Cloning, Molecular ; methods ; Dental Caries ; immunology ; prevention & control ; Forecasting ; Humans ; Research ; trends ; Research Design ; Vaccination ; Vaccines ; genetics ; immunology

Objective:To compare the efficacy on root canal debridement of three ultrasonic units Odontoson-M, P-MAX and Spartan. Methods: Extracted healthy premolars with one single straight canal were used. The canals were prepared by step-down technique. After preparation, the canals were received ultrasonic irrigation and split longitudinally. Debris scores were calculated after photographing with a digital camera. The number of visible open dentinal tubules were evaluated by SEM. Results: At middle third of the canals, when irrigated with 5 g/L NaOCl, the debris score in group Odontoson-M was significantly lower than that in other groups(P

Dental Pulp Cavity ; anatomy & histology ; Humans ; Root Canal Preparation ; methods

Dental Pulp Cavity ; abnormalities ; pathology ; Humans ; Root Canal Therapy ; methods

China ; Humans ; Root Canal Therapy

Humans ; Periapical Periodontitis ; diagnosis ; etiology ; therapy ; Root Canal Therapy ; adverse effects

Humans ; Root Canal Obturation

Humans ; Root Canal Therapy ; instrumentation ; methods

Objective:To compare the antibiotic effects of 400 g/L chlorhexidine(CHX) varnish on different teeth surfaces. Methods: 400 g/L chlorhexidine(CHX) varnish was applied onto the left mandibula r first molar once in 5 young volunteers (group 1) or twice with a interval of I week in another 5 (group 2). The right mandibular first molar was served as th e control.Plaque samples from fissure or approximal surface were taken for Str eptococci mutans (S.mutans) detection with routine bacteriologic procedure onc e a week for 16 weeks. Results: In group 1 S.mutans in the plaque in fissue was significantly suppressed from 1 to 4 weeks after the v arnish application (P

Investigate the cleaning ability of manual ProTaper on mandibular second molars with C-shaped (c-shaped root) or normal root canal(separated root). Twenty mandibular second molars with C-shaped root or with separated roots were sectioned at 3.0, 5.5 and 8.0 mm from the root apex. The images of pre-preparation and F1, F2, and F3-prepapared of manual ProTaper were captured respectively. The cross-sectional areas of the canals were measured and the formula of area after treatment/area before treatment was used to calculate the area ratio. The data were analyzed by SPSS 10.0. The results showed that there was no statistically difference between cross-section root canal area ratios in two groups. Significant differences were found between the cross-section canal area ratio of F1 and F2, F1 and F3 at section 5 mm of S group, and F1 and F3 at section 3 mm of C group. The results suggested that the increasing of cross-section ratio of the two kinds of canals was not obviously concerned with their anatomical morphology.