Fracture resistance of various temporary crown materials.

AIM The aim of this study was to evaluate the fracture resistance of various provisional crown materials using an in vitro model test system. METHODS AND MATERIALS In the present study polycarbonate crowns, prefabricated by the manufacturer (3M Polycarbonate Crown), and the temporary crowns, fabricated in the dental laboratory environment, were fabricated using bis-acryl composite (Protemp II), autopolymerizing PMMA resin (BISICO Temp S), and heat-polymerized PMMA resin (Major C&B-V Dentine). All temporary crowns were stored in distilled water for 24 hours at room temperature prior to testing. The crowns were seated on metal dies, fabricated from Cr-Co alloy (AZ Dental, Konstanz, Germany), and then tested using the indenter of a Hounsfield testing machine (Hounsfield Tensometer, Hounsfield Test Equipment, Raydon, England). The tip of the indenter was located at a position one-third of the way down the inciso-palatine surface at 135 masculine. The data were statistically analyzed for differences using one-way analysis of variance (ANOVA) and the Tukey HSD test (P < .05). Additionally, the types of failure obtained from the fracture load test were examined using 10x magnification with a stereo microscope. RESULTS The results of the present study indicated polycarbonate crowns were significantly different from the BISICO Temp S, Protemp II, and Major C&B-V Dentine (P < .05) groups. CONCLUSION This in vitro study shows polycarbonate crowns may be preferable to the other types of temporary crowns used in this study.