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Increasing demands for aesthetically pleasing dental restorations have promoted the use of materials that display superior optical properties. Zirconia-based all-ceramic systems have good optical properties, thus providing the desired esthetics for dental restorations. The altered oral conditions impact the physical properties of these materials. Multiple studies have been conducted to evaluate the effect of aging on the mechanical properties of computerized-aided design and computerized-aided manufacturing (CAD/CAM)-based zirconia; however, there is a scarcity of literature discussing the effect of aging on change in translucency, contrast ratio, and color. Therefore, this research aimed to evaluate the effect of accelerated artificial aging on translucency parameter (TP), contrast ratio (CR), and color of CAD/CAM zirconia at different sintering temperatures. Twenty-eight rectangular-shaped specimens were obtained by CAD/CAM milling of zirconia blank. Sintering of the samples was carried out at four different temperatures 1350 °C, 1400 °C, 1450 °C, and 1500 °C, respectively. Thermocycling of the samples was performed in a thermocycler. TP, CR, and color evaluation of all the samples was done again using a Spectrophotometer. Data acquired were statistically evaluated by one-way ANOVA and Post Hoc test. The highest amount of change in TP was recorded for specimens sintered at 1400 °C (1.86), whereas the least change was attributed to 1350 °C (0.51). The highest change in CR was observed in specimens sintered at 1500 °C (0.0971), and the least change in CR was observed at 1450 °C (0.0086). The highest ΔE values were recorded for 1400 °C against both white (1.86) and black background (2.17), whereas the least change was attributed to 1350 °C against white (0.86) and against a black background (1.41). The changes in TP were significant, but CR did not show any significant change. ΔE values for all the experimental groups were significant, but were below the clinically perceptible range. An increase in sintering temperature increased the translucency.

The aim of this systematic review was to evaluate the marginal fit and internal adaptation of provisional crowns and fixed dental prostheses (FDPs) fabricated using 3D-printing resins and compared them with those fabricated by CAD/CAM (computer-aided designing/computer-aided manufacturing) milling and conventional resins. The null hypotheses tested were that there would be no differences in the marginal fit and internal adaptation of 3D-printed provisional crowns and FDP resins when compared to CAD/CAM-milled and conventional provisional resins. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to construct this systematic review. The focused PICO/PECO (Population, Intervention/Exposure, Comparison, Outcome) question was “Do provisional crowns and FDPs (P) fabricated by 3D-printing (I) have similar marginal adaptation and internal fit (O) when compared to those fabricated by CAD/CAM milling and conventional techniques (C)?”. The protocol used for this systematic review was pre-registered in the International Prospective Register of Systematic Reviews (PROSPERO). Electronic databases (e.g., MEDLINE/PubMed and Web of Science (Core Collection)) were systematically searched for indexed English literature published up to June 2022. In the initial electronic search of the selected databases, 519 articles were identified. Duplicates were removed, and screening was performed to select the articles that met the preset inclusion criteria. Sixteen studies were selected for qualitative analysis, but only ten of them provided comparative data and were selected for quantitative analysis. The modified CONSORT scale was used for qualitative analysis, and most of the included studies were rated to be of moderate quality. Based on the findings, it could be concluded that provisional crowns and FDPs fabricated from 3D-printing resins have a superior marginal fit and internal adaptation when compared to CAD/CAM-milled and conventional provisional resins; thus, they can be used as a dependable alternative to other resins.