| Objectives:In vitro comparison of different root canal irrigating fluids used as the final rinse to clean the root canal inner dentin.It aims to provide a theoretical basis for the clinical selection of the best terminal irrigation plan.Methods:1.The 60 single dental pulps obtained were trimmed to a length of 10 mm and the thickness was the same,randomly divided into 6 groups,each weighed and the weight(mg)was recorded.Put 6 groups of pulp into 5.25% NaOCl(group A1),2.5%NaOCl(group B1),1% NaOCl(group C1),2% CHX(group D1),100% OCT(group E1),normal saline(Group F1,control group).The complete dissolution time of pulp in each experimental group was recorded,and the pulp dissolution rate(weight / time)of each experimental group was calculated to evaluate the dissolution performance of the dental pulp tissue in the above solution.2.60 single canal mandibular premolars were selected,and the standardized working length of the roots was 14 mm.The TFA machine was used to prepare root canals with nickel titanium root canal files ML1-3.Each larger size instruments are used to replace 2.5% NaOCl,17% EDTA flush 2ml each alternative irrigation canal,rinsing time was 1min.After the last rinse,rinse the root canal with 5ml of sterile water.All samples were randomly divided into 6 groups,using 5.25% NaOCl(group A2),2.5% NaOCl(group B2),1% NaOCl(group 2C),2% CHX(group D2),100%OCT(E2 Group),normal saline(F2 group)5ml solution was used to rinse the root canal for 1min,and let stand for 4min.Then the root canal was rinsed with 5ml of sterile water for 60 s,and the root canal was dried.Split all the samples along the long axis of the tooth,use half of it.Gradient ethanol is dehydrated,gold sprayed,the sample is observed under a scanning electron microscope.Choose root canal crown1/3(10-12 mm from the apex),middle 1/3(6-7mm from the apex),and sharp1/3(1-2mm from the apex)to observe the cleanliness of root canal inner dentin.3.Scanning electron microscopy showed that the cleanliness of the inner wall ofthe root canal 1/3 of the root canal in the A2,B2,and C2 groups was grade I,and almost no debris remained.In the state of corrosion,there was no corrosion of the dentin inside the root canal of group C2,and the structure of the small canal of the dentin was intact.In the D2,E2,and F2 groups,the upper third of the root canal inner dentin was cleaned at level I,with a small amount of debris left.The dentin canal was clear and no obvious damage was seen.The cleanliness of 1/3 of the root canal inner dentin in the A2,B2,and C2 groups is grade I.Among them,A2 shows the destruction of the peritubular dentin structure and excessive corrosion of the dentin..The cleanliness of root canal inner dentin in groups D2 and E2 was grade ?.The cleanliness of the dentin in the root canal of group F2 was ?.The cleanliness of the root canal inner dentin of 1/3 of the apex of A2,B2,and C2 groups was grade ?,and the peritubular dentin structure of B2 and C2 groups was normal.The cleanliness of the dentin in the root canal of group D2 and E2 was?.The cleanliness of the dentin in the root canal of group F2 was ?.Results:1.The weight of pulp in 6 groups was statistically analyzed.The weight of pulp in groups A1,B1,C1,D1,E1,and F1 were 3.02 ± 0.08 mg,3.09 ± 0.08 mg,3.08 ±0.08 mg,3.06 ± 0.07 mg,3.06 ± 0.07 mg,3.07 ± 0.07 mg,There was no statistical difference in the average weight of each experimental group(P> 0.05).2.The pulp tissue of group A1,B1 and C1 was dissolved,the dissolution time was 3.12±0.12 min?4.31±0.28 min?8.64±0.65 min,and the dissolution rate of pulp tissue was0.969±0.014 ug /min?0.718±0.037 ug /min?0.358±0.018 ug /min.Dental pulp tissues in groups D1,E1,and F1 did not dissolve.Comparison between each group found that the dissolution time A1 was less than B1 and C1,and the dissolution rate A1 was greater than B1 and C1.When comparing two by two,the P value was less than 0.01 after statistical analysis,and there were significant differences between the three groups.3.5.25% NaOCl and 2.5% NaOCl are superior to 1% NaOCl in the clearing effect of the root canal wall,but 5.25% NaOCl and 2.5% NaOCl have dentin corrosion on the root canal wall.1% NaOCl has a good cleaning effect on 1/3 andmiddle 1/3 of the dentin on the inner wall of the root canal,and there is no dentin corrosion,but the cleaning effect on the 1/3 of the apex is not good.2% CHX and100% OCT only have a cleaning effect on the root canal inner dentin at 1/3 of the root,but no cleaning effect at the root and 1/3 of the root.Conclusion:1.Sodium hypochlorite has a dissolving effect on dental pulp tissue,but 2%CHX,100% OCT and saline have no dissolving effect on dental pulp tissue.2.The high concentration of sodium hypochlorite dissolves the pulp tissue faster.That is,among the three groups A1,B1,and C1,the dissolution rate of pulp tissue in group A1 is the fastest,the dissolution rate of pulp tissue in group C1 is the slowest,and group B1 is in between.3.5.25% NaOCl and 2.5% NaOCl are superior to 1% NaOCl in the clearing effect of the root canal wall,but 5.25% NaOCl and 2.5% NaOCl have dentin corrosion on the root canal wall.1% NaOCl has a good cleaning effect on 1/3 and middle 1/3 of the dentin on the inner wall of the root canal,and there is no dentin corrosion,but the cleaning effect on the 1/3 of the apex is not good.2% CHX and100% OCT have no obvious cleaning effect on the root canal dentin. |
PDF Full Text Request