Abstract
To study the bonding durability of metal-resin bonding systems, thermocycling test is one of the most important methods. However, researchers have adopted various kinds of test conditions such as specimen size, shape, immersion period for each bath and number of thermocycles, etc., and it is difficult to compare the results of thermocycling test with each other.
The immersion bath of higher temperature is also an important factor. However, there is no established temperature and the values reported in the literature show substantial variation and are distributed from 40 to 70°C.
In this study, adhesive specimens were constructed applying three bonding systems for resin -retained dental alloy. Completed specimens were thermocycled 20, 000 times at three hot bath temperatures of 50°C, 60°C and 70°C. Tensile and shear adhesive bond strengthwere then measured.
Increasing the immersion temperature, bond strength of all specimens decreased.However, the difference in bond strength between 50°C and 60°C specimens was not statistically significant at the p<0.01 level. At the temperature of 70°C, VBATDT primer system showed more durability than traditional adhesion systems which need oxidation surface treatment.
