Efficacy of Endoscope and Periapical Radiography to Detect Residual Root Canal Filling Using Micro-CT as Reference

Published:December 23, 2022DOI:



      To evaluate the efficacy of examinations by endoscope of root canals to determine residual root canal filling materials by comparison with microcomputed tomographic (micro-CT) images as reference.


      Thirty maxillary second premolars with oval canals received root canal treatment. Then D-Race retreatment files were used to remove the root canal fillings supplemented by XP-endo Finisher. Samples were scanned to reconstruct micro-CT reference images. Images were obtained of all samples from the mesiodistal and buccolingual directions by digital radiography. Then the root canals of specimens mounted in manikins were assessed by endoscope. The radiographic and endoscopic results were scored following comparison with the micro-CT images, which served as a reference, by 2 blinded observers. The interexaminer reliability of the assessments was evaluated by kappa test and the accuracy of endoscopic visualization according to the presence of residual root canal filling materials was compared using Kruskal–Wallis H test and Spearman’s rank order correlation with the level of significance set at 5%.


      The efficiency of the periapical radiography and endoscopy to determine residual root canal filling material was similar in every third of the root canal (P > .05).


      The endoscope detected residual root canal filling material as efficiently as periapical radiography.

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        • Siqueira J.F.
        • Roças I.N.
        • Ricucci D.
        • et al.
        Causes and management of post-treatment apical periodontitis.
        Br Dent J. 2014; 216: 305-312
        • Siqueira Jr., J.F.
        Aetiology of root canal treatment failure: why well-treated teeth can fail.
        Int Endod J. 2001; 34: 1-10
        • Crozeta B.M.
        • Silva-Sousa Y.T.
        • Leoni G.B.
        • et al.
        Microcomputed tomography study of filling material removal from oval-shaped canals by using rotary, reciprocating, and adaptive motion systems.
        J Endod. 2016; 42: 793-797
        • Keleş A.
        • Alcin H.
        • Kamalak A.
        • et al.
        Micro-CT evaluation of root filling quality in oval-shaped canals.
        Int Endod J. 2014; 47: 1177-1184
        • Machado A.G.
        • Guilherme B.P.S.
        • Provenzano J.C.
        • et al.
        Effects of preparation with the self-adjusting file, TRUShape and XP-endo shaper systems, and a supplementary step with XP-endo finisher R on filling material removal during retreatment of mandibular molar canals.
        Int Endod J. 2019; 52: 709-715
        • Schirrmeister J.F.
        • Hermanns P.
        • Meyer K.M.
        • et al.
        Detectability of residual epiphany and gutta-percha after root canal retreatment using a dental operating microscope and radiographs--an ex vivo study.
        Int Endod J. 2006; 39: 558-565
        • Donnermeyer D.
        • Bunne C.
        • Schafer E.
        • et al.
        Retreatability of three calcium silicate-containing sealers and one epoxy resin-based root canal sealer with four different root canal instruments.
        Clin Oral Investig. 2018; 22: 811-817
        • Taşdemir T.
        • Er K.
        • Yildirim T.
        • et al.
        Efficacy of three rotary NiTi instruments in removing gutta-percha from root canals.
        Int Endod J. 2008; 41: 191-196
        • Ordinola-Zapata R.
        • Bramante C.M.
        • Versiani M.A.
        • et al.
        Comparative accuracy of the clearing technique, CBCT and micro-CT methods in studying the mesial root canal configuration of mandibular first molars.
        Int Endod J. 2017; 50: 90-96
        • Patel S.
        • Brown J.
        • Pimentel T.
        • et al.
        Cone beam computed tomography in endodontics—a review of the literature.
        Int Endod J. 2019; 52: 1138-1152
        • Schulze R.
        • Heil U.
        • Gross D.
        • et al.
        Artefacts in CBCT: a Review.
