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

• Published in: Dental materials Vol. 28; no. 4; pp. e27 - e34
• Main Authors: Pabis, Lucas V.S, Xavier, Tathy A, Rosa, Ecinele F, Rodrigues, Flávia P, Meira, Josete B.C, Lima, Raul G, Filho, Leonardo E. Rodrigues, Ballester, Rafael Y
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.04.2012
• Subjects: Advanced Basic Science; Composite Resins - chemistry; Dental Bonding; Dental stress analysis; Dental Stress Analysis - methods; Dentistry; Finite Element Analysis; Glass; Materials Testing; Materials testing biomechanics; Mechanical stress; Polymerization; Resin-composite; Stress, Mechanical; Surface Properties; Dental bonding; Dental stress analysis; Finite element analysis; Materials testing biomechanics; Mechanical stress; Resin-composite
• ISSN: 0109-5641; 1879-0097
• DOI: 10.1016/j.dental.2012.01.004

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 < 0.01, Pearson's test) between the stress-peak and the coverslip deflection when the resin-composites were grouped by diameter was found for diameters of 2 and 4 mm. The stress-peak of the whole set of data showed a logarithmic correlation with the bonded resin-composite volume ( p < 0.001, Pearson's test), but did not correlate with the C-Factor. 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.