Abstract
The diffusion of microbial growth factors through extracted teeth was measured by bioassay. It was found that L-tryptophane, niacin, pantothenate and folic acid diffused from the pulp sides to the crown sides of teeth at a constant measurable rate. Diffusion through drilled teeth was from 6-23 times greater than intact teeth. Each growth factor diffused at approximately the same rate whether alone or in combination[long dash]except for folic acid in intact teeth. Significant differences were observed between diffusion ratios of the four growth factors and between individual drilled teeth. These differences appeared to be correlated with the depth of dentin through which the diffusion was occurring.