Root and canal morphology of permanent mandibular molars in a Sudanese population H. A. Ahmed, N. H. Abu-bakr, N. A. Yahia & Y. E. Ibrahim Conservative Dentistry Division, Department of Oral Rehabilitation, Faculty of Dentistry, University of Khartoum, Khartoum, Sudan Abstract Ahmed HA, Abu-bakr NH, Yahia NA, Ibrahim YE. Root and canal morphology of permanent mandibular molars in a Sudanese population. International Endodontic Journal, 40, 766–771, 2007. Aim To investigate variations in the root canal systems of first and second permanent mandibular molar teeth in a Sudanese population using a clearing technique. Methodology Two hundred extracted first and sec- ond permanent mandibular molars from three cities in the state of Khartoum were studied. Access cavities were prepared and pulp tissue was removed by immersion in 5% sodium hypochlorite under ultra- sonication; Indian ink was then injected into the root canal systems assisted by a vacuum applied apically. The teeth were rendered clear by demineralization and immersion in methyl salicylate before evaluation. The following observations were made (i) number of roots and their morphology; (ii) number of root canals per tooth; (iii) number of root canals per root and (iv) root canal configuration. Results Overall 59% of mandibular first molars had four canals with 3% having a third distolingual root. Seventy-eight per cent of second mandibular molars had two separate flat roots, whilst 10% were C-shaped. The most common canal system configurations were type IV (73%) and type II (14%). Inter-canal commu- nications were more common in the mesial roots. The prevalence of inter-canal communications was 65% in first molars and 49% in second molars. Conclusions In this sample of Sudanese teeth, 59% of the mandibular first permanent molars had four root canals whilst 10% of the mandibular second molars had C-shaped roots/canals. Keywords: C-shape canal, canal morphology, clear- ing technique, mandibular molars. Received 25 June 2006; accepted 9 March 2007 Introduction The study of root and canal anatomy has endodontic significance (Vertucci 1984). Moreover, the morphol- ogy of pulp systems varies greatly in different races and in different individuals within the same race. It is important to be familiar with variations in tooth anatomy and characteristic features in various racial groups as this knowledge can aid location, negotiation and management of canals during root canal treatment. A number of studies have shown trends in the shape and number of canals amongst different races (Somogyi-Csimazia & Simmons 1971, Curzon 1974, Reichart & Metah 1981, Walker 1988a, Weine et al. 1988, Weine 1998, Sperber & Moreau 1998). Textbooks of endodontics state that C-shaped canals in mandibular second molars are common (Walton & Torabinenjad 1996). There is a significant ethnic variation in the incidence of C-shaped molars, that ranges between 10% and 32.7% (Kotoku 1985, Yang et al. 1988, Gaby et al. 1999, Al-Fouzan 2002, Gulabivala et al. 2002, Seo & Park 2004). Many investigations have examined the configura- tions of root canal system using techniques, such as radiographs, decalcification, sectioning, replication and computerized-aided techniques (Mayo et al. 1986, Baurmann 1994, Blaskovic-Subat et al. 1995, Omer Correspondence: Dr Neamat Hassan Abu-bakr, Head of Conservative Dentistry Division, Department of Oral Rehabil- itation, Faculty of Dentistry, University of Khartoum, PO Box 102, Khartoum 11111, Sudan (Tel.: +249912297332; fax: +249183780088; e-mail: neamat@yahoo.com). doi:10.1111/j.1365-2591.2007.01283.x International Endodontic Journal, 40, 766–771, 2007 ª 2007 International Endodontic Journal 766