Avaliação histológica das abrasões gengivais promovidas por escovação no cão

Abstract

Gingival abrasions are associated with toothbrushing. Little is known on the histological nature of these lesions. Objective: To evaluate the histological changes in the gingiva present immediately, 4, 8 and 24 hours after a single toothbrushing episode. Methods: Three healthy mongrel female dogs were initially treated with a full dental prophylaxis. One week later, toothbrushing using a modified single tufted brush were performed for 30s involving the buccal area of the second premolars. Biopsies were obtained by means of full thickness flaps. After regular histological processing, specimens were included in paraffin and three 4um sections of the central area of the corresponding lesions and one section adjacent as a control, were stained with hematoxilyn and eosin. The images were captured in the Image-Pro Plus 5.1® program and examined with a x100 objective. The thickness of the epithelium was measured in 5 different sites along the abraded area. Similar measurements were taken in control areas not involved by brushing contiguous to the lesions. The sum of the vascular area was calculated adding the individual areas of vases present in the connective tissue of each section. The means for the thickness of the epithelium and the percentage of vascular area observed at the different time intervals were compared with ANOVA whereas differences between tests and corresponding controls at each time interval were compared using the t-test (p<0.05). Results: The thickness of the epithelium at the abraded areas was 922,7μm immediately after brushing, 1301,9μm after 4 hours, 1271,1μm after 8 hours and 1280,3μm after 24 hours. The control areas means were 1925,9μm, 2246,5μm, 2069,5μm, 1473,1μm for the same observation intervals. Epithelium thickness was significantly reduced at all time intervals as compared to their controls, except in 24 hours. In the intragroup analysis there weren t observed statistically significant differences for tests, neither for controls. The percentage of vascular area in relation to the connective tissue area was 5,14% immediately after, gradually reduced to 1,25% up to 8 hours with a small increase to 2.3% at 24 hours. Conclusion: Gingival abrasions associated with a single brushing episode are mostly epithelium lesions with a significant reduction in thickness showing a tendency to recovery after 8 hours of observation.