The aim of this study was to evaluate the solubility of gutta-percha in four organic solvents used in endodontics. The solubility of gutta-percha (Dentsply) was assessed in xylol, orange oil, eucalyptol, chloroform and distilled water. A hundred and fifty samples of gutta-percha were prepared using a standardized stainless steel mould and divided into five groups for immersion in the different solvents tested and in distilled water (control group) for 2, 5 and 10 minutes. The means of gutta-percha dissolution in the solvents were obtained by the difference between the pre-immersion original weight and the post-immersion weight in a digital analytical scale (Gehaka - AG2000). Data were statistically analyzed by Analysis of Variance (ANOVA) and multiple comparisons with Scheffe’s test (p < 0.05). The best solvency capacity was obtained with xylol. Chloroform, orange oil and eucalyptol presented similar results, and distilled water did not promote alterations in the gutta-percha.

The purpose of this investigation was to evaluate the microhardness of two laboratory-processed composites (Artglass; belleGlass) and two direct placement composites (Filtek Z250; Alert), after aging in distilled water. Twenty cylinders (8 mm diameter; 2 mm height) per tested material were prepared and stored in 10 ml of distilled water. Five Knoop hardness measurements were made on the surface of the specimens with a Miniload Hardness Tester under a load of 50 g for 30 s at 10 min, 24 h, 30 and 90 days. Statistical analysis was perfomed using two-way ANOVA, followed by a SNK multiple comparison test (p < 0.05). The analysis showed statistically significant difference among hardness means recorded at the different aging time and the tested materials. It may be concluded that all materials presented hydrolytic degradation due to aging in aqueous environment.