The Effect of Toothpaste Suspensions on the Formation of Oral Biofilms In Situ.

OBJECTIVES: Toothpastes are essential for oral hygiene and plaque control, yet limited data exist on their ability to inhibit biofilm formation. This study evaluated the biofilm-inhibiting effects of four toothpastes using an in situ biofilm model. DESIGN: Paste I contained fluoride, chlorhexidine, and aluminum lactate. Paste II added strontium acetate and potassium chloride to Paste I. Paste III included hydroxyapatite, and Paste IV contained papain and bromelain. Controls included water, a base paste, and 0.2% chlorhexidine. Six volunteers wore acrylic splints with bovine enamel slabs and rinsed with toothpaste suspensions at intervals over 48 hours. Biofilm coverage and bacterial viability were assessed via fluorescence microscopy using live/dead staining. RESULTS: Results showed reduced biofilm coverage with Paste I (31%*), Paste II (29%*), Paste IV (30%*), and Paste III (40%) compared to water (72%) and base paste (47%). Chlorhexidine showed the lowest coverage (10%). Viability of bacteria (green fluorescence) was lowest with Paste III (9%*), followed by Paste I (31%*), Paste II (28%*), and Paste IV and chlorhexidine (each 39%). Water and base paste showed higher viability (54% and 51%, respectively). Statistically significant differences were found compared to water (Mann-Whitney U-test, *P < .05). CONCLUSIONS: Toothpastes with active ingredients significantly reduced biofilm formation and/or viability. Paste III, containing hydroxyapatite, was particularly effective in reducing bacterial viability. Further research is needed to explore alternatives to chlorhexidine as a preservative.