AN IN-VITRO MODEL OF HUMAN DENTAL-PULP REPAIR

Pulp tissue responds to dentin injury by laying down reactionary denti n secreted by existing odontoblasts or reparative dentin elaborated by odontoblast-like cells that differentiated from precursor cells in th e absence of inner dental epithelium and basement membrane. Furthermor e, growth factors or active dentin matrix components are fundamental s ignals involved in odontoblast differentiation. In vitro, dental pulp cells cultured under Various conditions are able to express typical ma rkers of differentiation, but no culture system can re-create pulp res ponse to dentin drilling. This gaper reports the behavior of thick sli ces from human teeth drilled immediately after extraction and cultured from 3 days to 1 month. Results show that the damaged pulp beneath th e cavity is able to develop, in vitro, some typical aspects correlated to tissue healing, evidenced by cell proliferation (BrdU-positive cel ls), neovascularization (positive with anti-type-IV collagen antibodie s), and the presence of functional (H-3 proline-positive) cuboidal cel ls close to the injured area. After 30 days of culture, elongated spin dle-shaped cells can be seen aligned along the edges of the relevant d entin walls, whereas sound functional odontoblasts are well-preserved beneath healthy areas. This tissue recovery leads us to believe that s uch a culture model will be a useful system for testing factors regula ting pulp repair.