DOH100 Lecture Notes - Lecture 5: Ground Substance, Basal Lamina, Cementum
Document Summary
Serum calcium ions taken up by odontoblasts and accumulates in distal body. Under control of dpp, calcium ions deposited onto a template formed by collagen i fibrils to build up as crystalline mineral. Found that dpp is absent in a condition called dentinogenesis imperfecta (defected hypomineralised dentine thus dpp important) Location of nucleation to specific regions of collagen fibril surface. Limited to mantle dentine (very thin layer just underneath enamel, first formed) Still dpp mediated mineralisation but also matrix vesicle which is only here. Cell budding which is the fragmentation to form matrix vesicles occurs in what will become mantle dentine. Formation of cell membrane bound organelles (30-200 nm) odontoblastic cell buds organelles that are bound by membranes unlike dpp here there are vesicles that form and travel to predentine area. Leads to concentration of phosphate ions and thus development of mineral crystals within the vesicles. Crystals initiate mineralisation (all inside the membrane bound organelles)
