, and LHX2, for example). Overall, pathway analysis revealed that differentially expressed genes that showed higher levels of expression in neurons derived from T-iPSCs were enriched for genes implicated in schizophrenia (SZ). The findings suggest that neurons derived from T-iPSCs are suitable for disease-modeling neuropsychiatric disorder and may have some advantages over those derived from F-iPSCs.

Comparative characterization of stem cells from human exfoliated deciduous teeth, dental pulp, and bone marrow-derived mesenchymal stem cells.

PubMed

Kunimatsu, Ryo; Nakajima, Kengo; Awada, Tetsuya; Tsuka, Yuji; Abe, Takaharu; Ando, Kazuyo; Hiraki, Tomoka; Kimura, Aya; Tanimoto, Kotaro

2018-06-18

Mesenchymal stem cells (MSCs) are used clinically in tissue engineering and regenerative medicine. The proliferation and osteogenic differentiation potential of MSCs vary according to factors such as tissue source and cell population heterogeneity. Dental tissue has received attention as an easily accessible source of high-quality stem cells. In this study, we compared the in vitro characteristics of dental pulp stem cells from deciduous teeth (SHED), human dental pulp stem cells (hDPSCs), and human bone marrow mesenchymal stem cells (hBMSCs). SEHD and hDPSCs were isolated from dental pulp and analyzed in comparison with human bone marrow (hBM)MSCs. Proliferative capacity of cultured cells was analyzed using a bromodeoxyuridine immunoassay and cell counting. Alkaline phosphatase (ALP) levels were monitored to assess osteogenic differentiation. Mineralization was evaluated by alizarin red staining. Levels of bone marker mRNA were examined by real-time PCR analysis. SHED were highly proliferative compared with hDPSCs and hBMSCs. SHED, hDPSCs, and hBMSCs exhibited dark alizarin red staining on day 21 after induction of osteogenic differentiation, and staining of hBMSCs was significantly higher than that of SHED and hDPSCs by spectrophotometry. ALP staining was stronger in hBMSCs compared with SHED and hDPSCs, and ALP activity was significantly higher in hBMSCs compared with SHED or hDPSCs. SHED showed significantly higher expression of the Runx2 and ALP genes compared with hBMSCs, based on real-time PCR analysis. In bFGF, SHED showed significantly higher expression of the basic fibroblast growth factor (bFGF) gene compared with hDPSCs and hBMSCs. SHED exhibited higher proliferative activity and levels of bFGF and BMP-2 gene expression compared with BMMSCs and DPSCs. The ease of harvesting cells and ability to avoid invasive surgical procedures suggest that SHED may be a useful cell source for application in bone regeneration treatments. Copyright © 2018 Elsevier Inc. All rights reserved.

Comparison of the bone regeneration ability between stem cells from human exfoliated deciduous teeth, human dental pulp stem cells and human bone marrow mesenchymal stem cells.

PubMed

Nakajima, Kengo; Kunimatsu, Ryo; Ando, Kazuyo; Ando, Toshinori; Hayashi, Yoko; Kihara, Takuya; Hiraki, Tomoka; Tsuka, Yuji; Abe, Takaharu; Kaku, Masato; Nikawa, Hiroki; Takata, Takashi; Tanne, Kazuo; Tanimoto, Kotaro

2018-03-11

Cleft lip and palate is the most common congenital anomaly in the orofacial region. Autogenous iliac bone graft, in general, has been employed for closing the bone defect at the alveolar cleft. However, such iliac bone graft provides patients with substantial surgical and psychological invasions. Consequently, development of a less invasive method has been highly anticipated. Stem cells from human exfoliated deciduous teeth (SHED) are a major candidate for playing a significant role in tissue engineering and regenerative medicine. The aim of this study was to elucidate the nature of bone regeneration by SHED as compared to that of human dental pulp stem cells (hDPSCs) and bone marrow mesenchymal stem cells (hBMSCs). The stems cells derived from pulp tissues and bone marrow were transplanted with a polylactic-coglycolic acid barrier membrane as a scaffold, for use in bone regeneration in an artificial bone defect of 4 mm in diameter in the calvaria of immunodeficient mice. Three-dimensional analysis using micro CT and histological evaluation were performed. Degree of bone regeneration with SHED relative to the bone defect was almost equivalent to that with hDPSCs and hBMSCs 12 weeks after transplantation. The ratio of new bone formation relative to the pre-created bone defect was not significantly different among groups with SHED, hDPSCs and hBMSCs. In addition, as a result of histological evaluation, SHED produced the largest osteoid and widely distributed collagen fibers compared to hDPSCs and hBMSCs groups. Thus, SHED transplantation exerted bone regeneration ability sufficient for the repair of bone defect. The present study has demonstrated that SHED is one of the best candidate as a cell source for the reconstruction of alveolar cleft due to the bone regeneration ability with less surgical invasion. Copyright © 2018 Elsevier Inc. All rights reserved.

Parent's pro-health awareness concerning oral health of their children in the light of survey research.

PubMed

Wapniarska, Karolina; Buła, Katarzyna; Hilt, Aleksandra

2016-01-01

Oral hygiene is a crucial part of caring for young children. This problem is frequently marginalized or even ignored by parents/guardians, what affects child's whole further life. The assessment of parents' knowledge concerning oral hygiene and prevention of dental caries in infants and young children. The test group consisted of parents, as well as men and women currently expecting a child. The study was conducted in a form of a survey, using an original questionnaire, which was carried out in several hospitals in Lodz and online, on a popular local forum for parents. The data obtained were analyzed statistically, allowing the assessment of health awareness of respondents and the creation of various profiles of parental knowledge on the subject investigated. Most of respondents knew the age at which milk and permanent teeth erupt, gave the correct frequency of brushing child's teeth and were in favor of limiting sweets in the diet. A total of 59% correctly gave the number of deciduous teeth and 66% had heard of the "bottle tooth decay". All respondents thought that helping and controlling a child while brushing their teeth is indispensable, but they did not know the best time to start using the toothpaste with fluoride. The information about child's oral hygiene was more often looked for by women (67%) than by men (29%). The study also showed that if a training on the given subject was organized, 60% of respondents would be willing to participate in it. In the test group, pro-health awareness is insufficient to maintain the oral health of the offspring and requires constant developing.

Short stature Revealing a Pycnodysostosis: A Case Report

PubMed Central

Aynaou, Hayat; Skiker, Imane; Latrech, Hanane

2016-01-01

Introduction: Pycnodysostosis is a rare genetic disease characterized by osteosclerosis and bone fragility. The clinical aspects are varied including short stature, acro-osteolysis of distal phalanges, and dysplasia of the clavicles. Oral and maxillofacial manifestations of this disease are very clear. The head is usually large, a beaked nose, obtuse mandibular angle, and both maxilla and mandible are hypoplastic. Dental abnormalities are common. We report a case with the typical clinical and radiological characteristics of the Pycnodysostosis associated with a conductive hearing loss, an association rarely reported. Case Presentation: A 12-year-female was admitted in our institute for short stature with a dysmorphic facies for evaluation. The patient reported a history of multiple fractures of the long bones after a trivial fall. On physical examination, she had the following features: short stature, limited mouth opening, short hands and feet with dysplastic nails; frontal and occipital bossing; and hypoplasia of the maxilla and mandible. Examination of the mouth: grooved palate, caries of the teeth, impacted and malposed teeth, persistent deciduous teeth and missing teeth. Laboratory investigations were normal. The radiographic examination showed a generalized increase in the bone density, slight condensation of the skull base and a very open mandibular angle. X-rays showed tapered phalanges with acro-osteolysis of the distal phalanges. A symptomatic treatment was proposed based on fracture prevention, oral hygiene, frequent dental visits and psychiatric support. Conclusion: The clinical and radiological features are the bases for the diagnosis of this disease. It is important to make the diagnosis as early as possible in order to plan the treatment and to provide a better life quality to the patients. PMID:27703936

Tunnel restorations using glass ionomer or glass cermet: in vitro marginal ridge fracture and microleakage.

PubMed

Shetty, R; Munshi, A K

1996-01-01

The purpose of this in vitro study was to compare the marginal ridge fracture resistance and microleakage following restorations of partial tunnel preparations using glass ionomer and glass cermet cements. Sixty eight sound premolars were selected for this study and were divided randomly into six groups. A standardized partial tunnel preparation was done on all the teeth except specimens belonging to Group I. The partial tunnel preparations of Groups III & V were restored with glass ionomer and that of Groups IV & VI were restored with glass cermet. The teeth belonging to Groups I, II, III & IV were subjected to marginal ridge fracture resistance testing. The teeth of Groups V & VI were tested for microleakage after immersing them in 5% methylene blue solution for 4 hours. The results indicated that the teeth restored with glass cermet were marginally better than that with glass ionomer in terms of marginal ridge fracture resistance. Both the materials failed to reinforce the marginal ridge to the level of an intact tooth. The microleakage which occurred around both the materials were statistically insignificant, but on comparison glass ionomer showed better results. Hence, glass ionomer is preferred as a restorative material for partial tunnel preparations because of additional inherent advantages like superior esthetics and fluoride leachability.

Does dental health of 6-year-olds reflect the reform of the Israeli dental care system?

PubMed

Natapov, Lena; Sasson, Avi; Zusman, Shlomo P

2016-01-01

The National health insurance law enacted in 1995 did not include dental care in its basket of services. Dental care for children was first included in 2010, initially up till 8 years of age. The eligibility age rose to 12 years in 2013. The dental survey of 6 year-olds in 2007 found that the average of decayed, missing and filled teeth index (dmft) was 3.31 and 35 % of children were caries free. The current cross sectional survey of dental health for 6 year-olds was conducted as a comparison to the pre-reform status. Twenty-three local authorities were randomly selected nationwide. Two Grade 1 classes were randomly chosen in each. The city of Jerusalem was also included in the survey because of its size. The children were examined according to the WHO Oral Health Survey Methods 4th ed protocol. The dental caries index for deciduous teeth (dmft: decayed, missing, filled teeth) was calculated. One thousand two hundred ten children were examined. 61.7 % of the children suffered from dental decay and only 38.3 % were caries free. The mean dmft was 2.56; d = 1.41 (teeth with untreated caries), f = 1.15 (teeth damaged by decay and restored), virtually none were missing due to caries. Dental caries prevalence was rather consistent, an average of over 2 teeth affected per child. Although there is no major change in comparison to former surveys, there is more treated than untreated disease. In the present survey the f component is higher than in the past, especially in the Jewish sector where it is the main component. It is still lower in the Arab sector. Although the level of dental disease remained rather constant, an increase in the treatment component was observed. In order to reduce caries prevalence, preventive measures such as school dental services and drinking water fluoridation should be extended and continued. Primary preventive dental services should be established for children from birth, with an emphasis on primary health care and educational settings, such as family health centers and kindergartens.

A Histopathological Comparison of Pulpal Response to Chitra-CPC and Formocresol used as Pulpotomy Agents in Primary Teeth: A Clinical Trial

PubMed Central

Thomas, Bijimol

2012-01-01

ABSTRACT Preventive measures have helped to minimize the occurrence of dental caries. However, premature loss of primary teeth on account of dental caries still remains a common problem among children. The pulpotomy technique has been the choice for treating vital primary and young permanent teeth with carious, mechanical and traumatic pulp exposures. The ideal pulpotomy medicament should be bioinductive or at least biocompatible, bactericidal and harmless to the pulp and surrounding structures. It should also promote healing of the radicular pulp and prevent bacterial microleakage with the least interference in the physiological process of root resorption. Since the best criteria for judging the effectiveness of a medicament when used for vital pulp therapy is the response that it produces in the pulp. The purpose of the present study was to evaluate and compare the response of human pulp tissue to recently developed Indian material, Sree Chitra-Calcium Phosphate Cement (Chitra-CPC) and formocresol, used as pulpotomy agent in deciduous teeth. Chitra-CPC has been compared with formocresol, taking into account that formocresol is still considered the gold standard in primary tooth pulpotomy. The study was conducted among 10 children in the age group of 8 to 12 years focusing on 20 noncarious primary canines indicated for serial extraction. Each patient received two different pulpotomy procedures—one in each of the primary canines using formocresol and the other with Chitra-CPC as pulpotomy agents. After 70 days, the teeth were extracted and subjected to histological examination. The results did not reveal statistically significant difference between the two groups. But Chitra-CPC gave more favorable results, in respect of pulpal inflammation, dentin bridge formation, quality of dentin bridge and connective tissue in dentin bridge. How to cite this article: Ratnakumari N, Thomas B. A Histopathological Comparison of Pulpal Response to Chitra- CPC and Formocresol used as Pulpotomy Agents in Primary Teeth: A Clinical Trial. Int J Clin Pediatr Dent 2012;5(1):6-13. PMID:25206127

Cleaning and shaping curved root canals: Mtwo vs ProTaper instruments, a lab comparison.

PubMed

Kuzekanani, Maryam; Walsh, Laurence J; Yousefi, Mohammad Ali

2009-01-01

The purpose of this study was to compare root canal preparation in curved canals in molar teeth with the rotary NiTi Mtwo and ProTaper systems in terms of canal shape and smear layer. Mesiobuccal canals of 60 molar teeth with angles of curvature between 25 and 35 degrees were prepared with a torque controlled low speed engine; 30 canals for each system. Each individual instrument was used to prepare four root canals and the time required for preparation was recorded. Standardized radiographs were taken before and following instrumentation and used to determine changes in canal curvature. There was no significant difference in preparation time between the two systems. No instruments separated during use. The Mtwo system gave a statistically smaller change in canal curvature and thus was better for maintaining the original shape of the root canal, with less transportation (P less than 0.05). The greatest difference was seen for maxillary molar teeth. When prepared root canals were examined by SEM there was no difference between the two systems at the coronal, middle or apical thirds. Overall, the results of this study suggest that Mtwo instruments are preferable for situations where canals are curved, particularly for maxillary molars.

Comparative evaluation of microleakage of a carbomer/fluoroapatite-enhanced glass-ionomer cement on primary teeth restorations.

PubMed

Tolidis, K; Boutsiouki, C; Gerasimou, P

2016-09-01

Carbomer cement represents a novel glass-ionomer which gradually mineralises into fluoroapatite. Purpose of this study was to evaluate microleakage around restorations in deciduous teeth made with composite resin, conventional glass-ionomer cement, resin-modified glass-ionomer cement and carbomer/fluoroapatite-enhanced glass-ionomer cement. A group of 40 primary upper canines, primary upper and lower molars was divided into 4 groups (n=10). Class I cavities were prepared by diamond cylindrical bur at high speed and were restored with a composite resin (Group 1), with a glass- ionomer cement (Group 2), with a resin-modified glass-ionomer cement (Group 3) and with a carbomer/fluoroapatite-enhanced glass- ionomer cement (Group 4). Hard tissue's bonding involved, in the case of composite resin a total etch bonding procedure, and in glass ionomers the use of their respective primers. Restorations were finished and polished. A 24-hour water storage was followed by thermocycling (1500 cycles, 5°C - 36°C - 55°C - 36°C with a dwell time of 15 seconds) and dye penetration test with immersion in 5% methylene blue for 24 hours. In order to assess the degree of microleakage longitudinal cuts were produced by means of a microtome at 0.5 mm and at 1 mm from the restoration margin, and photographs were taken with a stereomicroscope at 100X. Microleakage was classified according to the number of surfaces and the depth at which dye penetration was observed. Data were analysed with ANOVA and post-hoc analysis was performed with Bonferonni test (p<0.05). Statistical analysis exhibited no significant statistical difference between Group 2 and Group 3 (p>0.05). Statistical difference was exhibited between Group 3 and Group 4 (p<0.01), with Group 4 exhibiting lower microleakage values. Group 1 exhibited the lowest mean microleakage values and statistical difference in comparison with all groups (p<0.001). Group 4 exhibited the lowest microleakage values among the cements. Superior marginal integrity is achieved in restored primary teeth when composite resin is used. If the clinical case suggests the use of a glass-ionomer cement, carbomer/fluoroapatite-enhanced glass-ionomer cement is prefered in terms of microleakage.

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

PubMed

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

2017-08-01

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

Maxillary tridimensional changes after slow expansion with leaf expander in a sample of growing patients: a pilot study.

PubMed

Lanteri, V; Gianolio, A; Gualandi, G; Beretta, M

2018-03-01

The aim of this study is to evaluate the dento-alveolar effects of slow maxillary expansion using the Leaf Expander in a sample of growing patients with maxillary transverse deficiency, unilateral cross bite and mandibular shift. The study included 10 patients, 3 male and 7 female (mean age 7.5 + 7 months), treated with Leaf Expander anchored on the upper deciduous teeth. Digital models were obtained by a lab scan of the pvs impressions at the beginning of the therapy (T1) and at the removal of the palatal expander (T2). Five parameters were measured: 1) the distance between the first upper permanent molars; 2) the distance between the upper second deciduous molars; 3) the distance between the upper canine cusps 4) the distance between the first lower permanent molars; 5) the distance of the lower canine cusps. In all patients complete correction of posterior crossbite was achieved on average in 4 months, with a spontaneous expansion of the upper first permanent molars. Significant increases in the dento-alveolar transversal diameters were obtained. Increases were also observed in the anterior mandibular arch diameter (+ 1 mm). These findings suggest that slow maxillary expansion using Leaf Expander appliance could be a reasonable alternative to conventional maxillary expansion therapy in the early mixed dentition.

Clinical Assessment of a New Caries Activity Test Using Dental Plaque Acidogenicity in Children under Three Years of Age.

PubMed

Lee, Hyo-Seol; Lee, Eun-Song; Kang, Si-Mook; Lee, Jae-Ho; Choi, Hyung-Jun; Kim, Baek-Il

The aim of this study was to assess the validity of a new caries activity test that uses dental plaque acidogenicity in children with deciduous dentition. Ninety-two children under the age of three years old underwent clinical examination using the dft index and examinations with two caries activity tests. Plaque samples for the new Cariview(®) test and the saliva sample for the conventional Dentocult SM(®) test were collected, incubated, and scored according to each manufacturers' instruction. The data were analysed using ANOVA and Spearman correlation analyses to evaluate the relationships between the test results and the caries experience. The mean dft index of all of the subjects was 4.73, and 17.4% of the subjects were caries-free. The levels of caries risk based on the new Cariview test score significantly increased with the caries experience (p < 0.01). The test results revealed a stronger correlation with caries indices (dft and dt index) than the conventional SM colony counting method (r = 0.43, r = 0.39, p < 0.01). The new caries activity test to analyse the acidogenic potential of whole microorganisms from dental plaques can be used to evaluate caries risk in children with deciduous teeth.

[Updates on rickets and osteomalacia. dental diseases in rickets].

PubMed

Kubota, Takuo

2013-10-01

Rickets is characterized by mineralization defect in bone and cartilage. X-linked hypophosphatemic rickets (XLH) is the most common form of inherited rickets. Mineralization defect is observed in dentin as well as in bone and cartilage in XLH. The dominant feature is the occurrence of infectious periradicular abscesses on deciduous and permanent teeth, not associated with trauma or decay. Dental care including the maintenance of good oral hygiene and periodical examinations should be performed. A preventive sealing of occlusal surfaces can be considered. Endodontic treatment or extraction are carried out in the presence of periradicular abscesses. Further studies are necessary for elucidating mechanisms of dentin mineralization defect and the occurrence of periradicular abscesses and for developing preventive and curative measures in XLH.

Assessment of Microleakage of a Composite Resin Restoration in Primary Teeth Following Class III Cavity Preparation Using Er, Cr: YSGG laser: An In Vitro Study

PubMed Central

Subramaniam, Priya; Pandey, Annu

2016-01-01

Introduction: Marginal seal integrity is important for a successful adhesive dental restoration. Alterations caused by laser irradiation in the enamel and dentin surface can affect the marginal integrity of adhesive restorations. The aim of this study was to evaluate the microleakage of a composite resin restoration in primary teeth following laser irradiation of enamel and dentin. Methods: Forty freshly extracted sound human primary maxillary and mandibular anterior teeth were used in this study. The teeth were randomly divided into two groups (I and II), with 20 teeth in each. In group I, proximal cavities (Class III) were prepared using an airotor hand –piece and diamond bur. The cavities were etched for 15 seconds with 35% phosphoric acid gel, rinsed with water for 15 seconds, air dried and a bonding agent was applied onto the cavity surfaces and light cured for 20 seconds. The cavities were restored with composite resin and light cured for 40 seconds. In group II, proximal (Class III) cavities were prepared using Erbium, Chromium: Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) (Er,Cr:YSGG) (Biolaseiplus, wave length 2.78 μm). The cavity was then rinsed, air dried and without etching, a bonding agent was applied and light cured for 20 seconds. The cavities were restored in the same manner as that of group I. The treated teeth were mounted on acrylic resin blocks and were subjected to a thermocycling regimen. Following, the teeth were immersed in 2% methylene blue for 24 hours. The teeth were sectioned longitudinally in a bucco-lingual direction using a diamond disc at slow speed. The sections of all the groups were examined under a stereomicroscope for micro-leakage. Results: The mean scores for microleakage in group I was 1.95 ± 1.31 and in group II it was 1.4 ± 1.27. There was no significant difference between the two groups (P = 0.882). Conclusion: No significant difference in microleakage was noticed between the composite resin bonded to lased enamel and dentin and the teeth preparedwith conventional method. PMID:28144438

Ambras Syndrome: First Reported Case in Bangladesh and its Oral Rehabilitation.

PubMed

Khan, M H; Ashrafuzzaman, S M; Taib, A N; Alam, M T; Khan, S H; Goldstein, S K; Rahman, R

2015-10-01

People with rare hypertrichosis syndromes became crowd-drawing money-making phenomena in many 19th century sideshow acts. These individuals have been referred to as dog-men, hair-men, and werewolves. In 1993, Baumister et al. described congenital hypertrichosis lanuginose or Ambras syndrome: a distinct form of congenital hypertrichosis characterized by excessive hair growth over the body and face associated with facial and occasional dental anomalies. Much is not known about this syndrome since fewer than 50 cases have been documented worldwide. In this case report, a nine year old girl presented with excessive hair growth throughout her body that was denser along her midline. Furthermore, her face displayed the typical dysmorphic features characteristic of Ambras syndrome: a round tip nose, thickened nasal cartilage, antiverted nares, prominent philtrum with deep groove, and a trapezoid mouth. Oral examination revealed normal oral mucosa with completely missing and unerupted decidious and permanent teeth. Panoramic radiographs confirmed unerupted deciduous teeth. Previous case reports have mentioned the presence of occasional dental anomalies such as retarded first and second dentition and absence of some teeth. However, this is the first reported case of Ambras syndrome presenting with complete anodontia. Prior cytogenetic studies performed on persons with Ambras syndrome have implicated a balanced pericentric inversion of chromosome 8. However, it is likely that dental anomalies are likely a result of a different genetic rearrangement. Further studies are needed to explore the cause of this rare phenotype of Ambras syndrome with complete unerupted dentition.

Measurement of total occlusal convergence of 3 different tooth preparations in 4 different planes by dental students.

PubMed

Yoon, Stephan S; Cheong, Chan; Preisser, John; Jun, Sangho; Chang, Brian M; Wright, Robert F

2014-08-01

Total occlusal convergence of crown preparation is an important didactic and clinical concept in dental education. The purpose of this study was to compare the discrepancy between the total occlusal convergence of dental students' typodont crown preparations and the ideal range (4 to 10 degrees) in 3 different regions of the mouth and in 4 different planes of the teeth. The dental students of the Class of 2012 at Harvard School of Dental Medicine were asked to prepare typodont teeth for crowns on 3 different teeth, the maxillary left central incisor (ceramic), mandibular left first molar (complete metal), and mandibular left first premolar (metal ceramic), during their third year preclinical summative examination and the Comprehensive Clinical Examination in their fourth year. Eighteen students prepared 3 teeth in their third and fourth years, whereas 19 students participated only in their fourth year, for a total of 55 sets of 3 teeth. By using custom fit die bases to reproduce the position, a novel procedure of measuring each tooth was accomplished in 4 different planes: the faciolingual, mesiodistal, mesiofacial-distolingual, and mesiolingual-distofacial. The total occlusal convergence of each image was measured with a computer screen protractor. The gingival 2 mm of the axial wall was used to determine the taper of each wall. Linear mixed model analysis was used to estimate and compare the total occlusal convergences of different teeth and planes (α=.05). Bonferroni corrections were used to adjust for post hoc multiple comparisons. The mean total occlusal convergence varied by tooth and plane (2-way interaction; P<.001). For the first molar, dental students excessively tapered in all 4 planes; the model-predicted 99% CIs for the total occlusal convergence were as follows: faciolingual (12.7, 19.4), mesiodistal (14.0, 19.3), mesiofacial-distolingual (13,4, 19.4), and mesiolingual-distofacial (13.7, 19.1). For the central incisor, 99% CIs for the total occlusal convergence were (15.9, 24.4) for the faciolingual measurement, providing strong evidence of excessive tapering, and (4.1, 8.0) for the mesiodistal measurement, which was within the ideal total occlusal convergence range. The mesiofacial-distolingual and mesiolingual-distofacial planes in the central incisor and all 4 planes in the first premolar had mean total occlusal convergences that exceeded 10 degrees; however, excessive tapering could not be statistically established, because their CIs included values within the ideal range. The present study found significant evidence of excessive tapering in a study comparing the total occlusal convergence values of crown preparations with those of the ideal preparation for 3 different teeth in 4 different planes. The total occlusal convergence for the molar preparations had the highest mean values. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Prevalence of dental caries and fluoride concentration of drinking water: A systematic review

PubMed Central

Goodarzi, Fatemeh; Mahvi, Amir Hossein; Hosseini, Mostafa; Nodehi, Ramin Nabizadeh; Kharazifard, Mohammad Javad; Parvizishad, Mina

2017-01-01

Background: The objective of this study was to systematically review prevalence of dental caries at different water fluoride levels and emphasize fluoride concentration of drinking water and prevalence of dental caries. Materials and Methods: A comprehensive study was conducted using PubMed database. Inclusion criteria were predefined and some articles fulfilled these criteria. Study validity was assessed by some checklists. Surveys were conducted to determine prevalence of dental caries among individuals. Results: The heterogeneity in the group of children with deciduous teeth in terms of the amount of fluoride in drinking water and social class was significant, and the results of the studies in all the subgroups could not be pooled. However, the heterogeneity of group 2 for subjects with permanent teeth in terms of the fluoride level in drinking water and social class was not significant, and the results of the studies in each subgroup could be pooled together. Conclusion: The meta-regression showed that tooth type and social class had a significant association with the difference in the prevalence of dental caries. Therefore, these variables were the sources of heterogeneity, and the studies must be grouped and subgrouped based on these variables. PMID:28702056

New early Pleistocene hominin teeth from the Swartkrans Formation, South Africa.

PubMed

Pickering, Travis Rayne; Heaton, Jason L; Sutton, Morris B; Clarke, Ron J; Kuman, Kathleen; Senjem, Jess Hutton; Brain, C K

2016-11-01

We describe 14 hominin teeth and tooth fragments excavated recently from Swartkrans Cave (South Africa). The fossils derive from Members 1 (Lower Bank) and 3, from the Member 2/3 interface and from two deposits not yet assigned to member (the "Talus Cone Deposit" and the "Underground North Excavation" [UNE]) of the Swartkrans Formation, and include the first hominin fossil from the UNE, the two smallest Paranthropus robustus deciduous maxillary second molars in the entire hominin fossil record, and one of the smallest P. robustus permanent maxillary second molars from Swartkrans. The small permanent molar is accompanied by another tooth from a different individual but from the same stratigraphic level of the Swartkrans Formation; this second tooth is among, if not, the largest P. robustus permanent maxillary first molars known from anywhere-lending credence to assertions that degrees of body size sexual dimorphism previously ascribed to this species may be underestimated. It is more equivocal whether this evidence also supports hypotheses proposing that P. robustus assemblages from Swartkrans (as well as those from other South African cave sites) formed through the taphonomically biasing actions of large carnivores. Copyright © 2016 Elsevier Ltd. All rights reserved.

Tooth dentin defects reflect genetic disorders affecting bone mineralization

PubMed Central

Vital, S. Opsahl; Gaucher, C.; Bardet, C.; Rowe, P.S.; George, A.; Linglart, A.; Chaussain, C.

2012-01-01

Several genetic disorders affecting bone mineralization may manifest during dentin mineralization. Dentin and bone are similar in several aspects, especially pertaining to the composition of the extracellular matrix (ECM) which is secreted by well-differentiated odontoblasts and osteoblasts, respectively. However, unlike bone, dentin is not remodelled and is not involved in the regulation of calcium and phosphate metabolism. In contrast to bone, teeth are accessible tissues with the shedding of deciduous teeth and the extractions of premolars and third molars for orthodontic treatment. The feasibility of obtaining dentin makes this a good model to study biomineralization in physiological and pathological conditions. In this review, we focus on two genetic diseases that disrupt both bone and dentin mineralization. Hypophosphatemic rickets is related to abnormal secretory proteins involved in the ECM organization of both bone and dentin, as well as in the calcium and phosphate metabolism. Osteogenesis imperfecta affects proteins involved in the local organization of the ECM. In addition, dentin examination permits evaluation of the effects of the systemic treatment prescribed to hypophosphatemic patients during growth. In conclusion, dentin constitutes a valuable tool for better understanding of the pathological processes affecting biomineralization. PMID:22296718

Influence of Endodontic Treatment and Retreatment on the Fatigue Failure Load, Numbers of Cycles for Failure, and Survival Rates of Human Canine Teeth.

PubMed

Missau, Taiane; De Carlo Bello, Mariana; Michelon, Carina; Mastella Lang, Pauline; Kalil Pereira, Gabriel; Baldissara, Paolo; Valandro, Luiz Felipe; Souza Bier, Carlos Alexandre; Pivetta Rippe, Marília

2017-12-01

This study evaluated the effects of endodontic treatment and retreatment on the fatigue failure load, numbers of cycles for failure, and survival rates of canine teeth. Sixty extracted canine teeth, each with a single root canal, were selected and randomly divided into 4 groups (n = 15): untreated, teeth without endodontic intervention; prepared, teeth subjected only to rotary instrumentation; filled, teeth receiving complete endodontic treatment; and retreated, teeth retreated endodontically. After the different endodontic interventions, the specimens were subjected to fatigue testing by the stepwise method: 200 N (× 5000 load pulses), 300 N, 400 N, 500 N, 600 N, 800 N, and 900 N at a maximum of 30,000 load pulses each or the occurrence of fracture. Data from load to failure and numbers of cycles for fracture were recorded and subjected to Kaplan-Meier and Log Rank tests (P < .05), in addition to Weibull analysis. The fractures of the specimens were classified as repairable or catastrophic. The retreated, filled, and untreated groups presented statistically significantly higher fatigue failure loads and numbers of cycles for failure than did the prepared group. Weibull analysis showed no statistically significant difference among the treatments for characteristic load to failure and characteristic number of cycles for failure, although, for number of cycles, a higher Weibull modulus was observed in filled and retreated conditions. The predominant mode of failure was catastrophic. Teeth subjected to complete endodontic treatment and retreatment behaved similarly in terms of fatigue failure load and number of cycles to failure when compared with untreated teeth. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Comparison of dentinal damage induced by different nickel-titanium rotary instruments during canal preparation: An in vitro study.

PubMed

Garg, Shiwani; Mahajan, Pardeep; Thaman, Deepa; Monga, Prashant

2015-01-01

To compare dentinal damage caused by hand and rotary nickel-titanium instruments using ProTaper, K3 Endo, and Easy RaCe systems after root canal preparation. One hundred and fifty freshly extracted mandibular premolars were randomly divided into five experimental groups of 30 teeth each and biomechanical preparation was done: Group 1 with unprepared teeth; Group 2 were prepared with hand files; Group 3 with ProTaper rotary instruments; Group 4 with K3 rotary; Group 5 with Easy RaCe rotary instruments. Then, roots were cut horizontally at 3, 6, and 9 mm from apex and were viewed under stereomicroscope. The presence of dentinal defects was noted. Groups were analyzed with the Chi-square test. Significant difference was seen between groups. No defects were found in unprepared roots and those prepared with hand files. ProTaper, K3 rotary, and Easy RaCe preparations resulted in dentinal defects in 23.3%, 10%, and 16.7% of teeth, respectively. More defects were shown in coronal and middle sections, and no defect was seen in apical third. The present study revealed that use of rotary instruments could result in an increased chance for dentinal defects as compared to hand instrumentation.

Cyclic testing of porcelain laminiate veneers on superficial enamel and dentin: Pressed vs. conventional layered porcelain

NASA Astrophysics Data System (ADS)

Tawde, Shweta

Statement of Problem: Clinicians are inclined towards more aggressive teeth preparations to accommodate the thickness of the veneering material. The principle of conservative tooth preparation is compromised. Purpose: By using a conservative approach to treatment with porcelain veneers, long-lasting, esthetic and functional results may be achieved. Sacrificing as little tooth structure as possible and conserving the supporting tissues will facilitate prospective patients. Materials and Methods: Forty extracted human maxillary and mandibular canines were selected. The teeth were divided into one of two groups (pressable and stackable) and further subdivided according to tooth substrate (all-enamel or mixed enamel-dentin exposure). Twenty canine teeth were allotted to the pressable veneer group and 20 were allotted to the stackable veneer group. Of the 20 teeth in the pressable group, all were pressed with a lithium disilicate ceramic system (IPS e.max Press), 10 with labial tooth reduction of 0.3-0.5 mm maintaining superficial enamel (PEN) and the remaining 10 teeth with labial veneer reduction of 0.8-1.0 mm exposing superficial dentin (PDN). Of the 20 teeth in the stackable group, all were stacked/ layered with conventional feldspathic porcelain (Fortune; Williams/ Ivoclar); with labial veneer reduction of 0.3-0.5 mm maintaining superficial enamel (SEN) and the remaining 10 teeth with labial veneer reduction of 0.8-1.0 mm exposing superficial dentin (SDN). Silicon putty matrix was fabricated prior to teeth preparation to estimate the teeth reduction. The prepared facial reduction was limited to the incisal edge. No incisal or palatal/lingual reduction was performed. Impressions of the prepared teeth were taken in medium/light-bodied PVS. Master casts were made in Resin Rock. The stackable group specimens were made with fabricating refractory dies and after following the recommended steps of laboratory procedure, stackable veneers were processed. The pressable group specimens were fabricated with making a wax-up of the required dimensions and pressing them in the Programmat 5000 system after sprueing and investing them. After all the 40 veneers were checked for internal fit and margins/edges, they were cemented with Variolink Veneer luting cement. Prior to that, the veneers and teeth were prepared for cementation with IPS Ceramic Etching gel and Monobond S and teeth were prepared with Total Etch and ExciTE bond. A thin coat of Rubber separating medium was applied on the root surface of the teeth to simulate the periodontal ligament. Teeth were mounted in Resin rock at 45°. Cyclic loading on an Instron 5848 testing machine was performed. Compressive loading was applied in a cyclical manner using a ramp waveform at a rate of 50N/s. Failure was defined as a crack in the veneer, a crack in the tooth of the veneer, delamination or fracture lines on the veneer/tooth surface. For the first 1000 cycles, the maximum amplitude of the loading was 50N.If the construct survived, another 1000 cycles of loading were applied, using maximum amplitude of 100N. Energy to Failure evaluation was conducted to evaluate the amount of energy the construct absorbed before it failed. All specimens were classified as to whether they survived 2000 cycles of loading, failed during the 100N cyclic loading, or failed during the 50 N cyclic loading. Results: A total of 33 specimens were included in the study. 7 specimens showed catastrophic failure in the initial phases of setting-up the testing parameters on the Instron machine. Mean survivability was higher for the stackable material than the pressed material, and for the veneers attached to enamel than to dentin. When only the material was considered, there was a statistically significant difference between the two groups (p=0.032) in terms of overall survivability with more of the stackable veneers surviving the testing. When the element of veneer thickness is added to the data analysis, failure mode analysis demonstrated a significant difference between the veneer material groups for the veneers in superficial enamel subset (p=0.035) but not the veneers in exposed dentin subset (p=0.225). Thus, for the veneers fabricated on superficial enamel the stackable material construct failed significantly less than the pressable material. Conclusions: Veneers that were stacked on superficial enamel showed high energy to failure compared to the veneers stacked on exposed dentin. Veneers pressed on superficial enamel were stronger than veneers pressed on exposed dentin. Veneers that stacked on superficial and exposed dentin survived cyclic loading longer than the veneers pressed on superficial enamel and exposed dentin. Four Pressed veneers were found to be broken after the 1000 cycles of 100N were complete.

What is the changing frequency of diamond burs?

PubMed

Emir, Faruk; Ayyildiz, Simel; Sahin, Cem

2018-04-01

The purpose of this study was to determine the changing frequency of a diamond bur after multiple usages on 3 different surfaces. Human premolar teeth (N = 26), disc shaped direct metal laser sintered CoCr (N = 3) and zirconia specimens (N = 3) were used in this study. Groups named basically as Group T for teeth, Group M for CoCr, and Group Z for zirconia. Round tapered black-band diamond bur was used. The specimens were randomly divided into three groups and placed with a special assembly onto the surveyor. 1, 5, and 10 preparation protocols were performed to the first, second, and third sub-groups, respectively. The subgroups were named according to preparation numbers (1, 5, 10). The mentioned bur of each group was then used at another horizontal preparation on a new tooth sample. The same procedure was used for CoCr and zirconia disc specimens. All of the bur surfaces were evaluated using roughness analysis. Then, horizontal tooth preparation surfaces were examined under both stereomicroscope and SEM. The depth maps of tooth surfaces were also obtained from digital stereomicroscopic images. The results were statistically analyzed using One-Way ANOVA, and the Tukey HSD post-hoc tests (α=.05). All of the groups were significantly different from the control group ( P <.001). There was no significant difference between groups Z5 and Z10 ( P =.928). Significant differences were found among groups T5, M5, and Z5 ( P <.001). Diamond burs wear after multiple use and they should be changed after 5 teeth preparations at most. A diamond bur should not be used for teeth preparation after try-in procedures of metal or zirconia substructures.

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

PubMed

Attam, K; Talwar, S

2010-09-01

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

Reestablishment of occlusion through overlay removable partial dentures: a case report.

PubMed

Bataglion, César; Hotta, Takami Hirono; Matsumoto, Wilson; Ruellas, Carlos Ventura de Oliveira

2012-01-01

Loss of posterior teeth may cause an imbalance in the stomatognathic system. Overlay removable partial dentures (ORPD) are a reversible and relatively inexpensive treatment for patients with severely worn teeth. This paper presents a treatment with ORPD in a 55-year-old male patient who had severe attrition in the maxillary and mandibular teeth, temporomandibular joint pain and reduced vertical dimension of occlusion (VDO). The treatment consisted in the reestablishment of the VDO using Lucia's jig, fabricating removable partial denture with reconstruction of the worn teeth without preparation. This therapy can be used as an alternative treatment to provide esthetic, function and stable occlusion in patients with severely worn teeth.

The Effect of Four Commonly Used Root Conditioner Agents in Different Time Periods Applied on Periodontally Diseased and Healthy Teeth

PubMed Central

P, Torkzaban; S, Seyedzadeh Sabounchi

2016-01-01

Statement of Problem: Root surface contamination or infection can potentially change the consequences of regenerative periodontal therapies and therefore the modification and disinfection of the contaminated root surfaces are necessary. Objectives: This study aimed to compare the surface characteristics of the extracted human teeth after exposure to four root conditioners in different time periods. Materials and Methods: The study samples were prepared from 40 freshly extracted teeth including 20 affected teeth with periodontal diseases and 20 healthy teeth. After performing root planning, 240 dentinal block samples were prepared and each affected and healthy sample was randomly allocated to receive one of the following root conditioners; Ethylenediaminetetraaceti acid (EDTA), citric acid, doxycycline, and tetracycline or rinsed with normal saline as the control agent. The prepared specimens were evaluated using scanning electron microscope and the inter-group differences and changes in study indices; dentin (%), tubular spaces (%), and diameter of dentinal tubules (μm²) were compared using one-way ANOVA test. Results: In the control group receiving normal saline, the changes in the indicators of dentin, tubular spaces, and diameter of dentinal tubules remained insignificant in all time periods. EDTA, citric acid, and tetracycline had chelating effects on the study indices; however, doxycycline led to gradual decrease of the tubular space and diameter as well as increase in dentin percentage. Conclusions: In different time intervals and when considering healthy or affected tooth surfaces, the effect of conditioning agents could be different. Amongst the four agents used, EDTA and tetracycline consistently increased the diameter of tubules and percentage of patent tubules in both healthy and diseased teeth. PMID:28959749

[Prosthetic rehabilitation of patients with parodontitis based upon the use of 3D-technologies--clinical case example].

PubMed

Riakhovskiĭ, A N

2011-01-01

Clinical case of prosthetic rehabilitation of patient (female) with generalized parodontitis complicated by defects and deformations of dentitions was offered. Using 3D-technologies position of teeth was corrected with the help of a series of temporary transparent splints-modifiers with subsequent guy splintage and esthetic 3D-planning of front teeth forms. Teeth forms correction was made by composite using preliminary prepared templet.

Potential of nano-silver fluoride for tooth enamel caries prevention

NASA Astrophysics Data System (ADS)

Silva, Amitis V. C.; Mota, Cláudia C. B. O.; Teixeira, Joás. A.; Lins, Emery C.; Gomes, Anderson S. L.; Rosenblatt, Aronita

2018-02-01

This ex vivo study evaluated the efficiency of nano-silver fluoride (NSF) to enamel remineralization of deciduous teeth submitted to a high cariogenic challenge. 33 specimens of sound enamel were distributed into three groups: treated with sodium fluoride, with NSF, and deionized water. All specimens were submitted to microhardness test before chemical caries induction; post-induction of caries; and post-cariogenic challenge. The high cariogenic challenge was carried out in 14 daily cycles. There was no significant statistical difference (p=0.958) of enamel microhardness between NSFtreated and NaF-treated specimens. However, it presented significant difference between water-treated specimens and both NSF-treated and NaF-treated specimens (p=0.003).Furthermore, optical coherence tomography was employed for caries diagnosis, as it can be used in clinical environment.

The evolution of menstruation: A new model for genetic assimilation

PubMed Central

Emera, D.; Romero, R.; Wagner, G.

2012-01-01

Why do humans menstruate while most mammals do not? Here, we present our answer to this long-debated question, arguing that (i) menstruation occurs as a mechanistic consequence of hormone-induced differentiation of the endometrium (referred to as spontaneous decidualization, or SD); (ii) SD evolved because of maternal-fetal conflict; and (iii) SD evolved by genetic assimilation of the decidualization reaction, which is induced by the fetus in non-menstruating species. The idea that menstruation occurs as a consequence of SD has been proposed in the past, but here we present a novel hypothesis on how SD evolved. We argue that decidualization became genetically stabilized in menstruating lineages, allowing females to prepare for pregnancy without any signal from the fetus. We present three models for the evolution of SD by genetic assimilation, based on recent advances in our understanding of the mechanisms of endometrial differentiation and implantation. Testing these models will ultimately shed light on the evolutionary significance of menstruation, as well as on the etiology of human reproductive disorders like endometriosis and recurrent pregnancy loss. PMID:22057551

A scanning electron microscopic study to evaluate the efficacy of NaviTip FX in removing the canal debris during root canal preparation: an in vitro study.

PubMed

Chandra, Vinay; Gandi, Padma; Shivanna, Anil Kumar; Srinivas, Siva; Himgiri, S; Nischith, K G

2013-07-01

To evaluate the efficacy of NaviTip FX in removing the canal debris during root canal preparation using scanning electron microscopic study. Thirty single rooted teeth with completely formed apices were used in this study. Standard endodontic access cavity preparations were performed. Then the teeth were randomly divided into two groups: groups 1 and 2 of 15 teeth each group. For group 1, NaviTip FX (brush covered needle) was used to irrigate the canal with 5.25% sodium hypochlorite after each instrument use. For group 2, NaviTip (brushless needle) was used for irrigation following each instrument use. ProTaper rotary files were used for the canal preparation. The teeth were then cleaned and dried before splitting them into two halves. The half with most visible part of the apex was used for scanning electron microscopic evaluation. The results were statistically analyzed using the Mann-Whitney U-test at significance level p < 0.005. The mean values for coronal and middle third of group 1 showed lower debris scores than group 2 and this difference was statistically significant at a p-value 0.01 and 0.05 respectively, but no significance difference between them at the apical third at a p-value of < 0.05. The NaviTip FX (brush covered needle) showed effectively better canal wall debris removal than the NaviTip (brushless needle).

Assessment of apical transportation caused by nickel-titanium rotary systems with full rotation and reciprocating movements using extracted teeth and resin blocks with simulated root canals: A comparative study.

PubMed

Alrahabi, M; Zafar, M S

2018-06-01

: We compared apical transportation in the WaveOne and ProTaper Next systems, which are rotary nickel-titanium systems with reciprocating and continuous rotation movements, respectively, using manual measurements obtained from resin blocks with simulated root canals and double digital radiographs of extracted teeth. : We used 30 resin blocks with simulated root canals and 30 extracted teeth for this study. The same endodontist performed root canal shaping using the WaveOne or ProTaper Next system. We assessed apical transportation by measuring the amounts (in mm) of material lost 1 mm from the apical foramen in the resin blocks and by using double digital radiography for the extracted teeth. Significant differences between groups were assessed using t-tests. P < 0.05 was considered statistically significant. : The amount of apical transportation differed significantly between the two systems when resin blocks were used for assessment (P < 0.05), but there were no significant differences when extracted teeth were used (P < 0.05). In the current study, there was no significant difference in apical transportation between natural teeth prepared using WaveOne and those prepared using ProTaper Next. However, significant differences were observed between the two systems with resin blocks. These findings indicate that the use of resin blocks is not an accurate method for apical transportation evaluation.

