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