Morphological changes in different sites of tooth in modeled median caries in rats

Визначення ступеня розвитку запального процесу в пульпі зуба обумовлює визначення тактики ендодонтичного лікування, що відповідало б принципам "біологічної доцільності", забезпечивши ви- дужання пульпи, збереження життєздатності всієї або кореневої її частини. В роботі описані мор- фологічні зміни дентину та пульпи зуба при експериментальному середньому карієсі у щурів. Встановлено, що деструктивні процеси проявляються у вигляді набряку надодонтального прос- тору і мають зворотній процес в цервікальній частині пульпи. В той час як адаптаційні зміни в цій ділянці супроводжуються розвитком прозорого дентину, зумовленого проліферацією одонтоблас- тів. Одночасно з цим безпосередньо в пульпі спостерігається проліферація фібробластів, що в по- дальшому сприяє розвитку замісного дентину.; The pulpitis is the most common complication of caries. It develops due to the penetration of microorganisms and their toxins from a carious cavity into a dental pulp though dentinal tubules. Solving the question on the condition of a pulp and on the choice of the method for pulp treatment which would correspond to the "biological appropriateness" and would provide pulp recovery is still remaining urgent. The research was aimed to study morphological changes of dental pulp in case of experimental average caries in rats. The research was carried out on histochemically stained thick sections of teeth and decalcified slices of teeth stained by conventional techniques. According to the results of epimicroscopic researches of thick sections, histochemical stained with PASalcian blue, the zone of the destroyed dentine is presented in the form of the PAS-positive site under which there is alcian-positively painted destructively changed dentine with a subject zone of a transparent dentine. Sites of the kept dentine are painted in light pink color. The pulp of crown part is presented by sharply hyperemic vessels. In its ostium part they are less hyperemic. And in root part they do not differ from such at the control group. The results of researches of the decalcified specimen stained by hematoxylin and eosine testify that medial caries manifests expressed destructive changes in a dentine of crown part of a dental pulp. Along enamel-dentin junction it is noted granular disintegration of odontoblasts processes and deep necrobiotic processes in the form of emergence so-called "dead ways". Under this zone there is a strip of a transparent dentine which is characterized by expanded gleams of dentinal tubules in which calcium salts are postponed. The predentin zone is characterized by uneven adjournment basphilic and homogeneous eosinophilic substances in dentinal tubules. Pulp reaction at average caries is shown by loss of a multillayer structure of odontoblasts nucleus. Pulp reaction in ostium part is characterized by a hyperemia of microvessels and hypostasis of overodontoblasts space in which there are thinned odontoblasts processes. Intact odontoblasts have slanting or vertical orientation. Under odontoblasts there is a layer of fibroblast with high proliferative activity. We came to a conclusion that median caries was observed on the 84th day of experiment. In ostium part of a pulp, unlike crown part, we noted destructive and adaptation processes. Destructive processes were shown by hypostasis of overodontoblasts space and could be reversible. Adaptation changes in this site were accompanied by formation of a transparent dentine that was caused by proliferation of odontoblasts. At the same time in a pulp proliferation of fibroblast was observed that accompanied the formation of a replaceable dentine