Fig. 5

Biofilm growth on hydroxyapatite surfaces pre-exposed to test rinses. Hydroxyapatite discs were soaked in mouthrinse formulations (final concentration, 100 %) containing CPC (TR) or CPC and fluoride (TFR). Control rinses without CPC (CR and CFR, respectively) and a treatment-free control (NTC) were also included. Six replicate discs for each treatment group were included. Biofilms were then cultivated on pre-exposed discs and mean total anaerobes were enumerated by viable counting. Surfaces exposed to both test rinses supported significantly less biofilm growth than their respective negative controls in six separate experiments (*, p < 0.05, n = 6). Pre-exposure to control rinses also resulted in less dense biofilms, although this effect was modest (^, p < 0.05, n = 6)