Evaluation of different protocols of antimicrobial photodynamic therapy (aPDT) in the treatment of the induced periodontitis in rats treated with chemotherapy: a histomorphometric, immunohistochemical and immunologic study

Abstract

Objective: This study aims to evaluate the immune-inflammatory response in periodontal tissue with experimental induced periodontitis in rats immunosuppressed with chemotherapy and treated with: conventional mechanical therapy; different protocols for the application of low intensity laser therapy associated with mechanical therapy; application of different protocols of antimicrobial photodynamic therapy (aPDT), with or without the mechanical treatment. Method: Periodontitis will be induced by placing a ligature around the mandibular molar in 216 rats. The animals will be divided into 9 groups: Group I (n = 24) - represented by animals that do not suffer any systemic or local treatment and Group II (n = 24) - treated animals systemically with 5-fluorouracil (5-FLU), without local treatment; Group III (n = 24) - animals treated systemically with 5-FLU and treated with scaling and root planing (SRP); Group IV (n=24) animals treated systemically with 5-FLU, treated with scaling and root planing (SRP) followed by treatment with low level laser therapy (single application); Group V ( n=24) - animals treated systemically with 5-FLU, treated with scaling and root planing (SRP) followed by treatment with low level laser therapy (0, 24, 48, 72 hours); Group VI (n = 24) - animals treated systemically with 5-FLU, treated with scaling and root planing (SRP) followed by treatment with aPDT (single application); Group VII (n = 24) - animals treated systemically with 5-FLU and treated with SRP followed by treatment with aPDT (0, 24, 48, 72 hours); Group VIII (n = 24) - animals treated systemically with 5-FLU followed by treatment with aPDT (single application); Group IX (n = 24) - animals treated systemically with 5-FLU and treated with aPDT (0, 24, 48, 72 hours). The chemotherapeutic agent 5-FLU will be applied when installing ligature and 48 hours after its installation in groups II, III, IV, V, VI, VII, VIII and IX. Local treatments will be performed 7 days after induction of periodontitis. Animals, numbering eight in each group will be euthanized at intervals of 7, 15 and 30 days after local treatment. Specimens will be processed to make the histopathological, morphometric, immunohistochemical, immunological and microbiological analysis. The results will be analyzed with the statistical analysis significance level of 5%. (AU)