Application of a Novel Bio-mimic System to Analyze Denture Biofilms

Objectives: Clinical observations estimated that ~60% of dentures-wearing patients experienced some forms of microbial induced stomatitis, which may further progress to severe oral or systemic infections. Little research has been conducted in this area and few products are available to control the problem. We, a collaborative research team between GSK and UCLA, aim to address this problem. Methods: A high-throughput in vitro biofilm model system was developed that allows us to grow various microbial biofilms on surfaces made of real denture materials or hydroxyapatite materials. Using the single species biofilms of key oral pathogens Candida albicans and Streptococcus mutans, as well as saliva-derived biofilms that mimics dental plaques, we analyzed how microbes may colonize differently on these surfaces. We have utilized this study system to assess the efficacy of denture cleansers against various biofilms. Results: S. mutans exhibited similar affinity in binding to both denture and hydroxyapatite materials, while salivary bacteria adhere to hydroxyapatite material with higher affinity than denture materials. Interestingly, C. albicans showed increased colonization onto denture materials. Using this newly established study system, we also found that denture cleansers were able to kill at least 90% of the biofilm cells in a short 5 minutes exposure period. Conclusion: The fact that many results described above are consistent with previous clinical observations validates the usefulness of this new biofilm study system. Furthermore, the study validates the efficacy of GSK Polident® denture cleansers against various oral pathogens and biofilms in a short 5 minutes exposure period. The study was supported by a grant from GSK.