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 compression-molding 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 thermo-cycling) 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, thermal-cycling improve the mechanical and bio-compatibility of the material.