Purpose: The aim of this study was to evaluate the responses of human gingival fibroblast (HGF-1) in contact with provisional materials with various chemical compositions and fabricated using different methods.
Materials and methods: A total of 210 specimens in eight experimental groups were used. Groups were divided by chemical compositions (poly[ethyl methacrylate], poly[methyl methacrylate], bis-acryl, and hybrid ceramic) and fabricating methods (direct, indirect, and computer-aided design/computer-aided manufacturing [CAD/CAM]). To evaluate the surface characteristics of each group, roughness, water contact angle, and degree of conversion were measured. The responses of HGF-1 to provisional materials were evaluated with cytotoxicity and cell attachment assay. The roughness, surface energy, degree of conversion, level of cytotoxicity, and cell attachment were compared between groups using one-way analysis of variance (ANOVA) and Tukey's multiple comparison (α = .05).
Results: The poly(ethyl methacrylate)-direct/indirect and poly(methyl methacrylate)-direct/indirect groups showed higher roughness than the bis-acryl-direct/indirect, poly(methyl methacrylate)-CAD/CAM, and hybrid ceramic-CAD/CAM groups with statistical significance (P < .05). The poly(ethyl methacrylate)-direct group showed the significantly highest water contact angle, and the hybrid ceramic-CAD/CAM group showed the lowest water contact angle (P < .05). The groups that used indirect fabrication methods showed a higher degree of conversion than those that used direct fabrication methods, regardless of chemical composition (P < .05). The poly(ethyl methacrylate) groups showed significantly lower cell viability than the other groups regardless of fabricating methods (P < .05). The poly(ethyl methacrylate)-direct method group showed the lowest cell attachment, and the hybrid ceramic-CAD/CAM method group showed the highest cell attachment (P < .05).
Conclusion: Poly(methyl methacrylate) and bis-acryl have lower cytotoxicity to HGF-1 than poly(ethyl methacrylate). Indirect fabrication and CAD/CAM are recommended to prevent residual monomer and achieve high cell attachment. To use direct fabrication methods, the auto-mix system is beneficial for the favorable cell response, as it derives a smooth surface.