Knowledge of Emergency Physicians about the Management of Traumatic Dental Injuries: A Cross-sectional Study in Northern Iran.

Background: Dental trauma is a common dental public health problem among the children and adults. As the emergency departments are usually the first contact point for patients after a trauma, this study aimed to evaluate the level of knowledge of emergency medicine specialists or residents and general practitioners (GPs) working in the emergency departments about the management of traumatic dental injuries. Methods: In this descriptive cross-sectional study, all emergency medicine specialists or residents and GPs working in the emergency department of hospitals affiliated to Mazandaran University of Medical Sciences were evaluated. Data were collected using a questionnaire comprising questions on demographic information and physicians' knowledge of how to deal and manage different dental injuries. The information was analyzed using t-test and chi-square statistical test. Results: The level of knowledge was good in 71.5% of emergency medicine specialists and average in 75% of the residents and 93.4% of GPs. None of the participants had low level of knowledge about management of traumatic dental injuries. There was a statistically significant association between physicians' knowledge and their job position (P<0.001). Moreover, there were no statistically significant differences between gender and the history of participating in dental trauma courses with the level of physicians' knowledge (P>0.05). Conclusion: The results of present study highlights the need for training programs to raise the knowledge of emergency medicine residents and GPs about how to effectively manage the traumatic dental injuries in patients presenting to the emergency department.

The effect of different pulp-capping materials on proliferation, migration and cytokine secretion of human dental pulp stem cells.

OBJECTIVES: Biocompatibility of dental biomaterials plays a critical role in regeneration of dental stem cells. The aim of present study was to evaluate the effects of novel biomaterials of TheraCal-LC (TheraCal; Bisco), Angelus mineral trioxide aggregate (MTA; Angelus), calcium-enriched mixture (CEM; BioniqueDent), and Biodentine (Septodont) on viability of human dental pulp stem cells (hDPSCs). Moreover, the recruitment of dental pulp stem cells is a prerequisite for regeneration of damaged dentin. Therefore, in this study the effects of mentioned biomaterials on migration of hDPSCs and the secretion of some chemoattractive molecules by these cells were examined. MATERIALS AND METHODS: The cell viability of hDPSCs was assessed using MTT assay. Transwell migration assay was used to determine cell migration ability. The cytokine secretion was evaluated using enzyme-linked immunosorbent assay. RESULTS: The biomaterials of MTA, CEM, and Biodentine at different dilutions had no cytotoxic effects on hDPSCs at different time points; however, non-diluted extract of TheraCal showed toxic effects after 24, 48, and 72 hr. Meanwhile, the highest cell migration was observed in the presence of CEM and Biodentine (P<0.05). The secretion of MCP-1 and TGF-ß1 were higher in hDPSCs treated with Biodentine compared to some other groups (P<0.05, P<0.01). Moreover, TheraCal decreased protein secretion of TNF-α (P<0.05), and IL-8 (P<0.01) in hDPSCs. CONCLUSION: The biological compatibility associated with CEM and Biodentine indicates promising applications in the field of vital pulp therapy.

Evaluation of Dentin Adaptability of Fluoride Varnish as a Root Canal Sealer Using Scanning Electron Microscopy.

OBJECTIVES: This study aimed to assess the dentin adaptability of a certain type of fluoride varnish, as a novel root canal sealer, in comparison with AH-Plus sealer. MATERIALS AND METHODS: Twenty-four extracted single-rooted, single-canal human permanent teeth with straight and fully formed roots and no internal calcification, resorption or cracks, were selected and decoronated such that the remaining root length was 14 mm in all teeth. Root canals were prepared using the Mtwo rotary file system according to the manufacturer's instructions and filled with gutta-percha and either AH-Plus (n=12) or fluoride varnish (n=12) via the lateral compaction technique. Each root was then sectioned at 4 and 8 mm distances from the apex for evaluation under a scanning electron microscope (SEM). The gap size between the sealer and dentin was measured. Statistical analysis was performed using the Kolmogorov-Smirnov test and t-test with the significance level set at 0.05. RESULTS: The mean gap size was 14.407±1.402 µm and 8.342±0.694 µm in the roots obturated with AH-Plus and fluoride varnish sealers, respectively. The t-test revealed a statistically significant difference (P<0.001) in this regard between the two groups. CONCLUSION: Fluoride varnish, as a root canal sealer, has a superior adaptation to dentinal canal walls compared to the AH-Plus sealer.

