Analysis of histologic criteria commonly used in pulp studies

A total of 359 rhesus monkey teeth and 187 human teeth were studied histologically after cavity preparation and restoration with various materials. It was found that human and monkey teeth do not correlate in all of the established criteria for evaluation of pulp responses. For correlation to be valid, the depth of remaining dentin in monkey teeth should be less than 1.0 mm. Cellular displacement would be considered to be significant only if the monkey teeth are extracted surgically. Both superficial and deep responses can be correlated directly, but the degree of hemorrhage is not significant in evaluating monkey teeth. Although reparative dentin can be correlated, it is formed sooner and in greater amounts in monkey than in human teeth.