Determining the Dimensional Stability, Fracture Toughness and Flexural Strength of Light-cured Acrylic Resin Custom Tray Material

Abstract - Light-cured acrylic resin custom tray material is used in commercial dental laboratories but little evi-dence-based scientific information on its physical properties is available. Objectives: This study investigates the dimensional stability of light-cured acrylic resin custom tray material and compares its fracture toughness and flexural strength to a chemically-cured acrylic material. Method: For dimensional stability, 20 light-cured specimens were fabricated and measured 3 times at regular time intervals over 48 hours. Mean shrinkage was calculated for each time interval and the mean values were compared to the standard using the Wilcoxon Rank Sum test. A p-value of 0.05). The fracture toughness and flexural strength were significantly higher for the light-cured material. Conclusions: Trays made from light-cured acrylic resin can be used immediately following polymeriza-tion. The light-cured material is more resistant to bending and crack propagation than the chemically-cured type. KEY WORDS: Custom tray; polymethyl methacrylate resin; chemically-cured; light-cured; dimensional stability; fracture toughness; flexural strength.