Influence of surface roughness on Streptococcus mutans adhesion forces to denture base resins

• 1、State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041

Abstract：Objective: To measure Streptococcus mutans adhesion forces with denture base resins with different surface roughness using atomic force microscope (AFM), discussing the influence of surface roughness on bacterial adhesion force. Methods: Polishing and grinding were applied to obtain denture base resins disc samples by 400，800，1500 and 2500 sandpapers, surface topography was measured by AFM. Adopting Streptococcus mutans to obtain bacteria-modified AFM probes, adhesion forces of bacteria on the surfaces of denture base resins were measured using AFM in adhesion buffer, three positions were selected on randomly and every position being repeated 50 times, adhesion forces were acquired from force-distance curves. Material surface roughness was analyzed using ANOVA, and adhesion forces analysis was carried out by Weibull(P<0.05), correlation analysis was applied to material surface roughness and bacterial adhesion forces. Results: with the polishing of denture base resins, the surface roughness significantly reduced（306.14nm-13.36nm）accordingly and bacterial adhesion forces increased with increasing roughness of the material（1.46nN-3.78nN）, adhesion forces of Streptococcus mutans achieved maximum on the material surface of 200nm, there is a significant linear correlation between bacterial adhesion forces and material surface roughness. Conclusion: there is a significant positive correlation between roughness of the denture base resins and bacterial adhesion forces.

Keywords： denture base resins atomic force microscope adhesion force roughness streptococcus mutans