Susceptibility of S. sanguis biofilms to glass-ionomer cement substratum

Objective: The aim of this study was to use a biofilm-based model (Constant Depth Film Fermenter) to investigate the effect of glass-ionomer substratum on S. sanguis biofilms over the period of 5 days. Methods: Discs of experimental water activated conventional glass-ionomer cement (Advanced Healthcare Ltd, UK) were prepared according to the manufacturer’s instruction. Hydroxyapatite discs (HA) were used as controls. A 3-D laser scanning technique (Proscan 1000, UK) was used to characterise surface roughness and area of the substrate prior growing the biofilms. The CDFF system was used to grow S. sanguis biofilms on the substrates as described previously by Wilson et al. (Biomaterials 16;721-5, 1995). Specimens were removed from the CDFF aseptically at 1 day, 3 days and 5 days after the first delivery of bacteria. Viable counts of bacteria in the accumulated biofilms on each surface were measured and converted to colony forming units per surface area. The results were compared using non-parametric statistics (Mann-Whitney). Results: The viable counts of S. sanguis per square millimeter on GIC were significantly lower than on HA at 1 day, 3 days and 5 days (p< 0.05). Conclusions: This investigation shows that the growth of S. sanguis biofilms was influenced by glass-ionomer cement substratum over the period of 5 days.