Mechanical Characteristics of Composite Resins Produced by Additive and Subtractive Manufacturing.

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.

Micro-Computed Tomography Analysis of Fit of Ceramic Inlays Produced with Different CAD Software Programs.

PURPOSE: The aim of this study was to evaluate marginal and internal fit of ceramic inlays designed with different computer-aided design software programs. MATERIALS AND METHODS: 11 typodont mandibular first molars were prepared as a ceramic class II mesioocclusal inlay cavity. Teeth were scanned using 3Shape TRIOS Intraoral Dental Scanner. The scan data, which was obtained in the form of a STL file, was designed in three different CAD systems (CEREC, KaVo, and Planmeca). The obtained STL scan data was exported to design inlay using three different CAD systems (CEREC, KaVo, and Planmeca). An independent 5-axis milling unit was used to manufacture the feldspatic inlay restorations. 11 measurements for each teeth were made by using micro-ct to evaluate the marginal and internal fit. One-way ANOVA was used to determine the statistical difference between groups, and Tukey posthoc test was used to determine intra-group differences. RESULTS: According to repeated ANOVA test results, a statistically significant difference was found between the groups for the variables A, D, and F. There was no statistically significant difference between the groups in linear measurements for other measurement points and volumetric measurements (p⟩0.05). CONCLUSION: Software programs of different systems affects the marginal and internal fit of inlay restorations.