Effects of aluminum oxide addition on the surface roughness and hardness of acrylic resin denture base

Problem: Acrylic dentures frequently fracture during service due to their poor strength characteristic. Several attempts have been carried out to improve strength of acrylic by addition some materials such as fibers or Aluminum oxide. The purpose of this study was to evaluate the effect of adding Aluminum oxide (AL2O3) on the surface roughness and hardness of heat cure acrylic resin denture base material. Materials and Methods: 60 specimens were made from the heat cure acrylic resin denture base after being cured in microwave oven, 30 specimens prepared for surface roughness test and these where subdivided according to concentration of AL2O3 into three subgroups as follow: Group (A): 10 specimens of acrylic resin without AL2O3 (control group) Group (B): 10 specimens of acrylic resin+2.5% by weight AL2O3 Group (C): 10 specimens of acrylic resin +5% by weight AL2O3 30 specimens prepared for surface hardness test and these where subdivided according to concentration of AL2O3 into three subgroups as follow: Group (A): 10 specimens of acrylic resin without AL2O3 (control group) Group (B): 10 specimens of acrylic resin+2.5% by weight AL2O3 Group (C): 10 specimens of acrylic resin +5% by weight AL2O3 The average of the surfac e roughness of the samples has been determined with using the profilometer (surface roughness tester)¸ also the average of the sur face hardness of the samples has been determined with using surface hardness tester (digital micro Vickers). Result: The results show ed that there were no statistically significant differences in t he surface roughness and hardness. Conclusion: The addition of aluminum oxide in low percentage not affected on the surface roughness and hardness of heat cure acrylic resin.