To date, the management of fractured dentures made from high-impact acrylic polymers is challenging. Hence this study is aimed to evaluate fracture force, toughness, and deflection on three types of repaired injection-molded polymethyl methacrylate thermoplastic denture base resins. In this in-vitro study, the sample size was estimated to 20 samples per group (group A, B, and C) using G*power 3.0.10 software with power 80% and alpha error of 5%. So, a total of 60 high-impact injection-molded acrylic resin samples (39mm x 4mm x 8mm) were prepared and a pre-crack was made with a diamond disc to a depth of (3.0 ± 0.2) mm along the marked centreline. Repair of the fractured segments was done with Probase cold, Triplex SR cold, and Lukafix light cure resin. A three-point bending test was carried out to test the repaired site, and the obtained values were statically analyzed with one-way ANOVA and Tukey’s post hoc test (α ≤ 0.05). The statistical analysis has shown significant differences in flexural force, deflection, and fracture toughness between groups. The increase in fracture toughness was observed in group A, which was 245.06N, the deflection was 0.14cm and flexural strength was 24.0 Mpa. The fracture force, deflection, and toughness were found to be significant in samples repaired with auto polymerizing PMMA resin. Hence the study concludes that auto polymerizing resin can be better used in repair auto polymerizing PMMA resin when compared to other resins.
