Rheological properties and biocompatibility of endodontic sealers

To determine the flow characteristics and subcutaneous tissue reactions to five endodontic sealers.

The materials used were Procosol, AH26, Endomethasone, Sealapex and Endion. The sealers were prepared following the manufacturers' instructions, and 0.075 mL of each material was placed on a glass surface, which was then rotated 90 degrees. The samples were stored at 37 degrees C and 95% humidity. The displacement of the sealer was recorded by measuring the difference between its original position and the position recorded at 15 and 60 min. Three samples of each material were used. Two pockets were created in the back of Wistar rats, and one silicone tube, 1 mm in diameter and 1 cm in length, was implanted in each. One was filled with one of the materials under study, and the other empty tube was implanted as a control. Fourteen days after implantation, the animals were sacrificed, and samples of the skin containing the tubes were histologically processed. Histological and histomorphometric evaluations of the tissues adjacent to the open end of the tube were carried out the volume of tissue reaction was measured histomorphometrically according to standard stereological principles. Results were statistically analysed using analysis of variance and Duncan's test.

The highest flow values were obtained with Sealapex and AH26. Time significantly affected the flow and the material (P < (1001). Procosol and Endion produced the most severe histological reactions: these were outlined by fibrous tissue; AH26. Endomethasone and Sealapex produced reactions of smaller size and with more moderately defined limits.

The flow did not correlate with the degree of inflammatory response. Procosol and Endion produced the most severe tissue reactions, whereas Endomethasone, Sealapex and AH26 produced only minimum reactions.