Surface features of CAD/CAM restorative materials and investigation of bacterial adhesion

Objective: The aim of this study is to investigate the surface properties of 4 resin-based CAD / CAM blocks and 1 leucite reinforced glass ceramic CAD / CAM block after standard polishing and finishing, and their interactions with S. Mutans and S. Mitis with the help of KLTM and SEM. Material and Method: IPS Empress CAD, VITA Enamic, Lava Ultimate, Shofu Blok HC and Cerasmart test materials were determined in the study. A total of 80 samples were prepared by taking 10 mm x 10 mm x 1 mm sections from the blocks with the help of a precision cutting device (n = 16). The samples were then randomly selected and divided into two subgroups (n = 5). After the polishing of the samples was carried out using Sof-Lex discs and polishing paste, the roughness values (Ra) were determined with the help of the profilometer. Sterile samples placed in Petri dishes were covered with artificial saliva and incubated for 1 hour at 37 ˚C oven for pellicle formation. Then, all samples were incubated for 24 hours in 5% glucose BHI medium containing S. mutans and S. mitis in 35 ˚C and 5% CO₂ medium. Bacterial colony count was determined with the aid of a microplate reader. Results: Statistical analysis was evaluated by applying Kruskal Wallis H test and post hoc Dunn-Bonferroni test. As a result of the roughness analysis, LAV and CER were statistically different compared to VIT and IPS (p <0.05) and no difference was found in the SHF group (p> 0.05). As a result of the hydrophobicity test, there was no statistically significant difference between the IPS group (p <0.05) and no significant difference between the other groups. The lowest hydrophobicity values were obtained for IPS and VIT. The lowest free surface energy (γtot [mN / m]) values were found to be in the CER group, followed by the SHF, LAV, VIT and IPS groups, respectively. No significant difference was found between the groups when comparing S. mutans and S. mitis bacterial colony (10⁸ CFU / ml) numbers (p> 0.05). Conclusion: Within the limitations of this in vitro study, no differences in biofilm formation were observed despite differences in surface properties. Pelikıl has been shown to play an active role in biofilm formation and to create adherent surface differences.