레진시멘트 두께가 세라믹/시멘트 중층 시편의 굴곡강도에 미치는 영향

Abstract

1. Objective The purpose of this study was to evaluate the effect of resin cement thickness on the flexural strength (FS) of ceramic/cement bilayers using a three-point bending test.

2. Methods Variolink N (Ivoclar Vivadent) was cemented on the ground surface of IPS Empress CAD ceramic (Ivoclar Vivadent). A total of 56 specimens were prepared with resin cement thickness in the range from 75 to 425 µm. The FS was measured using a three-point bending test with the resin cement facing downward. Data were analyzed using correlation coefficient, and the Weibull distribution.

3.Results The FS was 119.2 MPa (119.23 ± 41.069). Correlation between the cement thickness and the FS was not significant (r = 0.140, p =0.303). The Weibull modulus was 3.581 (90% confidence interval, 2.75 - 4.41). Characteristic strength was 132.3 MPa (90% confidence interval, 57.7 - 179.8). No correlation could be established between the observed fractured specimen patterns.

4.Conclusions There was no significant correlation between the thickness of resin cement and the flexural strength of ceramic/cement bilayer. The small Weibull modulus could be attributed to the low wettability of the resin cement. The effect of cement thickness on the flexural strength of ceramic/cement bilayer was negligible.