During the inflammatory process some kinds of cells are predominant and are involved with pain production. Low power laser seems to be useful in the control of inflammatory mediators, but wide divergence in the dosemetric parameters leads to variations in its positive results. The aim of this study was to assess the use of the 808nm laser in the chronic joint pain and edema of Wistar rats submitted to synovitis. Sample was composed of 10 Wistar rats divided in two groups: CG - synovitis induction on right knee and placebo treatment; TG - synovitis induction and irradiated with 10J/cm² laser. 100µl of 5% phormaline were injected in the right tibiofemoral joint space. Pain assessment occurred by the time of paw elevation (TPE). On the 10th day after synovitis induction, laser treatment began on the knee medial joint surface and this procedure was kept for 10 days. The outcomes showed that laser presented analgesic effects, since significant reduction of the TPE values was observed for the treated group, hence indicating pain reduction when compared with the pre-treatment values; the same situation did not occur to the group which received the placebo treatment. Concerning edema, laser has also shown significant reduction. It can be concluded that laser 808nm with 10J/cm² is efficient in reduction of chronic joint pain and edema in animals submitted to experimental synovitis.
low power laser; arthralgia; edema
