The evaluation of the masking effectiveness of the crowns produced by different hybrid CAD/CAM blocks in the various thicknesses with rezin cement

The Evaluation of The Masking Effectiveness of The Crowns Produced By Different Hybrid CAD/CAM Blocks In The Various Thicknesses With Rezin Cement. University of Van Yuzuncu Yıl, Institute of Health Sciences, Prosthodontic Department, Phd Thesis, Van, 2019. Hybrid ceramics are frequently used because of their superior aesthetic properties and elastic properties close to the tooth texture. Hybrid ceramics it is a reflection of the color of the infrastructure in restoration in dentistry. There are several methods for masking this infrastructure. The aim of this thesis is to investigate the masking efficiency of the substructure, color of different hybrid ceramics in various thicknesses. In this trial, total of 120 test specimens were prepared for each group consisting of CAD/CAM blocks with 4 different contents (Cerec block, GC Cerasmart, Vita Enamic, 3M Lava Ultimate), 1 mm 1.5 mm and 2 mm. The samples were prepared by isomet knife with 100N pressure under distilled water. In the structure, A3 color Kuraray composite is used for substructure. G-CEM Link Force rezin cement was used for the cementation of the samples. After etching and bonding, the samples were cemented with rezin cement at 10N constant pressure. All samples were incubated at 37 °C for 24 hours in incubator after cementation. Samples from each group were measured by spectrophotometer (Spekctroshade Verona, Italy) 5 times. The L, a, b values of the samples were recorded in the excell program and the values were averaged. Changes in color were calculated with the formula ΔE. The values of the samples were recorded in SPSS program in ΔE and statistical analysis was performed. Kruskal Wallis test was used for statistical analysis and Dunn's test was used for group comparison. Significance was evaluated at least p <0.05. According to the findings of the study, it was found that the thickness made a statistically significant difference on the translucency. As the thickness of the ceramic increases, the substructure color is better masked. GC Cerasmart has the most effective masking efficiency among material. The lowest masking activity was observed in Cerec blocks. Key Words: CAD/CAM, Hybrid Ceramic, Masking