Sebastian Balos,  Tatjana Balos, Leposava Sidjanin, Dubravka Markovic, Branka Pilic, Jelena Pavlicevic Flexural and Impact Strength of Microwave Treated Autopolymerized Poly(Methyl Methacrylate)

Sebastian Balos, Tatjana Balos, Leposava Sidjanin, Dubravka Markovic, Branka Pilic, Jelena Pavlicevic Flexural and Impact Strength of Microwave Treated Autopolymerized Poly(Methyl Methacrylate)

Abstract:
The aim of this study was to optimize microwave post-polymerization treatment parameters, power and irradiation time, in order to achieve the maximum applicable flexural and impact strength of autopolimerizing poly(methyl-methacrylate) denture reline resins. Specimens were produced from two types of commercial materials. Control group was left untreated, while the other twelve were post-irradiated in a microwave oven with different power and time settings: 500, 550, 600 and 650 W; and 3, 4 and 5 minutes. The amount of residual monomer was determined using DSC and FTIR. Furthermore, visual control has been conducted, in order to check if there any surface changes have appeared. Microwave post-irradiation resulted in increase of all tested mechanical properties, for all specimens. The highest mechanical properties were obtained with maximum irradiation power, which was confirmed by the results of ANOVA statistical analysis. It has been found that residual monomer content strongly influences the benefits in all tested mechanical properties, increasing biocompatibility. The fracture mode of all specimens in untreated and treated conditions was found to be mostly brittle. However, the highest power (650 W) and the longest irradiation time (5 min) resulted in unacceptable surface color and roughness modifications. Keywords: biopolymers, microwave post - polymerization, mechancal properties, residual monomer

Issue: 2009 Volume 46, Issue 3

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