J Korean Acad Prosthodont.  2000 Feb;38(1):38-49.

The Effects Of Thermocycling On The Bond Strength Between Cobalt-Chromium Alloy And Denture Base Resin

• Lee SY
• Vang MS

Abstract

The purpose of this study was to evaluate the effects of thermocycling on the shear bond strength of Co-Cr alloy to denture base resin. PMMA denture base resin such as heat-cured Vertex-RS , self-cured Vertex-SC and 4-META denture base resin such as heat-cured Meta-Dent , self-cured Meta-Fast was bonded to Co-Cr alloy. Samples were divided into 3 groups : no thermocycling group as control, thermocycling between 5degrees C and 55degrees C with 15 second dwell time as group 1, thermocycling with 1 minute dwell time as group2. The shear bond strength was measured and the interface between metal and resin was observed by SEM. The results were as follows. 1. The shear bond strength decreased significantly according to thermocycling and dwell time(P<0.001). 2. The bond strength of Co-Cr alloy and 4-META denture base resin was significantly higher than that of Co-Cr alloy and PMMA denture base resin(P<0.001). 3. IN SEM, there was no gap in control group, but there was much and large gap in group 1, 2. The longer dwell times, the lower bond strength. PMMA denture base resin had more gap than 4-META denture dwell times, the lower bond strength. PMMA denture base resin had more gap than 4-META denture base resin in the interface. These results revealed that thermocycling decreased the bond strength between Co-Cr alloy and denture base resin and dwell time of thermocycling changed the effect of thermocycling. The results suggested that oral temperature change affect the bond strength of prosthesis.

MeSH Terms

Alloys*
Denture Bases*
Dentures*
Polymethyl Methacrylate
Prostheses and Implants
Alloys
Polymethyl Methacrylate