Impact of Radial Lands on the Reduction of Torque/Force Generation of a Heat-Treated Nickel-Titanium Rotary Instrument

Taro Nakatsukasa; Arata Ebihara; Moe Sandar Kyaw; Satoshi Omori; Hayate Unno; Shunsuke Kimura; Keiichiro Maki; Takashi Okiji

doi:10.3390/app12052620

Applied Sciences (Mar 2022)

Impact of Radial Lands on the Reduction of Torque/Force Generation of a Heat-Treated Nickel-Titanium Rotary Instrument

Taro Nakatsukasa,
Arata Ebihara,
Moe Sandar Kyaw,
Satoshi Omori,
Hayate Unno,
Shunsuke Kimura,
Keiichiro Maki,
Takashi Okiji

Affiliations

Taro Nakatsukasa: Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113 8549, Japan
Arata Ebihara: Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113 8549, Japan
Moe Sandar Kyaw: Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113 8549, Japan
Satoshi Omori: Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113 8549, Japan
Hayate Unno: Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113 8549, Japan
Shunsuke Kimura: Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113 8549, Japan
Keiichiro Maki: Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113 8549, Japan
Takashi Okiji: Department of Pulp Biology and Endodontics, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113 8549, Japan

DOI: https://doi.org/10.3390/app12052620
Journal volume & issue: Vol. 12, no. 5
p. 2620

Abstract

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This study investigated the impact of a one-sided radial-landed cross-sectional design of a heat-treated nickel-titanium rotary instrument (JIZAI, MANI, Japan; JZ) on torque/force generation and canal-shaping ability, using an experimental non-landed instrument (non-landed JZ) for comparison. Both instruments had tip sizes of 25 and 0.04 or 0.06 taper and were similar in metallurgy and geometry, except for the presence/absence of a radial land. Twenty J-shaped simulated resin canals were instrumented in a two-instrument single-length sequence using an automated root canal instrumentation device with a torque/force analyzing unit. Pre- and post-instrumentation images of the resin canals were analyzed for canal-centering ability at 0–3 mm from the apex. The mean centering ratio was not significantly different between JZ and non-landed JZ (p > 0.05). In the 2nd instrumentation, JZ showed a significantly smaller torque compared with the non-landed JZ (p p p < 0.05) than the non-landed JZ. JZ generated smaller screw-in forces and had similar canal-centering ability compared with the non-landed JZ.

Published in Applied Sciences

ISSN: 2076-3417 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Technology: Engineering (General). Civil engineering (General); Science: Biology (General); Science: Physics; Science: Chemistry
Website: http://www.mdpi.com/journal/applsci

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