多种方法将氢氧化钙导入弯曲根管内的体外研究OA

Objective:To compare the effects of various methods of introducing calcium hydroxide paste into a stand-ard 20°curved root canal and observe the sealing effect.Methods:Totally 120 resin simulated root canals were prepared to 0625 using M3-pro nickel-titanium instruments.The modules were randomly divided into 8 groups(n=15)according to the different methods of placing the calcium hydroxide paste.Group A-clinical ideal control group,group B-injection group,group C,D,E-Lentulo introduction group(root canal length-0.5 mm,-1 mm,-1.5 mm),group F,G,H-counterclockwise rotation introduction group with 0425 nickel-titanium(root canal length-0.5 mm,-1 mm,-1.5 mm).CBCT analysis was used to evaluate the length of calcium hydroxide paste placement in each group and the situations of proper filling,underfilling and overfilling.Results:The results of the calcium hydroxide paste placement experiment showed that there were significant differ-ences in the average length of calcium hydroxide paste placement to the apical foramen between group A and group B,E,F(P＜0.01).The proper filling rate,except group A,the highest scores were in group D and group H.Group F had the highest score on the overfilling rate.The underfilling rate in group E was the highest.Conclusion:In this experiment,the placement of calcium hydroxide paste using the 0425 nickel-titanium instrument counterclockwise rotation technique(root canal length-1.5 mm)and the Lentulo introduction technique(root canal length-1 mm)in the standard prepared 20° curved root canals was more effective.