1990 Volume 11 Issue 2 Pages 183-191
The standard type reamers and gutta percha points on the market were measured according to the ISO standard and the conclusion reached as follows.
1. The endodontic comparison gauge of each company was inaccurate in size, compared with the standard.
2. As to the measurement of reamers, most of reamers' points d1 were within the tolerance and remarkably deviated as their size goes larger. Most of d2 were out of the tolerance at the size of high utilization and the number of inaccurate size increased according as the size becomes larger.
3. As to the measurement of gutta percha points, the tips d1 of points of the two companies were within the tolerance but that of the two other companies were out of the tolerance. Most of d2 were the lower limit of the tolerance at the size of highly frequent use and the number of inaccurate size increased according as the size becomes larger.
4. It is necessary to maintain accuracy of the reamers as the present state and especially to make d2 more accuracy.
5. It is necessary to enlarge the extent of tolerance and also to revise the standard of points' size.
