A challenging complication during an endodontic treatment or after completion of an endodontic treatment is a vertical root fracture (VRF) of the tooth treated. (1,2) It is a longitudinally oriented fracture of the root extending to the periodontium that may begin in the crown, root apex, or any point in between. The prognosis of endodontically treated tooth with the presence of a VRF is very poor with the treatment of choice being extraction. (3) Removal of caries, access-cavity preparations, canal instrumentation techniques, the effects of irrigation solutions, prolonged exposure to calcium hydroxide, pressure during obturation and tooth/crown preparation for the final restoration, may be ...view middle of the document...
The Self-Adjusting File (SAF; ReDent-Nova, Ra’anana, Israel) is a specially designed flexible and hollow file, which adapts itself to the shape of these canal anatomies and enlarges it, maintaining the original canal shape of the canal. This file works in a transline in-out motion and its abrasive surface removes circumferentially equal amount of radicular dentin thus preventing the chance of over preparation and thus not resulting in weakening of the root canal wall. (12) Various studies have been reported on the formaion of micro-cracks in the radicular dentin after instrumentation. When SAF was compared to the either rotary or reciprocating files it proved to be more superior and also presented in significantly less crack formation. (13,14)
Another single file system is the waveOne (WO; Dentsply Maillefer, Baillagues, Switzerland), which works in a reciprocating manner. The WO reciprocating file depicts a reversed balanced force technique. (10) The CCW engaging angle is 5 times the CW disengaging angle. Strategically, after 3 CCW and CW cutting cycles, the file will have rotated 360°, or one circle. This novel reciprocating movement allows a file to readily progress, efficiently cut, and effectively remove debris out of the canal with fewer chances for endodontic failure/complication. (10)
Most widely used technique for obturating an endodontically treated tooth is lateral compaction technique and is also reported in literature that it has an associated risk of VRF with this technique. (15) Various studies have been carried out and have been reported in literature that the load generated by lateral condensation is less than the load required to fracture the roots excluding the teeth with very weak roots. Hence it is unclear whether the various root canal-filling techniques, result in the VRFs of endodontically treated teeth or not. (16-18)
The fracture resistance of a teeth instrumented by SAF has rarely been reported (19) and no reports when instrumented by PTN rotary file or WO reciprocating file system. Hence, the purpose of this study was to assess and compare the fracture resistance of the teeth after the instrumentation by SAF, PTN and WO files; that were obturated using cold lateral compaction technique.
1. Testori T, Badino M, Castagnola M. Vertical root fractures in endodontically treated teeth: a clinical survey of 36 cases. J Endod 1993;19:87–91.
2. Fuss Z, Lustig J, Tamse A. Prevalence of vertical root fractures in extracted endodontically treated teeth. Int Endod J 1999;32:283–6.
3. Vire DE. Failure of endodontically treated teeth: classification and...