Yassa Shady Atef Adeeb, Nabeel Mohamed, Ghobashy Ahmed M, Alkhawas Moataz B
Department of Endodontics, Misr International University, Giza, Egypt.
Department of Endodontic, Al-Azhar University, Cairo, Egypt.
J Conserv Dent Endod. 2025 Apr;28(4):319-324. doi: 10.4103/JCDE.JCDE_27_25. Epub 2025 Apr 3.
Guided endodontics has been revolutionizing endodontics, emphasizing the need to further investigate its capabilities in terms of degrading separated instruments will be of great value.
The aim of this study was to compare, in vitro, the static endodontic guide and ultrasonic methods for managing separated instruments, focusing on fracture resistance, dentin changes, and procedural time.
Twenty-two extracted double-rooted maxillary first premolars were decoronated to 15 mm in length and mounted in acrylic resin blocks for standardized cone-beam computed tomography (CBCT) scanning. Size 25/0.06 rotary files were notched at 3 mm and separated in the coronal third of the buccal canals under controlled conditions. Teeth were randomly assigned into two groups ( = 11): Group G utilized static endodontic guides fabricated for instrument degradation, and Group U employed conventional ultrasonic technique for retrieval. Volumetric dentin loss, fracture resistance, and time required for retrieval were evaluated using CBCT scans, universal testing machines, and stopwatch recordings.
Normality tested; t-test for parametric, Mann-Whitney for nonparametric.
The ultrasonic group showed significantly higher fracture resistance and less root canal volume increase compared to the static endodontic guide group. However, the ultrasonic group required significantly more time for retrieval. All differences were statistically significant ( < 0.001).
The study compares ultrasonic and static endodontic guides for instrument retrieval, highlighting static endodontic guides' speeds but increased dentin loss, deeming them unsuitable for degrading instruments with burs. Further research is needed.
引导式牙髓治疗学一直在革新牙髓病学，强调有必要进一步研究其在降解分离器械方面的能力，这将具有重大价值。
本研究的目的是在体外比较静态牙髓引导法和超声法处理分离器械的效果，重点关注抗折性、牙本质变化和操作时间。
将22颗拔除的上颌第一双根前磨牙截短至15毫米长，并安装在丙烯酸树脂块中进行标准化锥形束计算机断层扫描（CBCT）。25/0.06号旋转锉在3毫米处刻痕，并在可控条件下在颊侧根管的冠三分之一处分离。牙齿随机分为两组（每组n = 11）：G组使用为器械降解制作的静态牙髓引导器，U组采用传统超声技术进行取出。使用CBCT扫描、万能试验机和秒表记录来评估牙本质体积损失、抗折性和取出所需时间。
进行正态性检验；参数检验用t检验，非参数检验用曼-惠特尼检验。
与静态牙髓引导器组相比，超声组显示出显著更高的抗折性和更小的根管体积增加。然而，超声组取出所需时间显著更长。所有差异均具有统计学意义（P < 0.001）。
本研究比较了超声法和静态牙髓引导器法取出器械的效果，突出了静态牙髓引导器的速度，但牙本质损失增加，认为它们不适用于用牙钻降解器械。需要进一步研究。
