2018 Volume 61 Issue 1 Pages 40-47
Purpose: The purpose of this study was to compare the total preparation time, the amount of canal transportation and the pushing and pulling forces of the following four files: the single Ni-Ti file system (RECIPROC: RE), multi Ni-Ti files system (Twisted File: TF and ProTaper: PT) and stainless steel multi-file system (K-file: SSK).
Methods: Thirty-six transparent resin models which had curved root canals of 30 degrees were used (n=9, each). Photographs taken before and after preparation of the canal were superimposed. The amounts of canal transportation were measured at 1-mm intervals from the apical foramen to the 9 mm level. The total preparation time, and the forces required for push load and pull-out load during root canal preparation were measured. The data were analyzed by Games-Howell’s method after one-way ANOVA.
Results: The total preparation time was short in the order of TF, RE, PT and SSK and significant differences were observed between each group. There was no significant difference in the amount of canal transportation between all groups at 0 and 1 mm from the apex. At 2 and 3 mm, significant differences were observed between RE and TF, PT, and also SSK and TF, PT. At 4 mm, significant differences were observed between RE and TF, PT, and also SSK and TF, PT, in addition to TF and PT. At 5 mm, significant differences were observed between RE and TF, PT. At 6 mm, significant differences were observed between RE and other groups, and also SSK and other groups. At 7 mm, significant differences were observed between SSK and other groups, and also TF and PT. At 8 and 9 mm, significant differences were observed between SSK and other groups. The pushing and pulling forces were greatest in SSK and were smaller in the order of RE, PT and TF. The pushing forces indicated significant differences between all groups, however, the pulling forces showed no significant difference between TF and PT.
Conclusion: The single-file system using RECIPROC has higher shaping ability than the multi-file system, however, the inner side of the apical area was removed in the curved canals, suggesting that the prevention of strip perforation is needed when using RECIPROC.
