An Experimental Study On The Ability Of Removing Root Canal Smear Layer By Qmix, EDTA And MTAD

Objective: The effect of removing root canal wall smear layer by Qmix,EDTA and MTAD is compared by scanning electron microscope.Methods: 40 human mandibular premolar teeth with single canal were taken and decoronated to standardize the canal length to 14 mm,they were prepared by S3 rotary system to a root canal preparation of file size 3S,Each time the root canal was mechanically prepared,it was rinsed alternately with 2ml 3% sodium hypochlorite and EDTA gel.Finally,the experimental sample was washed with 5 ml of distilled water for 60 s and the root canal was dried with sterile moisture-absorbing tip.The samples were randomly divided into 4 groups according to the different final irrigations: Group A: 5ml saline for 60s(negative control);Group B: 5ml 17% EDTA solution for 60s;Group C: 5ml MTAD solution for 60s;Group D: 5ml Qmix solution for 60 s.After completion of root canal preparation,the teeth were split into two halves longitudinally,after the experimental sample was processed,the cleanliness of the smear layer of the root canal wall in apical 1/3(Apical 1-2mm),root 1/3(Apical 6-7mm),and upper 1/3 of the root(Apical 10-12mm)was observed under the scanning electron microscope,this study used SPSS17.0 for statistical analysis of the data and the ability of Qmix,EDTA and MTAD to remove the smear layer was evaluated.Results: Qmix group,MTAD group,EDTA group and saline(control group)are compared,the difference is statistically significant(P<0.05),smear removal effect of Qmix group is better than MTAD group,MTAD group is better than EDTA group(P<0.05);Effect of smear layer removal in different sections of each group: There is no significant difference in the saline group(P>0.05);smear removal in the EDTA,MTAD and Qmix groups: apical 1/3 of root<root 1/3<upper 1/3 of the root(P<0.05).Conclusion: Under the experimental conditions,it is suggested that Qmix can remove the smear layer of the root canal more effectively than the three root canal rinsing solutions.EDTA removes the worst smear layer from the root canal,and the smear layer in the upper 1/3 of the same root is the easiest to remove,the apical 1/3 smear layer is the most difficult to remove.