Document Type: Original Article


1 Dept. of Endodontic, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran

2 Dentist


Statement of problem: Missed canal is one of the main reasons of the failure of root canal therapy. Poor knowledge of root canal anatomy may result in this problem. Each tooth has specific anatomical characteristics which could relatively be assessed by radiography.Purpose: This study aimed to survey the variety of second maxillary molar root canal anatomy in Mashhad population.Materials and Methods: In this descriptive study, 103 human adult second maxillary molar extracted in different districts in Mashhad were chosen. After preparation of the access cavity, the teeth were embedded in Naocl 5.25% for resolution of the pulp tissue. For decalcification, the teeth were soaked in HCL 10% for 24 hours and washed in running water for 12 hours. They were dehydrated in alcohol 70-100% and finally cleared by Methylsalicylate and pure alcohol after 3 hours of soaking. Methylen blue 2% was injected to the canals and immediately evaluated with 8x magnification. The root canals were classified by Vertucci category.Results: Different types of canals in mesiobuccal  root were as follows: 45.7%  type I, 16.5% type II, 5.8% type III , 12.6% type IV, 6.9% type V, 4.9% type VI and 3.9% type VII.  In two teeth, the distobuccal and palatal root were fused, having a C-Shaped canal, and 2 teeth had only two roots (buccal and palatal). Therefore, type I was seen 96% and 98% in the distobuccal and palatal roots, respectively.Conclusion: Due to the high prevalence of extra canal in the mesiobuccal root of the second maxillary molar (52.5%), the clinicians have to carefully explore the four canals in radiography and perform clinical evaluation; otherwise, treatment failure is inevitable.Key words: Canal, Configuration, Anatomy, Molar, Maxilla