Compressive strength of glass ionomer and composite resin. In vitro study

Objective: To assess compressive strength of glass ionomer and composite resin restorations in premolar class I cavities. Material and methods: In vitro experimental study to assess compressive strength of two types of stomatological restoration materials, using as object of study 52 bi-radicular premolars. Samples were distributed into four groups with different characteristics such as restorative material and cavity depth (2-4 mm). Glass ionomer and composite resins were the used restorative materials. Grouped samples were subjected to a compressive vertical force using a EZ-S SHIMADZU texturometer, until achieving the material’s fracture. Obtained data were subjected to the Shapiro-Wilk test in order to assess data normalcy, null hypothesis was rejected. Total data analysis was conducted with t-Student test for independent samples. Results: Data obtained after assessing superficial hardness of different restorative materials showed the existence of statistical differences which favored composite resin when compared to glass ionomer at both depths (p = 6.908 × 10-11 and p =0.000). In intra-group comparison, a signifi cant different was found between both groups (resin and glass ionomer) at different depths (p = 0.000155887 and p = 0.00257443). Conclusion: Assessment of 4 mm tooth cavities restored with Tetric N-Ceram resin revealed greater hardness than those accomplished with Vitremer® resin at 2 and 4 mm and with the same resin at 2 mm depth.