Avaliação de ansiedade em ratos com lesão periapical

Abstract

The aim of this study was to investigate if induced periapical lesion in rat molars can lead to behavioral changes in these animals. Eighty-one male Wistar rats were used, with approximately 45 days of age, 27 animals were used as control (Control), 27 were submitted to a coronary opening and exposure of the pulp to root canal contamination and left open for 7,15 and 30 days (CCA), and 27 were submitted to a coronary opening and exposure of the pulp and left for 7,15 and 30 days and after the experimental period the tooth was closed with composite resin and kept closed for 7 more days (CCF). All analyzes were performed at 7, 15 and 30 days. The behavioral tests used in this study were the Elevated Plus Maze (LCE) and Open Field (CA). Both were applied at the beginning and at the end of each experimental period. After the experimental period the animals were sacrificed by anaesthetic overdosage, and the jaws were removed, sectioned and fixed for further radiographic and histologic analysis.. The analysis of variance (ANOVA) two criteria was used for animal behavior data. In the CCF group the t student paired test was used for comparisons between before and after close the tooth with composite resin. For all tests, the significance level was 0.05. Induced periapical lesions led to behavioral changes in animals, showing probable increase in the level of anxiety, in the CCA group, up to 15 days after induction, and the FCC group, in all periods, mostly at 30 days. The animal model utilized showed satisfactory in inducing inflammatory periapical lesions. The radiographic and microscopic findings were in accordance. Periapical lesions induced in rats in both test groups (CCA and CCF), had significantly higher radiolucent areas compared to the control group, presence of pulp necrosis, bone resorption and polymorphonuclear inflammatory infiltrate at all periods (7, 15 and 30 days). The CCA group exhibited microabscesses at 7 and 30 days and intense bone resorption within 15 days, and the CCF group, microabscesses formation at 15 and 30 days.