Ультраструктурна організація центральних ямок зубів

Abstract

Проведене детальне вивчення кутикули центральної ямки великих кутніх зубів на тонких поперечних шліфах гістохімічно забарвлених ШИК-тіонін-альціановим синім та за допомогою скануючої електронної мікроскопії. Встановлено, що ямка складається із серцевини, утвореної білковим фільтратом слинної рідини між атрофованими амелобластами. Межа між серцевиною та призмовою емаллю складається з тонких волокнистих структур насмітової оболонки; Проведенное детальное изучение кутикулы центральной ямки больших коренных зубов на тонких поперечных шлифах гистохимически окрашеных ШИК-тионин-альциановым синим и с помощью сканирующей электронной микроскопии. Установлено, что ямка состоит из сердцевины, образованой белковым фильтратом слюнной жидкости между атрофироваными амелобластами. Граница между сердцевиной и призменной эмалью состоит из тонких волокнистых структур насмитовой оболочки; Dental enamel is a thin layer which covers the surface of tooth crown and protects it from external damages which might occur in an oral cavity. The most vulnerable to the damages are deep areas of crown as pits and fissures. From the outside dental enamel is covered with a thin skim thin layer known as cuticle outside which consists of two sublayers: the sublayer atrophied ameloblast and the sublayer known as Nasmyth covering. The structure of sudental superficial cuticle has been much reported in the literature, while hipostructure and ultrastructure of cuticle sublayers and especially in pits and fissures is little studied. The research was aimed to study histochemical and ultrastructural characteristics of pits and fissures of molars. 10 upper and lower molars which were not affected by caries with +4 and Y-5 odontoglyphics pattern were under the study. The structure of pits was researched by using the transversal saw cuts. Thin slices of 20 - 30 mkm wide were polished in diamond paste and then were stained with PAS-tionin-alcian blue. In central fossula it allowed us to distinguish the followings areas: cuticle, core of pit and border between pit and prism enamel. It has been established that a pit is of round shape and surrounded the pinches of the parallell located enamel prisms, which are stained dark violet. Pit becomes separated from prisms by thin PAS-positive strip which passes gradually in the light fibred structures. They form framework of fossula core in which alcian- positive scales of different size and form are. We carried out ultrastructural studying of a fossulas by means of scanning electronic microscopy for the purpose of identification of its histologic structure. It is discovered on transversal edges, that a fossula has a core marked off from a prism enamel. A core consists of thin scales which have a shallow grittiness and small kernels. Besides, in a core existence of light homogeneous or fibrilyarny structures which are similar to proteinaceous components pellicula is noted. Light thin fibred structures is presented the special interest of ultrastructure of fossula which are on a limit with a prism enamel. Thus, it is necessary to claim that the pole represents double layer of cuticles. As it is known, outside the cuticle is covered with a thin proteinaceous film - pellikuly. In fossulas the proteinaceous filtrate of salivary liquid collects among atrophied ameloblasts, forming homogeneous masses of a core. Results of electronic microscopic researches confirm the point of view that poles of a tooth crown normally consist of a core formed by atrophied ameloblasts, and the border between a core and a prism enamel is formed by thin fibrous structures which, in our opinion, represents Nasmyth cover.