Khedmat Sedigheh, Aghajani Farzaneh, Zaringhalam Shabnam
Dental Research Center Dentistry Research Institute, Department of Endodontics, School of Dentistry, Tehran University of Medical Sciences, and Iranian Center for Endodontic Research, Tehran, Iran.
Department of Dental Biomaterials, School of Dentistry, Dental Research Center Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
J Dent (Tehran). 2013 Nov;10(6):548-53. Epub 2013 Nov 30.
To compare the mechanical properties of Resilon and gutta-percha cones after storing at three different temperatures.
One-hundred standardized size 40/02 gutta-percha cones and 100 Resilon cones were randomly divided into four groups. The first group of the materials were tested immediately after receipt as the control group. The other three were stored in their packages at -12°C, 4± 1°C and 22± 2°C for three months. Then, obturating cones were loaded by a tensile force at the rate of 5mm/min. Physical integrity of gutta-percha and Resilon cones were also evaluated according to ISO6877. The data were analyzed by one-way analysis of variance, post hoc and t-test. A p-value <0.05 was considered significant.
The elasticity modulus of gutta-percha reduced significantly after three months storage at -12°C, while storage at 4±1°C and 22± 2°C had no effect on its modulus of elasticity. In addition, the tensile strength of gutta-percha did not change after three months of storing. The modulus of elasticity of Resilon reduced significantly in all storage conditions; however, its tensile strength did not change. The storage conditions did not have a significant effect on the elongation rate of gutta-percha and Resilon. Eighty percent of gutta-percha cones lost their physical integrity after storage in 4 °±1C and 22±2°C. However, storage conditions had no impact on the physical integrity of Resilon cones.
Storing gutta-percha at -12°C can benefit its properties, while keeping Resilon at both refrigerated and room conditions can preserve its mechanical properties.
比较Resilon和牙胶尖在三种不同温度下储存后的力学性能。
将100支标准化尺寸40/02的牙胶尖和100支Resilon根管充填尖随机分为四组。第一组材料在收到后立即进行测试作为对照组。其他三组分别在-12°C、4±1°C和22±2°C的包装中储存三个月。然后，以5mm/min的速率对充填尖施加拉伸力。还根据ISO6877评估牙胶尖和Resilon根管充填尖的物理完整性。数据采用单因素方差分析、事后检验和t检验进行分析。p值<0.05被认为具有统计学意义。
牙胶尖在-12°C储存三个月后弹性模量显著降低，而在4±1°C和22±2°C储存对其弹性模量没有影响。此外，牙胶尖储存三个月后的拉伸强度没有变化。Resilon在所有储存条件下弹性模量均显著降低，但其拉伸强度没有变化。储存条件对牙胶尖和Resilon的伸长率没有显著影响。80%的牙胶尖在4±1°C和22±2°C储存后失去了物理完整性。然而，储存条件对Resilon根管充填尖的物理完整性没有影响。
将牙胶尖储存在-12°C对其性能有益，而将Resilon保存在冷藏和室温条件下均可保持其力学性能。
