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

Aim: To investigate the effect of glazing versus polishing on the color difference between natural teeth and all ceramic crowns made from celtra press (zirconia reinforced lithium silicate ceramic). Methodology: 20 teeth esthetic zone requiring full coverage crown -with their contralateral are sound and not severely discolored - were prepared to receive an all ceramic crown. The crowns divided into two Groups: Group I: Teeth received crowns fabricated from glazed Celtra Press ceramic Group II: Teeth receiving crowns fabricated from polished Celtra Press (Dentsply Sirona). The color difference xE (perceptibility threshold) was measured using intraoral spectrophotometer and evaluated for each group. Shade matching to the contrallateral tooth was evaluated by 2 experienced prosthodontists according to modified United States public health service (USPHS) criteria as Alpha (Excellent), Bravo (Acceptable), Charlie (Acceptable but modifications needed), and Delta (Unacceptable). Patient satisfaction of the two groups assessed using the Visual Analogue Scale (VAS) which is Binary and documented in chart including number of satisfied and unsatisfied. Results: Patient satisfaction was graded according to the visual analogue scale (VAS). There was no statistically significant difference between (Group I) and (Group II) where (p=1) as all patients were satisfied. Color change was recorded according to the (xE) ,It was found that polished Celtra Press group recorded statistically non-significant higher color changes than glazed Celtra Press group as indicated by paired t-test (t=0.941, P=0.3715 >0.05). shade matching was graded according to USPHS, where in Glazed Celtra Press group predominantly of the patients stated Alpha score(80%)while minority showed Bravo score(20%) with no record for Charlie and Delta scores (0%). In Polished Celtra Press group all of patients informed Bravo score100% with no record for Alpha, Charlie and Delta scores (0 %).This was statistically significant as proved by chi square test (p = 0.0014 <0.05)

Issued also as CD