Evaluation of the effects of diode laser application on experimental orthodontic tooth movements in rats. Histopathological analysis.

PURPOSE: To evaluate the effect of diode laser use on experimental orthodontic tooth movements. METHODS: Thirty Rattus norvegicus albinus Wistar were divided into three equal groups (n = 10), two experimentals and one control. Applying 20 g orthodontic force were attached to the maxillary incisors of the rats in all groups. Low dose laser was applied to the surrounding tissues of the maxillary incisors of the rats in the experimental groups. Two exposure times for laser irradiation were used for seven days: t = 12 min (energy dose = 72 J) and t = 9 min (energy dose = 54 J) by a 0.1 W DEKA brand diode laser with wavelength of 980 nm. RESULTS: Osteoclastic activation increased in the 72 J group when compared to control group and decreased in comparison to the 54 J group. Osteoblastic activation was decreased in the 72 J group when compared to the control group and increased in comparison to the 54 J group. CONCLUSIONS: Applying 54 J laser energy has been found effective to accelerate the orthodontic tooth movement.

The effect of low-level laser therapy on the healing of hard palate mucosa and the oxidative stress status of rats.

OBJECTIVE: The biostimulation effects of low-level laser therapy (LLLT) have been demonstrated recently. This study investigated the effects of LLLT on palatal mucoperiosteal wound healing and oxidative stress status in rats. MATERIAL AND METHOD: Forty-two male Wistar rats weighing 250-300 g were used in this study. A standardized full-thickness wound was created in the mucoperiosteum of the hard palates of the rats using a 3-mm-diameter biopsy punch. Treatment using a GaAlAs laser at a wavelength of 940 nm and a dose of 10 J/cm(2) was initiated after surgery and repeated on the 2nd, 4th, and 6th days post-surgery. Seven animals from each group were sacrificed on the 7th, 14th, and 21st days after surgery. Total antioxidant status and total oxidative status were measured in serum. RESULTS: The histopathological findings revealed reduced numbers of inflammatory cells on the 7th day, increased mitotic activity of fibroblasts on the 14th and 21st day, and the same degree of collagen synthesis and vascularization on the days 7, 14, and 21 in the LLLT group compared with the control group. No significant differences in total oxidative status and total antioxidant status were observed between the groups. CONCLUSION: LLLT using a GaAlAs laser at a wavelength of 940 nm and a dose of 10 J/cm(2) elicited a positive healing effect on palatal mucoperiosteal wounds likely via the induction of fibroblasts. The oxidative stress status was not affected by LLLT.

The effects of low-level laser therapy on palatal mucoperiosteal wound healing and oxidative stress status in experimental diabetic rats.

OBJECTIVE: The biostimulation effects of low-level laser therapy (LLLT) have recently been demonstrated. In this study, we aimed to investigate the effects of LLLT on palatal mucoperiostal wound healing and oxidative stress status in experimental diabetic rats. MATERIALS AND METHODS: Forty-two male Wistar rats that weighed 250-300 g were used in this study. Experimental diabetes was induced in all of the rats using streptozotocin. A standardized full thickness wound was made in the mucoperiosteum of the hard palates of the rats using a 3 mm biopsy punch. The rats were divided into groups: 1 (control group, non- irradiated), and 2 (experimental group, irradiated). Treatment using a GaAlAs laser at a wavelength of 940 nm and at dose of 10 J/cm(2) began after surgery, and was repeated on the 2nd, 4th, and 6th days post-surgery. Seven animals from each group were killed on the 7th, 14th, and 21st day after surgery. Biopsies were performed for the histological analysis and blood samples were collected by cardiac puncture for biochemical analysis. RESULTS: The histopathological findings revealed reduced numbers of inflammatory cells, and increased mitotic activity of fibroblasts, collagen synthesis, and vascularization in rats in group 2. The total oxidative status was significantly decreased in the laser-treated group on the 21st day. CONCLUSIONS: LLLT elicits a positive healing effect on palatal mucoperiostal wounds, and modulates the oxidative status in experimental diabetic rats.