Probiotics for future caries control: a short-term clinical study.

OBJECTIVES: To compare mutans streptococci levels in saliva, before and after consumption of probiotic ice-cream and curds. MATERIALS AND METHODS: Forty caries free children in the age group of 12-14 years were selected and equally divided into four groups I, II, III, IV. Children in group I and II were given 100 ml probiotic ice-cream and plain ice cream respectively and group III and IV were given 100 ml probiotic curd and plain curd respectively for a period of 7 days. Saliva samples were assessed at baseline, 1 hour after consumption and after 7 days intervention period using Mitis salivarius Bacitracin agar. The number of colonies was counted and subjected to statistical analysis. RESULTS: The study revealed a reduction in salivary mutans streptococci (MS) counts after 1 hour in all the groups. However after 7 days, probiotic ice-cream and curd showed a statistically significant (P < 0.001) reduction in MS counts as compared to the control ice cream and curd. The difference in the reduction of MS counts with probiotic ice-cream and probiotic curd at 1 hour and 7 days was not statistically significant. CONCLUSION: The use of probiotic products could be an alternative strategy of displacing pathogenic microorganisms by probiotic bacteria and can thus be exploited for the prevention of enamel demineralization.

Effect of chemical disinfectant on the transverse strength of heat-polymerized acrylic resins subjected to mechanical and chemical polishing: an in vitro study.

AIMS: To evaluate the effect of chemical disinfectant on the transverse strength of heat-polymerized acrylic resins subjected to mechanical and chemical polishing. MATERIALS AND METHODS: A total of 256 rectangular specimens (65 * 10 * 3 mm) 128 per resin (Lucitone-199 and Acralyn-H) were fabricated. One side of each specimen was not polished and the other was either mechanically (n = 96) or chemically (n = 96) polished and immersed for 10, 30 and 60 minutes in 2% alkaline glutaraldehyde. Mechanically polished (n = 32) and chemically polished (n = 32) control specimens were immersed only in distilled water. The transverse strength (N/mm(2)) was tested for failure in a universal testing machine, at a crosshead speed of 5 mm/min. Data were statistically analyzed using 2-way ANOVA and Student t-test. RESULTS: chemical polishing resulted in significantly lower transverse strength values than mechanical polishing. Lucitone- 199 resin demonstrated the highest overall transverse strength for the materials tested. Heat-polymerized acrylic resins either mechanically or chemically polished, did not demonstrate significant changes in transverse strength during immersion in the disinfecting solution tested, regardless of time of immersion. CONCLUSION: Lucitone-199 resin demonstrated the highest overall transverse strength for the materials tested and significantly stronger than Acralyn-H with either type of polishing following immersion in 2% alkaline glutaraldehyde. CLINICAL SIGNIFICANCE: There is a concern that immersion in chemical solutions often used for cleansing and disinfection of prostheses may undermine the strength and structure of denture base resins. In this study it was observed that, the transverse strength of samples of Lucitone-199 was higher than that of the samples of Acralyn-H. The chances of fracture of the denture made of Lucitone-199 are less than that of dentures made of Acralyn-H. The chemically polished dentures may be more prone to fracture than mechanically polished dentures.