Effect Of Probiotics On Plaque Biofilm In Vitro

[Objective] Dental caries is a bacterial disease resulted from the imbalance of oral commensal microorganisms. Bacteriotherapy has been regarded as a promising method to prevent dental caries. The aim of this study was to evaluate the effects of intestinal probiotic products on dental plaque biofilm in vitro and to explore their potential value for caries prevention, so as to recommend effective anti-caries probiotic products for clinical comprehensive prevention and treatment of dental caries.[Methods] Questionnaires for parents and pediatricians were designed and conducted by the purposive sampling method, so as to investigate the usage of probiotics products.The dental plaque biofilm was established in an artificial mouth model in vitro and was treated with two probiotic products respectively by simulating intestinal medicine taking method. Scanning Electron Microscopy was used to observe the formation procedure and the surface morphology of plaque biofilm. Real-time Quantitative PCR was used to observe the growth of bacteria in plaque biofilm.[Results] (1) Results of questionnaire:Probiotic granules (79.2%), Two live bacteria tablets (43.6%), Triple viable tablets (33.7%), Triple viable graupel (5%) were the probiotic products which parents trusted and Probiotic granules was the most trusted one (P<0.05). Pediatricians often recommend Triple viable tablets (71.8%), Two live bacteria tablets (69.1%), Probiotic granules (40.9%), Triple viable graupel (20.0%) for children and Triple viable tablets was the most recommended one (P<0.05). (2) Effects of probiotics on the surface morphology of plaque biofilm: ①In control group:At 6h, a small amount of bacilli and cocci adhered to the HA surface; From 24h to 72h, the main bacteria on the surface of HA were gradually transformed from bacilli to streptococcus and actinomyces, and bacteria were observed to aggregate together; From 48h to72h, the main bacteria on the surface of HA were bacilli and streptococcus, which formed a biofilm structure. ②In experimental group:During the continuous culture of 6h,24h,48h,72h, compared with the control group, the bacteria’s amount on the surface of HA in experimental groups’were less. The mainly bacteria on the surface of HA were bacilli and a small amount of cocci. Most bacteria were observed to distribute widely and seldom aggregated together or formed biofilm structure. (3) Effects of probiotics on the growth of bacteria in plaque biofilm:① During the continuous culture of 6h,24h,48h,72h, compared with the control group, both Probiotic granules and Triple viable graupel could effectively inhibit the growth of S. mutans in dental plaque biofilms (P<0.05), but there was no significant difference between the two groups (P>0.05);②In Probiotic granules group, the amount of L. acidophilus in plaque biofilm was increased (P<0.05).[Conclusion] Probiotic granules and Triple viable graupel could effectively inhibit the formation of the dental plaque biofilm, and inhibit the growth of S. mutans in dental plaque biofilms. Therefore, they are worth further study on their value of prevention and treatment of dental caries in vivo, so as to we can recommend effective anti-caries probiotic products for clinical comprehensive prevention and treatment of dental caries.