The Influence of Crown Ferrule on Fracture Resistance of Endodontically Treated Maxillary Central Incisors

[btn url=”” text_color=”#ffffff” bg_color=”#81d742″ icon=”fa-file-pdf-o” icon_position=”start” size=”14″ id=”” target=”NewWindow”]Download Article[/btn]

13 / Julie Popovski1 / Alesh Dakskobler2 / Ljubo Marion3 / Peter Jevnikar3

1Department of Prosthodontics, Faculty of Dental Medicine, University of Ss. Cyril and Methodius, Skopje, Macedonia (the former Yugoslav Republic of)
2Ceramics Engineering Department, Institute Joseph Stefan (IJS) Ljubljana, Slovenia
3Department of Prosthodontics, Faculty of Medicine (MF), University of Ljubljana, Slovenia


Background: Prefabricated zirconia posts can contribute to increasing the fracture resistance of the endodontically treated teeth. Purpose. This in vitro study compared the fracture resistance of endodontically treated central maxillary incisors prepared with 2 mm ferrule length to the ones without ferrule.

Material and methods: Twenty-four caries-free maxillary central incisors were divided into 2 groups of 12. In group A circumferential external dentin shoulders were prepared for 2 mm external dentin ferrule length. There was no ferrule preparation in Group B. Zirconia VALLPOST BO-S (Ø 1,6 mm), Ljubljana, Slovenia were used with retention forms in the coronary part. Core build-up was made of pressed ceramics (IPS e.max Press, Ivoclar, Liechtenstein). Crowns were manufactured from the same ceramic material (IPS e.max Press, Ivoclar). After root canal treatment and post space preparation, all posts were cemented with an adhesive resin cement (Multilink Automix, Ivoclar). The specimens were embedded in acrylic resin blocks (ProBase Polymer/Monomer, Ivoclar) and loaded at an angle of 45° to the long axis in an Instron Testing Machine 4301 (Instron Corp., USA) at a crosshead speed of 1 mm/min until fracture. Fracture patterns and loads were recorded. A significance level of p<0.05 was used for all comparisons. Two-way analysis of variance was used for statistical analysis. Failure patterns were analyzed with the optical microscope Stereo Discovery V.8 (Carl Zeiss, Germany) and compared using the chi-square nonparametric test.

Results: The mean values (±SD) of fracture loads (N) for the Groups A and B were 664.63N (±49.14) and 519.36N (±71.65) recpectively. Significantly lower failure loads were recorded for the specimens in the group B. Failure patterns within the groups revealed non-catastrophic failure in 70% of the specimens for group A and 85% for group B.

Conclusions: Within the limitations of this in vitro study, it can be concluded that zirconia VALLPOST BO-S (Ø 1,6 mm) with press-ceramic cores and crowns, can be used for restoration of endodontically treated teeth. The teeth prepared with 2 mm external dentin ferrule length were found to be more fracture resistant than teeth without ferrule.

Keywords: Endodontically Treated Teeth; Zirconia Post; Press Core; Press Crown; Ferrule


