Examining clinically surface wear amount of crown restorations produced by CAD&CAM method using new jeneration restorative material with 3 dimensional image aligning

Monolithic single crown restorations prepared from resin matrix ceramic material and glass matrix materials through CAD/CAM have been safely used in dentistry during recent years. These restorative materials are required not to produce any wearing off both on the teeth and as well as on itself. Therefore, the hardness level of material and structural resistance is clinically very important. The aim of the study is to examine the amount of clinical wearing off during 6 months in the single crown restorations made of the first molar teeth from 4 different restorative materials and in the natural teeth that come to the occlusion using 3D image alignment method. People who reported to Ege üniversity school of dentistry department of prosthodontics, within an age limit of 18-50 years, without any systemic deficiency, no loss of periodontal support tissue, with crown indications and natural teeth that come to the occlusion have been included in this study. A total of 24 single crown restorations have been completed on first molar of these individuals. We utilised following materials. As single crown materials lithium disilicate based IPS E-max CAD, consisting lithium silicate and hardened with a little bit zirconium Vita Suprinity CAD, as resin matrix ceramic material GC Cerasmart and Vita Enamic CAD blocks have been used in this study. Single crowns designed and manifactured by "Cerec 3D Bluecam" have been cemented by using dual-cure resin cement Variolink Esthetic DC. İmmediately after cementation, digital measurement of crown restorations and the enamel surfaces which are facing the occlusion of all patients with"Cerec 3D Bluecam" inner mouth probe have been obtained in third and sixth months. These digital measurements have been placed on each other with "David-Laserscanner (V3.10.4)" computer program. Volume loss of wearing off during the initial to 3-month period as well as 3 to 6-month period have been calculated with "Siemens Unigraphics NX 10" computer program. Statistical analysis of values obtained have been accomplished by Repeated Measures for ANOVA. According to the findings obtained during a 6-month period, there are no significant statistical differences of the glass matrix group materials and resin matrix group materials in terms of affect on restoration / enamel wearing off (p  0,05). When assessed as groups, while there is no significant findings in glass matrix group (p > 0.05), it is observed that, there is a significant findings in between resin matrix group materials (p < 0,05). Although GC Cerasmart and VITA Enamic materials based in same groups, they appeared to exhibit different wearing characteristic. In line with the results of our work, for the resin matrix materials we suggest that it will be more proper to decrease the polishing from once every 6 months to once every 3 months in terms of wearing off effect. When compared to resin matrix materials, the glass matrix materials showed less wear on both on their own and on the surface of the enamel they come to the occlusion with. Keywords: In-vivo wearing off, antagonist wearing off, resin matrix ceramic crowns, glass ceramic crowns, CAD / CAM.