Evaluation of microbiological properties of computer-aided new generation denture base materials at different PH values

Objective: To evaluate the microbiological properties of conventional heatcured base material produced with new generation CAD/CAM at different pH values. Material and Method: For this study, a total of 108 polymethylmethacrylate samples with 2 x 10 mm dimensions were prepared. After measuring the surface roughness of the samples, they were artificially aged for 21 days in artificial saliva with 3 different pH values in the presence of 100% humidity at 37 degrees in order to mimic the oral environment. Roughness measurements were repeated at the end of the 21st day. The samples were disinfected with 70% alcohol and transferred to the brain heart broth medium containing candida albicans. At the 72nd hour of incubation, optical density of candida albicans was measured by spectrophotometer and biofilm forming abilities were determined. Compliance of the measurements with normal distribution, roughness values obtained at different pH levels in polymethylmethacrylate groups, Wilcoxon test, whether the roughness measurements obtained at different pH levels differed according to the groups and the comparison of C. albicans adhesion measurements according to the groups were examined using the Kruskal Wallis test. The relationship between roughness change and candida albicans adhesion at different pH levels was investigated by correlation analysis. Analyzes were performed with SPSS 20.0 software at 95% confidence level. Results: As a result of aging with artificial saliva with different pH values, surface roughness increased. The highest surface roughness was found in the samples kept at pH 3, and the highest surface roughness increase was found in the heat polymerized conventional PMMA samples. The highest C. albicans uptake was observed in heat-polymerized conventional PMMA samples. The relationship between increased surface roughness and C. albicans adhesion was not statistically significant. Conclusion: When the different types of PMMA base materials we used in our study were compared in terms of surface roughness, heat polymerized acrylic resin had a higher surface roughness value than other materials and the surface roughness of the materials increased more in acid environment. Among the denture base materials used in the study, C. albicans involvement was mostly found in heat polymerized acrylic resins. Keywords: CAD/CAM PMMA, C. albicans, digital CAD/CAM prostheses, graphene, PMMA, surface roughness