TESIS DE DOCTORADO Enfermedad periodontal...
Periodontal disease (PD) is a process of progressive loss of tooth-supporting structures, being established as the most common disease in adult dogs and cats. Many studies have used the scanning electron microscope (SEM) to describe the characteristics of dentin and cementum in human teeth. However,...
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| Formato: | Tesis doctoral acceptedVersion |
| Lenguaje: | Español |
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Universidad de Buenos Aires. Facultad de Ciencias Veterinarias
2015
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| Acceso en línea: | http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=avaposgra&cl=CL1&d=HWA_1473 https://repositoriouba.sisbi.uba.ar/gsdl/collect/avaposgra/index/assoc/HWA_1473.dir/1473.PDF |
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| Sumario: | Periodontal disease (PD) is a process of progressive loss of tooth-supporting structures, being established as the most common disease in adult dogs and cats. Many studies have used the scanning electron microscope (SEM) to describe the characteristics of dentin and cementum in human teeth. However, very few have been carried out in relation to dentin of dog teeth and none in relation to the cementum of healthy teeth or involved in PD. Neither have been reported in this species, studies that evaluate the effectiveness of the different instruments used for scaling and root planning in PD. The aim of this study was to describe the structural characteristics of dentin and cementum in permanent, healthy and mature teeth of dogs and those involved in periodontal disease (PD); also their modifications due to the periodontics therapy, and to determine the prevalence of this disease in our environment. For the study of the dentin, 36 normal teeth undergoing various occlusal forces, extracted from 12 dogs of two specific age groups, and six canines from different dogs older than 7 years old, involved in severe periodontal disease, were observed with the scanning electron microscope (SEM). The shape, diameter and density of the dentinal tubules were evaluated as well as the area occupied by them. Digital photomicrographs of the buccal surface of the pulp cavity, at different levels, of healthy and involved with PD teeth were taken. The following results were obtained: the diameter and area of the tubules decreased in a coronoapical direction; the diameter and area of tubules decreased as age increased; tubule density decreased in a coronoapical direction; tubule density was neither influenced by age nor by occlusal function; no significant differences were found between the dentin of the pulp cavity of normal teeth and those involved in severe periodontal disease.\nRegarding the cementum of healthy teeth, the buccal surface of 38 dental roots was observed and photographed with the SEM in their coronal and apical thirds. A morphological classification of the surface was performed and the Sharpey fiber diameter was measured, establishing the percentage occupied by them in a determined surface. In the coronal third, acellular cementum was found with the Sharpey fibers closely packed, projecting perpendicular to the surface, occupying almost the whole of it. The diameter of the fibers was of 5.31 ± 0.98 ?m. In the apical third, cellular cementum was found, with a density of Sharpey fibers less tham 55%, the remainder being intrinsic fibers and cell lacunae. The fiber diameter was 5.47 ± 1.31 ?m. The diameters of Sharpey fibers of the apical third were significantly higher than those in the coronal one. We conclude that the dog cementum surface is not uniform, being differences between coronary and apical thirds and within the same third of the tooth.\nAs regards to the cementum of teeth involved in periodontal disease, the study was directed mainly towards the presence and characteristics of root resorption caused by PD. 43 tooth roots involved in different levels of periodontal disease, determined clinically and radiographically, were observed with the SEM. The number of root resorptions, their area, the percentage of area resorbed on each radicular third, the invasion of dentin and the radiographic evidence of resorptions were assessed in each tooth. The predominant location of all resorptions was the coronal third. Teeth diagnosed with severe periodontitis (group 4) showed a higher number of resorptions and a higher percentage of resorbed area. The size of the resorption was higher in the apical third. A low percentage of resorptions (11.7%) reached the dentin and only those extremely large and deep were detected radiographically .\nThe effectiveness of the tools frequently used in veterinary medicine for root scaling was evaluated using SEM. 28 tooth roots involved in severe periodontal disease and with gingival retraction higher than 3 mm were used. The roots were divided into 4 groups, applying to each of them, different treatments: ultrasonic scaler and curettes- both methods with and without polishing the surface treated. Micrographs of 2 different areas were taken, and then rated according to a modification of the remaining calculus index and the loss of tooth substance index (Lie, 1985). Ultrasonic scaler with subsequent polishing proved to be the most efficient treatment. Several epidemiological studies carried out around the world indicate that PD is the most common disease in adult dogs. Due to the lack of information concerning the epidemiology of the PD in our country, it was considered to include it in this study. Information was collected from 114 dogs, in which a complete periodontal examination was performed. Also the age, weight, breed, cranial conformation, food and concomitant diseases were recorded. The prevalence of PD was 93.9 %; positive correlation between PD and age of the animals and negative correlation between the PD and the body weight was found. No association between periodontal disease and the type of food, chewing habits, cranial conformation, occlusion and concomitant diseases was found. |
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