The reinforcement effect of polyethylene fibre and composite impregnated glass fibre on fracture resistance of endodontically treated teeth: An in vitro study

PubMed Central

Luthria, Archana; Srirekha, A; Hegde, Jayshree; Karale, Rupali; Tyagi, Sanjana; Bhaskaran, Sajeev

2012-01-01

Aim: The aim of this study was to evaluate the fracture resistance of endodontically treated maxillary premolars with wide mesio-occluso-distal (MOD) cavities restored with either composite resin, or composite resin reinforced with different types of fibres. Materials and Methods: Fifty human maxillary premolars were selected. Five intact teeth served as positive controls. Endodontic therapy was carried out in the remaining forty-five teeth. Standardized MOD cavities were prepared in all the teeth. The teeth were restored with a nanocomposite using an incremental technique. These forty five teeth were randomly divided into three experimental groups (Group A, B and C) (n = 15). The teeth in Group A did not undergo any further procedures. The teeth in Group B and C were reinforced with composite impregnated glass fibre and polyethylene fibre, respectively. Fracture resistance was measured in Newtons (N). Results: The positive controls showed the highest mean fracture resistance (811.90 N), followed by Group B (600.49N), Group A (516.96N) and Group C (514.64N), respectively. One Way analysis of variance (ANOVA) test revealed a statistically significant difference between all the groups (P = 0.001). Post-hoc Tukey test revealed a moderately significant difference (P = 0.034) between Control and Group B, and a strongly significant difference between Control and Group A (P = 0.002), and Control and Group C (P = 0.001). Conclusions: Endodontic therapy and MOD cavity preparation significantly reduced the fracture resistance of endodontically treated maxillary premolars (P = 0.001). No statistically significant difference was found between the experimental groups (Group A, B and C) (P > 0.1). However, the fracture resistance of the composite impregnated glass fibre reinforced group was much higher than the others. PMID:23112487

Fracture resistance of simulated immature teeth filled with Biodentine and white mineral trioxide aggregate - an in vitro study.

PubMed

Elnaghy, Amr M; Elsaka, Shaymaa E

2016-04-01

The purpose of this study was to evaluate the long-term fracture resistance of simulated immature teeth filled with Biodentine (BD) and white mineral trioxide aggregate (WMTA) as pulp space barriers for regenerative endodontic procedures (REPs). Sixty extracted human maxillary anterior teeth were divided into four groups of 15 teeth each. Positive control teeth received no treatment. The remaining teeth were prepared until a size 6 Peeso (1.7 mm) could be passed 1 mm beyond the apex. Then, an engineering twist drill of 3 mm diameter was used to extend the preparation of the canal 3 mm below CEJ. The root canals were irrigated and disinfected according to AAE considerations for REPs. The canals were filled with either BD or WMTA. The negative control canals were left unfilled. The coronal access cavities were restored with glass ionomer followed by composite resin. The teeth were placed in phosphate-buffered saline solution and stored for 12 months. Each specimen was then subjected to fracture testing using a universal testing machine. The peak load to fracture and the fracture resistance were recorded, and the data were analysed statistically. The positive control group had the highest fracture resistance and differed significantly (P < 0.05) from the other experimental groups. No significant difference was found between BD and WMTA (P > 0.05). Considering the risk of cervical root fracture for pulpless infected immature teeth treated with REPs, after 12 months, there was no difference between WMTA and BD regarding the resistance to root fracture. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparison Of Pre-Operative Curvature With Postoperative Curvature In Root Canals Treated With K-3 Rotary Systems.

PubMed

Nagi, Sana Ehsen; Khan, Farhan Raza

2017-01-01

With root canal treatment, the organic debris and micro-organisms from pulp space is removed and an ideal canal preparation is achieved that is conducive of hermetic obturation. The purpose of this study was to correlate the pre-operative canal curvature with the postoperative curvature in human extracted teeth prepared with K-3 rotary systems. The root canal preparation was carried out on extracted human molars and premolars using K-3 endodontic rotary files. A pre and post-operative image of the teeth using digital radiograph were taken in order to compare pre and post-operative canal curvature. The images were saved in an images retrieval system (Gendex software, USA). Change in the canal curvature was measured using the software measuring tool (Vixwin software, USA). Student paired t-test and Pearson correlation test was applied at 0.05 level of significance. There is a statistically significant difference between pre-operative and post-operative canal curvature (p-value <0.001) and a strong positive correlation (91% correlation) between pre-operative and post-operative canal curvature in teeth prepared with the K-3 rotary files. A significant difference between pre and post instrumentation curvature was found. Degree of canal curvature was not correlated with time taken for canal preparation.

Morphological description and comparison of the dental remains from Atapuerca-Sima de los Huesos site (Spain).

PubMed

Martinón-Torres, María; Bermúdez de Castro, José María; Gómez-Robles, Aida; Prado-Simón, Leyre; Arsuaga, Juan Luis

2012-01-01

The systematic excavation of the Sima de los Huesos (SH) site in Sierra de Atapuerca (Burgos, Spain) has yielded the largest hominin collection worldwide for the Middle Pleistocene. The dental sample now consists of more than 500 teeth that provide exceptional opportunities to define the dental morphological pattern of a Middle Pleistocene population as well as develop hypotheses about the origins of the Neanderthals. The dental collection has now increased to over 533 specimens (525 permanent and 8 deciduous teeth), necessitating new morphological assessments. Thus, we present a detailed morphological description of the SH permanent dentition recovered up to 2007, accomplishing comparisons with European Middle Pleistocene hominins, Neanderthals, and early and contemporary Homo sapiens. We find that SH dentitions present all the morphological traits that, either in their degree of expression, frequency, or particular combination, are usually considered as typical of Homo neanderthalensis. This study ratifies the deep roots of the Neanderthal lineage in the Middle Pleistocene of Europe. In addition, SH teeth are morphologically "more Neanderthal" than other penecontemporaneous Middle Pleistocene samples such as Mauer or Arago, and even more derived than some classic Neanderthal samples. Thus, our study would not sustain the linearity of the accretion process hypothesized for the origins of the Neanderthals, and we suggest that other evolutionary models and scenarios should be explored for the Middle and Upper Pleistocene of Europe. We propose that more than one hominin lineage may have coexisted during the Middle Pleistocene in Europe. Copyright © 2011 Elsevier Ltd. All rights reserved.

Prevalence of dental anomalies in deciduous dentition and its association with succedaneous dentition: A cross-sectional study of 4180 South Indian children.

PubMed

Shilpa, G; Gokhale, Niraj; Mallineni, Sreekanth Kumar; Nuvvula, Sivakumar

2017-01-01

The objective of this study was to estimate the prevalence of dental anomalies in primary dentition of Indian population. This cross-sectional study was conducted on 4180 children in the age of 2-6 years. Anomalies were classified based on Kreiborg criteria. The term "double tooth" was used to avoid misinterpretation between gemination. and fusion. Patients having radiographs were also examined for associated dental anomalies in permanent dentition. The occurrence and gender prevalence were evaluated using descriptive statistics. About 95. (2.27%) children exhibited at least one dental anomaly. Thirty.seven children showed 51 missing teeth. (0.88%), mostly in lower right incisors with a statistically significant difference between arches. (P = 0.0056) Nine children. (0.21%) had supernumerary teeth commonly in the right maxilla. Two cases of oligodontia. (0.04%) and talon cusps. (0.04%) and one case of triple tooth. (0.02%) were observed. Forty children. (0.95%) had 43 double teeth mostly in the right mandible with a statistically significant difference between the arches. (P = 0.0105). No significant difference was observed based on gender and arch, but they were statistically significant between the right and left sides. (P = 0.018). Among the children with radiographs available, 45% showed anomalies in the succedaneous dentition. The prevalence rates of children with double tooth, hypodontia, and hyperdontia in our study are 0.95%, 0.88%, and 0.21%, respectively. The overall prevalence rate of anomalies among boys was higher than girls.

Patterns of morphological variation in enamel–dentin junction and outer enamel surface of human molars

PubMed Central

Morita, Wataru; Yano, Wataru; Nagaoka, Tomohito; Abe, Mikiko; Ohshima, Hayato; Nakatsukasa, Masato

2014-01-01

Tooth crown patterning is governed by the growth and folding of the inner enamel epithelium (IEE) and the following enamel deposition forms outer enamel surface (OES). We hypothesized that overall dental crown shape and covariation structure are determined by processes that configurate shape at the enamel–dentine junction (EDJ), the developmental vestige of IEE. This this hypothesis was tested by comparing patterns of morphological variation between EDJ and OES in human permanent maxillary first molar (UM1) and deciduous second molar (um2). Using geometric morphometric methods, we described morphological variation and covariation between EDJ and OES, and evaluated the strength of two components of phenotypic variability, canalization and morphological integration, in addition to the relevant evolutionary flexibility, i.e. the ability to respond to selective pressure. The strength of covariation between EDJ and OES was greater in um2 than in UM1, and the way that multiple traits covary between EDJ and OES was different between these teeth. The variability analyses showed that EDJ had less shape variation and a higher level of morphological integration than OES, which indicated that canalization and morphological integration acted as developmental constraints. These tendencies were greater in UM1 than in um2. On the other hand, EDJ and OES had a comparable level of evolvability in these teeth. Amelogenesis could play a significant role in tooth shape and covariation structure, and its influence was not constant among teeth, which may be responsible for the differences in the rate and/or period of enamel formation. PMID:24689536

Establishing the diagnostic criteria for eruption disorders based on genetic and clinical data.

PubMed

Rhoads, Stephanie Golubic; Hendricks, Heather M; Frazier-Bowers, Sylvia A

2013-08-01

Proper diagnosis and management of eruption disturbances remains challenging but is critical to a functional occlusion. The objective of this study was to establish definitive criteria to differentiate and diagnose eruption disorders, specifically primary failure of eruption (PFE) and ankylosis. Sixty-four affected persons were placed into 3 cohorts: PFE diagnosed through confirmed PTH1R mutation (n = 11), PFE diagnosed based on clinical criteria (n = 47), and ankylosis diagnosed based on clinical criteria (n = 6). These groups were assessed to identify clinical features that differentiate PFE and ankylosis. Ninety-three percent of the subjects in the genetic and clinical PFE cohorts combined (n = 58) and 100% in the genetic PFE cohort had at least 1 infraoccluded first permanent molar. Additionally, a novel functional PTH1R mutation, 1092delG, was identified and linked to PFE in the deciduous dentition. An infraoccluded, supracrestal first molar is a hallmark of PFE, often involving both arches in the permanent or deciduous dentition, and with unilateral or bilateral affection, infraoccluded second premolar or second molar, and multiple affected adjacent teeth. Our results further suggest that PFE and ankylosis might be clinically indistinguishable without knowledge of prior trauma, treatment history, genetic information, or obliteration of the periodontal ligament space. Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Assessing human weaning practices with calcium isotopes in tooth enamel

PubMed Central

Tacail, Théo; Thivichon-Prince, Béatrice; Martin, Jeremy E.; Charles, Cyril; Viriot, Laurent

2017-01-01

Weaning practices differ among great apes and likely diverged during the course of human evolution, but behavioral inference from the fossil record is hampered by a lack of unambiguous biomarkers. Here, we show that early-life dietary transitions are recorded in human deciduous tooth enamel as marked variations in Ca isotope ratios (δ44/42Ca). Using a sequential microsampling method along the enamel growth axis, we collected more than 150 enamel microsamples from 51 deciduous teeth of 12 different modern human individuals of known dietary histories, as well as nine enamel samples from permanent third molars. We measured and reconstructed the evolution of 44Ca/42Ca ratios in enamel from in utero development to first months of postnatal development. We show that the observed variations of δ44/42Ca record a transition from placental nutrition to an adult-like diet and that Ca isotopes reflect the duration of the breastfeeding period experienced by each infant. Typically, the δ44/42Ca values of individuals briefly or not breastfed show a systematic increase during the first 5–10 mo, whereas individuals with long breastfeeding histories display no measurable variation in δ44/42Ca of enamel formed during this time. The use of Ca isotope analysis in tooth enamel allows microsampling and offers an independent approach to tackle challenging questions related to past population dynamics and evolution of weaning practices in hominins. PMID:28559355

Er:YAG laser: antimicrobial effects in the root canals of dogs' teeth with pulp necrosis and chronic periapical lesions.

PubMed

Leonardo, Mário R; Guillén-Carías, M G; Pécora, J D; Ito, I Y; Silva, L A B

2005-06-01

Our goal in this study was to evaluate the antimicrobial effect of Er:YAG laser applied after biomechanical preparation of the root canals of dog's teeth with apical periodontitis. Various in vitro studies have reported effective bacterial reduction in infected root canals using Er:YAG laser. However, there is no in vivo research to support these results. Forty root canals of dogs' premolar teeth with pulp necrosis and chronic periapical lesions were used. An initial microbiological sample was taken, and after biomechanical preparation was carried out, a second microbiological sample was taken. The teeth were divided into two groups: Group I-biomechanical preparation was taken of root canals without Er:YAG laser application; Group II-biomechanical preparation was taken of root canals with Er:YAG laser application using 140-mJ input, 63-mJ output/15 Hz. After coronal sealing, the root canals were left empty for 7 days at which time a third microbiological sample was taken. The collected material was removed from the root canal with a #40 K file and placed in transport media. It was serially diluted and seeded on culture dishes selective for anaerobes, aerobes, and total streptococci. Colony-forming units per milliliter (CFU/mL) were counted. Groups I and II showed an increase of CFU/mL for all microorganisms 7 days after treatment, being statistically significant for anaerobes in Group I and for anaerobes and total streptococci in Group II. When comparing CFU/mL of Groups I and II, there was a statistically significant increase after 7 d for total streptococci in Group II. Er:YAG laser applied after biomechanical preparation did not reduce microorganisms in the root canal system.

Effects of low-level laser therapy on stem cells from human exfoliated deciduous teeth

PubMed Central

FERNANDES, Ana Paula; JUNQUEIRA, Marina de Azevedo; MARQUES, Nádia Carolina Teixeira; MACHADO, Maria Aparecida Andrade Moreira; SANTOS, Carlos Ferreira; OLIVEIRA, Thais Marchini; SAKAI, Vivien Thiemy

2016-01-01

ABSTRACT Low-Level Laser Therapy stimulates the proliferation of a variety of types of cells. However, very little is known about its effect on stem cells from human exfoliated deciduous teeth (SHED). Objective This study aimed to evaluate the influence of different laser therapy energy densities on SHED viability and proliferation. Material and Methods SHED were irradiated according to the groups: I (1.2 J/cm2 - 0.5 mW – 10 s), II (2.5 J/cm2 – 10 mW – 10 s), III (3.7 J/cm2 – 15 mW – 10 s), IV (5.0 J/cm2 – 20 mW – 10 s), V (6.2 J/cm2 – 25 mW – 10 s), and VI (not irradiated – control group). Cell viability was assessed 6 and 24 h after irradiation measuring the mitochondrial activity and using the Crystal Violet assay. Cell proliferation was assessed after 24, 48, and 72 h of irradiation by SRB assay. Results MTT assay demonstrated differences from 6 to 24 hours after irradiation. After 24 h, groups I and IV showed higher absorbance values than those of control group. Crystal Violet assay showed statistically differences in the absorbance rate from 6 to 24 h after irradiation for groups III and VI. At 24 h after irradiation, Group III absorbance rate was greater than that of groups I, II, and IV. Group VI absorbance rate was greater than that of groups I and IV. SRB assay showed that the group I had higher rates than those of groups II, III, V, and VI, at 24 h after irradiation. After 48 h, group I exhibited the greatest cell proliferation rate followed by groups III, V, and VI. After 72 h, group III exhibited the lowest cell proliferation rate than those of groups II, IV, and V. Conclusions The Low-Level Laser Therapy energy densities used in this study did not cause loss of cell viability and stimulated SHED proliferation within the parameters described in this study. PMID:27556203

Multifaceted Therapeutic Benefits of Factors Derived From Dental Pulp Stem Cells for Mouse Liver Fibrosis.

PubMed

Hirata, Marina; Ishigami, Masatoshi; Matsushita, Yoshihiro; Ito, Takanori; Hattori, Hisashi; Hibi, Hideharu; Goto, Hidemi; Ueda, Minoru; Yamamoto, Akihito

2016-10-01

: Chronic liver injury from various causes often results in liver fibrosis (LF). Although the liver possesses endogenous tissue-repairing activities, these can be overcome by sustained inflammation and excessive fibrotic scar formation. Advanced LF leads to irreversible cirrhosis and subsequent liver failure and/or hepatic cancer. Here, using the mouse carbon tetrachloride (CCl 4 )-induced LF model, we showed that a single intravenous administration of stem cells derived from human exfoliated deciduous teeth (SHEDs) or of SHED-derived serum-free conditioned medium (SHED-CM) resulted in fibrotic scar resolution. SHED-CM suppressed the gene expression of proinflammatory mediators, such as TNF-α, IL-1β, and iNOS, and eliminated activated hepatic stellate cells by inducing their apoptosis, but protected parenchymal hepatocytes from undergoing apoptosis. In addition, SHED-CM induced tissue-repairing macrophages that expressed high levels of the profibrinolytic factor, matrix metalloproteinase 13. Furthermore, SHED-CM suppressed the CCl 4 -induced apoptosis of primary cultured hepatocytes. SHED-CM contained a high level of hepatocyte growth factor (HGF). Notably, HGF-depleted SHED-CM (dHGF-CM) did not suppress the proinflammatory response or resolve fibrotic scarring. Furthermore, SHED-CM, but not dHGF-CM, inhibited CCl 4 -induced hepatocyte apoptosis. These results suggest that HGF plays a central role in the SHED-CM-mediated resolution of LF. Taken together, our findings suggest that SHED-CM provides multifaceted therapeutic benefits for the treatment of LF. This study demonstrated that a single intravenous administration of stem cells from human exfoliated deciduous teeth (SHEDs) or of the serum-free conditioned medium (CM) derived from SHEDs markedly improved mouse liver fibrosis (LF). SHED-CM suppressed chronic inflammation, eliminated activated hepatic stellate cells by inducing their apoptosis, protected hepatocytes from undergoing apoptosis, and induced differentiation of tissue-repairing macrophages expressing high levels of the profibrinolytic factor matrix metalloproteinase 13. Furthermore, hepatocyte growth factor played a central role in the SHED-CM-mediated resolution of LF. This is the first report demonstrating the multifaceted therapeutic benefits of secreted factors derived from SHEDs for LF. ©AlphaMed Press.

Priming Dental Pulp Stem Cells With Fibroblast Growth Factor-2 Increases Angiogenesis of Implanted Tissue-Engineered Constructs Through Hepatocyte Growth Factor and Vascular Endothelial Growth Factor Secretion

PubMed Central

Gorin, Caroline; Rochefort, Gael Y.; Bascetin, Rumeyza; Ying, Hanru; Lesieur, Julie; Sadoine, Jérémy; Beckouche, Nathan; Berndt, Sarah; Novais, Anita; Lesage, Matthieu; Hosten, Benoit; Vercellino, Laetitia; Merlet, Pascal; Le-Denmat, Dominique; Marchiol, Carmen; Letourneur, Didier; Nicoletti, Antonino; Vital, Sibylle Opsahl; Poliard, Anne; Salmon, Benjamin; Germain, Stéphane

2016-01-01

Tissue engineering strategies based on implanting cellularized biomaterials are promising therapeutic approaches for the reconstruction of large tissue defects. A major hurdle for the reliable establishment of such therapeutic approaches is the lack of rapid blood perfusion of the tissue construct to provide oxygen and nutrients. Numerous sources of mesenchymal stem cells (MSCs) displaying angiogenic potential have been characterized in the past years, including the adult dental pulp. Establishment of efficient strategies for improving angiogenesis in tissue constructs is nevertheless still an important challenge. Hypoxia was proposed as a priming treatment owing to its capacity to enhance the angiogenic potential of stem cells through vascular endothelial growth factor (VEGF) release. The present study aimed to characterize additional key factors regulating the angiogenic capacity of such MSCs, namely, dental pulp stem cells derived from deciduous teeth (SHED). We identified fibroblast growth factor-2 (FGF-2) as a potent inducer of the release of VEGF and hepatocyte growth factor (HGF) by SHED. We found that FGF-2 limited hypoxia-induced downregulation of HGF release. Using three-dimensional culture models of angiogenesis, we demonstrated that VEGF and HGF were both responsible for the high angiogenic potential of SHED through direct targeting of endothelial cells. In addition, FGF-2 treatment increased the fraction of Stro-1+/CD146+ progenitor cells. We then applied in vitro FGF-2 priming to SHED before encapsulation in hydrogels and in vivo subcutaneous implantation. Our results showed that FGF-2 priming is more efficient than hypoxia at increasing SHED-induced vascularization compared with nonprimed controls. Altogether, these data demonstrate that FGF-2 priming enhances the angiogenic potential of SHED through the secretion of both HGF and VEGF. Significance The results from the present study show that fibroblast growth factor-2 (FGF-2) priming is more efficient than hypoxia at increasing dental pulp stem cells derived from deciduous teeth (SHED)-induced vascularization compared with nonprimed controls. Together, these data demonstrate that FGF-2 priming enhances the angiogenic potential of SHED through the secretion of both hepatocyte growth factor and vascular endothelial growth factor. PMID:26798059

Teaching of direct posterior resin composite restorations in UK dental therapy training programmes.

PubMed

Lynch, C D; Wilson, N H F

2010-05-08

With the numbers of dental therapists involved in the delivery of dental care within the UK on the increase, and the trend towards the use of direct resin composites (composites) for the restoration of posterior teeth, this study was undertaken to describe the teaching of posterior composites in dental therapy training programmes in the UK. A secondary aim was to identify differences in techniques for posterior composites taught within these dental therapy training programmes. In 2008/9, a questionnaire seeking information on the teaching of posterior composites was distributed by email to 13 centres with dental therapy training programmes in the UK. This questionnaire sought information relating to the teaching of direct posterior composites to dental therapy students, including the amounts of preclinical and clinical teaching in respect of deciduous and permanent teeth, numbers of restorations placed, contraindications to placement, and details in respect of operative techniques. Ten completed responses were received (response rate = 77%). In ten programmes, student dental therapists received clinical training in the placement of composite restorations in the occlusal surfaces of premolar and permanent molar teeth, and nine programmes included such training for two and three surface occlusoproximal restorations. The mean proportions of posterior restorations placed clinically by the trainee dental therapists in permanent teeth using dental amalgam and composite were 52% and 46% respectively (range: amalgam = 20-95%; composite = 5-70%). With the exception of one programme, the teaching of posterior composites is a well established element of dental therapy training. Some variations were noted in the teaching of clinical techniques between respondent training centres. It is suggested that to ensure harmony in approaches to treatments provided by graduated therapists that training centres look to relevant consensus documents, such as those of the British Association for the Teaching of Conservative Dentistry. The findings of our study are important for the future provision of oral healthcare, given the growing evidence base in favour of minimally invasive dentistry.

The failures of root canal preparation with hand ProTaper.

PubMed

Bătăiosu, Marilena; Diaconu, Oana; Moraru, Iren; Dăguci, C; Tuculină, Mihaela; Dăguci, Luminiţa; Gheorghiţă, Lelia

2012-07-01

The failures of root canal preparation are due to some anatomical deviation (canal in "C" or "S") and some technique errors. The technique errors are usually present in canal root cleansing and shaping stage and are the result of endodontic treatment objectives deviation. Our study was made on technique errors while preparing the canal roots with hand ProTaper. Our study was made "in vitro" on 84 extracted teeth (molars, premolars, incisors and canines). The canal root of these teeth were cleansed and shaped with hand ProTaper by crown-down technique and canal irrigation with NaOCl(2,5%). The dental preparation control was made by X-ray. During canal root preparation some failures were observed like: canal root overinstrumentation, zipping and stripping phenomenon, discarded and/or fractured instruments. Hand ProTaper represents a revolutionary progress of endodontic treatment, but a deviation from accepted rules of canal root instrumentation can lead to failures of endodontic treatment.

The teeth of the horse: evolution and anatomo-morphological and radiographic study of their development in the foetus.

PubMed

Soana, S; Gnudi, G; Bertoni, G

1999-12-01

The aim of this work was to study the ontogenetic process in teeth from their early appearance in the ossifying matrix of the mandible and maxilla, in different foetuses of scalar ages. Radiographic examinations of the skull and mandible hemisections were performed and the latero-medial (LM) and dorsoventral (DV) projections for the skull and mandible were analysed. A high-definition film-screen combination was used for this study. The exposure values ranged from 35 kV/6 mAs to 58 kV/10 mAs, according to the size of the skulls and their degree of ossification. The first dental germ observed was the P3, at 138-140 days of pregnancy. At 146 days, P2 and P4 dental germs were visible. At 160-168 days, the dental germ of the first deciduous incisor tooth (I1) appeared; at 180-188 days of pregnancy the germ of the second (I2), and at 224 days the germ of the third (I3), were detectable. At 275 days the dental germ of the mandibular first molar tooth (M1) appeared, while the maxillary M1, which was not visible radiographically, was represented by a jelly-like amorphous body within its alveolar cavity.

Pulp Calcification in Traumatized Primary Teeth - Classification, Clinical And Radiographic Aspects.

PubMed

Mello-Moura, Anna Carolina Volpi; Santos, Ana Maria Antunes; Bonini, Gabriela Azevedo Vasconcelos Cunha; Zardetto, Cristina Giovannetti Del Conte; Moura-Netto, Cacio; Wanderley, Marcia Turolla

The aim of this study was to standardize the nomenclature of pulp alteration to pulp calcification (PC) and to classify it according to type, quantity and location, as well as relate it to clinical and radiographic features. The dental records of 946 patients from the Research and Clinical Center for Dental Trauma in Primary Teeth were studied. Two hundred and fifty PC-traumatized upper deciduous incisors were detected. According to radiographic analysis of the records, 62.5% showed diffuse calcification, 36.3% tube-like calcification, and 1.2% concentric calcification. According to the extension of pulp calcification, the records showed: 80% partial calcification, 17.2% total coronal calcification and partial radicular calcification, and 2.8 % total coronal and radicular calcification. As for location, only 2.4% were on the coronal pulp, 5.2% on the radicular pulp and 92.4% on both radicular and coronal pulp. Regarding coronal discoloration, 54% were yellow and 2% gray. In relation to periradicular changes, 10% showed widened periodontal ligament space, 3.1% internal resorption, 10% external resorption, 10.4% periapical bone rarefaction. Since PC is a general term, it is important to classify it and correlate it to clinical and radiographic changes, in order to establish the correct diagnosis, treatment and prognosis of each case.

Environmental stress in the Early Mediaeval Slavic population at Borovce (Slovakia).

PubMed

Obertová, Zuzana

2005-01-01

Several palaeopathological indicators examined in skeletal samples are caused by stress during childhood and remain visible in adults. In this study, dental enamel hypoplasia was observed in 451 individuals from the Early Mediaeval (8th to beginning of 12th c. AD) Slavic skeletal series at Borovce (Slovakia). The presence of enamel hypoplasia was scored in all types of deciduous and permanent teeth. More than one-fourth (27.2%) of the individuals with preserved permanent teeth showed enamel hypoplasia. No significant differences in the occurrence of the enamel lesions were found between males and females. The age at development of hypoplasias was estimated for 74 individuals by measuring the distance of the defect from the cemento-enamel junction. The hypoplastic defects appeared most frequently between 2.5 and 3.0 years. Following the trends observed in the distribution of age at development of the enamel lesions between subadults and adults, individuals stressed earlier in life had a reduced ability to cope with later insults. High prevalence of enamel hypoplasia, especially among 10-14-year-old growing juveniles, has led to the assumption that the Borovce population lived a considerably long period under conditions of high environmental pathogen load, and probably also suffered from some nutritional deficiencies.

[Posterior ceramic bonded partial restorations].

PubMed

Mainjot, Amélie; Vanheusden, Alain

2006-01-01

Posterior ceramic bonded partial restorations are conservative and esthetic approaches for compromised teeth. Overlays constitute a less invasive alternative for tooth tissues than crown preparations. With inlays and onlays they are also indicated in case of full arch or quadrant rehabilitations including several teeth. This article screens indications and realization of this type of restorations.

The marginal fit of lithium disilicate crowns: Press vs. CAD/CAM.

PubMed

Azar, Basel; Eckert, Steve; Kunkela, Josef; Ingr, Tomaš; Mounajjed, Radek

2018-01-01

This study aimed to compare the vertical marginal gap of teeth restored with lithium disilicate crowns fabricated using CAD/CAM or by pressed ceramic approach. Twenty mandibular third molar teeth were collected after surgical extractions and prepared to receive full veneer crowns. Teeth were optically scanned and lithium disilicate blocks were used to fabricate crowns using CAD/CAM technique. Polyvinyl siloxane impressions of the prepared teeth were made and monolithic pressed lithium disilicate crowns were fabricated. The marginal gap was measured using optical microscope at 200× magnification (Keyence VHX-5000, Japan). Statistical analysis was performed using Wilcoxon test. The lithium disilicate pressed crowns had significantly smaller (p = 0.006) marginal gaps (38 ± 12 μm) than the lithium disilicate CAD/CAM crowns (45 ± 12 μm). This research indicates that lithium disilicate crowns fabricated with the press technique have measurably smaller marginal gaps compared with those fabricated with CAD/CAM technique within in vitro environments. The marginal gaps achieved by the crowns across all groups were within a clinically acceptable range.

Mounting ground sections of teeth: Cyanoacrylate adhesive versus Canada balsam.

PubMed

Vangala, Manogna Rl; Rudraraju, Amrutha; Subramanyam, R V

2016-01-01

Hard tissues can be studied by either decalcification or by preparing ground sections. Various mounting media have been tried and used for ground sections of teeth. However, there are very few studies on the use of cyanoacrylate adhesive as a mounting medium. The aim of our study was to evaluate the efficacy of cyanoacrylate adhesive (Fevikwik™) as a mounting medium for ground sections of teeth and to compare these ground sections with those mounted with Canada balsam. Ground sections were prepared from twenty extracted teeth. Each section was divided into two halves and mounted on one slide, one with cyanoacrylate adhesive (Fevikwik™) and the other with Canada balsam. Scoring for various features in the ground sections was done by two independent observers. Statistical analysis using Student's t-test (unpaired) of average scores was performed for each feature observed. No statistically significant difference was found between the two for most of the features. However, cyanoacrylate was found to be better than Canada balsam for observing striae of Retzius (P < 0.0205), enamel lamellae (P < 0.036), dentinal tubules (P < 0.0057), interglobular dentin (P < 0.0001), sclerotic dentin - transmitted light (P < 0.00001), sclerotic dentin - polarized light (P < 0.0002) and Sharpey's fibers (P < 0.0004). This initial study shows that cyanoacrylate is better than Canada balsam for observing certain features of ground sections of teeth. However, it remains to be seen whether it will be useful for studying undecalcified sections of carious teeth and for soft tissue sections.

Influence of ferrule preparation with or without glass fiber post on fracture resistance of endodontically treated teeth

PubMed Central

de LIMA, Alexandra Furtado; SPAZZIN, Aloísio Oro; GALAFASSI, Daniel; CORRER-SOBRINHO, Lourenço; CARLINI-JÚNIOR, Bruno

2010-01-01

Objective This study evaluated the effect of ferrule preparation (Fp) on the fracture resistance of endodontically treated teeth, restored with composite resin cores with or without glass fiber posts. Material and Methods Forty-four bovine teeth were sectioned 19 or 17 mm (2 mm ferrule) from the apex, endodontically treated and assigned to four groups (n = 11): Group 1: Fp and post; Group 2: Fp and without post; Group 3: without Fp and with post; Group 4: without Fp and without post. All specimens were restored with composite resin core and metal crown. Specimens were subjected to fracture resistance testing in a universal testing machine at a crosshead speed of 0.5 mm/min. The data were analyzed by two-way ANOVA and Tukey’s tests (α=0.05). Results The mean fracture resistance values were as follows: Group 1: 573.3 N; Group 2: 552.5 N; Group 3: 275.3 N; Group 4: 258.6 N. Significantly higher fracture resistance was found for the groups with Fp (p<0.001). Conclusion There was no statistically significant interaction between the "Fp" and "post" factors (p = 0.954). The ferrule preparation increased the fracture resistance of endodontically treated teeth. However, the use of glass fiber post showed no significant influence on the fracture resistance. PMID:20835570

A comparison of temperature increases produced by "premium" and "standard" diamond burs: An in-vitro study.

PubMed

Segal, Pnina; Sap, Danny; Ben-Amar, Ariel; Levartovsky, Shifra; Matalon, Shlomo

2016-02-01

Vital tooth preparations may cause irreversible thermal damage to the pulp. The manufacturing techniques of dental burs may decrease heat production and minimize the risk of overheating and trauma to the dental pulp. Strauss (Raanana, Israel) has introduced "premium" diamond burs, claiming superior efficiency and longevity. We sought to determine the safest preparation methods by performing a comparison of intrapulpal temperature increases caused with "standard" and "premium" burs. Three types of diamond burs (F1R, F21R, and K2) were tested on extracted human teeth (n = 8 teeth per bur type). Premium and standard manufacturing techniques were compared for each bur type (n = 24 teeth per group; total 48 teeth). An intrapulpal thermocouple was used to measure the temperature during the procedure. Comparisons were analyzed with the t test and one-way ANOVA. P ≤ .05 was considered significant. All premium burs demonstrated lower temperature increases compared to the standard burs (P ≤ .001 for F21R and K2, P = .086 for F1R). The temperature increases with premium burs were similar for different bur shapes, but the temperature increases with standard burs depended on the bur shape (P < .001). Using premium diamond burs for tooth preparation may reduce the risk of pulp tissue damage, and thus reduce postoperative pulp-associated complications.

Teaching an engine-driven preparation technique to undergraduates: initial observations.

PubMed

Hänni, S; Schönenberger, K; Peters, O A; Barbakow, F

2003-07-01

This paper describes the initial experiences following the introduction of a rotary engine-driven preparation technique into the undergraduate endodontic programme at the Zurich University Dental Centre. Forty third-year students practised the ProFile.04 (PF.04) technique between January and July 2001 in a preclinical course. Between November 2001 and February 2002, 20 of these students (Group A) root-treated 51 teeth in their clinical course using either PF.04, the balanced force technique (BFT) or a combination of both. The second group of 20 students (Group B) similarly treated another 36 randomly selected teeth between April and July 2002. Types of teeth treated by the students and the canal preparation techniques were recorded. The students also completed a short questionnaire, evaluating their opinions of the new course. Of the 87 teeth endodontically treated during the clinical course, 34, 14 and 39 were shaped using PF.04 alone, a combination of PF.04 and BFT and BFT alone, respectively. No rotary instruments were fractured during the 1-year clinical course, although some instruments were fractured during the preclinical laboratory course. Overall, the students rated the rotary technique as positive. A rotary technique was successfully introduced into an undergraduate endodontic programme (this will be continued in the foreseeable future). However, the continuity between the preclinical and the clinical courses was poor as a result of the constraints of the general teaching programme.

The Retentive Strength of Cemented Zirconium Oxide Crowns after Dentin Pretreatment with Desensitizing Paste Containing 8% Arginine and Calcium Carbonate

PubMed Central

Pilo, Raphael; Harel, Noga; Nissan, Joseph; Levartovsky, Shifra

2016-01-01

The effect of dentin pretreatment with Desensitizing Paste containing 8% arginine and calcium carbonate on the retention of zirconium oxide (Y-TZP) crowns was tested. Forty molar teeth were mounted and prepared using a standardized protocol. Y-TZP crowns were produced using computer-aided design and computer-aided manufacturing (CAD-CAM) technology. The 40 prepared teeth were either pretreated with Desensitizing Paste or not pretreated. After two weeks, each group was subdivided into two groups, cemented with either Resin Modified Glass Ionomer Cement (RMGIC) or Self Adhesive Resin Cement (SARC)). Prior to cementation, the surface areas of the prepared teeth were measured. After aging, the cemented crown-tooth assemblies were tested for retentive strength using a universal testing machine. The debonded surfaces of the teeth and crowns were examined microscopically at 10× magnification. Pretreating the dentin surfaces with Desensitizing Paste prior to cementation did not affect the retention of the Y-TZP crowns. The retentive values for RMGIC (3.04 ± 0.77 MPa) were significantly higher than those for SARC (2.28 ± 0.58 MPa). The predominant failure modes for the RMGIC and SARC were adhesive cement-dentin and adhesive cement-crown, respectively. An 8.0% arginine and calcium carbonate in-office desensitizing paste can be safely used to reduce post-cementation sensitivity without reducing the retentive strength of Y-TZP crowns. PMID:27023532

The Retentive Strength of Cemented Zirconium Oxide Crowns after Dentin Pretreatment with Desensitizing Paste Containing 8% Arginine and Calcium Carbonate.

PubMed

Pilo, Raphael; Harel, Noga; Nissan, Joseph; Levartovsky, Shifra

2016-03-25

The effect of dentin pretreatment with Desensitizing Paste containing 8% arginine and calcium carbonate on the retention of zirconium oxide (Y-TZP) crowns was tested. Forty molar teeth were mounted and prepared using a standardized protocol. Y-TZP crowns were produced using computer-aided design and computer-aided manufacturing (CAD-CAM) technology. The 40 prepared teeth were either pretreated with Desensitizing Paste or not pretreated. After two weeks, each group was subdivided into two groups, cemented with either Resin Modified Glass Ionomer Cement (RMGIC) or Self Adhesive Resin Cement (SARC)). Prior to cementation, the surface areas of the prepared teeth were measured. After aging, the cemented crown-tooth assemblies were tested for retentive strength using a universal testing machine. The debonded surfaces of the teeth and crowns were examined microscopically at 10× magnification. Pretreating the dentin surfaces with Desensitizing Paste prior to cementation did not affect the retention of the Y-TZP crowns. The retentive values for RMGIC (3.04 ± 0.77 MPa) were significantly higher than those for SARC (2.28 ± 0.58 MPa). The predominant failure modes for the RMGIC and SARC were adhesive cement-dentin and adhesive cement-crown, respectively. An 8.0% arginine and calcium carbonate in-office desensitizing paste can be safely used to reduce post-cementation sensitivity without reducing the retentive strength of Y-TZP crowns.

[Quantitive study of interleukin 1beta in periapical exudates of chronic periapical periodontitis in the course of root canal therapy].

PubMed

Yan, Pei-fang; Liang, Jing-ping; Chen, Wei-min; Gu, Shen-sheng

2007-06-01

To evaluate the relationship between IL-1beta and clinical findings of chronic apical periodontitis and to explore the function of IL-1beta during the endodontic interappointment flare-ups. Periapical exudates samples were obtained from 19 teeth suffering from endodontic flare-ups after root canal preparation and 20 teeth without any symptoms and signs at the second visit after root canal preparation. The levels of IL-1beta were determined by ELISA and the data was analyzed by SAS6.12 software package. Significantly higher levels of IL-1beta were found in periapical exudates from teeth suffering from endodontic flare-ups than that before canal preparation(P<0.001). The mean IL-1beta levels significantly decreased following the endodontic therapy if there were no symptom at the second visit (P<0.001). The level of IL-1beta in the exudates of root canals were related with the exist of infection which might take an active part in the occurrence of endodontic interappointment flare-up.

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

PubMed

Kanaparthy, Aruna; Kanaparthy, Rosaiah

2016-05-01

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

Stability of interceptive/corrective orthodontic treatment for tooth ankylosis and Class II mandibular deficiency: A case report with 10 years follow-up.

PubMed

Guimarães, Carlos Henrique; Henriques, José Fernando Castanha; Janson, Guilherme; Moura, Wilana S

2015-01-01

The purpose of this article is to present the treatment of a 8-year-old boy with tooth ankylosis in teeth 85 and Class II division 1 malocclusion and to report a 10-year follow-up result. The patient was initially treated with a sagittal removable appliance, followed by an eruption guidance appliance and braces. The interceptive orthodontic treatment performed to recover the space lost by ankylosis of a deciduous tooth allowed a spontaneous eruption and prevented progression of the problem. The use of an eruption-guidance appliance corrected the dentoskeletal Class II, thus improving the patient's appearance. Besides the treatment producing a good occlusal relationship with the Class I molar, the correction of the overjet and overbite was stable over a ten-year period.

An In Vitro Study on the Effects of Post-Core Design and Ferrule on the Fracture Resistance of Endodontically Treated Maxillary Central Incisors.

PubMed

Sreedevi, S; Sanjeev, R; Raghavan, Rekha; Abraham, Anna; Rajamani, T; Govind, Girish Kumar

2015-08-01

Endodontically treated teeth have significantly different physical and mechanical properties compared to vital teeth and are more prone to fracture. The study aims to compare the fracture resistance of endodontically treated teeth with and without post reinforcement, custom cast post-core and prefabricated post with glass ionomer core and to evaluate the ferrule effect on endodontically treated teeth restored with custom cast post-core. A total of 40 human maxillary central incisors with similar dimensions devoid of any root caries, restorations, previous endodontic treatment or cracks were selected from a collection of stored extracted teeth. An initial silicone index of each tooth was made. They were treated endodontically and divided into four groups of ten specimens each. Their apical seal was maintained with 4 mm of gutta-percha. Root canal preparation was done and then post core fabrication was done. The prepared specimens were subjected to load testing using a computer coordinated UTM. The fracture load results were then statistically analyzed. One-way ANOVA was followed by paired t-test. 1. Reinforcement of endodontically treated maxillary central incisors with post and core, improved their fracture resistance to be at par with that of endodontically treated maxillary central incisor, with natural crown. 2. The fracture resistance of endodontically treated maxillary central incisors is significantly increased when restored with custom cast post-core and 2 mm ferrule. With 2 mm ferrule, teeth restored with custom cast post-core had a significantly higher fracture resistance than teeth restored with custom cast post-core or prefabricated post and glass ionomer core without ferrule.

The Effect of Cavity Design on Fracture Resistance and Failure Pattern in Monolithic Zirconia Partial Coverage Restorations - An In vitro Study.

PubMed

Harsha, Madhavareddy Sri; Praffulla, Mynampati; Babu, Mandava Ramesh; Leneena, Gudugunta; Krishna, Tejavath Sai; Divya, G

2017-05-01

Cavity preparations of posterior teeth have been frequently associated with decreased fracture strength of the teeth. Choosing the correct indirect restoration and the cavity design when restoring the posterior teeth i.e., premolars was difficult as it involves aesthetic, biomechanical and anatomical considerations. To evaluate the fracture resistance and failure pattern of three different cavity designs restored with monolithic zirconia. Human maxillary premolars atraumatically extracted for orthodontic reasons were chosen. A total of 40 teeth were selected and divided into four groups (n=10). Group I-Sound teeth (control with no preparation). Group II-MOD Inlay, Group III-Partial Onlay, Group IV-Complete Onlay. Restorations were fabricated with monolithic partially sintered zirconia CAD (SAGEMAX- NexxZr). All the 30 samples were cemented using Multilink Automix (Ivoclar) and subjected to fracture resistance testing using Universal Testing Machine (UTM) (Instron) with a steel ball of 3.5 mm diameter at crosshead speed of 0.5 mm/minute. Stereomicroscope was used to evaluate the modes of failure of the fractured specimen. Fracture resistance was tested using parametric one way ANOVA test, unpaired t-test and Tukey test. Fracture patterns were assessed using non-parametric Chi-square test. Group IV (Complete Onlay) presented highest fracture resistance and showed statistical significant difference. Group II (MOD Inlay) and Group III (Partial Onlay) showed significantly lower values than the Group I (Sound teeth). However, Groups I, II and III presented no significant difference from each other. Coming to the modes of failure, Group II (MOD Inlay) and Group III (Partial Onlay) presented mixed type of failures; Group IV (Complete Onlay) demonstrated 70% Type I failures. Of the three cavity designs evaluated, Complete Onlay had shown a significant increase in the fracture resistance than the Sound teeth.

Similar influence of stabilized alkaline and neutral sodium hypochlorite solutions on the fracture resistance of root canal-treated bovine teeth.

PubMed

Souza, Erick Miranda; Calixto, Amanda Martins; Lima, Camila Nara E; Pappen, Fernanda Geraldo; De-Deus, Gustavo

2014-10-01

Stabilizing sodium hypochlorite (NaOCl) at an alkaline pH is proposed to increase solution stability and tissue dissolution ability; however, a reduction on the flexural strength of dentin discs has been found to be a side effect. This study sought to determine whether a stabilized alkaline NaOCl reduces the fracture resistance of root canal-treated bovine teeth after root canal preparation compared with a neutral solution counterpart. The 4 anterior incisors were removed from 20 mandibular bovine jaws, and each 1 was randomly assigned to 1 of 4 groups (20 teeth each). Teeth were prepared with a sequence of 6 K-type files. The following experimental groups received a different irrigation regimen: G1: distilled water (negative control), G2: 5% NaOCl at a pH of 7.2, and G3: 5% NaOCl at a pH of 12.8; in the positive control group (G4), teeth remained untreated. The time of contact and volume of solution were carefully standardized. After bone and periodontal ligament simulation, teeth were subjected to a fracture resistance test. A significant difference was observed among the 4 groups tested (analysis of variance, P < .05). The 5% NaOCl groups (G2 and G3) presented significantly lower resistance to fracture than the control (G1 and G4) (Tukey test, P < .05). Both NaOCl solutions similarly reduced the fracture resistance at approximately 30% (Tukey test, P > .05). No differences were observed between positive and negative control groups (Tukey test, P > .05). Stabilized alkaline and neutral NaOCl solutions similarly reduced the fracture resistance of root canal-treated bovine teeth by about 30%. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

[Women's approach to childhood toothache, abdominal ache and earache].

PubMed

Efe, Emine; Öncel, Selma; Yilmaz, Mualla

2012-01-01

This study was conducted to determine women's about attitudes child's teeth, abdomen and ear ache. Those who had lived in Antalya that 6 number primary health care center between March-May 2004 were enrolled in the study. As data collecting tools. A questionnaire prepared by the authors. This study was determined that 29.2 % of the mothers carried out mixture who had prepared at home to child's abdomen and foot base; 30.3 % were to put breast milk childs' ear; 38.9 % were placed aspirin, salt and salts of lemon to childs' teeth ache. The majority of the women make a wrong practices child that teeth, abdomen and ear ache. This traditional practice effecting factors were the women's educational status and age. The results of the study that education about child care, common health problems and incorrect applications shoud be given to women by nurse.

The evolution of menstruation: a new model for genetic assimilation: explaining molecular origins of maternal responses to fetal invasiveness.

PubMed

Emera, Deena; Romero, Roberto; Wagner, Günter

2012-01-01

Why do humans menstruate while most mammals do not? Here, we present our answer to this long-debated question, arguing that (i) menstruation occurs as a mechanistic consequence of hormone-induced differentiation of the endometrium (referred to as spontaneous decidualization, or SD); (ii) SD evolved because of maternal-fetal conflict; and (iii) SD evolved by genetic assimilation of the decidualization reaction, which is induced by the fetus in non-menstruating species. The idea that menstruation occurs as a consequence of SD has been proposed in the past, but here we present a novel hypothesis on how SD evolved. We argue that decidualization became genetically stabilized in menstruating lineages, allowing females to prepare for pregnancy without any signal from the fetus. We present three models for the evolution of SD by genetic assimilation, based on recent advances in our understanding of the mechanisms of endometrial differentiation and implantation. Testing these models will ultimately shed light on the evolutionary significance of menstruation, as well as on the etiology of human reproductive disorders like endometriosis and recurrent pregnancy loss. Copyright © 2012 WILEY Periodicals, Inc.

