| ObjectiveThrough coronal preflaring on 151 root canals need to do a root canal therapy,measured root canal working length twice before and after preflaring.to compare the change of root canal length, in order to find the change rule, guide the clinical work.MethodsCollected from March 2015 to December 2015 to shanxi medical university first hospital dental clinic, to do root canal treatment in 54 patients with 71 teeth, root canal number of a total of 151.Routine preoperative X-ray films in order to understand the morphology of root canal and periapical tissue, use Raypex5 electronic apex locator and 15# stainless steel K file measuring root canal working length L1 before root canal preflaring,and then use nickel titanium Protaper Sx file to prepare the two-thirds of root canal upper,for preflaring of crown root canal measuring root canal length L2 again, and treat L2 as root canal working length, using Protaper nickel titanium equipment combination with stainless steel K file to prepare the root canal with crown down technology to F2, after the completion of root canal preparation,take X-ray film for root cannal with percha obturation, through the formula to calculate the actual length of the root canal WL.Clinical operation all have been done with a doctors who has more than 10 years working experience, measurement and calculation by an assistant to assist complete, every time all measurement take three times, and calculate the average.Will all patients with clinical data,including age, sex, the position of the teeth, diagnosis, and the data by measuring and calculating are recorded in the table, and the data for statistical analysis.Results1. The percentage was 88.7%(134/151) using the apex 15 # K file to measure the length of root canal before preflaring.After using nickel titanium Protaper Sx shaping file prepared the 2/3 of root canal upper, the percentage was 97.3%(147/151).And statistically difference(P < 0.05).2. Comparison of the accuracy,before preflaring, the accuracy was 94.0%, and after preflaring, the accuracy was 94.6%, the total accuracy was 94.3%.Before and after preflaring accuracy comparison, P > 0.05, there was no significant difference.3. The influence of measurement accuracy with age, group 147 root canals which got L2 according age.The young-aged group accuracy was 97.3%, the middle-aged group,accuracy was 97.2%, the elderly group, accuracy was 86.8%, the total accuracy was94.6%.By comparison, P > 0.05, there was no significant difference.4. The influence of different diseases on measurement accuracy, group 147 root canals by diagnosis, the pulpitis group, accuracy was 94.7%, the apical periodontitis group,accuracy was 94.4%. By the statistical comparison, P > 0.05, there was no significant difference.5. Compared the change of the length measured before and after preflaring, with 134 root canal by anterior teeth, premolar and molar group, anterior teeth root canal 10 while after preflaring measure length lower 0.06 mm than before, and premolar root canal 37,after preflaring measure length lower than before by an average of 0.27 mm, molar group87 root canal, root canal length after preflaring reduce 0.47 mm on average.By the statistical comparison, anterior teeth group P > 0.05, there was no significant difference;premolar and molar group P < 0.001, with significant difference.ConclusionsTake root canal length measuring after coronal preflaring, root canal files is easier to reach apical constriction. After preflaring measurement of root canal length is shorter than before, to make up the shortfall for the possibility of loss of root canal length after rootcanal preparation of a curved root canal, provides accurate working length fpr root canal preparation process,and prevents apical constriction be damaged.Advocate the clinician to make coronal preflaring before root canal preparation, improve the quality of root canal preparation, lays the foundation for root canal filling, thus improve the success rate of root canal therapy to a great extent. |
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