Influence of melatonin supplementation on tissue response of endodontic sealers in Wistar rats

Objectives: Evaluate the influence of melatonin supplementation on tissue’s response to endodontic sealers in Wistar rats. Material: and methods: Forty-eight Wistar rats had four polyethylene tubes implanted in their subcutaneous tissue, one empty (control) and three filled with endodontic sealers (AH Plus, Endofill and Sealapex). Half of the animals were supplemented with melatonin (TM) and the remaining with water (TW) for 15 days before the implantation until euthanasia. After 5, 15 and 30 days (n=8/group/period) tubes were removed and analyzed in H&E, immunohistochemistry, PSR, VK and POL. The results were statistically analyzed (p<0.05). Results: : In TW, Endofill evoked a more intense inflammatory infiltrate compared to AH Plus and control in 30-day (p0.05), differences for Endofill (p=0.05) and Sealapex (p<0.05) was observed in TM animals in 30-day, presenting lower inflammatory infiltrate. For IL-6 and TNF-α it was observed that the immunolabeling was lower in TM animals in all periods, despite of the sealer. In addition, there was a higher percentage of mature fibers in TM groups at 5 days (p<0.05). Structures positive for von Kossa staining and birefringent to polarized light were observed only for Sealapex in all periods, regardless of melatonin supplementation. Conclusion: Melatonin influences inflammatory response of endodontic sealers, by modulating the inflammatory process and pre-inflammatory mediators, and stimulating tissue repair, without interfering on calcium deposition. Clinical Relevance: Evidence that melatonin can regulate inflammatory responses after the contact of tissues with biomaterials.