EVALUATION OF A NEWLY FORMULATED AUTOPOLYMERIZED ACRYLIC RESIN PERMANENT DENTURE BASE MATERIAL (In Vitro Study)

Abstract

INTRODUCTION: Auto-polymerizing acrylic resin with pour technique provides an alternative method to conventional compressionmolding processing for denture base resin. This technique offered improved adaptation, dimensional stability, reduced cost and simplicity of procedure. OBJECTIVES: To investigate some of the physico-mechanical properties of a newly formulated auto-polymerized pour resin permanent denture base material and compare them with conventional heat cured resin. MATERIALS AND METHODS: The study was conducted on two parallel groups according to the denture base material used Group (I) conventional heat cured resin (control group), Group (II) newly formulated auto-polymerized pour resin (study group) of 35 specimens each (14 for impact strength test, 14 for flexural strength test, 7 for warpage test and grinded powder from the cured material for estimation of residual monomer test). Will be examined in this in vitro study. Each group was divided into 2 subgroups: (A) Zero-thermo-cycling (no thermocycling) and (B) Thermo-cycling, then subjected to 4 different tests, impact strength, flexural strength, warpage and quantitative analysis for estimation of residual monomer test. All data from both groups in this in-vitro study was gathered, tabulated and statistically analyzed. RESULTS: The results showed that denture bases processed from auto-polymerized pour resin exhibit high adaptation (low warpage) comparable to those heat cured, and this adaptation significantly increased after thermo-cycling, on other hand, results revealed significantly high amounts of residual monomer of pour resin in both condition (before & after thermo-cycling) in comparison with heat cured resin with significant reduction in these levels after thermo-cycling for both materials. While the impact strength of pour resin was significantly lower than heat cured with no significant increase of flexural strength. CONCLUSIONS: Auto-polymerized pour resin exhibit high adaptation accuracy which is related to the investing medium & technique of processing. On the other hand, containing high amount of residual monomer affecting the physico-mechanical properties. Generally, thermalcycling improve the mechanical and bio-compatibility of the material.