三种连续旋转根管锉对重度弯曲根管预备能力的体外研究OACSTPCD

Objective:To evaluate the root canal preparation ability of three continuous rotary systems using nickel-titanium instruments on resin simulated root canals by experienced and inexperienced operators.Methods:Thirty severely curved resin simulated root canals were randomly divided into groups A and B,and each group was further randomly divided into three subgroups(n= 5).Group A was prepared by an experienced operator using M3-L,ProTaper Next(PTN),and TruNatomy(TN),while an inexperienced operator prepared group B.Root canal preparation time,optical density(OD)of sus-pension fluid of apically extruded debris,and canal transportation were assessed to evaluate the preparation ability of the in-struments.Results:PTN had the longest preparation time(P<0.05),and inexperienced operators using PTN took significant-ly longer(P<0.05).All three nickel-titanium instruments resulted in debris extrusion(P<0.05),with M3-L showing the least debris extrusion(group A:P=0.202,group B:P=0.635).TN demonstrated the best centering ability,with no canal transportation observed at any level.However,at 7～9 mm from the apex,M3-L showed significantly more transportation than TN and PTN(P<0.05).In the PTN group,the inexperienced operator had significantly more transportation in the middle and apical segment(1～5 mm,7 mm)compared to the experienced operator(P<0.05).Conclusion:M3-L showed advantages in preparation time and apically extruded debris,while TN demonstrated the best centering ability.Experienced operators a-chieved better root canal preparation results with PTN.