Abstract
AIMS: Evaluation of the impact strength of maxillary complete dentures fabricated from new type high impact heat-cured acrylic denture base material and comparison with other types of acrylic resin denture base materials. MATERIALS AND METHODS: Three types of materials were used in this study, high impact heat-cured acrylic resin; cross-linked acrylic resin (no cadmium); and conventional heat-cured acrylic resin. Twenty four maxillary complete dentures were fabricated to be tested and divided into three groups. Group 1, Group 2, and Group3 for high impact acrylic resin, cross-linked acrylic resin, and conventional heat- cured resin, respectively. Before testing, all specimens were stored in distilled water at 37ºC for 2 months. The impact strengths (J) of the dentures were measured with a falling-weight impact test. The impact strengths of both groups were compared by a repeated measures analysis of variance (ANOVA) and Duncan's Multiple Analysis Range Test to determine the signifi-cant difference among the tested groups at (p<0.001) level of significance. RESULTS: There is a sig-nificant difference of the mean values of impact strengths for high impact acrylic resin, cross linked acrylic resin and conventional acrylic resin denture base materials at crack initiation and complete frac-ture. The impact strength between crack initiation and complete fracture within each group was signifi-cantly different (p<0.001) for all the groups, and more energy was needed for complete fracture than that for crack initiation for the high impact strength acrylic resin. CONCLUSIONS: Maxillary com-plete dentures made from high impact acrylic resin denture base material have significantly higher im-pact strength than that of maxillary complete denture made from cross-linked and conventional acrylic resin denture base materials. Maxillary complete dentures made from cross-linked acrylic resin denture base material have significantly higher impact strength than that made from conventional acrylic resin denture base materials.
