Regenerative Endodontics| Volume 47, ISSUE 6, P932-938, June 2021

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Influence of Progressive Versus Minimal Canal Preparations on the Fracture Resistance of Mandibular Molars: A 3-Dimensional Finite Element Analysis

Published:March 24, 2021DOI:



      This study compared the residual tooth strength and stress distribution of a mandibular molar prepared with different variable tapered file systems using finite element analysis (FEA).


      Two preaccessed mandibular molar TruTeeth (Endo 3DP; Acadental, Lenexa, KS) were subjected to simulated endodontic treatment in this study. One tooth was instrumented with ProTaper Gold (Dentsply Tulsa Dental Specialties, Tulsa, OK), and the other was instrumented with V-Taper 2H (SS White Dental, Lakewood, NJ). The 2 teeth were scanned using micro–computed tomographic imaging, and stereolithographic surface meshes were developed for FEA. Each model was subjected to a 200-N multipoint load-simulating mastication. The results of the FEA provided quantitative and qualitative measurements for von Mises stress distribution and total deformation.


      The maximum von Mises stress was greater in the ProTaper Gold–prepared model than the V-Taper 2H prepared model. In both models, total deformation values were highest in the clinical crown on the buccal aspect of the tooth. The highest stress values were found in the pericervical dentin, and stress decreased apically through the root.


      Within the limitations of this study, it can be concluded that the maximum stress values within the tooth prepared by ProTaper Gold were higher than those in the tooth prepared by V-Taper 2H. Canal preparation with the V-Taper 2H system preserves more pericervical dentin, which may increase the resistance to fracture.

