Comparative study of shaping efficiency in C-shaped canals of mandibular second molars
10.3321/j.issn:1002-0098.2008.03.007
- VernacularTitle:三种方法预备下颌第二磨牙C形根管成形效果的比较
- Author:
Xin ZHOU
1
;
Qi MA
;
Xing-Zhe YIN
;
Cheng-Fei ZHANG
Author Information
1. 北京大学第三医院
- Keywords:
Dental pulp cavity;
Root canal preparation;
Dental high-speed technique
- From:
Chinese Journal of Stomatology
2008;43(3):151-153
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the shaping efficiency of three instrumentation techniques in the C-shaped canals.Methods Sixty extracted mandibular second molars with C-shaped canals were selected and cross-sectioned at 2,5,8 mm from the apex by using a muffle system as described by Bramante.The teeth containing C-shaped canals were randomly divided into three groups,respectively instrumented using stainless steel K-files in step-back and step-down techniques.and ProTaperTM series in crown-down technique.The digital images of canal cross-sections pre-and post-instrumentation were photographed to evaluate the proportion and position of uninstrumented area.Working length loss and perforation were recorded.Data were analyzed using ANOVA.Results Step-down technique gained smaller uninstrumented area in the coronal third of the canals,while step-beck technique gained the same results in the apical third(P＜0.05).Uninstrumented proportion in apical part was significantly higher than in the middle and the coronal(P＜0.05).Instrumenting type Ⅰ canal as 2 or 3 separated canals Was likely to reduce the miss.There were three perforations in manual stainless steel K-file groups.Conclusions Early opening the coronal part of C-shaped canal,shaping C-shaped canal as two or three separated canals and instrumenting the apical part with step-back technique,seemed to be the effective methods to avoid miss.
