Williams Chad, Loushine Robert J, Weller R Norman, Pashley David H, Tay Franklin R
Department of Endodontics, School of Dentistry, Medical College of Georgia, Augusta, Georgia 30912-1244, USA.
J Endod. 2006 Jun;32(6):553-5. doi: 10.1016/j.joen.2005.08.002. Epub 2006 Apr 4.
The purpose of this study was to compare the cohesive strength and stiffness of Resilon and gutta-percha under dry conditions and after 1 month of water storage to determine if they are stiff enough to reinforce roots. Dog-bone shaped specimens were created and pulled to failure at 3 mm/min in a Vitrodyne universal tester. The apparent modulus of elasticity, percent elongation, and yield stress were measured. Cohesive strength was defined as the yield stress. The data were analyzed using a two-way ANOVA for each outcome (alpha = 0.05). The results of this study show that the cohesive strength (that is the tensile stress when they begin to flow or break) and modulus of elasticity (or stiffness) of gutta-percha and Resilon are relatively low. Although the results showed statistically significant differences between the physical properties of gutta-percha and Resilon under varied conditions, these differences were not clinically significant. In conclusion, the stiffness of Resilon and gutta-percha is too low to reinforce roots after root canal therapy.
本研究的目的是比较Resilon和牙胶在干燥条件下以及水储存1个月后的内聚强度和刚度，以确定它们是否足够坚硬来增强牙根。制作了狗骨形标本，并在Vitrodyne万能试验机中以3毫米/分钟的速度拉伸至破坏。测量了表观弹性模量、伸长率百分比和屈服应力。内聚强度定义为屈服应力。对每个结果使用双向方差分析（α = 0.05）对数据进行分析。本研究结果表明，牙胶和Resilon的内聚强度（即它们开始流动或断裂时的拉伸应力）和弹性模量（或刚度）相对较低。尽管结果显示在不同条件下牙胶和Resilon的物理性质之间存在统计学上的显著差异，但这些差异在临床上并不显著。总之，Resilon和牙胶的刚度太低，无法在根管治疗后增强牙根。
