Root canal morphology of mandibular first premolars in an Indian population: a laboratory study

To determine the root canal morphology of mandibular first premolar teeth in an Indian population using a decalcification and clearing technique. One hundred extracted adult mandibular first premolar teeth were studied following decalcification and clearing. The shape of the canal orifice, root canal pattern and length of the teeth were determined. The mandibular first premolars were identified to have a round orifice (38%), oval orifice (44%), flattened orifice (17%) and C-shaped orifice (1%). The canal patterns were classified as Type I (72%), Type II (6%), Type III (3%), Type IV (10%) and Type V (8%) according to Vertucci's classification. C-shaped canals were identified in one tooth (1%). The average length of the teeth was 21.6 mm. Fourteen per cent of the teeth had mesial invaginations of the root. Type I canal patterns were the most frequently occurring in mandibular first premolars amongst the Indian population. 85.7% of the teeth with mesial invagination of the root had either two canals or division of canals.