Inhibition of early biofilm formation by glass-ionomer incorporated with chlorhexidine in vivo: a pilot study

Background: This pilot study investigated the antibiofilm effects of glass-ionomer cements (GICs) and resin-modified glass-ionomer cements (RMGICs) incorporated with chlorhexidine (CHX) in vivo. Methods: Experimental GICs and RMGICs containing 2% CHX were obtained by mixing CHX with the powder of GICs (CHXGIC) and RMGICs (CHXRMGIC). Four groups of specimens were prepared in a standardized size. After polishing and sterilization, they were bonded to the buccal surface of the molars in the first and second quadrant of volunteers and left untouched for 4 hours and 24 hours, respectively. The bacterial vitality of plaque was then analysed by confocal laser scanning microscopy (CLSM). The bacterial morphology and biofilm accumulation were determined by scanning electron microscopy (SEM). The pH value of biofilm was assessed by Plaque Indicator Kits. Results: CLSM analysis revealed that bacterial vitality of the biofilm on CHXGIC and CHXRMGIC was significantly lower than that on GIC and RMGIC. SEM analysis indicated that the morphology of bacteria on CHXGIC and CHXRMGIC was irregular. The pH value of biofilm on the experimental materials presented no statistically significant difference. Conclusions: Twenty-four hour bacterial vitality on GICs and RMGICs with CHX are lower in micro-organisms than on conventional GICs and RMGICs.