Effect of different polishing methods on streptococcus mutans adhesion of CAD/CAM materials

CEREC Blocs with feldspathic porcelain, IPS e.max CAD with lithium disilicate glass-ceramic, IPS Empress CAD with leucite-reinforced glass- ceramic and CAD/CAM blocks of Vita Suprinity and zirconia reinforced lithium silicate glass ceramic content were used. Enamel sections were used as control group. Ceramic groups (n=20) and natural teeth (n=10) were prepared (5x5x1 mm). The ceramic materials were randomly divided into 2 subgroups (n=10). One group of each material was prepared for glase treatment, the other group was polished with hand tools. Surface roughness for all specimens was measured with a profilometer. The samples were coated with musin containing artificial saliva for 1 hour to form pellicle layer on the surface. After 24 hours of incubation with Streptococcus mutans strain, colonies were counted to determine the retention of microorganisms. SEM images were taken to examine the surface topography. With respect to surface roughness, glazed groups were significantly smoother than enamel section and manual polished groups (p<0.05). The highest mean surface roughness was obtained in the enamel sections. The lowest bacterial density was found in enamel in the groups compared for bacterial adhesion. Glazed CEREC Blocs and manual polished IPS e.max CAD showed the lowest bacterial adhesion after enamel group. Positive correlation without statistically significant between roughness and bacterial adhesion was found (p>0,05). It is concluded that glaze treatment is a more effective method for forming a smooth surface in restorations. The absence of a strong correlation between bacterial adhesion and surface roughness suggests that physicochemical properties are also effective in adhesion.