Effects of Different Doses of Systemic UVB 310nm Irradiation in Gingivitis Rat Model

Gingivitis is one of the most common periodontal diseases that affects people worldwide. The primary treatment for gingivitis is scaling and root planing. However, despite this therapy, the problem may still recur. New strategies for treating periodontal diseases aim to maintain the natural oral microbiota while modifying the host immune response.The ultraviolet B (UVB) influences the innate and adaptive immune system. This study aimed to determine the effects of different doses of systemic ultraviolet B radiation at 310 nm in the gingiva using gingivitis rat model by observing the number of lymphocytes, macrophages, new blood vessels, fibroblasts, and interleukin (IL)-4 expression. In this study, twenty-five gingivitis Wistar rats were divided into five groups consisting of control group P0 (without UVB irradiation), and irradiation groups P1, P2, P3, and P4 (with UVB irradiation of 12.5, 25, 50, 100mJ/cm2 respectively) every day for ten days. All groups were sacrificed on day 21st, and then the number of lymphocytes, macrophages, new blood vessels, fibroblasts, and interleukin (IL)-4 expression were compared via Hematoxyline Eosin (HE), and Immunohistochemical (IHC) staining. The statistical results showed that group P2 had the highest number of lymphocytes, new blood vessels, and fibroblasts were significantly different from groups P0, P1, and P4, but not significantly different from P3. P2 also had the highest IL-4 expression, significantly different from P4 and not significantly different from P0, P1, and P3. Group P3 showed the highest number of macrophages, significantly different from groups P0 and P1 but not significantly different from groups P2 and P4. It was concluded that systemic UVB 310 nm irradiation in different doses affects the count of gingiva lymphocytes, macrophages, new blood vessels, fibroblasts, and IL-4 expression in the gingivitis rat model. The number or expression of each variable does not always increase with increasing UVB dose. At the dose of 25 mJ/cm2, almost all parameters were increased and then decreased at the higher dose.