Effect of conditioning films on oral microbial biofilm development

The aim of the study was to evaluate the influence of either host‐ or microbially‐derived conditioning films on biofilm formation. Hydroxyapatite (HA) discs were pre‐treated either with parotid saliva (2h incubation), or with crude glucosyltransferase (GTF) preparations (3h incubation in culture supernatant of Streptococcus sanguis or Streptococcus mutans, with sucrose), and then immersed in a mixed culture of oral bacteria grown in continuous culture. Discs were removed from the culture after 4d, and biofilms were detached with a sterile probe. Numbers of bacteria in the biofilms on pre‐treated discs were determined by differential viable counts, and results were compared with untreated discs. Pre‐treatment with GTF from S. sanguis or S. mutans increased the total CFU on discs immersed in the culture for 4 d by 29% and 95% respectively, although these differences were not statistically significant. The two GTF preparations had differential effects, with the S. sanguis preparation increasing the numbers o...