Effect of aging in artificial saliva on the shear bond strength of resin composite

Abstract

INTRODUCTION: Artificial saliva as an in vitro aging medium may be an effective method of simulating the clinical degradation of resin composite restorations. The composition and desirable properties of artificial saliva are not yet standardised. Incorporation of oral bacteria may more closely approximate the intra-oral effect of saliva on composite restorations. Surface deterioration on an old broken restoration repaired with fresh composite may result in a weak adhesive interface, measureable, in vitro, by a shear bond strength test AIM OF THE STUDY: To evaluate whether artificially aged composite affects the shear bond strength of the adhesive interface with fresh composite. MATERIALS AND METHODS: A silicone mould was used to fabricate 240 composite cylinders. 120 were aged in a solution of artificial saliva for 28 days. The remainder served as controls. The specimens were divided into seven groups of twenty, each group being subjected to a different repair protocol. Shear bond strength testing was then carried out on the repaired composite blocks. RESULTS: Aging in artificial saliva resulted in a reduction of 15.04% to 21.1% in shear bond strengths compared with un-aged composite CONCLUSION: Composite samples aged in artificial saliva had a significantly weaker repair interface compared with non-aged samples