Journal of Prosthetic Dentistry
Research and Education| Volume 126, ISSUE 4, P586.e1-586.e9, October 2021

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A 3-dimensional finite element and in vitro analysis of endocrown restorations fabricated with different preparation designs and various restorative materials


      Statement of problem

      The preparation design and fabrication materials directly affect the clinical success of endocrown restorations, and yet, knowledge is lacking about the biomechanical impact of specific designs or materials on endocrown restorations.


      The purpose of this in vitro and finite element analysis study was to evaluate the biomechanical behavior of endocrown restorations.

      Material and methods

      A total of 36 freshly extracted mandibular first molars were collected. The teeth were prepared as per 2 different preparation geometries: with the buccal wall intact (Class 2) and without the buccal wall (Class 3). Teeth were restored with endocrowns made from 3 different fabricating materials, Vita Enamic, GC Cerasmart, and Lava Ultimate. To analyze the in vitro fracture strength, cemented endocrowns were loaded in a universal test machine with a 200-N oblique force until the restoration fractured. Finite element analysis was used to evaluate the stress distribution on both the dentin tissue and the restorative materials. The data were analyzed with a 2-way ANOVA test and the Tukey post hoc test (α=.05).


      No significant differences were found between the different preparation designs (Class 2 and Class 3) on fracture strength (P>.05). The highest mean ±standard deviation fracture strength values were found in the Lava Ultimate material (Class 2, 606.20 ±293; Class 3, 659.40 ±226 N) (P>.05), but the lowest fracture strength test values were obtained in the Vita Enamic material (Class 2, 439.60 ±136; Class 3, 340 ±98 N) (P>.05) for both preparation design test groups.


