Abstract
Objectives
The purpose of this study was to evaluate the buccolingual curvature at the apical one third in type II mesial canals of mandibular molars using the radius and angle of curvature.
Materials and Methods
Total 100 mandibular molars were selected. Following an endodontic access in the teeth, their distal roots were removed. #15 H- or K-files (Dentsply Maillefer) were inserted into the mesiobuccal and mesiolingual canals of the teeth. Radiographs of the teeth were taken for the proximal view. Among them, type II canals were selected and divided into two subgroups, IIa and IIb. In type IIa, two separate canals merged into one canal before reaching the apex and in type IIb, two separate canals merged into one canal within the apical foramen. The radius and angle of curvature of specimens were examined.
Results
In type II, mean radius of curvature in mesiolingual and mesiobuccal canals were 2.82 mm and 3.58 mm, respectively. The radius of the curvature of mesiolingual canals were significantly smaller than that of mesiobuccal canals in type II, and especially in type IIa. However, there were no statistically significant differences in radius of curvature between mesiobuccal and mesiolingual canals in type IIb and there were no significant differences in angle of curvature between type IIa and IIb.
References
1. Cunningham CJ, Senia ES. A three-dimensional study of canal curvatures in the mesial roots of mandibular molars. J Endod. 1992. 18:294–300.
2. Pineda F, Kuttler Y. Mesiodistal and buccolingual roentgenographic investigation of 7,275 root canals. Oral Surg Oral Med Oral Pathol. 1972. 33:101–110.
3. Cimilli H, Mumcu G, Cimilli T, Kartal N, Wasselink P. The correlation between root canal patterns and interorificial distance in mandibular first molars. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006. 102:e16–e21.
4. Peters OA. Current challenges and concepts in the preparation of root canal systems: a review. J Endod. 2004. 30:559–567.
5. Tzanetakis GN, Kontakiotis EG, Maurikou DV, Marzelou MP. Prevalence and management of instrument fracture in the postgraduate endodontic program at the Dental School of Athens: a five-year retrospective clinical study. J Endod. 2008. 34:675–678.
6. Iqbal MK, Kohli MR, Kim JS. A retrospective clinical study of incidence of root canal instrument separation in an endodontics graduate program: a PennEndo database study. J Endod. 2006. 32:1048–1052.
7. Vertucci FJ. Root canal anatomy of the human permanet teeth. Oral Surg Oral Med Oral Pathol. 1984. 58:589–599.
8. Sattapan B, Nervo GJ, Palamara JE, Messer HH. Defects in rotary nickel-titanium files after clinical use. J Endod. 2000. 26:161–165.
10. Parashos P, Messer HH. Rotary NiTi instrument fracture and its consequence. J Endod. 2006. 32:1031–1043.
11. Wolcott S, Wolcott J, Ishley D, Kennedy W, Johnson S, Minnich S, Meyers J. Separation incidence of protaper rotary instruments: a large cohort clinical evaluation. J Endod. 2006. 32:1139–1141.
12. Kartal N, Cimilli HK. The degrees and configurations of mesial canal curvatures of mandibular first molars. J Endod. 1997. 23:358–362.
13. Schneider SW. A comparison of canal preparations in straight and curved root canals. Oral Surg Oral Med Oral Pathol. 1971. 32:271–275.
14. Weine FS. Endodnotic therapy. 1996. 5th ed. St. Louis: Mosby;356–357.
15. Kyomen SM, Caputo AA, White SN. Critical analysis of the balanced force technique in endodontics. J Endod. 1994. 20:332–337.
16. Hankins PJ, ElDeeb ME. An evaluation of the canal master, balanced force, and step-back techniques. J Endod. 1996. 22:123–130.
17. Günday M, Sazak H, Garip Y. A comparative study of three different root canal curvature measurement techniques and measuring the canal access angle in curved canals. J Endod. 2005. 31:796–798.
18. Pruett JP, Clement DJ, Carnes DL Jr. Cyclic fatigue testing of nickel-titanium endodontic instruments. J Endod. 1997. 23:77–85.
19. Jeong H, Park SJ, Park SH, Choi GW. Morphology of the apical root canal system in Korean mandibular first molar. J Korean Acad Conserv Dent. 2009. 34:137–144.
20. Zelada G, Varela P, Martín B, Bahíllo JG, Magán F, Ahn S. The effect of rotational speed and the curvature of root canals on the breakage of rotary endodontic instruments. J Endod. 2002. 28:540–542.
21. Alomairy KH. Evaluating two techniques on removal of fractured rotary nickel-titanium endodontic instruments from root canals: an in vitro study. J Endod. 2009. 35:559–562.
22. Kum KY, Kim SY, Kim ES, Kim HC, Baek SH, Cho YB, Hwang HK. Practice and application of NiTi rotary systems in clinical endodontics. 2006. 1st ed. Seoul: DaehanNarae Publishing Inc.;18–37.
23. Lee DG, Park JM, Hwang HK. A study on the c-shaped root canal system of mandibular second molar. J Korean Acad Conserv Dent. 2007. 32:335–342.
24. Slowey RR. Root canal anatomy. Road map to successful endodontics. Dent Clin North Am. 1979. 23:555–573.