Transdentinal stimulation of tertiary dentine formation and intratubular mineralization by growth factors

To evaluate the effects of recombinant growth factors on tertiary dentine formation and intratubular mineralization after their application on deep dentinal cavities in dog's teeth.

Treatment included dentinal etching (37% phosphoric acid) and applications of bioactive molecules (1 microg mL(-1) TGF-beta1, 10 microg mL(-1) IGF-1, 10 microg mL(-1) bFGF, 10 microg mL(-1) OP-1 or 1 microg mL(-1) monoclonal anti-human TGF-beta1 in phosphate buffered saline, PBS) at the dentinal base of buccal Class V cavities. Control groups were treated with 0.1% dog serum albumin (DSA) in PBS omitting the growth factors. This was performed both with and without dentinal etching. The dentinal responses regarding tertiary dentine formation and intratubular mineralization were assessed after 3 and 8 weeks, respectively, using light and scanning electron microscopy. Some specimens were also subjected to dentine permeability testing.

The group treated with transforming growth factor-beta1 (TGF-beta1) and, to a lesser extent, the one treated with osteogenic protein-1 (OP-1) showed significantly greater (P < 0.05) tertiary dentine formation and intratubular mineralization over an 8-week period when compared with the control and the other experimental groups. There were no significant differences between groups in reduction in dentine permeability after treatment.

Treatment of exposed dentinal tubules with biologically active molecules might induce intratubular mineralization and tertiary dentine formation. Further research is needed to substantiate any clinical benefits as opposed to traditional treatments of exposed dentine so as to provide a scientific base for the clinical regulation of dentine reactions.