Effect of tooth whitening on dental restorative materials

Abstract

ObjectiveTo evaluate the effects of tooth whitening with 10% carbamide peroxide on the surface ultramorphology of three dental restorative materials. Materials and methodsThree materials were tested: (1) a reinforced zinc oxide-eugenol cement (IRM® Powder Zinc Oxide Eugenol, Dentsply, Konstanz, Germany), (2) a high copper amalgam with spherical particles (Ventura Finest®, Madespa SA, Toledo, Spain) and (3) a nanohybrid composite (EvoCeram Tetric®, Ivoclar Vivadent AG, Schaan, Liechtenstein). 6 specimens of each material (N=18) were inserted into silicone molds with circular cavities of 10mm×2mm. 3 specimens of each material were randomly assigned into the whitening or control groups. In the whitening group, the specimens were exposed to a 10% carbamide peroxide gel (Opalescence® PF 10%, Ultradent, South Jordan, UT, USA) for 14 consecutive days, 6h per day. In the control group, the specimens were exposed to distilled water. After 14 days stored at 37°C, all specimens were analyzed by scanning electron microscopy. ResultsThe specimens exposed to carbamide peroxide revealed an irregular surface, with cracks and pores. Specimens from all control groups showed a smooth surface. ConclusionThe 10% carbamide peroxide gel may cause changes in surface ultramorphology of the materials tested: reinforced zinc oxide-eugenol cement, amalgam and composite.