Sarkisian E. Comparative morphology of laboratory animals and humans teeth in terms of carious disease

The thesis is devoted to the theoretical study of the problems of the morphological similarities and specific differences between the teeth of humans and some laboratory animals (dogs, rabbits and white rats), setting the target of which was the establishment of the most appropriate species for the experimental simulation of carious disease. We justify the provision according to which resistance to abrasion of the teeth of both types (shortcrown and longcrown teeth) is carried out not only by the exceptional hardness of enamel, but also the stability of elastic dentin which are composed in teeth in a particular composite regard in which enamel is used as a hardener dentin ( reinforcement material principle). In shortcrown teeth total stock of composite strength (durability) genetically limited height of the crown, and feature configuration of the occlusal surface. In such engagement teeth dentin wear in abrasive process begins after erasing the thickest layer of enamel on the occlusal elevations mounds. At the same time the enamel thickness is directly dependent on the duration of animal life. In contrast, in longcrown tooth dentin initially (after the eruption) is a state in the nude on the occlusal surface, they find themselves exposed to abrasive abrasion. These teeth during life have virtually unlimited supply of durability due to constant regrowth. Due to the permanent renewal of their hard tissues completely exclude the possibility of proof of damage and the carious process. To this category belong entirely rabbit teeth, and front (incisal) rat teeth. Characteristic species difference in the teeth-jaw system of rats from that of the rabbit, is that the first indigenous animals (cheek) teeth in shape - it three-root squaretuberkular formation, which in the main are the miniature likeness of human molars. From this we can assume that the experimental simulation of carious disease on white rats are able to provide the desired results. But their morphological visualization will be difficult in many respects due to too small crown size (only about 2 mm) of the molars, which alone can be morphologic substrate of carious lesions. Overcoming this difficulty it can be solved by using morphological methods, which are used in this thesis.