Evaluation of the Effect of Furcation Perforation on the Fracture Resistance of Endodontically Treated Mandibular Molars

Document Type : Original Article


1 Private Practice, Yasuj, Iran

2 Department of Restorative Dentistry, School of Dentistry, Qazvin University of Medical Sciences, Qazvin, Iran

3 Private Practice, Kerman, Iran

4 Department of Endodontics, School of Dentistry, Kerman University of Medical Sciences, Kerman, Iran

5 Endodontology Research Center, Kerman University of Medical Sciences, Kerman, Iran



Background: Root perforations are among the most common procedural complications during root canal treatment; these complications have a poor prognosis. This study aimed to evaluate the effect of furcation perforation on the fracture resistance of endodontically treated mandibular molars.
Method: Sixty intact extracted mandibular molars were divided into two groups; with a marginal ridge (access only) and without a marginal ridge (MOD and access cavity preparation). The two groups underwent endodontic treatment and were divided into three subdivisions: the first group was prepared without any furcal perforation, the second group had a 1-mm perforation in the furcation area, and the third group was prepared with a 3-mm perforation in the furcation area. The furcation perforation site was filled with calcium hydroxide powder and covered with glass-ionomer (GI). The teeth were restored with posterior composite resin. The teeth were then mounted in acrylic blocks and tested with a Testometric machine under compressive strengths. The fracture resistance diagram of each tooth was drawn. The data were analyzed with two-way ANOVA. The fracture patterns were evaluated after separating the teeth from acrylic blocks.
Results: Loss of marginal ridge had no significant effect on fracture resistance measurements (P=0.312), but the furcal perforation variable resulted in significant differences in fracture resistance measurements (P=0.004). Teeth without furcal perforation differed significantly from the teeth with a 3-mm furcal perforation in fracture resistance (P=0.009). The 1-mm furcal perforation group differed significantly from the 3-mm furcal perforation group in fracture resistance (P=0.011).
Conclusion: The teeth with a 3-mm furcal perforation exhibited lower fracture resistance than the two other groups.


