Effects of the photobiomodulation using different energy densities on the periodontal tissues under orthodontic force in rats with type 2 diabetes mellitus.

To evaluate the impact of the GaAlAs diode laser with energy densities of 160 J/cm2, 320 J/cm2, and 640 J/cm2 on the periodontal tissues under continuous orthodontic force application and on the rate of orthodontic tooth movement in rats with type-2 diabetes mellitus. The intensity of primary alveolar bone formation was also investigated through the immune-positive osteocytes for OPN antibody. Forty adult male Wistar rats were divided into eight groups of 5 rats: normoglycemic (N), 160 J-laser-normoglycemic (160 J-LN), 320 J-laser-normoglycemic (320 J-LN), 640 J-laser-normoglycemic (640 J-LN), diabetic (D), 160 J-laser-diabetic (160 J-LD), 320 J-laser-diabetic (320 J-LD), and 640 J-laser-diabetic (640 J-LD) rats. Diabetes mellitus was induced by a single intravenous injection of 40 mg/kg monohydrated-alloxan. An orthodontic force magnitude of 20cN was applied. The laser parameters were continuous emission of 780-nm wavelength, output power of 20mW, and fiber probe with a spot size of 0.04 cm in diameter. Radiographic, histomorphological, and immunohistochemical analysis were performed after a period of 21 days. The photobiomodulation using the energy density of 640 J/cm2 strongly stimulated the alveolar bone formation and contributed the reorganization of the soft periodontal tissues, followed by the 320 J/cm2. Extensive alveolar bone loss, intense infiltration of inflammatory cells, and degradation of the PDJ tissue were mainly found in the D and 160 J-LD groups. The rate of orthodontic tooth movement was represented by the interdental distance between the cementoenamel junctions of the right mandibular first and second molars . This distance was larger in the diabetic groups (D: 39.98±1.97, 160 J-LD: 34.84±6.01, 320 J-LD: 29.82±1.73, and 640 J-LD: 35.47±4.56) than in the normoglycemic groups (N: 21.13±1.19; 160 J-LN: 22.69±0.72, 320 J-LN: 22.28±0.78, and 640 J-LN: 24.56±2.11). The number of osteopontin-positive osteocytes was significantly greater in the 640 J-LD (14.72 ± 0.82; p < 0.01) and 640 J-LN (13.62 ± 1.33; p < 0.05) groups than with D (9.82 ± 1.17) and 160 J-LD (9.77 ± 1.10) groups. Therefore, the energy density of 640 J/cm2 provided the best maintenance and integrity of the periodontal tissue microarchitecture under continuous orthodontic force when compared with the other dosages, mainly in the uncontrolled diabetic rats. The interdental distance was greater in the D and 160 J-LD groups due to presence of severe periodontitis caused by diabetes plus the mechanical stress generated by continuous orthodontic forces, implying, thus, an insufficient biostimulatory effect for the dosage of 160 J/cm2.

Effects of the photobiomodulation using different energy densities on the periodontal tissues under orthodontic force in rats with type 2 diabetes mellitus

Abstract To evaluate the impact of the GaAlAs diode laser with energy densities of 160 J/cm2, 320 J/cm2, and 640 J/cm2 on the periodontal tissues under continuous orthodontic force application and on the rate of orthodontic tooth movement in rats with type-2 diabetes mellitus. The intensity of primary alveolar bone formation was also investigated through the immune-positive osteocytes for OPN antibody. Forty adult male Wistar rats were divided into eight groups of 5 rats: normoglycemic (N), 160 J-laser-normoglycemic (160 J-LN), 320 J-laser-normoglycemic (320 J-LN), 640 J-laser-normoglycemic (640 J-LN), diabetic (D), 160 J-laser-diabetic (160 J-LD), 320 J-laser-diabetic (320 J-LD), and 640 J-laser-diabetic (640 J-LD) rats. Diabetes mellitus was induced by a single intravenous injection of 40 mg/kg monohydrated-alloxan. An orthodontic force magnitude of 20cN was applied. The laser parameters were continuous emission of 780-nm wavelength, output power of 20mW, and fiber probe with a spot size of 0.04 cm in diameter. Radiographic, histomorphological, and immunohistochemical analysis were performed after a period of 21 days. The photobiomodulation using the energy density of 640 J/cm2 strongly stimulated the alveolar bone formation and contributed the reorganization of the soft periodontal tissues, followed by the 320 J/cm2. Extensive alveolar bone loss, intense infiltration of inflammatory cells, and degradation of the PDJ tissue were mainly found in the D and 160 J-LD groups. The rate of orthodontic tooth movement was represented by the interdental distance between the cementoenamel junctions of the right mandibular first and second molars . This distance was larger in the diabetic groups (D: 39.98±1.97, 160 J-LD: 34.84±6.01, 320 J-LD: 29.82±1.73, and 640 J-LD: 35.47±4.56) than in the normoglycemic groups (N: 21.13±1.19; 160 J-LN: 22.69±0.72, 320 J-LN: 22.28±0.78, and 640 J-LN: 24.56±2.11). The number of osteopontin-positive osteocytes was significantly greater in the 640 J-LD (14.72 ± 0.82; p < 0.01) and 640 J-LN (13.62 ± 1.33; p < 0.05) groups than with D (9.82 ± 1.17) and 160 J-LD (9.77 ± 1.10) groups. Therefore, the energy density of 640 J/cm2 provided the best maintenance and integrity of the periodontal tissue microarchitecture under continuous orthodontic force when compared with the other dosages, mainly in the uncontrolled diabetic rats. The interdental distance was greater in the D and 160 J-LD groups due to presence of severe periodontitis caused by diabetes plus the mechanical stress generated by continuous orthodontic forces, implying, thus, an insufficient biostimulatory effect for the dosage of 160 J/cm2.