Replacing Heavily Damaged Teeth by Third Molar Autotransplantation With the Use of Cone-Beam Computed Tomography and Rapid Prototyping.

PubMed

Verweij, Jop P; Anssari Moin, David; Wismeijer, Daniel; van Merkesteyn, J P Richard

2017-09-01

This article describes the autotransplantation of third molars to replace heavily damaged premolars and molars. Specifically, this article reports on the use of preoperative cone-beam computed tomographic planning and 3-dimensional (3D) printed replicas of donor teeth to prepare artificial tooth sockets. In the present case, an 18-year-old patient underwent autotransplantation of 3 third molars to replace 1 premolar and 2 molars that were heavily damaged after trauma. Approximately 1 year after the traumatic incident, autotransplantation with the help of 3D planning and rapid prototyping was performed. The right maxillary third molar replaced the right maxillary first premolar. The 2 mandibular wisdom teeth replaced the left mandibular first and second molars. During the surgical procedure, artificial tooth sockets were prepared with the help of 3D printed donor tooth copies to prevent iatrogenic damage to the actual donor teeth. These replicas of the donor teeth were designed based on the preoperative cone-beam computed tomogram and manufactured with the help of 3D printing techniques. The use of a replica of the donor tooth resulted in a predictable and straightforward procedure, with extra-alveolar times shorter than 2 minutes for all transplantations. The transplanted teeth were placed in infraocclusion and fixed with a suture splint. Postoperative follow-up showed physiologic integration of the transplanted teeth and a successful outcome for all transplants. In conclusion, this technique facilitates a straightforward and predictable procedure for autotransplantation of third molars. The use of printed analogues of the donor teeth decreases the risk of iatrogenic damage and the extra-alveolar time of the transplanted tooth is minimized. This facilitates a successful outcome. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Evolutionary and Biological Implications of Dental Mesial Drift in Rodents: The Case of the Ctenodactylidae (Rodentia, Mammalia)

PubMed Central

Gomes Rodrigues, Helder; Solé, Floréal; Charles, Cyril; Tafforeau, Paul; Vianey-Liaud, Monique; Viriot, Laurent

2012-01-01

Dental characters are importantly used for reconstructing the evolutionary history of mammals, because teeth represent the most abundant material available for the fossil species. However, the characteristics of dental renewal are presently poorly used, probably because dental formulae are frequently not properly established, whereas they could be of high interest for evolutionary and developmental issues. One of the oldest rodent families, the Ctenodactylidae, is intriguing in having longstanding disputed dental formulae. Here, we investigated 70 skulls among all extant ctenodactylid genera (Ctenodactylus, Felovia, Massoutiera and Pectinator) by using X-ray conventional and synchrotron microtomography in order to solve and discuss these dental issues. Our study clearly indicates that Massoutiera, Felovia and Ctenodactylus differ from Pectinator not only by a more derived dentition, but also by a more derived eruptive sequence. In addition to molars, their dentition only includes the fourth deciduous premolars, and no longer bears permanent premolars, conversely to Pectinator. Moreover, we found that these premolars are lost during adulthood, because of mesial drift of molars. Mesial drift is a striking mechanism involving migration of teeth allowed by both bone remodeling and dental resorption. This dental innovation is to date poorly known in rodents, since it is only the second report described. Interestingly, we noted that dental drift in rodents is always associated with high-crowned teeth favoring molar size enlargement. It can thus represent another adaptation to withstand high wear, inasmuch as these rodents inhabit desert environments where dust is abundant. A more accurate study of mesial drift in rodents would be very promising from evolutionary, biological and orthodontic points of view. PMID:23185576

Premature primary tooth eruption in cognitive/motor-delayed ADNP-mutated children

PubMed Central

Gozes, I; Van Dijck, A; Hacohen-Kleiman, G; Grigg, I; Karmon, G; Giladi, E; Eger, M; Gabet, Y; Pasmanik-Chor, M; Cappuyns, E; Elpeleg, O; Kooy, R F; Bedrosian-Sermone, S

2017-01-01

A major flaw in autism spectrum disorder (ASD) management is late diagnosis. Activity-dependent neuroprotective protein (ADNP) is a most frequent de novo mutated ASD-related gene. Functionally, ADNP protects nerve cells against electrical blockade. In mice, complete Adnp deficiency results in dysregulation of over 400 genes and failure to form a brain. Adnp haploinsufficiency results in cognitive and social deficiencies coupled to sex- and age-dependent deficits in the key microtubule and ion channel pathways. Here, collaborating with parents/caregivers globally, we discovered premature tooth eruption as a potential early diagnostic biomarker for ADNP mutation. The parents of 44/54 ADNP-mutated children reported an almost full erupted dentition by 1 year of age, including molars and only 10 of the children had teeth within the normal developmental time range. Looking at Adnp-deficient mice, by computed tomography, showed significantly smaller dental sacs and tooth buds at 5 days of age in the deficient mice compared to littermate controls. There was only trending at 2 days, implicating age-dependent dysregulation of teething in Adnp-deficient mice. Allen Atlas analysis showed Adnp expression in the jaw area. RNA sequencing (RNAseq) and gene array analysis of human ADNP-mutated lymphoblastoids, whole-mouse embryos and mouse brains identified dysregulation of bone/nervous system-controlling genes resulting from ADNP mutation/deficiency (for example, BMP1 and BMP4). AKAP6, discovered here as a major gene regulated by ADNP, also links cognition and bone maintenance. To the best of our knowledge, this is the first time that early primary (deciduous) teething is related to the ADNP syndrome, providing for early/simple diagnosis and paving the path to early intervention/specialized treatment plan. PMID:28221363

Emergency management of dental trauma: knowledge of Hong Kong primary and secondary school teachers.

PubMed

Young, Cecilia; Wong, K Y; Cheung, L K

2012-10-01

OBJECTIVES. To investigate the level of knowledge about emergency management of dental trauma among Hong Kong primary and secondary school teachers. DESIGN. Questionnaire survey. SETTING. A teachers' union that unites 90% of teachers in Hong Kong. PARTICIPANTS. Randomly selected primary and secondary school teachers. RESULTS. Only 32.8% of respondents correctly stated that a person sustaining dental trauma should go to dentists directly. In all, 73.1% of teachers correctly stated that a dental trauma patient should go for treatment immediately. Only 32.5% knew that a fractured tooth should be put in liquid. Even fewer (23.2%) realised that the displaced tooth should be repositioned back to the original position. Relatively more respondents (74.7%) understood that an avulsed baby tooth should not be put back. Disappointingly, only 16.3% of teachers knew that an avulsed permanent tooth should be replanted. Furthermore, only 29.6% of teachers thought that they were able to distinguish between deciduous teeth and permanent teeth, whilst 20.4% correctly identified at least one of the appropriate mediums: milk, physiological saline or saliva, for storing an avulsed tooth. Teachers who previously received first-aid training with dental content or acquired dental injury information from other sources, scored significantly higher than teachers without such training or acquired information. CONCLUSION. The knowledge on emergency management of dental trauma among primary and secondary school teachers in Hong Kong is insufficient, particularly on the handling of permanent tooth avulsion and the appropriate storage medium for avulsed teeth. Receipt of first-aid training with dental contents and acquisition of dental injury information from other sources were positively correlated with knowledge in managing dental trauma.

Effect of the angle of apical resection on apical leakage, measured with a computerized fluid filtration device.

PubMed

Garip, Hasan; Garip, Yıldız; Oruçoğlu, Hasan; Hatipoğlu, Seda

2011-03-01

We determined the effect of the angle of apical resection on apical leakage using a computerized fluid filtration meter with a laser system and a digital air pressure regulator in 46 extracted single-rooted human teeth. Orthograde endodontic treatment was performed. The root canals were prepared up to a size 50 K-type file with 17% EDTA solution (Roth International, Chicago, IL) and 5% NaOCl solution as the irrigant. Gates Glidden burs (Maillefer Instruments, Ballaigues, Switzerland) were used to flare the coronal two thirds of the canal. All canals were dried with paper points and then obturated using cold lateral condensation (except for the positive controls) of gutta-percha points and AH plus (Dentsply DeTrey, Konstanz, Germany). All 40 roots were sectioned 3 mm from the apex. Forty teeth were assigned randomly into 1 of 4 experimental groups of 10 teeth each: in group 1, the teeth were resected apically (90° angle) and the cavities were obturated with mineral trioxide aggregate (MTA); in group 2, after apical resection (90° angle), a root-end cavity was prepared using ultrasonic diamond retrotips and the cavities were obturated with MTA; in group 3, the teeth were resected apically (∼45° angle) and the cavities were obturated with MTA; and in group 4, after apical resection (∼45° angle), a root-end cavity was prepared using ultrasonic diamond retrotips and the cavities were obturated with MTA. An additional 6 teeth were used as controls (3 each, negative and positive controls). Apical leakage was measured using a computerized fluid filtration meter with a laser system. The mean apical microleakage was 2.0 ± 0.4 × 10(-4), 1.6 ± 0.6 × 10(-4), 1.6 ± 0.9 × 10(-4), and 1.8 ± 0.7 × 10(-4) μL/cmH(2)O/min(-1) at 1.2 atm, in groups 1 to 4, respectively. Although the mean apical microleakage was greater in group 1, the differences among the 4 groups were not statistically significant (P > .05). The results of these in vitro studies showed that when an adequate retrograde cavity depth is prepared, variation in the root-end cutting angle does not necessarily cause any difference in microleakage. Copyright © 2011 Mosby, Inc. All rights reserved.

CRITICAL ANALYSIS OF ARTIFICIAL TEETH FOR ENDODONTIC TEACHING

PubMed Central

Nassri, Maria Renata Giazzi; Carlik, Jaime; da Silva, Camila Roberta Nepomuceno; Okagawa, Renata Elisa; Lin, Suzy

2008-01-01

The purpose of this study was to evaluate the use of artificial teeth for endodontic teaching. A questionnaire was prepared and submitted to 18 professors of Endodontics from different Brazilian universities to evaluate the following features of five cloudy resin artificial teeth: internal and external anatomy; coronal chambers regarding their size, shape and canal path; root canal regarding their size, shape and position; fulfillment of the pulp chamber and root canals by considering the texture, quantity, color, and ease of handling; resin hardness and visualization of the radiographic image. The results presented favorable opinions, in terms of internal and external anatomy, coronal pulp chambers and root canal and handling and radiographic imaging. The contents of the pulp space and hardness of the teeth were considered satisfactory. The average grade assigned to the artificial tooth quality was 8.4, in a 0-10 scale. In conclusion, the artificial teeth have potential to replace the natural teeth in endodontic teaching; however, improvements are still necessary to reach a better quality model. PMID:19089288

Critical analysis of artificial teeth for endodontic teaching.

PubMed

Nassri, Maria Renata Giazzi; Carlik, Jaime; da Silva, Camila Roberta Nepomuceno; Okagawa, Renata Elisa; Lin, Suzy

2008-01-01

The purpose of this study was to evaluate the use of artificial teeth for endodontic teaching. A questionnaire was prepared and submitted to 18 professors of Endodontics from different Brazilian universities to evaluate the following features of five cloudy resin artificial teeth: internal and external anatomy; coronal chambers regarding their size, shape and canal path; root canal regarding their size, shape and position; fulfillment of the pulp chamber and root canals by considering the texture, quantity, color, and ease of handling; resin hardness and visualization of the radiographic image. The results presented favorable opinions, in terms of internal and external anatomy, coronal pulp chambers and root canal and handling and radiographic imaging. The contents of the pulp space and hardness of the teeth were considered satisfactory. The average grade assigned to the artificial tooth quality was 8.4, in a 0-10 scale. In conclusion, the artificial teeth have potential to replace the natural teeth in endodontic teaching; however, improvements are still necessary to reach a better quality model.

Regenerative Endodontic Therapy in a Single Visit Using Platelet-rich Plasma and Biodentine in Necrotic and Asymptomatic Immature Molar Teeth: A Report of 3 Cases.

PubMed

Topçuoğlu, Gamze; Topçuoğlu, Hüseyin Sinan

2016-09-01

This report describes 3 successful single-visit regenerative endodontic therapy cases using platelet-rich plasma (PRP) and Biodentine (Septodont, Saint Maurdes Fossés, France) for 3 immature mandibular molar teeth, all with necrotic pulp, in 2 children aged 8 years and 1 aged 9 years. Three teeth were separately diagnosed as having a necrotic pulp. After preparation of the access cavity under rubber dam isolation, the necrotic pulp was removed, and each canal was irrigated with 2.5% sodium hypochlorite, sterile saline, and 17% EDTA solutions. Freshly prepared PRP was injected into each canal up to the cementoenamel junction, and Biodentine was placed directly over the PRP clot. Each access cavity was then restored with composite resin. Follow-up clinical examinations revealed negative responses to cold and electric pulp tests. None of the treated teeth were sensitive to percussion or palpation. Radiographic examination showed continued thickening of root canal walls and apical closure of the root apex of each tooth. Single-visit regenerative endodontic therapy can be considered in necrotic and asymptomatic immature permanent teeth. PRP and Biodentine may serve as scaffold and barrier materials in regenerative endodontic procedures. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

A novel computer-aided method to fabricate a custom one-piece glass fiber dowel-and-core based on digitized impression and crown preparation data.

PubMed

Chen, Zhiyu; Li, Ya; Deng, Xuliang; Wang, Xinzhi

2014-06-01

Fiber-reinforced composite dowels have been widely used for their superior biomechanical properties; however, their preformed shape cannot fit irregularly shaped root canals. This study aimed to describe a novel computer-aided method to create a custom-made one-piece dowel-and-core based on the digitization of impressions and clinical standard crown preparations. A standard maxillary die stone model containing three prepared teeth each (maxillary lateral incisor, canine, premolar) requiring dowel restorations was made. It was then mounted on an average value articulator with the mandibular stone model to simulate natural occlusion. Impressions for each tooth were obtained using vinylpolysiloxane with a sectional dual-arch tray and digitized with an optical scanner. The dowel-and-core virtual model was created by slicing 3D dowel data from impression digitization with core data selected from a standard crown preparation database of 107 records collected from clinics and digitized. The position of the chosen digital core was manually regulated to coordinate with the adjacent teeth to fulfill the crown restorative requirements. Based on virtual models, one-piece custom dowel-and-cores for three experimental teeth were milled from a glass fiber block with computer-aided manufacturing techniques. Furthermore, two patients were treated to evaluate the practicality of this new method. The one-piece glass fiber dowel-and-core made for experimental teeth fulfilled the clinical requirements for dowel restorations. Moreover, two patients were treated to validate the technique. This novel computer-aided method to create a custom one-piece glass fiber dowel-and-core proved to be practical and efficient. © 2013 by the American College of Prosthodontists.

Accuracy assessment of high frequency 3D ultrasound for digital impression-taking of prepared teeth

NASA Astrophysics Data System (ADS)

Heger, Stefan; Vollborn, Thorsten; Tinschert, Joachim; Wolfart, Stefan; Radermacher, Klaus

2013-03-01

Silicone based impression-taking of prepared teeth followed by plaster casting is well-established but potentially less reliable, error-prone and inefficient, particularly in combination with emerging techniques like computer aided design and manufacturing (CAD/CAM) of dental prosthesis. Intra-oral optical scanners for digital impression-taking have been introduced but until now some drawbacks still exist. Because optical waves can hardly penetrate liquids or soft-tissues, sub-gingival preparations still need to be uncovered invasively prior to scanning. High frequency ultrasound (HFUS) based micro-scanning has been recently investigated as an alternative to optical intra-oral scanning. Ultrasound is less sensitive against oral fluids and in principal able to penetrate gingiva without invasively exposing of sub-gingival preparations. Nevertheless, spatial resolution as well as digitization accuracy of an ultrasound based micro-scanning system remains a critical parameter because the ultrasound wavelength in water-like media such as gingiva is typically smaller than that of optical waves. In this contribution, the in-vitro accuracy of ultrasound based micro-scanning for tooth geometry reconstruction is being investigated and compared to its extra-oral optical counterpart. In order to increase the spatial resolution of the system, 2nd harmonic frequencies from a mechanically driven focused single element transducer were separated and corresponding 3D surface models were calculated for both fundamentals and 2nd harmonics. Measurements on phantoms, model teeth and human teeth were carried out for evaluation of spatial resolution and surface detection accuracy. Comparison of optical and ultrasound digital impression taking indicate that, in terms of accuracy, ultrasound based tooth digitization can be an alternative for optical impression-taking.

Potential of desensitizing toothpastes to reduce the hydrogen peroxide diffusion in teeth with cervical lesions.

PubMed

Dávila-Sánchez, Andrés; Montenegro, Andrés Fernando; Alfonso, Arana-Gordillo; Farago, Paulo Vitor; Loguercio, Alessandro D; Reis, Alessandra

2016-06-01

To evaluate the occlusive potential of four toothpastes by atomic force microscopy (AFM) before and after bleaching and quantify the hydrogen peroxide (HP) diffusion into the pulp chamber after application of desensitizing toothpastes in teeth with cervical lesions. In 52 human extracted premolars, 2-mm deep artificial cervical lesions (ACL) were prepared and rinsed with EDTA for 10 seconds. Then teeth were adapted in a brushing machine and brushed with one of the following toothpastes [Regular toothpaste with no occlusive compounds Colgate Cavity Protection (CP), Oral-B Pro Health (OB), Colgate ProRelief (PR) and Sensodyne Rapid Relief (RR)] under constant loading (250 g; 4.5 cycles/seconds; 3 minutes). In 13 teeth (control group), no artificial cervical lesion was prepared. After that, the teeth were bleached with 35% HP with three 15-minute applications. The HP diffusion was measured spectrophotometrically as a stable red product based on HP reaction with 4-aminoanthipyrine and phenol in presence of peroxidase, at a wavelength of 510 nm and the dentin surfaces of ACL were evaluated before and after bleaching by AFM. Data was statistically analyzed by one-way ANOVA and Tukey's test (alpha = 0.05). In the AFM images, some modifications of the dentin surface were observed after application of OB and RR. However, only for RR the formation of a surface deposit was produced, which occluded the majority of the dentin tubules. Also, only for RR, this deposit was not modified/removed by bleaching. Despite this, all groups with ACL showed higher HP penetration than sound teeth, regardless of the toothpaste used (P < 0.001).

Mounting ground sections of teeth: Cyanoacrylate adhesive versus Canada balsam

PubMed Central

Vangala, Manogna RL; Rudraraju, Amrutha; Subramanyam, RV

2016-01-01

Introduction: Hard tissues can be studied by either decalcification or by preparing ground sections. Various mounting media have been tried and used for ground sections of teeth. However, there are very few studies on the use of cyanoacrylate adhesive as a mounting medium. Aims: The aim of our study was to evaluate the efficacy of cyanoacrylate adhesive (Fevikwik™) as a mounting medium for ground sections of teeth and to compare these ground sections with those mounted with Canada balsam. Materials and Methods: Ground sections were prepared from twenty extracted teeth. Each section was divided into two halves and mounted on one slide, one with cyanoacrylate adhesive (Fevikwik™) and the other with Canada balsam. Scoring for various features in the ground sections was done by two independent observers. Statistical Analysis Used: Statistical analysis using Student's t-test (unpaired) of average scores was performed for each feature observed. Results: No statistically significant difference was found between the two for most of the features. However, cyanoacrylate was found to be better than Canada balsam for observing striae of Retzius (P < 0.0205), enamel lamellae (P < 0.036), dentinal tubules (P < 0.0057), interglobular dentin (P < 0.0001), sclerotic dentin – transmitted light (P < 0.00001), sclerotic dentin – polarized light (P < 0.0002) and Sharpey's fibers (P < 0.0004). Conclusions: This initial study shows that cyanoacrylate is better than Canada balsam for observing certain features of ground sections of teeth. However, it remains to be seen whether it will be useful for studying undecalcified sections of carious teeth and for soft tissue sections. PMID:27194857

The pediatric mandible: II. Management of traumatic injury or fracture.

PubMed

Smartt, James M; Low, David W; Bartlett, Scott P

2005-08-01

After studying this article, the participant should be able to: 1. Describe the changing epidemiology of mandibular fractures in children and adolescents. 2. Discuss the appropriate use of internal fixation in the treatment of pediatric mandibular fractures. 3. Describe the difficulties posed by the deciduous dentition in the use of interdental wiring. 4. Understand reasons why techniques specific to adult fractures may not be applicable to the growing mandible. 5. Understand the etiology and epidemiology of pediatric mandibular fractures. 6. Understand the reasons for conservative (closed) versus aggressive (open) treatment of mandibular injury. Fractures of the pediatric mandible are complicated by the anatomic complexity of the developing mandible, particularly by the presence of tooth buds and the eruption of deciduous and permanent teeth. Traditional methods of fracture reduction and fixation employed in adults have little applicability in the pediatric population. The authors describe the surgical techniques that have been used at their institution and those that can be used safely in the pediatric setting. In most cases, "conservative" management is the preferred option, especially in the treatment of condylar fractures. In cases requiring surgical intervention, interdental wiring, drop wires in combination with circummandibular wires, and acrylic splints are suited well to specific phases of dental maturation. Open reduction and internal fixation using monocortical screws and microplates or resorbable plates and screws are acceptable techniques in the pediatric patient, but they require special safeguards. Algorithms are presented to simplify management of these complicated injuries.

Health Instruction Packages: Permanent Teeth, Dental Deposits, and Dental Instruments. Dientes Permanentes, Depositos Dentales y Instrumentos Dentales.

ERIC Educational Resources Information Center

Lind, Patricia; Germano, Catherine

These five learning modules use text interspersed with illustrations and reinforcement exercises to instruct dental aide and dental hygiene students about jaw bones and gums, dental deposits, and dental instruments. The first four modules were prepared by Patricia Lind in both Spanish and English. "The Gum and Bone of Permanent Teeth"…

The failures of root canal preparation with hand ProTaper

PubMed Central

Bătăiosu, Marilena; Diaconu, Oana; Moraru, Iren; Dăguci, C.; Ţuculină, Mihaela; Dăguci, Luminiţa; Gheorghiţă, Lelia

2012-01-01

The failures of root canal preparation are due to some anatomical deviation (canal in “C” or “S”) and some technique errors. The technique errors are usually present in canal root cleansing and shaping stage and are the result of endodontic treatment objectives deviation. Objectives: Our study was made on technique errors while preparing the canal roots with hand ProTaper. Methodology: Our study was made “in vitro” on 84 extracted teeth (molars, premolars, incisors and canines). The canal root of these teeth were cleansed and shaped with hand ProTaper by crown-down technique and canal irrigation with NaOCl(2,5%). The dental preparation control was made by X-ray. Results: During canal root preparation some failures were observed like: canal root overinstrumentation, zipping and stripping phenomenon, discarded and/or fractured instruments. Conclusions: Hand ProTaper represents a revolutionary progress of endodontic treatment, but a deviation from accepted rules of canal root instrumentation can lead to failures of endodontic treatment. PMID:24778848

The effect of luting media on the fracture resistance of a flame sprayed all-ceramic crown.

PubMed

Casson, A M; Glyn Jones, J C; Youngson, C C; Wood, D J

2001-11-01

This in vitro study investigated the effect of selected luting media on the fracture resistance of a flame-sprayed all-ceramic crown. Three groups of 10 human upper premolar teeth were prepared for crowning using a standardised technique. Flame sprayed crowns were fabricated and cemented onto the preparations using zinc phosphate (ZPC), glass polyalkenoate (GPC) or composite luting cement (CLC). During crown seating, a pressure perfusion system simulated pulpal fluid outflow equivalent to 300mm of H2O. Compressive fracture resistance was determined for each group using a Universal Testing Machine with a crosshead speed of 1mm min(-1). A group of unrestored teeth acted as a control. The fracture resistance of the groups ranked as follows: ZPC>CLC>GPC=unrestored teeth. The difference between the fracture resistance of ZPC and CLC groups and the control group was statistically significant. The mode of fracture between the luted crowns and natural crowns was markedly different. When tested in compression, a new, flame-sprayed all-ceramic crown, when luted in place using ZPC, GPC or CLC, could produce strengths comparable to or greater than natural unrestored teeth. The luting agent used significantly affected the recorded fracture loads.

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

PubMed

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

2011-05-01

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

Study of surface topography, roughness, and microleakage after dental preparation with different instrumentation.

PubMed

Solá-Ruiz, Ma Fernanda; Faus-Matoses, Ignacio; Del Rio Highsmith, Jamie; Fons-Font, Antonio

2014-01-01

The purpose of this study was to compare the differences in surface characteristics and roughness of teeth finished for porcelain veneer laminates using different instrumentation and to assess their influence on microleakage. Fifty-six extracted human maxillary central incisors were divided randomly into two groups: Group HsR teeth were finished with a high-speed handpiece with diamond burs; group SO teeth were finished with a sonic oscillating diamond instrument. Porcelain veneers were bonded to 24 teeth in each group. Microleakage was measured in the cervical area. Four remaining teeth in each group were examined using confocal laser-scanning microscopy and scanning electron microscopy. Oscillating instruments produced a rougher dentinal surface (Ra values; P = .029) than those finished with high-speed rotary technology. There is less microleakage when bonded restoration edges are situated over dentin that has been finished with sonic oscillating instrumentation (P = .006).

Functional and esthetic rehabilitation of a child with amelogenesis imperfecta: a case report.

PubMed

Moura, Carmem Dolores Vilarinho Soares de; Pontes, Alessandra Silva; Lopes, Teresinha Soares Pereira; Moura, Lúcia Fátima Almeida de Deus; Lima, Marina Deus Moura de

2017-01-01

Amelogenesis imperfecta (AI) is a tooth disorder characterized by the abnormal development of the enamel in response to mutations in the genes involved in amelogenesis. The objective of this article is to present the clinical case of a child with AI in the primary dentition phase. A 4-year-old boy was presented to a clinic by his mother, who complained that her son's smile esthetics were compromised by "weak and yellow teeth." All the teeth showed yellowish discoloration as well as crumbling or missing enamel. Due to the absence of carious lesions and the presence of normal pulp in the teeth, it was decided to restore the dentition with indirect crowns of ceramic-optimized polymer, also known as ceromer. No preparations were performed on the teeth. For this patient, indirect ceromer restorations presented a good treatment option for the rehabilitation of primary teeth affected by AI.

An audit of the use of intra-septal local anaesthesia in a dental practice in the South of England.

PubMed

Doman, Stephen M

2011-04-01

The aim of this audit was to evaluate the efficacy, when used by the author, of the intra-septal local anaesthetic technique for cavity preparation in mandibular molar and premolar teeth. One hundred and thirteen consecutive patients who required local anaesthesia (LA) for cavity preparation in lower molar and premolar teeth in a general dental practice took part in the audit sample. Articaine 4%, with 1:100,000 adrenaline (epinephrine), was administered using the intra-septal technique. Visual analogue scales (VAS) were used to record pain experienced on injection and the quality of anaesthesia obtained. Any side-effects reported were recorded. The standards set were that at least 70% should find the administration of the LA pain-free and that at least 80% should experience no pain during cavity preparation. Sixty-nine (62%) patients reported the injection technique to be completely pain-free and a further 23 (20%) reported very minor pain on injection. Eighty (71%) patients reported pain-free treatment and 18 (16%) experienced very minor pain during treatment. No side-effects were reported. Patients aged under 40 years and those who had cavities prepared in first premolar teeth appeared more likely to experience pain during cavity preparation. The intra-septal injection technique requires no specialist equipment, is easily administered, rapid in onset and provides a level of anaesthesia equivalent to that produced by an inferior dental nerve block and with fewer side-effects. The injection is relatively painless to administer.

Color-Matching and Blending-Effect of Universal Shade Bulk-Fill-Resin-Composite in Resin-Composite-Models and Natural Teeth.

PubMed

Abdelraouf, Rasha M; Habib, Nour A

2016-01-01

Objectives . To assess visually color-matching and blending-effect (BE) of a universal shade bulk-fill-resin-composite placed in resin-composite-models with different shades and cavity sizes and in natural teeth (extracted and patients' teeth). Materials and Methods . Resin-composite-discs (10 mm × 1 mm) were prepared of universal shade composite and resin-composite of shades: A1, A2, A3, A3.5, and A4. Spectrophotometric-color-measurement was performed to calculate color-difference (Δ E ) between the universal shade and shaded-resin-composites discs and determine their translucency-parameter (TP). Visual assessment was performed by seven normal-color-vision-observers to determine the color-matching between the universal shade and each shade, under Illuminant D65. Color-matching visual scoring (VS) values were expressed numerically (1-5): 1: mismatch/totally unacceptable, 2: Poor-Match/hardly acceptable, 3: Good-Match/acceptable, 4: Close-Match/small-difference, and 5: Exact-Match/no-color-difference. Occlusal cavities of different sizes were prepared in teeth-like resin-composite-models with shades A1, A2, A3, A3.5, and A4. The cavities were filled by the universal shade composite. The same scale was used to score color-matching between the fillings and composite-models. BE was calculated as difference in mean-visual-scores in models and that of discs. Extracted teeth with two different class I-cavity sizes as well as ten patients' lower posterior molars with occlusal caries were prepared, filled by universal shade composite, and assessed similarly. Results . In models, the universal shade composite showed close matching in the different cavity sizes and surrounding shades (4 ≤ VS < 5) (BE = 0.6-2.9 in small cavities and 0.5-2.8 in large cavities). In extracted teeth, there was good-to-close color-matching (VS = 3.7-4.4 in small cavities, BE = 2.5-3.2) (VS = 3-3.5, BE = 1.8-2.3 in large cavities). In patients' molars, the universal shade composite showed good-matching (VS = 3-3.3, BE = -0.9-2.1). Conclusions . Color-matching of universal shade resin-composite was satisfactory rather than perfect in patients' teeth.

Technical quality of root canal treatment of posterior teeth after rotary or hand preparation by fifth year undergraduate students, The University of Jordan.

PubMed

Abu-Tahun, Ibrahim; Al-Rabab'ah, Mohammad A; Hammad, Mohammad; Khraisat, Ameen

2014-12-01

The aim of this study was to investigate the technical quality of root canal treatment provided by the undergraduate students as their first experience in molar endodontics using nickel-titanium (NiTi) files in a crown-down approach compared with stainless steel standard technique. This study was carried out by the fifth year undergraduate students attending peer review sessions as a part of their training programme, using two different questionnaires to assess the overall technical quality and potential problems regarding endodontic complications after root canal preparation with these two techniques. The overall results indicated a statistically significant difference in the performance of the two instrument techniques in difficult cases showing better performance of the NiTi system and mean rotary preparation time (P < 0.001). Under the conditions of this study, novice dental students, using NiTi ProTaper rotary files, were able to prepare root canals faster with more preparation accuracy compared with canals of same teeth prepared with hand instruments. © 2014 Australian Society of Endodontology.

Effect of Different Ceramic Crown Preparations on Tooth Structure Loss: An In Vitro Study

NASA Astrophysics Data System (ADS)

Ebrahimpour, Ashkan

Objective: To quantify and compare the amount of tooth-structure reduction following the full-coverage preparations for crown materials of porcelain-fused-to-metal, lithium disilicate glass-ceramic and yttria-stabilized tetragonal zirconia polycrystalline for three tooth morphologies. Methods: Groups of resin teeth of different morphologies were individually weighed to high precision, then prepared following the preparation guidelines. The teeth were re-weighed after preparation and the amount of structural reduction was calculated. Statistical analyses were performed to find out if there was a significant difference among the groups. Results: Amount of tooth reduction for zirconia crown preparations was the lowest and statistically different compared with the other two materials. No statistical significance was found between the amount of reduction for porcelain-fused-to-metal and lithium disilicate glass-ceramic crowns. Conclusion: Within the limitations of this study, more tooth structure can be saved when utilizing zirconia full-coverage restorations compared with lithium disilicate glass-ceramic and porcelain-fused-to-metal crowns in maxillary central incisors, first premolars and first molars.

Influence of growth hormone therapy on selected dental and skeletal system parameters.

PubMed

Partyka, Małgorzata; Chałas, Renata; Dunin-Wilczyńska, Izabella; Drohomyretska, Myroslava; Klatka, Maria

2018-03-14

Growth hormone deficiency (GHD) is one of the main indications for growth hormone therapy. One characteristic of this disease is bone age delay in relation to the chronological age. Pituitary dysfunction negatively affects the growth and development of the jaws and teeth of the child. The secretion of endocrine glands regulates growth, development, and gender differentiation. It also controls the growth of bones and teeth, regulates metabolism of calcium and phosphate, proteins, lipids and carbohydrates. The primary role in the endocrine system is played by the pituitary gland which is responsible for the production of somatotropin [1]. Dysfunction of the pituitary gland has a negative effect on the growth and development of long bones in the body, and may have an adverse effect on the development of maxilla, mandible and dentition of a child. There is some information in the literature that dental age is delayed in short stature children; the replacement of deciduous teeth by permanent teeth is also delayed, and newly erupted permanent teeth often require orthodontic treatment. Applying hormonal therapy positively affects the process of replacement of dentition [2, 3, 4, 5, 6]. The aim of the study was to assess bone and dental age, as well as analyze the state of dentition in children diagnosed with GH deficiency treated with growth hormone, depending on the duration of treatment. The study material consisted of 110 children (27 males, 83 females), hospitalized for somatotropin hypopituitarism in the Department of Paediatric Endocrinology and Diabetology at the Medical University of Lublin, Poland. The mean birth age was 13 years (156 months) with a standard deviation of 2 years and 6 months (30 months). 47 children (43%) started treatment with the growth hormone (group starting treatment) and 63 children (57%) whose treatment was started 2-3 years previously (group in the course of treatment). The control group consisted of 41 generally healthy children (15males, 25 females) with ENT problems, such as hypoacusis and a condition after nasal injury, hospitalized in the Department of Paediatric Otolaryngology at the Medical University of Lublin, Poland. The mean age was 11 years and 5 months (137 months) with standard deviation of 2 years and 5 months (29 months). Informed consent was obtained from the parents. The study was approved by the Bioethical Committee at the Medical University of Lublin (Resolution No. KE-0254 /216 /2012).

Evaluation of the Self-Adjusting File system (SAF) for the instrumentation of primary molar root canals: a micro-computed tomographic study.

PubMed

Kaya, E; Elbay, M; Yiğit, D

2017-06-01

The Self-Adjusting File (SAF) system has been recommended for use in permanent teeth since it offers more conservative and effective root-canal preparation when compared to traditional rotary systems. However, no study had evaluated the usage of SAF in primary teeth. The aim of this study was to evaluate and compare the use of SAF, K file (manual instrumentation) and Profile (traditional rotary instrumentation) systems for primary-tooth root-canal preparation in terms of instrumentation time and amounts of dentin removed using micro-computed tomography (μCT) technology. Study Design: The study was conducted with 60 human primary mandibular second molar teeth divided into 3 groups according to instrumentation technique: Group I: SAF (n=20); Group II: K file (n=20); Group III; Profile (n=20). Teeth were embedded in acrylic blocks and scanned with a μCT scanner prior to instrumentation. All distal root canals were prepared up to size 30 for K file,.04/30 for Profile and 2 mm thickness, size 25 for SAF; instrumentation time was recorded for each tooth, and a second μCT scan was performed after instrumentation was complete. Amounts of dentin removed were measured using the three-dimensional images by calculating the difference in root-canal volume before and after preparation. Data was statistically analysed using the Kolmogorov-Smirnov and Kruskal-Wallis tests. Manual instrumentation (K file) resulted in significantly more dentin removal when compared to rotary instrumentation (Profile and SAF), while the SAF system generated significantly less dentin removal than both manual instrumentation (K file) and traditional rotary instrumentation (Profile) (p<.05). Instrumentation time was significantly greater with manual instrumentation when compared to rotary instrumentation (p<.05), whereas instrumentation time did not differ significantly between the Profile and SAF systems. Within the experimental conditions of the present study, the SAF seems as a useful system for root-canal instrumentation in primary molars because it removed less dentin than other systems, which is especially important for the relatively thin-walled canals of primary teeth, and because it involves less clinical time, which is particularly important in the treatment of paediatric patients.

Black Stains: a microbiological analysis and a view on familiarity and susceptibility to tooth decay of patients in childhood.

PubMed

Tripodi, D; Martinelli, D; Pasini, M; Giuca, M R; D'Ercole, S

2016-12-01

Assess prevalence, familial predisposition and susceptibility to caries of Black Stains (BS). Evaluate the microbiological composition of BS, saliva and subgingival plaque. Sixty nine subjects with BS (test group) and 120 subjects without BS (control group) were analysed for oral status. For each BS-patient, a BS-deposit, 1 ml of saliva and subgingival plaque were collected and microbiologically analysed. Five deciduous teeth with BS were observed under SEM. This study showed a BS prevalence similar to that of the Mediterranean area and a familiality. The microbiological origin of BS was confirmed by SEM and culture method and the BS flora differ from that of supragingival plaque. Predominance in BS and saliva of Actinomycetes and the low salivary prevalence of S. mutans and L. acidophilus may be related with low caries incidence in BS patients. The high presence of Actinomyces spp can be a causative factor for BS.

Effect of lip bumpers on mandibular arch dimensions.

PubMed

Hashish, Dena Ibrahim; Mostafa, Yehya Ahmed

2009-01-01

The aim of this systematic review was to examine the effects of lip bumper therapy on mandibular arch dimensions. A literature survey of PubMed, EMBASE, Cochrane Central, and Cochrane Database of Systematic Reviews (www.cochrane.org) was conducted from December 1968 to January 2007. Human studies, randomized clinical trials, prospective and retrospective studies, and studies discussing the effect of lip bumpers on the arch and teeth were included. Two reviewers independently selected and extracted the data. Of the 52 studies found in the search, only 1 met the inclusion criteria. The results showed increases in arch dimensions that included an increase in arch length. This was attributed to incisor proclination, distalization, and distal tipping of the molars. There was also an increase in the arch width seen in the intercanine and deciduous intermolar and premolar distances. The long-term stability of the effects of the lip bumper need to be elucidated.

Repair of a pediatric bilateral condylar and symphyseal fracture using a transfacial Steinman pin.

PubMed

Grow, Jacob N; Flores, Roberto L; Tholpady, Sunil S

2014-01-01

The proper management of complex pediatric mandibular fractures remains a topic of debate because of the relatively uncommon presentation of these fractures, combined with concerns related with deciduous teeth, tooth buds, and growth inhibition. In this current study, we present a novel approach to the repair of bilateral condylar fractures with concomitant symphyseal fracture in a 4-year-old girl. Manual closed reduction was first obtained, followed by placement of a transfacial Steinman pin through the angles of the mandible and placement of circummandibular wires. Maxillomandibular fixation remained for 2 weeks and the Steinman pin was removed after 11 weeks. At 3 months of postsurgical follow-up, the patient displayed class I occlusion, facial symmetry, full range of jaw motion, and absence of deviation or pain on full oral excursion. Radiographic findings also revealed complete resolution of the symphyseal fracture with appropriate condylar healing and alignment.

Carica papaya induces in vitro thrombopoietic cytokines secretion by mesenchymal stem cells and haematopoietic cells.

PubMed

Aziz, Jazli; Abu Kassim, Noor Lide; Abu Kasim, Noor Hayaty; Haque, Nazmul; Rahman, Mohammad Tariqur

2015-07-08

Use of Carica papaya leaf extracts, reported to improve thrombocyte counts in dengue patients, demands further analysis on the underlying mechanism of its thrombopoietic cytokines induction In vitro cultures of peripheral blood leukocytes (PBL) and stem cells from human exfoliated deciduous teeth (SHED) were treated with unripe papaya pulp juice (UPJ) to evaluate its potential to induce thrombopoietic cytokines (IL-6 and SCF) RESULTS: In vitro scratch gap closure was significantly faster (p < .05) in SHED culture treated with UPJ. IL-6 concentration was significantly increased (p < .05) in SHED and PBL culture supernatant when treated with UPJ. SCF synthesis in SHED culture was also significantly increased (p < .05) when treated with UPJ CONCLUSION: In vitro upregulated synthesis of IL -6 and SCF both in PBL and SHED reveals the potential mechanism of unripe papaya to induce thrombopoietic cytokines synthesis in cells of hematopoietic and mesenchymal origin.

Demineralization of Enamel in Primary Second Molars Related to Properties of the Enamel

PubMed Central

Sabel, N.; Robertson, A.; Nietzsche, S.; Norén, J. G.

2012-01-01

Enamel structure is of importance in demineralization. Differences in porosity in enamel effect the rate of demineralization, seen between permanent and deciduous teeth. Individual differences have been shown in the mean mineral concentration values in enamel, the role of this in demineralization is not thoroughly investigated. The aim of this study was to study variations of depths of artificial lesions of demineralization and to analyze the depth in relation to variations in the chemical and mineral composition of the enamel. A demineralized lesion was created in second primary molars from 18 individuals. Depths of lesions were then related to individual chemical content of the enamel. Enamel responded to demineralization with different lesion depths and this was correlated to the chemical composition. The carbon content in sound enamel was shown to be higher where lesions developed deeper. The lesion was deeper when the degree of porosity of the enamel was higher. PMID:22629152

[Caries and fluorine: role of water factor, problems and solutions].

PubMed

Rakhmanin, Iu A; Kir'ianova, L F; Mikhaĭlova, R I; Sevost'ianova, E M

2001-01-01

The epidemiological studies of the severity and spread of caries of deciduous and permanent teeth in Moscow schoolchildren (n = > 20,000) aged 7-17 years in relation to the content of fluoride in the drinking water, to the use of fluorine-containing tablets and varnishes have provided evidence for the high efficiency of drinking water fluorination for the primary prevention of caries as compared with other preventive alternatives. Based on sanitary studies, two main lines are now under way in solving the problem connected with low dietary fluoride intake: the introduction of routine water-purifying fluorine generators (based on a new technology of fluorination of limited water volumes for drinking and cooking) and the setting-up of plants manufacturing bottled drinking waters containing the optimum or higher fluorine levels for provision of different population groups, primarily children and pregnant women in particular.

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

Late Cretaceous- Cenozoic history of deciduousness and the terminal Cretaceous event.

USGS Publications Warehouse

Wolfe, J.A.

1987-01-01

Deciduousness in mesic, broad-leaved plants occurred in disturbed, middle-latitude environments during the Late Cretaceous. Only in polar environments in the Late Cretaceous was the deciduous element dominant, although of low diversity. The terminal Cretaceous event resulted in wide-spread selection for plants of deciduous habit and diversification of deciduous taxa, thus leaving a lasting imprint on Northern Hemisphere vegetation. Various environmental factors have played important roles in subsequent diversification of mesic, broad-leaved deciduous taxa and in origination and decline of broad-leaved deciduous forests. Low diversity and rarity of mesic deciduous plants in the post-Cretaceous of the Southern Hemisphere indicate that the inferred 'impact winter' of the terminal Cretaceous event had little effect on Southern Hemisphere vegetation and climate. -Author

Involvement of atypical transcription factor E2F8 in the polyploidization during mouse and human decidualization.

PubMed

Qi, Qian-Rong; Zhao, Xu-Yu; Zuo, Ru-Juan; Wang, Tong-Song; Gu, Xiao-Wei; Liu, Ji-Long; Yang, Zeng-Ming

2015-01-01

Polyploid decidual cells are specifically differentiated cells during mouse uterine decidualization. However, little is known about the regulatory mechanism and physiological significance of polyploidization in pregnancy. Here we report a novel role of E2F8 in the polyploidization of decidual cells in mice. E2F8 is highly expressed in decidual cells and regulated by progesterone through HB-EGF/EGFR/ERK/STAT3 signaling pathway. E2F8 transcriptionally suppresses CDK1, thus triggering the polyploidization of decidual cells. E2F8-mediated polyploidization is a response to stresses which are accompanied by decidualization. Interestingly, polyploidization is not detected during human decidualization with the down-regulation of E2F8, indicating differential expression of E2F8 may lead to the difference of decidual cell polyploidization between mice and humans.

Involvement of atypical transcription factor E2F8 in the polyploidization during mouse and human decidualization

PubMed Central

Qi, Qian-Rong; Zhao, Xu-Yu; Zuo, Ru-Juan; Wang, Tong-Song; Gu, Xiao-Wei; Liu, Ji-Long; Yang, Zeng-Ming

2015-01-01

Polyploid decidual cells are specifically differentiated cells during mouse uterine decidualization. However, little is known about the regulatory mechanism and physiological significance of polyploidization in pregnancy. Here we report a novel role of E2F8 in the polyploidization of decidual cells in mice. E2F8 is highly expressed in decidual cells and regulated by progesterone through HB-EGF/EGFR/ERK/STAT3 signaling pathway. E2F8 transcriptionally suppresses CDK1, thus triggering the polyploidization of decidual cells. E2F8-mediated polyploidization is a response to stresses which are accompanied by decidualization. Interestingly, polyploidization is not detected during human decidualization with the down-regulation of E2F8, indicating differential expression of E2F8 may lead to the difference of decidual cell polyploidization between mice and humans. PMID:25892397

Age estimation from dental cementum incremental lines and periodontal disease.

PubMed

Dias, P E M; Beaini, T L; Melani, R F H

2010-12-01

Age estimation by counting incremental lines in cementum added to the average age of tooth eruption is considered an accurate method by some authors, while others reject it stating weak correlation between estimated and actual age. The aim of this study was to evaluate this technique and check the influence of periodontal disease on age estimates by analyzing both the number of cementum lines and the correlation between cementum thickness and actual age on freshly extracted teeth. Thirty one undecalcified ground cross sections of approximately 30 µm, from 25 teeth were prepared, observed, photographed and measured. Images were enhanced by software and counts were made by one observer, and the results compared with two control-observers. There was moderate correlation ((r)=0.58) for the entire sample, with mean error of 9.7 years. For teeth with periodontal pathologies, correlation was 0.03 with a mean error of 22.6 years. For teeth without periodontal pathologies, correlation was 0.74 with mean error of 1.6 years. There was correlation of 0.69 between cementum thickness and known age for the entire sample, 0.25 for teeth with periodontal problems and 0.75 for teeth without periodontal pathologies. The technique was reliable for periodontally sound teeth, but not for periodontally diseased teeth.

CO2 Laser and Topical Fluoride Therapy in the Control of Caries Lesions on Demineralized Primary Enamel

PubMed Central

Valério, R. A.; Saraiva, M. C. P.; Corona, S. A. M.

