The blood supply of the pulp and the periodontium is intricate and very rich. The explanation of why there is still no exact and detailed description of the anatomy of the blood supply to these tissues, though it has been the topic of research for several years, lies in the fact that it is extremely difficult to gain access to the vessels inside the pulpal chamber and in the periodontal membrane.Up to now the vascular anatomy has been studied mostly on histologic specimens. This method may be successful in cases where the vascular pattern is less intricate, e.g., in the pulp, but it is inadequate to demonstrate in this way a more complex vascular network of the periodontium.The authors who investigated the pulpal vessels were of the opinion that the main vessels are situated in the center and branch off toward the periphery, where they form a capillary network below the odontoblasts.'3 They disagreed, however, on the manner of arborization and on the shape and density of the meshes in the capillary network. Only Sulzmann4 found epitheloid cells in the pulp of a dog's canine, and he believed that they regulated the blood flow in the pulp.As regards the vessels of the periodontium, two main questions have been followed up: first, the basic anatomic distribution of the vessels and, second, the localization, kind, and significance of the special vascular formations in the periodontal membrane. Each author approached the problem differently and drew different conclusions. Jesensky2 studied the vascular supply of the tooth during its development. In the periodontal membrane of the tooth with a completed development he described a coarse, vascular network that surrounded the root and emitted capillaries for the nutrition of the tissues; the capillaries formed a network that was loosest in the central part of the alveolus and densest at its margin, where it passed into the gingival vessels. Boehl5 was in search of the relation between the vascular outlay and the thick periodontal ligaments. He assumed that the vessels were thinly scattered at the sites of the thick ligaments. Above the ligamentum interdentale they form, however, a dense network that in Boehl's opinion, insures the turgor of the tissue at the site of the gingival attachment. He described the densest network in the periodontal membrane, in the central part of the alveolus. The vessels supplying the periodontal membrane entered, in his opinion, the alveolus at the apex and at the central and marginal part. Hayashi,6 though he used a different terminology, described the course of the afferent periodontal vessels in much the same way. Both authors admitted the possibility of a different vascular distribution in different teeth or on different sides of the root. There are many descriptions of special vascular formations in the periodontal mem-
The dental pulp of the rat incisor differs substantially from the pulp of completely developed teeth; nevertheless, under certain conditions it may respond in a similar way. One of the reactions resembling that of the pulp of completely developed teeth is the formation of pulp stones. Pulp stones have not been found in the pulp of the rat incisor with normal or enhanced eruption.In investigations of histological preparations of rat incisors with eruption arrested after 90 days, we found an oval pulp stone in transverse sections, near the basal end. Serial sections revealed that the pulp stone was not connected to the dentin wall (Illustration). The center of the stone contained cell remnants and occasional cavities. Layers of tubular dentin of different thickness were observed around this nucleus.On the periphery there was an irregular margin of pink predentin. In a few sections of this calcified formation, there was a major accumulation of low cuboidal odontoblasts.The formation of a pulp stone in the rat incisor is rare and its appearance permits the following observations. If the pulp stone can develop only when eruption has stopped, are the conditions for its formation created by the "aging" pulp or the diminishing pulpal chamber? Sayegh and Reed (Oral Surg 25: [878][879][880][881][882] 1968) maintain that calcification in the pulp increases with age. Thus, changes in the aging pulp may be the factor that promotes formation of the stones. On the other hand, Sundel, Stanley, and White (Oral Surg 25:579-589, 1968) consider disorders of circulation and hyalinization of damaged cells a predisposition for formation of pulp stones.Both factors may play a part in the rat incisor when eruption is stopped. Aging of pulp occurs when movement of cell elements of the pulp is eliminated, and development without movement of cell elements results in formation of dentin that gradually reduces the pulpal chamber. Thus, pressure is exerted on the pulp. Moreover, the folding of the dentin wall on the enamel side may render the circulation of blood more difficult and thus interfere with metabolic processes. Both these changes as a result of arrested eruption cause degenerative changes in the pulp, and thus formation of pulp stone. This also is suggested by histological observations, in particular, the finding of cell remnants Additional information available on request to authors.Pulp stone in section of rat incisor.in the nucleus and lymphocytes in the periphery.The structure of the detected pulp stone confirms the view of Johnson and Bevelander (J Dent Res 35:714-722, 1956) that pulp stones begin as false stones and later their peripheral odontoblasts form a layer of tubular dentin. If the presence of a calcified formation can stimulate fibroblasts of the pulp to differentiate in the odontoblasts, it remains unexplained why there is an unevenly thick layer of predentin on the surface of the pulp stone and why the density of cells resembling odontoblasts is different. It is possible that the different intensity of biochemical ...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.