Effects of low-level laser therapy on the bone healing process in rats under the influence of chronic alcohol intake

Abstract

Chronic alcohol consumption is associated with prolonged hospital stays, high number of referrals to intensive care units and harm in the tissue repair process. Excessive chronic alcohol consumption decreases bone formation through a direct toxic effect on the function of osteoblasts, besides changing the signaling pathways related to the inflammatory response. Thus, it is necessary to investigate the treatments wich present an osteogenic potential and are able to accelerate the process of bone repair in alcoholics. The Low-level laser therapy (LLLT) is a widely used resource for accelerating bone metabolism. There are evidence that LLLT can stimulate bone cells and accelerate the repair process, but there are no studies that support the implementation of this promising therapeutic intervention in the bone tissue of experimental models on chronic alcohol intake. The objective of this study is to analyze the effects of LLLT in the process of bone repair in rats undergoing chronic excessive alcohol intake. For this purpose, 30 adult male Wistar rats will be divided into three groups: control (n = 10), alcohol (n = 10) and alcohol + LLLT (n = 10). Each group will be divided into two groups of 5 animals each, for analysis 7 days post-lesion (n = 15) and another 14 days post-lesion (n = 15). Alcohol administration will be held by the two bottles protocol with access to a water bottle and other alcohol bottle, containing solution 20%, 3 days a week for 45 days. The bone defects with diameter of 3 mm will induced by a dental trephine drill type on animal's tibia and the treatment with LLLT starts immediately after the injury. It will be performed histological cross sections for qualitative analysis of inflammation, granulation tissue, necrotic area, tissue structure, morphometric analysis and immunohistochemical analysis of the RANKL and RUNX2 expression.