Nano Biomedicine

An Attempt on the Cell Survival and Cell Differentiation by Fine Fragments of Tungsten Carbide and Steel Cutting Bars

Koichi IMAI1, Tsubasa SHIRAI1, Masayuki ZENNYU1, Takamitsu YOSHIDA1, and Tetsunari NISHIKAWA2

1Department of Biomaterials, 2Department of Innovation in Dental Education,
Osaka Dental University, Osaka, Japan

Nano Biomed 2017;9(1):3-8, (Jun 30, Nano Biomedicine)

Tungsten carbide and steel bar are used intraorally for the removal of dental prostheses and for cutting teeth. Blades at the tip of the bar can often chip, leaving small fragments of blades inside onefs mouth. Such small fragments of blades can remain inside the mouth even after rinsing, and can penetrate the soft intraoral tissues. To assess the safety of the small fragments of cutting bar in the human body, we used a tissue model made of 3D collagen gel to examine their cytotoxicity. Furthermore, these small fragments may be transported through the vascular system and induce developmental toxicity. Therefore, we examined their influence on cell differentiation using ES-D3 cells. Our results demonstrated that while steel bar exhibited little cytotoxicity, tungsten carbide cutting bar showed no cytotoxicity. However, both cutting bar reduced the differentiation of ES-D3 cells, indicating that the sharp edges of the fragments of blades can inhibit cell differentiation. Further studies are needed to investigate the influence of the shapes of cutting bar fragments on cell differentiation.

Key words: tungsten carbide bar, steel bar, cytotoxicity, differentiation, ES-D3 cells

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