Shaping Ability Of Different NiTi Instruments In Simulated Curved Canals

Objective: This study aimed to explore the differences of 3 different NiTi files in preparing curved root canals by measuring the amount of apically extruded debris and apical transportation.Methods: 1.24 standard simulated curved resin canals was randomly subdivided in 3 group.Each group has 8 simulated curved resin canals and they were preparaed by Hyflex CM,M3 pro and XP-endo Shaper,respectively.Composite images were made from the superimposition of pre-and post-instrumentation images.The amount of resin debris removed by each system was measured by using a digital camera and image analysis software.Canal aberrations,apical debris and also the preparation time were also recorded.The data were statistically analyzed by one-way analysis of variance and rank sun test.Results: 1.In terms of root canal centring ability,the center-locating ability of XP-endo Shaper(0.028±0.019mm)is better at the apical 1mm than the other two.And the file also involed with root canal straightening trend(0.083±0.033mm)at the apical 3mm.Hyflex CM has better centring ability in the middle part of the root canal(3mm-6mm),while there is no significant difference between XP-endo Shaper and M3 pro.2.We found that the preparation time of Hyflex CM was about 65.750 s,the preparation time of M3 Pro was about 121.375 s,and the preparation time of XPS was about 103.265 s.There was a statistical difference between each pair of groups(p<0.05).).3.The amount of apical extruded debris of Hyflex CM(0.0028±0.0014g)is less than that of M3 Pro(0.0032±0.0022mm)and XP-endo Shaper(0.0039±0.0015g).There was no significant difference between the three groups(p>0.05).Conclusions:1.From the aspect of the canal centring ability,Hyflex CM had the better centring ability,and the difference between XP-endo Shaper and M3 pro is not obvious.2.Hyflex CM group occupied the most efficient preparation time.XP-endo Shaper is the second.And M3 pro had the longest operative time.3.There were no significant differences in apical extruded debris between each pair of Hyflex CM,M3 pro,and XP-endo Shaper.