Methods: Salivary bacteria from high caries risk and caries-free patients were cultured in an artificial mouth for 8 days on root surfaces as healthy and cariogenic biofilms respectively. They were subjected to 0.12% chlorhexidine gluconate (CHX) treatment. Biofilms were sampled daily for culture, identification, and denaturing gradient gel electrophoresis (DGGE). The changes of mineral and collagenous matrix on root surface were studied with Fourier Transform Infra-Red Spectroscopy (FTIR) and immunological staining.
Results: No significant difference of biodiversity was observed in healthy and cariogenic biofilms with the use of CHX. FTIR and immunological staining showed CHX significantly reduced mineral loss and damage of collagenous matrix on root surface were by cariogenic biofilm.
Conclusion: CHX did not significantly alter the biodiversity of cariogenic biofilm and protected the root surface against cariogenic challenge.