Mandibular First Molar with a Single Root and Single Canal

Successful endodontic management of mandibular first molar with a single root and single canal is diagnosed with the aid of dental operating microscope and multiple angled radiographs. In addition all the mandibular molars and premolars were single rooted on either side. 1. Introduction A thorough knowledge of root canal anatomy is necessary to achieve appropriate cleaning and shaping of the root canal system and ensure success of endodontic treatment [1]. Very often, the mandibular first molars require endodontic treatment as they are the first permanent posterior teeth to erupt and are commonly affected by caries [2]. Typically, the mandibular first molar presents with 2 well-defined roots: a mesial root with two canals and a distal root with one or two canals. Variations in the form, configuration, and number of root canals in mandibular molars have been discussed extensively in endodontic literature [3, 4]. These include mandibular first molar with five, six, and seven root canals [5–7], middle mesial canal [8], middle distal canal [9], four canals in mesial root [10], four canals in distal root [11], radix entomolaris [12], and “C-” shaped canal [13]. These reports predominantly include cases with more number of canals than normal. However, the clinician should also be aware of the possibility of the existence of lesser number of roots or canals. Gopikrishna et al. published a case of single root with a single canal in a maxillary first molar [14]. Recently, Krithikadatta et al. have reported a case of a mandibular first molar with two roots and two root canals [15]. The purpose of this paper is to report the uncommon anatomy of a mandibular first molar with a single root and single canal, which has not been reported in endodontic literature. 2. Case Report A 28-year-old male patient with the chief complaint of spontaneous pain in the lower right posterior tooth was referred for root canal treatment. History revealed intermittent pain for the past 1 month, which had increased in intensity for the past 4 days. Subjective symptoms included prolonged sensitivity to thermal stimuli and an increase in intensity of pain, which awakened the patient throughout the night. The patient’s medical history was noncontributory. Clinical examination of the right mandibular first molar revealed the presence of a large distoocclusal carious lesion which was tender on percussion and also the presence of a single root. Periodontal probing around the tooth and mobility were within physiological limits. Vitality testing with dry ice (RC Ice; Prime Dental Products Pvt.