2015-01-01

This study evaluated the effect of CO2 laser irradiation and topical fluoride therapy in the control of caries progression on primary teeth enamel. 30 fragments (3 × 3 × 2 mm) from primary canines were submitted to an initial cariogenic challenge that consisted of immersion on demineralizing solution for 3 hours and remineralizing solution for 21 hours for 5 days. Fragments were randomly assigned into three groups (n = 10): L: CO2 laser (λ = 10.6 μm), APF: 1.23% acidulated phosphate fluoride, and C: no treatment (control). CO2 laser was applied with 0.5 W power and 0.44 J/cm2 energy density. Fluoride application was performed with 0.1 g for 1 minute. Cariogenic challenge was conducted for 5 days following protocol previously described. Subsurface Knoop microhardness was measured at 30 μm from the edge. Obtained data were subjected to analysis the variance (ANOVA) and Duncan test with significance of 5%. It was found that the L group showed greater control of deciduous enamel demineralization and were similar to those of APF group, while being statistically different from C group (P ≤ 0.05) that showed the lowest microhardness values. It was concluded that CO2 laser can be an additional resource in caries control progression on primary teeth enamel. PMID:25874248

Sensitivity of leaf size and shape to climate: Global patterns and paleoclimatic applications

USGS Publications Warehouse

Peppe, D.J.; Royer, D.L.; Cariglino, B.; Oliver, S.Y.; Newman, S.; Leight, E.; Enikolopov, G.; Fernandez-Burgos, M.; Herrera, F.; Adams, J.M.; Correa, E.; Currano, E.D.; Erickson, J.M.; Hinojosa, L.F.; Hoganson, J.W.; Iglesias, A.; Jaramillo, C.A.; Johnson, K.R.; Jordan, G.J.; Kraft, N.J.B.; Lovelock, E.C.; Lusk, C.H.; Niinemets, U.; Penuelas, J.; Rapson, G.; Wing, S.L.; Wright, I.J.

2011-01-01

Paleobotanists have long used models based on leaf size and shape to reconstruct paleoclimate. However, most models incorporate a single variable or use traits that are not physiologically or functionally linked to climate, limiting their predictive power. Further, they often underestimate paleotemperature relative to other proxies. Here we quantify leaf-climate correlations from 92 globally distributed, climatically diverse sites, and explore potential confounding factors. Multiple linear regression models for mean annual temperature (MAT) and mean annual precipitation (MAP) are developed and applied to nine well-studied fossil floras. We find that leaves in cold climates typically have larger, more numerous teeth, and are more highly dissected. Leaf habit (deciduous vs evergreen), local water availability, and phylogenetic history all affect these relationships. Leaves in wet climates are larger and have fewer, smaller teeth. Our multivariate MAT and MAP models offer moderate improvements in precision over univariate approaches (??4.0 vs 4.8??C for MAT) and strong improvements in accuracy. For example, our provisional MAT estimates for most North American fossil floras are considerably warmer and in better agreement with independent paleoclimate evidence. Our study demonstrates that the inclusion of additional leaf traits that are functionally linked to climate improves paleoclimate reconstructions. This work also illustrates the need for better understanding of the impact of phylogeny and leaf habit on leaf-climate relationships. ?? 2011 The Authors. New Phytologist ?? 2011 New Phytologist Trust.

Rotary endodontics in primary teeth – A review

PubMed Central

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

2015-01-01

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

Rotary endodontics in primary teeth - A review.

PubMed

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

2016-01-01

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

Overlay removable denture for treatment of worn teeth.

PubMed

Beyth, Nurit; Tamari, Israel; Buller Sharon, Anat

2014-01-01

Rehabilitation of partially edentulous patients with excessively worn dentitions can be challenging. Factors including medical history as well as the cost of the treatment and patient wishes for simpler approaches must be considered. This manuscript describes the use of an overlay partial denture to treat patients with excessive wear of the maxillary teeth. We describe a technique to restore severely worn teeth using heat-cured acrylic as part of a partial or full denture. Minimal preparations of the teeth are required, and the restoration provides protection from further wear, and stabilizes the occlusion. This solution was functionally and esthetically suitable to the patients. The technique can be used in medically complex patients where extractions are contraindicated, such as post radiation therapy or bisphosphonate treatment. © 2014 Special Care Dentistry Association and Wiley Periodicals, Inc.

Incidence of apical root cracks and apical dentinal detachments after canal preparation with hand and rotary files at different instrumentation lengths.

PubMed

Liu, Rui; Kaiwar, Anjali; Shemesh, Hagay; Wesselink, Paul R; Hou, Benxiang; Wu, Min-Kai

2013-01-01

The aim of this study was to compare the incidence of apical root cracks and dentinal detachments after canal preparation with hand and rotary files at different instrumentation lengths. Two hundred forty mandibular incisors were mounted in resin blocks with simulated periodontal ligaments, and the apex was exposed. The root canals were instrumented with rotary and hand files, namely K3, ProTaper, and nickel-titanium Flex K files to the major apical foramen (AF), short AF, or beyond AF. Digital images of the apical surface of every tooth were taken during the apical enlargement at each file change. Development of dentinal defects was determined by comparing these images with the baseline image. Multinomial logistic regression test was performed to identify influencing factors. Apical crack developed in 1 of 80 teeth (1.3%) with hand files and 31 of 160 teeth (19.4%) with rotary files. Apical dentinal detachment developed in 2 of 80 teeth (2.5%) with hand files and 35 of 160 teeth (21.9%) with rotary files. Instrumentation with rotary files terminated 2 mm short of AF and did not cause any cracks. Significantly less cracks and detachments occurred when instrumentation with rotary files was terminated short of AF, as compared with that terminated at or beyond AF (P < .05). The AF deviated from the anatomic apex in 128 of 240 teeth (53%). Significantly more apical dentinal detachments appeared in teeth with a deviated AF (P = .033). Rotary instruments caused more dentinal defects than hand instruments; instrumentation short of AF reduced the risk of dentinal defects. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The success rate of bupivacaine and lidocaine as anesthetic agents in inferior alveolar nerve block in teeth with irreversible pulpitis without spontaneous pain.

PubMed

Parirokh, Masoud; Yosefi, Mohammad Hosein; Nakhaee, Nouzar; Abbott, Paul V; Manochehrifar, Hamed

2015-05-01

Achieving adequate anesthesia with inferior alveolar nerve blocks (IANB) is of great importance during dental procedures. The aim of the present study was to assess the success rate of two anesthetic agents (bupivacaine and lidocaine) for IANB when treating teeth with irreversible pulpitis. Sixty volunteer male and female patients who required root canal treatment of a mandibular molar due to caries participated in the present study. The inclusion criteria included prolonged pain to thermal stimulus but no spontaneous pain. The patients were randomly allocated to receive either 2% lidocaine with 1:80,000 epinephrine or 0.5% bupivacaine with 1:200,000 epinephrine as an IANB injection. The sensitivity of the teeth to a cold test as well as the amount of pain during access cavity preparation and root canal instrumentation were recorded. Results were statistically analyzed with the Chi-Square and Fischer's exact tests. At the final step, fifty-nine patients were included in the study. The success rate for bupivacaine and lidocaine groups were 20.0% and 24.1%, respectively. There was no significant difference between the two groups at any stage of the treatment procedure. There was no difference in success rates of anesthesia when bupivacaine and lidocaine were used for IANB injections to treat mandibular molar teeth with irreversible pulpitis. Neither agent was able to completely anesthetize the teeth effectively. Therefore, practitioners should be prepared to administer supplemental anesthesia to overcome pain during root canal treatment.

Anti-Inflammatory and Regenerative Effects of Albanian Propolis in Experimental Vital Amputations.

PubMed

Meto, Aida; Meto, Agron; Bimbari, Bora; Shytaj, Kastriot; Özcan, Mutlu

2016-09-01

This study evaluated the effects of Albanian propolis on the inflamed pulpal tissue after pulpotomy in piglets. In five piglets, two teeth each were infected using special pathogenic microbial flora that was prepared in advance in order to cause inflammation of the pulp. Pulpotomy was performed in the maxillary and mandibular central and lateral incisors. Microbial flora pathogenesis prepared from the section of infected teeth, containing Staphylococcus aureus, Streptococcus viridans, Enterococcus faecalis, Staphylococcus albus and mixed flora were used to cause artificial pulpitis. The first group consisted of piglets with the teeth having pulpal inflammation and regeneration without medication served as the control group. In the second group, the teeth were treated with pure propolis after vital amputation. In the 3rd, 4th and 5th groups, the teeth were treated after vital amputation with the compounds of ZnO+10%, ZnO+20% propolis in ethanol, and with the paste composed of Ca(OH) +30% oily propolis, respectively. In half of the teeth, propolis based pastes were applied on the pulp and entries of the cavities were isolated with glass ionomer cement while the other half did not receive this treatment and acted as the control. The cavity entries were obturated with chemically polymerized resin composite. Inflammatory response, dominated by polymorphonuclear cells, was observed in the dental pulpal tissue of all the teeth that were not treated with propolis-based paste. Radiography and histopathology analyses were performed to survey the infected pulp tissue treated with propolis up to 3 months. Data were analyzed using Mann-Whitney U test (a=0.05). After vital amputation of the pulp, application of Albanian propolis showed significantly higher anti-inflammatory and regenerative effect creating dentin barrier after 3 months of treatment compared to control group (p⟨0.05). These results were more expressed in the group containing 20% propolis in ethanol+ZnO. Copyright© 2016 Dennis Barber Ltd.

Fracture resistance of endodontically treated teeth restored with Zirconia filler containing composite core material and fiber posts.

PubMed

Jeaidi, Zaid Al

2016-01-01

To assess the fracture resistance of endodontically treated teeth with a novel Zirconia (Zr) nano-particle filler containing bulk fill resin composite. Forty-five freshly extracted maxillary central incisors were endodontically treated using conventional step back preparation and warm lateral condensation filling. Post space preparation was performed using drills compatible for fiber posts (Rely X Fiber Post) on all teeth (n=45), and posts were cemented using self etch resin cement (Rely X Unicem). Samples were equally divided into three groups (n=15) based on the type of core materials, ZirconCore (ZC) MulticCore Flow (MC) and Luxacore Dual (LC). All specimens were mounted in acrylic resin and loads were applied (Universal testing machine) at 130° to the long axis of teeth, at a crosshead speed of 0.5 mm/min until failure. The loads and the site at which the failures occurred were recorded. Data obtained was tabulated and analyzed using a statistical program. The means and standard deviations were compared using ANOVA and Multiple comparisons test. The lowest and highest failure loads were shown by groups LC (18.741±3.02) and MC (25.16±3.30) respectively. Group LC (18.741±3.02) showed significantly lower failure loads compared to groups ZC (23.02±4.21) and MC (25.16±3.30) (p<0.01). However groups ZC (23.02±4.21) and MC (25.16±3.30) showed comparable failure loads (p=0.23). Fracture resistance of endodontically treated teeth restored with Zr filler containing bulk fill composite cores was comparable to teeth restored with conventional Zr free bulk fill composites. Zr filled bulk fill composites are recommended for restoration of endodontically treated teeth as they show comparable fracture resistance to conventional composite materials with less catastrophic failures.

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

PubMed

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

2007-12-01

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

Evaluation of Root Canal Preparation Using Rotary System and Hand Instruments Assessed by Micro-Computed Tomography

PubMed Central

Stavileci, Miranda; Hoxha, Veton; Görduysus, Ömer; Tatar, Ilkan; Laperre, Kjell; Hostens, Jeroen; Küçükkaya, Selen; Muhaxheri, Edmond

2015-01-01

Background Complete mechanical preparation of the root canal system is rarely achieved. Therefore, the purpose of this study was to evaluate and compare the root canal shaping efficacy of ProTaper rotary files and standard stainless steel K-files using micro-computed tomography. Material/Methods Sixty extracted upper second premolars were selected and divided into 2 groups of 30 teeth each. Before preparation, all samples were scanned by micro-computed tomography. Thirty teeth were prepared with the ProTaper system and the other 30 with stainless steel files. After preparation, the untouched surface and root canal straightening were evaluated with micro-computed tomography. The percentage of untouched root canal surface was calculated in the coronal, middle, and apical parts of the canal. We also calculated straightening of the canal after root canal preparation. Results from the 2 groups were statistically compared using the Minitab statistical package. Results ProTaper rotary files left less untouched root canal surface compared with manual preparation in coronal, middle, and apical sector (p<0.001). Similarly, there was a statistically significant difference in root canal straightening after preparation between the techniques (p<0.001). Conclusions Neither manual nor rotary techniques completely prepared the root canal, and both techniques caused slight straightening of the root canal. PMID:26092929

Evaluation of Root Canal Preparation Using Rotary System and Hand Instruments Assessed by Micro-Computed Tomography.

PubMed

Stavileci, Miranda; Hoxha, Veton; Görduysus, Ömer; Tatar, Ilkan; Laperre, Kjell; Hostens, Jeroen; Küçükkaya, Selen; Muhaxheri, Edmond

2015-06-20

Complete mechanical preparation of the root canal system is rarely achieved. Therefore, the purpose of this study was to evaluate and compare the root canal shaping efficacy of ProTaper rotary files and standard stainless steel K-files using micro-computed tomography. Sixty extracted upper second premolars were selected and divided into 2 groups of 30 teeth each. Before preparation, all samples were scanned by micro-computed tomography. Thirty teeth were prepared with the ProTaper system and the other 30 with stainless steel files. After preparation, the untouched surface and root canal straightening were evaluated with micro-computed tomography. The percentage of untouched root canal surface was calculated in the coronal, middle, and apical parts of the canal. We also calculated straightening of the canal after root canal preparation. Results from the 2 groups were statistically compared using the Minitab statistical package. ProTaper rotary files left less untouched root canal surface compared with manual preparation in coronal, middle, and apical sector (p<0.001). Similarly, there was a statistically significant difference in root canal straightening after preparation between the techniques (p<0.001). Neither manual nor rotary techniques completely prepared the root canal, and both techniques caused slight straightening of the root canal.

On vegetation mapping in Alaska using LANDSAT imagery with primary concerns for method and purpose in satellite image-based vegetation and land-use mapping and the visual interpretation of imagery in photographic format

NASA Technical Reports Server (NTRS)

Anderson, J. H. (Principal Investigator)

1976-01-01

The author has identified the following significant results. A simulated color infrared LANDSAT image covering the western Seward Peninsula was used for identifying and mapping vegetation by direct visual examination. The 1:1,083,400 scale print used was prepared by a color additive process using positive transparencies from MSS bands 4, 5, and 7. Seven color classes were recognized. A vegetation map of 3200 sq km area just west of Fairbanks, Alaska was made. Five colors were recognized on the image and identified to vegetation types roughly equivalent to formations in the UNESCO classification: orange - broadleaf deciduous forest; gray - needleleaf evergreen forest; light violet - subarctic alpine tundra vegetation; violet - broadleaf deciduous shrub thicket; and dull violet - bog vegetation.

An In Vivo Evaluation of the Fit of Zirconium-Oxide Based, Ceramic Single Crowns with Vertical and Horizontal Finish Line Preparations.

PubMed

Vigolo, Paolo; Mutinelli, Sabrina; Biscaro, Leonello; Stellini, Edoardo

2015-12-01

Different types of tooth preparations influence the marginal precision of zirconium-oxide based ceramic single crowns. In this in vivo study, the marginal fits of zirconium-oxide based ceramic single crowns with vertical and horizontal finish lines were compared. Forty-six teeth were chosen in eight patients indicated for extraction for implant placement. CAD/CAM technology was used for the production of 46 zirconium-oxide-based ceramic single crowns: 23 teeth were prepared with vertical finishing lines, 23 with horizontal finishing lines. One operator accomplished all clinical procedures. The zirconia crowns were cemented with glass ionomer cement. The teeth were extracted 1 month later. Marginal gaps along vertical planes were measured for each crown, using a total of four landmarks for each tooth by means of a microscope at 50× magnification. On conclusion of microscopic assessment, ESEM evaluation was completed on all specimens. The comparison of the gap between the two types of preparation was performed with a nonparametric test (two-sample Wilcoxon rank-sum test) with a level of significance fixed at p < 0.05. All data were analyzed with STATA12. In the group with horizontal finish line preparations, the median value of the gap was 35.45 μm (Iqr, 0.33); for the vertical finish line group, the median value of the gap was 35.44 μm (Iqr, 0.40). The difference between the two groups was not statistically significant (two-sample Wilcoxon rank-sum test, p = 0.0872). Within the limitations of this study, the gaps of the zirconium-oxide-based ceramic CAD/CAM crowns with vertical and horizontal finish line preparations were not different. © 2015 by the American College of Prosthodontists.

Pulpal blood flow recorded from human premolar teeth with a laser Doppler flow meter using either red or infrared light.

PubMed

Kijsamanmith, Kanittha; Timpawat, Siriporn; Vongsavan, Noppakun; Matthews, Bruce

2011-07-01

To compare red (635 nm) and infrared (780 nm) light for recording pulpal blood flow from human premolar teeth. Recordings were made from 11 healthy teeth in 9 subjects (aged 16-30 years) using a laser Doppler flow meter (Periflux 4001) equipped with both red and infrared lasers. Average blood flow signals were obtained with both light sources alternately from each tooth under five conditions: intact tooth without opaque rubber dam, intact tooth with dam, after injecting local anaesthetic (3% Mepivacaine) (LA) over the apex of the tooth and cavity preparation to almost expose the pulp, after removal and replacement of the pulp, and with the root canal empty. With infrared light, the dam significantly decreased the mean blood flow by 80%. Injecting LA and cavity preparation had no significant effect. Removal and replacement of the pulp reduced the mean blood flow by 58%. There was no further change when the pulp was removed. With red light, the dam reduced the signal from intact teeth by 60%. Injecting LA and cavity preparation had no significant effect. The signal fell by 67% after pulp removal and replacement and did not change significantly when the pulp was removed. Opaque rubber dam minimises the contribution of non-pulpal tissues to the laser Doppler signal recorded from premolars. Using dam, the pulp contributed about 60% to the blood flow signal with both red and infrared light. The difference between them in this respect was not significant. Copyright © 2010 Elsevier Ltd. All rights reserved.

Dental caries and dental fluorosis among 4-, 6-, 12- and 15-year-old children in kindergartens and public schools in Kuwait.

PubMed

Vigild, M; Skougaard, M; Hadi, R A; al-Zaabi, F; al-Yasseen, I

1996-03-01

The purpose of the present study was 1) to describe the occurrence of dental caries and fluorosis among children in kindergartens and public schools in Kuwait, and determine their need for dental health care, 2) to describe changes in caries prevalence and experience from 1982 to 1993 and 3) to provide a baseline for the evaluation of the preventive oral health programmes starting in Kuwait in 1994. The study population comprised 3,500 4-, 6-, 12- and 15-year-old children in kindergartens and public schools in Kuwait, selected by stratified cluster sampling. Dental caries was scored by surface in accordance with WHO criteria, and dental fluorosis was registered by Dean's index (modified). The mean deft was 4.6 at age 4 years, and 6.2 at age 6; 8 and 11 percent of the decay had been treated by extractions or fillings in the two respective age groups. Among the 6-, 12- and 15-year-old children DMFT was 0.2, 2.6 and 3.6 respectively; 12 and 14 percent of the decayed teeth of 12- and 15-year-old children had been treated. As to the 4- and 6-year-old children, 19 and 9 percent were caries-free in the deciduous teeth, while 86, 21 and 14 percent of the 6-, 12- and 15-year-old children were caries-free in the permanent teeth. Among the 4-year-old children 47 percent had caries in the front teeth. None of the children had severe dental fluorosis, but 6 percent at 12 and 15 years showed mild to moderate, but manifest, dental fluorosis. The survey revealed that caries experience as well as caries prevalence had increased since 1982, although there was a marked increase in the number of filled tooth surfaces in all age cohorts. However, in 1993 the DMFT of 12-year-old children was still well within WHO's global goal for the year 2000, whereas the prevalence of dental caries among 6-year-old was considerably higher than the WHO goal.

[The Bridgelok system for additional retention of bonded prostheses].

PubMed

Maroto García, J; Gutiérrez Molero, F; López Montero, M V

1989-04-01

The partial protesis with metal carving and cemented with composite resin is used frequently as a reversible method in order to substitute teeth, due to the light preparation necessary for the original teeth. Recently, a new system (Bridgelok) with pins has been proposed as safer for this kind of protesis. This paper studies if this new system originates a higher resistance compared to other system without pins.

The orphan nuclear receptor Nur77 regulates decidual prolactin expression in human endometrial stromal cells

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

Jiang, Yue; Hu, Yali; Zhao, Jing

2011-01-14

Research highlights: {yields} Decidually produced PRL plays a key role during pregnancy. {yields} Overexpression of Nur77 increased PRL mRNA expression and enhanced decidual PRL promoter activity. {yields} Knockdown of Nur77 decreased decidual PRL secretion induced by 8-Br-cAMP and MPA. {yields} Nur77 is a novel transcription factor that plays an active role in decidual prolactin expression. -- Abstract: Prolactin (PRL) is synthesized and released by several extrapituitary tissues, including decidualized stromal cells. Despite the important role of decidual PRL during pregnancy, little is understood about the factors involved in the proper regulation of decidual PRL expression. Here we present evidence thatmore » the transcription factor Nur77 plays an active role in decidual prolactin expression in human endometrial stromal cells (hESCs). Nur77 mRNA expression in hESCs was significantly increased after decidualization stimulated by 8-Br-cAMP and medroxyprogesterone acetate (MPA). Adenovirus-mediated overexpression of Nur77 in hESCs markedly increased PRL mRNA expression and enhanced decidual PRL promoter (dPRL/-332Luc) activity in a concentration-dependent manner. Furthermore, knockdown of Nur77 in hESCs significantly decreased decidual PRL promoter activation and substantially attenuated PRL mRNA expression and PRL secretion (P < 0.01) induced by 8-Br-cAMP and MPA. These results demonstrate that Nur77 is a novel transcription factor that contributes significantly to the regulation of prolactin gene expression in human endometrial stromal cells.« less

Thermal effects associated with the Nd/YAG dental laser.

PubMed

von Fraunhofer, J A; Allen, D J

1993-01-01

The heat produced at the dentinal pulpal wall opposite the irradiation site was measured during etching of dental enamel with an Nd:YAG laser in preparation for direct bonding of orthodontic appliances. Forty extracted human teeth were randomly divided into four groups of 10 teeth. Within each group, the buccal surfaces of 5 teeth and the lingual surfaces of the other 5 teeth were laser treated for 12 sec. Irradiation was performed with a commercial Nd:YAG laser at the power settings of 80mJ, 1W, 2W and 3W. Prior to irradiation, an occlusal access preparation was made into the pulp in order to facilitate the placement of a thermocouple for measurement of temperature changes at the dentinal pulpal wall opposite the irradiation site. The thermocouple was held against the dentinal pulpal wall and the resulting temperature changes were recorded. Heating effects at the dentinal pulpal wall on both buccal and lingual surfaces showed an increase in heat as a function of the increase in power output from the laser unit (p < 0.01). The temperatures measured at power levels 1-3W appeared to be of sufficient magnitude to cause at least localized pulpal inflammation and possible irreversible damage to the pulp tissue immediately opposite the site of laser irradiation.

Dental preparation with sonic vs high-speed finishing: analysis of microleakage in bonded veneer restorations.

PubMed

Faus-Matoses, Ignacio; Solá-Ruiz, Fernanda

2014-02-01

To compare marginal microleakage in porcelain veneer restorations following dental finishing using two types of instruments to test the hypothesis that microleakage will be less when teeth are prepared with sonic oscillating burs than when prepared with high-speed rotating burs. Fifty-six extracted human maxillary central incisors were selected and divided randomly into two groups. Group 1 samples underwent dental finishing using high-speed rotating diamond burs, while group 2 used sonic oscillating diamond burs. Buccal chamfer preparation was carried out for both groups. Forty eight of the samples (24 per group) were restored using IPS Empress ceramic veneers. 2% methylene blue was used to evaluate microleakage at the tooth/composite veneer interface. Teeth were sectioned lengthwise into three parts and microleakage was measured at two points - cervical and incisal - on each section. Before bonding, four teeth per group underwent SEM examination. Evaluation of microleakage at the cervical dentin margin showed a value of 10.5% in group 1 and 6.6% in group 2, which was statistically significantly different (p < 0.05). Incisal microleakage was 1.3% for group 1 and 1.2% for group 2, which was not significantly different. SEM revealed different patterns of surface texture in both areas according to the instrument used. Group 1 exhibited parallel horizontal abrasion grooves with a milled effect and thick smear layers; group 2 showed abrasive erosion, discontinuous perpendicular depressions, and thin smear layers. Tooth preparations finished with sonic burs produced significantly less microleakage in the cervical dentin area of bonded veneer restorations. No differences were found in the incisal enamel area.

Esthetic Rehabilitation of Anterior Teeth with Laminates Composite Veneers

PubMed Central

Riva, Giancarlo

2014-01-01

No- or minimal-preparation veneers associated with enamel preservation offer predictable results in esthetic dentistry; indirect additive anterior composite restorations represent a quick, minimally invasive, inexpensive, and repairable option for a smile enhancement treatment plan. Current laboratory techniques associated with a strict clinical protocol satisfy patients' restorative and esthetic needs. The case report presented describes minimal invasive treatment of four upper incisors with laminate nanohybrid resin composite veneers. A step-by-step protocol is proposed for diagnostic evaluation, mock-up fabrication and trial, teeth preparation and impression, and adhesive cementation. The resolution of initial esthetic issues, patient satisfaction, and nice integration of indirect restorations confirmed the success of this anterior dentition rehabilitation. PMID:25013730

A Regional Simulation to Explore Impacts of Resource Use and Constraints

DTIC Science & Technology

2007-03-01

mountaintops. (10) Deciduous Forest - This class is composed of forests, which contain at least 75% deciduous trees in the canopy, deciduous ... trees , pine plantations, and evergreen woodlands. (12) Mixed Forest - This class includes forests with mixed deciduous /coniferous canopies, natural...reflective surfaces. Classification of forested wetlands dominated by deciduous trees is probably more accurate than that in areas with 104

Incisor and molar overjet, arch contraction, and molar relationship in the mixed dentition in repaired complete unilateral cleft lip and palate: A qualitative and quantitative appraisal.

PubMed

Disthaporn, Suteeta; Suri, Sunjay; Ross, Bruce; Tompson, Bryan; Baena, Diogenes; Fisher, David; Lou, Wendy

2017-07-01

To compare the mixed dentition incisor and molar overjet, severity of contraction of the dental arch, and the sagittal molar relationship on the cleft side vs the noncleft side in children with repaired complete unilateral cleft of the lip and palate (UCLP). Orthodontic records taken prior to orthodontic preparation for alveolar bone grafting were screened to select study casts from patients with nonsyndromic repaired complete UCLP who did not have mandibular skeletal or dental asymmetry. The study sample comprised dental casts from 74 children aged 8.9 ± 1 years. Standardized digital photographs were acquired at 1:1 magnification. A coordinate system was developed using digital image-processing software (Photoshop CS4 and Adobe Illustrator). Incisor and molar overjet, Angle's classification, and arch contraction were recorded. Descriptive statistics, paired t-tests, and kappa statistics were used to compare the cleft and noncleft sides. A negative overjet of -1 to -5 mm was often present at the incisors, with greater frequency and magnitude on the cleft side. Class II molar relation was more frequent on the cleft side (61.1%) than on the noncleft side (47.2%). Significantly greater contraction of the cleft side deciduous canine and deciduous first molar was noted, while the difference was very minor at the first permanent molar. Cleft side maxillary arch contraction was most severe in the deciduous canine and first deciduous molar region and progressively less severe in the posterior region of the arch. A greater frequency and severity of negative overjet and Class II molar relationship was seen on the cleft side.

Effect of Temperature and Nutrient Concentration on Survival of Foodborne Pathogens in Deciduous Fruit Processing Environments for Effective Hygiene Management.

PubMed

Duvenage, Stacey; Korsten, Lise

2016-11-01

Temperature and good sanitation practices are important factors for controlling growth of microorganisms. Fresh produce is stored at various temperatures to ensure quality and to prolong shelf life. When foodborne pathogens survive and grow on fresh produce at storage temperatures, then additional control strategies are needed to inactivate these pathogens. The aim of this study was to determine how temperatures associated with deciduous fruit processing and storage facilities (0.5, 4, and 21°C) affect the growth and/or survival of Escherichia coli O157:H7, Listeria monocytogenes , Salmonella enterica subsp. enterica serovar Typhimurium, and Staphylococcus aureus under different nutrient conditions (nutrient rich and nutrient poor) and on simulated contact surfaces (vinyl coupons). Information on the growth and survival of foodborne pathogens at specific deciduous fruit processing and storage temperatures (0.5°C) is not available. All pathogens except E. coli O157:H7 were able to survive on vinyl coupons at all temperatures. L. monocytogenes proliferated under both nutrient conditions independent of temperature. S. aureus was the pathogen least affected by nutrient conditions. The survival of foodborne pathogens on the vinyl coupons, a model system for studying surfaces in fruit preparation and storage environments, indicates the potential for cross-contamination of deciduous fruit products under poor sanitation conditions. Foodborne pathogens that can proliferate and survive at various temperatures under different nutrient conditions could lead to fruit cross-contamination. Temperature mismanagement, which could allow pathogen proliferation in contaminated fruit packing houses and storage environments, is a concern. Therefore, proper hygiene and sanitation practices, removal of possible contaminants, and proper food safety management systems are needed to ensure food safety.

[Distortion and vertical fracture of the root: effect produced by condenser design].

PubMed

Dang, D A; Walton, R E

1990-01-01

The incidence of vertical root fractures and the amount of root distortion created during lateral condensation of gutta-percha with either D11 spreaders or B-finger pluggers were evaluated in vitro. Fifty-five extracted human, single-rooted teeth were instrumented using the step-back flare technique. Ten teeth served as positive controls (obturation to the point of fracture) and five teeth as negative controls (prepared but not obtured). Strain gauges were attached to the root surfaces. In the experimental group, 20 teeth were obturated using a D11 spreader and 20 with a B-finger plugger. Recordings were made of root distortion (expansion) created during obturation. Then, after sectioning the teeth, root surfaces of obturated samples were examined for fractures under the scanning electron microscope. Only the more tapered spreader, the D11, produces vertical root fractures, although very few in number. Also, the D11 spreader caused greater root distortion than did the B-finger plugger.

Effect of zoledronic acid used in the root surface treatment of late replanted teeth: a study in rats.

PubMed

Mori, Graziela Garrido; Janjacomo, Daniela Maria de Mendonça; Nunes, Daniele Clapes; Castilho, Lithiene Ribeiro

2010-01-01

This study evaluated the use of zoledronic acid, a resorption inhibitor, as a medication for root resorption treatment of late replanted teeth. Twenty-four maxillary right central incisors of rats were avulsed and kept dry for 30 min. Then, the teeth were divided into 2 groups. In group I, root surface was treated with 2% sodium fluoride for 20 min; in group II, 10-6M zoledronic acid solution was used for 20 min. All root canals were filled with calcium hydroxide. Next, teeth were replanted in their respective sockets. After 15 and 60 days post-replantation, the animals were killed and the anatomic pieces were obtained and prepared for microscopic and morphometric analyses. The results showed that zoledronic acid was capable of limiting the occurrence of root resorption and preserving cementum resorption. Further research must be performed to confirm the use of zoledronic acid in root surface treatment of late replanted teeth.

miRNA Signature and Dicer Requirement during Human Endometrial Stromal Decidualization In Vitro

PubMed Central

Estella, Carlos; Herrer, Isabel; Moreno-Moya, Juan Manuel; Quiñonero, Alicia; Martínez, Sebastián; Pellicer, Antonio; Simón, Carlos

2012-01-01

Decidualization is a morphological and biochemical transformation of endometrial stromal fibroblast into differentiated decidual cells, which is critical for embryo implantation and pregnancy establishment. The complex regulatory networks have been elucidated at both the transcriptome and the proteome levels, however very little is known about the post-transcriptional regulation of this process. miRNAs regulate multiple physiological pathways and their de-regulation is associated with human disorders including gynaecological conditions such as endometriosis and preeclampsia. In this study we profile the miRNAs expression throughout human endometrial stromal (hESCs) decidualization and analyze the requirement of the miRNA biogenesis enzyme Dicer during this process. A total of 26 miRNAs were upregulated and 17 miRNAs downregulated in decidualized hESCs compared to non-decidualized hESCs. Three miRNAs families, miR-181, miR-183 and miR-200, are down-regulated during the decidualization process. Using miRNAs target prediction algorithms we have identified the potential targets and pathways regulated by these miRNAs. The knockdown of Dicer has a minor effect on hESCs during in vitro decidualization. We have analyzed a battery of decidualization markers such as cell morphology, Prolactin, IGFBP-1, MPIF-1 and TIMP-3 secretion as well as HOXA10, COX2, SP1, C/EBPß and FOXO1 expression in decidualized hESCs with decreased Dicer function. We found decreased levels of HOXA10 and altered intracellular organization of actin filaments in Dicer knockdown decidualized hESCs compared to control. Our results provide the miRNA signature of hESC during the decidualization process in vitro. We also provide the first functional characterization of Dicer during human endometrial decidualization although surprisingly we found that Dicer plays a minor role regulating this process suggesting that alternative biogenesis miRNAs pathways must be involved in human endometrial decidualization. PMID:22911744

Cusp Fracture Resistance of Maxillary Premolars Restored with the Bonded Amalgam Technique Using Various Luting Agents

PubMed Central

Marchan, Shivaughn M.; Coldero, Larry; White, Daniel; Smith, William A. J.; Rafeek, Reisha N.

2009-01-01

Objective. This in vitro study uses measurements of fracture resistance to compare maxillary premolars restored with the bonded amalgam technique using a new resin luting cement, glass ionomer, and resin-modified glass ionomer as the bonding agents. Materials. Eighty-five sound maxillary premolars were selected and randomly assigned to one of five test groups of 17 teeth each. One group of intact teeth served as the control. The remaining groups were prepared to a standard cavity form relative to the dimensions of the overall tooth and restored with amalgam alone or a bonded amalgam using one of three luting agents: RelyX Arc (a new resin luting cement), RelyX luting (a resin-modified glass ionomer), or Ketac-Cem μ (a glass ionomer) as the bonding agents. Each tooth was then subjected to compressive testing until catastrophic failure occurred. The mean loads at failure of each group were statistically compared using ANOVA with a post hoc Bonferroni test. Results. It was found that regardless of the luting cement used for the amalgam bonding technique, there was little effect on the fracture resistance of teeth. Conclusion. Cusp fracture resistance of premolars prepared with conservative MOD cavity preparations is not improved by using an amalgam-bonding technique compared to similar cavities restored with amalgam alone. PMID:20339450

In vitro investigation of heat transfer phenomenon in human immature teeth.

PubMed

Talebi, Maryam; Moghimi, Sahar; Shafagh, Mina; Kalani, Hadi; Mazhari, Fatemeh

2014-01-01

Background and aims. Heat generated within tooth during clinical dentistry can cause thermally induced damage to hard and soft components of the tooth (enamel, dentin and pulp). Geometrical characteristics of immature teeth are different from those of mature teeth. The purpose of this experimental and theoretical study was to investigate thermal changes in immature permanent teeth during the use of LED light-curing units (LCU). Materials and methods. This study was performed on the second mandibular premolars. This experimental investiga-tion was carried out for recording temperature variations of different sites of tooth and two dimensional finite element models were used for heat transfer phenomenon in immature teeth. Sensitivity analysis and local tests were included in the model validation phase. Results. Overall, thermal stimulation for 30 seconds with a low-intensity LED LCU increased the temperature from 28°C to 38°C in IIT (intact immature tooth) and PIT (cavity-prepared immature tooth). When a high-intensity LED LCU was used, tooth temperature increased from 28°C to 48°C. The results of the experimental tests and mathematical modeling illustrated that using LED LCU on immature teeth did not have any detrimental effect on the pulp temperature. Conclusion. Using LED LCU in immature teeth had no effect on pulp temperature in this study. Sensitivity analysis showed that variations of heat conductivity might affect heat transfer in immature teeth; therefore, further studies are required to determine thermal conductivity of immature teeth.

In Vitro Wear Resistance of Nano-Hybrid Composite Denture Teeth.

PubMed

Munshi, Nabeel; Rosenblum, Marc; Jiang, Shuying; Flinton, Robert

2017-04-01

To evaluate the wear resistance of nano-hybrid composite denture teeth as compared to two commonly used denture teeth: interpenetrating polymer network (IPN) and double crosslinking polymethylmethacrylate (PMMA) denture teeth. 18 styli and 18 disk specimens were prepared from the three denture tooth materials: nano-hybrid composite, IPN, and double crosslinking PMMA. The specimens were mounted in a two-body wear testing machine to simulate chewing in the complete denture. The amount of wear from the styli specimens were measured before and after using a digital micrometer, and the depth of the wear track from the disk specimens was measured using a noncontact 3D optical profilometer. The total wear from each denture tooth group was compared using one-way ANOVA with a 0.05 significance level. A Tukey post hoc test was used to determine differences between the three groups. The mean total wear in the nano-hybrid composite teeth group was 1.16 mm, SD = 0.5 mm, statistically significantly higher (p ≤ 0.0001) than the IPN (mean = 0.13 mm, SD = 0.05) and double crosslinking PMMA tooth groups (mean = 0.31 mm, SD = 0.19). There was no statistically significant difference between IPN denture teeth and double crosslinking PMMA denture teeth in the amount of wear. Nano-hybrid composite denture teeth exhibited statistically significantly more wear than the IPN and double crosslinking PMMA denture teeth. © 2015 by the American College of Prosthodontists.

Effect of reducing acid etching time on bond strength to noncarious and caries-affected primary and permanent dentin.

PubMed

Scheffel, Débora Lopes Salles; Ricci, Hérica Adad; de Souza Costa, Carlos Alberto; Pashley, David Henry; Hebling, Josimeri

2013-01-01

The purpose was to evaluate the effect of acid etching time on the bond strength of a simplified etch-and-rinse adhesive system to noncarious and caries-affected dentin of primary and permanent teeth. Twenty-four extracted primary and permanent teeth were divided into three groups, according to the acid etching time. Four teeth from each group were exposed to a microbiological caries-inducing protocol. After caries removal, noncarious and caries-affected dentin surfaces were etched with 37 percent phosphoric acid for five, 10, or 15 seconds prior to the application of Prime & Bond NT adhesive. Crowns were restored with resin composite and prepared for microtensile testing. Data were submitted to Kruskal-Wallis and Mann-Whitney tests (α=0.05). Higher bond strengths were obtained for noncarious dentin vs. caries-affected dentin for both primary and permanent teeth. Reducing the acid etching time from 15 to five seconds did not affect the bond strength to caries-affected or noncarious dentin in primary teeth. For permanent teeth, lower bond strength values were observed when the noncarious dentin was etched for five seconds, while no difference was seen between 10 and 15 seconds. For Prime & Bond NT, the etching of dentin for five seconds could be recommended for primary teeth, while 10 seconds would be the minimum time for permanent teeth.

Evaluation of a technique for color correction in restoring anterior teeth.

PubMed

Rauber, Gabrielle Branco; Bernardon, Jussara Karina; Vieira, Luiz Clovis Cardoso; Baratieri, Luiz Narciso

2017-09-01

This study aimed to evaluate the ability of the proposed technique in producing restorations that exhibit mimesis with tooth structure and to define a restorative clinical protocol. For this study a typodont was used. The right upper central incisor with Class IV lesion was restored with the layering technique (reference tooth, RT). For the left upper central incisor with Class IV lesion, six teeth were restored monochromatically (test teeth, TT), using DA3.5 (n = 3) and DA4 (n = 3) composite resins-resulting in six unsatisfactory color restorations. TT were divided into six groups depending on the color of unsatisfactory restoration and preparation depth. First, a preparation was realized on the labial surface with 0.5 mm, 0.7 mm or 1.0 mm of depth. A second preparation was then performed to reproduce the dentinal mamelons. Next, adhesive procedures were performed and the teeth restored. Opaque halo, opalescent halo and vestibular enamel were then reproduced by the addition of different composite resins. The RT and TT were photographed side by side in typodont to obtain six photographic prints. The photographs of the groups were subjected to visual evaluation by 120 volunteers via a questionnaire. Data were analyzed by the prevalence of answers, and Chi-square test was used to investigate the association between variables at .05 significance. Furthermore, ΔE of groups was evaluated in comparison RT. The results demonstrated that the moderate intensity restorations (DA3.5) with depths of 0.5 mm and 0.7 mm had the highest prevalence of acceptance. For severe intensity restorations (DA4), the preparation depth of 1.0 mm obtained better acceptance. The technique was able to modify the final color of Class IV restorations, producing satisfactory color restorations. This technique can be used for color correction in cases of Class IV restorations, in situations where there is no time for immediate layered restoration, and as a restorative technique. © 2017 Wiley Periodicals, Inc.

From the mouths of babes: dental caries in infants and children and the intensification of agriculture in mainland Southeast Asia.

PubMed

Halcrow, S E; Harris, N J; Tayles, N; Ikehara-Quebral, R; Pietrusewsky, M

2013-03-01

Many bioarchaeological studies have established a link between increased dental caries prevalence and the intensification of agriculture. However, research in Southeast Asia challenges the global application of this theory. Although often overlooked, dental health of infants and children can provide a sensitive source of information concerning health and subsistence change. This article investigates the prevalence and location of caries in the dentition of infants and children (less than 15 years of age) from eight prehistoric mainland Southeast Asian sites collectively spanning the Neolithic to late Iron Age, during which time rice agriculture became an increasingly important subsistence mode. Caries prevalence varied among the sites but there was no correlation with chronological change. The absence of evidence of a decline in dental health over time can be attributed to the relative noncariogenicity of rice and retention of broad-spectrum subsistence strategies. No differences in caries type indicating differences in dental health were found between the sites, apart from the Iron Age site of Muang Sema. There was a higher prevalence of caries in the deciduous dentition than the permanent dentition, likely due to a cariogenic weaning diet and the higher sensitivity of deciduous teeth to decay. The level of caries in the permanent dentition suggests an increased reliance on less cariogenic foods during childhood, including rice. The absence of a temporal decline in dental health of infants and children strengthens the argument that the relationship between caries and agricultural intensification in Southeast Asia was more complex than the general model suggests. Copyright © 2013 Wiley Periodicals, Inc.

Assessment of Retention and Resistance Form of Tooth Preparations for All Ceramic Restorations using Digital Imaging Technique.

PubMed

Muruppel, Alex M; Thomas, Joyce; Saratchandran, Sudeep; Nair, Dinesh; Gladstone, Sheeba; Rajeev, Milen M

2018-02-01

This in vitro study evaluated the resistance form of die preparations for all ceramic restorations and, thereby, explored the concept of effective taper and its correlation between the ideal in theory and actual in the clinical situation by analyzing the digital images of the die preparations. Scanned digital images of 114 die preparations for all ceramic restorations (n = 114) were collected from a dental laboratory. All the images were also analyzed digitally using Adobe Photoshop® software to analyze the degree of taper (angle of convergence) of each preparation and then applied the Zuckerman's circle, and the Lewis perpendicular methods were used to measure the resistance form. For the current study, the overall average degree of taper was found to be 20.9° (range, 2-80°), which is more than what is recommended by most previous studies and also sharply greater than the textbook ideal of 3 to 6°. Mean degree of taper for maxillary was 17.56° (anterior-10.50°, posterior-23.7°), and for mandibular teeth, it was 25.22° (anterior-15°, posterior- 28.45°). Out of the 64 analyzed images of maxillary teeth, 61 presented resistance form, while 3 were without it. Out of the 50 mandibular teeth analyzed, 38 possessed resistance form, whereas 12 were without. All the anterior teeth showed resistance form irrespective of the arch. The degree of taper showed a significant relationship with resistance and retention form, which was inversely proportional to each other. The recommended "degree of taper" is not always the clinically achievable as advocated in textbooks, as it is modified by various factors in the actual clinical situation. The study provides scientific background regarding the relationship between the degree of taper with resistance and retention form, and the relationship was found to be inversely proportional to each other. The recommended "degree of taper" is not always the clinically achievable as advocated in textbooks, and it is modified by various modifying or limiting factors in the actual clinical situation.

The success rate of bupivacaine and lidocaine as anesthetic agents in inferior alveolar nerve block in teeth with irreversible pulpitis without spontaneous pain

PubMed Central

Yosefi, Mohammad Hosein; Nakhaee, Nouzar

2015-01-01

Objectives Achieving adequate anesthesia with inferior alveolar nerve blocks (IANB) is of great importance during dental procedures. The aim of the present study was to assess the success rate of two anesthetic agents (bupivacaine and lidocaine) for IANB when treating teeth with irreversible pulpitis. Materials and Methods Sixty volunteer male and female patients who required root canal treatment of a mandibular molar due to caries participated in the present study. The inclusion criteria included prolonged pain to thermal stimulus but no spontaneous pain. The patients were randomly allocated to receive either 2% lidocaine with 1:80,000 epinephrine or 0.5% bupivacaine with 1:200,000 epinephrine as an IANB injection. The sensitivity of the teeth to a cold test as well as the amount of pain during access cavity preparation and root canal instrumentation were recorded. Results were statistically analyzed with the Chi-Square and Fischer's exact tests. Results At the final step, fifty-nine patients were included in the study. The success rate for bupivacaine and lidocaine groups were 20.0% and 24.1%, respectively. There was no significant difference between the two groups at any stage of the treatment procedure. Conclusions There was no difference in success rates of anesthesia when bupivacaine and lidocaine were used for IANB injections to treat mandibular molar teeth with irreversible pulpitis. Neither agent was able to completely anesthetize the teeth effectively. Therefore, practitioners should be prepared to administer supplemental anesthesia to overcome pain during root canal treatment. PMID:25984478

Involvement of human decidual cell-expressed tissue factor in uterine hemostasis and abruption.

