Biocompatibility of resin composites subcutaneously implanted in rats with experimentally induced arthritis.

Objective: To evaluate the biocompatibility of resin composite specimens with different curing efficiency, subcutaneously implanted in rats with experimentally induced arthritis.

Methods: The amount of remaining CC bonds (%RDB) of hybrid resin composite specimens photopolymerized for 10s and 40s exposure time (n=3) was measured by micro-attenuated total reflectance Fourier transform infrared spectroscopy. Male Wistar rats (n=36) were classified in two groups (n=18) of healthy animals and of animals with experimentally induced arthritis. Resin composite specimens irradiated for 10s and 40s and calcium hydroxide control specimens were implanted subcutaneously in each animals' dorsum. Following 2-, 4- and 9-week periods the animals were sacrificed. The development of arthritis was defined by biochemical analysis and the changes in the relative weight of animals' organs (spleen, thymus, adrenals). Tissue reactions were examined histologically.

Results: %RDB per site and exposure time showed statistically significant differences. Lowest %RDB values were recorded on 40s exposed specimens. Biochemical indices and relative organ weights demonstrated statistically significant differences between healthy animals and animals with arthritis. The health status of the animals and the materials used did not influence tissue response. First and second periods of sacrifice showed reduced propensity of connective tissue development in comparison to the third period. The same applied for the second period regarding the presence of giant cells.

Significance: The materials tested and the animals' health status did not result in altered tissue response compared to control group. The period of sacrifice was associated with different tissue responses.