Impact strength of an experimental polyurethane- based polymer

Abstract

The impact strength of a newly developed experimental polyurethane-based polymer which is derived from palm oil (Experimental PU) was compared with denture polymers; heat-cured and self cured polymethyl methacrylate (PMMA) and ? Eclipse , light-activated urethane dimethacrylate prosthetic resin system. Ten specimens were ? prepared using heat-cured PMMA (Meliodent Heat Cure, Heraeus Kulzer, Germany), self cured PMMA ? (Meliodent Rapid Repair, Heraeus Kulzer, ? Germany), Eclipse baseplate resin (Dentsply, USA) and Experimental PU material. Specimens were prepared following manu- facturer?s instructions except for the Experimental PU material where it was prepared in bulk and sectioned to the desired dimension, 64 x 6 x 4 mm. A ?V? notch of approximately 0.8mm in depth was machine cut across the 6mm width. Prior to the Charpy type impact test, specimens were soaked in a water bath for 50 hours at 37?C. ? Eclipse baseplate resin showed the highest 2 impact strength (2.73 kJ/m ?0.54) followed by ? 2 Meliodent Rapid Repair (2.50kJ/m ?0.65), ? 2 Meliodent Heat Cure (1.96kJ/m ?0.42) and 2 Experimental PU (1.04kJ/m ?0.29). One-way ANOVA showed significant interaction between materials (p<.05) and Tukey HSD revealed that Experimental PU exhibited significantly lower impact strength compared to other materials. ? Meliodent Rapid Repair was not significantly ? ? different from Meliodent Heat Cure and Eclipse baseplate resin. It can be concluded that the Experimental PU ? exhibited the lowest impact strength while Eclipse baseplate resin the highest.