الفهرس | Only 14 pages are availabe for public view |
Abstract The aim of this in-vitro study was to evaluate the vertical marginal gap distance and internal adaptation between e max supestracturs and e max hybrid abutments constructed by CAD/CAM and heat pressing techniques. 14 Dummy implants were placed in epoxy resin blocks using paralleling device then titanium bases were screwed to the dummy implants . The samples were randomly assigned into two study groups (n=7) for each group according to the construction technique; group I: e.max CAD/CAM fabricated hybrid abutments and superstructures , group II: e-max heat pressing fabricated hybrid abutments and superstructures . For the CAD/CAM group , the titanium base was scannedand the abutment was designed on the DWOS software then milled on a 5 axis machine. For the heat pressing group, wax pattens were fabricated by CAD /CAM technique using CAD wax disck.The wax patterns were then invested and pressed from e max press ingots . The produced cermic abutments of both groups were evaluated on their crosponding titanum bases then cemented to it using adhesive resin cement . All Superstrucures were designed as monolithic upper frist premolar ,half of which were fabricated by the CAD/CAM technique and the other half by the heat pressing technique. Vertical marginal gap distance measurements between each abutment and its corresponding superstructure were recorded at 36 points (9 points/surface) using a digital microscope . Internal adaptation was measured using silicon replica technique which was sectioned bucco-lingually and mesio-distally then measurements were taken using a digital microscope at predetermined points. The heat pressing group showed a statistically significat lower marginal gap distance results than the CAD/CAM group.On the other hand, samples of the CAD/CAM group showed statistically significat higher internal adaptation than samples of the heat pressing group. |