Department of Conservative Dentistry and Endodontics, Mamata Dental College, Andhra Pradesh, India.
J Endod. 2011 May;37(5):697-700. doi: 10.1016/j.joen.2011.02.014.
Successful endodontic treatment depends on achievement of a fluid-tight seal that is not possible solely with gutta-percha and requires the use of a root canal sealer. Eugenol, which is a principal component in zinc oxide-eugenol (ZOE) based sealers, is reported to produce a volumetric expansion of gutta-percha. The aim of this study was to evaluate the three-dimensional expansion of gutta-percha at various powder/liquid ratios of ZOE-based sealer by using spiral computed tomography (SCT).
Fifty freshly extracted premolars with single canal were decoronated and instrumented by using RaCe rotary instruments (35/06). The teeth were divided into 5 groups of 10 each, and volume of the canal was measured by using SCT. The teeth were then obturated with gutta-percha cones (35/04) in groups ZE 1:1 to ZE 1:4 with Pulp Canal Sealer EWT (ZOE-based) with powder/liquid ratio of 1:1, 1:2, 1:3, and 1:4, respectively, and gutta-percha alone in control group (no sealer group). The filled volume in each canal was measured by using SCT 1 day, 7 days, and 1 month after obturation, and percentages of obturated volume and of volume changes in groups over time were calculated. The data were statistically analyzed by using one-way analysis of variance and post hoc multiple comparison tests.
The groups ZE 1:2 and ZE 1:3 gave the highest mean volume values during a 1-month period and were significantly different in comparison with groups ZE 1:1 and ZE 1:4 (P < .05).
Increasing the ratio of eugenol in sealer resulted in volumetric increase of gutta-percha. However, further studies should be performed to confirm the expansion and sealing ability of gutta-percha of the size corresponding to the prepared canal, leading to the achievement of fluid impervious seal.
成功的根管治疗取决于实现紧密的密封，而仅使用牙胶是不可能的，需要使用根管封闭剂。丁香酚是氧化锌丁香酚（ZOE）基封闭剂的主要成分，据报道，它会使牙胶产生体积膨胀。本研究的目的是通过螺旋 CT（SCT）评估不同比例 ZOE 基封闭剂的牙胶三维膨胀。
50 颗具有单根管的新鲜前磨牙经冠部切除和 RaCe 旋转器械（35/06）根管预备后，使用 SCT 测量根管容积。将牙齿分为 5 组，每组 10 颗，每组分别用 ZOE 1:1 至 ZOE 1:4（粉液比分别为 1:1、1:2、1:3 和 1:4）的 Pulp Canal Sealer EWT（ZOE 基）和单独的牙胶（无封闭剂组）进行充填。在充填后第 1、7 和 1 个月，使用 SCT 测量每个根管的填充体积，并计算每个组随时间的填充体积百分比和体积变化百分比。采用单因素方差分析和事后多重比较检验对数据进行统计学分析。
在 1 个月的时间内，ZE1:2 和 ZE1:3 组的平均体积值最高，与 ZE1:1 和 ZE1:4 组相比差异有统计学意义（P <.05）。
增加封闭剂中丁香酚的比例会导致牙胶的体积增加。然而，应该进行进一步的研究来确认与预备根管尺寸相对应的牙胶的膨胀和密封能力，以实现流体不可渗透的密封。
