Dentino-pulpal collagen and the incorporation of 3H-proline by sound and carious human teeth in vitro.

In vitro incorporation of proline by odontoblasts and pulpal cells of human carious and non-carious teeth was compared. The types of collagen in predentine and pulpal matrices of carious as well as intact teeth were characterized electrophoretically. The results indicate increased incorporation in the caries-affected odontoblast-predentine layer, with no quantitative changes in the adjacent pulp tissue. The predentine matrix of both intact and carious teeth showed an electrophoretic banding typical to type I collagen. The pulpal matrix, regardless of the state of the tooth, displayed a mixture of collagen types I and III, the former being clearly predominant. It seems that a carious process in dentine increases the collagen forming activity in the adjacent odontoblasts, but does not affect the quality or alter the relative proportion of the collagen types I and III.