TY - JOUR ID - TI - An in vitro evaluation of fit of the crowns fabricated by zirconium oxide-based ceramic CAD/CAM systems, before and after porcelain firing cycles and after glaze cycles AU - Sattar J. A. Hmedat ستار حميدات AU - Adel F. Ibraheem عادل فرحان ابراهيم PY - 2013 VL - 25 IS - 1 SP - 43 EP - 48 JO - Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد SN - 18171869 23115270 AB - Background: The objective of this in vitro study was to evaluate the vertical marginal fit of crowns fabricated withZrO2 CAD/CAM, before and after porcelain firing cycles and after glaze cycles.Materials and Methods: An acrylic resin model of a left maxillary first molar was prepared and duplicated to haveNickel-Chromium master die. Ten die stone dies were sent to the CAD/CAM (Amann Girrbach) for crownsfabrication. Marginal gaps along vertical planes were measured at four indentations at the (mid mesial, mid distal,mid buccal, mid palatal) before (Time 0) and after porcelain firing cycles (Time 1) and after glaze cycles (Time 2)using a light microscope at a magnification of ~100. One way ANOVA LSD tests were performed to determinewhether the mean and standard deviation of sub group Time 2.Results: The mean values of the ZrO2 CAD/CAM Time 0 were (6.77ƒÊm), Time 1(8.75ƒÊm) and Time 2(10.62 ƒÊm). Oneway ANOVA test revealed highly statistical significance(P<0.01). LSD test results showed that there is highly significantdifference between time (0) and time (2), while there is no any significant difference between time (0) and time (1),and between time (1) and time (2).Conclusions: Within the limitations of this study, it was concluded that the ZrO2 CAD/CAM demonstrated acceptablemarginal fit; The porcelain firing and the glaze firing cycles affected the marginal gap

ER -