Yazdan Shantiaee1, Omid Dianat2, Golnaz Mosayebi3, Mahshid Namdari4, Patricia Tordik5. 1. Endodontic Department, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Iranian Center For Endodontic Research, Research Institute of Dental Sciences, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 2. Iranian Center For Endodontic Research, Research Institute of Dental Sciences, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Endodontic Division, School of Dentistry, University of Maryland, Baltimore, Maryland. Electronic address: omiddianat@gmail.com. 3. Private Practice, Tehran, Iran. 4. Department of Community Oral Health, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 5. Endodontic Division, School of Dentistry, University of Maryland, Baltimore, Maryland.
Abstract
INTRODUCTION: The aim of this study was to assess the frequency of root crack formation caused by the use of manual instrumentation, 2 rotary systems, and 1 reciprocating system using light-emitting diode transillumination. METHODS:One hundred fifty mandibular premolars were randomly divided into 5 groups (n = 30): control 1, no intervention; control 2, instrumented with hand files; group 3, instrumented with ProTaper Universal rotary files (Dentsply Maillefer, Ballaigues, Switzerland); group 4, instrumented with OneShape rotary files (Micro-Mega, Besancon, France); and group 5: instrumented with the WaveOne reciprocal system (Dentsply Maillefer, Ballaigues, Switzerland). After root canal preparations, the roots were sectioned at 3, 6, and 9 mm from the apex with water irrigation. The slices were inspected under a stereomicroscope with light-emitting diode transillumination from the buccal, lingual, mesial, and distal directions at ×40 magnification to determine the presence/absence of cracks (dentinal defects). The chi-square test was used to analyze the data. RESULTS: There was a significant difference among the groups in crack frequency (P < .05). The 2 single systems had significantly higher cracks than the other 3 groups. At 3 mm from the apex, there were significantly more cracks in groups 4 and 5 than in groups 1, 2, and 3 (P < .05). At 6 mm from the apex, no significant difference was noted (P > .05). At 9 mm from the apex, the frequency of cracks in group 3 was significantly higher (P < .05). CONCLUSIONS: According to the results, using rotary instrumentation can result in some dentinal defects, and single-file systems, regardless of motion type, can cause significantly higher crack formation in the apical third of root canals.
RCT Entities:
INTRODUCTION: The aim of this study was to assess the frequency of root crack formation caused by the use of manual instrumentation, 2 rotary systems, and 1 reciprocating system using light-emitting diode transillumination. METHODS: One hundred fifty mandibular premolars were randomly divided into 5 groups (n = 30): control 1, no intervention; control 2, instrumented with hand files; group 3, instrumented with ProTaper Universal rotary files (Dentsply Maillefer, Ballaigues, Switzerland); group 4, instrumented with OneShape rotary files (Micro-Mega, Besancon, France); and group 5: instrumented with the WaveOne reciprocal system (Dentsply Maillefer, Ballaigues, Switzerland). After root canal preparations, the roots were sectioned at 3, 6, and 9 mm from the apex with water irrigation. The slices were inspected under a stereomicroscope with light-emitting diode transillumination from the buccal, lingual, mesial, and distal directions at ×40 magnification to determine the presence/absence of cracks (dentinal defects). The chi-square test was used to analyze the data. RESULTS: There was a significant difference among the groups in crack frequency (P < .05). The 2 single systems had significantly higher cracks than the other 3 groups. At 3 mm from the apex, there were significantly more cracks in groups 4 and 5 than in groups 1, 2, and 3 (P < .05). At 6 mm from the apex, no significant difference was noted (P > .05). At 9 mm from the apex, the frequency of cracks in group 3 was significantly higher (P < .05). CONCLUSIONS: According to the results, using rotary instrumentation can result in some dentinal defects, and single-file systems, regardless of motion type, can cause significantly higher crack formation in the apical third of root canals.