Hypericin-glucamine antimicrobial photodynamic therapy in the progression of experimentally induced periodontal disease in rats

Abstract

Objective: To evaluate the effect of antimicrobial photodynamic therapy (aPDT) using the photosensitizer hypericin-glucamine in the progression of experimentally induced periodontal disease (PD) in rats. Material and methods: Subgingival ligatures were inserted around the upper second molars of 30 rats. After 7 days (Baseline), the animals were randomly distributed into 3 experimental (n = 5) groups: Hypericin-glucamine; LED (amber LED, 700 mA, 590 nm, 90 mW, 34.10 J/cm 2 ); and aPDT (Hypericin-glucamine + LED). The treated hemimaxillae were randomly chosen. The periodontal disease progression was monitored without treatment interference in the opposite hemimaxillaes, which were used as the negative control of each animal. The euthanasia was programmed according to each experimental period, 7 or 15 days after the Baseline. Microtomographic, histometric and Tartrate Resistant Acid Phosphatase (TRAP) immunohistochemistry analyses were carried out. Results: Computerized microtomography analyses indicated that the aPDT group had a significantly higher percentage of bone tissue when compared to the other 7 days experimental groups. This result was corroborated by the histometric evaluations of the furcal area. The LED-treated group presented the highest percentages of bone volume for the 15 days experimental groups, which is remarkably higher than the groups treated with Hy-g and aPDT. The histometric analyses demonstrated the control groups had greater bone loss in the proximal regions when compared to the treated groups. The aPDT led to a lower osteoclast activity at both 7 and 15 days. Thus, we can conclude that aPDT exhibits positive effects in PD treatment by promoting favorable conditions for periodontal repair.