The reaction of rat connective tissue to polyethylene tube implants filled with Hydron or gutta-percha

A subcutaneous tube implant study was conducted on adult Sprague-Dawley rats. Polyethylene tubes sealed at one end were filled flush to the open end with Hydron or gutta-percha and sealer. These implants were immediately placed into dorsal subcutaneous connective tissue for periods ranging from three weeks to 6 months. Tubes filled with Hydron demonstrated expansion and resorption of material with its distribution into connective tissue. A moderately thick connective tissue capsule containing macrophages formed at the tissue-Hydron interface. Amorphous calcific deposits were localized within Hydron, being most dense at the Hydron--tissue interface. Tubes filled with gutta-percha and sealer demonstrated thinner connective tissue capsule formation, with little or no distribution or resorption of material. A mild lymphocyte response was noted within the capsule adjacent to the gutta-percha.