Marginal and internal adaptation of CAD/CAM zirconia copings made from In Coris{u2122} Sirona{u2122} blocks influenced by digital impression techniques / Mohamed Ahmed Mohamed Abuleila ; Supervised Omaima Elmahalawi

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

Aim: To investigate the effect of different digital scanning techniques on marginal and internal adaptation and evaluation of the effect of different digital scanning techniques on marginal and internal adaptation Background: Computer aided design and computer aided manufacturing (CAD/CAM) technologies were developed as an alternative to the conventional ceramic restoration fabrications method. For the acquisition of digital images of teeth, different procedures have been described: indirect digitization of plaster cast or digitization of impressions and direct intraoral digital impression. Digital work has been proposed to improve treatment planning. Methods: The tooth samples were mounted in acrylic resin block holding the tooth with its long axis parallel to the tube to allow accurate centralization of the tooth during tooth preparation.The samples were divided into four groups as follows: Group A: consisted of 7 indirect scans of the conventional impression with the Cerec inEosx5. Group B: consisted of 7 indirect scans of the casts obtained from impressions with the Cerec inEosx5. Group C: consisted of 7 direct master model scans with the Cerec Bluecam. Group D: consisted of 7 direct master model scans with the Cerec Omnicam. The vertical marginal gap distance between the coping and the tooth was measured using ESEM (Environmental scanning electron microscope). Measurements were made at ten equidistant points for each surface of the coping and then the data obtained were collected, tabulated and subjected to statistical analysis, measurements for internal adaptation was also done using ESEM at set points

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