Effects of Two Calcium Silicate Cements on Transforming Growth Factor-ß1 Secretion from Human Dental Pulp Stem Cells.

Introduction: The aims of this in vitro study were to evaluate the effects of two calcium silicate based cements, Calcum-enriched Mixture (CEM) and Biodentine on proliferation of human dental pulp stem cells (hDPSCs) and the effects of proposed cements on the secretion of Transforming Growth Factor ß1 (TGF-ß1). Methods and materials: The cell cultures of human Dental Pulp Stem Cells (hDPSCs) at passage 3-5 were treated with various dilutions (1/1, 1/2, 1/4, 1/8, 1/16, and 1/32) of CEM and Biodentine extracts to assess the cell proliferation using 3-(4, 5-dimethylthiazol-2-Y1)-2, 5-diphenyltetrazolium brovide (MTT) assay after 48 and 72 h. The amount of TGF-ß 1 secretion were estimated after 72 h using an enzyme-linked immunosorbent assay. Data were analyzed using the one-way analysis of variance (ANOVA) followed by the Dunnett's test at the level of significance set at 0.05. Result: CEM showed the highest rates of cell proliferation compared to Biodentine after 72 h (P<0.05). A greater amount of TGF-ß1 was secreted by hDPSCs treated with Biodentine compared to CEM (P<0.05). These differences were statistically significant (P<0.05). Conclusion: In this in vitro study hDPSCs showed more proliferation capacity with CEM rather than Biodentine and TGF-ß1 secretion rate in Biodentine was higher.

Subcutaneous Connective Tissue Reaction to a New Nano Zinc-Oxide Eugenol Sealer in Rat Model.

INTRODUCTION: The aim of this animal study was to evaluate the histological response of the new nano zinc-oxide eugenol (NZOE) sealer in comparison with Pulp Canal Sealer (ZOE based) and AH-26 (epoxy resin sealer). METHODS AND MATERIALS: A total of 27 Wistar rats were used. Four polyethylene tubes were implanted in the back of each rat (three tubes containing the test materials and an empty tube as a control). Then, 9 animals were sacrificed at each interval of 15, 30 and 60 days, and the implants were removed with the surrounding tissues.Samples were evaluated for the presence of inflammatory cell (mononuclear cell), vascular changes, fibrous tissue formation and present of giant cell. Comparisons between groups and time-periods were performed using the Kruskal-Wallis and Mann-Whitney U non-parametric tests. The level of significance was set at 0.05. RESULTS: No significant difference was observed in tissue reactions and biocompatibility pattern of three sealers during 3 experimental periods (P<0.05). In all groups the tissue behavior showed tendency to decrease the irritation effect over time. Conclusion: The new nano zinc-oxide eugenol sealer has histocompatibility properties comparable to conventional commercial sealers.

Cytotoxicity of a New Nano Zinc-Oxide Eugenol Sealer on Murine Fibroblasts.

INTRODUCTION: The aim of this study was to evaluate the cytotoxicity of a new nano zinc-oxide eugenol (NZOE) sealer in comparison with AH-26 and Pulpdent root canal sealers. METHODS AND MATERIALS: The L929 mouse fibroblast cells were cultivated and incubated for 24, 48 or 72 h with different dilutions (1/1, 1/2, 1/4, 1/8, 1/16 and 1/32) of culture media previously exposed to either of the test sealers naming NZOE, AH-26 or Pulpdent. At the end of incubation period, the effect of sealers on cell viability was evaluated using Mosmann's Tetrazolium Toxicity (MTT) colorimetric assay. The data was compared using the one-way analysis of variance (ANOVA) followed by the Tukey's post hoc test for multiple comparisons. RESULTS: After 24, 48 or 72 h, both NZOE and Pulpdent sealers inhibited cell viability at 1/1, 1/2 and 1/8 dilutions. Within the 24 and 48 h, the AH-26 sealer reduced the cell viability at all dilutions except the 1/32 solution; however after 72 h even the 1/32 dilution was cytotoxic. CONCLUSION: The biocompatibility of the nano zinc-oxide eugenol sealer was comparable to Pulpdent sealer and lower than AH-26.