Cytotoxicity test of dentin bonding agents using millipore filters as dentin substitutes in a dentin barrier test

Objectives The purpose of this study was to find proper dentin substitute for standardized dentin barrier test and perform the cytotoxicity test of commercial bonding agents with the proper substitute. Materials and methods The three-dimensional cells attached to dentin disc or millipore filters as the dentin substitute were tested in a dentin barrier test by perfusion. MTT assay was performed as an evaluation method for the cell survival rate. The cytotoxicity test of serial phenol dilution by bovine dentin disc was done to determine a standard toxic material, and the test of this proper phenol by using various millipore combinations was performed to find the suitable dentin substitute. Also, the cytotoxicity test of bonding agents was performed by this standardized substitute. The cell viability was expressed as percentages of untreated group. Results Phenol concentration of 0.05 % was selected as the standard toxic material. The different combinations of millipore filters—two sheets of 0.45 μm, two sheets of 0.22 μm, and the combination of 0.65, 0.45, and 0.22 μm—showed similar cytotoxicity to natural dentin discs by 0.05 % phenol ( p > 0.05). The millipore combination of 0.65, 0.45, and 0.22 μm that had structural similarity to natural dentin discs was used as the substitute for cytotoxicity test of bonding agents. The toxic level of Adper Prompt L-Pop using the selected substitute was significantly the highest among four kinds of dentin bonding agents ( p