Schroeder H E, Krey G, Preisig E
Abteilung für Orale Strukturbiologie, Universität Zürich.
Schweiz Monatsschr Zahnmed. 1990;100(12):1450-61.
A total of 55 extracted, vital human teeth (i.e. central and lateral incisors of the maxillary [n = 17] and the mandibular [n = 38]jaws) of patients between 40 and 97 years of age has been used to study the age-related restriction of the pulp chamber, in particular the root canal, and the structure of the inorganic dentinal wall of the pulp chamber by means of X rays and scanning electron microscopy. In addition, the density of the openings of the dentinal tubules was, under standardized conditions, determined at the coronal pulp chamber, in the middle of the root canal and apically on each of the four aspects of the pulp chamber, i.e. vestibular, mesial, oral and distal. The results demonstrated that the pulp chamber, in particular the root canal, with increasing age of the patient becomes restricted in the mesio-distal, but not or much later in the vestibulo-oral direction. This is because a network of tubule-free fibrodentin or more regular secondary dentin with or without tubules is deposited at these pulp chamber walls. The density of the tubules was at vestibular and oral aspects of the dentinal walls and also in upper incisors higher than at mesial and distal walls and in lower incisors. It also decreased mainly from the middle of the root canal towards the apex. However, because of the very heterogeneous structures at the pulp chamber walls, the tubule density was enormously variable.
共有55颗从40至97岁患者口中拔除的健康恒牙（即上颌的中切牙和侧切牙[n = 17]以及下颌的中切牙和侧切牙[n = 38]）被用于通过X射线和扫描电子显微镜研究牙髓腔（尤其是根管）与年龄相关的狭窄情况以及牙髓腔无机牙本质壁的结构。此外，在标准化条件下，测定了牙本质小管开口在冠部牙髓腔、根管中部以及牙髓腔四个面（即前庭面、近中面、口腔面和远中面）根尖处的密度。结果表明，随着患者年龄的增长，牙髓腔尤其是根管在近远中方向上变窄，但在前庭 - 口腔方向上变窄不明显或更晚才变窄。这是因为在这些牙髓腔壁上沉积了无小管的纤维牙本质网络或有或无小管的更规则的继发性牙本质。牙本质壁的前庭面和口腔面以及上颌切牙的牙本质小管密度高于近中面和远中面以及下颌切牙。牙本质小管密度也主要从根管中部向根尖方向降低。然而，由于牙髓腔壁结构非常不均一，牙本质小管密度变化极大。
