IN VITRO COMP TRO COMPARISON OF CELL ARISON OF CELLULAR CYTOXICITY OF CONVENTIONAL VS. CAD/CAM DEN AL VS. CAD/CAM DENTURE BASE M TURE BASE MATERIALS

Abstract

Aim: Adverse reactions and local irritation of the oral mucosa to prostheses constructed from PMMA include allergic response, erythema, and a burning sensation of the tongue and mucosal tissues. Evidence on the cytotoxic effects of digitally manufactured denture base materials remains scarce. The aim of this study was to evaluate and compare the cytotoxic effects of CAD/CAM fabricated denture bases versus conventionally heat-cured acrylic resin materials. Materials and Methods: In total, 75 disks of five different denture resin materials – 15 disks per group were prepared: Ivocap (group 1; control), Ivotion denture base (group 2), Lucitone 3D denture base (group 3), Sprintray (group 4), and Flexera (group 5). Eluates of the materials from 1- and 7-days incubation in cell culture medium were used on human gingival fibroblasts seeded in 96-well microplates. Cytotoxicity was evaluated by MTT assay for both time points, and percentage cell viability was estimated. Effects on fibroblasts were also examined by Live/Dead fluorescence assay and phase contrast microscopy. MTT assay results were analyzed using analysis of variance (ANOVA) followed by Tukey’s post-hoc test. paired sample t-test was used for day-wise comparisons. Results are presented as mean±SD and p-values less than 0.05 were considered statistically significant. Results: MTT assay showed a lower cell viability for groups one and five when compared to the other groups. Statistically significant differences were detected between groups at day 1 [group 1 x 3 (p=0.0055), 1 x 4 (p=0.0025), 2 x 5 (p=0.0004), 3 x 5 (p<0.0001) and 4 x 5 (p<0.0001). No statistically significant differences between the groups were noted at day 7 MTT assay. Paired t-test indicated a decrease in cell viability at day 7 for groups 1 to 4 (p=0.0398; p=0.0075; p=0.0345; p<0.0001, respectively), indicating that exposure time affected viability. Microscopic analyses correlated with MTT findings and showed morphological changes for group 5 at day 1 incubation with extracts and group 1 at day 7 incubation. Conclusion: Cell viability levels were above the average threshold of ISO cytotoxicity potential standards, indicating the suitability of the studied denture base materials in clinical prosthodontics. However, all materials showed some degree of reduction of cellular viability.