An In Vitro Model for Evaluating Oral Health Care Products

Abstract

Aim or Purpose: Streptococcus mutans biofilms are a well-known cause of tooth decay. To prevent caries and periodontal diseases, precise plaque control using antibacterial products is necessary. The aim of this study was to establish an in vitro oral biofilm model that is more reliable than planktonic bacteria for evaluating the antibacterial properties of oral health care products. Materials and Methods: Acrylic discs, used as a substrate for biofilm formation, were fabricated from self-cure acrylic resin and sterilized. The discs were then incubated with filtered saliva to promote acquired pellicle formation. Then, saliva was removed, and a mixture of saliva, brain heart infusion (BHI) broth supplemented with sucrose, and Streptococcus mutans suspension were added to one group of discs. Negative controls did not receive bacterial suspension. After 48 hours of incubation, the discs were rinsed with saline to remove loosely adherent bacteria, vortexed in saline, and serially diluted for bacterial enumeration. One disc of each group was used for scanning electron microscopy (SEM). Results: The mean number of counted colonies in the positive control group was 5.13 × 105, while no colonies were detected in the negative control group. SEM micrographs showed biofilm accumulation on the surface of the positive control disks, while no bacteria were observed on the surfaces of negative control samples. Conclusions: We have developed an in vitro model of dental plaque using saliva and S. mutans. This model can serve as a valuable tool for evaluating the antibacterial efficacy of oral health care products, such as fluoride varnishes, mouthwashes, and toothpastes, designed to prevent biofilm formation on dental surfaces and dental caries.