Abstract | OBJECTIVE: The aim of this scanning electron microscopic study was to compare the quality and amounts of smear layer generated by 2 brands of nickel-titanium rotary instruments during canal preparation in the apical thirds of curved root canals. STUDY DESIGN: Forty mandibular mesial root canals with intact apex and mean curvature between 30 and 35 degrees were selected for this study. The root canals were randomly divided into 2 instrumentation groups of 15 each. Automated preparation was performed with ProFile ( Dentsply Maillefer, Ballaigues, Switzerland; n = 15) and K3 (SybronEndo, Orange, Calif; n = 15) instrumentss using a crown-down technique. As a control group, barbed broaches (Mani; Matsutani Seisakusho, Takanezawa-Machi Tochibi-Ken, Japan; n = 10) were used to extirpate the necrotic pulp tissue from the root canals. All root canals were prepared to size #35. Glyde (File Prep, Dentsply Maillefer) was used as lubricant and 1% sodium hypochlorite solution as irrigant. At the conclusion of the experiments, all roots were split longitudinally and the root canal walls were examined at the apical third from 2 different perspectives using a scanning electron microscope. A 4-category scoring system for assessing the smear layer accumulation was used, and the resulting scores were statistically analyzed. RESULTS: Less smear layer was obtained in the K3 group at the selected apical third of curved root canals (P < .05). However, all instruments left a smear layer. The surface texture of the smear layer, in addition to the depth and the frequency of packed materials into the dentinal tubules, varied with instrument type. CONCLUSIONS: This finding may imply that, compared to ProFile, compression of the remaining smear layer is minimized when using the K3 rotary nickel-titanium system.
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Authors | Kee-Yeon Kum, Reza B Kazemi, Bruce Y Cha, Qiang Zhu |
Journal | Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics
(Oral Surg Oral Med Oral Pathol Oral Radiol Endod)
Vol. 101
Issue 4
Pg. 536-41
(Apr 2006)
ISSN: 1528-395X [Electronic] United States |
PMID | 16545720
(Publication Type: Comparative Study, Evaluation Study, Journal Article)
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Chemical References |
- Dental Alloys
- titanium nickelide
- Nickel
- Titanium
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Topics |
- Dental Alloys
- Dental Instruments
- Dental Pulp Cavity
(anatomy & histology, ultrastructure)
- Dentin
(ultrastructure)
- Equipment Design
- Humans
- Microscopy, Electron, Scanning
- Molar
- Nickel
- Root Canal Preparation
(instrumentation)
- Smear Layer
- Statistics, Nonparametric
- Titanium
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