Effect of 10% cerium chloride on artificial caries lesions of human enamel evaluated using quantitative light-induced fluorescence: an in vitro study.

AIM: To evaluate the effect of 10% cerium chloride intervention on pre-demineralised human enamel subjected to cycles of de- and remineralisation. METHODS: This was an in vitro, comparative type study of 60 human enamel samples that were randomly divided into control and test groups. The samples were then subjected to a cycle of demineralisation followed by intervention with respective treatment solutions (control group: placebo solution; test: 10% cerium chloride) for 30 s under constant agitation and then to a 2nd cycle of demineralisation followed by remineralisation using artificial saliva. After the first and second cycles of demineralisation (4th and 8th day) and a cycle of remineralisation (22nd day), the samples were evaluated for fluorescence values using a quantitative light-induced fluorescence camera. The data was analysed using paired t test and ANOVA. RESULTS: Comparing the fluorescence values and mean difference of lesion area between the first cycle of demineralisation to the cycle of remineralisation and the second cycle of demineralisation to the cycle of remineralisation, the test group showed a statistically significant reduction in loss of fluorescence values and lesion area compared to the control group (p < 0.001). Mean fluorescence values and lesion area comparison between cycles of de- and remineralisation for control and test groups (inter-group comparison) showed a statistically significant difference (p < 0.001). CONCLUSIONS: Cerium chloride alone reduced demineralisation and improved remineralisation of artificial caries lesions in human enamel when subjected to pH cycling in vitro.

Effect of dentifrice of varying fluoride concentration on surface microhardness of fluorosed enamel: an in vitro study.

AIM: To evaluate the effect of dentifrice with varying concentrations of fluoride on surface microhardness of fluorosed enamel as compared to a non-fluoridated dentifrice. STUDY DESIGN: In vitro, comparative type. METHOD: 60 enamel blocks with score-3 enamel fluorosis were randomly divided into three groups: Group I non-fluoridated dentifrice, Group II 1000-ppm fluoridated dentifrice and Group III 1400-ppm fluoridated dentifrice. After evaluating the baseline surface microhardness, samples from each group were brushed for 2 min, twice daily for a period of 21 days with 0.02 g of respective interventional agents as per protocol. Microhardness of the samples was re-evaluated at the end of 21 days. Statistical analysis was performed using paired t test, ANOVA and Kruskal-Wallis test. RESULTS: The surface microhardness within the group from the baseline to 21st day post intervention, showed a statistically significant increase in all three groups, hence indicating that all the three interventional agents used were effective against the fluorosed enamel surface. Intergroup comparison of the surface microhardness of fluorosed enamel from baseline to 21st day post intervention showed a statistically significant difference (p < 0.001) amongst the groups with Group III proving most effective followed by Group I and Group II. CONCLUSION: 1400-ppm fluoridated dentifrice is more effective as compared to 1000-ppm fluoridated dentifrice and non-fluoridated dentifrice in increasing the surface microhardness of fluorosed enamel.

Clinical evaluation of sustained-release metronidazole gel versus metronidazole solution as an intracanal medicament in abscessed primary molars.

AIM: To evaluate the efficacy of metronidazole gel versus metronidazole solution against Enterococcus faecalis in abscessed primary molars. STUDY DESIGN: A clinical trial. METHOD: Twenty pulpally involved non-vital carious human primary mandibular second molars with furcal abscess were randomly allocated into two groups to evaluate the efficacy of metronidazole gel (3% w/v) and metronidazole solution (0.5% w/v) against E. faecalis. Subjects in the first experimental group were subjected to treatment with metronidazole gel (3% w/v) and subjects in the second experimental group were treated with metronidazole solution (0.5% w/v). Two microbial samples (pre-operative and post-operative samples) were obtained from the root canals of each subject from both the groups; sub cultured and efficacy of both the groups were evaluated. RESULTS: Overall percentage reduction of the mean colony forming unit (CFU) count of metronidazole gel (3% w/v) group was 96.39% and metronidazole solution (0.5 % w/v) was 90.90%. Results of intergroup t test of the percentage difference of mean CFU counts between both the groups revealed a statistically highly significant difference, i.e. p value--0.008 (p < 0.01). CONCLUSIONS: Metronidazole gel (3% w/v) was more effective than metronidazole solution (0.5% w/v) against E. faecalis.