The effect of the poly vinyl pyrrolidone (PVP) addition on surface hardness and impact strength properties of heatcured acrylic resin denture base material

Abstract

ABSTRACT
Background: Acrylic resin has been used successfully for almost 55 years in prosthetic dentistry. Although widely used
as denture base material, acrylic resin exhibits certain poor mechanical properties induce fracture. The hardness and
impact strength properties of the experimental and heat cured acrylic denture base material were done.
Materials and methods: Twenty specimens, 10 specimens for each experimental or control material were tested.
The biological properties of the prepared material were evaluated in comparison with the control denture base
acrylic resin. Group 1: poly (methyl methacrylate) + methyl methacrylate as control. Group 2: poly (methyl
methacrylate) 80% and poly vinyl pyrrolidone 20% + methyl methacrylate as experimental. The hardness and impact
strength properties of the experimental and heat cured acrylic denture base material were done.
Results: Evaluation of the hardness value for experimental material record number 171.22, while specimens of the
control material showed hardness value record number 112.80. The mean impact strength value of the experimental
material was 19.620 N/mm2 which are higher than that of the control material which is 14.604 N/mm2.
Conclusion: The higher hardness value for experimental group is due to the incorporation of PVP which may increase
stiffness. The impact strength of the experimental group is significantly higher than that of the control group.
Key words: Poly vinyl pyrrolidone, acrylic, hardness, impact strength. (J Bagh Coll Dentistry 2009; 21(4):1-5)