Avaliação imuno-histoquímica da remodelação óssea alveolar em ratos diabéticos durante a movimentação ortodôntica associada à laserterapia / Immunohistochemical evaluation of alveolar bone remodeling in diabetic rats during orthodontic movement associated with laser therapy

O Diabetes mellitus é um distúrbio metabólico crônico e sua prevalênciavem aumentando de forma exponencial, particularmente nos países em desenvolvimento. Concomitantemente tem aumentado a acessibilidade ao tratamento ortodôntico, incluindo pacientes diabéticos, tornando o processo de remodelação óssea frente aos estímulos ortodônticos motivode grande preocupação. A procura por meios que possam melhorar esse processo é uma realidade atual, a aplicação do laser de baixa potênciadurante a movimentação ortodôntica pode ser de grande valia, principalmente com o descontrole glicêmico. Desta forma o objetivo deste trabalho foi analisar por meio de reações imuno-histoquímicas, o processo de remodelação óssea alveolar, decorrente do movimento ortodôntico em ratos diabéticos e a influência da aplicação do laser de baixa potência As GaAl durante o período experimental de 7, 14 e 21 dias. Foram utilizados 60 ratos machos Wistar, divididos em 4 grupos por período: Grupo Controle (C), Grupo Laser (L), Grupo Diabetes (D) e Grupo Diabetes-Laser (D-L). Para a indução do diabetes foi utilizada uma dose única de aloxano (40mg/kg), a glicemia foi mensurada e sendo os ratos considerados diabéticos foram submetidos a uma força ortodôntica de20cN, assim como todos os animais dos grupos (C) e (L). Os grupos (L) e(D-L) foram tratados com laser de baixa potência AsGaAl em dias intercalados até a eutanásia. Foram realizadas análises histomorfológicas, reação imuno-histoquímica e histomorfometria para os anticorpos RANK-L e OPG do primeiro molar inferior direito, submetido à movimentação ortodôntica. Os dados obtidos foram analisados estatisticamente mediante os testes de variância (ANOVA) e TUKEY (P<0,05). Diante dos resultados obtidos, pode-se concluir que houve efetividade da radiação laser As GaAl durante a movimentação ortodôntica, visto que, a fisiopatologia do diabetes não interferiu na integridade dos tecidos periodontais e no processo de remodelação óssea alveolar

Diabetes mellitus is a chronic metabolic disorder and its prevalence hasbeen increasing exponentially, particularly in developing countries. At the same time the accessibility to orthodontic treatment has increased,including diabetic patients, making the point of process of bone remodeling in the face of orthodontic stimuli of great concern. The search for ways they can improve this process is a current reality, the application of low power laser during orthodontic movement can be of great value, especially with the loss of glycemic control. Thus, the objective of this study was to analyze by immunohistochemical reactions, the process of alveolar bone remodeling, due to orthodontic movement in diabetic rats and the influence of application of low power laser Ga AlAs during the experimental period of 7, 14 and 21 days. Sixty male Wistar rats we redivided into four groups: Control (C), Laser Group (L), Diabetes Group (D)and Diabetes Group-Laser (DL). For the induction of diabetes a single dose of alloxan (40mg/kg) was used, considered diabetic by blood glucose measure nurts and the molar was subjected to a force orthodontic 20cN aswell as all the animals of group (C) and (L .) Groups (L) and (DL) were treated with low power GaAlAs laser every other day until euthanasia. Analyzes were performed by histomorphology, immunohistochemistry and histomorphometry for antibodies RANK-L and OPG in the mesial anddistal and mesial interradicular septum of the interdental septum of the alveolar bone of the lower right first molar, subjected to orthodontic movement. The data were statistically analyzed by means of tests ofvariance (ANOVA) and Tukey is tests (P<0.05). Based on these results, itcan be concluded that there was effectiveness of GaAlAs laser radiation during orthodontic movement, since the pathophysiology of diabetes didnot affect the integrity of the periodontal tissues and alveolar bone remodeling process