Modification of heat cured acrylic resin by using additives to make a flexible acrylic resin denture base material: A pilot study

Aims: The study was conducted to modify heat cured acrylic resin denture base material with additives [flavoring agents (caramel, banana)], and plasticizer into a flexible heat cured acrylic resin as a Flexite thermoplastic material. Methods: One hundred ninety-five samples of heat cured acrylic resin (HCAR) that consist of control group and three types of additives with two concentrations 15%, and 20% [flavoring agents (caramel, banana)], and plasticizer di-butyl phthalate (DBP) addition to (HCAR) 20% group, plasticizer (DBP) addition to (HCAR) group, flavoring (caramel) addition to (HCAR) group, flavoring (banana) addition to (HCAR) group and flexite thermoplastic material group were prepared to examine tensile strength, water sorption, solubility, color change and dimensional accuracy. Results: Statistically significant differences were identified between groups with and without additives exhibited higher mean value of tensile strength of flexite thermoplastic group. Duncan's multiple range test, and ANOVA were done to evaluate the effect of additives against each additive, concentration and storage time of samples. The result showed that the dimensional accuracy, water sorption and solubility tests of the groups (caramel + plasticizer + heat cured acrylic resin) had statistically lower changes than other groups with additives but were still higher than control group and Flexite thermoplastic during seven days. They also showed color change between groups. The first group (caramel + plasticizer + heat cured acrylic resin) with the concentration of 20% showed lowest change in their properties when compared with the plasticizer group and the other groups of flavors additions (caramel and banana) after seven days and six months. Conclusion: Within the limitation of this research, it was concluded that all prepared samples with additives (caramel, banana, and plasticizer) have better properties than the control group except the Flexite thermoplastic group which showed to have a higher tensile strength than control group during the periods of two and seven days.