CARACTERIZAÇÃO DO MODELO DE PERDA ÓSSEA ALVEOLAR INDUZIDA POR LIGADURA EM RATOS

• Autor(a) principal: Sanchez, Paula Katherine Vargas
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UEPG
• Texto Completo: http://tede2.uepg.br/jspui/handle/prefix/1709
• topic: modelo animal; ligadura; perda óssea alveolar; animal model; ligature; alveolar bone loss; CNPQ::CIENCIAS DA SAUDE::ODONTOLOGIA

Peridontal research involves the use of animal models to facilitate the understanding of biological processes of periodontal disease (PD), and the potential of new and existing therapies, therefore the induction of periodontal disease is needed. In the literature, the most widely used model for the induction of periodontal disease in rats is ligature. It is an insertion of a cotton yarn around the cervix of the first mandibular molar resulting in the accumulation of a bacterial biofilm, and triggering a local inflammatory response and the consequent alveolar bone loss (ABL). The methods most commonly used to evaluate the ABL are radiographic, histologic and morphometric. Which measure the distance between the cemento-enamel junction and bone crest. Although these methods are widely used, it is unknown the possibility of extrapolating resuts between research groups and the intra-examiner (repeatability) and inter-examiner (reproducibility) agreement. Other parameters usually assessed are leukocyte migration (MPO) and the presence of nitric oxide (NO), which are inflammatory markers. The aim of this study was characterized the kinetics of the ABL, leukocyte migration and nitric oxide at 0, 3, 7, 15, 30 and 60 days after induction of PD by ligature and evaluate the Bland-Altman concordance for the main assessment methodologies of ABL (radiographic, histologic and morphometric). 60 male Wistar rats between 250 and 300 g were randomly divided into 6 experimental groups (n = 10 animals /group) as follows: G0 (not treatment), G3 (ligature for 3 days) G7 (ligature for seven days) , G15 (ligature for 15 days), G30 (ligature for 30 days) and G60 (ligature for 60 days). After 0, 3, 7, 15, 30 and 60 days, animals were sacrificed by anesthetic overdose, and hemimandibles were removed for radiographic analysis, morphometric (linear and area) and histological. Also was collected adjacent gum tissue from mandibular first molar for leukocyte migration analysis and nitric oxide dosage. The results were analyzed with ANOVA followed by Tukey test and Bland Altman test to establish the correlation between the methodologies. In the radiographic analysis was observed a significant ABL after the third day, the intra-examiner and inter-examiner analysis showed a significant difference between the measurements. In linear morphometric analysis, the ABL was significant after the third day, in contrast to measure the area was significant only after the seventh day. The concordance analysis intra and inter-examiner did not show difference between these measurements. In histological measurement, the ABL was significant after the seventh day. The intra and inter-examiner analysis showed no difference between the measurements. The leukocyte migration had significant difference on the seventh day and the nitric oxide showed a peak of activity in the fifteenth day. It is concluded that radiographic analysis and morphometric-linear had a significant ABL on the third day, in contrast to morphometric-area and histological showed a significant ABL after the seventh day of induction. The peak of MPO activity occurs seven days after the induction of disease, for NO the peak occurs on the fifteenth day. In addition it was observed an agreement of Bland Altman intra and inter-examiner for the morphometric and histological methods. But the radiographic method did not show intra- and inter-examiner concordance.