Abstract
This study assessed the impact of surface treatments and repair resin reinforcement with zirconium oxide nano-particles (nano-ZrO2) on flexural strength (FS) of repaired denture base. A total of 320 heat-polymerized acrylic resin specimens were prepared and sectioned creating 2-mm gap. According to repair surface treatment, specimens were distributed into four groups: I) methyl methacrylate (M); II) alumina-blasted (AB); III) AB+silane coupling agent (SC); and IV) AB+methacrylate based composite bonding agent (MA). Groups were subdivided into 4 (n=20) according to nano-ZrO2 concentration (0, 2.5, 5, 7.5 wt%). Half the specimens were thermo-cycled before testing. FS was determined by three-point bending test. Statistical analysis was done using ANOVA and Tukey-Kramer multiple comparison tests, with a=0.05. Alumina-blasting+(SC) or (MA) significantly increased FS of repaired specimens compared to control (p<0.05). All surface-treated specimens combined with nano-ZrO2 reinforced repair resin significantly increased FS.