NIGERIAN JOURNAL OF CLINICAL PRACTICE, vol.19, no.5, pp.585-590, 2016 (SCI-Expanded)
Objectives: The aim of the present study was to compare two different bond strength test methods (tensile and microtensile) in investing the influence of erbium, chromium: yttrium-scandium-gallium-garnet (Er, Cr: YSGG) laser pulse frequency on resin-enamel bonding. Materials and Methods: One-hundred and twenty-five bovine incisors were used in the present study. Two test methods were used: Tensile bond strength (TBS; n = 20) and micro-TBS (mTBS; n = 5). Those two groups were further split into three subgroups according to Er, Cr: YSGG laser frequency (20, 35, and 50 Hz). Following adhesive procedures, microhybrid composite was placed in a custom-made bonding jig for TBS testing and incrementally for mTBS testing. TBS and mTBS tests were carried out using a universal testing machine and a microtensile tester, respectively. Results: Analysis of TBS results showed that means were not significantly different. For mTBS, the Laser-50 Hz group showed the highest bond strength (P 0.05), and increasing frequency significantly increased bond strength (P 0.05). Comparing the two tests, the mTBS results showed higher means and lower standard deviations. Conclusion: It was demonstrated that increasing mTBS pulse frequency significantly improved immediate bond strength while TBS showed no significant effect. It can, therefore, be concluded that test method may play a significant role in determining optimum laser parameters for resin bonding.