Subcutaneous reactions to implantation of tubes with AH26 and Grossman's sealer.

Twenty-seven polyethylene tubes filled with either U of P brand of Grossman's sealer or silver-free AH26 (Dentinol) were implanted in the backs of seven young guinea pigs. Tissue reactions were studied histologically after 2 months and graded for inflammation and thickness of capsule. The surface of AH26 that was slightly convex or flush with the opening of the tube had a significantly thinner capsule than U of P. The latter also caused more inflammation. The more severe subcutaneous tissue reaction to the zinc oxide--eugenol type of sealer was probably due to the instability of the material, which slowly disintegrated in contact with tissue moisture. This process continuously liberated new foreign particles and prevented resolution of inflammation.