[The effect of tooth preparation design on the CAD/CAM all-ceramic coping crown's fitness].
OBJECTIVE
To study the effect of tooth preparation design on fitness of CAD/CAM all-ceramic coping crown.


METHODS
The tooth preparation comprised 2 types of occlusal convergence (10 degrees, 20 degrees), 2 margin forms (shoulder, chamfer). The MC coping were milled by Cerec 2 CAD/CAM system, cemented, embedded, sectioned, and measured at 10 sites to obtain the data of margin, shoulder, axial surface, occlusal surface fitness.


RESULTS
The coping's fitness was influenced by convergence angle and margin form. The coping's fitness was very nice (101.7 approximately 127.9) microm when the coping with 20 degrees occlusal convergence angle. Those coping with 20 degrees occlusal convergence and chamfer margin in tooth preparation provided the best fitness, its cement film thickness in margin was (40.1 +/- 11.8) microm.


CONCLUSIONS
The 20 degrees occlusal convergence and chamfer margin can be used for CAD/CAM all-ceramic crown in clinical application.
Zhao
Yun-feng
YF
Department of Prosthodontics, West China School of Stomatology, Sichuan University, Chengdu 610041, China.
Wang
Hua-rong
HR
Li
Yong
Y
D017076:Computer-Aided Design; D003442:Crowns; D003776:Dental Porcelain; D017267:Dental Prosthesis Design; D006801:Humans; D019231:Tooth Preparation, Prosthodontic
D003776:Dental Porcelain