各種Reamer, Fileの走査型電子顕微鏡所見

抄録

  In order to be able to systematically carry out root canal treatment, the instruments and guttapercha-points used for treatment should be arranged based on the angle of the angle of the tip and taper regulated by the International Standardized Organization (ISO). But in reality, standardization of root canal instruments and guttapercha-points is difficult. Variations from the standard requirements can be observed between different manufacturers and even within a manufacturer. For the purpose of comfirming the above mentioned problems, we examined several files and reamers manufactured by six different manufactures (MANI, GC, Kerr etc) under the SEM.

  The tip and edges of each instrument were examined in detail before and after its use. As a result, four out of the thirty-six unused instruments were found not to be proper for the ISO. All H-files, however, were found to meet the acceptable standard requirements. We were also able to observe a variety of morphological changes on the tip and edges of used instruments. Especially when these instruments were used in strongly curved canals, the changes observed on the tip or edges in these instruments were severe and irreparable. Form the above findings, one must realize the importance of a careful and meticulous examination of every file and reamer prior its insertion in root canal, and this is especially critical when reusing old instruments.