• Sunbul, Hanan Al
• Silikas, Nikolaos
• Watts, Dc.

Abstract

Objectives. To investigate a set of resin-composites and the effect of their composition onpolymerization shrinkage strain and strain kinetics, shrinkage stress and the apparentelastic modulus.Methods. Eighteen commercially available resin-composites were investigated. Three spec-imens (n = 3) were made per material and light-cured with an LED unit (1200 mW/cm2) for20 s. The bonded-disk method was used to measure the shrinkage strain and Bioman shrink-age stress instrument was used to measure shrinkage stress. The shrinkage strain kineticsat 23◦C was monitored for 60 min. Maximum strain and stress was evaluated at 60 min. Theshrinkage strain rate was calculated using numerical differentiation.Results. The shrinkage strain values ranged from 1.83 (0.09) % for Tetric Evoceram (TEC) to4.68 (0.04) % for Beautifil flow plus (BFP). The shrinkage strain rate ranged from 0.11 (0.01%s−1)for Gaenial posterior (GA-P) to 0.59 (0.07) %s−1for BFP. Shrinkage stress values ranged from3.94 (0.40) MPa for TET to 10.45 (0.41) MPa for BFP. The apparent elastic modulus ranged from153.56 (18.7) MPa for Ever X posterior (EVX) to 277.34 (25.5) MPa for Grandio SO heavy flow(GSO).Significance. The nature of the monomer system determines the amount of the bulk contrac-tion that occurs during polymerization and the resultant stress. Higher values of shrinkagestrain and stress were demonstrated by the investigated flowable materials. The bulk-fillmaterials showed comparable result when compared to the traditional resin-composites.

Topics

• composite
• resin