Influence of artificial aging and ZrO2 nanoparticle-reinforced repair resin on the denture repair strength
Mohammed M. Gad, A Rahoma, R. Abualsaud, Ahmad M. Al‐Thobity, Sultan Akhtar, Intisar Ahmad Siddiqui, FA. Al-Harbi
Abstract
Background: The purpose of this study was to evaluate the effect of aging process on the tensile strength (TS) of repaired acrylic denture base using ZrO 2 nanoparticles (nano-ZrO 2 )-reinforced autopolymerized resin. Material and Methods: A total of 240 heat-polymerized acrylic resin specimens (n=10) were prepared and sectioned creating 2 mm-repair-gap. Autopolymerized acrylic resin, pure and modified with 2.5, 5, and 7.5wt% nano-ZrO 2 were used for specimens repair. TS of repaired specimens were measured using the universal testing machine after water immersion at 37 o C for 2, 7 and 30 days. At each time interval, half the immersed specimens underwent thermo-cycling aging process (5000 cycles at 5/55C) before TS testing. One-way ANOVA and Tukey-Kramer multiple-comparison tests were used for data analysis at =0.05. Results: Aging process for all groups showed significant differences in TS between unreinforced and nano-ZrO 2 reinforced groups (p<0.05). Within immersed nano-ZrO 2 -reinforced specimens, 5% group immersed for 30-days showed the highest significant TS value (p<0.05). With regards to thermocycling, 5% group showed the highest TS values after 2-days and 30-days groups while after 7-days, significant differences were found between 2.5% group and 5% and 7.5% groups (p0.05). SEM images analysis displayed the ductile fracture type for nano-ZrO 2 reinforced groups. Conclusions: In summary, 5.0%-nano-ZrO 2 addition to repair resin showed an improvement in tensile strength of repaired acrylic resin with different aging processes.