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

The aim of this present study was to investigate the effect of different finishing techniques (A: Glazing, B: Re-glazing, C: polishing) on the fracture resistance and surface roughness of In - Ceram crowns. A total of thirty coping core samples were constructed by using (CAD/CAM system) and divided into two equal groups(15 for each groups) group A: In ceram zirconia blocks and group B: In ceram Alumina blocks, all samples then veneered by veneering material accordingto manufacture instruction. Each group were further subdivided according to the type of finishing technique into three equal subgroups (n = 5): subgroup I (A): autoglazed samples (control group), subgroup II (G): re- glazed samples after surface adjustment and subgroup III (P): polished samples using the recommended polishing kitby the manufacturer. The crowns shaped samples were cemented on epoxy - resin dies and where subject to fracture load testing using universal testing machine. Scanning electron microscopy (SEM) was employed to examine the morphology of the ceramic surface after different finishing techniques. Data were collected and statistically analyzed. For In ceram zirconiacrowns the results showed the polishing technique had significanthighest mean load at failure than other techniques, whilefor In ceram Alumina crownsexhibited a significantly higher mean load at failure with the glazing procedures.The results also revealedthe In ceram zirconia crowns had significantly highest mean of surface roughness for re- glazing and glazing techniques, while the polishing technique showed the statistically significant highest mean of surface roughness for In ceram Alumina crowns. Finishing and polishing of In-ceram zirconia crowns results higher fracture resistance than that produced with the glazing and re-glazing procedures. In-ceram alumina crowns exhibited a significantly higher fracture resistance with the glazing procedures. Glazing and re- glazing for In-ceram zirconia crowns results in more rougher surfaces than that with finishing and polishing procedures

Issued also as CD