Comparative study of the fatigue strength of five acrylic denture resins

The aim of this in vitro study was to compare the fatigue resistance of three kinds of heat-polymerized acrylic resins (conventional heat-polymerized, rapid heat-polymerized, high impact acrylic resin), a kind of visible light-cured resin and a kind of self-cured acrylic resin. A total of 60 notched and un-notched specimens (65 mm × 10 mm × 3 mm) were fabricated, 12 from each material. The fatigue resistance was measured by applying repeated three-point bending deflection to the specimens. For statistical analysis, Kruskal–Wallis test followed by Dunn’s multiple comparison tests were used. The Kruskal–Wallis test revealed significant differences in the fatigue resistance among some groups ( p < 0.05 ). Conventional- and rapid-heat polymerized resins had lower fatigue resistance values than heat-polymerized high impact acrylic resin, but the differences were statistically non-significant according to Dunn’s test ( p > 0.05 ). High impact acrylic resin was also found to have significantly higher fatigue resistance value than that of self-cured resin and light-cured resin ( p < 0.05 ). Further, there was no statistically significant difference between the mean fatigue resistance value of visible light-cured resin and self-cured resin ( p > 0.05 ).