Aim: To evaluate the influence of bismuth subsalicylate addition in different concentrations on theproperties ofan experimental epoxy-based root canal sealer. Methods: Bismuth subsalicylate in 20%, 40%, 60%, 80%, 100% and 120 wt% was added tothe sealer. Flow, film thickness, working time, setting time, dimensional change, sorption, solubility and cytotoxicity were evaluated according to ISO standard. Data were statistically analyzed by one-way ANOVA and Tukey'stest with a significance level of 5% for all tests. Results: The flow, working and setting times significantly decreased withincreasing particle concentration. The film thickness, dimensional change, water sorption and solubility values significantly increased with higher particle amount. The results for cytotoxicity showed no statistically significant differences among the particle proportions. Conclusions: The results suggest that the addition up to 80% wt of bismuth subsalicylate appears to be a promising filler particle to root canal sealer development.

Introduction: The aim of this study was to evaluate the addition of bismuth subcarbonate with different concentrations regarding the rheological properties of an experimental epoxy-based root canal sealer. Materials and Methods: Endodontic sealers were prepared with epoxy resin-based sealer with bismuth subcarbonate additions of 20%, 40%, 60%, 80%, 100%, and 120%. Flow, film thickness, working time, setting time, dimensional change, sorption, solubility, and cytotoxicity were studied according to the ISO standards. Data were statistically analyzed by one-way ANOVA, and Tukey multiple comparisons were used, with a significance level of 5%. Results: The flow, working time, water sorption, and solubility significantly decreased and the film thickness and dimensional change increased with higher filler particle addition. There were no statistically significant differences for setting time and cytotoxicity between the filler particle proportions. Conclusion: Experimental resin-based sealer with bismuth subcarbonate addition up to 40% can be an alternative for root canal sealer.

The aim of present study was to evaluate the wear coeficient of different dental materials submited to ballcrattering test. Different restorative materials were compared to bovine enamel. The samples were made with nylon matrix stripes and had 7mm diameter and 2mm thickness. The samples were submitted to the ballcratering test in a Calowear tribometer (CSEM Instruments Advanced Mechanical Surface Testing) and maded six measures in each sample with different revolutions of the ball: 10, 20, 30, 40, 50 and 60 revolutions. After the crattering generation the samples were avaliated to a Zeiss Axiotech Vario Microscope with SVGA Cam and all cratters photographed. After, the photos were evaluated at UTHSCSA ImageTool for Windows 3.0 and the meaning of measured radius were inserted at SigmaPlot, that gave the wear coefficients by linear regression. To bovine enamel the coefficient was 3,83 X 10-14 m²/N, to microhybrid resin was 3,6542 x 10-14 m²/N, 2,06 x 10 -12 m²/N to amalgam and 2,18 x 10 -12 m²/N to acrylic resin. In conclusion, bovine teeth presented higher wear resistance and lower wear coefficient than composite resin, amalgam and acrylic resin.