  1. Schwartz SR, Robbins WJ. Post placement and restoration of endodontically treated teeth: a literature review. J Endod, 2004; 30:289-301.[Crossref]
  2. Tang W, Wu Y, Smales JR. Identifying and reducing risks for potencial fractures in endodontically treated teeth. review article. J Endod, 2010; 36:609-617.[Crossref]
  3. Fraga RC, Chaves BT, Melo GS, Siquera JFJ. Fracture resistance of endodontically treated roots after restoration. J Oral Rehabil, 1998; 25:809-813.[Crossref]
  4. Meyeberg KH, Luthy H, Scharer P. Zirconium post. A new all-ceramic concept for nonvital abutment teeth. J Esthet Dent, 1995; 7:73-80.[Crossref]
  5. Friedel W, Kern M. Fracture strength of teeth restored with all-ceramic posts and cores. Quintessence Int, 2006; 37:289-295.
  6. Zhi-Yue L, Yu-Xing Z. Effects of post core design and ferrule on fracture resistance of endodontically treated maxillary central incisors. J Prosthet Dent, 2003; 83:368-373.
  7. Heydecke G, Butz F, Strub JR. Fracture strength and survival rate of endodontically treated maxillary incisors with approximal cavities after restoration with different post and core systems: an in-vitro study. J Dent, 2001; 29:427-433.[Crossref]
  8. Akkayan B, Guelmez T. Resistance to fracture of endodontically treated teeth restored with different post systems. J Prosthet Dent 2002; 87:431-437.[Crossref]
  9. Dilmener FT, Sipahi C, Dalkiz M. Resistance of three new esthetic post-and-core systems to compressive loading. J Prosthet Dent, 2006; 95:130-136.[Crossref]
  10. Libman WJ, Nicholls JI. Load fatigue of teeth restored with cast posts and cores and complete crowns. Int J Prosthodont, 1995; 8:155-161.
  11. Rosen H. Operative procedures on mutilated endodontically treated teesth. J Prosthet Dent, 1961; 11:973-986.[Crossref]
  12. Whitworth JM, Walls AWG, Wassell RW. Crowns and extra-coronal restorations: Endodontic considerations: the pulp, the root-treated tooth and the crown. Br Dent J, 2002; 192:315-327.
  13. Pereira JR, Valle AL, Shiratori FK, Ghizoni JS, Melo MP. Influence of intraradicular post and crown ferrule on the fracture strength of endodontically treated teeth. Braz Dent J, 2009; 20:297-302.[Crossref]
  14. Akkayan B. An in vitro study evaluating the effect of ferrule length on fracture resistance of endodontically treated teeth restored with fiber-reinforced and zirconia dowel systems. J Prosthet Dent, 2004; 92:155-162.[Crossref]
  15. Jovanovski TS. Assesment of the effects of treatement of the ceramic posts and their effect on fracture resistance on the endodontic treated teeth. (Doctoral dissertation), Faculty of Dental Medicine – Skopje, 2012.
  16. Dakskobler A, Jevnikar P, Oblak C, Kosmac T. The processing-related fracture resistance and reliability of root dental posts made from Y-TZP. J Eur Ceram Soc, 2007; 27:1565-1570.[Crossref] [Web of Science]
  17. Pereira JR, de Ornelas F, Conti PC, do Valle AL. Effect of a crown ferrule on the resistance of endodontically-treated teeth restored with prefabricated posts. J Prosthet Dent, 2006; 95:50-54.[Crossref]
  18. Butz F, Lennon A, Haydecke G, Strub J. Survival rate and fracture strength of endodontically treated maxillary incisors with moderate defect restored with different post and core systems: an in vitro study. Int J Prosthodont, 2001; 14:58-64.
  19. Strub JR, Pontius O, Koutayas S. Survival rate and fracture strength of incisors restored with different post and core systems after axposure in the artificial mouth. J Oral Rehabil, 2001; 28:120-124.[Crossref]
  20. Nothdurft PF, Pospiech RP. Clinical evaluation of pulpless teeth restored with conventionally cemented zirconia posts: A pilot study. J Prosthet Dent, 2006; 95:311-314.[Crossref]
  21. Paul SJ, Werder. Clinical success of zirconium oxide posts with resin composite or glass-ceramic cores in endodontically treated teeth: a 4-year retrospective study. Int J Prosthodont, 2004; 17:524-528.
  22. Oblak C, Jevnikar P, Kosmac T, Funduk N, Marion Lj. Fracture resistance and reliability of new zirconia posts. J Prosthet Dent, 2004; 91:342-348.[Crossref]
