Compressive Strenght of Dental Stone with Incorporation of Disinfecting Solutions

Objectives: The objective of this study was to evaluate the compressive strength of a type IV dental stone (Vel Mix) manipulated with two disinfecting substances (2 % glutharaldeyde and 1% sodium hipochlorite) in different ratios. Methods: The specimens were obtained from bipartite cylindrical matrices (20mm/diameter x 40mm/height), fixed on a glass plate. Dental stone was manipulated in the ratio water-powder recommended by the manufacturer, in a mechanical mixer and gently vibrated into the cylinder. Six groups were confectioned (n=15): C (control - distilled water), G25 (substitution of 25% of the water for glutharaldeyde), G50 (substitution of 50% of the water for glutharaldeyde), G100 (total substitution of water for glutharaldeyde), H25 (substitution of 25% of the water for hipochlorite), H50 (substitution of 50% of the water for hipochlorite). The specimens were submitted to the compression assay, after 24 hours, in a MTS-810 machine (speed=0.5mm/minute). The average values of compressive strength (MPa) were submitted to the variance analysis (ANOVA) and Tukey test (p=0.05). Results: The C group (32.00) and G25 (32.57) showed statically higher values than the group H25 (22.72). The other groups (G50 – 28.62, G100 – 28.09 and H50 – 28.60) showed no significant statistic differences in relation to groups C, G25 and H25. Conclusion: It was observed that only the specimens manipulated with 25% of sodium hipochlorite presented lower compressive strength values than the Control group.