Thermographic and clinical evaluation of 808-nm laser photobiomodulation effects after third molar extraction.

BACKGROUND: A randomized, blind, controlled clinical study was conducted with a convenience sample of 24 patients to evaluate the effectiveness of an aluminum gallium arsenide (AlGaAs) infrared laser 808 nm after third molar extraction by the use of infrared thermography technique. METHODS: Patients were divided into four groups: erupted third molars were extracted from the patients in Group I and Group II, and impacted third molars were extracted from the patients in Group III and Group IV. Group I and Group III received mock laser therapy in which the device was powered off, and Group II and Group IV were exposed to laser light. Postoperative clinical parameters related to the third molar extraction were evaluated; these parameters included pain, trismus and edema. Circulatory patterns were also evaluated by infrared thermography that exhibited local temperature coefficient at different postoperative periods. RESULTS: A slight improvement was observed for swelling, pain and trismus in patients who received laser irradiation, although the differences were not statistically significant (P>0.05). Laser therapy had a significant influence on the local circulation in the area near the temporomandibular joint, as determined by infrared thermography (P<0.05). CONCLUSIONS: Laser therapy was able to change the local circulation, although it did not significantly influence swelling, pain or trismus during the postoperative period.

Mast cells and its relation to collagen and VEGF in oral inflammatory lesions.

BACKGROUND: The aim of this study was to evaluate the population of intact and degranulated MCs in oral inflammatory lesions. METHODS: A cross sectional study of 48 samples, including inflammatory fibrous hyperplasia, pyogenic granulomas, periapical granulomas and radicular cysts, was performed. Samples of normal gingival mucosa were used as controls. The degree of edema and lymphoplasmacytic infiltrate was determined by the analysis of hematoxylin-eosin (HE)-stained sections. To determine the collagen fibers contents and correlate it with the MC count, sections stained with Sirius red and Toluidine blue were used. Immunohistochemistry with an antivascular endothelial growth factor (VEGF) was also used to count endothelial cells. RESULTS: Although the total number of intact MCs was higher in the oral inflammatory lesions, these differences were not statistically significant (P=0.33). There were statistically significant differences between the numbers of degranulated MCs from the lesions and those from the normal oral mucosae (P=0.001) and a positive correlation between the number of MCs and the degree of inflammation (P<0.001). The MC count did not correlate with the collagen fibers or VEGF positive cells (P>0.05). CONCLUSIONS: The involvement of MCs in the pathogenesis of the oral inflammatory lesions is suggested. However, there was no positive correlation with these cells and collagen fibers or angiogenesis in the lesions studied.