Effect of low-level laser therapy as an adjuvant in the treatment of periodontitis induced in rats subjected to 5-fluorouracil chemotherapy

Background and Objective: This study aimed to assess the effect of multiple sessions of a low-level laser therapy (LLLT) adjuvant to scaling and root planing (SRP) on the treatment of experimental periodontitis (EP) in rats treated with 5-fluorouracil (5-FU). Material and Methods: A total of 120 rats were divided into five groups: no treatment (NT); treatment with 5-FU (60 and 40 mg/kg) and no local periodontal treatment (5FU); treatment with 5-FU and SRP (5FU-SRP); treatment with 5-FU, SRP and one LLLT session (660 nm; 0.035 W; 4.2 J; 120 s) (5FU-SRP-1LLLT); and treatment with 5-FU, SRP and four LLLT sessions (0, 24, 48 and 72 h) (5FU-SRP-4LLLT). EP was induced in the mandibular molars through ligature placement. The alveolar bone loss (ABL) area in the furcation region was analysed histometrically. TRAP, proliferating cell nuclear antigen, RANKL, osteoprotegerin and activated caspase-3 patterns were analysed by immunolabeling. Prostaglandin E2 was quantified using an ELISA, and tumour necrosis factor a and interleukin-6 were assessed using the multiplex method. The prevalence rates of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella nigrescens, Prevotella intermedia and Fusobacterium nucleatum were assessed using the PCR method. The data were subjected to statistical analysis (alpha = 5%). Results: 5FU, 5FU-SRP and 5FU-SRP-1LLLT treatment groups showed higher ABL compared with the NT group (p < 0.05), whereas the 5FU-SRP-4LLLT group showed lower ABL compared with the 5FU group on day 7 and decreased RANKL immunolabeling (p < 0.05). Conclusion: Treatment with 5-FU worsened EP, and multiple LLLT sessions adjuvant to SRP seemed to improve periodontitis in rats subjected to 5-FU chemotherapy. (AU)