The Comparison Of The Fitness About Three Kinds Of All Ceramic Coping Crown

ObjectiveTo compare the marginal fitness about three kinds of all ceramiccrown,and then to select the best retoration material in clinic.MethodsA metal model of the first premolar was prepared and replilated in totwenty plaser castes.Divide them into4group in random,fracture all ceramiccoping crown with three ceramic materials: die-casting ceramic, cerec3Dceramic and GI-II ceramic.All ceramic crowns adhered to the correspondingmodel and compare their adaption through statistical analysis.ResultsSuitability of the edge of the nickel-chromium metal ceramic andall-ceramic of the IPS-Empess ceramics, the Cere3system, the GI-IIall-ceramic, respectively (88.2±21.2μm),(65.1±11.1μm),(87.4±8.9μm).(108.9±12.5μm), shoulder suitability, respectively (109.9±12.4μm)(87.0±11.0μm),(107.9±21.0μm),(117.4±15.5μm) suitable axial plane,respectively (41.8±8.0μm),(62.6±12.0μm),(93.9±35.5μm),(116.5±6.2μm).Occlusal surface is suitable, respectively (106.9±14.0μm)(64.6±27.0μm),(213.2±29.0μm),(107.3±11.2μm). Marginal fit of a variety of all-ceramicsystems have significant differences (P <0.05), IPS-Empress2systemproduced the highest edge of the gap between the edge of the gap in the GI-IIsystems to produce all-ceramic crowns. ConclusionsIPS-Empess2ceramic coping crown has the highest accuracy of fitness.GI-II ceramic coping cown has the lowest accuracy of fitness. All the groupsmeets the need of clinical application.