  1. Touré B, Faye B, Kane AW, Lo CM, Niang B, Boucher Y. Analysis of reasons for extraction of endodontically treated teeth: a prospective study. J Endod 2011; 37(11):1512-5. doi: 10.1016/j.joen.2011.07.002.
  2. Hussain SK, McDonald A, Moles DR. In vitro study investigating the mass of tooth structure removed following endodontic and restorative procedures. J Prosthet Dent 2007; 98(4):260-9. doi: 10.1016/S0022-3913(07)60110-3.
  3. Oskoee SS, Oskoee PA, Navimipour EJ, Shahi S. In vitro fracture resistance of endodontically-treated maxillary premolars. Oper Dent 2007; 32(5):510-4. doi: 10.2341/06-149.
  4. Sabeti M, Kazem M, Dianat O, Bahrololumi N, Beglou A, Rahimipour K, 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(9):1402-6. doi: 10.1016/j.joen.2018.05.006.
  5. Regan JD, Witherspoon DE, Foyle D. Surgical repair of root and tooth perforations. Endod Topics 2005; 11(1):152-78. doi: 10.1111/j.1601-1546.2005.00183.x.
  6. Kvinnsland I, Oswald RJ, Halse A, Grønningsaeter AG. A clinical and roentgenological study of 55 cases of root perforation. Int Endod J 1989; 22(2):75-84. doi: 10.1111/j.1365-2591.1989.tb00509.x.
  7. Seltzer S, Sinai I, August D. Periodontal effects of root perforations before and during endodontic procedures. J Dent Res 1970; 49(2):332-9. doi: 10.1177/00220345700490022301.
  8. Rosen H. Operative procedures on mutilated endodontically treated teeth. J Prosthet Dent 1961; 11(5):973-86. doi: 10.1016/0022-3913(61)90158-5.
  9. Natali AN, Pavan PG, Scarpa C. Numerical analysis of tooth mobility: formulation of a non-linear constitutive law for the periodontal ligament. Dent Mater 2004; 20(7):623-9. doi: 10.1016/j.dental.2003.08.003.
  10. Silveira FF, Nunes E, Soares JA, Ferreira CL, Rotstein I. Double ‘pink tooth’ associated with extensive internal root resorption after orthodontic treatment: a case report. Dent Traumatol 2009; 25(3):e43-7. doi: 10.1111/j.1600-9657.2008.00755.x.
  11. Soares CJ, Martins LR, Fonseca RB, Correr-Sobrinho L, Fernandes Neto AJ. Influence of cavity preparation design on fracture resistance of posterior Leucite-reinforced ceramic restorations. J Prosthet Dent 2006; 95(6):421-9. doi: 10.1016/j.prosdent.2006.03.022.
  12. Steele A, Johnson BR. In vitro fracture strength of endodontically treated premolars. J Endod 1999; 25(1):6-8. doi: 10.1016/S0099-2399(99)80389-6.
  13. Setzer FC, Boyer KR, Jeppson JR, Karabucak B, Kim S. Long-term prognosis of endodontically treated teeth: a retrospective analysis of preoperative factors in molars. J Endod 2011; 37(1):21-5. doi: 10.1016/j.joen.2010.10.005.
  14. de V Habekost L, Camacho GB, Azevedo EC, Demarco FF. Fracture resistance of thermal cycled and endodontically treated premolars with adhesive restorations. J Prosthet Dent 2007; 98(3):186-92. doi: 10.1016/S0022-3913(07)60054-7.
  15. Jamshidy L, Amirkhani Z, Sharifi R. Effect of furcation perforation size on fracture resistance of mandibular first molar. Dent Hypotheses 2019; 10(1):9-13.
  16. Askerbeyli Örs S, Aksel H, Küçükkaya Eren S, Serper A. Effect of perforation size and furcal lesion on stress distribution in mandibular molars: a finite element analysis. Int Endod J 2019; 52(3):377-84. doi: 10.1111/iej.13013.
  17. Gokturk H, Karaarslan ES, Tekin E, Hologlu B, Sarıkaya I. The effect of the different restorations on fracture resistance of root-filled premolars. BMC Oral Health 2018; 18(1):196. doi: 10.1186/s12903-018-0663-7.
  18. Reeh ES, Messer HH, Douglas WH. Reduction in tooth stiffness as a result of endodontic and restorative procedures. J Endod 1989; 15(11):512-6. doi: 10.1016/S0099-2399(89)80191-8.
  19. Pereira R, Lima DA, Giorgi MC, Marchi GM, Aguiar FH. Evaluation of Bond strength, nanoleakage, and marginal adaptation of bulk-fill composites submitted to thermomechanical aging. J Adhes Dent 2019; 21(3):255-64. doi: 10.3290/j.jad.a42547.
  20. Abe Y, Braem MJ, Lambrechts P, Inoue S, Takeuchi M, Van Meerbeek B. Fatigue behavior of packable composites. Biomaterials 2005; 26(17):3405-9. doi: 10.1016/j.biomaterials.2004.09.029.
  21. Papadogiannis Y, Lakes RS, Palaghias G, Helvatjoglu-Antoniades M, Papadogiannis D. Fatigue of packable dental composites. Dent Mater 2007; 23(2):235-42. doi: 10.1016/j.dental.2006.01.015.
  22. Jensen ME, Redford DA, Williams BT, Gardner F. Posterior etched-porcelain restorations: an in vitro study. Compendium 1987; 8(8):615-7, 20-2.
  23. Eakle W. Effect of thermal cycling on fracture strength and microleakage in teeth restored with a bonded composite resin. Dent Mater 1986; 2(3):114-7. doi: 10.1016/s0109-5641(86)80005-7.