The Influence of the Thickness of the Materials for the Provisionalization in Minimally Invasive Restorations

This in vitro study aimed to determine the flexural strength and modulus of elasticity of two bisacrylic resins for temporary crowns at different thicknesses, i.e., Structur 3 and Structur Premium, and to compare them with each other. Sixty samples were prepared, thirty of each material, which were made at different thicknesses (1 mm, 1.5 mm, and 2 mm). The dimensions followed the UNE-EN ISO 178:2019 standard, with a length of 24 mm, a width of 10 mm, and the thicknesses described. Materials were subjected to a three-point bending test. For the modulus of elasticity, statistically significant differences were observed between the 1.5 mm and 2 mm thicknesses of Structur 3 material. For Structur Premium, statistically significant differences were observed between the thicknesses 1 mm and 1.5 mm as well as between 1 mm and 2 mm thickness. With respect to flexural strength, no statistically significant differences were observed for either material at the different thicknesses. Significant differences were observed between the materials for both flexural strength and modulus of elasticity, being higher for Structur Premium: Structur Premium has a higher flexural strength and modulus of elasticity than Structur 3. There are significant differences for the modulus of elasticity but not for the flexural strength between thicknesses.