RESUMO
Objective To observe the effect of different energy levels of pulsed Nd∶YAG laser irradiation on the changes of NO and NOS levels in ulcer tissue of oral ulcer model.Methods Forty-eight Sprague-Dawley rats were inflicted with oral ulcer,and then randomly and equally assigned to 6 groups,that is,oral ulcer group,1% iodine glycerin group and the rest 4 groups receiving pulsed Nd∶YAG laser irradiation at 1.5 W 40 mJ,1.5 W 60 mJ,1.5 W 80 mJ or 1.5 W 100 mJ(once per day,for 3 consecutive days).The other 8 rats served as normal control.In 24 h after last treatment,4 rats from each group were sacrificed and their cheek pouches were taken out for NO and NOS levels in the mucosal tissue by spectrophotomentry.Ulcer healing were observed 24 h after the last treatment for 8 consecutive days.The efficiency of Nd∶YAG laser irradiation at different powers were evaluated.Results Irradiation groups had significantly shorter healing time compared with iodine glycerin group.Level of NO and NOS activity in 1.5 W 60 mJ and 1.5 W 80 mJ groups was evidently lower than the ulcer group(P
