Degree of conversion in denture base materials for varied polymerization techniques 1

Abstract

New processing techniques for denture base acrylic resins have been introduced which have not comparatively quantified the residual monomer content. While proper processing keeps the residual monomer in a tolerable range for most patients, tissue irritation and reaction due to potentially higher residual monomer in these alternative techniques could be a clinical concern. Decreased degree of conversion may influence physical properties as well as biocompatibility. This investigation evaluated the residual monomer content of acrylic resins cured by three different polymerization modes. Materials (polymerization system) evaluated were: Lucitone 199 (conventional process), Accelar 20 (rapid boil-out), and Acron MC (microwave). Fourier transform infrared spectrometry (FTIR) was employed to determine the degree of conversion. All curing methods produced similar results (Lucitone 199 = 92.7% (0.21), Acron MC = 92.6% (0.57), Accelar 20 = 90.9% (0-73). Conversion for Accelar 20 (rapid boil-out technique), though statistically different (P < 0.05, ANOVA) from the other two materials and polymerization techniques, was only slightly less. It is unlikely that the rapid boil-out technique would induce more adverse tissue responses than the other techniques included in this study.

Avaliação de monômero residual em resinas acrílicas de uso ortodôntico e protético: análise por espectroscopia

“…Desde o início de sua utilização até os dias atuais, várias técnicas para o processamento das resinas foram introduzidas com o objetivo de melhoria de suas propriedades físicas, assim como de redução do tempo do processo de polimerização 3 .…”

Surface Hardness of Acrylic Resins Exposed to Toothbrushing, Chemical Disinfection and Thermocycling

“…A traditional study showed that surface hardness values were similar for acrylic resins polymerized by ebullition water and microwave energy (Troung & Thomasz, 1998). In addition, different polymerization methods (Bartolini et al, 2000) and water sorption/solubility levels (Tuna et al, 2008) could be considered significant factors in influencing the surface characteristics of acrylic resins.…”

The Use of Microwave Energy to Polymerize Acrylic Resins

“…7,8 Muflaya alma işlemini takiben mufla mikrodalga fırınında 500-600 W potensiyel ve 3 dakika süre ile mikrodalga enerjisine maruz bırakılır. 6,[9][10][11][12][13][14] Fırındaki döner tabla dalgaların daha fazla ve homojen penetrasyonuna olanak sağlar.…”