RESUMO
Physical and mechanical properties of resins are of a great concern, and many approaches have been used to strengthen acrylic resin dentures. This study measured the effect of addition of rubber modified- montmorillonite [MMT) composite by different ratios to heat cured acrylic resin on the micro-hardness, Young's modulus, surface roughness and glass transition temperature. Fifteen acrylic resin test specimens were prepared and reinforced with rubber modified MMT (1% composite, 1% composite with double rubber content and 3% composite). The control group consists of five specimens with no reinforcement. These specimens were tested as regard; -micro-hardness, Young's modulus, surface roughness and glass transition temperature. The results of the present study demonstrated that, Vickers hardness values of acrylic resin denture base were decrease after addition of rubber MMT -composite at any ratio. The Young's modulus after addition of 3% rubber MMT-composite was nearly similar to that of control group. While adding 1% composite and 1% composite with double rubber content produce significant reduction in the Young's modulus values. As regards to surface roughness there was significant increase in the surface roughness after addition of 3% composite. Furthermore there was significant elevation of the glass transition temperature after addition of 3% rubber MMT-composiu;. While the glass transition temperature of the other ratios were nearly similar to that of the control group