[Plaque accumulation (S. mutans) in various dental restorative materials and fluoro-resins (in vitro)]

The quantities of in vitro accumulated plaque (S. mutans), cultured in 5% sucrose BHI broth, to the surface of PMMA, Co-Cr alloy, porcelain, PTFE, PCTFE, Composite PCTFE, and detachment time as an indicator of plaque retaining capacity, were measured. The former increased with the increase in surface roughness on all materials, except for the Co-Cr alloy, and with contact angles, which suggests that hydrophobic interaction may play an important role for formation of plaque on materials. By contrast, the quantities of accumulated plaque, cultured in 5% sucrose BHI broth containing synthetic saliva constituents, to the surface of various materials, also increased with the increase in surface roughness, but decreased with values of contact angles, which suggest that the effect of hydrophobic interaction on forming plaque to materials seems to be weakened by constituents of synthetic saliva.