Thesis (M.Sc.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Prosthodontics

Statement of problem; Ceramics are the most esthetic appealing material used in fixed prosthodontics. Oral media pH is unstable due to consumption of different beverages; these beverages can be acidic, by which they may adversely affect the material of the prosthesis either by staining it or by affecting its surface roughness depending on the material it was made of. Aim of study; The aim of this study was to assess color stability and surface roughness change of Lithium disilicate and Hybrid ceramics after immersion in staining acidic solutions with different pH values (carbonated orange and coffee beverages). Materials and methods; 26 plates of each material were sectioned using Isomet 4000, Then the samples were randomly divided into 2 subgroups (n=13), After plates preparation baseline readings of color parameters were done using spectrophotometer, for the roughness using stylus profilometer, surface topography was assessed by scanning with Scanning Electron Microscope (SEM). Then each subgroup of material was immersed in an acidic beverage (Coffee and Miranda orange) for 168 hours/7 days then retested for the previously mentioned parameters. Differences between pre and post immersion readings of color parameters and surface roughness for the tested groups and subgroups were calculated, tabulated and statistically analyzed more susceptible to color and roughness change than E.max CAD

Issued also as CD