Date of Completion


Embargo Period



Dr. Qiang Zhu, Dr. Kamran Safavi, Dr. Yu-Hsiung Wang

Field of Study

Dental Science


Master of Dental Science

Open Access

Open Access


Objective: The purpose of this study is to evaluate the depth of troughing needed to locate the mesiobuccal 2 canals in maxillary molars. Troughing the pulp chamber floor can locate hidden or calcified mesio-lingual canals. Materials and Methods: This study utilized 29 extracted maxillary first and second molars with mesiobuccal 2 canals confirmed by sectioning the mesiobuccal root in cross-section 5 mm coronal to the apex. A standard access cavity was prepared and mesiobuccal, distobuccal, and palatal canals were located. A groove was troughed palatal to the mesiobuccal orifice and slightly mesial to the line connecting mesiobuccal and palatal canal orifices until the mesiobuccal 2 canal was visually identified and confirmed with an endodontic file. Troughing depth was determined using digital calipers. Results: The depth of troughing needed to locate the mesio-lingual canal ranged from 0.04 to 2.12 mm. Five teeth needed to be troughed less than 0.5 mm and two teeth needed to be troughed more than 2.0 mm to identify the mesio-lingual canal. Conclusion: In majority of cases, 0.5 mm troughing was sufficient to locate mesio-lingual canals. Clinicians will miss some mesio-lingual canals if troughing is limited to less than 2.0 mm.

Major Advisor

Qiang Zhu