Palma Paulo J, Marques Joana A, Casau Margarida, Santos André, Caramelo Francisco, Falacho Rui I, Santos João Miguel
Institute of Endodontics, Faculty of Medicine, University of Coimbra, 3000-075 Coimbra, Portugal.
Center for Innovation and Research in Oral Sciences (CIROS), Faculty of Medicine, University of Coimbra, 3000-075 Coimbra, Portugal.
Biomedicines. 2020 Sep 28;8(10):383. doi: 10.3390/biomedicines8100383.
The aim of this study is to compare root-end preparation performed with two different ultrasonic tips-CVDentus and NSK-and respective time requirements. After root-end resection, 32 teeth were randomly divided in two groups, according to the ultrasonic tip used for root-end preparation. Preparation time was recorded. Photomicrographs were taken to assess the following parameters: root surface microcracking, marginal integrity and presence of debris. One ultrasonic tip from each group was analyzed through scanning electron microscopy before and after root-end preparation. The significance level was set at α = 0.05. Incidence of microcracks in both groups was 12.5%. Solely intracanal microcracking was found, consistently positioned within the widest side of the remaining dentine. No statistically significant differences were verified between both experimental groups regarding marginal integrity ( = 0.102) and preparation time ( = 0.780), whereas statistical differences ( = 0.003) were found concerning the presence of debris (the minimum registered score was mostly verified in CVDentus group). NSK tips showed major morphological changes, with extensive surface wear and noticeable loss of particles, which was not verified on CVDentus tips. Our findings suggest significant differences regarding root-end preparation walls quality, with CVDentus tips showing better results. Concerning microcracking, as well as preparation time and marginal integrity, both ultrasonic tips showed similar results. Qualitative analysis exposed NSK tips major morphological changes and wear after use, which was not verified on CVDentus tips.
本研究的目的是比较使用两种不同超声尖（CVDentus和NSK）进行根尖预备及其各自所需的时间。根尖切除术后，根据用于根尖预备的超声尖，将32颗牙齿随机分为两组。记录预备时间。拍摄显微照片以评估以下参数：牙根表面微裂纹、边缘完整性和碎屑的存在情况。每组各取一个超声尖在根尖预备前后通过扫描电子显微镜进行分析。显著性水平设定为α = 0.05。两组微裂纹的发生率均为12.5%。仅发现根管内微裂纹，始终位于剩余牙本质最宽的一侧。在边缘完整性（P = 0.102）和预备时间（P = 0.780）方面，两组之间未发现统计学上的显著差异，而在碎屑的存在情况方面发现有统计学差异（P = 0.003）（最低记录分数大多在CVDentus组中得到证实）。NSK尖显示出较大的形态变化，表面磨损广泛且颗粒明显丢失，而CVDentus尖未出现这种情况。我们的研究结果表明，在根尖预备壁质量方面存在显著差异，CVDentus尖显示出更好的结果。在微裂纹、预备时间和边缘完整性方面，两种超声尖显示出相似的结果。定性分析显示，NSK尖在使用后出现较大的形态变化和磨损，而CVDentus尖未出现这种情况。
