Department of Dentistry, Dental School, State University of Montes Claros, Montes Claros, MG, Brazil.
J Appl Oral Sci. 2010 Sep-Oct;18(5):528-32. doi: 10.1590/s1678-77572010000500017.
The aim of this study was to evaluate the effect of simulated periodontal ligament (SPDL) on custom cast dowel and core removal by ultrasonic vibration.
Thirty-two human maxillary canines were included in resin cylinders with or without SPDL made from polyether impression material. In order to allow tensile testing, the roots included in resin cylinders with SPDL were fixed to cylinders with two stainless steel wires. Post-holes were prepared by standardizing the length at 8 mm and root canal impressions were made with self-cured resin acrylic. Cast dowel and core sets were fabricated and luted with Panavia F resin cement. Half of the samples were submitted to ultrasonic vibration before the tensile test. Data were analyzed statistically by two-way ANOVA and Tukey's post-hoc tests (p<0.05).
The ultrasonic vibration reduced the tensile strength of the samples directly included in resin cylinders. There was no difference between the values, whether or not ultrasonic vibration was used, when the PDL was simulated. However, the presence of SPDL affected the tensile strength values even when no ultrasonic vibration was applied.
Simulation of PDL has an effect on both ultrasonic vibration and tensile testing.
本研究旨在评估模拟牙周膜（SPDL）对超声振动下定制铸造桩核去除的影响。
将 32 个人上颌尖牙分别包含在有或没有聚醚印模材料制成的 SPDL 的树脂圆柱体中。为了允许进行拉伸试验，包含 SPDL 的树脂圆柱体中的牙根用两根不锈钢丝固定到圆柱体上。通过标准化长度至 8mm 来制备桩道，并使用自固化树脂丙烯酸制作根管印模。制作铸造桩核并使用 Panavia F 树脂水门汀黏结。在进行拉伸试验之前，将一半的样本进行超声振动。通过双向方差分析和 Tukey 的事后检验（p<0.05）对数据进行统计学分析。
超声振动降低了直接包含在树脂圆柱体中的样本的拉伸强度。无论是否使用超声振动，模拟 PDLS 时，其值之间没有差异。然而，即使未施加超声振动，SPDL 的存在也会影响拉伸强度值。
PDL 的模拟对超声振动和拉伸测试都有影响。
