In Vitro Evaluation of a Novel Root Canal Endoscope for Visualizing the Apex of Curved Root Canal Models and an Extracted Tooth.

•The dental operating microscope visualized the apex of the straight root canal.•The fabricated root canal endoscope visualized the root apex of both straight and curved root canals.•The resolution of the microscope was higher than the fabricated root canal endoscope.•The root canal endoscope may be useful as a complementary device for accurate diagnosis.