ABSTRACT
Aim: The aim of this study was to evaluate the effectiveness of different finishing-polishing (FP) procedures on reducing surface roughness of nanoceramic hybrid CAD/CAM material before and after thermocycle (TMC) aging. Materials and Methods: Nano-ceramic hybrid CAD/CAM specimens were subjected to 8 different (2-glaze and 6-mechanical) FP procedures as follows (n=20): 1. Optiglaze (OG) 2. Diamond glaze (DG), 3. Vita Enamic Polishing Set (VE), 4. VE+Gradia Diapolisher paste (VE-G) 5. VE+Super-Snap SuperBuff (VE-S) 6. Sof-Lex Disc kit (SL) 7. SL+Gradia Diapolisher paste (SLG) 8. SL+Super-Snap SuperBuff (SL-S). Surface roughness of each specimen was measured by using a contact profilometer. All specimens were artificially aged with TMC (5000 cycles, 5°C/55°C) and surface roughness measurements were repeated. One extra specimen from each group before and after TMC was examined with SEM. Surface roughness data were analyzed by repeated measures ANOVA, dependent t-test and Tukey test. Results: Significantly higher mean Ra values were found for groups OG and DG compared to other groups (P<0.05). Differences between glaze groups and differences between mechanical FP groups were not significant (P>0.05). Groups SL-S and DG demonstrated comparable results before and after TMC (P>0.05). SEM analysis revealed that surfaces of VE-S and SL-S groups were smooth and free of scratches. Conclusions: Mechanical FP procedures were more effective in reducing surface roughness of nanoceramic hybrid CAD/CAM material than glaze applications. Sof-Lex kit followed by Super-Snap SuperBuff disc application can be recommended as the mechanical FP procedure of choice considering that this method provided smooth surfaces that were maintained after TMC.
Subject(s)
Ceramics , Computer-Aided Design , Humans , Aged , Materials Testing , Surface PropertiesABSTRACT
INTRODUCTION: The aim of the study was to evaluate the mechanical characteristics of resin composites produced by additive and subtractive manufacturing. METHODS: Six composite resin materials produced by subtractive (Vita Enamic-VE, Cerasmart-CE, Lava Ultimate-LU) and additive manufacturing (Varseo Smile Crown plus-VSC, Saremco Print Crowntec-SPC, Formlabs 3B Permanent crown-FLP) were selected. The three-point bending test was performed, and surface hardness of test specimens was measured. RESULTS: The flexural strength values of CE, SPC and LU test groups were found to be statistically higher when compared to VE, FLP and VSC test groups (p⟨0.0033). The modulus of elasticity values of the test specimens was listed as VE>LU>CE>SPC>FLP>VSC. The FLP group [35.11(4.46)] had the lowest surface hardness values, whereas the VE group [252.50 (21.5)] had the highest values. Other groups were listed as LU⟩CE⟩SPC⟩VSC in terms of surface hardness. CONCLUSIONS: According to the ISO 6872:2015, the flexural strengths of all resin composites were found to be acceptable for single unit fixed restorations. However, the VSC group's flexural strength is suitable for inlay, onlay, veneer restorations or single-unit anterior fixed dental prostheses. Also, VSC may not be a suitable choice for posterior restorations due to its low flexural strength.
