Evaluation of fracture resistance and color change of monolithic restorations with different thicknesses

In this thesis, the fracture resistance and color change of monolithic restorations produced from different materials and with varying thicknesses, in which thermal cycles were applied, were examined. Anatomically prepared acrylic tooth (number 26, Fraseco) was reproduced CAD/CAM. The occlusal thicknesses of the crowns are produced in two different designs as 1 mm and 1.5 mm. Axial walls, on the other hand, are designed as 1 mm, due to the evaluation of the color change at the same thickness. In order to evaluate the change of the cemented crowns, color measurement was performed with a spectrophotometer before and after the thermal cycle. The fracture resistance of the non-thermal cycled samples and the thermal cycled samples were measured and recorded as N. As a result of the study, the color change in all materials was found below the acceptable threshold value. The difference between GC Cerasmart (C) and Vita YZ XT (XT) and Vita YZ T (T) was found to be statistically significant. The difference between (C) and Vita Suprinity (S) is not significant. ΔE00 values of the materials; It was found to be 1.56 (C), 0.95 (XT), 1 (T) and 1.19 (S). When the fracture resistance was evaluated as a result of thermal cycling, the difference was found to be statistically significant only in the sample of (T) material prepared in 1 mm occlusal thickness. With the increase in material thickness, the fracture resistance was found to be statistically significant in all groups except (C). The fracture resistance of 1 mm and 1.5 mm thick (S) material was lower than all other materials and statistically significant. As a result of the study, all materials color change were found acceptable and were found suitable for use. The material (S) with 1 mm occlusal thickness has not been found suitable in posterior restorations.