Objective

The main objective was to demonstrate the importance of the relation between time and polymerization temperature (Polymerization Cycle) on the residual monomer concentration of the heat polymerized acrylic resins used in the elaboration of denture bases.

Methods

For quantification and analysis of residual monomer 3 discs of every commercial acrylic resin were made, according to manufacturers' instructions (9 discs). Those were analyzed by Gas Chromatography (GC) for the quantification of the residual monomer concentration. Also, 3 discs of every acrylic resin applying three different polymerization cycles were made: conventional method M1, short-term terminal boiled M2 and long-term terminal boiled M3 (27 discs), to be analyzed by Gas Chromatography for the quantification of the residual monomer concentration.

Results

The analysis showed that the resin Acriethil® MMR was 0.3780%, while the resin Nictone® has the lowest percentage, reaching a value of 0.0482% of MMR and resin-45 High Impact Denture Acrylic® has the highest percentage of residual monomer produces a value of 0.5770%. While analyzing the results from the three different polymerization cycles applied, a significant change from the residual monomer concentration on both acrylic resins analyzed was observed.

Conclusions

The three acrylic denture base resins analyzed in this research fulfill the residual monomer concentration established by ISO 1567:1999 with success to be handled under the manufacturer conditions. But if the polymerization cycle is changed, alterations of the residual monomer concentration will be obtained.