Effect of core∶dentin thickness ratio on the flexure strength of IPS Empress Ⅱ heat-pressed all-ceramic restorative material
- VernacularTitle:基底瓷与饰瓷的厚度比对IPS EmpressⅡ热压铸陶瓷抗弯强度的影响
- Author:
Yihong LIU
;
Hailan FENG
;
Yiwang BAO
;
Yan QIU
- Publication Type:Journal Article
- Keywords:
Dental porcelain;
Dental prosthesis;
Biomechanics
- From:
Journal of Peking University(Health Sciences)
2004;0(01):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To evaluate the effect of core∶dentin thickness ratio on the flexure strength, fracture mode and origin of bilayered IPS Empress Ⅱceramic composite specimens. Methods: IPS EmpressⅡ core ceramic, dentin porcelain and bilayered composite specimens with core∶dentin thickness ratio of 2∶1 and 1∶1 were tested in three-point flexure strength. Mean strengths and standard deviations were determined. The optical microscopy was employed for identification of the fracture mode and origin. Results: The flexure strength of dentin porcelain was the smallest (62.7 MPa), and the strength of bilayered composite specimens was smaller than single-layered core ceramic(190.2 MPa). The core∶dentin ratio did not influence the strength of bilayered composite specimens. The frequency of occurrence of bilayered specimen delaminations was higher in the group of core∶dentin thickness ratio of 1∶1 than in the group of 2∶1. Conclusion: IPS Empress Ⅱcore ceramic was significantly stronger than veneering dentin porcelain. Core∶dentin thickness ratio could significantly influence the fracture mode and origin, and bilayered IPS Empress Ⅱceramic composite specimens showed little influence in the fracture strength.
