Assessment of LED (λ850 ± 10 nm) phototherapy in the inflammatory process of rat's TMJ induced by carrageenan

摘要

Temporomandibular disorders (TMD) are commonly found in the population and usually involve inflammatory processes. Previous studies have shown positive effects of LED (Light emitting diodes) phototherapies on TMD but its action and mechanism in the inflammatory infiltrate of the temporomandibular joint are still poorly understood. The aim of this study was to assess through histological analysis the effectiveness LED (10 J/cm~2, λ850 nm, 100 mW, CW) on the inflammation of the temporomandibular joint of rats induced by carrageenan. Thirty animals were divided in two groups with five animals per subgroup according to the experimental times of two, three and seven days: Inflammation and Inflammation + LED phototherapy. The first irradiation was performed 24 h after induction with an interval of 48 h between sessions. After animal death, specimens were processed and stained with HE and Picrosirius. Then the samples were examined histologically. Data were statistically analyzed. The inflammation group showed mild to moderate chronic inflammatory infiltrate among the bone trabecules of the condyle. Over the time-course of the study in the LED group the condyle showed aspects of normality and absent inflammation in some specimens. In all the time-points, no statistically significant differences were found for collagen deposition in the in the condyle and disc when LED was compared to Inflammation group. LED treated groups also demonstrated a smaller number of the layers of the synovial membrane when compared to the non-irradiated groups. It was concluded that, in general, LED phototherapy resulted in a reduction of inflammatory infiltrate in the temporomandibular joint of rat.