Using of HPLC Analysis for Evaluation of Residual Monomer Content in Denture Base Material and Their Effect on Mechanical Properties

The samples were prepared according to the routine work for sample preparation in dental laboratories. After reaching dough stage, the mixture packed into dumbbell shaped of stainless steel mould and pressed in a hydraulic bench press for 25 min at room temperature. For heat-cure, the polymerization cycle was carried out using water bath, while self-cure done at room temperature. The residual monomer content was evaluated using high performance liquid chromatography (HPLC). The tensile test was evaluated in dry and wet condition (distilled water). The results showed that the residual monomer content for heat-cure samples was 1.44 wt. % while self-cure samples was 8.71 wt. %. The residual monomer content of heat-cure samples was comply with ISO-1567 standard for denture base material. The heat-cure material depicted higher tensile strength, tensile strain and energy at break than that of self-cure material. This is due to higher residual monomer content in self-cure which acts as plasticizer, subsequently lead to reduce the properties of self-cure material. After immersion, the tensile strength, tensile strain and energy at break of heat-cure samples found to decrease, while the self-cure samples were found to increase. Generally, the heat-cure material showed better properties compared to self-cure material.