3H proline uptake in the tubular compartment of dentin in the rat molar.

With the use of conventional autoradiographic techniques, it was demonstrated that dentin captures 3H proline in significantly greater amounts (p < 0.0002) than sclerotic dentin or alveolar bone. Histological observation and the absence of capture by sclerosed dentin indicated that this capture occurs within the tubular compartment of dentin. It is suggested that this capture reflects the deposition of collagen in this compartment. An increase in 3H proline capture occurs in dentin affected by cavity preparation (p < 0.0001). This increase in capture, on the basis of electron microscopic observation, could not be linked to an increase of collagen deposition in affected tubules.