Canalda-Sahli C, Brau-Aguadé E, Sentís-Vilalta J
Department of Dental Pathology and Therapeutics, Faculty of Dentistry, University of Barcelona, Spain.
Int Endod J. 1998 Jan;31(1):48-52.
The purpose of this study was to assess the effect of dry-heat or autoclave sterilization on the resistance to fracture in torque and angular deflection and the resistance to bending of K-type files made of nickel-titanium (Nitiflex, Naviflex), titanium (Microtitane) or stainless steel (Flexofile, Flex-R). Ten K-type files of each sort, from size 25 to 40, were tested, according to ANSI/ADA specification 28 (1988) and ISO specification 3630 (1992). Sterilization with dry heat and autoclave slightly decreased the flexibility of files made of stainless steel and nickel-titanium for most of the sizes, although the values obtained satisfied ISO specifications. The files made of titanium showed an increased flexibility after sterilization with autoclave (sizes 30 and 35) and dry heat (sizes 30, 35 and 40). Resistance to fracture varied amongst the five groups of files tested as follows: it decreased in some sizes of stainless-steel instruments, decreased in all sizes of titanium files assessed by the torsional moment, and either increased or decreased in some sizes of nickel-titanium files. All files tested, however, satisfied relevant standards for angular deflection after being subjected to sterilization with an autoclave or dry heat.
本研究的目的是评估干热或高压蒸汽灭菌对由镍钛合金（Nitiflex、Naviflex）、钛（Microtitane）或不锈钢（Flexofile、Flex-R）制成的K型锉在扭矩和角度偏转方面的抗折断性以及抗弯性的影响。根据美国国家标准学会/美国牙科协会规范28（1988年）和国际标准化组织规范3630（1992年），对每种类型从25号到40号的10根K型锉进行了测试。对于大多数尺寸，干热和高压蒸汽灭菌会略微降低不锈钢和镍钛合金制成的锉的柔韧性，不过所获得的值符合国际标准化组织规范。用高压蒸汽灭菌（30号和35号尺寸）和干热灭菌（30号、35号和40号尺寸）后，钛制成的锉柔韧性增加。在测试的五组锉中，抗折断性变化如下：一些尺寸的不锈钢器械抗折断性降低，通过扭矩评估的所有尺寸的钛锉抗折断性降低，一些尺寸的镍钛合金锉抗折断性要么增加要么降低。然而，所有测试的锉在经过高压蒸汽或干热灭菌后，角度偏转均符合相关标准。
