Histological Evaluation of Wound Healing Process after Photodynamic Therapy of Rat Oral Mucosal Ulcer.

STATEMENT OF THE PROBLEM When the body defense is compromised, wounds can act as a route for entrance and colonization of microorganisms in the body. Photodynamic therapy with methylene blue is known as a promising antimicrobial modality. PURPOSE The present study aimed to investigate the effects of this procedure on wound healing processes. MATERIALS AND METHOD In this experimental study, 48 male Wistar rats were recruited. Experimental wounds were surgically made on their buccal mucosa. Based on the treatment modality, they were divided into 3 groups (n=16) of control (CG), laser (LG), photosensitizer+ laser (PLG) by methylene blue (MB). The treatment procedure in the two latter groups was done in days 1-4 and 6-9. After sacrificing on 2, 4, 7 and 14-day follow-ups, the microscopic grade of healing of the wounds was assigned on each interval according to histological grading criteria. RESULTS A qualitative result was obtained that showed a healing progression in PLG at day 2 of follow-up. At day 4 of follow-up, no difference was seen in healing stage among the groups. However on day 7 of follow-up, samples of the LG showed a lower degree of healing compared with the other two groups. Likewise, on day 14 of follow- up, both PLG and LG showed lower degree of healing than CG. CONCLUSION This study qualitatively showed that MB- mediated photodynamic therapy would have an inhibitory effect on healing process after 14 days of the wound creation.