Bugea Calogero, Berton Federico, Rapani Antonio, Di Lenarda Roberto, Perinetti Giuseppe, Pedullà Eugenio, Scarano Antonio, Stacchi Claudio
Independent Researcher, 73100 Lecce, Italy.
Department of Medical, Surgical and Health Sciences, University of Trieste, 34100 Trieste, Italy.
Bioengineering (Basel). 2022 Mar 2;9(3):103. doi: 10.3390/bioengineering9030103.
Although the application of ultrasounds in endodontic surgery allows for effective debridement of the root canal, incorrect device setting or inefficient tips seem to generate cracks during root-end retropreparation. The primary aim of this in vitro study was to establish the presence, or absence, of a correlation between ultrasonic root-end preparation and the formation of cracks. The present study was conducted on human teeth, extracted for periodontal reasons. After root canal treatment, roots were resected 3 mm from the anatomical apex by using a high-speed handpiece and carbide burs. The resected teeth were retroprepared by using an ultrasonic tip (R1D, Piezomed, W&H, Bürmoos, Austria), setting the piezoelectric device at maximum power available for the tip. Time required for the retropreparation was recorded. Before and after retropreparation, all roots were photographed under a stereomicroscope and analyzed by two different operators to evaluate: (a) the presence and extension of dentinal cracks and (b) the morphology of root-end preparation. Finally, piezoelectric tips were analyzed by scanning electron microscopy (SEM) to evaluate morphologic changes after use. A total of 43 single roots (33 with one root canal, 10 with two root canals) were treated. Average preparation time was 1 minute and 54 seconds. None of the roots without initial cracks developed new cracks after retropreparation. Quality of the preparation margins was fairly equal among the prepared specimens. None of the piezoelectric tips broke during instrumentation, and SEM analysis showed minimal surface wear of the tips after performing 11 retropreparations. Within the limits of the present study, the tested piezoelectric system does not seem to represent a major cause for root crack formation. Pre-existing cracks may expand after ultrasound root-end preparation.
尽管超声在牙髓外科手术中的应用有助于根管的有效清创，但不正确的设备设置或效率低下的超声头似乎会在根尖倒预备过程中产生裂纹。本体外研究的主要目的是确定超声根尖预备与裂纹形成之间是否存在关联。本研究使用因牙周原因拔除的人牙进行。根管治疗后，使用高速手机和硬质合金车针从解剖根尖切除3mm牙根。使用超声头（R1D，Piezomed，W&H，奥地利布尔穆斯）对切除的牙齿进行根尖倒预备，将压电设备设置为该超声头可用的最大功率。记录根尖倒预备所需的时间。在根尖倒预备前后，所有牙根均在体视显微镜下拍照，并由两名不同的操作人员进行分析，以评估：（a）牙本质裂纹的存在和扩展情况，以及（b）根尖预备的形态。最后，通过扫描电子显微镜（SEM）分析压电超声头，以评估使用后的形态变化。共处理了43个单根（33个单根管，10个双根管）。平均预备时间为1分54秒。初始无裂纹的牙根在根尖倒预备后均未出现新的裂纹。预备边缘的质量在制备的标本中相当均匀。在操作过程中，压电超声头均未折断，SEM分析显示在进行11次根尖倒预备后，超声头的表面磨损最小。在本研究的范围内，所测试的压电系统似乎不是导致牙根裂纹形成的主要原因。超声根尖预备后，原有的裂纹可能会扩大。
