Zobrazení zdroje stránky Corcoranbendtsen0309

To evaluate the minimal ceramic thickness needed to increase the lightness by one value by means of glass-ceramic restorations perceived by dental technicians, dentists, and laypersons.<br /><br /> A total of 15 assessment pairs (reference and test samples) were formed using glass-ceramic blocks in four different colors. Each assessment pair was comprised of two underground blocks differing in one value of lightness. On top of the underground blocks, glass-ceramic platelets were cemented in five different thicknesses (0.1 to 0.5 mm) and in the same color as the reference. Dental technicians, dentists, and laypersons (n = 41/group) were asked to determine the presence of a color difference between the two samples under standardized lighting conditions. The threshold ceramic thickness was defined as the thickness at which ≥ 50% of the evaluators were not able to perceive a difference within an assessment pair. The thresholds were analyzed, and groups were compared by applying chi-square test (P &lt; .05).<br /><br /> The majority of dentists and dental technicians (&gt; 50%) detected a lightness difference between the test and reference samples up to a ceramic thickness of 0.5 mm. The majority of laypersons (≥ 50%) did not perceive a lightness difference with ceramic thickness of 0.5 mm. If separated by the different color changes, the threshold ceramic thickness started at 0.4 mm and varied within the groups of evaluators and by the lightness of the assessed color.<br /><br /> A considerable number of evaluators perceived a lightness difference when minimally invasive ceramic restorations of 0.5-mm thickness were applied. [https://www.selleckchem.com/products/bms309403.html Selleckchem BMS309403] The threshold ceramic thickness, however, was reduced when the lightness of the substrate was lower.<br /><br />A considerable number of evaluators perceived a lightness difference when minimally invasive ceramic restorations of 0.5-mm thickness were applied. The threshold ceramic thickness, however, was reduced when the lightness of the substrate was lower.<br /><br /> To compare the accuracy of three commercially available intraoral scanners when imaging various dental material substrates.<br /><br /> A maxillary dentate typodont model with 11 different dental material substrates was prepared and scanned using three intraoral scanners (TRIOS 3, 3Shape; CS 3600, Carestream; and Emerald S, Planmeca). The model was further scanned with a laboratory scanner (7series, Dental Wings) for reference. Files were exported in standard tessellation language format and inserted into a metrology 3D mesh software (CloudCompare).<br /><br /> In terms of influence of different substrates on IOS trueness, a significant effect on the performance of TRIOS 3 and Emerald S was revealed. Concerning the accuracy of different intraoral scanners when scanning more translucent and reflective materials, pairwise comparisons revealed significant differences among scanners. In terms of complete-arch trueness and precision, pairwise comparisons revealed that TRIOS 3 had significantly higher trueness and precision comparedte group, TRIOS 3 exhibited significantly higher trueness compared to CS 3600. Polished and unpolished class II amalgam restorations of similar dimensions did not exhibit significant differences in trueness regardless of intraoral scanner. In terms of complete-arch accuracy, TRIOS 3 had significantly higher trueness and precision compared to CS 3600 and Emerald S. All three scanners exhibited complete-arch average accuracy below 100 μm.<br /><br /> To digitally evaluate the volumetric wear of four different implant-crown materials and their antagonists after artificial aging using an intraoral scanner (IOS) device and a laboratory desktop scanner.<br /><br /> A total of 48 implants were restored with monolithic crowns divided according to restorative material lithium disilicate (LDS), zirconia (ZR), polymerinfiltrated ceramic network (PICN), and porcelain fused to metal (PFM). Each specimen was scanned using a desktop scanner (LAB; iScan D104, IMETRIC 3D) and an IOS (TRIOS 3, 3Shape) before and after chewing simulation (1,200,000 cycles, 49 N, steatite antagonist, 5°C to 50°C). The obtained STL files were superimposed, and the volumetric loss of substance of the crowns and their antagonists was quantified (Materialise 3-matic). Kruskal-Wallis, Spearman rho, and paired t tests were used to analyze the data (α = .05).<br /><br /> The means of volume loss for each restorative material varied between 0.05 ± 0.06 mm<br /><br /> (ZR with IOS) and 3.42 ± 1.65 mm<br /><br /> (LDS with LAB). The wear of the antagonists was significantly lower (P &lt; .05) for ZR than the other groups. Increased wear of the crowns was highly correlated with increased wear of their antagonists (r<br /><br /> = 0.859). When comparing the wear measurement using the two scanning devices, no difference in mean volume loss was found (IOS 1.81 ± 1.81 mm<br /><br /> ; LAB 1.82 ± 1.78 mm<br /><br /> ) (P = .596).<br /><br /> Polished ZR was the most wear-resistant material and the least abrasive to the respective antagonist among the tested ceramics. For the quantification of wear, this IOS device can be used as an alternative to desktop scanners.<br /><br />Polished ZR was the most wear-resistant material and the least abrasive to the respective antagonist among the tested ceramics. For the quantification of wear, this IOS device can be used as an alternative to desktop scanners.<br /><br /> To compare patient-reported outcomes among balanced, lingualized, and monoplane occlusal schemes in relation to edentulous jaw classifications.<br /><br /> This randomized controlled trial was conducted in edentulous patients receiving new complete dentures using balanced, lingualized, or monoplane occlusal schemes. Demographic variables, bone ridge quantity, number of adjustments required after denture insertion, and satisfaction and quality of life (QoL) indices (ie, the Denture Satisfaction Questionnaire [DSQ] and General Oral Health Assessment Index [GOHAI], respectively) were assessed at 1, 2, 4, 8, 12, and 52 weeks. Within-group comparisons at different time points were carried out with Brunner-Langer nonparametric analysis. Furthermore, Kruskal-Wallis test was used to compare distributions of ordinal or continuous variables among the three occlusal scheme groups.<br /><br /> A total of 60 subjects (mean age 68.1 ± 11.1 years; 56.7% men and 43.3% women) were analyzed. All three groups presented significant improvements in DSQ and GOHAI scores between denture insertion and the 1-year follow-up appointment (P &lt; .