Author/Authors :
Farzin، Mitra نويسنده Dept. of Prosthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran. , , Khaledi، Amir AliReza نويسنده Department of Prosthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran , , Malekpour ، Behnam نويسنده Postgraduate Student, Dept. of Orthodontic, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran. , , Naseri، Mohammad-Hassan نويسنده ,
Abstract :
Statement of the Problem: The success of metal- ceramic- restorations (MCR) depends on the presence of strong bond between porcelain and metal substructure.
Purpose: The purpose of this study was to evaluate the effect of hot pressing technique on the bond strength of a metal-porcelain composite in comparison to layering technique.
Materials and Method: Thirty Nickel-Chromium specimens were produced by two methods; conventional porcelain layering on metal and hot pressing (n=15). Bond strengths of all specimens were assessed by the means of three–point bending test according to ISO 9693: 1999 (E) instructions. The data were analyzed using Students t-test (p < 0.001).
Results: The mean ± SD bond strength of conventional and hot pressing technique was 48.29 ± 6.02 and 56.52 ± 4.97, respectively. Therefore, the conventional layering technique yielded significantly lower mean bond strength values than hot pressing technique (p < 0.001).
Conclusion: This study showed that it is possible to improve metal–porcelain bond strength significantly by applying an overpressure during porcelain firing.
