Abstract
AIM: The study aims to assess the effect of surface treatments by chemical agents on the retentive strengths of crowns fabricated from polymethylmethacrylate (PMMA) reinforced with graphene nanoparticles adhesively bonded to abutments after thermocycling. SETTINGS AND DESIGN: In vitro comparative study. MATERIALS AND METHODS: This study is composed of four groups - one control, one treated with 99% pure etchant acetone solution, one treated with 15 wt% potassium hydrogen fluoride solution, and the last group treated with a combination of both solutions. RESULTS: The results showed that the mean load in Group A is 228.46±3.16, Group B is 252.57±7.14, Group C is 184.51±6.61, and Group D is 211.03±2.54. The mean score is highest for Group B followed by Group A and Group D, and it is least for Group C. One-way analysis of variance (ANOVA) detected highly significant differences (p<0.01) among the four groups. CONCLUSION: It can be concluded that acetone is the best chemical etchant solution for crowns fabricated from G-CAM discs (Graphenano Dental, Graphenano Nanotechnologies, Spain).