In Vitro Gap Changes After Porcelain Firing Cycles of Three and Four Unit of CAD/CAM Milling, Laser Sintering and Cast Metal Ceramic Restorations

Authors : Muhammed Abdullah KELES, Sebnem Begum TURKER

Pages : 271-277

Doi:10.33808/clinexphealthsci.565912

View : 21 | Download : 10

Publication Date : 2019-09-30

Article Type : Research Paper

Abstract :Objectives: Marginal adaptation changes during the veneering process is an important factor in the clinical success of metal framework techniques such as conventional cast metal cores insert ignore into journalissuearticles values(LW);, CAD-CAM Metal Milling insert ignore into journalissuearticles values(MM); and Direct Metal Laser Sintering insert ignore into journalissuearticles values(DMLS);. The aim of this study is to evaluate the marginal fit changes between three- and four- unit’s metal ceramic fixed partial dentures insert ignore into journalissuearticles values(FPD’s); fabricated by Lost Wax insert ignore into journalissuearticles values(LW);, CAM Metal Milling insert ignore into journalissuearticles values(MM); and insert ignore into journalissuearticles values(Direct Metal Laser Sintering); DMLS metal framework techniques after porcelain firing cycles insert ignore into journalissuearticles values(PFC);. Methods: A total of 60 stainless steel three and four unit FPD’s models were fabricated. Specimens were randomly divided into three groups to fabricate metal ceramic FPD’s frameworks with LW, MM and DMLS techniques. Before and after PFC, cross-sections from silicone replicas were obtained, sectioned, examined and measured with a light microscope. The statistical analysis was done with Mann-Whitney U and Kruskal Wallis and Wilcoxon Signed Ranks tests. Results were evaluated at 95 % of confidence interval and p<0.05 level. Results: There was a statistically significant difference between the three and four unit of FPD’s, before PFC for LW and MM insert ignore into journalissuearticles values(p:0.000); and DMLS insert ignore into journalissuearticles values(p:0.019);’s groups and only DMLS insert ignore into journalissuearticles values(p:0.006);’s group was statistically significant after PFC. The mean marginal gaps of LW technique was higher than the MM and DMLS’s techniques before PFC. After PFC, DMLS’s technique results were higher than LW and MM technique but, no statistically significant difference was found between the marginal gap values of the three and neither for four units of DMLS’s FPD’s. Conclusion: PFC decreases the mean marginal gap of the LW and MM group, but, there was a slight increase for DMLS group. However, all the marginal gap values obtained were in clinical acceptance level for three and four-units FPD’s for all tested specimens.
Keywords : Marginal gap, lost wax, CAD CAM, laser sintering, porcelain firing cycle