Experimental Periodontitis Does Not Influence the Peripheral Nerve Regeneration in Wistar Rats after Axonotmesis

Abstract

Background and Objective: This paper aims at analysing the effect of the inflammatory periodontal disease condition on the peripheric nerve regeneration. Methods: Thirty-two male rats were used and divided in 4 groups: control (CG); periodontitis (PG); nerve injury (IG); periodontitis with nerve injury (IPG). On the first experiment, the animals were submitted to a bilateral ligature around the lower first molars. Then, on the fifteenth day, they were submitted to a peripheral nerve injury and euthanised on the thirtieth day, then, their sciatic nerve and their right hemimandibles were collected. Results: The induction of the periodontitis was proved by the histomorphometric of the mandible. When it comes to the nerve morphometric analysis, there was no difference among the nerve fibers groups (NF) compared to the viable FN longer than 4 micrometers (µm), CG and PG presented higher quantity of IG and IPG, on the less than 4 µm fibers, being similar in these groups. CG and PG presented smaller quantity of nonviable fibers. The NF diameter, axon and myelin sheath, CG and PG presented diameters longer than 4µm, while only the MS presented shorter than 4µm difference, CG presented a longer diameter than IG and IPG. All groups depicted similar quantities of blood vessels, conjunctive tissue and cell nuclei density, CG and PG presented lower values than the other groups. Conclusion: Therefore, it can be suggest that induced periodontitis did not influence the sciatic nerve process of regeneration.