Variations in same-size endodontic files

Variations in same-size endodontic files (K-type, style B, stainless steel) were detected with a three-dimensional gauge. The variation between same-size files was within 3 mm. in most instances; however, variations from the smallest file in one size group to the largest file in the next size group was 5 mm. or more in many instances. Overall, about 74 percent of the variations came from the file itself. Suggestions concerning the use of the files are presented.