Deplazes P, Peters O, Barbakow F
Department of Preventive Dentistry, Periodontology, and Cardiology, School of Dentistry, Zurich, Switzerland.
J Endod. 2001 Mar;27(3):196-202. doi: 10.1097/00004770-200103000-00015.
This study measured displacement of canal centers in extracted human teeth after preparation by Lightspeed and nickel-titanium K-files. The specimens were divided into two groups (n = 11), after radiographing the roots from the buccolingual and mesiodistal planes with pathfinding files in situ. More strongly and less strongly curved canals were, respectively, assigned to the Lightspeed and nickel-titanium K-file groups. Using a reassembly technique, cross-sections at 1.25 mm, 3.25 mm, and 5.25 mm from the apices were made of the experimental roots embedded in clear plastic. Stereomicroscopic 35-mm slides were taken of the uninstrumented sectioned canals. The sections were reassembled and then prepared to size 50 Master Apical Rotary and size 40 Master Apical Files, for the Lightspeed and K-file groups, respectively. Similar 35-mm slides of the instrumented canals were taken and electronically superimposed over their uninstrumented counterparts. Displacements of root canal centers after preparation and increases in cross-sectional areas of the prepared root canals were evaluated at specific levels. No significant differences in displacement of canal centers or between the mean cross-sectional areas of the instrumented root canals were recorded between the Lightspeed and K-file groups. Both types of instruments produced similar displacement of canal centers after preparation.
本研究测量了使用LightSpeed器械和镍钛K锉预备后的离体人牙根管中心的位移。在使用导向锉在原位从颊舌向和近远中向对牙根进行影像学检查后，将标本分为两组（n = 11）。弯曲程度较强和较弱的根管分别被分配到LightSpeed组和镍钛K锉组。采用重新组装技术，对包埋在透明塑料中的实验牙根在距根尖1.25 mm、3.25 mm和5.25 mm处制作横截面。对未进行器械预备的根管切片制作体视显微镜35 mm幻灯片。将切片重新组装，然后分别为LightSpeed组和K锉组预备至50号主尖锉和40号主尖锉。对进行器械预备后的根管制作类似的35 mm幻灯片，并将其电子叠加在未进行器械预备的对应根管幻灯片上。在特定水平评估预备后根管中心的位移以及预备后根管横截面面积的增加情况。LightSpeed组和K锉组在根管中心位移或器械预备后根管平均横截面面积之间均未记录到显著差异。两种器械在预备后均产生了类似的根管中心位移。
