Efectos de la diabetes en el movimiento dentario ortodóncico

Résumé

Objective: The aim of this study was to evaluate the influence of diabetes on oxidative stress, periodontal ligament (PDL) orientation, and metalloproteinases (MMPS) 8 and 9 expression during orthodontic tooth movement in a rat model. Methodology: An orthodontic appliance was placed in 60 Sprague-Dawley rats and they were divided into three groups randomly (n=20): 1) Normoglycemics, 2) Untreated-diabetics and 3) Diabetics insulin-treated. At 24, 48 and 72 hours, and 7 days after de appliance activation rats were sacrificed. At each time point, myeloperoxidase (MPO) and malondialdehyde (MDA) were quantified by spectrometry, tooth movement was evaluated by micro-CT, PDL fibers orientation was assessed with hematoxylin and eosin staining and MMP- 8 and MMP-9 was determined with inmunohistochemical staining and a semiquantitative 'H-Score' analysis. Results: At 24 hours, MPO activity was significantly higher in untreated diabetics rats than in normoglycemics. At 24 and 48 hours the MDA level in untreated-diabetics was significantly higher than in normoglycemics and diabetics insulin-treated. At 72 hours and 7 days, PDL fibers were oriented significantly more irregularly in untreated-diabetic than in normoglycemics rats. At all-time points, MMP-8 and MMP-9 expression was significantly higher in both diabetic groups than in the normoglycemics. After the second day, the tooth movement was significantly greater in untreated-diabetics than in diabetics insulin-treated and normoglycemics rats. Conclusions: Mechanical stress in untreated-diabetics rats produces more inflammatory response, oxidative stress, tooth movement, PDL disorganization, and a greater MMP-8 and MMP-9 expression than among normoglycemics rats. Insulin reverses partially the effects of diabetes favoring the PDL reorganization.