Influence of preparation height and cement space on the fit and retention of computer aided design/computer aided manufacturing zirconia crown.
- Author:
Shuang XI
1
;
Zi-Xiao WU
1
;
Cui-Cui GAO
1
;
Yu-Chen MENG
1
;
Dan-Dan PEI
1
;
Yi LU
1
Author Information
- Publication Type:Journal Article
- Keywords: cement space; computer aided design/computer aided manufacturing zirconia crown; fit; preparation height; retention
- MeSH: Computer-Aided Design; Crowns; Dental Porcelain; Dental Prosthesis Design; Zirconium
- From: West China Journal of Stomatology 2020;38(3):263-269
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE:To investigate the effects of preparation height and cement space on the fit and retention of computer aided design (CAD)/computer aided manufacturing (CAM) zirconia crown, and to provide reference for the clinical design and fabrication of CAD/CAM crowns.
METHODS:3D printing system was used to fabricate resin abutment teeth with convergence angle of 2° and height of 1-3 mm. The models' optical impressions were collected by the three-shape scanner. Then, the cement spaces were set by Cradle CAD/CAM system at 10-50 μm to create an all-ceramic zirconia crown. The fit of the crowns was measured by using silicone rubber interstitial impression method. The retention of the crowns was measured by pull-off test with uniaxial tensile force after the crown was bonded. The data were analyzed by SPSS 22.0 soft-ware.
RESULTS:When the preparation height was fixed, the fitness values of different cement space groups have statistical difference (P< 0.05), whereas the retention values of different cement space groups have no statistical difference (P>0.05). The fitness values of different preparation height groups have no statistical difference (P>0.05), and the retention values of different preparation height groups have statistical difference (P<0.05) when the cement space was fixed. No interaction was observed between the cement space and the preparation height (P>0.05).
CONCLUSIONS:When cradle CAD/CAM system is used to create a full crown in the clinic, the preparation height should be set to more than 3 mm, and the cement space should be set at 30 μm.
