Effect of Incorporation of Silver Nitrate on Transverse Strength and Impact Strength of Autopolymerizing Acrylic Resin

Abstract

background: Autopolymerizing acrylic resin has multiple uses in dentistry such as, record base, orthodontics appliances, denture repair and other. Thedegree of polymerization of cold cured acrylic resin is not as complete as that achieved using heat cured system which leads to a higher degree of un-reacted residual monomer, which act as a plasticizer which results in high transverse deflection values lowering the transverse strength of the resin.Aim of the study: This study investigated the effect of the addition of different concentrations of silver nitrate (AgNO3) on transverse strength and impact strength of autopolymerzing acrylic resin.Materials and methods: A total of 80 specimens were prepared, 40 specimens were fabricated with dimensions of (64×10×2.5) mm to conduct the transverse strength test while the remaining 40 specimens were fabricated with dimensions of (80×10×4) mm to perform the impact strength test. 10 specimens of each group were fabricated from conventional autopolymerized acrylic resin while the remaining 30 specimens were fabricated from modified autopolymerized acrylic resin. Concentrations of 9.375,15 and 60 ppm of silver nitrate were used to modify the autopolymerized acrylic resin, 10 specimens of each concentration in each group were used.Results: The results of this study showed that the modified autopolytmerized acrylic had non-significant difference in transverse strength values for all concentrations of silver nitrate; while there was a significant difference in impact strength values for (15 and 60 ppm) concentrations of silver nitrate and non-significant difference in impact strength values for (9.375 ppm) concentration of silver nitrate .Conclusions: It can be concluded that the addition of (15 and 60 ppm) concentrations of silver nitrate can improve impact strength of autopolymerizing acrylic resin.