  23. Kosmac T, Dakskobler A, Oblak C, Jevnikar P. The strength and hydrothermal stability of Y-TZP ceramics for dental applications. Int J Appl Ceram Technol, 2007; 4:164-174.[Web of Science] [Crossref]
  24. Gegauf AG. Effect of crown lengthening and ferrule placement on static load failure of cemented cast post-cores and crowns. J Prosthet Dent, 2000; 84:169-179.[Crossref]
  25. Butz F, Lennon A, Haydecke G, Strub J. Survival rate and fracture strength of endodontically treated maxillary incisors with moderate defect restored with different post and core systems: an in vitro study. Int J Prosthodont, 2001; 14:58-64.
  26. Assif D, Bitenski A, Pilo R, Oren E. Effect of post design on resistance to fracture of endodontically treated teeth with complete crowns. J Prosthet Dent, 1993; 69:36-40.[Crossref]
  27. Sorensen JA, Engelman MJ. Ferrule design and fracture resistance of endodontically treated teeth. J Prosthet Dent, 1990; 63:429-436.[Crossref]
  28. Meng QF, Chen YM, Guang HB, Yip KHK, Smales RJ. Effect of a ferrule and increased clinical crown length on the in vitro fracture resistance of premolars restored using two dowel-and-core systems. Oper Dent, 2007: 32:595-601.[Crossref] [Web of Science]
  29. Stankiewicz NR, Wilson PR. The ferrule effect: a literature review. IntEndod J, 2002; 35:575-581.
  30. Stankiewicz N, Wilson P. The ferrule effect. Dent Update, 2008; 35:222-224.
  31. Juloski J, Radovic I, Goracci C, Vulevic RZ, Ferrari M. Ferrule effect: A Literature Review. J Endod, 2012; 38:11-19.[Crossref] [Web of Science]
  32. Cohen IB, Pagnillo KM, Newman I, Musikant LB, Deutsch SA. Retention of a core material supported by three post head designs. J Prosthet Dent, 2000;,83:624-628.[Crossref]
  33. Ottl P, Hahn L, Lauer HCH, Fay M. Fracture characteristics of carbon fibre, ceramic and non-palladium endodontic post systems at monotonously increasing loads. J Oral Rehabil, 2002; 29:175-183.[Crossref]
  34. Asmussen E, Peutzfeldt A, Heitmann T. Stiffness, elastic limit, and strength of newewr types of endodontic posts. J Dent, 1999; 27:275-278.[Crossref]
  35. Ozkurt Z, Iseri U, Kazazoglu E. Zirconia ceramic post systems: a literature review and a case report. Dent Mater J, 2010; 29:233-245.[Crossref] [Web of Science]
  36. Ozkurt Z, Kazazoglu E. Clinical success of zirconia in dental applications. J Prosthodont, 2010; 19:64-68.[Crossref]
  37. Hezaimeh N, Gutteridge DL. An in vitro study into the effect of ferrule preparation on the fracture resistance of crowned teeth incorporating prefabricated post and composite core restorations. Int Endod J, 2001; 34:40-46.[Crossref]
  38. Ng CC, Al-Bayat MI, Dumberigue HB, Griggs Ja, Wakefield CW. Effect of no ferrule on failure of teeth restored with bonded posts and cores. Gen Dent, 2004; 52:143-146.
  39. Tjan AHL, Whang SB. Resistance to root fracture of post channels with various thicknesses of buccal dentin walls. J Prosthet Dent, 1985; 53:496-500.[Crossref]
  40. Bateman G, Ricketts D, Saunders W. Fiber-based post systems: a review. Br Dent J, 2003: 195:43-48.
  41. Guzy GE, Nicholls II. In vitro comparison of intact endodontically treated teeth with and without endo-post reinforcement. J Prosthet Dent, 1979: 42:39-44.[Crossref]
  42. Cheung W. A review of the management of endodontically treated teeth: Post, core and the final restoration J Am Dent Assoc, 2005; 136:611-619.[Crossref]
  43. Clarisse CHN, Dumbrigue HB, Al-Bajat IM, Griggs AJ, Wakefield WC. Influence of remaining coronal tooth structure location on the fracture resistance of restored endodontically treated anterior teeth. J Prosthet Dent, 2006; 95:290-296.[Crossref]
  44. Isidor F, Brondum K, Ravnholt G. The influence of post length and crown ferrule length on the resistance to cyclic loading of bovine teeth with prefabricated titanium post. Int J Prosthodont, 1999; 12:79-82.
  45. Milot P, Stein RS. Rooth fracture in endodontically treated teeth related to post selection and crown design. J Prosthet Dent, 1992; 68:428-435.[Crossref]
Citation Information: Balkan Journal of Dental Medicine. Volume 21, Issue 1, Pages 44–49, ISSN (Online) 2335-0245, DOI:, March 2017