Evaluation of the flexural strength and Color Stability of two injection acrylic resins and a heat-cure acrylic resin

An important consideration in newly introduced acrylic resins is to determine the flexural strength and color stability of dentures fabricated using these materials. The general aim of this study was to evaluate and compare the flexural strength and color stability of two injectable acrylic resins (IvoBase High-Impact and Vertex Castavaria) and a heat-cured acrylic resin (Meliodent). In this study, 30 cuboid samples were fabricated (10 specimens from each group), measuring 3 mm in thickness and 67×15 mm in dimension. The flexural strengths of the samples were determined using 3-point flexural strength test and their color changes were evaluated by immersion in tea using spectrophotometry technique. Data were analyzed with SPSS 22, using one-way ANOVA and HSD Tukey tests (α = 0.05). The mean flexural strength values of the IvoBase, Vertex Castavaria and Meliodent samples were 58.16, 66.01 and 77.38 MPa, respectively. In relation to color changes, the ΔE values of IvoBase, Vertex Castavaria and Meliodent samples were 6.56, 3.59 and 6.23, respectively. Meliodent heat-cured acrylic resin which uses the conventional system showed the best flexural strength, and Vertex Castavaria showed the best color stability.