Department of Occlusion, Fixed Prosthodontics and Dental Materials, School of Dentistry, Federal University of Uberlândia, Uberlândia, MG, Brazil.
Braz Oral Res. 2012 Jul-Aug;26(4):378-83. doi: 10.1590/s1806-83242012000400016.
The core finishing of cast posts-and-cores after luting is routine in dental practice. However, the effects of the vibrations produced by the rotary cutting instruments over the luting cements are not well-documented. This study evaluated the influence of the time intervals that elapsed between the cementation and the core-finishing procedures on the tensile strength of cast posts-and-cores luted with zinc phosphate cement. Forty-eight bovine incisor roots were selected, endodontically treated, and divided into four groups (n = 12): GA, control (without finishing); GB, GC, and GD, subjected to finishing at 20 minutes, 60 minutes, and 24 hours after cementation, respectively. Root canals were molded, and the resin patterns were cast in copper-aluminum alloy. Cast posts-and-cores were luted with zinc phosphate cement, and the core-finishing procedures were applied according to the groups. The tensile tests were performed at a crosshead speed of 0.5 mm/min for all groups, 24 hours after the core-finishing procedures. The data were subjected to one-way analysis of variance (ANOVA) and Tukey's test (α = 0.05). No significant differences were observed in the tensile strengths between the control and experimental groups, regardless of the time interval that elapsed between the luting and finishing steps. Within the limitations of the present study, it was demonstrated that the core-finishing procedures and time intervals that elapsed after luting did not appear to affect the retention of cast posts-and-cores when zinc phosphate cement was used.
铸造桩核粘固后进行核心打磨是口腔修复中的常规操作。然而，旋转切割器械在粘固剂上产生的振动对粘固剂的影响尚未得到充分记录。本研究评估了在粘固后不同时间间隔进行核心打磨对玻璃离子水门汀粘固铸造桩核的拉伸强度的影响。选择 48 颗牛切牙，进行根管治疗，随机分为 4 组（每组 12 颗）：GA，对照组（不打磨）；GB、GC 和 GD 组分别在粘固后 20 分钟、60 分钟和 24 小时进行打磨。根管成型后，用铜铝合金铸造树脂模型。用玻璃离子水门汀粘固铸造桩核，根据分组进行核心打磨。所有组在打磨后 24 小时以 0.5mm/min 的十字头速度进行拉伸测试。对所有组的数据进行单因素方差分析（ANOVA）和 Tukey 检验（α=0.05）。无论粘固和打磨步骤之间的时间间隔如何，对照组和实验组的拉伸强度均无显著差异。在本研究的限制范围内，当使用玻璃离子水门汀时，核心打磨程序和粘固后经过的时间间隔似乎不会影响铸造桩核的固位力。
