Dentin Mineralization and the Role of Odontoblasts in Calcium Transport

Abstract

Dentin is formed by two simultaneous processes, in which the odontoblasts are instrumental--the formation of the collagenous matrix, and mineral crystal formation in this matrix. This pattern of formation is similar to that of bone, another mineralized connective tissue. Dentin and bone also have chemical compositions which are similar but with distinct differences. It is of fundamental importance to understand how the ions constituting the inorganic phase are transported from the circulation to the site of mineral formation and how this transport is regulated. For dentinogenesis, calcium is essentially the only ion for which data are available. Recent evidence suggests that a major portion of the Ca2+ ions are transported by a transcellular route, thus being under cellular control. The cells maintain a delicate Ca2+ ion balance by the concerted action of transmembraneous transport mechanisms, including Ca-ATPase, Na+/Ca2+ exchangers and calcium channels, and of intracellular Ca(2+)-binding proteins. The net effect of this is a maintenance of a submicromolar intracellular Ca2+ activity, and an extracellular accumulation of Ca2+ ions in predentin, at the mineralization front. Predentin can be regarded as a zone of formation and maturation of the scaffolding collagen web of the dentin organic matrix. In addition to collagen, it contains little but proteoglycan. Simultaneous with mineral formation, additional non-collagenous macromolecules are added to the extracellular matrix of dentin, these presumably being transported within the odontoblast process. Among these are highly phosphorylated dentin phosphoprotein (phosphophoryn) and another pool of proteoglycan.(ABSTRACT TRUNCATED AT 250 WORDS)

Histology of dental pulp healing after tooth replantation in rats

“…[2][3][4][5][6][7][8][9] 이는, odontoblast의 주된 역할이 전상아질 및 상아질의 기질 (collagen, proteoglycans)을 생산하고, 칼슘 이온을 운반 하여 전상아질 및 상아질의 석회화를 일으키는 것이기 때문 에 나타나는 현상이다. 10) 외부 자극에 대한 반응으로 나타나는 치아의 mineralization은 주로 삼차 상아질(tertiary dentin) 형성으로 이루 어진다. 삼차 상아질의 특징은 그 구조가 매우 불규칙적이 며, 상아세관이 이차 상아질과 연속되지 않는 것이 보통이 다.…”

Mineralization process during acellular cementogenesis in rat molars: a histochemical and immunohistochemical study using fresh-frozen sections

“…The initial cementum requires a dense accumulation of BSP and OPN for its mineralization, probably due to the lack of stable mineralization media (=collagen fibrils). Once the mineralization extends to the principal fibers, the mineralization advances in the known fashion dependent on collagen fibrils (for reviews, see Limeback 1991;Linde 1995;Goldberg et al 1995;Embery et al 2001).…”

Biomimetic synthesis of poly(lactic-co-glycolic acid)/multi-walled carbon nanotubes/apatite composite membranes

“…The SEM image taken at a higher magnification in Figure 3b reveals that MWNTs which were short tubular shaped were well dispersed and embedded in PLGA matrix, indicating that good alignment of MWNTs was achieved in PLGA matrix during the preparation of the composite membranes. After 21 days of mineralization, the surfaces of the three samples were all covered by a layer of white mineralized crystals, but the mineral solutions still remained clear, indicating that heterogeneous nucleation occurred on the surfaces of the composite membranes [23,24]. As shown in SEM images presented in Figure 4, the surfaces of all the PLGA/ MWNTs composite membranes showed an obvious change after mineralization.…”