PubMed

Lockwood, C J; Paidas, M; Murk, W K; Kayisli, U A; Gopinath, A; Huang, S J; Krikun, G; Schatz, F

2009-11-01

Vascular injury increases access and binding of plasma-derived factor VII to perivascular cell membrane-bound tissue factor (TF). The resulting TF/VIIa complex promotes hemostasis by cleaving pro-thrombin to thrombin leading to the fibrin clot. In human pregnancy, decidual cell-expressed TF prevents decidual hemorrhage (abruption). During placentation, trophoblasts remodel decidual spiral arteries into high conductance vessels. Shallow trophoblast invasion impedes decidual vascular conversion, producing an inadequate uteroplacental blood flow that elicits abruption-related placental ischemia. Thrombin induces several biological effects via cell surface protease activated receptors. In first trimester human DCs thrombin increases synthesis of sFlt-1, which elicits placental ischemia by impeding angiogenesis-related decidual vascular remodeling. During pregnacy, the fibrillar collagen-rich amnion and choriodecidua extracellular matrix (ECM) provides greater than additive tensile strength and structural integrity. Thrombin acts as an autocrine/paracrine mediator that degrades these ECMs by augmenting decidual cell expression of: 1) matrix metalloproteinases and 2) interleukin-8, a key mediator of abruption-associated decidual infiltration of neutrophils, which express several ECM degrading proteases. Among the cell types at the maternal fetal interface at term, TF expression is highest in decidual cells indicating that this TF meets the hemostatic demands of labor and delivery. TF expression in cultured term decidual cells is enhanced by progestin and thrombin suggesting that the maintenance of elevated circulating progesterone provides hemostatic protection and that abruption-generated thrombin acts in an autocrine/paracrine fashion on decidual cells to promote hemostasis via enhanced TF expression.

Microleakage of stainless steel crowns placed on intact and extensively destroyed primary first molars: an in vitro study.

PubMed

Seraj, Bahman; Shahrabi, Mahdi; Motahari, Pouria; Ahmadi, Rahil; Ghadimi, Sara; Mosharafian, Shahram; Mohammadi, Kaveh; Javad Kharazifard, Mohammad

2011-01-01

The purpose of this investigation was to evaluate the effect of residual tooth structure on the microleakage of stainless steel crowns cemented with glass ionomer on primary maxillary and mandibular first molars. Thirty extracted primary molars were divided into 2 groups: group 1 included intact teeth; and group 2 included extensively carious samples. Each tooth received standard preparation, and each crown was luted with G-CEM on its specific specimen. Teeth were loaded vertically and transferred to distilled water. After thermocycling and immersing in methylene blue solution, the teeth were sectioned and examined microscopically for microleakage. Data were analyzed using Mann-Whitney U and Wilcoxon signed-rank tests. All specimens (intact and damaged teeth) had microleakage, although most of these presented only minimum microleakage. No statistically significant differences were found in the microleakage of sound and extensively carious teeth on either the buccal (P=.62) or lingual (P=.65) side. Buccal (P=.73) and lingual (P=.63) surfaces showed similar microleakage scores in primary maxillary and mandibular molars. There was no significant difference in the microleakage of sound or extensively carious teeth and primary maxillary or mandibular first molars.

Cerec omnicam and the virtual articulator--a case report.

PubMed

Fritzsche, G

2013-01-01

This case report demonstrates how two opposing teeth were restored with full crowns using Cerec software version 4.2 (pre-release version). In addition, an anterior tooth was provided with a veneer. The situation was scanned with the Cerec Omnicam. The new virtual articulator was used for the design to obtain correct dynamic contacts. The Cerec Omnicam can scan the entire situation prior to preparation without the help of an assistant, as no surface pretreatment is necessary. The locations of the occlusal contacts can be marked with articulating paper and are indicated on the virtual models. Selective deletion of individual areas allows the prepared teeth to be rescanned, considerably speeding up the workflow. A video demonstration is available of the acquisition and design procedure.

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

PubMed Central

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

2015-01-01

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

Efficient digitalization method for dental restorations using micro-CT data

NASA Astrophysics Data System (ADS)

Kim, Changhwan; Baek, Seung Hoon; Lee, Taewon; Go, Jonggun; Kim, Sun Young; Cho, Seungryong

2017-03-01

The objective of this study was to demonstrate the feasibility of using micro-CT scan of dental impressions for fabricating dental restorations and to compare the dimensional accuracy of dental models generated from various methods. The key idea of the proposed protocol is that dental impression of patients can be accurately digitized by micro-CT scan and that one can make digital cast model from micro-CT data directly. As air regions of the micro-CT scan data of dental impression are equivalent to the real teeth and surrounding structures, one can segment the air regions and fabricate digital cast model in the STL format out of them. The proposed method was validated by a phantom study using a typodont with prepared teeth. Actual measurement and deviation map analysis were performed after acquiring digital cast models for each restoration methods. Comparisons of the milled restorations were also performed by placing them on the prepared teeth of typodont. The results demonstrated that an efficient fabrication of precise dental restoration is achievable by use of the proposed method.

Interim overdentures.

PubMed

Fenton, A H

1976-07-01

The construction of an interim overdenture using existing removable partial dentures with natural tooth crowns and artificial teeth can be a simple and economical method of providing patients with dentures while tissues heal and teeth are prepared and restored. A more definite prognosis for both the patient and his remaining dentition can be established before the final overdenture is completed. The procedures necessary to provide three types of interim overdentures have been outlined. Patients tolerate this method of changing their dentitions extremely well.

Evaluation of apically extruded debris during root canal preparation in primary molar teeth using three different rotary systems and hand files.

PubMed

Topçuoğlu, Gamze; Topçuoğlu, Hüseyin Sinan; Akpek, Firdevs

2016-09-01

To assess the amount of debris extruded apically during root canal preparation using various nickel titanium instrumentation systems and hand files in primary molar teeth. Sixty extracted primary first mandibular molar human teeth were randomly assigned to four groups (n = 15 teeth for each group). The canals were then instrumented with the following instrument systems: Revo-S, Mtwo, ProTaper Next, and hand files. Apically extruded debris during instrumentation was collected into pre-weighed Eppendorf tubes. The Eppendorf tubes were then stored in an incubator at 70°C for 5 days. The weight of the dry extruded debris was established by subtracting the pre-instrumentation and post-instrumentation weight of the Eppendorf tubes for each group. The data were analyzed using one-way analysis of variance (anova) and Tukey's post hoc tests. ProTaper Next files were associated with less apically extruded debris than the Mtwo, Revo-S, and hand files (P < 0.05). Hand files extruded more debris than Mtwo and Revo-S instruments (P < 0.05), but there was no significant difference found between the Mtwo and Revo-S instruments (P > 0.05). All instruments were associated with apical extrusion of debris. ProTaper Next files caused less debris extrusion compared to the other systems used. © 2015 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Dental caries and their treatment needs in 3-5 year old preschool children in a rural district of India.

PubMed

Gupta, Devanand; Momin, Rizwan K; Mathur, Ayush; Srinivas, Kavuri Teja; Jain, Ankita; Dommaraju, Neelima; Dalai, Deepak Ranjan; Gupta, Rajendra Kumar

2015-04-01

Dental problems in the preschool children are neglected by their parents as the deciduous teeth are going to shed off, and hence considered to be of no importance and more of economic burden if attended to them. This study was to determine the caries prevalence in preschool children (3-5-year-old) of rural Moradabad district, to analyze the specific pattern of dental caries experience in this population and to assess the treatment needs among them. Children within the age group of 3-5 years attending Anganwadi centers of rural Moradabad district were included in the study. Caries diagnosis was based on decayed, extracted, filled surface (defs) and the treatment needs were recorded using World Health Organization (WHO) oral health assessment form 1997. Out of 1,500 children examined, 48.7% males and 52.6% females did not require any treatment. The mean decayed, extracted, filled teeth (deft) value was found to be significantly high in 5-year-old participants when compared to 3-year-old participants (P < 0.01). Majority of the children required one surface filling followed by two surface fillings, caries arresting sealant care, extraction, crown bridge element, pulp care, and space maintainer. The most common pattern was pit and fissure, then maxillary anterior pattern, posterior proximal pattern, and posterior buccal lingual smooth surface pattern. The mean deft value was higher in males as compared to females. There is a greater need for oral health education among parents and teachers.

Applications of Stem Cells in Interdisciplinary Dentistry and Beyond: An Overview

PubMed Central

Rai, S; Kaur, M; Kaur, S

2013-01-01

In medicine stem cell–based treatments are being used in conditions like Parkinson's disease, neural degeneration following brain injury, cardiovascular diseases, diabetes, and autoimmune diseases. In dentistry, recent exciting discoveries have isolated dental stem cells from the pulp of the deciduous and permanent teeth, from the periodontal ligament, and an associated healthy tooth structure, to cure a number of diseases. The aim of the study was to review the applications of stem cells in various fields of dentistry, with emphasis on its banking, and to understand how dental stem cells can be used for regeneration of oral and non-oral tissues conversely. A Medline search was done including the international literature published between 1989 and 2011. It was restricted to English language articles and published work of past researchers including in vitro and in vivo studies. Google search on dental stem cell banking was also done. Our understanding of mesenchymal stem cells (MSC) in the tissue engineering of systemic, dental, oral, and craniofacial structures has advanced tremendously. Dental professionals have the opportunity to make their patients aware of these new sources of stem cells that can be stored for future use, as new therapies are developed for a range of diseases and injuries. Recent findings and scientific research articles support the use of MSC autologously within teeth and other accessible tissue harvested from oral cavity without immunorejection. A future development of the application of stem cells in interdisciplinary dentistry requires a comprehensive research program. PMID:23919198

Type and location of findings in dental panoramic tomographs in 7-12-year-old orthodontic patients.

PubMed

Pakbaznejad Esmaeili, Elmira; Ekholm, Marja; Haukka, Jari; Waltimo-Sirén, Janna

2016-01-01

The Radiation and Nuclear Safety Authority in Finland has paid attention to the large numbers of dental panoramic tomographs (DPTs), particularly in 7-12-year-old children. The majority of these radiographs are taken for orthodontic reasons. Because of the high radiosensitivity of children, the size of the irradiated field should be carefully chosen to yield the necessary diagnostic information at the lowest possible dose. The purpose of the present study was, therefore, to assess the outcome of DPTs within this age group in terms of type and location of pathological findings. It was also hypothesized that DPTs of orthodontic patients rarely display unrestored caries. Four hundred and forty-one DPTs, taken of 7-12-year-old children in 2010-2014, were randomly sampled. The 413 of them (94%) that had been taken for orthodontic reasons were analysed. All pathologic findings were restricted to the tooth-bearing area and there was no pathology in the bone structure or any incidental findings in the region of temporomandibular joint. Unlike hypothesized, 27% of the orthodontic DPTs showed caries in deciduous teeth and 16% in permanent teeth. A sub-sample of 229 DPTs, analysed for developmental dental and occlusal problems, most commonly displayed crowding (50%), positional anomalies and local problems with tooth eruption (32%), as well as hyperodontia (15%). Inclusion of only the actual area of interest in the image field should be considered case-specifically as a means to reduce the radiation dose.

Food insecurity and dental caries in schoolchildren: a cross-sectional survey in the western Brazilian Amazon.

PubMed

Frazão, Paulo; Benicio, Maria H D; Narvai, Paulo C; Cardoso, Marly A

2014-06-01

We analyzed the association between food insecurity and dental caries in 7- to 9-yr-old schoolchildren. We performed a cross-sectional survey nested in a population-based cohort study of 203 schoolchildren. The participants lived in the urban area of a small town within the western Brazilian Amazon. Dental examinations were performed according to criteria recommended by the World Health Organization. The number of decayed deciduous and permanent teeth as a count variable was the outcome measure. Socio-economic status, food security, behavioral variables, and child nutritional status, measured by Z-score for body mass index (BMI), were investigated, and robust Poisson regression models were used. The results showed a mean (SD) of 3.63 (3.26) teeth affected by untreated caries. Approximately 80% of schoolchildren had at least one untreated decayed tooth, and nearly 60% lived in food-insecure households. Sex, household wealth index, mother's education level, and food-insecurity scores were associated with dental caries in the crude analysis. Dental caries was 1.5 times more likely to be associated with high food-insecurity scores after adjusting for socio-economic status and sex. A significant dose-response relationship was observed. In conclusion, food insecurity is highly associated with dental caries in 7- to 9-yr-old children and may be seen as a risk factor. These findings suggest that food-security policies could reduce dental caries. © 2014 Eur J Oral Sci.

Craniofacial structures and dental development in three patients with Nager syndrome.

PubMed

Halonen, Katri; Hukki, Jyri; Arte, Sirpa; Hurmerinta, Kirsti

2006-11-01

In Finland, 3 patients have been diagnosed with Nager syndrome (NS) during the last 17 years. Thus the incidence for NS in Finland is 3:1,000,000. The craniofacial structures and dental development of these patients were studied clinically and radiographically at the age of 3-4 years, and compared to age-matched controls and to the norms of the Finnish population. The striking structural finding was a severely short, retrognathic and posteriorly rotated mandible. Especially the ramus was deficient; its height was, on average, less than one-third of that of the control group. All children were tracheostomized neonatally. At the age of 3-4, the lower pharyngeal airway was still severely obstructed or completely closed. Nasopharyngeal airway was wide and the soft palate was missing in all patients. All patients had a complete deciduous dentition, but agenesis of permanent teeth (ranging from 2-10 missing teeth) was observed in each patient. Accelerated dental development was found in two subjects. Condylar ankylosis or severely limited mouth opening were observed. The present findings give new information and quantify earlier observations of craniofacial structures and dental development in NS. Analysis of facial structures suggests that if surgical intervention is needed to enable better breathing, the goal of the structural correction should be aimed at the most deficient structure, namely the ramus height. As a result of severe dentofacial deviation, a treatment process through the growth requires multidisciplinary teamwork of surgeons, pediatrists, orthodontists and prosthodontists.

Critical role of mTOR, PPARγ and PPARδ signaling in regulating early pregnancy decidual function, embryo viability and feto-placental growth.

PubMed

Roberti, Sabrina L; Higa, Romina; White, Verónica; Powell, Theresa L; Jansson, Thomas; Jawerbaum, Alicia

2018-06-01

What are the consequences of inhibiting mTOR, the mechanistic target of rapamycin (mTOR), and the peroxisome proliferator activated receptor gamma (PPARγ) and PPARδ pathways in the early post-implantation period on decidual function, embryo viability and feto-placental growth in the rat? mTOR inhibition from Days 7 to 9 of pregnancy in rats caused decidual PPARγ and PPARδ upregulation on Day 9 of pregnancy and resulted in embryo resorption by Day 14 of pregnancy. PPARγ and PPARδ inhibition differentially affected decidual mTOR signaling and levels of target proteins relevant to lipid histotrophic nutrition and led to reduced feto-placental weights on Day 14 of pregnancy. Although mTOR, PPARγ and PPARδ are nutrient sensors important during implantation, the role of these signaling pathways in decidual function and how they interact in the early post-implantation period are unknown. Perilipin 2 (PLIN2) and fatty acid binding protein 4 (FABP4), two adipogenic proteins involved in lipid histotrophic nutrition, are targets of mTOR and PPAR signaling pathways in a variety of tissues. Rapamycin (mTOR inhibitor, 0.75 mg/kg, sc), T0070907 (PPARγ inhibitor, 0.001 mg/kg, sc), GSK0660 (PPARδ inhibitor, 0.1 mg/kg, sc) or vehicle was injected daily to pregnant rats from Days 7 to 9 of pregnancy and the studies were performed on Day 9 of pregnancy (n = 7 per group) or Day 14 of pregnancy (n = 7 per group). On Day 9 of pregnancy, rat decidua were collected and prepared for western blot and immunohistochemical studies. On Day 14 of pregnancy, the resorption rate, number of viable fetuses, crown-rump length and placental and decidual weights were determined. Inhibition of mTOR in the early post-implantation period led to a reduction in FABP4 protein levels, an increase in PLIN2 levels and an upregulation of PPARγ and PPARδ in 9-day-pregnant rat decidua. Most embryos were viable on Day 9 of pregnancy but had resorbed by Day 14 of pregnancy. This denotes a key function of mTOR in the post-implantation period and suggests that activation of PPAR signaling was insufficient to compensate for impaired nutritional/survival signaling induced by mTOR inhibition. Inhibition of PPARγ signaling resulted in decreased decidual PLIN2 and FABP4 protein expression as well as in inhibition of decidual mTOR signaling in Day 9 of pregnancy. This treatment also reduced feto-placental growth on Day 14 of pregnancy, revealing the relevance of PPARγ signaling in sustaining post-implantation growth. Moreover, following inhibition of PPARδ, PLIN2 levels were decreased and mTOR complex 1 and 2 signaling was altered in decidua on Day 9 of pregnancy. On Day 14 of pregnancy, PPARδ inhibition caused reduced feto-placental weight, increased decidual weight and increased resorption rate, suggesting a key role of PPARδ in sustaining post-implantation development. Not applicable. This is an in vivo animal study and the relevance of the results for humans remains to be established. The early post-implantation period is a critical window of development and changes in the intrauterine environment may cause embryo resorption and lead to placental and fetal growth restriction. mTOR, PPARγ and PPARδ signaling are decidual nutrient sensors with extensive cross-talk that regulates adipogenic proteins involved in histotrophic nutrition and important for embryo viability and early placental and fetal development and growth. Funding was provided by the Agencia Nacional de Promoción Científica y Tecnológica de Argentina (PICT 2014-411 and PICT 2015-0130), and by the International Cooperation (Grants CONICET-NIH-2014 and CONICET-NIH-2017) to A.J. and T.J. The authors have no conflicts of interest.

A comparative evaluation of antibacterial effectiveness of sodium hypochlorite, Curcuma longa, and Camellia sinensis as irrigating solutions on isolated anaerobic bacteria from infected primary teeth.

PubMed

Dhariwal, Neha Shashikant; Hugar, Shivayogi M; Harakuni, Sheetal; Sogi, Suma; Assudani, Harsha G; Mistry, Laresh Naresh

2016-01-01

In endodontics, most of the commercial intra-canal medicaments have cytotoxic reactions and because of their inability to eliminate bacteria from dentinal tubules, recent medicine has turned its attention to the usage of biologic medication prepared from natural plants. The literature to testify the efficacy of natural alternatives in primary teeth is meagre and its effects as irrigating solutions need to be evaluated. To evaluate the antibacterial effectiveness of sodium hypochlorite, ethanolic extracts of Curcuma longa (turmeric) and Camellia sinensis (green tea) as irrigating solutions against the anaerobic bacteria isolated from the root canals of infected primary teeth. Thirty patients were selected based on the selected inclusion and exclusion criteria. Preoperative radiographs were taken. Rubber dam isolation and working length estimation were done, following which thirty samples were taken from the root canals of infected primary teeth using sterile absorbent paper points and transferred to tubes containing thioglycolate transport medium. The bacteria were then isolated using standard microbiological protocols and were subjected to antibiotic sensitivity testing using the three test irrigants. SPSS 18 software using Chi-square test was used for statistical analysis. The most commonly isolated bacteria included Porphyromonas sp., Bacteroides fragilis, Peptostreptococcus, and Staphylococcus aureus. Sodium hypochlorite and C. longa (turmeric) showed good antibacterial effect and were effective against most of the isolated bacteria. There was statistically significant difference in the antibacterial effect among the three tested groups (P < 0.001). The least effective was C. sinensis (green tea). The infected primary teeth almost always present with a polymicrobial structure with a wide variety of anaerobic bacteria. The chemo-mechanical preparation plays an important role in eradicating the population of predominant micro-organisms in treating these teeth with promising effects with the use of newer test irrigants while avoiding the side effects of sodium hypochlorite.

Prevalence of early childhood caries in a population of children with history of maltreatment.

PubMed

Valencia-Rojas, Nancy; Lawrence, Herenia P; Goodman, Deborah

2008-01-01

The purpose of this study was to investigate the prevalence of early childhood caries (ECC) in a population of maltreated children in Toronto, Ontario, Canada. The sample consisted of preschool-aged children (2 to 6 years) admitted to the care of the Children's Aid Society of Toronto (CAST) between 1991 and 2004. Data were collected by reviewing the dental and social workers' records of CAST ECC was determined using the decayed, missing, and filled deciduous teeth (dmft) index. The type and severity of maltreatment were obtained from the Eligibility Spectrum. The study included 66 children: 37 (56 percent) boys and 29 (44 percent) girls, with an average age of 4.1 years [standard deviation (SD) = 1.2]. Four (6 percent) children had evidence of dental injury, and none had teeth filled or extracted as a result of decay ECC was observed in 58 percent of the abused children. Of these, the mean decayed teeth ("dt") value was 5.63 (SD = 4.17, n = 38) and 3.24 (SD= 4.21) for the whole sample (n = 66). The proportion of children with untreated caries was 57 percent among "neglected" children (n = 53) and 62 percent in physically/sexually abused cases (n = 13). Logistic regression revealed that children in permanent CAST care and those in its care more than once were significantly less likely to have experienced caries. Abused and neglected young children had higher levels of tooth decay than the general population of 5-year-olds in Toronto (30 percent prevalence, mean dt= 0.42, SD = 1.20, n = 3185). However, this study did not find any difference in ECC prevalence between children with different types of maltreatment. The study did find that CAST services had a protective effect on children's oral health, which supports the recommendation that child protection services should investigate possible dental neglect in physical/sexual abuse and neglect cases.

Permafrost Ecosystem Warming Prototype: Installation, Operation, and Initial Site Characterization

DTIC Science & Technology

2013-11-01

report Approved for public release; distribution is unlimited. Prepared for US Army Corps of Engineers Washington , DC 20314-1000 Monitored by...in 3 m diameter plots in a temperate deciduous forest. To further develop the prototype for an arctic climate, a similar test system was installed...growth trees and shrubs. The site was chosen because of its permafrost characteristics, ease of access, and its close proximity to the CRREL Fairbanks

Winter-Deciduous versus Evergreen Habit in Mediterranean Regions: A Model

Treesearch

Mark A. Blumler

1991-01-01

Although winter-deciduous species are presumed to be "out-of-phase" with the mediterranean climate regime, distributional evidence suggests some taxa may be more tolerant of summer drought than evergreen sclerophylls. Deciduous species possess several features that confer advantage in extreme summer dry regions: drought-deciduousness, an efficient response to...

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

PubMed

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

2005-09-01

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

Regulation and Measurement of the Heat Generated by Automatic Tooth Preparation in a Confined Space.

PubMed

Yuan, Fusong; Zheng, Jianqiao; Sun, Yuchun; Wang, Yong; Lyu, Peijun

2017-06-01

The aim of this study was to assess and regulate heat generation in the dental pulp cavity and circumambient temperature around a tooth during laser ablation with a femtosecond laser in a confined space. The automatic tooth preparing technique is one of the traditional oral clinical technology innovations. In this technique, a robot controlled an ultrashort pulse laser to automatically complete the three-dimensional teeth preparing in a confined space. The temperature control is the main measure for protecting the tooth nerve. Ten tooth specimens were irradiated with a femtosecond laser controlled by a robot in a confined space to generate 10 teeth preparation. During the process, four thermocouple sensors were used to record the pulp cavity and circumambient environment temperatures with or without air cooling. A statistical analysis of the temperatures was performed between the conditions with and without air cooling (p < 0.05). The recordings showed that the temperature with air cooling was lower than that without air cooling and that the heat generated in the pulp cavity was lower than the threshold for dental pulp damage. These results indicate that femtosecond laser ablation with air cooling might be an appropriate method for automatic tooth preparing.

Changes in global gene expression during in vitro decidualization of rat endometrial stromal cells

PubMed Central

Vallejo, Griselda; Maschi, Darío; Citrinovitz, Ana Cecilia Mestre; Aiba, Kazuhiro; Maronna, Ricardo; Yohai, Victor; Ko, Minoru S. H.; Beato, Miguel; Saragüeta, Patricia

2009-01-01

During the preimplantation phase of pregnancy the endometrial stroma differentiates into decidua, a process that implies numerous morphological changes and is an example of physiological transdifferentiation. Here we show that UIII rat endometrial stromal cells cultured in the presence of calf serum acquired morphological features of decidual cells and expressed decidual markers. To identify genes involved in decidualization we compared gene expression patterns of control and decidualized UIII cells using cDNA microarray. We found 322 annotated genes exhibiting significant differences in expression (>3 fold, FDR > 0.005), of which 312 have not been previously related to decidualization. Analysis of overrepresented functions revealed that protein synthesis, gene expression and chromatin architecture and remodeling are the most relevant modified functions during decidualization. Relevant genes are also found in the functional terms differentiation, cell proliferation, signal transduction, and matrix/structural proteins. Several of these new genes involved in decidualization (Csdc2, Trim27, Eef1a1, Bmp1, Wt1, Aes, Gna12, and Men1) are shown to be also regulated in uterine decidua during normal pregnancy. Thus, the UIII cell culture model will allow future mechanistic studies to define the transcriptional network regulating reprogramming of stromal cells into decidual cells. PMID:19780023

Progesterone and DNA Damage Encourage Uterine Cell Proliferation and Decidualization through Up-regulating Ribonucleotide Reductase 2 Expression during Early Pregnancy in Mice*

PubMed Central

Lei, Wei; Feng, Xu-Hui; Deng, Wen-Bo; Ni, Hua; Zhang, Zhi-Rong; Jia, Bo; Yang, Xin-Ling; Wang, Tong-Song; Liu, Ji-Long; Su, Ren-Wei; Liang, Xiao-Huan; Qi, Qian-Rong; Yang, Zeng-Ming

2012-01-01

Embryo implantation into the maternal uterus is a crucial step for the successful establishment of mammalian pregnancy. Following the attachment of embryo to the uterine luminal epithelium, uterine stromal cells undergo steroid hormone-dependent decidualization, which is characterized by stromal cell proliferation and differentiation. The mechanisms underlying steroid hormone-induced stromal cell proliferation and differentiation during decidualization are still poorly understood. Ribonucleotide reductase, consisting of two subunits (RRM1 and RRM2), is a rate-limiting enzyme in deoxynucleotide production for DNA synthesis and plays an important role in cell proliferation and tumorgenicity. Based on our microarray analysis, Rrm2 expression was significantly higher at implantation sites compared with interimplantation sites in mouse uterus. However, the expression, regulation, and function of RRM2 in mouse uterus during embryo implantation and decidualization are still unknown. Here we show that although both RRM1 and RRM2 expression are markedly induced in mouse uterine stromal cells undergoing decidualization, only RRM2 is regulated by progesterone, a key regulator of decidualization. Further studies showed that the induction of progesterone on RRM2 expression in stromal cells is mediated by the AKT/c-MYC pathway. RRM2 can also be induced by replication stress and DNA damage during decidualization through the ATR/ATM-CHK1-E2F1 pathway. The weight of implantation sites and deciduoma was effectively reduced by specific inhibitors for RRM2. The expression of decidual/trophoblast prolactin-related protein (Dtprp), a reliable marker for decidualization in mice, was significantly reduced in deciduoma and steroid-induced decidual cells after HU treatment. Therefore, RRM2 may be an important effector of progesterone signaling to induce cell proliferation and decidualization in mouse uterus. PMID:22403396

Scanning electron microscopy comparison of the cleaning efficacy of a root canal system by Nd:YAG laser and rotary instruments.

PubMed

Samiei, Mohammad; Pakdel, Seyyed Mahdi Vahid; Rikhtegaran, Sahand; Shakoei, Sahar; Ebrahimpour, Delaram; Taghavi, Pedram

2014-08-01

This study evaluated the cleaning efficacy of a root canal system by Nd:YAG laser and rotary instruments. Sixty single-rooted human teeth were divided into four experimental groups (n=15). In the first group the teeth were prepared with a step-back technique using conventional K-files. In the second and third groups, tooth preparation was carried out using Nd:YAG laser and rotary NiTi instruments, respectively. Teeth in the fourth group were prepared by combined laser and rotary methods. The smear layer remaining on canal walls was then assessed by scanning electron microscopy in the coronal, middle, and apical portions. The comparison of smear layer removal efficacy between groups was carried out by Kruskal-Wallis and Mann-Whitney U tests. The mean grades of smear layer removal in rotary-laser, rotary, laser and step-back techniques were 1.34 ± 0.18, 2.2 ± 0.28, 1.91 ± 0.25, and 2.42 ± 0.19, respectively. On the whole, differences between rotary-laser and rotary groups, step-back, and the three other techniques (rotary, laser, and rotary-laser) were significant at p=0.034. Based on the findings of this study, the cleaning efficacy of rotary, laser, and rotary-laser techniques were better than the step-back technique and the combined laser and rotary technique was the most efficient method.

Influence of Iatrogenic Gaps, Cement Type, and Time on Microleakage of Cast Posts Using Spectrophotometer and Glucose Filtration Measurements.

PubMed

Al-Madi, Ebtissam M; Al-Saleh, Samar A; Al-Khudairy, Reem I; Aba-Hussein, Taibah W

2018-04-06

To determine the influence of iatrogenic gaps, type of cement, and time on microleakage of cast posts using spectrophotometer and glucose filtration measurements. Forty-eight single-rooted teeth were divided into eight groups of six teeth each. Teeth were instrumented and obturated, and a cast post was fabricated. In addition to two control groups (positive and negative), a total of six groups were prepared: In four groups, an artificial 2- to 3-mm gap was created between post and residual gutta percha (GP), and two groups were prepared with intimate contact between post and residual GP. Posts were cemented with either zinc phosphate cement or resin cement. Leakage through the post after 1, 8, 14, and 20 days was measured using a glucose penetration model with two different reading methods. Mixed analysis of variance tests were performed to analyze the data. The presence of a gap between the apical end of the post and the most coronal portion of the GP remaining in the root canal after post space preparation increased microleakage significantly. However, microleakage was significantly less when the gap was refilled with GP compared to no gap. There was no difference in leakage between luting cements used. It was concluded that none of the cements were able to prevent microleakage. However, the addition of GP to residual GP did increase the sealing ability.

In vitro assessment of retention and resistance failure loads of two preparation designs for maxillary anterior teeth.

PubMed

Bintivanou, Aimilia; Pissiotis, Argirios; Michalakis, Konstantinos

2017-04-01

Parallel labiolingual walls and the preservation of the cingulum in anterior tooth preparations have been advocated. However, their contribution to retention and resistance form has not been evaluated. The purpose of this in vitro study was to evaluate the retention and resistance failure loads of 2 preparation designs for maxillary anterior teeth. Forty metal restorations were fabricated and paired with 40 cobalt-chromium prepared tooth analogs. Twenty of the specimens had parallel buccolingual walls at the cervical part (group PBLW; the control group), whereas the remaining 20 had converging buccolingual walls (group CBLW; the experimental group). The restorations were cemented to the tooth analogs with a resin-modified glass ionomer luting agent. Ten specimens from each group were subjected to tensile loading with a universal testing machine; the rest were subjected to compression loading until failure. Descriptive statistics and the independent t test (α=.05) were used to determine the effect of failure loads in the tested groups. The independent t test revealed statistically significant differences between the tested groups in tensile loading (P<.001) and in compressive loading (P<.001). The PBLW group presented a higher tensile failure load than the CBLW. On the contrary, the PBLW group presented a smaller compression failure load than the CBLW. Parallelism of the buccolingual axial walls in anterior maxillary teeth increased the retention form but decreased the resistance form. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Resistance of full veneer metal crowns with different forms of axial grooves

NASA Astrophysics Data System (ADS)

Hidayat, A. S.; Masulili, C.; Indrasari, M.

2017-08-01

Dental crowns or bridges can occasionally come loose or separate from the tooth during chewing, particularly when they are situated on small, short, and conical teeth. The main cause of this separation is a lack of retention and resistance to the tooth. There are several methods available to increase the retention and resistance of the crown during both inlay and onlay preparation, including parallelism, groove preparation, crown build-up, and surface roughness. The aim of this study was to determine the differences in resistance of full veneer metal crowns with various forms of groove preparation. The study involved the compressive strength testing of a total of 24 specimens, namely six specimens without groove preparation, six specimens with box-shaped grooves, six specimens with V-shaped grooves, and six specimens with half round grooves. The mean values of the metal crowns that separated from the teeth during testing were 27.97 ± 1.08 kgF for the crowns with box-shaped grooves, 6.15 ± 0.22 kgF for those with V-shaped grooves, 1.77 ± 0.12 kgF for those with half round grooves, and 0.95 ± 0.13 kgF for those without grooves. This study found that the resistance is best in crowns with box-shaped grooves, followed by those with V-shaped grooves, half round grooves, and those without groove. When clinicians are working on short and conical molar teeth, it is therefore recommended that box-shaped grooves are used to increase the resistance of the crown.

Human decidual stromal cells secrete soluble pro-apoptotic factors during decidualization in a cAMP-dependent manner.

PubMed

Leno-Durán, E; Ruiz-Magaña, M J; Muñoz-Fernández, R; Requena, F; Olivares, E G; Ruiz-Ruiz, C

2014-10-10

Is there a relationship between decidualization and apoptosis of decidual stromal cells (DSC)? Decidualization triggers the secretion of soluble factors that induce apoptosis in DSC. The differentiation and apoptosis of DSC during decidualization of the receptive decidua are crucial processes for the controlled invasion of trophoblasts in normal pregnancy. Most DSC regress in a time-dependent manner, and their removal is important to provide space for the embryo to grow. However, the mechanism that controls DSC death is poorly understood. The apoptotic response of DSC was analyzed after exposure to different exogenous agents and during decidualization. The apoptotic potential of decidualized DSC supernatants and prolactin (PRL) was also evaluated. DSC lines were established from samples of decidua from first trimester pregnancies. Apoptosis was assayed by flow cytometry. PRL production, as a marker of decidualization, was determined by enzyme-linked immunosorbent assay. DSCs were resistant to a variety of apoptosis-inducing substances. Nevertheless, DSC underwent apoptosis during decidualization in culture, with cAMP being essential for both apoptosis and differentiation. In addition, culture supernatants from decidualized DSC induced apoptosis in undifferentiated DSC, although paradoxically these supernatants decreased the spontaneous apoptosis of decidual lymphocytes. Exogenously added PRL did not induce apoptosis in DSC and an antibody that neutralized the PRL receptor did not decrease the apoptosis induced by supernatants. Further studies are needed to examine the involvement of other soluble factors secreted by decidualized DSC in the induction of apoptosis. The present results indicate that apoptosis of DSC occurs in parallel to differentiation, in response to decidualization signals, with soluble factors secreted by decidualized DSC being responsible for triggering cell death. These studies are relevant in the understanding of how the regression of decidua, a crucial process for successful pregnancy, takes place. This work was supported by the Consejería de Economía, Innovación y Ciencia, Junta de Andalucía (Grant CTS-6183, Proyectos de Investigación de Excelencia 2010 to C.R.-R.) and the Instituto de Salud Carlos III, Ministerio de Economía y Competitividad, Spain (Grants PS09/00339 and PI12/01085 to E.G.O.). E.L.-D. was supported by fellowships from the Ministerio de Educación y Ciencia, Spain and the University of Granada. The authors have no conflict of interest. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Single-visit endodontic treatment of mature teeth with chronic apical abscesses using mineral trioxide aggregate cement: a randomized clinical trial.

PubMed

Alsulaimani, Reem Siraj

2016-08-23

Mature teeth with chronic apical abscesses characterized by intermittent discharge of pus through an associated sinus tract. This communication between oral mucosa and periapical inflammation is challenging for the sealing ability of root canal obturation material. Therefore, the study aim was to compare the outcomes of endodontic treatment using mineral trioxide aggregate (MTA) cement to the conventional gutta-percha cone and root canal sealer as an obturation material in mature teeth with chronic apical abscesses. Mature teeth with chronic apical abscesses referred to our clinic for root canal treatment between 2010 and 2012 were treated in a single visit and distributed among treatment (T) and control (C) groups using a predetermined randomization block (TCTC). After chemo-mechanical preparation, teeth in group T received MTA cement mixed in a 0.26 water to powder ratio, and teeth group C received gutta-percha and root canal sealer using the warm vertical technique. The treatment outcomes were defined as obturation length, periapical healing, resorption of extruded material, and survival rate at least 2.5 years after treatment. Three endodontists blinded to the type of obturation material documented treatment outcomes. Statistical analysis at P < 0.05 was conducted to measure difference between the groups. Thirty-six teeth were treated between 2010 and 2012, and 32 teeth were evaluated in 2015. Complete periapical healing was observed in 87.5 % of MTA-treated teeth and 75.0 % of gutta-percha-treated teeth. Adequate obturation length was reported in 50.0 % of MTA-treated and 37.5 % of gutta-percha-treated teeth. Complete resorption of extruded material was evident in 83.3 % MTA-treated teeth and 100.0 % gutta-percha-treated teeth. The survival rate of MTA-treated teeth was 100 % at 3, and 5 years, while the survival rate of gutta-percha-treated teeth was 83.3 % at 3, and 5 years. There was no significant difference between the groups in term of periapical healing, survival rate, obturation length, or resorption of extruded material. The outcomes of single-visit endodontic treatment of mature teeth with chronic apical abscesses using MTA cement were better, but not statistically significant, compared to conventional treatment. ISRCTN15285974 . Registered retrospectively 23 June 2015.

[Dynamic analysis of the rigid fixed bridge and related tissue after intrusion of abutment with micro screw implant].

PubMed

Zhu, Lin; Xu, Pei-cheng; Lu, Liu-lei

2013-08-01

To study the variety of mechanical behavior of fixed bridge after abutments being intruded by micro screw implant and to provide theoretical principles for clinical practice of teeth preparation after intrusion of abutments under dynamic loads. Two-dimensional images of maxilla, teeth and supporting tissues of healthy people were scanned by spiral CT and were synthesized by Mimics10.01, Ansys13.0, etc. The three-dimensional finite element mathematical model of rigid fixed bridge repairing on double end of maxillary molar was developed. Under the condition of 10% simulative abutment alveolar absorption, vertical and oblique dynamic forces were applied in a circle of mastication(0.875 s) to build mathematical model after the abutment had been intruded for 0.5, 1.0, 1.5 and 2.0 mm. Stress variety of prosthesis, teeth, periodontal ligaments and supporting tissues were compared before and after intrusion of abutments. Stress variety of the prosthesis occurred, which had close relationship with the structure of prosthesis and teeth, the areas of periodontal ligaments increased, stress on the whole decreased along with the increase of the length of intrusion. With time accumulating, the stress value in prosthesis, teeth, periodontal ligaments and supporting tissues increased gradually and loads in oblique direction induced peak value stress in a masticatory cycle. Some residual stress left after unloading. By preparing the fixed bridge after abutment intrusion by micro screw implant, the service life of abutment and fixed bridge prosthesis can be reduced. The abutment and its related tissue have time-dependent mechanical behaviors during one mastication. The influence of oblique force on stress was greater than vertical force. There is some residual stress left after one mastication period. With the increase of the intrusion on abutment, residual stress reduced.

Shrinkage stress compensation in composite-restored teeth: relaxation or hygroscopic expansion?

PubMed

Meriwether, Laurel A; Blen, Bernard J; Benson, Jarred H; Hatch, Robert H; Tantbirojn, Daranee; Versluis, Antheunis

2013-05-01

Polymerization of composite restorations causes shrinkage, which deforms and thus stresses restored teeth. This shrinkage deformation, however, has been shown to decrease over time. The objective was to investigate whether this reduction was caused by hygroscopic expansion or stress relaxation of the composite/tooth complex. Extracted molars were mounted in rigid stainless steel rings with four spherical reference areas. Twelve molars were prepared with large mesioocclusodistal slots, etched, bonded, and restored with a composite material (Filtek Supreme, 3M ESPE) in two horizontal layers. Ten intact molars were the controls. The teeth were stored either in deionized water or silicone oil. They were scanned after preparation (baseline), restoration (0-week), and after 1, 2, and 4 weeks storage. Scanned tooth surfaces were aligned with the baseline using the unchanged reference areas. Cuspal flexure was calculated from lingual and buccal surface deformation. To verify that the restorations had remained bonded, dye penetration at the interfaces was assessed using basic fuchsin dye. Statistical assessment was done by ANOVA followed by Student-Newman-Keuls post hoc test (p=0.05). Substantial cuspal contraction was found for restored teeth after the composite was cured (13-14 μm cuspal flexure). After 4 weeks cuspal contraction decreased significantly for restored teeth stored in water (7.3 ± 3.2) but not for those stored in silicone oil (11.4 ± 5.0). Dye penetration of the occlusal interface was minimal in both groups (106 ± 87 and 21 ± 28 μm in water and silicone oil, respectively). The results suggest that hygroscopic expansion was the main mechanism for shrinkage stress compensation. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Vertical dimensional stability and rigidity of occlusal registration materials.

PubMed

Walker, Mary P; Wu, Edis; Heckman, M Elizabeth; Alderman, Nicholas

2009-01-01

Dimensionally accurate occlusal registration records are essential for restorative dentistry; moreover, since records are not used immediately or may be used more than once, the registration material should exhibit accuracy over time (a concept known as dimensional stability). It has been speculated that materials with increased hardness or rigidity should produce more accurate registration records due to an increased resistance to distortion. This study compared the rigidity and associated dimensional accuracy of a recently marketed bisacrylic occlusal registration material and a vinyl polysiloxane (VPS). Maxillary and mandibular typodont arches were mounted on a plasterless articulator from which teeth No. 3, 13, and 15 had been removed to simulate edentulous spaces. After preparing teeth No. 2, 4, 12, and 14 as bridge abutments, the remaining teeth were equilibrated selectively to produce even anterior contact. Four digital photographs were taken to make vertical interarch measurements at four locations (teeth No. 3, 7, 10, and 14). Following initial photos (controls), 10 interocclusal records were made using each registration material, with material placed only in the segments in which teeth were prepared. The records were used for mounting the maxillary arch against the mandibular arch after 48, 72, and 120 hours. There were significant effects on vertical dimensional change related to arch location, material, and mounting time. Both materials demonstrated significantly larger posterior vertical openings than anterior vertical openings, while the bisacrylate produced a larger posterior opening than VPS at 48 and 72 hours and a larger anterior opening at all mounting times. There also was a significant difference in hardness/rigidity due to material and measurement time; at all measurement times, bisacrylate exhibited a significantly higher hardness number.

Sterilization of root canal spaces using an Nd:YAG laser, in vitro

NASA Astrophysics Data System (ADS)

Goodis, Harold E.; White, Joel M.; Yee, Barbara; Marshall, Sally J.; Marshall, Grayson W.

1995-05-01

A smear layer is created during the cleaning and shaping of root canal systems. The Nd:YAG laser has been shown to be effective in removing that smear layer and any tissue remnants from prepared root canal systems suggesting that it may aid in root canal sterilization without detrimental thermal effects to adjacent tissues. The root canal system of 72 single-rooted teeth was conventionally prepared and sterilized using gamma radiation. The teeth were divided into three groups of 24 each, 8 of which were inoculated only with sterile broth and remained as negative controls. Sixteen teeth of each group were inoculated with one of three organisms of 106 to 1010 CFU/(mu) l: B subtilis (BS), E. coli (EC) and S. marcescens (SM) (10 (mu) l). Eight in each group were not treated further and served as positive controls. Sixteen test teeth were treated with the laser three times using each exposure parameter: 1 W, 10 Hz pulses per second (pps); 2 W, 20 Hz; and 3 W, 30 Hz inserted to the radiographic apex. Laser exposures were completed while withdrawing the fiber from the root canal system. At completion of laser exposure, all teeth were cultured, using sterile paper points and plated on brain heat infusion agar. Three cultures were taken for each tooth, the plates incubated for 72 hours, and read for the presence of growth of colony-forming units. The laser was able to reduce the number of organisms placed in root canal systems, and suggests that the laser may be used in root canal therapy for bacterial reduction and cleaning of the root canal space.

Presence of Metallic Microfragments on Dentinal Walls and Instrument Defects following Root Canal Preparation.

PubMed

Solda, Caroline; Langaro, Marina C; Machado, Alessandra N; Vanni, José R; de A Decurcio, Daniel; Silva, Julio A; Estrela, Carlos; Barletta, Fernando B

2017-04-01

To determine the presence of metallic microfragments and their elemental composition in the dentinal walls of root canals following preparation using different endodontic instruments and to assess the active cutting edges of instruments with regard to structural defects. A total of 108 molar teeth were selected and prepared using different endodontic instruments. Teeth were randomly divided into nine groups of 12 teeth each, according to the instruments employed: Manual systems -K-FlexoFile, K-File, and Hedstroem; rotary systems - ProTaper Next, Mtwo, BioRaCe; and reciprocating systems - Reciproc, Unicone, and WaveOne. Both root canals and instruments were assessed using scanning electron microscopy, and the elemental composition of metallic microfragments was determined using energy-dispersive X-ray spectroscopy. Metallic microfragments were found in the groups prepared with both manual and reciprocating instruments, with no statistically significant differences between groups, thirds, or presence of metallic microfragments (p ≥ 0.05). Moreover, all groups presented structural defects in both new and used instruments; however, rotary instruments (ProTaper Next, Mtwo 702, BioRaCe) were the ones with the lowest number of defects, at statistically significant differences in comparison with other instruments (p < 0.05). The presence of metallic microfragments on dentinal walls following root canal preparation was associated with manual and reciprocating instrumentation. Furthermore, rotary instruments were the ones with the lowest number of defects. Considering the outcomes measured in this study, rotary instruments performed better than the other two groups, as they were associated with the lowest number of metallic microfragments and structural defects. During root canal preparation, operative procedures may induce changes to the root canal shape, as well as the release of metallic fragments resulting from the action of instruments on dentinal walls. Therefore, it is important to determine, among the different techniques used for this purpose, which ones are least susceptible to this occurrence.

A comparative study of shear bond strength of orthodontic bracket after acid-etched and Er:YAG treatment on enamel surface

NASA Astrophysics Data System (ADS)

Leão, Juliana C.; Mota, Cláudia C. B. O.; Cassimiro-silva, Patricia F.; Gomes, Anderson S. L.

2016-02-01

This study aimed to evaluate the shear bond strength (SBS) of teeth prepared for orthodontic bracket bonding with 37% phosphoric acid and Er:YAG laser. Forty bovine incisors were divided into two groups. In Group I, the teeth were conditioned with 37% phosphoric acid and brackets were bonded with Transbond XT; in Group II, the teeth were irradiated with Er:YAG and bonding with Transbond XT. After SBS test, the adhesive remnant index was determined. Adhesion to dental hard tissues after Er:YAG laser etching was inferior to that obtained after acid etching but exceeded what is believed to be clinically sufficient strength, and therefore can be used in patients.

