Biocompatibility of intracanal medications based on calcium hydroxide

Abstract

Objective. The aim of this study was to evaluate the rat subcutaneous tissue reaction to calcium hydroxide-based intracanal medicaments, UltraCal XS (calcium hydroxide, barium sulphate, aqueous matrix), Hydropast (calcium hydroxide, barium sulphate, and propyleneglycol), and Calen (Calcium hydroxide, zinc oxide, colophony, and polyethyleneglycol), used as a control. Methods. Forty-eight rats (Rattus Norvegicus Holtzman) were distributed in three groups: Calen, UltraCal XS, and Hydropast. Polyethylene tubes filled with one of the medicaments were implanted in the dorsal subcutaneous. After 7 and 30 days, the implants were removed and the specimens were fixed and embedded in paraffin. Morphological and quantitative analyses were carried out in the HE-stained sections. The numerical density of inflammatory cells in the capsule was evaluated and statistical analyses were performed (P ≤ 0.05). Results. At 7 days, all materials induced an inflammatory reaction in the subcutaneous tissue adjacent to the implants. In all groups, a significant reduction in the number of inflammatory cells and giant cells was verified in the period of 30 days. Conclusion. These results indicate that the calcium hydroxide-based medicaments evaluated present biocompatibility similar to Calen.

Figure 1

Light micrographs of sections showing portions of capsules adjacent to the opening of the tubes (I) filled with Calen paste after 7 (a) and 30 days (b and c) of implantation in the subcutaneous. In (a), numerous inflammatory cells (ICs) are observed in the inner portion of the capsule adjacent to the tube opening (I). The inset of the outlined area shows multinucleated giant cells (GCs) in close juxtaposition to the material implanted. BV, blood vessels. ×110; inset: ×250 (b) shows the capsule exhibits several fibroblasts (Fb) dispersed among the collagen fiber bundles (CF) ×130. In (c), outlined area in (b), shows some inflammatory cells (arrows), mainly lymphocytes, situated adjacent to the blood vessels (BV) ×250.

Figure 2

Light micrographs of sections showing portions of capsules adjacent to the opening of the tubes (I) filled with UltraCal XS paste after 7 (a) and 30 days (b) of implantation in the subcutaneous. In (a), The capsule exhibits several inflammatory cells (IC) and blood vessels (BV). Note that dense masses of inflammatory cells (ICs) are observed in the inner portion of the capsule, adjacent to the tube opening (I). The inset, outlined area, shows multinucleated giant cells (GCs). ×120; inset: ×230. (b) The capsule contains several fibroblasts (Fbs) and numerous blood vessels (BV). Inflammatory cells (arrows), lymphocytes and macrophages are situated mainly in the inner portion of the capsule and next to the blood vessels ×150.

Figure 3

Light micrographs of sections showing portions of capsules adjacent to the opening of the tubes (I) filled with Hydropast after 7 (a) and 30 days (b) of implantation in the subcutaneous. In (a), numerous inflammatory cells (ICs) and multinucleated giant cells (GCs) are present by thorough capsule. BVs, blood vessels ×120. (b) The capsule contains predominantly inflammatory cells (arrows); scarce collagen fibers (FC) distributed irregularly are observed in the capsule. BVs, blood vessels ×120.