If the pulp of the single rooted canal is triangular in cross-section with the base of the triangle located facially and apex located lingually with the mesial arm longer than the distal, the tooth is most likely:

SHAPE OF ACCESS CAVITY: Maxillary Incisors - Rounded triangle with the apex towards cingulum. Maxillary Canine - Ovoid labiolingually. Maxillary Premolar - Ovoid in Buccolingual direction (Slot shaped). Maxillary Molars - Triangle in the mesial half base towards buccal and apex towards palatal side. Note if asked in exams:            - Rhomboidal (1st choice)             - Rounded Triangle (2nd choice) Modified Access Cavity in maxillary molars (to accommodate accessory orifice):            - Clove leaf.            - Shamrock preparation. MANDIBULAR TEETH: Mandibular Incisors - Narrow rounded triangle or ovoid. Mandibular Canine - Ovoid / funnel shaped. Mandibular Premolar - Ovoid buccolingually. Mandibular Molars - Trapezoidal (1st choice)                     - Rounded Triangle (2nd choice)