Substitutive Dental Science Department, College of Dentistry, Taibah University, Al Madinah, Saudi Arabia.
Department of Endodontics, College of Dentistry, Taibah University, Al Madinah, Saudi Arabia.
BMC Oral Health. 2024 Sep 27;24(1):1135. doi: 10.1186/s12903-024-04901-7.
The aim of this study was to determine the cutting efficiency of different diamond rotary instrument types for sectioning monolithic zirconia and lithium disilicate anatomical crowns.
The study used 30 diamond rotary instruments divided into three groups: Zirconia cutting diamond bur (White Z), super coarse grit diamond bur (KBlack), and medium coarse grit diamond bur (KBlue); Two subgroups were assigned based on the crown materials including monolithic zirconia (5YSZ) and lithium disilicate (e.max) ceramics. The cutting efficiency was assessed by measuring the time required to fully section the crowns, followed by scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) of the dental burs before use and after every sectioned crown. A three-way ANOVA examined the effects of bur type, material type, and sectioning stage. If interaction exists, one-way ANOVA was used to compare the different subgroups, followed by the Tukey post hoc test. The significance level was assigned at α ≤ 0.05.
The results exhibited various cutting efficiencies among diamond rotary instruments and ceramic crown materials. White Z demonstrated superior cutting efficiency of zirconia crown compared with KBlack and KBlue for the first cutting cycles (p ≤ 0.05); the results tend to be more comparable at the third cutting cycle. However, the super coarse diamond bur exhibited higher efficiency in cutting lithium disilicate crowns than white Z and KBlue burs through all three cutting cycles(p ≤ 0.05). The diamond bur-cutting efficiency diminished after each use, irrespective of the bur type or the crown material (p ≤ 0.05); this was represented by the reduction of carbon and increased nickel matrix ratio after each bur usage.
White Z diamond bur showed higher cutting efficiency of zirconia in the first two cutting cycles; super coarse diamond bur is more efficient for cutting lithium disilicate crown in all of the cutting cycles. The amount of diamond on the burs reduced after each use, with no great impact on the material type when sectioning lithium disilicate and 5YSZ crowns.
This study provides valuable insights for dental practitioners in selecting the appropriate diamond rotary instrument for crown sectioning. Practitioners can minimize the risk of damage and reduce the time required for crown removal, improving patient outcomes.
本研究旨在确定不同类型的金刚石旋转器械在切割整体氧化锆和锂硅酸盐解剖冠时的切割效率。
本研究使用了 30 种金刚石旋转器械，分为三组：氧化锆切割金刚石磨头（White Z）、超粗粒度金刚石磨头（KBlack）和中粗粒度金刚石磨头（KBlue）；根据冠材料分为两组，包括整体氧化锆（5YSZ）和锂硅酸盐（e.max）陶瓷。通过测量完全切割冠所需的时间来评估切割效率，然后在使用前和每次切割冠后对牙科磨头进行扫描电子显微镜（SEM）和能谱分析（EDS）。三因素方差分析考察了磨头类型、材料类型和切割阶段的影响。如果存在交互作用，则采用单向方差分析比较不同亚组，然后采用 Tukey 事后检验。显著性水平设定为α≤0.05。
研究结果显示，金刚石旋转器械和陶瓷冠材料之间的切割效率存在差异。White Z 在第一个切割循环中对氧化锆冠的切割效率优于 KBlack 和 KBlue（p≤0.05）；在第三个切割循环中，结果趋于更加可比。然而，超粗金刚石磨头在所有三个切割循环中对锂硅酸盐冠的切割效率均高于 White Z 和 KBlue 磨头（p≤0.05）。无论磨头类型或冠材料如何，每次使用后金刚石磨头的切割效率都会降低（p≤0.05）；这表现为每次使用后磨头上的金刚石减少，而镍基矩阵的比例增加。
White Z 金刚石磨头在前两个切割循环中对氧化锆的切割效率更高；超粗金刚石磨头在所有切割循环中对切割锂硅酸盐冠更有效。每次使用后，磨头上的金刚石数量都会减少，但在切割锂硅酸盐和 5YSZ 冠时，对材料类型的影响不大。
本研究为牙科医生选择合适的金刚石旋转器械进行冠部切割提供了有价值的信息。医生可以降低冠移除过程中损坏的风险，并减少所需时间，从而改善患者的治疗效果。
