Lawley G Robert, Schindler William G, Walker William A, Kolodrubetz David
Department of Endodontics, Wilford Hall Medical Center, Lackland AFB, Texas, USA.
J Endod. 2004 Mar;30(3):167-72. doi: 10.1097/00004770-200403000-00010.
The purpose of this study was to evaluate whether intracoronal delivery of an apical barrier of mineral trioxide aggregate (MTA) placed ultrasonically, non-ultrasonically, or ultrasonically with the addition of an intracanal composite resin provided a better seal against bacterial leakage. A second purpose was to determine whether intracanal composite resin or gutta-percha and sealer placed against an apical barrier of MTA provided greater resistance to root fracture. In a standardized in vitro open apex model, MTA was placed as an apical barrier at a thickness of 4 mm, with and without ultrasonic vibration. The barriers were challenged with bacteria exposure within a leakage model, and fracture resistance was assessed with increasing forces applied via an Instron machine. After 45 days, the addition of ultrasonics significantly improved the MTA seal, compared with the non-ultrasonics treatment (Kruskal Wallis nonparametric ANOVA with Dunn multiple comparison test p < 0.05). Bacterial leakage occurred in 6 (33%) of 18 in the non-ultrasonic MTA group, 2 (11%) of 18 in the ultrasonic MTA group, and 1 (6%) of 18 in the ultrasonic MTA-composite group. There were no significant differences at 90 days. A 4-mm thickness of MTA followed with an intracanal composite resin demonstrated a significantly greater resistance to root fracture than MTA followed with gutta-percha and sealer (one-way ANOVA with Newman-Keuls multiple comparison test, p < 0.01). The MTA-gutta-percha group was not significantly different than the MTA unrestored positive control.
本研究的目的是评估超声放置、非超声放置或超声放置并添加根管内复合树脂的三氧化矿物凝聚体（MTA）根尖屏障在防止细菌渗漏方面是否能提供更好的封闭效果。第二个目的是确定根管内复合树脂或牙胶与密封剂相对于MTA根尖屏障放置时，哪一种对牙根折断具有更大的抵抗力。在标准化的体外开放根尖模型中，分别在有和没有超声振动的情况下，将MTA作为根尖屏障放置，厚度为4毫米。在渗漏模型中对屏障进行细菌暴露挑战，并通过Instron机器施加递增力来评估抗折断性。45天后，与非超声处理相比，添加超声显著改善了MTA的封闭效果（Kruskal Wallis非参数方差分析与Dunn多重比较检验，p < 0.05）。非超声MTA组18个中有6个（33%）发生细菌渗漏，超声MTA组18个中有2个（11%），超声MTA - 复合组18个中有1个（6%）。90天时无显著差异。4毫米厚的MTA随后使用根管内复合树脂显示出比MTA随后使用牙胶和密封剂对牙根折断的抵抗力显著更强（单因素方差分析与Newman - Keuls多重比较检验，p < 0.01）。MTA - 牙胶组与未修复的MTA阳性对照组无显著差异。