      A statistically significant difference was not found between the 2 tooth preparation classifications. However, significant differences were observed among the test groups in the Class 2 preparation specimens. The Class 2 preparation design exhibited a higher number of irreparable failures.
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        • Faria A.C.L.
        • Rodrigues R.C.S.
        • Antunes R.P.D.
        • de Mattos M.D.C.
        • Ribeiro R.F.
        Endodontically treated teeth: characteristics and considerations to restore them.
        J Prosthodont Res. 2011; 55: 69-74
        • Schwartz R.S.
        • Robbins J.W.
        Post placement and restoration of endodontically treated teeth: a literature review.
        J Endod. 2004; 30: 289-301
        • Zhu Z.
        • Dong X.-Y.
        • He S.
        • Pan X.
        • Tang L.
        Effect of post placement on the restoration of endodontically treated teeth: a systematic review.
        Int J Prosthodont. 2015; 28: 475-483
        • Gonzalez-Lopez S.
        • De Haro-Gasquet F.
        • Vilchez-Diaz M.A.
        • Ceballos L.
        • Bravo M.
        Effect of restorative procedures and occlusal loading on cuspal deflection.
        Oper Dent. 2006; 31: 33-38
        • Naumann M.
        • Schmitter M.
        • Krastl G.
        Postendodontic restoration: endodontic post-and-core or no post at all.
        J Adhes Dent. 2018; 20: 19-24
        • Sedrez-Porto J.A.
        • da Rosa WLdO.
        • Da Silva A.F.
        • Münchow E.A.
        • Pereira-Cenci T.
        Endocrown restorations: a systematic review and meta-analysis.
        J Dent. 2016; 52: 8-14
        • Bindl A.
        • Mormann W.H.
        Clinical evaluation of adhesively placed Cerec endo-crowns after 2 years-preliminary results.
        J Adhes Dent. 1999; 1: 255-266
        • Govare N.
        • Contrepois M.
        Endocrowns: a systematic review.
        J Prosthet Dent. 2020; 123: 411-418
        • Dietschi D.
        • Duc O.
        • Krejci I.
        • Sadan A.
        Biomechanical considerations for the restoration of endodontically treated teeth: a systematic review of the literature, part II (evaluation of fatigue behavior, interfaces, and in vivo studies).
        Quintessence Int. 2008; 39: 117-129
        • Reeh E.S.
        • Messer H.H.
        • Douglas W.H.
        Reduction in tooth stiffness as a result of endodontic and restorative procedures.
        J Endod. 1989; 15: 512-516
        • Robbins J.W.
        Restoration of the endodontically treated tooth.
        Dent Clin North Am. 2002; 46: 367-384
        • Biacchi G.
        • Basting R.
        Comparison of fracture strength of endocrowns and glass fiber post-retained conventional crowns.
        Oper Dent. 2012; 37: 130-136
        • Pissis P.
        Fabrication of a metal-free ceramic restoration utilizing the monobloc technique.
        Pract Periodontics Aesthet Dent. 1995; 7: 83-94
        • Tikku A.P.
        • Chandra A.
        • Bharti R.
        Are full cast crowns mandatory after endodontic treatment in posterior teeth?.
        J Conserv Dent. 2010; 13: 246-248
        • Belleflamme M.M.
        • Geerts S.O.
        • Louwette M.M.
        • Grenade C.F.
        • Vanheusden A.J.
        • Mainjot A.K.
        No post-no core approach to restore severely damaged posterior teeth: an up to 10-year retrospective study of documented endocrown cases.
        J Dent. 2017; 63: 1-7
        • Einhorn M.
        • DuVall N.
        • Wajdowicz M.
        • Brewster J.
        • Roberts H.
        Preparation ferrule design effect on endocrown failure resistance.
        J Prosthodont. 2019; 28: 237-242
        • Lin C.L.
        • Chang Y.H.
        • Chang C.Y.
        • Pai C.A.
        • Huang S.F.
        Finite element and Weibull analyses to estimate failure risks in the ceramic endocrown and classical crown for endodontically treated maxillary premolar.
        Eur J Oral Sci. 2010; 118: 87-93
        • Aktas G.
        • Yerlikaya H.
        • Akca K.
        Mechanical failure of endocrowns manufactured with different ceramic materials: an in vitro biomechanical study.
        J Prosthodont. 2018; 27: 340-346
        • El-Damanhoury H.M.
        • Haj-Ali R.N.
        • Platt J.A.
        Fracture resistance and microleakage of endocrowns utilizing three CAD-CAM blocks.
        Oper Dent. 2015; 40: 201-210
        • Gaintantzopoulou M.
        • El-Damanhoury H.
        Effect of preparation depth on the marginal and internal adaptation of computer-aided design/computer-assisted manufacture endocrowns.
        Oper Dent. 2016; 41: 607-616
        • Gulec L.
        • Ulusoy N.
        Effect of endocrown restorations with different CAD/CAM materials: 3D finite element and weibull analyses.
        Biomed Res Int. 2017; 2017: 5638683
        • Zarone F.
        • Sorrentino R.
        • Apicella D.
        • Valentino B.
        • Ferrari M.
        • Aversa R.
        • et al.
        Evaluation of the biomechanical behavior of maxillary central incisors restored by means of endocrowns compared to a natural tooth: a 3D static linear finite elements analysis.
        Dent Mater. 2006; 22: 1035-1044
        • Zheng Z.
        • He Y.
        • Ruan W.
        • Ling Z.
        • Zheng C.
        • Gai Y.
        • et al.
        Biomechanical behavior of endocrown restorations with different CAD-CAM materials: a 3D finite element and in vitro analysis.
        J Prosthet Dent. 2020 May 26; S0022-3913(20)30224-9 (Epub ahead of print)
        • Cekic-Nagas I.
        • Ergun G.
        • Egilmez F.
        • Vallittu P.K.
        • Lassila L.V.J.
        Micro-shear bond strength of different resin cements to ceramic/glass-polymer CAD-CAM block materials.
        J Prosthodont Res. 2016; 60: 265-273
        • Taha D.
        • Spintzyk S.
        • Schille C.
        • Sabet A.
        • Wahsh M.
        • Salah T.
        • et al.
        Fracture resistance and failure modes of polymer infiltrated ceramic endocrown restorations with variations in margin design and occlusal thickness.
        J Prosthodont Res. 2018; 62: 293-297
        • Zhi L.
        • Bortolotto T.
        • Krejci I.
        Comparative in vitro wear resistance of CAD/CAM composite resin and ceramic materials.
        J Prosthet Dent. 2016; 115: 199-202
        • Kurtulmus-Yilmaz S.
        • Cengiz E.
        • Ongun S.
        • Karakaya I.
        The effect of surface treatments on the mechanical and optical behaviors of CAD/CAM restorative materials.
        J Prosthodont. 2019; 28: 496-503
        • Spitznagel F.
        • Boldt J.
        • Gierthmuehlen P.
        CAD/CAM ceramic restorative materials for natural teeth.
        J Dent Res. 2018; 97: 1082-1091
        • Krejci I.
        • Daher R.
        Stress distribution difference between Lava Ultimate full crowns and IPS e. max CAD full crowns on a natural tooth and on tooth-shaped implant abutments.
        Odontology. 2017; 105: 254-256
        • Lawson N.C.
        • Bansal R.
        • Burgess J.O.
        Wear, strength, modulus and hardness of CAD/CAM restorative materials.
        Dent Mater. 2016; 32: 275-283
        • D’souza K.M.
        • Aras M.A.
        Three-dimensional finite element analysis of the stress distribution pattern in a mandibular first molar tooth restored with five different restorative materials.
        J Indian Prosthodont Soc. 2017; 17: 53-60