BACKGROUND:The laser applied in the clinical oral medicine is mainly for early diagnosis of caries, removal of carious tissue, pulpotomy for pulp bleeding, dentin hypersensitivity treatment, disinfection of infected root canals, and periodontitis treatment. OBJECTIVE:To explore the changes of basic fibroblast growth factor in inflammatory pulp after laser treatment. METHODS:Five healthy adult beagle dogs were enroled, and six teeth were randomly selected from each dog. Then, these teeth were randomly divided into three groups, 10 teeth in a group, and they were treated with laser irradiation, saline and gentamicin irrigation respectively. At days 1, 2, 3 after operation, exudates from the pulp were colected for detection of basic fibroblast growth factor expression. Meanwhile, the dental pulp was detected by hematoxylin-eosin staining and immunohistochemistry method. RESULTS AND CONCLUSION:In the al three groups, the expression of basic fibroblast growth factor at day 3 was significantly higher than that at days 1 and 2, and there were no differences between days 1 and 2. Moreover, these three groups also showed no significant differences. Under hematoxylin-eosin and immunohistochemical staining, blood vessels in the pulp cavity were in good condition and the pulp arranged tightly. These findings suggest that the laser is safe, convenient and effective for oral clinical application, and has no injury to the inflammatory pulp.