Oxygen isotope analysis of shark teeth phosphates from Bartonian (Eocene) deposits in Mangyshlak peninsula, Kazakhstan

NASA Astrophysics Data System (ADS)

Pelc, Andrzej; Hałas, Stanisław; Niedźwiedzki, Robert

2011-01-01

We report the results of high-precision (±0.05‰) oxygen isotope analysis of phosphates in 6 teeth of fossil sharks from the Mangyshlak peninsula. This precision was achieved by the offline preparation of CO2 which was then analyzed on a dual-inlet and triple-collector IRMS. The teeth samples were separated from Middle- and Late Bartonian sediments cropping out in two locations, Usak and Kuilus. Seawater temperatures calculated from the δ18O data vary from 23-41°C. However, these temperatures are probably overestimated due to freshwater inflow. The data point at higher temperature in the Late Bartonian than in the Middle Bartonian and suggest differences in the depth habitats of the shark species studied.

[Computer aided design and manufacture of the porcelain fused to metal crown].

PubMed

Nie, Xin; Cheng, Xiaosheng; Dai, Ning; Yu, Qing; Hao, Guodong; Sun, Quanping

2009-04-01

In order to satisfy the current demand for fast and high-quality prosthodontics, we have carried out a research in the fabrication process of the porcelain fused to metal crown on molar with CAD/CAM technology. Firstly, we get the data of the surface mesh on preparation teeth through a 3D-optical grating measuring system. Then, we reconstruct the 3D-model crown with the computer-aided design software which was developed by ourselves. Finally, with the 3D-model data, we produce a metallic crown on a high-speed CNC carving machine. The result has proved that the metallic crown can match the preparation teeth ideally. The fabrication process is reliable and efficient, and the restoration is precise and steady in quality.

[Anterior bridges with the IPS-Empress-2 System after alveolar ridge augmentation. A case report].

PubMed

Zawta, C; Bernhard, M

2000-01-01

The success of a prosthesis is judged according to optimal function, good chewing comfort, adequate phonetics and white and pink esthetics. The aim of a treatment is to approach the perfection of nature. For anterior bridgework, the all-ceramic System IPS Empress 2 offers light transmission and reflection comparable to that of natural teeth, provided that the pink esthetics are optimised in the preprosthetic phase. The provision of an anterior bridge in the IPS Empress 2-system is presented here in the form of a case report. After extraction of the anterior teeth, a ridge augmentation including preparation of the pontic bed was carried out. The type of post and core, preparation and cementation are important parameters for the success of all-ceramic restorations.

Complications of misdiagnosis of maxillary canine ectopic eruption.

PubMed

Garib, Daniela Gamba; Janson, Guilherme; Baldo, Taiana de Oliveira; dos Santos, Patrícia Bittencourt Dutra

2012-08-01

Ectopic eruption of maxillary canines can be associated with root resorption of adjacent teeth. This case report describes and discusses an interesting case of a 15-year-old girl with a Class III malocclusion and an impacted maxillary canine. Because of the unfavorable position of the ectopic canine and the severe root resorption of the maxillary left central and lateral incisors, the treatment options included extraction of the maxillary permanent canines. The mandibular first premolars were extracted to compensate for the Class III malocclusion. A panoramic radiograph taken earlier in the mixed dentition already indicated a possible eruption disturbance of the maxillary left permanent canine. The importance of early diagnosis of maxillary canine ectopic eruption is highlighted in this case report. The early identification of radiographic signs of an ectopic pathway of eruption should be followed by deciduous canine extraction to prevent canine retention and maxillary incisor root resorption. Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Conventional Complete Denture in Patients with Ectodermal Dysplasia

PubMed Central

Vilanova, Larissa Soares Reis; Sánchez-Ayala, Alfonso; Ribeiro, Giselle Rodrigues; Campos, Camila Heitor; Farias-Neto, Arcelino

2015-01-01

Ectodermal dysplasia is described as heritable conditions that involve anomalies of structures derived from the ectoderm, including hypodontia. In the cases of edentulous young patients, who did not finish their craniofacial growth, treatment with conventional complete denture is a suitable alternative. The aim of this study was to report a case of mandibular edentulism treated with conventional complete denture in a thirteen-year-old patient diagnosed with hidrotic ectodermal dysplasia. Typical features, such as frontal bossing, depressed nasal bridge, protuberant lips, scarce hair, and brittle nails, were visualized during the extraoral examination. The intraoral inspection and radiographic analysis revealed oligodontia, dental malformation, and prolonged retention of deciduous teeth at maxilla and total edentulism at mandible. A conventional complete denture was planned and constructed following the same steps of technique as recommended in adults. Although this option is not a definitive treatment, the patient and his parents were satisfied with his improvement in chewing and speech, as well as with the aesthetic benefits. PMID:26425372

Direct effects of mitochondrial dysfunction on poor bone health in Leigh syndrome.

PubMed

Kato, Hiroki; Han, Xu; Yamaza, Haruyoshi; Masuda, Keiji; Hirofuji, Yuta; Sato, Hiroshi; Pham, Thanh Thi Mai; Taguchi, Tomoaki; Nonaka, Kazuaki

2017-11-04

Mitochondrial diseases are the result of aberrant mitochondrial function caused by mutations in either nuclear or mitochondrial DNA. Poor bone health has recently been suggested as a symptom of mitochondrial diseases; however, a direct link between decreased mitochondrial function and poor bone health in mitochondrial disease has not been demonstrated. In this study, stem cells from human exfoliated deciduous teeth (SHED) were isolated from a child with Leigh syndrome (LS), a mitochondrial disease, and the effects of decreased mitochondrial function on poor bone health were analyzed. Compared with control SHED, LS SHED displayed decreased osteoblastic differentiation and calcium mineralization. The intracellular and mitochondrial calcium levels were lower in LS SHED than in control SHED. Furthermore, the mitochondrial activity of LS SHED was decreased compared with control SHED both with and without osteoblastic differentiation. Our results indicate that decreased osteoblast differentiation potential and osteoblast function contribute to poor bone health in mitochondrial diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

Histopathologic changes in dental pulp of teeth with chronic periodontitis.

PubMed

Aguiar, Telma R; Tristao, Gilson C; Mandarino, Denize; Zarranz, Laila; Ferreira, Vinicius F; Barboza, Eliane P

2014-05-01

The aim of this study was to evaluate the histopathologic changes in dental pulp of teeth with chronic advanced periodontitis. In 22 patients, 30 teeth were selected for inclusion. Patients had received no periodontal treatment. No teeth had caries, abrasion, attrition, erosion, trauma, or restoration. Radiographically, all teeth showed bone-support destruction to the apex. Thermal and cavity tests were used to evaluate pulp vitality. After tooth extractions, crowns were separated from roots at the cementoenamel junction. Both the crowns and the roots were prepared for histopathologic analyses. Radicular pulp was analyzed considering both coronal and apical halves. In 100 percent of the cases, coronal pulp exhibited soft connective tissue. In the coronal half of radicular pulp, soft connective tissue was present in 60 percent of the cases, fibrosis in 30 percent, and fibrosis associated with dystrophic calcification in 10 percent. In the apical half of radicular pulp, 6.6 percent of the cases demonstrated fibrosis; 23 percent exhibited fibrosis associated with pulp atrophy and secondary dentin; and 63.3 percent showed fibrosis, pulp atrophy, secondary dentin, and diffuse calcification. Radicular pulp of teeth with chronic periodontitis presents characteristics compatible with pulp changes resulting from pulp aging. In such cases, endodontic treatment is not indicated to enhance periodontal treatment results.

Involvement of human decidual cell-expressed tissue factor in uterine hemostasis and abruption

PubMed Central

Lockwood, C.J.; Paidas, M.; Murk, W.K.; Kayisli, U.A.; Gopinath, A.; Krikun, G.; Huang, S.J.; Schatz, F.

2009-01-01

Vascular injury increases access and binding of plasma-derived factor VII to perivascular cell membrane-bound tissue factor (TF). The resulting TF/VIIa complex promotes hemostasis by cleaving pro-thrombin to thrombin leading to the fibrin clot. In human pregnancy, decidual cell-expressed TF prevents decidual hemorrhage (abruption). During placentation, trophoblasts remodel decidual spiral arteries into high conductance vessels. Shallow trophoblast invasion impedes decidual vascular conversion, producing an inadequate uteroplacental blood flow that elicits abruption-related placental ischemia. Thrombin induces several biological effects via cell surface protease activated receptors. In first trimester human DCs thrombin increases synthesis of sFlt-1, which elicits placental ischemia by impeding angiogenesis-related decidual vascular remodeling. During pregnacy, the fibrillar collagen-rich amnion and choriodecidua extracellular matrix (ECM) provides greater than additive tensile strength and structural integrity. Thrombin acts as an autocrine/paracrine mediator that degrades these ECMs by augmenting decidual cell expression of: 1) matrix metalloproteinases and 2) interleukin-8, a key mediator of abruption-associated decidual infiltration of neutrophils, which express several ECM degrading proteases. Our recent observations that: 1) among the cell types at the maternal fetal interface at term TF expression is highest in decidual cells indicates that this TF meets the hemostatic demands of labor and delivery; 2) TF expression in cultured term decidual cells is enhanced by progestin and thrombin suggest that maintenance of elevated circulating progesterone at term provides hemostatic protection, whereas abruption-generated thrombin can act in autocrine/paracrine fashion on DCs to promote hemostasis via enhanced TF expression. PMID:19720393

Effects of various cone-beam computed tomography settings on the detection of recurrent caries under restorations in extracted primary teeth.

PubMed

Kamburoğlu, Kıvanç; Sönmez, Gül; Berktaş, Zeynep Serap; Kurt, Hakan; Özen, Doĝukan

2017-06-01

The aim of this study was to assess the ex vivo diagnostic ability of 9 different cone-beam computed tomography (CBCT) settings in the detection of recurrent caries under amalgam restorations in primary teeth. Fifty-two primary teeth were used. Twenty-six teeth had dentine caries and 26 teeth did not have dentine caries. Black class II cavities were prepared and restored with amalgam. In the 26 carious teeth, recurrent caries were left under restorations. The other 26 intact teeth that did not have caries served as controls. Teeth were imaged using a 100×90-mm field of view and a 0.2-mm voxel size with 9 different CBCT settings. Four observers assessed the images using a 5-point scale. Kappa values were calculated to assess observer agreement. CBCT settings were compared with the gold standard using a receiver operating characteristic analysis. The area under the curve (AUC) values for each setting were compared using the chi-square test, with a significance level of α=.05. Intraobserver kappa values ranged from 0.366 to 0.664 for observer 1, from 0.311 to 0.447 for observer 2, from 0.597 to 1.000 for observer 3, and from 0.869 to 1 for observer 4. Furthermore, interobserver kappa values among the observers ranged from 0.133 to 0.814 for the first reading and from 0.197 to 0.805 for the second reading. The highest AUC values were found for setting 5 (0.5916) and setting 3 (0.5886), and were not found to be statistically significant ( P >.05). Variations in tube voltage and tube current did not affect the detection of recurrent caries under amalgam restorations in primary teeth.

Insect management in deciduous orchard ecosystems: Habitat manipulation

NASA Astrophysics Data System (ADS)

Tedders, W. L.

1983-01-01

Current literature pertaining to habitat manipulation of deciduous fruit and nut orchards for pest control is reviewed. The hypothesis of pesticide-induced pest problems in deciduous orchards as well as the changing pest population dynamics of deciduous orchards is discussed An experimental habitat manipulation program for pecans, utilizing vetch cover crops to enhance lady beetle populations for pecan aphid control is presented

Phosphatidic acid induces decidualization by stimulating Akt-PP2A binding in human endometrial stromal cells.

PubMed

Lee, So Young; Lee, Yun Young; Choi, Joong Sub; Yoon, Mee-Sup; Han, Joong-Soo

2016-11-01

Decidualization of human endometrial stromal cells (hESCs) is crucial for successful uterine implantation and maintaining pregnancy. We previously reported that phospholipase D1 (PLD1) is required for cAMP-induced decidualization of hESCs. However, the mechanism by which phosphatidic acid (PA), the product of PLD1 action, might regulate decidualization is not known. We confirmed that PA induced decidualization of hESCs by observing morphological changes and measuring increased levels of decidualization markers such as IGFBP1 and prolactin transcripts (P < 0.05). Treatment with PA reduced phosphorylation of Akt and consequently that of FoxO1, which led to the increased IGFBP1 and prolactin mRNA levels (P < 0.05). Conversely, PLD1 knockdown rescued Akt phosphorylation. Binding of PP2A and Akt increased in response to cAMP or PA, suggesting that their binding is directly responsible for the inactivation of Akt during decidualization. Consistent with this observation, treatment with okadaic acid, a PP2A inhibitor, also inhibited cAMP-induced decidualization by blocking Akt dephosphorylation. © 2016 The Authors. The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.

Post retention: the effect of sequence of post-space preparation, cementation time, and different sealers.

PubMed

Boone, K J; Murchison, D F; Schindler, W G; Walker, W A

2001-12-01

Many endodontic sealers contain constituents that have been shown to inhibit the polymerization of resin cements. This may be important when prefabricated posts are cemented at the same appointment as root canal obturation. This study evaluated the effects of cementing posts with a resin cement immediately or at a delayed time period after obturation using Roth's 801 Elite Grade or AH26 sealer cements. The contribution of mechanical post-space preparation was also assessed as a critical variable. One hundred twenty extracted canines were randomly divided into eight experimental groups. The variables evaluated were the order of post preparation (either before or after obturation), the type of sealer used, and the time of post cementation. All teeth received a stainless steel #6 Parapost XP cemented with a resin cement, Panavia 21. Each experimental group underwent tensile testing for retention using an Instron universal testing machine. For both sealers posts cemented in teeth in which the canal was obturated before post-space preparation and thus had sealer-contaminated dentin removed by the space preparation procedure had significantly higher retentive values than those obturated after post-space preparation in which contaminated dentin might remain. Sealer used and time of cementation had no specific effect on retention. Achieving a clean, "freshened" dentinal surface during mechanical post-space preparation seems to be a critical variable for post retention when a resin cement is used.

Transverse effect of Haas and Hyrax appliances on the upper dental arch in patients with unilateral complete cleft lip and palate: a comparative study.

PubMed

Façanha, Anna Júlia de Oliveira; Lara, Tulio Silva; Garib, Daniela Gamba; da Silva Filho, Omar Gabriel

2014-01-01

The aim of the present study was to evaluate the transverse effect of rapid maxillary expansion in patients with unilateral complete cleft lip and palate while comparing the Haas and Hyrax appliances. The sample consisted of 48 patients divided into two groups: Group I = 25 patients treated with modified Haas appliance (mean age: 10 years and 8 months); and Group II = 23 patients treated with Hyrax appliance (mean age: 10 years and 6 months). Cast models were taken during pre-expansion and after removal of the appliance, at the end of the retention period. The models were scanned with the aid of the 3 Shape R700 3D scanner. Initial and final transverse distances were measured at cusp tips and cervical-palatal points of maxillary teeth by using the Ortho Analyzer 3D software. The mean expansion obtained between cusp tips and between cervical-palatal points was, respectively: for inter-canine width, 4.80 mm and 4.35 mm with the Haas appliance and 5.91 mm and 5.91 mm with the Hyrax appliance; as for first deciduous molars or first deciduous premolars, the values obtained were 6.46 mm and 5.90 mm in the Haas group, and 7.11 mm and 6.65 mm in the Hyrax group; with regard to first molars, values were 6.11 mm and 5.24 mm in the Haas group, and 7.55 mm and 6.31 mm in the Hyrax group. Rapid maxillary expansion significantly increased the transverse dimensions of the upper dental arch in patients with cleft palate, with no significant differences between the Hass and Hyrax expanders.

Miocene fossil plants from Bukpyeong Formation of Bukpyeong Basin in Donghae City, Gangwon-do Province, Korea and their palaeoenvironmental implications

NASA Astrophysics Data System (ADS)

Jeong, Eun Kyoung; Kim, Hyun Joo; Uemura, Kazuhiko; Kim, Kyungsik

2016-04-01

The Tertiary sedimentary basins are distributed along the eastern coast of Korean Peninsula. The northernmost Bukpyeong Basin is located in Donghae City, Gangwon-do Province, Korea. The Bukpyeong Basin consists of Bukpyeong Formation and Dogyeongri Conglomerate in ascending order. The geologic age of Bukpyeong Formation has been suggested as from Early Miocene to Pliocene, In particular, Lee & Jacobs (2010) suggested the age of the Bukpyeong Formation as late Early Miocene to early Middle Miocene based on the fossils of rodent teeth. Sedimentary environment has been thought as mainly fresh water lake and/or swamp partly influenced by marine water. Lately, new outcrops of Bukpyeong Formation were exposed during the road construction and abundant fossil plants were yielded from the newly exposed outcrops. As a result of palaeobotanical studies 47 genera of 23 families have been found. This fossil plant assemblage is composed of gymnosperms and dicotyledons. Gymnosperms were Pinaceae (e.g., Pinus, Tsuga), Sciadopityaceae (e.g., Sciadopitys) and Cupressaceae with well-preserved Metasequoia cones. Dicotyledons were deciduous trees such as Betulaceae (e.g., Alnus, Carpinus) and Sapindaceae (e.g., Acer, Aesculus, Sapindus), and evergreen trees such as evergreen Fagaceae (e.g., Castanopsis, Cyclobalanopsis, Pasania) and Lauraceae (e.g., Cinnamomum, Machilus). In addition, fresh water plants such as Hemitrapa (Lytraceae) and Ceratophyllum (Ceratophyllaceae) were also found. The fossil plant assemblage of the Bukpyeong Formation supported the freshwater environment implied by previous studies. It can be suggested that the palaeoflora of Bukpyeong Formation was oak-laurel forest with broad-leaved evergreen and deciduous trees accompanying commonly by conifers of Pinaceae and Cupressaceae under warm-temperate climate.

Pre- and Postnatal Determinants of Deciduous Molar Hypomineralisation in 6-Year-Old Children. The Generation R Study

PubMed Central

Elfrink, Marlies E. C.; Moll, Henriette A.; Kiefte-de Jong, Jessica C.; Jaddoe, Vincent W. V.; Hofman, Albert; ten Cate, Jacob M.; Veerkamp, Jaap S. J.

2014-01-01

Background Deciduous Molar Hypomineralisation (DMH) and Molar Incisor Hypomineralisation (MIH) are common developmental disturbances in pediatric dentistry. Their occurrence is related. The same determinants as suggested for MIH are expected for DMH, though somewhat earlier in life. Perinatal medical problems may influence the prevalence of DMH but this has not been studied sufficiently. Objective This study aimed to identify possible determinants of DMH in a prospective cohort study among 6-year-old children. Study Design This study was embedded in the Generation R Study, a population-based prospective cohort study from fetal life until young adulthood. The the data were used to identify the determinants of DMH. Clinical photographs of clean, moist teeth were taken with an intra-oral camera in 6690 children (mean age 6.2 years; 49.9% girls). Data on possible determinants that had occurred during pregnancy and/or the child's first year of life were on the basis of manual standardized measurements (like length and weight) and questionnaires. Multivariate analyse with backward and forward selection was performed. Results A number of factors in the pre-, peri- and postnatal phase were found to be associated with DMH. After multivariate logistic regression analyses, Dutch ethnic background, low birth weight, maternal alcohol consumption during pregnancy, and fever episodes in the first year of the child's life were found to play a role in the development of DMH in 6-year-old children. Conclusion This study shows that Dutch ethnicity, low birth weight, alcohol consumption by the mother during pregnancy and any fever in the first year of the child's life are associated with DMH. Not only childhood factors but also prenatal lifestyle factors need to be taken into account when studying determinants for DMH. PMID:24988443

Dentoalveolar growth inhibition induced by bone denudation on palates: a study of two isolated cleft palates with asymmetric scar tissue distribution.

PubMed

Ishikawa, H; Iwasaki, H; Tsukada, H; Chu, S; Nakamura, S; Yamamoto, K

1999-09-01

This report presents two cases of isolated cleft palate with asymmetric distribution of postsurgical scar tissue determined by laser Doppler flowmetry. To determine the effect of mucoperiosteal denudation of the bone on maxillary alveolar growth, the analysis of dentoalveolar structures compared the affected side to the unaffected side of each case. Two Japanese girls with isolated cleft palates were examined. Both subjects had undergone pushback operations (a modified version of the procedure of Wardill) for palatal repair at 18 months of age. Palatal blood flow was examined by laser Doppler flowmetry when the girls were 12 years old to determine the extent of postsurgical scar tissue over the denuded bone. To analyze the maxillary dentoalveolar structures three dimensionally, the whole surface of the upper dental cast was measured and recorded by an optical measuring device when the girls were 7 years old. Analysis via flowmetry showed that the palatal scar tissue area was limited to the anterior tooth region on the right (unaffected) side but extended posteriorly to the premolar region on the left (affected) side in both subjects. The two girls had similar dentoalveolar structures, with the dental and alveolar arches deflected lingually at the deciduous molar area on the affected side. There were no differences in the buccolingual inclination of deciduous molars or in the vertical growth of the alveolar processes between the affected and unaffected sides. In both girls, bone denudation in the premolar region appeared to result in less than 3 mm of displacement of the teeth palatally, with no change in lingual inclination. Any effects of scar tissue on the vertical development of the alveolus were not substantiated.

Periodontal healing by periodontal ligament cell sheets in a teeth replantation model.

PubMed

Zhou, Yefang; Li, Yusheng; Mao, Ling; Peng, Hao

2012-02-01

Successful transplantation of avulsed teeth is to restore the attachment and regenerate the periodontal support. Different strategies have been applied in treatment from modification of teeth storage, antibiotic usage to peridontium tissue replacement. We developed a novel periodontal ligament cell-sheet delivery system to apply on delayed replanted teeth in promoting periodontal healing in a canine model. Autologous periodontal ligament (PDL) fibroblasts were isolated from extracted premolars of beagle dog. The cell-sheets were fabricated using normal culture dish after stimulation of extracellular matrix formation. Teeth were surgically extracted and attached soft tissues were removed. After root canal treatment, the root of teeth were wrapped by the PDL cell-sheets and replanted back to prior socket accordingly whilst teeth without cell sheets as a control. Eight weeks after surgery, the animals were sacrificed and decalcified specimens were prepared. Regeneration of periodontal tissue was evaluated through histology assay. Multi-layered PDL cell-sheet could be attached on tooth root and most cells on sheet-tooth constructs were viable before replantation. Minimum clinical signs of inflammation were observed in experiment. PDL cell-sheets group show significant higher occurrence of favourable healing (88.4%) than control group with low healing (5.3%). Periodontal ligament and cememtum tissue regeneration was observed in the experimental group, and the regenerated tissues showed high collagen type III, type I and fibronectin expression. The periodontal ligament cell-sheets fabricated through normal cell culture dish has a potential for regeneration of periodontal ligament and may become a novel therapy for avulsed teeth replantation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Fracture resistance of pulpless teeth restored with post-cores and crowns.

PubMed

Hayashi, Mikako; Takahashi, Yutaka; Imazato, Satoshi; Ebisu, Shigeyuki

2006-05-01

The present study was designed to test the null hypothesis that there is no difference in the fracture resistance of pulpless teeth restored with different types of post-core systems and full coverage crowns. Extracted human upper premolars were restored with a fiber post, prefabricated metallic post or cast metallic post-core. Teeth with full crown preparations without post-core restorations served as a control. All teeth were restored with full coverage crowns. A 90-degree vertical or 45-degree oblique load was applied to the restored teeth with a crosshead speed of 0.5 mm/min, and the fracture loads and mode of fracture were recorded. Under the condition of vertical loading, the fracture load of teeth restored with the cast metallic post-cores was greatest among the groups (two-factor factorial ANOVA and Scheffe's F test, P<0.05). All fractures in teeth restored with all types of post-core systems propagated in the middle portions of roots, including the apices of the posts. Under the condition of oblique loading, the fracture load of teeth restored with pre-fabricated metallic posts was significantly smaller than that in other groups. Two-thirds of fractures in the fiber post group propagated within the cervical area, while most fractures in other groups extended beyond the middle of the roots. From the results of the present investigations, it was concluded that under the conditions of vertical and oblique loadings, the combination of a fiber post and composite resin core with a full cast crown is most protective of the remaining tooth structure.

Regenerating Longleaf Pine on Hydric Soils: Short- and Long-term Effects on Native Ground-Layer Vegetation

DTIC Science & Technology

2009-06-16

trees required for red - cockaded woodpecker foraging. On landscapes where foraging habitat is extremely limited, site preparation choices that...inkberry) and Persea borbonia ( red bay) are evergreen with somewhat waxy green leaves and the potential to grow taller than 3 m. Of the deciduous taxa...shrub abundance in a pine savanna. Ecology 87:1331-1337. U.S. Fish and Wildlife Service. 2004. Red -cockaded woodpecker recovery plan. Washington , DC

Divergent Hydraulic Safety Strategies in Three Co-occurring Anacardiaceae Tree Species in a Chinese Savanna.

PubMed

Zhang, Shu-Bin; Zhang, Jiao-Lin; Cao, Kun-Fang

2016-01-01

Vulnerability segmentation, the condition under which plant leaves are more vulnerable to drought-induced cavitation than stems, may act as a "safety valve" to protect stems from hydraulic failure. Evergreen, winter-deciduous, and drought-deciduous tree species co-occur in tropical savannas, but there have been no direct studies on the role of vulnerability segmentation and stomatal regulation in maintaining hydraulic safety in trees with these three leaf phenologies. To this end, we selected three Anacardiaceae tree species co-occurring in a Chinese savanna, evergreen Pistacia weinmanniifolia , drought-deciduous Terminthia paniculata , and winter-deciduous Lannea coromandelica , to study inter-species differentiation in leaf and stem hydraulic safety. We found that the two deciduous species had significantly higher sapwood-specific hydraulic conductivity and leaf-specific hydraulic conductance than the evergreen species. Moreover, two deciduous species were more vulnerable to stem cavitation than the evergreen species, although both drought-deciduous species and evergreen species had drought-resistance leaves. The evergreen species maintained a wide hydraulic safety margin (HSM) in stems and leaves; which was achieved by embolism resistance of both stems and leaves and isohydric stomatal control. Both deciduous species had limited HSMs in stems and leaves, being isohydric in the winter-deciduous species and anisohydric in drought-deciduous species. The difference in water potential at 50% loss of hydraulic conductivity between the leaves and the terminal stems (P50 leaf-stem ) was positive in P. weinmanniifolia and L. coromandelica , whereas, T. paniculata exhibited a lack of vulnerability segmentation. In addition, differences in hydraulic architecture were found to be closely related to other structural traits, i.e., leaf mass per area, wood density, and sapwood anatomy. Overall, the winter-deciduous species exhibits a drought-avoidance strategy that maintains the hydraulic safety of the more carbon-costly stems by sacrificing cheaper and more vulnerable leaves, while the evergreen species exhibits a hydraulic strategy of drought tolerance with strong stomatal regulation. In contrast, the drought-deciduous species lacks vulnerability segmentation and sheds leaves at the expense of top shoots during peak drought. This study demonstrates that even sympatric tree species that differ in leaf phenology can exhibit divergent adaptive hydraulic safety strategies.

Ceramic and polymeric dental onlays evaluated by photo-elasticity, optical coherence tomography, and micro-computed tomography

NASA Astrophysics Data System (ADS)

Sinescu, Cosmin; Negrutiu, Meda; Topala, Florin; Ionita, Ciprian; Negru, Radu; Fabriky, Mihai; Marcauteanu, Corina; Bradu, Adrian; Dobre, George; Marsavina, Liviu; Rominu, Mihai; Podoleanu, Adrian

2011-10-01

Dental onlays are restorations used to repair rear teeth that have a mild to moderate amount of decay. They can also be used to restore teeth that are cracked or fractured if the damage is not severe enough to require a dental crown. The use of onlays requires less tooth reduction than does the use of metal fillings. This allows dentists to conserve more of a patient's natural tooth structure in the treatment process. The aims of this study are to evaluate the biomechanical comportment of the dental onlays, by using the 3D photo elasticity method and to investigate the integrity of the structures and their fitting to the dental support. For this optical coherence tomography and micro-computed tomography were employed. Both methods were used to investigate 37 dental onlays, 17 integral polymeric and 20 integral ceramic. The results permit to observe materials defects inside the ceramic or polymeric onlays situate in the biomechanically tensioned areas that could lead to fracture of the prosthetic structure. Marginal fitting problems of the onlays related to the teeth preparations were presented in order to observe the possibility of secondary cavities. The resulted images from the optical coherence tomography were verified by the micro-computed tomography. In conclusion, the optical coherence tomography can be used as a clinical method in order to evaluate the integrity of the dental ceramic and polymeric onlays and to investigate the quality of the marginal fitting to the teeth preparations.

Effect of Metal Artifacts on Detection of Vertical Root Fractures Using Two Cone Beam Computed Tomography Systems.

PubMed

Safi, Yaser; Aghdasi, Mohammad Mehdi; Ezoddini-Ardakani, Fatemeh; Beiraghi, Samira; Vasegh, Zahra

2015-01-01

Vertical root fracture (VRF) is common in endodontically treated teeth. Conventional and digital radiographies have limitations for detection of VRFs. Cone-beam computed tomography (CBCT) offers greater detection accuracy of VRFs in comparison with conventional radiography. This study compared the effects of metal artifacts on detection of VRFs by using two CBCT systems. Eighty extracted premolars were selected and sectioned at the level of the cemento enamel junction (CEJ). After preparation, root canals were filled with gutta-percha. Subsequently, two thirds of the root fillings were removed for post space preparation and a custom-made post was cemented into each canal. The teeth were randomly divided into two groups (n=40). In the test group, root fracture was created with Instron universal testing machine. The control teeth remained intact. CBCT scans of all teeth were obtained with either New Tom VGI or Soredex Scanora 3D. Three observers analyzed the images for detection of VRF. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for VRF detection and percentage of probable cases were calculated for each imaging system and compared using non-parametric tests considering the non-normal distribution of data. The inter-observer reproducibility was calculated using the weighted kappa coefficient. There were no statistically significant differences in sensitivity, specificity, PPV and NPV between the two CBCT systems. The effect of metal artifacts on VRF detection was not significantly different between the two CBCT systems.

Quantitative evaluation of apical extrusion of intracanal bacteria using rotary ProTaper, K3XF, twisted and hand K-file system: An ex vivo study.

PubMed

Ghogre, Priyanka; Chourasia, Hemant Ramesh; Agarwal, Manish; Singh, M P; Gurav, Sandeep; Ghogre, Rahul

2015-01-01

The aim of this study was to evaluate the number of intracanal bacteria extruded apically during root canal preparation using rotary ProTaper, K3XF, twisted, and hand K-file system. Seventy extracted single-rooted human mandibular premolar teeth were used. Access cavities were prepared and the teeth were mounted in glass vials. Root canals were then contaminated with a pure culture of Enterococcus faecalis (ATCC 29212) and incubated at 37°C for 24 h. The contaminated roots were divided into four experimental groups of 15 teeth each and one control group of 10 teeth. Group 1: ProTaper; Group 2: K3XF; Group 3: Twisted file; Group 4: Hand K-file; Group 5: Control group. Bacteria extruded from the apical foramen during instrumentation were collected into vials. The microbiological samples were incubated in culture media for 24 h. Colonies of bacteria were counted and the results were given as number of colony-forming units (CFU)/ml. The obtained data were analyzed using the Kruskal-Wallis one-way analysis of variance and Mann-Whitney U-tests. There was a significant difference between the rotary and hand instrumentation system related to the apically extruded intracanal bacteria. Both the rotary and hand instrumentation systems extruded intracanal bacteria through the apical foramen. K3XF file system showed least bacterial extrusion amongst all instrumentation groups.

An M1-like Macrophage Polarization in Decidual Tissue during Spontaneous Preterm Labor That Is Attenuated by Rosiglitazone Treatment.

PubMed

Xu, Yi; Romero, Roberto; Miller, Derek; Kadam, Leena; Mial, Tara N; Plazyo, Olesya; Garcia-Flores, Valeria; Hassan, Sonia S; Xu, Zhonghui; Tarca, Adi L; Drewlo, Sascha; Gomez-Lopez, Nardhy

2016-03-15

Decidual macrophages are implicated in the local inflammatory response that accompanies spontaneous preterm labor/birth; however, their role is poorly understood. We hypothesized that decidual macrophages undergo a proinflammatory (M1) polarization during spontaneous preterm labor and that PPARγ activation via rosiglitazone (RSG) would attenuate the macrophage-mediated inflammatory response, preventing preterm birth. In this study, we show that: 1) decidual macrophages undergo an M1-like polarization during spontaneous term and preterm labor; 2) anti-inflammatory (M2)-like macrophages are more abundant than M1-like macrophages in decidual tissue; 3) decidual M2-like macrophages are reduced in preterm pregnancies compared with term pregnancies, regardless of the presence of labor; 4) decidual macrophages express high levels of TNF and IL-12 but low levels of peroxisome proliferator-activated receptor γ (PPARγ) during spontaneous preterm labor; 5) decidual macrophages from women who underwent spontaneous preterm labor display plasticity by M1↔M2 polarization in vitro; 6) incubation with RSG reduces the expression of TNF and IL-12 in decidual macrophages from women who underwent spontaneous preterm labor; and 7) treatment with RSG reduces the rate of LPS-induced preterm birth and improves neonatal outcomes by reducing the systemic proinflammatory response and downregulating mRNA and protein expression of NF-κB, TNF, and IL-10 in decidual and myometrial macrophages in C57BL/6J mice. In summary, we demonstrated that decidual M1-like macrophages are associated with spontaneous preterm labor and that PPARγ activation via RSG can attenuate the macrophage-mediated proinflammatory response, preventing preterm birth and improving neonatal outcomes. These findings suggest that the PPARγ pathway is a new molecular target for future preventative strategies for spontaneous preterm labor/birth. Copyright © 2016 by The American Association of Immunologists, Inc.

[Fiber-reinforced composite in fixed prosthodontics].

PubMed

Pilo, R; Abu Rass, Z; Shmidt, A

2010-07-01

Fiber reinforced composite (FRC) is composed of resin matrix and fibers filler. Common types of fibers: polyethylene, carbon and glass. Fibers can be continuous and aligned, discontinuous and aligned, discontinuous and randomly oriented. The architecture of the fibers is unidirectional, woven or braided. The two main types are: dry fibers or impregnated. Inclusion of fibers to resin composite increased its average flexural strength in 100-200 MPa. FRC can be utilized by the dentist in direct approach (splinting, temporary winged bridge) or indirect approach (laboratory made fixed partial denture). Laboratory fixed partial denture (FPD) is made from FRC substructure and Hybrid/Microfill particulate composite veneer. Main indications: interim temporary FPD or FPD in cases of questionable abutment teeth, in aesthetic cases where All Ceram FPD is not feasible. Retention is attained by adhesive cementation to minimally prepared teeth or to conventionally prepared teeth; other options are inlay-onlay bridges or hybrid bridges. Contraindications are: poor hygiene, inability to control humidity, parafunction habits, and more than two pontics. Survival rate of FRC FPD over 5 years is 75%, lower compared to porcelain fused to metal FPD which is 95%. Main reasons for failure are: fracture of framework and delamination of the veneer. Part of the failures is repairable.

Roles of Estrogen Receptor-α and the Coactivator MED1 During Human Endometrial Decidualization

PubMed Central

Kaya Okur, Hatice S.; Das, Amrita; Taylor, Robert N.; Bagchi, Indrani C.

2016-01-01

The steroid hormones 17β-estradiol and progesterone are critical regulators of endometrial stromal cell differentiation, known as decidualization, which is a prerequisite for successful establishment of pregnancy. The present study using primary human endometrial stromal cells (HESCs) addressed the role of estrogen receptor-α (ESR1) in decidualization. Knockdown of ESR1 transcripts by RNA interference led to a marked reduction in decidualization of HESCs. Gene expression profiling at an early stage of decidualization indicated that ESR1 negatively regulates several cell cycle regulatory factors, thereby suppressing the proliferation of HESCs as these cells enter the differentiation program. ESR1 also controls the expression of WNT4, FOXO1, and progesterone receptor (PGR), well-known mediators of decidualization. Whereas ESR1 knockdown strongly inhibited the expression of FOXO1 and WNT4 transcripts within 24 hours of the initiation of decidualization, PGR expression remained unaffected at this early time point. Our study also revealed a major role of cAMP signaling in influencing the function of ESR1 during decidualization. Using a proteomic approach, we discovered that the cAMP-dependent protein kinase A (PKA) phosphorylates Mediator 1 (MED1), a subunit of the mediator coactivator complex, during HESC differentiation. Using immunoprecipitation, we demonstrated that PKA-phosphorylated MED1 interacts with ESR1. The PKA-dependent phosphorylation of MED1 was also correlated with its enhanced recruitment to estrogen-responsive elements in the WNT4 gene. Knockdown of MED1 transcripts impaired the expression of ESR1-induced WNT4 and FOXO1 transcripts and blocked decidualization. Based on these findings, we conclude that modulation of ESR1-MED1 interactions by cAMP signaling plays a critical role in human decidualization. PMID:26849466

Decidual activin: its role in the apoptotic process and its regulation by prolactin.

PubMed

Tessier, Christian; Prigent-Tessier, Anne; Bao, Lei; Telleria, Carlos M; Ferguson-Gottschall, Susan; Gibori, Gil B; Gu, Yan; Bowen-Shauver, Jennifer M; Horseman, Nelson D; Gibori, Geula

2003-05-01

Successful pregnancy requires profound differentiation and reorganization of the uterine tissues including, as pregnancy progresses, extensive apoptosis of decidual tissue to accommodate the developing conceptus. We have previously shown a positive correlation between expression of activin A and apoptosis in the decidua and have also shown that expression of activin A occurs at the time when prolactin (PRL) receptors disappear from decidual cells. The goals of this study were to examine whether activin A plays a role in decidual apoptosis and whether expression of activin A in the decidua is regulated by PRL and placental lactogens. Studies were carried out using primary rat decidual cells, a decidual cell line (GG-AD), and PRL null mice. Treatment of decidual cells with activin A significantly increased DNA degradation, caspase 3 activity, and caspase 3 mRNA expression. However, this effect was observed only in the absence of endogenous activin production by these cells. Addition of follistatin to decidual cells that were producing activin A decreased both caspase 3 activity and mRNA expression. Similarly, addition of activin-blocking antibodies to cultures of GG-AD cells, which also produce activin A, caused a reduction in both DNA degradation and caspase 3 activity. PRL and placental lactogens caused an inhibition of activin A mRNA expression in primary decidual cells. Even more convincingly, decidua of PRL null mice expressed abundant activin A at a time when no expression of this hormone is detected in wild-type mice and treatment of PRL null mice with PRL caused a profound inhibition of activin A mRNA expression. In summary, our investigations into the role and regulation of decidual activin have revealed that activin A can induce cell death in the decidua and that its expression is under tight regulation by PRL and placental lactogens.

Expression of NK cell receptors on decidual T cells in human pregnancy.

PubMed

Tilburgs, Tamara; van der Mast, Barbara J; Nagtzaam, Nicole M A; Roelen, Dave L; Scherjon, Sicco A; Claas, Frans H J

2009-06-01

Specific receptors enable NK cells to discriminate between cells with normal expression of MHC class I and cells that have low or absent expression of MHC class I molecules. In addition to NK cells, these receptors can be expressed on T cell subsets, mainly on CD8+ T cells but also on gammadeltaTCR+ T cells and CD4+ T cells. Although the function of NK cell receptor expression on T cells is not completely understood, various studies have shown that they are involved in down regulation of T cell receptor (TCR)-mediated activation and influence effector functions, like cytotoxicity and cytokine production. The aim of this study was to analyze expression of NK cell receptors on peripheral blood and decidual T cells during human pregnancy using flow cytometry. We demonstrate that a proportion of decidual T cells express HLA-C specific killer immunoglobulin-like receptors (KIRs). Furthermore, a small proportion of decidual T cells express the HLA-E specific CD94-NKG2A inhibitory and CD94-NKG2C activating receptors. Decidual KIR+ and CD94-NKG2+ T cells mainly display a CD3+CD4-CD8- phenotype. However, decidual tissue also contains higher percentages of KIR and CD94-NKG2 expressing CD4+ and CD8+ T cells compared to peripheral blood. So far, the functional capacities of decidual T cells expressing the NK cell receptors are unknown but NK cell receptor expression on decidual T cells may provide an alternative means by which decidual T cells distinguish self (maternal) cells from allogeneic fetal cells, and act to modulate the decidual immune response.

An M1-like macrophage polarization in decidual tissue during spontaneous preterm labor that is attenuated by rosiglitazone treatment1

PubMed Central

Kadam, Leena; Mial, Tara N.; Plazyo, Olesya; Garcia-Flores, Valeria; Hassan, Sonia S.; Xu, Zhonghui; Tarca, Adi L.; Drewlo, Sascha; Gomez-Lopez, Nardhy

2016-01-01

Macrophages are implicated in the local inflammatory response that accompanies spontaneous preterm labor/birth; however, their role is poorly understood. We hypothesized that decidual macrophages undergo an M1 polarization during spontaneous preterm labor and that PPARγ activation via rosiglitazone would attenuate the macrophage-mediated inflammatory response, preventing preterm birth. Herein, we show that: 1) decidual macrophages undergo an M1-like polarization during spontaneous term and preterm labor; 2) M2-like macrophages are more abundant than M1-like macrophages in decidual tissue; 3) decidual M2-like macrophages are reduced in preterm pregnancies compared to term pregnancies, regardless of the presence of labor; 4) decidual macrophages express high levels of TNF and IL12, but low levels of PPARγ, during spontaneous preterm labor; 5) decidual macrophages from women who underwent spontaneous preterm labor display plasticity by M1↔M2 polarization in vitro; 6) incubation with rosiglitazone reduces the expression of TNF and IL12 in decidual macrophages from women who underwent spontaneous preterm labor; and 7) treatment with rosiglitazone reduces the rate of LPS-induced preterm birth and improves neonatal outcomes by reducing the systemic pro-inflammatory response in B6 mice and down-regulating mRNA and protein expression of NFκB, TNF, and IL10 in decidual and myometrial macrophages. In summary, we demonstrated that decidual M1-like macrophages are associated with spontaneous preterm labor, and that PPARγ activation via rosiglitazone can attenuate the macrophage-mediated pro-inflammatory response, preventing preterm birth and improving neonatal outcomes. These findings suggest that the PPARγ pathway is a new molecular target for future preventative strategies for spontaneous preterm labor/birth. PMID:26889045

Adaptive Calcified Matrix Response of Dental Pulp to Bacterial Invasion Is Associated with Establishment of a Network of Glial Fibrillary Acidic Protein+/Glutamine Synthetase+ Cells

PubMed Central

Farahani, Ramin M.; Nguyen, Ky-Anh; Simonian, Mary; Hunter, Neil

2010-01-01

We report evidence for anatomical and functional changes of dental pulp in response to bacterial invasion through dentin that parallel responses to noxious stimuli reported in neural crest-derived sensory tissues. Sections of resin-embedded carious adult molar teeth were prepared for immunohistochemistry, in situ hybridization, ultrastructural analysis, and microdissection to extract mRNA for quantitative analyses. In odontoblasts adjacent to the leading edge of bacterial invasion in carious teeth, expression levels of the gene encoding dentin sialo-protein were 16-fold greater than in odontoblasts of healthy teeth, reducing progressively with distance from this site of the carious lesion. In contrast, gene expression for dentin matrix protein-1 by odontoblasts was completely suppressed in carious teeth relative to healthy teeth. These changes in gene expression were related to a gradient of deposited reactionary dentin that displayed a highly modified structure. In carious teeth, interodontoblastic dentin sialo-protein− cells expressing glutamine synthetase (GS) showed up-regulation of glial fibrillary acidic protein (GFAP). These cells extended processes that associated with odontoblasts. Furthermore, connexin 43 established a linkage between adjacent GFAP+/GS+ cells in carious teeth only. These findings indicate an adaptive pulpal response to encroaching caries that includes the deposition of modified, calcified, dentin matrix associated with networks of GFAP+/GS+ interodontoblastic cells. A regulatory role for the networks of GFAP+/GS+ cells is proposed, mediated by the secretion of glutamate to modulate odontoblastic response. PMID:20802180

[Recombinant hFOXA2 and hPDX1 lentivirus induced dental pulp stem cells from deciduous teeth reprogramming for insulin-producing cells].

PubMed

Shi, Jian-feng; Zhu, Chun-hui; Liu, Jin; Sun, Jun-yi; Rao, Guo-zhou; Li, Ang

2013-12-01

The purpose of this study was to culture and identify dental pulp stem cells(DPSCs) from deciduous teeth in vitro and construct the recombinant hFOXA2 and hPDX1 lentivirus vectors and transfect the DPSCs to induce insulin-producing cells (IPCs). DPSCs were separated and cultured by enzyme digest method, and purified by limited dilution method. Flow cytometry was used to determine the surface marker expression of the DPSCs, and the ability of multiple differentiations was determined by specific staining. hFOXA2 and hPDX1 genes were amplified by PCR, and the recombinant hFOXA2 and hPDX1 lentivirus vectors were reconstructed and transfected into 293T cells by lipofectamine2000 for virus packaging. The viral infection efficiency and titer were determined through fluorescence cell count. The recombinant virus was used to infect the DPSCs cells via multiplicity of infection (MOI) and induce the DPSCs reprogramming for IPCs. Immunofluorescence staining was used to measure the expression of proinsulin, FOXA2 and PDX1. ELISA method was used to detect the insulin secretion. The data was analyzed Using SPSS13.0 software package. DPSCs were isolated and cultured successfully. Cell surface highly expressed STRO-1 (98.01%), CDl46 (98.51%), CD34 (99.54%) and CD45 (24.08%). The multi-lineage differentiation capacity into osteoblasts, chondrocytes, and adipose was achieved. The recombinant hFOXA2 and hPDX1 lentivirus vectors were successfully constructed. Double enzyme digestion and sequencing appraisal showed that the sequence was fully consistent with GenBank retrieval. Virus packing efficiency was (96.15±0.17) % and (95.49±0.21) % respectively, and the infection titer was about 1.80±108 GTU/mL. The best MOI of the virus was 20. After inducing the cells to express proinsulin, FOXA2 and PDX1, insulin secretion volume was about 1.92 μmol/L. Compared with the uninduced group and control group, insulin secretion increased significantly (P<0.01). The recombinant transcription factor virus can activate cell reprogramming mechanism, form insulin-producing cells, and can be used for gene therapy of diabetes seed cells. Supported by Science and Technology Research Program of Shaanxi Province (2009K17-06) and Science and Technology Innovation as a Whole Plan Resources Leading Industry Key Technology (Chain) Project of Shaanxi Province (2011KTCL03-24).

Wear resistance of a modified polymethyl methacrylate artificial tooth compared to five commercially available artificial tooth materials.

