Growth kinetics of fibroblasts on bovine dentin

In vitro dentin barrier tests published so far show several shortcomings. Therefore, we designed a new test method using bovine dentin disks on which cells were grown on one side. In this study, we evaluated the growth kinetics of L-929 mouse fibroblasts on dentin disks of 0.75-mm thickness and 4-mm diameter derived from lower incisors of freshly slaughtered bovines. The application of 50% citric acid for 30 s was optimal for the gentle removal of the smear layer from the cut dentin slices. Growth kinetics of mouse fibroblasts depended on the initially plated cell density: optimal cell growth on the disks was observed with approximately 200 cells/mm2, which was the same as the growth rate on the bottom of a cell culture vessel. Consequently, bovine dentin disks are a suitable substrate for normal cell growth, and this set-up can be used in a dentin barrier test.