Evaluation of Millipore Filters as Dentin-substitutions in Dentin Barrier Test

Objectives: The aim of this study was to compare experimental results of dentin barrier test by dentin-substitutions to those by bovine dentin discs. Methods: Millipore filters (Millipore, Ireland) with 0.80-0.05 ㎛ of pore size were used as dentin-substitutions. Polyamide mesh (Sefar Medifab®, USA) was used for simulating 3-D cell culture. Human osteoblast-like MG 63 cells were seeded on the mesh that was combined with milipore filters or bovine dentin disc (500 ㎛ thickness) and cultured for 14 days in growth media. Control group had only 3-D culturing cells without any test material. 1.00, 0.10 and 0.05% of phenol were placed on the cavity side (upper part of dentin discs or substitutions) of the experimental groups. Cytotoxicity tests were performed for 24 hours using perfusion culture system (Minucells & Minutissue GmbH, Bad abbach, Germany) which was a media-flowing appliance. Results of the experimental groups were expressed as percentages compared to the control using MTT assay. Statistical analyses among groups were performed applying the nonparametric Mann-Whitney U test(P>.05). Results: 1.00, 0.10 and 0.05% of phenol made 9.00, 20.67, 60.50% of cell viability in bovine teeth, respectively. 0.45 and 0.22 ㎛ groups with 0.05% of phenol showed that the more overlapped filters resulted the less cell viability (P<.05). And cell viabilities of followings using milipore filters were not statistically different with the natural bovine discs (P>.05): 2 sheets of 0.45 ㎛, 1 sheet of 0.05 ㎛ and 0.80+0.65+0.45 ㎛. Conclusions: Among three different phenol groups, 0.05% revealed suitable cell viability as a test material. 2 sheets of 0.45 ㎛, 1 sheet of 0.05 ㎛ and 0.80+0.65+0.45 ㎛ had similar characteristics to the natural bovine dentin discs as dentin-substitutions according to this study. Acknowledgement: This work was supported by Medical Science and Engineering Research Center (No. 7-2010-0535) from the Ministry of Education, Science Technology.