PubMed

Kamonwanon, Pranithida; Yodmongkol, Sirasa; Chantarachindawong, Rojcharin; Thaweeboon, Sroisiri; Thaweeboon, Boonyanit; Srikhirin, Toemsak

2015-08-01

Wear resistance is a limitation of artificial denture teeth. Improving the wear resistance of conventional artificial denture teeth is of value to prosthodontic patients. The purpose of this in vitro study was to evaluate the wear resistance and hardness of modified polymethyl methacrylate artificial denture teeth compared to 5 commercially available artificial tooth materials. This study evaluated 180 artificial denture teeth (6 groups) that included 3 groups of conventional artificial teeth (MajorDent, Cosmo HXL, and Gnathostar), 2 groups of composite resin artificial teeth (Endura and SR Orthosit PE), and 1 group of modified surface artificial teeth. The flattened buccal surface of each tooth (n=15) was prepared for investigation with the Vickers hardness test and the elucidate wear test (n=15) by using a brushing machine. Each group was loaded for 18,000 cycles, at 2 N, and 150 rpm. The wear value was identified with a profilometer. The data were statistically analyzed by using 1-way ANOVA and post hoc Turkey honestly significant difference tests (α=.001). The tribologies were observed under a scanning electron microscope, and the cytotoxicities were evaluated by MTT assay. The Vickers hardnesses ranged from 28.48 to 39.36. The wear depths and worn surface area values ranged from 1.12 to 10.79 μm and from 6.74 to 161.95 μm(2). The data revealed that the modified artificial denture teeth were significantly harder and exhibited significantly higher wear resistance than did the conventional artificial teeth (P<.001). The scanning electron microscopic images revealed cross sections of the conventional artificial denture teeth with intensively worn surface areas after brushing. The cytotoxicity test revealed 97.85% cell viability, which indicates the nontoxicity of the modified surface of this material. Within the limitations of this study, the polymethyl methacrylate modified surface artificial denture teeth was not significantly different from that of the composite resin artificial denture teeth, with the exceptions that the surface was harder and more wear resistant. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Warburg-like Glycolysis and Lactate Shuttle in Mouse Decidua during Early Pregnancy*

PubMed Central

Zuo, Ru-Juan; Gu, Xiao-Wei; Qi, Qian-Rong; Wang, Tong-Song; Zhao, Xu-Yu; Liu, Ji-Long; Yang, Zeng-Ming

2015-01-01

Decidualization is an essential process of maternal endometrial stromal cells to support pregnancy. Although it is known that enhanced glucose influx is critical for decidualization, the underlying mechanism in regulating glucose metabolism in decidua remains insufficiently understood. Here, we demonstrate that aerobic glycolysis-related genes and factors are all substantially induced during decidualization, indicating the existence of Warburg-like glycolysis in decidua. In vitro, progesterone activates hypoxia-inducible factor 1α (Hif1α) and c-Myc through Pi3k-Akt signaling pathway to maintain aerobic glycolysis in decidualizing cells. Knocking down of pyruvate kinase M2 (Pkm2) attenuates the induction of decidual marker gene. Decidual formation in vivo is also impaired by glycolysis inhibitor 3-bromopyruvate. Besides, lactate exporter monocarboxylate transporter 4 (Mct4) is induced in newly formed decidual cells, whereas lactate importer Mct1 and proliferation marker Ki-67 are complementarily located in the surrounding undifferentiated cells, which are supposed to consume lactate for proliferation. Hif1α activation is required for lactate-dependent proliferation of the undifferentiated cells. Inhibition of lactate flux leads to compromised decidualization and decelerated lactate-dependent proliferation. In summary, we reveal that Warburg-like glycolysis and local lactate shuttle are activated in decidua and play important roles for supporting early pregnancy. PMID:26178372

Implications of resin-based composite (RBC) restoration on cuspal deflection and microleakage score in molar teeth: Placement protocol and restorative material.

PubMed

McHugh, Lauren E J; Politi, Ioanna; Al-Fodeh, Rami S; Fleming, Garry J P

2017-09-01

To assess the cuspal deflection of standardised large mesio-occluso-distal (MOD) cavities in third molar teeth restored using conventional resin-based composite (RBC) or their bulk fill restorative counterparts compared with the unbound condition using a twin channel deflection measuring gauge. Following thermocycling, the cervical microleakage of the restored teeth was assessed to determine marginal integrity. Standardised MOD cavities were prepared in forty-eight sound third molar teeth and randomly allocated to six groups. Restorations were placed in conjunction with (and without) a universal bonding system and resin restorative materials were irradiated with a light-emitting-diode light-curing-unit. The dependent variable was the restoration protocol, eight oblique increments for conventional RBCs or two horizontal increments for the bulk fill resin restoratives. The cumulative buccal and palatal cuspal deflections from a twin channel deflection measuring gauge were summed, the restored teeth thermally fatigued, immersed in 0.2% basic fuchsin dye for 24h, sectioned and examined for cervical microleakage score. The one-way analysis of variance (ANOVA) identified third molar teeth restored using conventional RBC materials had significantly higher mean total cuspal deflection values compared with bulk fill resin restorative restoration (all p<0.0001). For the conventional RBCs, Admira Fusion (bonded) third molar teeth had significantly the lowest microleakage scores (all p<0.001) while the Admira Fusion x-tra (bonded) bulk fill resin restored teeth had significantly the lowest microleakage scores compared with Tetric EvoCeram Bulk Fill (bonded and non-bonded) teeth (all p<0.001). Not all conventional RBCs or bulk fill resin restoratives behave in a similar manner when used to restore standardised MOD cavities in third molar teeth. It would appear that light irradiation of individual conventional RBCs or bulk fill resin restoratives may be problematic such that material selection is vital in the absence of clinical data. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Evaluation of marginal adaptation of root-end filling materials using scanning electron microscopy.

PubMed

Oliveira, Helder Fernandes; Gonçalves Alencar, Ana Helena; Poli Figueiredo, José Antônio; Guedes, Orlando Aguirre; de Almeida Decurcio, Daniel; Estrela, Carlos

2013-01-01

The importance of perfect apical seal in endodontics, more specifically in periradicular surgery, is the motivation/reason for development of root-end filling materials with favorable physical, chemical and biological characteristics. The aim of this in vitro study was to evaluate the marginal adaptation of root-end filling materials using scanning electron microscopy. Twenty five human maxillary anterior teeth were prepared using a K-File #50 to 1 mm short of the apical foramen and filled with gutta-percha and Sealapex using the lateral compaction technique. The apical 3 mm of the roots were sectioned perpendicularly to the long axis of the teeth. A 3-mm-deep root-end cavity was prepared using ultrasonic tips powered by an Enac ultrasonic unit. The teeth were randomly assigned to five groups according to the materials tested including IRM, amalgam, ProRoot MTA, Super-EBA and Epiphany/Resilon. Root-end cavities were filled with the materials prepared according to the manufacturers' instructions. The root apices were carefully prepared for sputter coating and later evaluation using Scanning Electron Microscope (SEM). The images of root-end fillings were divided into four quadrants and distributed into five categories according to the level of marginal adaptation between the root-end material and the root canal walls. The Fisher exact test with Bonferroni correction was used for statistical analysis. The level of significance was set at P = 0.005. SEM images showed the presence of gaps in the root-end filling materials. No significant difference was observed between the tested materials (P > 0.005). ProRoot MTA, IRM, amalgam, Super-EBA and Epiphany/Resilon showed similar marginal adaptation as root-end filling materials.

Computer-aided analysis of digital dental impressions obtained from intraoral and extraoral scanners.

PubMed

Bohner, Lauren Oliveira Lima; De Luca Canto, Graziela; Marció, Bruno Silva; Laganá, Dalva Cruz; Sesma, Newton; Tortamano Neto, Pedro

2017-11-01

The internal and marginal adaptation of a computer-aided design and computer-aided manufacturing (CAD-CAM) prosthesis relies on the quality of the 3-dimensional image. The quality of imaging systems requires evaluation. The purpose of this in vitro study was to evaluate and compare the trueness of intraoral and extraoral scanners in scanning prepared teeth. Ten acrylic resin teeth to be used as a reference dataset were prepared according to standard guidelines and scanned with an industrial computed tomography system. Data were acquired with 4 scanner devices (n=10): the Trios intraoral scanner (TIS), the D250 extraoral scanner (DES), the Cerec Bluecam intraoral scanner (CBIS), and the Cerec InEosX5 extraoral scanner (CIES). For intraoral scanners, each tooth was digitized individually. Extraoral scanning was obtained from dental casts of each prepared tooth. The discrepancy between each scan and its respective reference model was obtained by deviation analysis (μm) and volume/area difference (μm). Statistical analysis was performed using linear models for repeated measurement factors test and 1-way ANOVA (α=.05). No significant differences in deviation values were found among scanners. For CBIS and CIES, the deviation was significantly higher (P<.05) for occlusal and cervical surfaces. With regard to volume differences, no statistically significant differences were found (TIS=340 ±230 μm; DES=380 ±360 μm; CBIS=780 ±770 μm; CIES=340 ±300 μm). Intraoral and extraoral scanners showed similar trueness in scanning prepared teeth. Higher discrepancies are expected to occur in the cervical region and on the occlusal surface. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Microleakage of different temporary filling materials in primary teeth.

PubMed

Odabas, Mesut Enes; Tulunoglu, Ozlem; Ozalp, Serife Ozdemir; Bodur, Haluk

2009-01-01

The aim of this study was to compare the sealing properties of IRM, Coltosol, Cavit G, Adhesor and Clip, which used as temporary filling material in coronal access openings in extracted human primary teeth. Standardized access cavities of 2 x 2 mm were prepared in the eighty-four, caries-free human primary anterior teeth. The teeth were divided randomly into five groups of 16 teeth each. Temporary restorative materials Group A: IRM (Dentsply), Group B: Coltosol (Coltone), Group C: Cavit G (3M), Group D: Adhesor (Spofa Dental) and Group E: Clip (Voco) were applied according to the manufacturer's directions. The specimens were immersed silver nitrate and placed in film developer under fluorescent for 24 hours. The sectioned specimens were evaluated under a digital microscope at x 20 magnifications and blindly scored for microleakage. Clip presented the least microleakage value whereas; Adhesor and IRM presented the higher microleakage values. There were statistically significant differences between Clip and the others groups, while there were no statistically significant differences in microleakage between IRM, Adhesor, Coltosol and Cavit G. However the leakage scores of Clip and Cavit G were congruent (p = 0.454). Amongst the five materials, Clip exhibited a better sealing ability.

Effect of the CO2 laser (9.6μm) on the dental pulp in humans

NASA Astrophysics Data System (ADS)

Wigdor, Harvey A.; Walsh, Joseph T., Jr.; Mostafi, Reza

2000-03-01

There has been great interest in the potential use of a laser to replace the dental handpiece (drill). Ideally a laser emitting radiation that is absorbed strongly by both the water and hydroxyapatite in teeth, would be a more efficient laser. Previous investigators showed that the 9.3 and 9.6 micron wavelength bands of the CO2 laser contain hydroxyapatite absorption peaks. For this study, human patients who were to have teeth removed for either orthodontic or periodontal reasons were used. A total of 16 teeth were irradiated. The number of teeth treated per patient varied from 1 - 4. The laser used was a prototype CO2 laser (ESC Medical Systems, Yokneam, Israel). The CO2 laser emits 50 mJ 60 microsecond-long pulses of 9.6 micrometer radiation in a beam focused to a 300 micrometer diameter (i/e2) spot. The pulps in both the laser and handpiece prepared holes appeared similar and had no apparent inflammation or vascular changes. It appears from this small sample of laser treated human teeth that this laser has an equal effect to the dental pulpal tissue when compared to the dental handpiece.

Assisted eruption of impacted teeth into an alveolar bone graft in a patient with cleft lip and palate.

PubMed

Peamkaroonrath, Chonthicha; Manosudprasit, Montien; Godfrey, Keith

2008-11-01

To assist the eruption of impacted upper teeth into an alveolar bone graft in a patient with a unilateral cleft lip and palate. An 8-year-old Thai boy with left unilateral complete cleft lip and palate had the chief complaint of anterior crossbite. He presented with a mild skeletal 3, dental Class III subdivision malocclusion, anterior crossbite, left unilateral posterior crossbite, moderate crowding in the upper arch with impaction of upper the left lateral incisor (tooth 22) and canine (tooth 23). In the first phase of treatment the posterior crossbite was corrected with a removable appliance with a 3-way screw. In the second phase the impacted teeth were surgically exposed, moved into the alveolar bone graft and the teeth aligned with fixed appliances. The upper left lateral incisor was extracted because of its questionable longevity. The orthodontic treatment resulted in normal overjet, overbite and an acceptable facial profile. A prosthesis replaced tooth 22. Forced eruption of impacted teeth can be carried out successfully in the cleft patients after an appropriate treatment plan has been formulated and following preparation of alveolar bone graft in the cleft site.

Decidualized endometrioma during pregnancy: recognizing an imaging mimic of ovarian malignancy.

PubMed

Poder, Liina; Coakley, Fergus V; Rabban, Joseph T; Goldstein, Ruth B; Aziz, Seerat; Chen, Lee-may

2008-01-01

To present the ultrasound and magnetic resonance imaging findings that may allow for a prospective diagnosis and expectant management of decidualized endometriomas because the rare occurrence of decidualization in the ectopic endometrial stroma of an endometrioma during pregnancy can mimic ovarian cancer at imaging. Smooth lobulated mural nodules with prominent internal vascularity were noted in an apparent right ovarian endometrioma on serial ultrasound studies in a 34-year-old woman at 12, 21, 27, and 30 weeks of gestation. Magnetic resonance imaging demonstrated the nodules to be strikingly similar in intensity and texture to the decidualized endometrium in the uterus on T2-weighted sequences. A provisional diagnosis of decidualized endometrioma allowed for expectant management with immediate postpartum resection and confirmation of the diagnosis. Decidualized endometrioma can mimic ovarian malignancy during pregnancy, but a prospective diagnosis may be possible when solid smoothly lobulated nodules with prominent internal vascularity within an endometrioma are seen from early in pregnancy, and the nodules demonstrate marked similarity in signal intensity and texture with the decidualized endometrium in the uterus at magnetic resonance imaging.

VIP induces the decidualization program and conditions the immunoregulation of the implantation process.

PubMed

Grasso, Esteban; Gori, Soledad; Paparini, Daniel; Soczewski, Elizabeth; Fernández, Laura; Gallino, Lucila; Salamone, Gabriela; Martinez, Gustavo; Irigoyen, Marcela; Ruhlmann, Claudio; Pérez Leirós, Claudia; Ramhorst, Rosanna

2018-01-15

The decidualization process involves phenotype and functional changes on endometrial cells and the modulation of mediators with immunoregulatory properties as the vasoactive intestinal peptide (VIP). We investigate VIP contribution to the decidualization program and to immunoregulation throughout the human embryo implantation process. The decidualization of Human endometrial stromal cell line (HESC) with Medroxyprogesterone-dibutyryl-cAMP increased VIP/VPAC-receptors system. In fact, VIP could induce decidualization increasing differentiation markers (IGFBP1, PRL, KLF13/KLF9 ratio, CXCL12, CXCL8 and CCL2) and allowing Blastocyst-like spheroids (BLS) invasion in an in vitro model of embryo implantation. Focus on the tolerogenic effects, decidualized cells induced a semi-mature profile on maternal dendritic cells; restrained CD4 + cells recruitment while increased regulatory T-cells recruitment. Interestingly, the human blastocyst conditioned media from developmentally impaired embryos diminished the invasion and T-regulatory cells recruitment in these settings. These evidences suggest that VIP contributes to the implantation process inducing decidualization, allowing BLS invasion and favoring a tolerogenic micro-environment. Copyright © 2017 Elsevier B.V. All rights reserved.

Molecular identification and quantification of bacteria from endodontic infections using real-time polymerase chain reaction.

PubMed

Blome, B; Braun, A; Sobarzo, V; Jepsen, S

2008-10-01

It was the aim of the present study to evaluate root canal samples for the presence and numbers of specific species as well as for total bacterial load in teeth with chronic apical periodontitis using quantitative real-time polymerase chain reaction (PCR). Forty adult patients with one radiographically documented periapical lesion were included. Twenty teeth presented with primary infections and 20 with secondary infections, requiring retreatment. After removal of necrotic pulp tissue or root canal filling, a first bacterial sample was obtained. Following chemo-mechanical root canal preparation a second sample was taken and a third sample was obtained after 14 days of intracanal dressing with calcium hydroxide. Analysis by real-time PCR enabled the quantification of total bacterial counts and of nine selected species. Root canals with primary infections harbored significantly more bacteria (by total bacterial count) than teeth with secondary infections (P < 0.05). Mean total bacterial count in the retreatment group was 2.1 x 10(6) and was significantly reduced following root canal preparation (3.6 x 10(4)) and intracanal dressing (1.4 x 10(5)). Corresponding values for primary infections were: 4.6 x 10(7), 3.6 x 10(4), and 6.9 x 10(4). The numbers of the selected bacteria and their detection frequency were also significantly reduced. Root canals with primary infections contained a higher bacterial load. Chemo-mechanical root canal preparation reduced bacterial counts by at least 95%.

Pathological study of pulp treated with chemicals after Er:YAG laser preparation.

PubMed

Akashi, Go; Kato, Junji; Hirai, Yoshito

2006-12-01

The aim of this study was to clarify pulp reaction following cavity preparation with an Er:YAG laser and subsequent treatment with topically applied chemicals to achieve a high resin bond strength. The application of chemicals has been found to effectively remove or reform the denatured layer produced by Er:YAG laser irradiation and has been proposed as a new strategy for improving resin bond strength. However, very little is known about pulp reaction to chemical procedures. Class 5 dentin cavities were prepared with an Er:YAG laser in 128 teeth in nine adult dogs. The teeth were then coated with glutaraldehyde (GA group), or phosphoric acid and sodium hypochlorite (PA group) to reform or remove the denatured layer. All the cavities were then restored with composite resin. In the control group, no chemical application was carried out prior to restoration. The animals were sacrificed immediately after, and at 7 and 90 days following treatment. The treated teeth were then extracted for histopathological examination of the pulp. Pathological evaluation of the pulp indicated a good condition in each group at each of the three observation time points. No bacterial growth was observed on the cavity walls or bacterial invasion into the dentinal tubules or pulp chambers in any of the groups at any of the observation periods. Our findings suggest that the application of chemicals to remove or reform denatured layers is effective in obtaining better composite resin restoration with no pulp damage.

In-vitro evaluation of Er:YAG laser irradiation in apicoectomy and retrofilling cavity preparation compared to two other techniques

NASA Astrophysics Data System (ADS)

Camargo, Selma C. C.; Gavini, Giulio; Eduardo, Carlos d. P.; Aun, Carlos E.; Coil, Jeffrey M.

1998-04-01

The aim of this research was to evaluate under SEM observation, the apical cut surface and retrofilling cavity prepared with Er:YAG laser and two other conventional techniques. Thirty extracted human teeth were divided into two groups of 15 teeth each. For Group 1 apicoectomy was performed using high speed handpiece and diamond burs. For Group 2 Er:YAG* laser irradiation (wavelength of 2.94 micrometer, pulse width of 250 - 500 microseconds) was used in 400 mJ of energy, frequency of 6 Hz, on focus mode under destiled water refrigeration. Each group was divided into 3 subgroups. For groups G1A and G2A, retrofilling cavity preparations were performed using low speed handpiece and burs, for groups G1B and G2B Enac technique was indicated. Groups G1C and G2C Er:YAG laser irradiation was used under same energy level previously described. All specimens were prepared for SEM observations. Pictures were taken under 30x and 600x magnification. Two different observers analyzed the smoothness and morphological appearance of those preparations. Data's were collected showing a smoothness surface, no debries or smear layer on group 2 (Laser irradiation) compared to group 1. Differences were also noted when retrofiling cavities were analyzed.

miR-200 Regulates Endometrial Development During Early Pregnancy

PubMed Central

Mainigi, Monica A.; Word, R. Ann; Kraus, W. Lee; Mendelson, Carole R.

2016-01-01

For successful embryo implantation, endometrial stromal cells must undergo functional and morphological changes, referred to as decidualization. However, the molecular mechanisms that regulate implantation and decidualization are not well defined. Here we demonstrate that the estradiol- and progesterone-regulated microRNA (miR)-200 family was markedly down-regulated in mouse endometrial stromal cells prior to implantation, whereas zinc finger E-box binding homeobox-1 and -2 and other known and predicted targets were up-regulated. Conversely, miR-200 was up-regulated during in vitro decidualization of human endometrial stromal cells. Knockdown of miR-200 negatively affected decidualization and prevented the mesenchymal-epithelial transition-like changes that accompanied decidual differentiation. Notably, superovulation of mice and humans altered miR-200 expression. Our findings suggest that hormonal alterations that accompany superovulation may negatively impact endometrial development and decidualization by causing aberrant miR-200 expression. PMID:27533790

Restoration of Endodontically Treated Molars Using All Ceramic Endocrowns

PubMed Central

Carlos, Roopak Bose; Thomas Nainan, Mohan; Pradhan, Shamina; Roshni Sharma; Benjamin, Shiny; Rose, Rajani

2013-01-01

Clinical success of endodontically treated posterior teeth is determined by the postendodontic restoration. Several options have been proposed to restore endodontically treated teeth. Endocrowns represent a conservative and esthetic restorative alternative to full coverage crowns. The preparation consists of a circular equigingival butt-joint margin and central retention cavity into the entire pulp chamber constructing both the crown and the core as a single unit. The case reports discussed here are moderately damaged endodontically treated molars restored using all ceramic endocrowns fabricated using two different systems, namely, CAD/CAM and pressed ceramic. PMID:24455318

[Advantages and disadvantages of endocrown restorations of endodontically treated teeth with large coronal destruction].

PubMed

Bao, X D

2018-04-09

The strength of endodontically treated teeth were reduced apparently because of structural damage, therefore further reduction of healthy tissue should be avoided as much as possible in restoration. Endocrown made by chair-side CAD/CAM is some kind of minimal invasive restoration, and the retention of restoration is achieved by reliable bonding and macromechanial retention forces. Without post preparation, the root structure could be resevered. Following the indications and use of biomechanical dentin-like CAD/CAM materials could reduce the adverse effect of tensile stress on cervical part.

[A ten-year clinical study of cracked teeth restored with glass ceramic crowns].

PubMed

Luo, X P; Yuan, Y; Shi, Y J; Qian, D D

2016-10-09

Objective: To evaluate the clinic performance of high strength glass ceramic crowns for the painful cracked teeth during a 10-year observation period. Methods: Forty-two posterior teeth from 36 patients were diagnosed as having a crack, biting painful and sensitivity to cold were selected in the Department of Prosthodontic, Institute and Hospital of Stomatology, Nanjing University Medical School. The lost-wax hot pressed glass ceramic crowns were bonded on the minimally invasive prepared teeth by modern adhesive technology. Patients were interviewed and went through clinic examination after one week, one month, and every six months. Results: The effectiveness of 42 glass ceramic crowns for cracked teeth was evaluated for a mean observation time over 10-year. At the first week, 29(81%) patients were free of pain, three still had sensitivity to cold and chewing pain, three still had sensitivity to cold, one had painful to cold and hot. After one month, two patients still had chewing pain, and one tooth needed endodontic treatment after six months. In 10 years, 2(5%) all ceramic crowns were broken, the other 40 restorations kept good clinical performances with a 10-year survival rate of 95%. Conclusions: The high strength glass ceramic crowns are very effective and successful in treating the cracked teeth and then keep the good mastication function and appearance.

An in vivo comparison of antimicrobial efficacy of sodium hypochlorite and Biopure MTAD™ against enterococcus faecalis in primary teeth: A qPCR study.

PubMed

Tulsani, S G; Chikkanarasaiah, N; Bethur, S

2014-01-01

Biopure MTAD™, a new root canal irrigant has shown promising results against the most common resistant microorganism, E. faecalis, in permanent teeth. However, there is lack of studies comparing its antimicrobial effectiveness with NaOCl in primary teeth. The purpose of this study was to compare the in vivo antimicrobial efficacy of NaOCl 2.5% and Biopure MTAD™ against E. faecalis in primary teeth. Forty non vital single rooted primary maxillary anterior teeth of children aged 4-8 years, were irrigated either with NaOCl 2.5% (n=15), Biopure MTAD™ (n=15) and 0.9% Saline (n=10, control group). Paper point samples were collected at baseline (S1) and after chemomechanical preparation (S2) during the pulpectomy procedure. The presence of E. faecalis in S1 & S2 was evaluated using Real time Polymerase Chain Reaction. Statistical significant difference was found in the antimicrobial efficacy of NaOCl 2.5 % and BioPure MTAD™ when compared to saline (p>0.05). However, no statistical significant difference was found between the efficacies of both the irrigants. NaOCl 2.5% and BioPure MTAD™, both irrigants are equally efficient against E. faecalis in necrotic primary anterior teeth. MTAD is a promising irrigant, however clinical studies are required to establish it as ideal root canal irrigant in clinical practice.

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

PubMed Central

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

2017-01-01

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

Three-year clinical follow-up of posterior teeth restored with leucite-reinforced ips empress onlays and partial veneer crowns.

PubMed

Murgueitio, Rafael; Bernal, Guillermo

2012-07-01

The aim of this study was to analyze the survival rate and failure mode of IPS leucite-reinforced ceramic onlays and partial veneer crowns regarding thickness under the following clinical conditions: vital versus nonvital teeth, tooth location, and type of opposing dentition. Teeth were prepared according to established guidelines for ceramic onlays and partial veneer crowns. Before cementation, the restorations were measured for occlusal thickness at the central fossa, mesial, and distal marginal ridges, and functional and nonfunctional cusps. A total of 210 ceramic restorations were cemented in 99 patients within a mean observation period of 2.9 ± 1.89 years. The mode of failure was classified and evaluated as (1) adhesive, (2) cohesive, (3) combined failure, (4) decementation, (5) tooth sensitivity, and (6) pulpal necrosis. Kaplan, log-rank, and Cox regression tests were used for statistical analysis. The failure rate was 3.33% (7/210). Increased material thickness produced less probability of failures. Vital teeth were less likely to fail than nonvital teeth. Second molars were five times more susceptible to failure than first molars. Tooth sensitivity postcementation and the type of opposing dentition were not statistically significant in this study. In this study, thickness of the restorations, tooth vitality, and location of teeth in the dental arch influenced restoration failures. © 2012 by the American College of Prosthodontists.

Evaluation of bond strength of self-etching adhesives having different pH on primary and permanent teeth dentin.

PubMed

Ozmen, Bilal; Koyuturk, Alp Erdin; Tokay, Ugur; Cortcu, Murat; Sari, Mustafa Erhan

2015-10-16

The purpose of this in vitro study was to evaluate the dentin shear bond strength of 4 self-etching adhesives having a different pH on primary and permanent teeth dentin. The occlusal enamel was removed from 60 freshly extracted third molar and 60 primary second molar human teeth, which were randomly separated into 4 groups (n = 15). Four adhesive systems were applied: G-Bond (GC Corporation, Tokyo, Japan, pH: 1.5), Futura Bond M (Voco, Cuxhaver, Germany, pH: 1.4), Adper Prompt L-Pop (3M/ESPE, St Paul, MN, USA, pH: 0.8), and Clearfil S(3) Bond (Kuraray Medical, Tokyo, Japan, pH: 2.7) according to the manufacturer's instructions. After the application of dentin bonding agents, a composite resin material (Z250 Restorative A2, 3M ESPE, St. Paul, MN, USA) for permanent teeth and a compomer resin material (Dyract Extra A2, Dentsply, Konstanz, Germany) for primary teeth was applied onto the prepared dentin surfaces. The data were obtained by using a universal test machine at a crosshead speed of 1 mm/min. The mean values were compared using Tukey's multiple comparison test. Although there was no difference between adhesives on the permanent teeth, Clearfil S3 adhesive showed higher bond (18.07 ± 0.58 MPa) (P>0.05). Lower bond strength values were obtained from primary teeth and especially G-Bond adhesive (9.36 ± 0.48 MPa) (P<0.05). Self-etching adhesives with different pH and solvent types can be used successfully for permanent teeth dentin but adhesives with low pH did not provide greater shear bond strength values.

Divergent Hydraulic Safety Strategies in Three Co-occurring Anacardiaceae Tree Species in a Chinese Savanna

PubMed Central

Zhang, Shu-Bin; Zhang, Jiao-Lin; Cao, Kun-Fang

2017-01-01

Vulnerability segmentation, the condition under which plant leaves are more vulnerable to drought-induced cavitation than stems, may act as a “safety valve” to protect stems from hydraulic failure. Evergreen, winter-deciduous, and drought-deciduous tree species co-occur in tropical savannas, but there have been no direct studies on the role of vulnerability segmentation and stomatal regulation in maintaining hydraulic safety in trees with these three leaf phenologies. To this end, we selected three Anacardiaceae tree species co-occurring in a Chinese savanna, evergreen Pistacia weinmanniifolia, drought-deciduous Terminthia paniculata, and winter-deciduous Lannea coromandelica, to study inter-species differentiation in leaf and stem hydraulic safety. We found that the two deciduous species had significantly higher sapwood-specific hydraulic conductivity and leaf-specific hydraulic conductance than the evergreen species. Moreover, two deciduous species were more vulnerable to stem cavitation than the evergreen species, although both drought-deciduous species and evergreen species had drought-resistance leaves. The evergreen species maintained a wide hydraulic safety margin (HSM) in stems and leaves; which was achieved by embolism resistance of both stems and leaves and isohydric stomatal control. Both deciduous species had limited HSMs in stems and leaves, being isohydric in the winter-deciduous species and anisohydric in drought-deciduous species. The difference in water potential at 50% loss of hydraulic conductivity between the leaves and the terminal stems (P50leaf−stem) was positive in P. weinmanniifolia and L. coromandelica, whereas, T. paniculata exhibited a lack of vulnerability segmentation. In addition, differences in hydraulic architecture were found to be closely related to other structural traits, i.e., leaf mass per area, wood density, and sapwood anatomy. Overall, the winter-deciduous species exhibits a drought-avoidance strategy that maintains the hydraulic safety of the more carbon-costly stems by sacrificing cheaper and more vulnerable leaves, while the evergreen species exhibits a hydraulic strategy of drought tolerance with strong stomatal regulation. In contrast, the drought-deciduous species lacks vulnerability segmentation and sheds leaves at the expense of top shoots during peak drought. This study demonstrates that even sympatric tree species that differ in leaf phenology can exhibit divergent adaptive hydraulic safety strategies. PMID:28149302

Gross Anatomy of Pampas Deer (Ozotoceros bezoarticus, Linnaeus 1758) Mouth and Pharynx.

PubMed

Pérez, W; Vazquez, N; Ungerfeld, R

2017-04-01

The aims of this study were to describe the anatomy of the mouth and pharynx of the pampas deer, and to consider its evolutionary feeding niche according to those characteristics. Gross dissections of the mouth and pharynx were performed in 15 animals, 10 adult females and five young animals under 1 year (three males and two females), all dead by causes unrelated to this anatomical region. The upper lip entered in the constitution of a pigmented nasolabial plane. The masseter muscles weighed 43.8 ± 3.5 g and represented 0.23% of body weight, which corresponds to ruminants of feeders intermediate to grazers and browsers. Parotid glands represented 0.08% of the body weight, characteristic that also categorize the pampas deer as belonging to the intermediate feeding group. The dental formula was the same of the domestic ruminants. The upper incisors and canines were absent, and instead of them, there was a dental pad (Pulvinus dentalis). The upper canine teeth were present only in the deciduous dentition. The existence of a brachydont dentition turns Ozotoceros very vulnerable to continuous use as there is no compensatory teeth growth. The particular anatomy of the mouth and lips of this animal was adapted to a very selective feeding, taking highly nutritious sprouts beyond plant category. In conclusion and in addition to previous studies of anatomy of the digestive organs in this species, pampas deer may be categorized as belonging to the intermediate type of feeding. © 2016 Blackwell Verlag GmbH.

Parental views on delivering preventive advice to children referred for treatment of dental caries under general anaesthesia: a qualitative investigation.

PubMed

Aljafari, A K; Scambler, S; Gallagher, J E; Hosey, M T

2014-06-01

To: 1, Explore opinions of parents of children undergoing caries treatment under general anaesthesia (GA) regarding delivery of oral health advice; 2, Discover current oral health practices and beliefs; 3, Inform further research and action. Qualitative study using semi-structured interviews and thematic data analysis, sampling parents of children aged 3-10 years undergoing GA tooth extraction due to dental caries. Twenty nine parents were interviewed (mean age 38.9 years, range 28-50, sd 6.4). The mean age of their children was seven years (range 3-10, sd 2.1). All children required deciduous tooth extractions (5.1 teeth on average). Those that also required permanent tooth extractions had on average 2.1 permanent teeth extracted. Many parents knew the importance of oral hygiene and sugar limitation, describing it as 'general knowledge' and 'common sense'. However, few understood that fruit juice is potentially cariogenic. Parenting challenges seemed to restrict their ability to control the child's diet and establish oral hygiene. Many reported not previously receiving oral health advice and reported never having fluoride varnish applied. There were requests for more caries prevention information and advice via the internet, schools or video games. Parental oral health knowledge, parenting skills, and previous advice received seem to all be issues related to the oral health of those children. Providing advice, especially in respect to fruit juice cariogenicity and the benefits of fluoride application through a child-friendly website, including a video game, as well as the use of school programmes might be an acceptable approach.

Impact of oral hygiene on oral health-related quality of life of preschool children.

PubMed

Shaghaghian, S; Bahmani, M; Amin, M

2015-08-01

To assess the impact of oral hygiene of preschool children and parental attitude on children's oral health-related quality of life (OHRQoL). In this cross-sectional study, 396 children of Shiraz kindergartens were selected by a randomized cluster sampling. Children's oral hygiene was assessed using the Simplified Debris Index (DI-S) and a self-made questionnaire about oral hygiene habits. Children's OHRQoL was evaluated by the Farsi version of Early Childhood Oral Health Impact Scale (F-ECOHIS). The effect of oral hygiene determinants on OHRQoL was measured using Pearson and Spearman correlation, independent-sample t-test and anova. Children's mean DI-S and F-ECOHIS scores were 1.19 (± 0.77) and 19.36 (±8.42), respectively. Only 75% of the children had their teeth brushed once a day or more, and in 28%, toothbrushing had started before 2 years of age. DI-S values (P < 0.001) and frequency of toothbrushing (P < 0.001) had a statistically significant impact on OHRQoL of the children. Children's OHRQoL was also significantly associated with parents' attitude towards the importance of brushing deciduous teeth (P = 0.002). Oral health status of preschool children in Shiraz was less than optimal and had a significant impact on their OHRQoL. Therefore, improvement of children's OHRQoL could be achieved by improving their home dental care. Strategies promoting parental attitude about the importance of children's toothbrushing may significantly influence children's oral hygiene and are highly recommended. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Brief communication: dental development timing in captive Pan paniscus with comparisons to Pan troglodytes.

PubMed

Bolter, Debra R; Zihlman, Adrienne L

2011-08-01

Dental eruption provides markers of growth and is one component of a chimpanzee's physical development. Dental markers help characterize transitions between life stages, e.g., infant to juvenile. Most of what we know about the timing of development in chimpanzees derives from Pan troglodytes. Much less is known about the sister species, Pan paniscus, with few in captivity and a restricted wild range in central Africa. Here we report on the dental eruption timing for female captive P. paniscus (n = 5) from the Milwaukee and San Diego Zoos whose ages are known and range from birth to age 8.54 years. Some observations were recorded in zoo records on the gingiva during life; others were made at death on the gingiva and on the skeleton. At birth, P. paniscus infants have no teeth emerged. By 0.83 years, all but the deciduous second molars (dm(2) ) (when both upper and lower dentitions are referenced collectively, no super or subscript notation is used) and canines (dc) are emerged. For permanent teeth, results show a sequence polymorphism for an early P4 eruption, not previously described for P. paniscus. Comparisons between P. paniscus and P. troglodytes document absolute timing differences of emergence in upper second incisors (I(2) ), and upper and lower canines (C) and third molars (M3). The genus Pan encompasses variability in growth not previously recognized. These preliminary data suggest that physical growth in captive P. paniscus may be accelerated, a general pattern found in captive P. troglodytes. Copyright © 2011 Wiley-Liss, Inc.

Markers of physiological stress in juvenile bonobos (Pan paniscus): are enamel hypoplasia, skeletal development and tooth size interrelated?

PubMed

Lukacs, John R

2009-07-01

A reduction in enamel thickness due to disrupted amelogenesis is referred to as enamel hypoplasia (EH). Linear EH in permanent teeth is a widely accepted marker of systemic physiological stress. An enigmatic, nonlinear form of EH commonly manifest in great ape and human deciduous canines (dc) is known as localized hypoplasia of primary canines (LHPC). The etiology of LHPC and what it signifies-localized traumatic or systemic physiological stress-remains unclear. This report presents frequency data on LHPC, hypostotic cranial traits, and tooth size in a sample of juvenile bonobos, then tests hypotheses of intertrait association that improve knowledge of the etiology and meaning of LHPC. The fenestration hypothesis is tested using hypostotic cranial traits as a proxy for membrane bone ossification, and the relationship between tooth size, LHPC, and hypostosis is investigated. Macroscopic observations of EH, hypostotic traits, and measurements of buccolingual tooth size were conducted according to established standards. LHPC was found in 51.2% of bonobos (n = 86) and in 26% of dc teeth (n = 269). Hypostotic traits were observed in 55.2% of bonobos (n = 96). A test of the association between LHPC and hypostosis yielded nonsignificant results (chi(2) = 2.935; P = 0.0867). Primary canines were larger in specimens with LHPC than in unaffected specimens (paired samples t test; udc, P = 0.011; ldc, P = 0.018), a result consistent with the fenestration hypothesis of LHPC pathogenesis. Hypostosis was not associated with differences in tooth size (P > 0.05). LHPC may be an indirect indicator of physiological stress, resulting from large, buccally displaced primary canines.

Dental Caries and Their Treatment Needs in 3-5 Year Old Preschool Children in a Rural District of India

PubMed Central

Gupta, Devanand; Momin, Rizwan K; Mathur, Ayush; Srinivas, Kavuri Teja; Jain, Ankita; Dommaraju, Neelima; Dalai, Deepak Ranjan; Gupta, Rajendra Kumar

2015-01-01

Background: Dental problems in the preschool children are neglected by their parents as the deciduous teeth are going to shed off, and hence considered to be of no importance and more of economic burden if attended to them. Aims: This study was to determine the caries prevalence in preschool children (3-5-year-old) of rural Moradabad district, to analyze the specific pattern of dental caries experience in this population and to assess the treatment needs among them. Material and Methods: Children within the age group of 3-5 years attending Anganwadi centers of rural Moradabad district were included in the study. Caries diagnosis was based on decayed, extracted, filled surface (defs) and the treatment needs were recorded using World Health Organization (WHO) oral health assessment form 1997. Results: Out of 1,500 children examined, 48.7% males and 52.6% females did not require any treatment. The mean decayed, extracted, filled teeth (deft) value was found to be significantly high in 5-year-old participants when compared to 3-year-old participants (P < 0.01). Majority of the children required one surface filling followed by two surface fillings, caries arresting sealant care, extraction, crown bridge element, pulp care, and space maintainer. Conclusion: The most common pattern was pit and fissure, then maxillary anterior pattern, posterior proximal pattern, and posterior buccal lingual smooth surface pattern. The mean deft value was higher in males as compared to females. There is a greater need for oral health education among parents and teachers. PMID:25973401

Metallic Burden of Deciduous Teeth and Childhood Behavioral Deficits

PubMed Central

Chan, Tony J.H.; Gutierrez, Carolina; Ogunseitan, Oladele A.

2015-01-01

Attention Deficit/Hyperactivity Disorder (ADHD) affects 5%–8% of children in the U.S. (10% of males and 4% of females). The contributions of multiple metal exposures to the childhood behavioral deficits are unclear, although particular metals have been implicated through their neurotoxicity. The objective of this study was to test the hypothesis that the body burden of Mn is positively correlated with ADHD symptoms. We also investigated the putative roles of Ca, Fe, Pb, and Hg. We collected shed molars from 266 children (138 boys and 128 girls) who lost a tooth between 11 and 13 years of age. The molars were analyzed for metals using ICP-OES. The third grade teacher of each child completed the Teacher’s Disruptive Behavior Disorders Rating Scale (DBD) to produce a score for “Total Disruptive Behavior” and subscale scores for “Attention Deficit Hyperactivity Disorder”, Hyperactivity/Impulsivity, Inattention, and Oppositional/Defiant. The mean Mn, Fe, Pb and Ca concentrations found in teeth was 3.1 ± 2.9 µg/g, 11.4 ± 12.1 µg/g, 0.5 ± 0.7 µg/g, and 3.0 × 105 ± 0.8 × 105 µg/g, respectively. Hg was not detected. No significant association was found between Mn and behavioral deficits. Ca was significantly negatively associated, and Pb showed a significant positive association with Hyperactivity/Impulsivity, Inattention, and Oppositional/Defiant Disorders. These findings call into question the putative independent association of manganese exposure and behavioral deficits in children, when the balance of other metallic burden, particularly Ca and Pb burdens play significant roles. PMID:26084001

The effect of erbium family laser on tensile bond strength of composite to dentin in comparison with conventional method.

PubMed

Shahabi, Sima; Chiniforush, Nasim; Bahramian, Hoda; Monzavi, Abbas; Baghalian, Ali; Kharazifard, Mohammad Javad

2013-01-01

The purpose of this study was to evaluate the effect of Er:YAG and Er,Cr:YSGG laser on tensile bond strength of composite resin to dentine in comparison with bur-prepared cavities. Fifteen extracted caries-free human third molars were selected. The teeth were cut at a level below the occlusal pit and fissure plan and randomly divided into three groups. Five cavities were prepared by diamond bur, five cavities prepared by Er:YAG laser, and the other group prepared by Er,Cr:YSGG laser. Then, all the cavities were restored by composite resin. The teeth were sectioned longitudinally with Isomet and the specimens prepared in dumbbelled shape (n = 36). The samples were attached to special jigs, and the tensile bond strength of the three groups was measured by universal testing machine at a speed of 0.5 mm/min. The results of the three groups were analyzed with one-way ANOVA and Tamhane test. The means and standard deviations of tensile bond strength of bur-cut, Er:YAG laser-ablated, and Er,Cr:YSGG laser-ablated dentine were 5.04 ± 0.93, 13.37 ± 3.87, and 4.85 ± 0.93 MPa, respectively. There is little difference in tensile bond strength of composite resin in Er,Cr:YSGG lased-prepared cavities in comparison with bur-prepared cavities, but the Er:YAG laser group showed higher bond strength than the other groups.

Sustained Endocannabinoid Signaling Compromises Decidual Function and Promotes Inflammation-induced Preterm Birth.

PubMed

Sun, Xiaofei; Deng, Wenbo; Li, Yingju; Tang, Shuang; Leishman, Emma; Bradshaw, Heather B; Dey, Sudhansu K

2016-04-08

Recent studies provide evidence that premature maternal decidual senescence resulting from heightened mTORC1 signaling is a cause of preterm birth (PTB). We show here that mice devoid of fatty acid amide hydrolase (FAAH) with elevated levels ofN-arachidonyl ethanolamide (anandamide), a major endocannabinoid lipid mediator, were more susceptible to PTB upon lipopolysaccharide (LPS) challenge. Anandamide is degraded by FAAH and primarily works by activating two G-protein-coupled receptors CB1 and CB2, encoded by Cnr1 and Cnr2, respectively. We found thatFaah(-/-)decidual cells progressively underwent premature senescence as marked by increased senescence-associated β-galactosidase (SA-β-Gal) staining and γH2AX-positive decidual cells. Interestingly, increased endocannabinoid signaling activated MAPK p38, but not p42/44 or mTORC1 signaling, inFaah(-/-)deciduae, and inhibition of p38 halted premature decidual senescence. We further showed that treatment of a long-acting anandamide in wild-type mice at midgestation triggered premature decidual senescence utilizing CB1, since administration of a CB1 antagonist greatly reduced the rate of PTB inFaah(-/-)females exposed to LPS. These results provide evidence that endocannabinoid signaling is critical in regulating decidual senescence and parturition timing. This study identifies a previously unidentified pathway in decidual senescence, which is independent of mTORC1 signaling. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Similar variation in carbon storage between deciduous and evergreen treeline species across elevational gradients.

PubMed

Fajardo, Alex; Piper, Frida I; Hoch, Günter

2013-08-01

The most plausible explanation for treeline formation so far is provided by the growth limitation hypothesis (GLH), which proposes that carbon sinks are more restricted by low temperatures than by carbon sources. Evidence supporting the GLH has been strong in evergreen, but less and weaker in deciduous treeline species. Here a test is made of the GLH in deciduous-evergreen mixed species forests across elevational gradients, with the hypothesis that deciduous treeline species show a different carbon storage trend from that shown by evergreen species across elevations. Tree growth and concentrations of non-structural carbohydrates (NSCs) in foliage, branch sapwood and stem sapwood tissues were measured at four elevations in six deciduous-evergreen treeline ecotones (including treeline) in the southern Andes of Chile (40°S, Nothofagus pumilio and Nothofagus betuloides; 46°S, Nothofagus pumilio and Pinus sylvestris) and in the Swiss Alps (46°N, Larix decidua and Pinus cembra). Tree growth (basal area increment) decreased with elevation for all species. Regardless of foliar habit, NSCs did not deplete across elevations, indicating no shortage of carbon storage in any of the investigated tissues. Rather, NSCs increased significantly with elevation in leaves (P < 0·001) and branch sapwood (P = 0·012) tissues. Deciduous species showed significantly higher NSCs than evergreens for all tissues; on average, the former had 11 % (leaves), 158 % (branch) and 103 % (sapwood) significantly (P < 0·001) higher NSCs than the latter. Finally, deciduous species had higher NSC (particularly starch) increases with elevation than evergreens for stem sapwood, but the opposite was true for leaves and branch sapwood. Considering the observed decrease in tree growth and increase in NSCs with elevation, it is concluded that both deciduous and evergreen treeline species are sink limited when faced with decreasing temperatures. Despite the overall higher requirements of deciduous tree species for carbon storage, no indication was found of carbon limitation in deciduous species in the alpine treeline ecotone.

Greater deciduous shrub abundance extends tundra peak season and increases modeled net CO2 uptake.

