Department of Conservative Dentistry and Endodontics, Pacific Dental College and Hospital, Udaipur, Rajasthan, 313024, India.
Department of Endodontics, Faculty of Dentistry, Istanbul Health Sciences University, Istanbul, Turkey.
Clin Oral Investig. 2021 Apr;25(4):1989-1995. doi: 10.1007/s00784-020-03507-x. Epub 2020 Aug 10.
(1) To evaluate the effectiveness of the static-guided (SG) endodontics technique for accessing the root canal through the mineral trioxide aggregate (MTA) and (2) to evaluate the effect of this technique on the fracture strength of teeth.
Thirty mandibular premolars were used in the present study. After standard coronal access cavity preparation, root canals were prepared up to size #80 to simulate an immature root apex. White MTA was placed approximately 3 mm below the cementoenamel junction (CEJ), as placed in regenerative endodontic procedures. After the MTA had set, the cavity was restored with a resin composite material. The teeth were randomly divided into two groups (n = 15). In the control group, the composite resin and MTA were removed without any guide. In the SG-access group, a cone beam computed tomography (CBCT) scan was performed, 3D-printed guides were designed and fabricated, and then the composite resin and MTA were removed with a guide. One inexperienced operator performed the removal of the composite resin and MTA in all groups. Pre- and post-operative periapical radiographs were taken. The mishaps and time to penetration to root canal were recorded. After that, the root canals were filled, and the access cavities were restored. The samples were subjected to a fracture strength test. Data were analyzed using Mann-Whitney U, independent samples of T test, and chi-square tests at 95% confidence level (P = 0.05).
There were significant differences between the control and SG-access groups in terms of mishaps and time to penetration to the root canal through the MTA barrier (P < 0.05). The SG-access group required the shorter time as compared with the control group. Mishaps did not occur in the SG-access group. The SG-access group exhibited the significantly preserved fracture resistance of the teeth as compared with the control group (P < 0.05). Non-restorable failure occurred more frequently in the control group than in the SG-access group.
Within the limitations of the present study, the SG endodontic technique yielded favorable results with respect to time, mishaps, and fracture strength.
The static-guided endodontics technique may provide advantages to the clinician for MTA removal.
（1）评估静态引导（SG）牙髓技术通过矿化三氧化物凝聚体（MTA）进入根管的有效性，以及（2）评估该技术对牙齿断裂强度的影响。
本研究使用 30 颗下颌前磨牙。在标准的冠向入口腔制备后，根管被制备至 #80 号大小，模拟未成熟根尖。白色 MTA 放置在牙骨质牙釉质交界处（CEJ）下方约 3 毫米处，如再生牙髓治疗中放置。MTA 凝固后，用树脂复合材料修复窝洞。牙齿被随机分为两组（n = 15）。在对照组中，不使用任何引导物去除复合树脂和 MTA。在 SG 进入组中，进行锥形束计算机断层扫描（CBCT）扫描，设计和制作 3D 打印引导物，然后使用引导物去除复合树脂和 MTA。所有组均由一名无经验的操作员进行复合树脂和 MTA 的去除。术前和术后根尖片拍摄。记录意外事件和穿透到根管的时间。之后，根管填充，修复入口腔。对样本进行断裂强度测试。使用 Mann-Whitney U 检验、独立样本 t 检验和卡方检验（置信水平为 95%，P = 0.05）进行数据分析。
在意外事件和穿透 MTA 屏障进入根管的时间方面，对照组和 SG 进入组之间存在显著差异（P < 0.05）。SG 进入组比对照组所需时间更短。SG 进入组未发生意外事件。SG 进入组的牙齿断裂阻力明显优于对照组（P < 0.05）。对照组的不可修复性失败发生率高于 SG 进入组。
在本研究的限制范围内，SG 牙髓技术在时间、意外事件和断裂强度方面取得了良好的效果。
静态引导牙髓技术可能为医生提供在去除 MTA 方面的优势。
