A method to investigate the shrinkage stress developed by resin-composites bonded to a single flat surface.

Abstract Objectives To purpose a method for predicting the shrinkage stress development in the adhesive layer of resin-composite cylinders that shrink bonded to a single flat surface, by measuring the deflection of a glass coverslip caused by the shrinkage of the bonded cylinders. The correlation between the volume of the bonded resin-composite and the stress-peak was also investigated. Methods A glass coverslip deflection caused by the shrinkage of a bonded resin-composite cylinder (diameter: d  = 8 mm, 4 mm, or 2 mm, height: h  = 4 mm, 2 mm, 1 mm, or 0.5 mm) was measured, and the same set-up was simulated by finite element analysis (3D-FEA). Stresses generated in the adhesive layer were plotted versus two geometric variables of the resin-composite cylinder (C-Factor and volume) to verify the existence of correlations between them and stresses. Results The FEA models were validated. A significant correlation ( p p Significance The described method should be considered for standardizing the stress generated by the shrinkage of resin-composite blocks bonded to a single flat surface.