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        • Gluskin A.H.
        • Peters C.I.
        • Peters O.A.
        Minimally invasive endodontics: challenging prevailing paradigms.
        Br Dent J. 2014; 216: 347-353
        • Clark D.
        • Khademi J.
        Modern molar endodontic access and directed dentin conservation.
        Dent Clin North Am. 2010; 54: 249-273
        • Plotino G.
        • Grande N.M.
        • Galanga A.
        • et al.
        Dentine removal in coronal portion of root canals following two prearpation techniques.
        Int Endod J. 2007; 40: 852-858
        • Abdulmunem M.
        • Dabbagh A.
        • Naderi S.
        • et al.
        Evaluation of the effect of dental cements on fracture resistance and fracture mode of teeth restored with various dental posts: a finite element analysis.
        J Eur Ceram Soc. 2016; 36: 2213-2221
        • Alikhasi M.
        • Siadat H.
        • Geramy A.
        • et al.
        Stress distribution around maxillary anterior implants as a factor of labial bone thickness and occlusal load angles: a 3-dimensional finite element analysis.
        J Oral Implantol. 2014; 40: 37-41
        • Adanir N.
        • Belli S.
        Stress analysis of a maxillary central incisor restored with different posts.
        Eur J Dent. 2007; 1: 67-71
        • Yan X.
        • Zhang X.
        • Gao J.
        • et al.
        Maxillary sinus augmentation without grafting material with simultaneous implant installation: a three-dimensional finite element analysis.
        Clin Implant Dent Relat Res. 2015; 17: 515-524
        • Hsu M.L.
        • Chen F.C.
        • Kao H.C.
        • Cheng C.K.
        Influence of off-axis loading of an anterior maxillary implant: a 3-dimensional finite element analysis.
        Int J Oral Maxillofac Implants. 2007; 22: 301-309
        • Kim K.Y.
        • Bayome M.
        • Park J.H.
        • et al.
        Displacement and stress distribution of the maxillofacial complex during maxillary protraction with buccal versus palatal plates: finite element analysis.
        Eur J Orthod. 2015; 37: 275-283
        • Durmuş G.
        • Oyar P.
        Effects of post core materials on stress distribution in the restoration of mandibular second premolars: a finite element analysis.
        J Prosthet Dent. 2014; 112: 547-554
        • Liang R.
        • Guo W.
        • Qiao X.
        • et al.
        Biomechanical analysis and comparison of 12 dental implant systems using 3D finite element study.
        Comput Methods Biomech Biomed Engin. 2015; 18: 1340-1348
        • Tamse A.
        • Fuss Z.
        • Lustig J.
        • et al.
        An evaluation of endodontically treated vertically fractured teeth.
        J Endod. 1999; 25: 506-508
        • Cohen S.
        • Blanco L.
        • Berman L.
        Vertical root fractures: clinical and radiographic diagnosis.
        J Am Dent Assoc. 2003; 134: 434-441
        • Abou-Rass M.
        • Frank A.L.
        • Glick D.H.
        The anticurvature filing method to prepare the curved root canal.
        J Am Dent Assoc. 1980; 101: 792-794
        • Costa A.K.
        • Xavier T.A.
        • Paes-Junior T.J.
        • et al.
        Influence of occlusal contact area on cusp deflection and stress distribution.
        J Contemp Dent Pract. 2014; 15: 699-704
        • Krikeli E.
        • Mikrogeorgis G.
        • Lyroudia K.
        In vitro comparative study of the influence of instrument taper on the fracture resistance of endodontically treated teeth: an integrative approach–based analysis.
        J Endod. 2018; 44: 1407-1411
        • Connert T.
        • Krug R.
        • Eggmann F.
        • et al.
        Guided endodontics versus conventional access cavity preparation: a comparative study on substance loss using 3-dimensional–printed teeth.
        J Endod. 2019; 45: 327-331
        • Gok T.
        • Capar I.D.
        • Akcay I.
        • et al.
        Evaluation of different techniques for filling simulated c-shaped canals of 3-dimensional printed resin teeth.
        J Endod. 2017; 43: 1559-1564
        • Sabeti M.
        • Kazem M.
        • Dianat O.
        • et al.
        Impact of access cavity design and root canal taper on fracture resistance of endodontically treated teeth: an ex vivo investigation.
        J Endod. 2018; 44: 1402-1406
        • Pilo R.
        Residual dentin thickness in mandibular premolars prepared with hand and rotatory instruments.
        J Endod. 1998; 24: 401-404
        • Zandbiglari T.
        • Davids H.
        • Schäfer E.
        Influence of instrument taper on the resistance to fracture of endodontically treated roots.
        Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006; 101: 126-131
        • Patil S.M.
        • Deshpande A.S.
        • Bhalerao R.
        • et al.
        A three-dimensional finite element analysis of the influence of varying implant crest module designs on the stress distribution to the bone.
        Dent Res J. 2019; 16: 145-152
        • Sathorn C.
        • Palamara J.E.
        • Palamara D.
        • et al.
        Effect of root canal size and external root surface morphology on fracture susceptibility and pattern: a finite element analysis.
        J Endod. 2005; 31: 288-292
        • Lam P.P.
        • Palamara J.E.
        • Messer H.H.
        Fracture strength of tooth roots following canal preparation by hand and rotary instrumentation.
        J Endod. 2005; 31: 529-532
        • Rundquist B.D.
        • Versluis A.
        How does canal taper affect root stresses?.
        Int Endod J. 2006; 39: 226-237
        • Özyürek T.
        • Ülker Ö.
        • Demiryürek E.Ö.
        • et al.
        The effects of endodontic access cavity preparation design on the fracture strength of endodontically treated teeth: traditional versus conservative preparation.
        J Endod. 2018; 44: 800-805
        • Krishan R.
        • Paqué F.
        • Ossareh A.
        • et al.
        Impacts of conservative endodontic cavity on root canal instrumentation efficacy and resistance to fracture assessed in incisors, premolars, and molars.
        J Endod. 2014; 40: 1160-1166
        • Plotino G.
        • Grande N.M.
        • Isufi A.
        • et al.
        Fracture strength of endodontically treated teeth with different access cavity designs.
        J Endod. 2017; 43: 995-1000
        • Jiang Q.
        • Huang Y.
        • Tu X.R.
        • et al.
        Biomechanical properties of first maxillary molars with different endodontic cavities: a finite element analysis.
        J Endod. 2018; 44: 1283-1288
        • Silva E.J.
        • Rover G.
        • Belladonna F.G.
        • et al.
        Impact of contracted endodontic cavities on fracture resistance of endodontically treated teeth: a systematic review of in vitro studies.
        Clin Oral Investig. 2018; 22: 109-118
        • Saw L.H.
        • Messer H.H.
        Root strains associated with different obturation techniques.
        J Endod. 1995; 21: 314-320
        • Harvey T.E.
        • White J.T.
        • Leeb I.J.
        Lateral condensation stress in root canals.
        J Endod. 1981; 7: 151-155
        • Dang D.A.
        • Walton R.E.
        Vertical root fracture and root distortion: effect of spreader design.
        J Endod. 1989; 15: 294-301
        • Ricks-Williamson L.J.
        • Fotos P.G.
        • Goel V.K.
        • et al.
        A three-dimensional finite-element stress analysis of an endodontically prepared maxillary central incisor.
        J Endod. 1995; 21: 362-367
        • Zhang Y.
        • Liu Y.
        • She Y.
        • et al.
        The effect of endodontic access cavities on fracture resistance of first maxillary molar using the extended finite element method.
        J Endod. 2019; 45: 316-321