PubMed

Sweet, Shannan K; Griffin, Kevin L; Steltzer, Heidi; Gough, Laura; Boelman, Natalie T

2015-06-01

Satellite studies of the terrestrial Arctic report increased summer greening and longer overall growing and peak seasons since the 1980s, which increases productivity and the period of carbon uptake. These trends are attributed to increasing air temperatures and reduced snow cover duration in spring and fall. Concurrently, deciduous shrubs are becoming increasingly abundant in tundra landscapes, which may also impact canopy phenology and productivity. Our aim was to determine the influence of greater deciduous shrub abundance on tundra canopy phenology and subsequent impacts on net ecosystem carbon exchange (NEE) during the growing and peak seasons in the arctic foothills region of Alaska. We compared deciduous shrub-dominated and evergreen/graminoid-dominated community-level canopy phenology throughout the growing season using the normalized difference vegetation index (NDVI). We used a tundra plant-community-specific leaf area index (LAI) model to estimate LAI throughout the green season and a tundra-specific NEE model to estimate the impact of greater deciduous shrub abundance and associated shifts in both leaf area and canopy phenology on tundra carbon flux. We found that deciduous shrub canopies reached the onset of peak greenness 13 days earlier and the onset of senescence 3 days earlier compared to evergreen/graminoid canopies, resulting in a 10-day extension of the peak season. The combined effect of the longer peak season and greater leaf area of deciduous shrub canopies almost tripled the modeled net carbon uptake of deciduous shrub communities compared to evergreen/graminoid communities, while the longer peak season alone resulted in 84% greater carbon uptake in deciduous shrub communities. These results suggest that greater deciduous shrub abundance increases carbon uptake not only due to greater leaf area, but also due to an extension of the period of peak greenness, which extends the period of maximum carbon uptake. © 2015 John Wiley & Sons Ltd.

[A retrospective study of 180 cases of apical microsurgery].

PubMed

Wang, Hanguo; Li, Dan; Tian, Yu; Yu, Qing

2014-07-01

To evaluate the outcome and the potential prognostic factors of apical microsurgery. The teeth with persistent periapical diseases were treated by microsurgery using micro instruments, ultrasonic retrotips and mineral trioxide aggregate (MTA) under dental operate microscope. The procedure includes incision and flap retraction, osteotomy, apicoectomy, retro- preparation and retro- filling of root canal. Patients were recalled at 1, 3, 6, and 12- month intervals. The outcome was evaluated by clinical and radiographic examinations, and the potential prognostic factors were analyzed. One hundred and eighty cases (240 teeth), including 132 upper anterior teeth, 22 lower anterior teeth, 31 upper premolars, 18 lower premolars, 19 upper molars and 18 lower molars, were treated by microsurgery between July 2010 and December 2012. A total of 152 cases (207 teeth) were recalled. The application of the apical microsurgery included failure of previous endodontic treatment, periapical lesion with post, periapical cyst, calcified canals, separated instruments, overfilling, open apex, root facture, failure of previous apical surgery, apical fenestration, and special root canal system. The success rate was 90.8% (188/207). Age, sex, tooth position, type of periapical radiolucency, fistula and clinical application type appeared to have a negative effect on the outcome. Endo-perio lesion was a significant factor. Eighteen cases (19 teeth) failed mainly because of periodontally involved lesion and vertical root fracture. Apical microsurgery, which combines the magnification and illumination provided by the microscope with the proper use of micro instruments, can treat the teeth with persistent periapical diseases precisely and less traumatically with high success rate. Case selection and standardized operations play a key role for success.

Accuracy of 3D white light scanning of abutment teeth impressions: evaluation of trueness and precision.

PubMed

Jeon, Jin-Hun; Kim, Hae-Young; Kim, Ji-Hwan; Kim, Woong-Chul

2014-12-01

This study aimed to evaluate the accuracy of digitizing dental impressions of abutment teeth using a white light scanner and to compare the findings among teeth types. To assess precision, impressions of the canine, premolar, and molar prepared to receive all-ceramic crowns were repeatedly scanned to obtain five sets of 3-D data (STL files). Point clouds were compared and error sizes were measured (n=10 per type). Next, to evaluate trueness, impressions of teeth were rotated by 10°-20° and scanned. The obtained data were compared with the first set of data for precision assessment, and the error sizes were measured (n=5 per type). The Kruskal-Wallis test was performed to evaluate precision and trueness among three teeth types, and post-hoc comparisons were performed using the Mann-Whitney U test with Bonferroni correction (α=.05). Precision discrepancies for the canine, premolar, and molar were 3.7 µm, 3.2 µm, and 7.3 µm, respectively, indicating the poorest precision for the molar (P<.001). Trueness discrepancies for teeth types were 6.2 µm, 11.2 µm, and 21.8 µm, respectively, indicating the poorest trueness for the molar (P=.007). In respect to accuracy the molar showed the largest discrepancies compared with the canine and premolar. Digitizing of dental impressions of abutment teeth using a white light scanner was assessed to be a highly accurate method and provided discrepancy values in a clinically acceptable range. Further study is needed to improve digitizing performance of white light scanning in axial wall.

Comparative evaluation of fracture resistance of root canals obturated with four different obturating systems

PubMed Central

Punjabi, Mansi; Dewan, Ruchika Gupta; Kochhar, Rohit

2017-01-01

Aim and Objectives: The aim of this study is to evaluate and compare the fracture resistance of root canals obturated with four different obturating systems in endodontically treated teeth. Materials and Methods: One hundred and twenty single-rooted teeth were selected and decoronated at cementoenamel junction. Instrumentation of teeth (except control group) was done with Mtwo rotary files up to size 25/0.06 using a step-back technique. All teeth were divided into four experimental groups (n = 25) and two control groups (n = 10). In Group I (negative control), teeth were neither instrumented nor obturated, in Group II (positive control), instrumentation was done, but no obturation was performed, in Group III, obturation was done with cold lateral compaction technique, in Group IV, obturation was done with cold free-flow compaction technique, in Group V, obturation was done with warm vertical compaction technique, and in Group VI, obturation was done with injection-molded thermoplasticized technique. All prepared teeth were embedded in an acrylic resin block, and their fracture strength was measured using Universal Testing Machine. Statistical data were analyzed using one-way analysis of variance and Tukey's honestly significant difference test. Results: Negative control Group I showed highest fracture resistance and positive control Group II had lowest fracture resistance. Among experimental groups, cold free-flow compaction technique with GuttaFlow2 (Group IV) showed higher fracture resistance as compared to the Group III, Group V, and Group VI. Conclusion: GuttaFlow2 has the potential to strengthen the endodontically treated roots to a level that is similar to that of intact teeth. PMID:29430099

Comparative evaluation of fracture resistance of root canals obturated with four different obturating systems.

PubMed

Punjabi, Mansi; Dewan, Ruchika Gupta; Kochhar, Rohit

2017-01-01

The aim of this study is to evaluate and compare the fracture resistance of root canals obturated with four different obturating systems in endodontically treated teeth. One hundred and twenty single-rooted teeth were selected and decoronated at cementoenamel junction. Instrumentation of teeth (except control group) was done with Mtwo rotary files up to size 25/0.06 using a step-back technique. All teeth were divided into four experimental groups ( n = 25) and two control groups ( n = 10). In Group I (negative control), teeth were neither instrumented nor obturated, in Group II (positive control), instrumentation was done, but no obturation was performed, in Group III, obturation was done with cold lateral compaction technique, in Group IV, obturation was done with cold free-flow compaction technique, in Group V, obturation was done with warm vertical compaction technique, and in Group VI, obturation was done with injection-molded thermoplasticized technique. All prepared teeth were embedded in an acrylic resin block, and their fracture strength was measured using Universal Testing Machine. Statistical data were analyzed using one-way analysis of variance and Tukey's honestly significant difference test. Negative control Group I showed highest fracture resistance and positive control Group II had lowest fracture resistance. Among experimental groups, cold free-flow compaction technique with GuttaFlow2 (Group IV) showed higher fracture resistance as compared to the Group III, Group V, and Group VI. GuttaFlow2 has the potential to strengthen the endodontically treated roots to a level that is similar to that of intact teeth.

Unusual extrinsic staining following microabrasion in a girl with amelogenesis imperfecta.

PubMed

Rogers, H J; Yesudian, G; Rodd, H D

2016-08-01

Developmental defects of enamel (DDE), such as amelogenesis imperfecta (AI), may present with tooth discolouration that is of aesthetic concern to the affected individual. Children and young people with DDE may therefore seek dental interventions to improve their dental appearance. The most commonly employed approaches include microabrasion, bleaching and/or placement of composite resin veneers. A 13-year-old girl with hypomature AI requested treatment for the 'marks' on her teeth which were having a negative impact on her social interactions. Clinical examination revealed generalised dense white opacities, and a microabrasion approach was performed on 11, 12 and 13 using a commercial preparation of 6.6 % hydrochloric acid. Concerningly, the girl's father phoned the next day reporting that his daughter's teeth had turned 'orange'. An urgent review revealed that the treated teeth had indeed become an orange colour. Further enquiry found that the patient had eaten a tomato pizza immediately after her dental treatment and this was believed to have caused the severe extrinsic staining. The patient was provided with a 16 % carbamide peroxide preparation for night-time use in a laboratory-made tray. A 2-week review revealed complete resolution of the staining. Direct composite resin restorations were subsequently provided for the girl's maxillary anterior teeth to achieve an optimal cosmetic result and she has remained pleased with her dental appearance. Clinicians should be aware of the potential for extrinsic staining following microabrasion or tooth bleaching. Patients should be advised against consuming coloured food and drink for at least 48 h after their treatment.

Abstracts of Research Project Reports by National Naval Dental Center First-, Second-, and Third-Year Residents - June 1980.

DTIC Science & Technology

1980-08-30

resin ( Silar ). Extracted teeth were thermocycled at 60 and 450 C and incu- bated in a strong solution of tea. In a double-blind study, three dentists...Concise, the other with Silar . Each tooth had a control preparation and an experimental preparation. Both preparations were filled according to the...significantly I.ss than Silar . Although the initial resuits indicate that stannous fluoride applied to acid-etched enamel does not increase the

Relative growth rate in phylogenetically related deciduous and evergreen woody species.

PubMed

Antúnez, Isabel; Retamosa, Emilio C; Villar, Rafael

2001-07-01

Relative growth rate (RGR) and other growth parameters were studied in eight pairs of closely related deciduous and evergreen species (within the same genus or family). The main objective of this study was to test the association between leaf turnover rate and RGR, specific leaf area (SLA, leaf area/leaf dry weight) and other growth variables. Plants were grown for 6 months in a greenhouse under favourable water and nutrient conditions. Variation in RGR among the 16 woody species was due mainly to differences in morphological parameters such as leaf area ratio (LAR, whole plant area/whole plant dry weight) and SLA). However, temporal variation in RGR within species was due mainly to variation in net assimilation rate. When phylogeny was not taken into account, analyses showed that deciduous species grew faster than evergreens. In contrast, when phylogeny was taken into account, the data analysis showed that a faster RGR is not consistently associated with the deciduous habit (in five pairs it was, but in the other three it was not). The faster growth of the deciduous trees (in the five positive contrasts) could be explained by their higher LAR and higher SLA relative to evergreens. The lack of differences in RGR between deciduous and evergreens (in three pairs) was due to the higher leaf mass ratio (LMR, leaf dry biomass/total dry biomass) for the evergreens, which offset the higher SLA of the deciduous species, resulting in a similar LAR in both functional groups (LAR=LMR×SLA). Deciduous species had consistently higher SLA than evergreens. We suggest that SLA, more than RGR, could be an important parameter in determining adaptive advantages of deciduous and evergreen species.

Comparison of Single Visit Post Endodontic Pain Using Mtwo Rotary and Hand K-File Instruments: A Randomized Clinical Trial.

PubMed

Kashefinejad, Mohamad; Harandi, Azade; Eram, Saeed; Bijani, Ali

2016-01-01

Pain is an unpleasant outcome of endodontic treatment that can be unbearable to patients. Instrumentation techniques may affect the frequency and intensity of post-endodontic pain. This study aimed to compare single visit post endodontic pain using Mtwo (NiTi) rotary and hand K-file instruments. In this randomized controlled trial, 60 teeth with symptomatic irreversible pulpitis in 53 patients were selected and randomly assigned into two groups of 30 teeth. In group A, the root canals were prepared with Mtwo (NiTi) rotary instruments. In group B, the root canals were prepared with hand K-file instruments. Pain assessment was implemented using visual analog scale (VAS) at four, eight, 12 and 24 hours after treatment. The acquired data were analyzed using chi-square, Mann-Whitney U and Student's t-test (P<0.05). Patients treated with rotary instruments experienced significantly less post-endodontic pain than those treated with hand instruments (P<0.001). The use of Mtwo (NiTi) rotary instruments in root canal preparation contributed to lower incidence of postoperative pain than hand K-files.

Zinc and magnesium in the uterus of the pregnant and pseudopregnant mouse and the effects of Mg2+ ions on uterine alkaline phosphatase.

PubMed

Buxton, L E; Murdoch, R N

1981-01-01

The levels of zinc and magnesium in the mouse uterus during early pregnancy and pseudopregnancy were determined using atomic absorption spectroscopy techniques. The total zinc and magnesium content of the uterus increased between days 5 and 12 of pregnancy and between days 5 and 9 of content of the pseudopregnancy when decidual cells were present. However, the metals were not accumulated at a rate sufficient to match increases in uterine weight and constant concentrations (micrograms of metals per gram wet weight ot tissue) were not maintained over the various reproductive stages studied. The accumulation of the metals was associated with the presence of decidual cells, and non-decidualized horns of pseudopregnant mice failed to increase their total content of zinc and magnesium between days 5 and 9. The magnesium content of each uterus was usually between 5- and 13-fold greater than the total zinc content. mg2+ in low concentration (0-2mM) stimulated both the pyrophosphatase and orthophosphatase activities of purified preparations of the mouse uterine metalloenzyme, alkaline phosphatase. Higher concentrations (up to 8 mM) of the cation decreased pyrophosphatase activity but did not alter orthophosphatase activity. Mg/+ was more effective, however, in increasing the orthophosphatase activity of the enzyme and its stimulating effects in this case were greater in carbonate-bicarbonate buffer than in glycine-NaOH buffer. Mg2+ did not significantly influence apparent Km values or the response of the enzyme to changes in temperature. Zn2+, however, was required to maintain the stability of alkaline phosphatase apoenzyme preparations. It was concluded that during normal pregnancy and pseudopregnancy zinc and magnesium would always be present in amounts considerably greater than those required to saturate alkaline phosphatase for full catalytic activity. Thus, while the metals exert major effects on the activity and stability of the enzyme in vitro, they may not be major factors involved in the in utero regulation of the enzyme during early pregnancy.

Comparative evaluation of fracture resistance under static and fatigue loading of endodontically treated teeth restored with carbon fiber posts, glass fiber posts, and an experimental dentin post system: an in vitro study.

PubMed

Ambica, Khetarpal; Mahendran, Kavitha; Talwar, Sangeeta; Verma, Mahesh; Padmini, Govindaswamy; Periasamy, Ravishankar

2013-01-01

This investigation sought to compare the fracture resistance under static and fatigue loading of endodontically treated teeth restored with fiber-reinforced composite posts and experimental dentin posts milled from human root dentin by using computer-aided design/computer-aided manufacturing. Seventy maxillary central incisors were obturated and divided into 4 groups: control group without any post (n = 10), carbon fiber post group (n = 20), glass fiber post group (n = 20), and dentin post group (n = 20). Control group teeth were prepared to a height of 5 mm. In all other teeth, post space was prepared; a post was cemented, and a core build-up was provided. Half the samples from each group were statistically loaded until failure, and the remaining half were subjected to cyclic loading, followed by monostatic load until fracture. One-way analysis of variance and Bonferroni multiple comparisons revealed a significant difference among test groups. The control group demonstrated highest fracture resistance (935.03 ± 33.53 N), followed by the dentin post group (793.12 ± 33.69 N), glass fiber post group (603.44 ± 46.67 N), and carbon fiber post group (497.19 ± 19.27 N) under static loading. These values reduced to 786.69 ± 29.64 N, 646.34 ± 26.56 N, 470 ± 36.34 N, and 379.71 ± 13.95 N, respectively, after cyclic loading. Results suggest that human dentin can serve as post material under static and fatigue loading. Although at an early stage in research, the use of dentin posts in root-filled teeth looks promising. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Effects of different preparation procedures during tooth whitening on enamel bonding.

PubMed

Wilson, Dustin; Xu, Changqi; Hong, Liang; Wang, Yong

2009-04-01

The objective of this study was to assess effects of some clinically related preparation procedures during tooth whitening on enamel bonding properties. Sixty-two extracted human teeth were cleaned and divided into four groups. Forty-two of the teeth were left with their natural surface intact while 20 teeth were polished to form a flat surface. Half of the tooth served as the experimental side and received one of the two whitening products: Opalescence (10% carbamide peroxide) and Crest Whitestrips (6.5% hydrogen peroxide), for 2 weeks. Post-bleaching intervals included: 1 day, 1 week, and 2 weeks. On these days, tooth (10 mm x 1.5 mm x 1.5 mm) sections were evaluated using Raman spectroscopy, scanning electron microscopy and tensile bond strength tests. T-test, ANOVA test, and mixed model regression analysis were used to assess the differences. No significant difference existed between natural surface and polished surface teeth for all groups at both Day One and Week Two (P > 0.05). On Day One, both treated groups had significant lower bond strength than the control group (P = 0.002). After 2 weeks, no significant difference existed between any group (P = 0.381). SEM indicated that resin-enamel interfaces in bleached enamel exhibited more defects in granular formations when compared to the control. Raman results indicated a lower degree of polymerization (DP) of adhesive at the interface for treated teeth surfaces. In summary, pre-bleaching surface treatments such as polish or non-polish, had no effect on bond strength. Bleaching significantly decreased bond strength initially, but after 2 weeks, bleaching had no significant effect on bond strength. Storage time had significant effect on Opalescence treated enamel, but not on control and Whitestrip treated enamel. The decrease of bond strength may be related to interfacial defects and low DP due to oxygen release after bleaching.

Fracture patterns of glass-ionomer cement overlays versus stainless steel bands during endodontic treatment: an ex-vivo study.

PubMed

Pakdeethai, S; Abuzar, M; Parashos, P

2013-12-01

To compare fracture patterns of posterior teeth temporized with: mesio-occlusal-distal (MOD) glass-ionomer cement (GIC) interim restorations, stainless steel (SS) bands, GIC dome overlays and GIC dome overlays with occlusal temporary restorations. The root canals of 92 extracted human premolars and molars were prepared with rotary NiTi instruments and dressed with calcium hydroxide paste prior to cavity preparation for standardized MOD restorations. Teeth were divided into four groups (n = 23) and temporarily restored with: GIC interim restorations (GIC group), stainless steel bands (SS group), GIC dome overlays (GIC-O group) or GIC dome overlays with intermediate restorative material (IRM) in the access cavities (GIC-IRM group). Teeth were subjected to compressive axial load until fracture; fracture forces and fracture modes were recorded. Statistical analysis included Kaplan-Meier plots, Cox proportional hazards model, one-way analysis of variance, chi-square and Fisher's exact tests. There was a significantly higher risk of failure in the GIC group compared with the SS (P < 0.001), GIC-O (P < 0.001) and GIC-IRM (P = 0.001) groups. The mean fracture force for SS was significantly higher than GIC-O (P = 0.03) and GIC-IRM (P < 0.001). GIC fracture force was significantly lower than all other groups (P < 0.001). Significantly fewer unfavourable fractures were observed in SS compared with GIC (P = 0.001), GIC-O (P = 0.007) and GIC-IRM (P < 0.001). Glass-ionomer cement dome overlays with reduced cuspal height and occlusal inclines may be recommended for broken-down posterior teeth, without any risk of poor aesthetics, gingival irritation or further proximal tooth structure loss. Stainless steel bands may only need to be used in extensively broken-down teeth or in the presence of parafunctional habits. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Uterine NDRG2 expression is increased at implantation sites during early pregnancy in mice, and its down-regulation inhibits decidualization of mouse endometrial stromal cells.

PubMed

Gu, Yan; Zhang, Xuan; Yang, Qian; Wang, Jian-mei; He, Ya-ping; Sun, Zhao-gui; Zhang, Hui-qin; Wang, Jian

2015-05-27

N-myc down-regulated gene 2 (NDRG2) is a tumor suppressor involved in cell proliferation and differentiation. The aim of this study was to determine the uterine expression pattern of this gene during early pregnancy in mice. Uterine NDRG2 mRNA and protein expression levels were determined by RT-PCR and Western blot analyses, respectively, during the peri-implantation period in mice. Immunohistochemical (IHC) analysis was performed to examine the spatial localization of NDRG2 expression in mouse uterine tissues. The in vitro decidualization model of mouse endometrial stromal cells (ESCs) was used to evaluate decidualization of ESCs following NDRG2 knock down by small interfering RNA (siRNA). Statistical significance was analyzed by one-way ANOVA using SPSS 19.0 software. Uterine NDRG2 gene expression was significantly up-regulated and was predominantly localized to the secondary decidual zone on days 5 and 8 of pregnancy in mice. Its increased expression was associated with artificial decidualization as well as the activation of delayed implantation. Furthermore, uterine NDRG2 expression was induced by estrogen and progesterone treatments. The in vitro decidualization of mouse ESCs was accompanied by up-regulation of NDRG2 expression, and knock down of its expression in these cells by siRNA inhibited the decidualization process. These results suggest that NDRG2 might play an important role in the process of decidualization during early pregnancy.

Does endodontic post space irrigation affect smear layer removal and bonding effectiveness?

PubMed

Gu, Xin-Hua; Mao, Cai-Yun; Liang, Cong; Wang, Hui-Ming; Kern, Matthias

2009-10-01

The effect of different post space irrigants on smear layer removal and dentin bond strength was evaluated. Sixty-six extracted sound maxillary central incisors were endodontically treated. After post space preparation, the teeth were assigned to three groups of 22 teeth each. The teeth of these three groups were irrigated for 1 min with 17% ethylenediaminetetracetic acid (EDTA) (group 1), 5.25% sodium hypochlorite (NaOCl) (group 2), or 0.9% sodium chloride (NaCl) (group 3). In each group, eight specimens were split longitudinally for smear layer evaluation, and the other fourteen specimens were filled with a self-etching adhesive system (Panavia F). Four of 14 specimens of each group were prepared for evaluation of the resin-dentin interdiffusion zone (RDIZ) and resin tags, and the other 10 specimens were serially sectioned for push-out test analysis. Smear layer removal and bond strength were affected by different post space irrigants. EDTA removed the smear layer extremely effectively and, as a result, improved the bond strength at each region (apical, middle, and coronal) of the roots. Resin tag formation and the RDIZ were also affected by different irrigants and in accordance with bond strength. Therefore, removal of the smear layer use a self-etching luting system plays an important role in bonding effectiveness.

Comparison of the cleaning capacity of Mtwo and Pro Taper rotary systems and manual instruments in primary teeth

PubMed Central

Azar, Mohammad Reza; Safi, Laya; Nikaein, Afshin

2012-01-01

Background: Root canal cleaning is an important step in endodontic therapy. In order to develop better techniques, a new generation of endodontic instruments has been designed. The aim of this study was to compare the effectiveness of manual K-files (Mani Co, Tokyo, Japan) and two rotary systems–Mtwo (Dentsply-Maillefer, Ballaigues, Switzerland) and ProTaper (VDW, Munich, Germany)–for root canal preparation in primary molars. Materials and Methods: India ink was injected to 160 mesiobuccal and distal root canals of mandibular primary molars. The teeth were randomly divided into three experimental groups and one control group. In each experimental group, either manual instruments (K-files) or rotary instruments (Mtwo or ProTaper) were used to prepare root canals. After cleaning the canals and clearing the teeth, ink removal was evaluated with a stereomicroscope. Statistical analysis was done with Kruskal–Wallis and Friedman tests. Results: There were no significant differences in cleaning efficiency between manual and rotary instruments. Only ProTaper files performed significantly better in the coronal and middle thirds than in the apical third of the root canal. Conclusion: Manual K-files and the Mtwo and ProTaper rotary systems showed equally acceptable cleaning ability in primary molar root canals. PMID:22623929

Comparative evaluation of microleakage of various retrograde filling materials: An in vitro study.

PubMed

Galhotra, Virat; Sofat, Anjali; Pandit, Inder K; Gambhir, Ramandeep Singh; Srivastava, Nikhil; Gugnani, Neeraj

2013-07-01

The present study is envisaged to evaluate and compare the microleakage of mineral trioxide aggregate (MTA) with commonly used retrograde filling materials, like light-cured composite with dentin-bonding agents, light-cured glass ionomer cement (LC GIC) and resin-modified zinc oxide eugenol. Ninety freshly extracted non-carious single-rooted human anterior teeth were used in the study. They were randomly divided into four experimental groups and two control groups of 15 each. Following the biomechanical preparation, all teeth were obturated and then the apices of the obturated teeth were resected by removing 3 mm of each apex at 90° to the long axis of the tooth with a straight fissure bur in a high-speed air-rotor handpiece with water coolant. A 3-mm-deep root end cavity was prepared and the root end fillings were placed as per the manufacturer's instructions and according to the groups divided. The samples were then immersed in 1% methylene blue at room temperature for 72 h, 96 h and 1 week and the dye penetration was measured. All the four materials used in the study showed some microleakage throughout the experimental period. The sealing ability in terms of microleakage can be summarized as: MTA > Composite resin with dentin bonding agent > LC GIC > Resin modified zinc oxide eugenol.

Evaluation of time required for recontamination of coronally sealed canals medicated with calcium hydroxide and chlorhexidine.

PubMed

Gomes, B P F A; Sato, E; Ferraz, C C R; Teixeira, F B; Zaia, A A; Souza-Filho, F J

2003-09-01

To determine in vitro the time required for recontamination of coronally sealed canals medicated with either calcium hydroxide (CaOH2), 2% chlorhexidine gel (CG) or with a combination of both. Eighty intact, caries-free, premolar teeth with straight roots and mature apices were selected for the study. After biomechanical preparation of 75 teeth, they were randomly divided into nine groups according to the intracanal medicament and the coronal seal with 'Intermediate Restorative Material' (IRM) as follows: (i) 10 teeth medicated with CG, coronally unsealed; (ii) 10 teeth medicated with CaOH2, coronally unsealed; (iii) 10 teeth medicated with CaOH2 + CG, coronally unsealed; (iv) 10 teeth medicated with CG + coronal seal; (v) 10 teeth medicated with CaOH2 + coronal seal; (vi) 10 teeth medicated with CG + CaOH2 + coronal seal; (vii) 10 teeth without intracanal medicament and coronally sealed; (viii) 5 teeth without intracanal medicament and coronally unsealed, used as the positive control group (PC); (ix) 5 teeth with intact crowns used as the negative control group (NC). Glass flasks were filled with Brain Heart Infusion broth (BHI), so that only the root apex was in contact with the broth, while the crown was immersed in human saliva + BHI (3:1). The flasks were then incubated at 37 degrees C in an atmosphere of 10% CO2, and microbial growth was checked daily. All specimens of the PC showed contamination within 1 day of incubation, while the NC showed no evidence of broth turbidity. Recontamination was detected after an average time of 3.7 days in the unsealed canals medicated with CG, 1.8 days in the group medicated with CaOH2 and 2.6 days in the group medicated with CaOH2 + CG. When the crowns were sealed with IRM, recontamination was detected within 13.5 days in the canals medicated with CG, after 17.2 days in the group medicated with CaOH2 and after 11.9 days in the group medicated with CG + CaOH2. The group with no medication, but sealed with IRM, showed recontamination after 8.7 days. There were statistically significant differences between the teeth with or without coronal seal (P<0.05). The coronal seal delayed but did not prevent leakage of microorganisms. There was no difference between the various medicaments.

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

PubMed

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

2013-01-01

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

Three-dimensional evaluation of effectiveness of hand and rotary instrumentation for retreatment of canals filled with different materials.

PubMed

Hammad, Mohammad; Qualtrough, Alison; Silikas, Nick

2008-11-01

The aim of this study was to measure the remaining filling volume of different obturation materials from root-filled extracted teeth by using 2 removal techniques. Eighty single-rooted teeth were collected and decoronated, and the root canal was prepared by using the ProTaper nickel-titanium rotary files. The teeth were randomly allocated into 4 groups, and each group was obturated by using a different material. Group 1 was filled with gutta-percha and TubliSeal sealer, group 2 was filled with EndoRez points and EndoRez sealer, group 3 was filled with RealSeal points and RealSeal sealer, and Group 4 was filled with a gutta-percha point and GuttaFlow sealer. Teeth were scanned with a micro-computed tomography scan, and then root fillings were removed by using ProTaper retreatment files or hand K-files. Teeth were scanned again, and volume measurements were carried out with micro-computed tomography software. Statistical analysis showed significant differences between the 2 removal techniques for gutta-percha and for both techniques between gutta-percha and the other groups. The present study showed that all tested filling materials were not completely removed during retreatment by using hand or rotary files. Gutta-percha was more efficiently removed by using hand K-files.

Root canal preparation in endodontics: conventional versus laser methods

NASA Astrophysics Data System (ADS)

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

1992-06-01

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

An in vitro evaluation of the integrity of stainless steel crown margins cemented with different luting agents.

PubMed

Ettinger, R L; Kambhu, P P; Asmussen, C M; Damiano, P C

1998-01-01

The elderly population is retaining more teeth which require extensive restorations. The purpose of this study was to identify a luting agent which had the least marginal breakdown when used with stainless steel crowns. Thirty-six caries-free molars were selected, prepared for stainless steel crowns, and embedded in acrylic to support the crown and tooth. The crowns (Unitek/3M) were cemented with 4 different luting agents: (A) Fleck's Cement, (B) Ketac-Cem, (C) All-Bond C & B Cement, and (D) Panavia EX Cement. All the restored teeth were thermocycled and divided into 3 experimental groups. Twelve teeth were stained. The remaining teeth were occlusally loaded and stained. The remaining 12 teeth were thermocycled and stained again. The stainless steel crowns were then sectioned and photographed at 7.5x mag. The dye penetration was evaluated by measurement of the percentage of dye penetration from the crown margin to the cusp tip on each side. Statistical analysis found that the least dye penetration was with All-Bond C & B Cement (p = 0.0001). The most extensive penetration was observed in Ketac-Cem Occlusal loading was a significant factor (p = 0.0001) increasing the dye penetration, but the crown-tooth gap was not.

Effectiveness of Rotary Endodontic Instruments on Smear Layer Removal in Root Canals of Primary Teeth: A Scanning Electron Microscopy Study.

PubMed

Subramaniam, Priya; Girish Babu, K L; Tabrez, T A

2016-01-01

The present SEM study was undertaken to evaluate the effect of root canal instrumentation using both manual and rotary files in the root canals of primary anterior teeth. Thirty freshly extracted primary maxillary incisors were divided into 3 groups of 10 teeth each. In Group I, root canals were instrumented with rotary NiTi files; in Group II, the root canals were instrumented using manual NiTi K files and; in Group III, manual instrumentation was done with stainless steel K files. Longitudinal sections were prepared and processed for observation under SEM at the coronal, middle and apical thirds. Scoring of smear layer was done according to Hulsmann and the data obtained was subjected to statistical analysis. Rotary files cleaned the coronal and middle thirds of root canals more effectively. Statistically there was no significant difference between the groups. Lowest score of 2.6 in the apical third of root canals was seen with hand NiTi files. Rotary instrumentation was as effective as manual instrumentation in removal of smear layer in the root canals of primary anterior teeth.

AMS-14C analysis of modern teeth: A comparison between two sample preparation techniques

NASA Astrophysics Data System (ADS)

Solis, C.; Solis-Meza, E.; Morales, M. E.; Rodriguez-Ceja, M.; Martínez-Carrillo, M. A.; Garcia-Calderon, D.; Huerta, A.; Chávez, E.

2017-09-01

AMS-14C analysis of modern teeth has become important for forensic studies. 14C content in human teeth reflects the 14C atmospheric concentration during its formation and allows the calculation of the actual year of birth. Through AMS, it is possible to measure the 14C concentrations in a tissue with high precision. However, there is a debate about which should be the best fraction for teeth carbon dating: collagen or enamel. This work focuses on the results obtained from enamel and collagen extracted from Mexican people in order to compare them. Collagen from dental pieces donated from people older than 60-years-old have been included to understand the turnover process and usefulness of collagen to determine the date of birth. Our results indicate that when a single dental piece is available, enamel method allows the determination of the tooth formation date. Dating collagen of the same tooth helps to discriminate if the formation date belongs to the left or the right side of the peak bomb, but also corroborates, the ages obtained through enamel analysis.

Surgical management of vertical root fractures for posterior teeth: report of four cases.

PubMed

Floratos, Spyros G; Kratchman, Samuel I

2012-04-01

The objective of this article was to present a surgical treatment option for teeth with incomplete vertical root fracture in maxillary and mandibular posterior teeth. Four cases are presented in which 1 endodontically treated maxillary or mandibular molar had an incomplete vertical root fracture involving 1 of the roots. The tooth underwent a flap elevation procedure to visualize the pattern of bone loss and assess the extent of root fracture. The fracture line was eliminated by resecting the root in a beveled manner, after which root-end preparation and root-end filling were performed by using mineral trioxide aggregate. The osteotomy was covered with an absorbable collagen membrane. Cases were followed up for 8-24 months after surgery. The procedure was shown to be predictable and successful in this series. Root length was preserved, and tooth extraction was avoided. The microsurgical treatment option for multirooted teeth with incomplete vertical root fracture resulted in long-term clinical success. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

[Three-dimensional computer aided design for individualized post-and-core restoration].

PubMed

Gu, Xiao-yu; Wang, Ya-ping; Wang, Yong; Lü, Pei-jun

2009-10-01

To develop a method of three-dimensional computer aided design (CAD) of post-and-core restoration. Two plaster casts with extracted natural teeth were used in this study. The extracted teeth were prepared and scanned using tomography method to obtain three-dimensional digitalized models. According to the basic rules of post-and-core design, posts, cores and cavity surfaces of the teeth were designed using the tools for processing point clouds, curves and surfaces on the forward engineering software of Tanglong prosthodontic system. Then three-dimensional figures of the final restorations were corrected according to the configurations of anterior teeth, premolars and molars respectively. Computer aided design of 14 post-and-core restorations were finished, and good fitness between the restoration and the three-dimensional digital models were obtained. Appropriate retention forms and enough spaces for the full crown restorations can be obtained through this method. The CAD of three-dimensional figures of the post-and-core restorations can fulfill clinical requirements. Therefore they can be used in computer-aided manufacture (CAM) of post-and-core restorations.

The Efficacy of Buccal Infiltration of 4% Articaine and PSA Injection of 2% Lidocaine on Anesthesia of Maxillary Second Molars.

PubMed

Maljaei, Ensiyeh; Pourkazemi, Maryam; Ghanizadeh, Milad; Ranjbar, Rana

2017-01-01

During the early mixed dentition period, the location of the deciduous maxillary second molar results in ineffectiveness of the infiltration technique in this area. In such cases, administration of posterior superior alveolar (PSA) nerve block is recommended; however, such a technique has some complications. The present study was undertaken to compare the effects of buccal infiltration of 4% Articaine and PSA technique with 2% Lidocaine on the success of anesthesia of maxillary deciduous second molars in 6 to 9-year old children. In the present double-blind randomized clinical trial, 56 children aged 6-9 years requiring vital pulp therapy of deciduous maxillary second molar were included. In group 1, 4% Articaine was injected using a buccal infiltration technique. In group 2, 2% Lidocaine was injected using the PSA nerve block technique. After 10 min, the caries was removed and access cavity preparation was instituted. The patients were asked to report the presence or absence of pain during the procedure. Therefore, the existence of pain was measured by the patient's self-report. Data were analyzed with descriptive statistical methods and the chi -squared test. Pain was reported by 6 (21.4%) and 9 (32.1%) subjects in the Articaine and Lidocaine groups, respectively. Chi -squared test did not reveal any significant differences between the two groups ( P =0.54). Under the limitations of the present study, there was no significant differences between the results of Articaine buccal infiltration and Lidocaine PSA technique, so Articaine buccal infiltration can be used as a substitute for the PSA technique.

A comparison between red and infrared light for recording pulpal blood flow from human anterior teeth with a laser Doppler flow meter.

PubMed

Kijsamanmith, Kanittha; Timpawat, Siriporn; Vongsavan, Noppakun; Matthews, Bruce

2011-06-01

To compare red (635 nm) and infrared (780 nm) light for recording pulpal blood flow from human anterior teeth with a laser Doppler flow meter. Recordings were made from 7 healthy teeth in 5 subjects (aged 22-55 years) using a laser Doppler flow meter (Periflux 4001) equipped with both red and infrared lasers. Average blood flow signals were obtained with both light sources alternately from each tooth under five conditions: intact tooth without opaque rubber dam, intact tooth with dam, after injecting local anaesthetic (3% Mepivacaine) (LA) over the apex of the tooth and cavity preparation to almost expose the pulp, after removal and replacement of the pulp, and with the root canal empty. With infrared light, because of technical limitations, data were obtained for the first three conditions only. The dam significantly decreased the mean blood flow by 82%. Injecting LA and cavity preparation had no significant effect. With red light, dam produced a decrease of 56%, and the resulting signal was reduced by 33% after LA and cavity preparation. The remaining signal fell by 46% after pulp removal and replacement. This contribution of the pulp is similar to that recorded previously with infrared light. There was no significant further change when the pulp was finally removed. The importance of using opaque rubber dam is confirmed. With dam, there is no advantage to using red rather than infrared light, and in each case the pulp contributes less than 50% to the blood flow signal. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effect of reciprocating file motion on microcrack formation in root canals: an SEM study.

PubMed

Ashwinkumar, V; Krithikadatta, J; Surendran, S; Velmurugan, N

2014-07-01

To compare dentinal microcrack formation whilst using Ni-Ti hand K-files, ProTaper hand and rotary files and the WaveOne reciprocating file. One hundred and fifty mandibular first molars were selected. Thirty teeth were left unprepared and served as controls, and the remaining 120 teeth were divided into four groups. Ni-Ti hand K-files, ProTaper hand files, ProTaper rotary files and WaveOne Primary reciprocating files were used to prepare the mesial canals. Roots were then sectioned 3, 6 and 9 mm from the apex, and the cut surface was observed under scanning electron microscope (SEM) and checked for the presence of dentinal microcracks. The control and Ni-Ti hand K-files groups were not associated with microcracks. In roots prepared with ProTaper hand files, ProTaper rotary files and WaveOne Primary reciprocating files, dentinal microcracks were present. There was a significant difference between control/Ni-Ti hand K-files group and ProTaper hand files/ProTaper rotary files/WaveOne Primary reciprocating file group (P < 0.001) with ProTaper rotary files producing the most microcracks. No significant difference was observed between teeth prepared with ProTaper hand files and WaveOne Primary reciprocating files. ProTaper rotary files were associated with significantly more microcracks than ProTaper hand files and WaveOne Primary reciprocating files. Ni-Ti hand K-files did not produce microcracks at any levels inside the root canals. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Incidence of Apical Crack Initiation during Canal Preparation using Hand Stainless Steel (K-File) and Hand NiTi (Protaper) Files.

PubMed

Soni, Dileep; Raisingani, Deepak; Mathur, Rachit; Madan, Nidha; Visnoi, Suchita

2016-01-01

To evaluate the incidence of apical crack initiation during canal preparation with stainless steel K-files and hand protaper files (in vitro study). Sixty extracted mandibular premo-lar teeth are randomly selected and embedded in an acrylic tube filled with autopolymerizing resin. A baseline image of the apical surface of each specimen was recorded under a digital microscope (80×). The cervical and middle thirds of all samples were flared with #2 and #1 Gates-Glidden (GG) drills, and a second image was recorded. The teeth were randomly divided into four groups of 15 teeth each according to the file type (hand K-file and hand-protaper) and working length (WL) (instrumented at WL and 1 mm less than WL). Final image after dye penetration and photomicrograph of the apical root surface were digitally recorded. Maximum numbers of cracks were observed with hand protaper files compared with hand K-file at the WL and 1 mm short of WL. Chi-square testing revealed a highly significant effect of WL on crack formation at WL and 1 mm short of WL (p = 0.000). Minimum numbers of cracks at WL and 1 mm short of WL were observed with hand K-file and maximum with hand protaper files. Soni D, Raisingani D, Mathur R, Madan N, Visnoi S. Incidence of Apical Crack Initiation during Canal Preparation using Hand Stainless Steel (K-File) and Hand NiTi (Protaper) Files. Int J Clin Pediatr Dent 2016;9(4):303-307.

Effects of three oral analgesics on postoperative pain following root canal preparation: a controlled clinical trial.

PubMed

Mehrvarzfar, P; Abbott, P V; Saghiri, M A; Delvarani, A; Asgar, K; Lotfi, M; Karamifar, K; Kharazifard, M J; Khabazi, H

2012-01-01

  To compare the effects of single doses of three oral medications on postoperative pain following instrumentation of root canals in teeth with irreversible pulpitis.   In this double-blind clinical trial, 100 patients who had anterior or premolar teeth with irreversible pulpitis without any signs and symptoms of acute or chronic apical periodontitis and moderate to severe pain were divided by balanced block random allocation into four groups of 25 each, a control group receiving a placebo medication, and three experimental groups receiving a single dose of either Tramadol (100 mg), Novafen (325 mg of paracetamol, 200 mg ibuprofen and 40 mg caffeine anhydrous) or Naproxen (500 mg) immediately after the first appointment where the pulp was removed, and the canals were fully prepared. The intensity of pain was scored based on 10-point VAS before and after treatment for up to 24 h postoperatively. Data were submitted to repeated analysis of variance.   At the 6, 12 and 24 h postoperative intervals after drug administration, the intensity of pain was significantly lower in the experimental groups than in the placebo group (P < 0.01). Tramadol was significantly less effective (P < 0.05) than Naproxen, and Novafen that were similar to each other (P > 0.05).   A single oral dose of Naproxen, Novafen and Tramadol taken immediately after treatment reduced postoperative pain following pulpectomy and root canal preparation of teeth with irreversible pulpitis. © 2011 International Endodontic Journal.

Apical Extrusion of Intracanal Bacteria with Single File and Multifile Rotary Instrumentation Systems.

PubMed

Saberi, Eshaghali; Zahedani, Shahram Shahraki; Ebrahimipour, Sediqe

2017-01-01

Instrumentation techniques may cause extrusion of microorganisms and their products into the periapical region resulting inflammation and treatment failure. The aim of this ex vivo study was comparing the apical bacterial extrusion in canals prepared with single file versus multiple file rotary systems. Ninety-two human single-rooted mandibular first premolars were used. Endodontic access cavities were prepared, and root canals were contaminated with an Enterococcus faecalis ( E. faecalis ) suspension. The samples were incubated at 37°C for 30 days; the contaminated teeth were divided into four groups of 20 specimens each (1: Reciproc, 2: Mtwo, 3: Neoniti A1, 4: Safesider). Six teeth were not infected and each were prepared with one of the above instruments were considered as negative and six teeth which had been previously infected, were used as positive control groups. Extruded bacteria from the apical foramen during instrumentation were collected into vials containing 0.9% NaCl. The microbial samples were taken from the vials and incubated in brain heart agar medium for 24 h. The resulting bacterial titer, in colony-forming units per mL, was determined. The data entered into SPSS 18 software and were analyzed by Kruskal-Wallis and Mann-Whitney U-tests at 0.05 significance level. Mtwo multifile system showed significantly less bacterial extrusion than Safesider ( P = 0.015) and Neoniti A1 ( P = 0.042) but did not show significant difference with Reciproc system ( P = 0.25). All instrumentation systems extruded bacteria beyond the apical foramen. However, this study showed that Mtwo multifile rotary system extruded fewer bacteria.

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

In vitro evaluation of microleakage under a glass ionomer surface protector cement after different enamel treatment procedures.

PubMed

Haznedaroglu, Eda; Mentes, Ali R; Tanboga, Iknur

2012-03-01

The aim of this in vitrostudy was to evaluate the microleakage of a glass-ionomer surface-protector cement (GC Fuji Triage) placed onto the fissure surfaces of extracted human molars prepared using six different treatment procedures. Ninety-six extracted non-carious human molar teeth were divided into five enamel treatment groups: (Gp1) air-abraded (Micadent II, Medidenta); (Gp2) air-abraded and conditioned with 10% polyacrylic acid (GC dentin conditioner); (Gp3) prepared by a bur designed for enameloplasty (#8833 Komet); (Gp4) prepared with a bur and conditioned; (Gp5) conditioned; and (Gp6) no treatment (control). The teeth were then sealed with GC Fuji Triage. The teeth were thermocycled and left in distilled water or artificial saliva for one week, coated twice with nail varnish, and stained in a dye. They were sectioned and scored for microleakage. All groups showed microleakage. Samples that were kept in saliva had better results than those that were kept in distilled water (P<0.05). Samples conditioned before the treatment were also better than non-conditioned groups (P<0.05). In distilled water and artificial saliva, the range of the groups was, from the best, Gp2

Changing patterns in coastal cutthroat trout (Oncorhynchus clarki clarki) diet and prey in a gradient of deciduous canopies

USGS Publications Warehouse

Romero, N.; Gresswell, R.E.; Li, J.L.

2005-01-01

We examined the influence of riparian vegetation patterns on coastal cutthroat trout Oncorhynchus clarki clarki diet and prey from the summer of 2001 through the spring of 2002. Benthic and drifting invertebrates, allochthonous prey, and fish diet were collected from deciduous, conifer, and mixed sections of three Oregon coastal watersheds. The nine sites were best characterized as a continuum of deciduous cover, and shrub cover and proportion of deciduous canopy were positively correlated (r = 0.74). Most sources of prey (benthic invertebrate biomass, allochthonous invertebrate inputs, aquatic and total invertebrate drift) and aquatic prey ingested by coastal cutthroat trout were greater where shrub cover was more abundant. Only aquatic drift, total invertebrate drift, and allochthonous invertebrates were positively correlated with deciduous vegetation. Compared with coniferous sites, allochthonous invertebrates under deciduous and mixed canopies were almost 30% more abundant. Stream discharge likely influenced seasonal fluxes of aquatic invertebrate biomass in the benthos and drift. Aquatic insects dominated gut contents during this study; however, terrestrial prey were most common in the diet during the summer and fall. In the Pacific northwest, systematic removal of deciduous riparian vegetation to promote conifers may have unintended consequences on food resources of coastal cutthroat trout and aquatic food web interactions. ?? 2005 NRC.