Comparative Evaluation of the Compressive Strength of a Direct Composite Resin and Two Laboratorial Resins

Purpose: To compare the compressive strength of two commercially available laboratorial resins - Solidex (Shofu) and Cristobal (Dentsply) - to that of a direct composite resin (Concept ; Vigodent), as a control group.Method: Five specimens of each tested material were fabricated using stainless steel matrices with the following dimensions: 8 mm of internal diameter on the base, 9 mm of internal diameter on the top and 4 mm of height. The specimens were stored in distilled water for 72 hours and submitted to an axial load by the action of a 2-mm-diameter round-end tip adapted to a universal testing machine (EMIC 500). A 200 kgf load cell was used running at a crosshead speed of 0.5 mm/min. The load and the point of failure were recorded. Results: Means, in kgf, were: Concept (Ct) = 124.26; Cristobal (C) =184.63; Solidex (S) =173.58. Data (means and standard deviations) were analyzed statistically by ANOVA and Tukey’s for comparisons among the groups using the SPSS software (version 10.0). Significance level was set at á=0.05 (95%). Concept presented significantly lower (p<0.05) compressive strength than the other two materials, Cristobal and Solidex , which, in turn, did not differ significantly to each other.Conclusion: Cristobal and Solidex laboratorial resins did not show significant difference to each other and both presented compressive strength significantly higher than that of Concept direct resin.