Elimination of E. faecalis with NaOCl versus chlorhexidine gluconate from primary molar root canal systems: an ex vivo model study.

OBJECTIVES: This ex vivo human study aimed to evaluate the efficacy of NaOCl and chlorhexidine gluconate (CHG) irrigations in eliminating Enterococcus faecalis from the RCS of primary molars. MATERIALS AND METHODS: Disinfected extracted primary molars were inoculated with E. faecalis for 24 h. Then, the RCS samples were then irrigated with either 2.5% NaOCl, 0.2% and 2% CHG, or sham saline. The samples were collected immediately after irrigation; and 24 h later, the bacterial viability and counts were measured using blood agar and qRT-PCR, respectively. Histological sections were used to measure E. faecalis penetration and viability in dentin tubules using fluorescence microscopy. RESULTS: The recovery of viable E. faecalis after the irrigation of the primary molars showed more significant bactericidal effects of NaOCl and 0.2% and 2% CHG than of saline. Immediately after the irrigation, the NaOCl group showed the greatest reduction in E. faecalis; and 24 h later, all the groups had lower viable E. faecalis than the saline control. The bacterial penetration was also lowest in the NaOCl group, although there was no difference in bacterial viability in the tubules between the groups. CONCLUSION: In primary teeth, NaOCl and CHG showed similar degrees of bacterial elimination efficacy in terms of E.faecalis. CLINICAL RELEVANCE: Within the limitations of this study, NaOCl and CHG have the similar ability to perform endodontic irrigation of primary ex vivo teeth regarding the elimination of E.faecalis, but NaOCl penetrates dentin tubules better.

Histological and chemical analyses of mesiodens development and mineralization.

OBJECTIVE: This study aimed to compare the developmental timing and mineralization quality of mesiodentes, i.e., supernumerary teeth located mainly in the midline of the maxilla between the central incisors, with the developmental timing and mineralization quality of permanent and primary central incisors. DESIGN: Sixteen mesiodentes, nine permanent and seven primary central incisors were collected. The location of the neonatal line was determined using a light microscope at 10× or 20× enlargements. Chemical composition of the enamel at two locations was analyzed using energy dispersive X-ray spectrometer. RESULTS: Neonatal lines were observed in eight out of 16 mesiodentes, in all primary central incisors and in none of the permanent central incisors. Chemical analyses showed that mesiodentes mineralization was impaired, resulting in higher amount of organic ions and reduced inorganic ions. Discriminant analysis showed minimal overlap of mesiodentes with either primary or permanent centrals. CONCLUSIONS: Mesiodentes development begins before birth in 50% of the cases but later than the primary centrals. Mineralization of mesiodens is impaired with less mineral content and higher organic content. The results showed that mesiodentes are a special group of teeth with defective morpho-differentiation and mineralization, with little similarity to primary or permanent central incisors.

Dentists' attitudes toward discussing Internet health information with their patients--does professional self-efficacy matter?

OBJECTIVE: The present study explored the relation between professional self-efficacy and the attitudes of dentists toward discussing Internet dental health information with their patients. METHODS: Fifty-seven dentists answered a questionnaire examining professional self-efficacy and attitudes toward patients wishing to discuss dental health information obtained through the Internet. RESULTS: A correlation was found between professional experience (in years) and professional self-efficacy [r point by serial (rpb) = 0.27, P < 0.05]. No statistically significant correlation was found between specialty and professional self-efficacy (rpb = 0.11, P < 0.4), and between professional self-efficacy and attitudes toward patients who wish to discuss dental health information (rpb = 0.22, P > 0.1). Specialists were more willing to converse with their patients than nonspecialists. Most participants did not find discussing information from the Internet to be time-consuming. CONCLUSIONS: This pilot study's results indicate that (a) Specialists in dentistry were more willing to discuss Internet dental health information with their patients than nonspecialists; (b) Dentists with high professional self-efficacy had a positive attitude toward patients who wish to discuss Internet dental health information with them; and (c) Further studies are needed to investigate and validate the results of the present study. PRACTICE IMPLICATIONS: High professional self-efficacy may improve general dentists' attitudes toward patients who wish to discuss Internet dental health information. The dental community should seek to expand the professional self-efficacy of its members in order to enable them to adequately deal with patients' needs.