Detection of Mmp-8 expression in nanosilver-treated and tetracycline-treated periodontitis induced in albino rats

Objective: This study aimed to evaluate the histopathological expression of Mmp-8 in the experimentally-induced periodontitis treated with tetracycline, and nanosilver in albino rats.
Material and Methods: fifty five male albino rats were included in this study. On the first day, 5 rats were euthanized as healthy group for histological characteristics of interdental alveolar bone between the maxillary incisors. Fifty rats were anesthetized; elastic rings were placed around the cervix of the right maxillary incisors for 7 days to induce periodontitis. On the eighth day, the ligatures were removed, five rats were euthanized before any treatment (day zero) and served as positive control group. The remaining 45 rats were randomly assigned to three groups as following: Group I; 15 rats did not receive any treatment. Group II; 15 rats treated locally with tetracycline hydrochloride (50 mg /mL) daily. Group III; 15 rats treated locally with nanosilver (12.5μg /mL) daily. Five animals from each group (I, II and III) were euthanized at day 7, 15 and 30 of day zero. The area of the maxillary incisors was decalcified and processed for hematoxylin and eosin stain and immunohistochemical stain for Mmp-8.
Results: Local application of nanosilver in experimentally-induced periodontitis in rats exhibited tendency for bone formation from day 7 with externalization of the inflammation compared to local application of tetracycline. The tetracycline treatment demonstrated tendency for localization of inflammation detected as abscess formation. The tendency for new bone formation was detected after 15 days of treatment. Mmp-8 expression was strongly expressed after the induction of periodontitis. In nanosilver treated group, Mmp-8 started to fade within the connective tissue from day 15 and was detected only on the surface epithelium. In tetracycline group, Mmp-8 was detected at day 15 surrounding the abscesses then it completely disappeared at day 30.
Conclusion: Mmp-8 is intensely expressed in inflamed periodontal tissue. This expression fades earlier with the nanosilver treatment compared to the tetracycline treatment. The non-inflamed periodontal tissues did not express Mmp-8.