        Dentomaxillofac Radiol. 2011; 40: 265-273
        • de Carvalho Maciel A.C.
        • Zaccaro Scelza M.F.
        Efficacy of automated versus hand instrumentation during root canal retreatment: an ex vivo study.
        Int Endod J. 2006; 39: 779-784
        • Betti L.V.
        • Bramante C.M.
        Quantec SC rotary instruments versus hand files for gutta-percha removal in root canal retreatment.
        Int Endod J. 2001; 34: 514-519
        • Del Fabbro M.D.
        • Taschieri S.
        • Lodi G.
        • et al.
        Magnification devices for endodontic therapy.
        Cochrane Database Syst Rev. 2015; 2015: CD005969
        • Von Arx T.
        • Montagne D.
        • Zwinggi C.
        • et al.
        Diagnostic accuracy of endoscopy in periradicular surgery-a comparison with scanning electron microscopy.
        Int Endod J. 2003; 36: 691-699
        • Slaton C.C.
        • Loushine R.J.
        • Weller R.N.
        • et al.
        Identification of resected root-end dentinal cracks: a comparative study of visual magnification.
        J Endod. 2003; 29: 519-522
        • Yoshii S.
        • Fujimoto M.
        • Okuda M.
        • et al.
        In Vitro Evaluation of a novel root canal endoscope for visualizing the apex of curved root canal models and an extracted tooth.
        J Endod. 2018; 44: 1856-1861
        • Keleş A.
        • Keskin C.
        • Alqawasmi R.
        • et al.
        Accuracy of an endoscope to detect root canal anastomoses in mandibular molar teeth: a comparative study with micro-computed tomography.
        Acta Odontol Scand. 2020; 78: 433-437
        • Moshonov J.
        • Michaeli E.
        • Nahlieli O.
        Endoscopic root canal treatment.
        Quintessence Int. 2009; 40: 739-744
        • Bahcall J.K.
        • Barss J.T.
        Fiberoptic endoscope usage for intracanal visualization.
        J Endod. 2001; 27: 128-129
        • Nair P.N.
        On the causes of persistent apical periodontitis: a review.
        Int Endod J. 2006; 39: 249-281
        • Crozeta B.M.
        • de Sousa-Neto M.D.
        • Leoni G.B.
        • et al.
        A micro-computed tomography assessment the efficacy of rotary and reciprocating techniques for filling material removal in root canal retreatment.
        Clin Oral Investig. 2016; 20: 2235-2240
        • Martins M.P.
        • Duarte M.A.
        • Cavenago B.C.
        • et al.
        Effectiveness of the ProTaper next and reciproc systems in removing root canal filling material with sonic or ultrasonic irrigation: a micro-computed tomographic study.
        J Endod. 2017; 43: 467-471
        • Hülsmann M.
        • Bluhm V.
        Efficacy, cleaning ability and safety of different rotary NiTi instruments in root canal retreatment.
        Int Endod J. 2004; 37: 468-476
        • Rached-Junior F.A.
        • Sousa-Neto M.D.
        • Bruniera J.F.B.
        • et al.
        Confocal microscopy assessment of filling material remaining on root canal walls after retreatment.
        Int Endod J. 2014; 47: 264-270
        • Keleş A.
        • Keskin C.
        Deviations of mesial root canals of mandibular first molar teeth at the apical third: a micro-computed tomographic study.
        J Endod. 2018; 44: 1030-1032
        • Carr G.B.
        • Murgel C.A.F.
        The use of the operating microscope in endodontics.
        Dent Clin North Am. 2010; 54: 191-214
        • Kfir A.
        • Tsesis I.
        • Yakirevich E.
        • et al.
        The efficacy of five techniques for removing root filling material: microscopic versus radiographic evaluation.
        Int Endod J. 2012; 45: 35-41
        • Detsch S.G.
        • Cunningham W.T.
        • Langloss J.M.
        Endoscopy as an aid to endodontic diagnosis.
        J Endod. 1979; 5: 60-62
        • Engelke W.G.H.
        In situ examination of implant sites with support immersion endoscopy.
        Int J Oral Maxillofac Implants. 2002; 17: 703-706
        • Bahcall J.K.
        • DiFiore P.M.
        • Poulakidas T.K.
        An endoscopic technique for endodontic surgery.
        J Endod. 1999; 25: 132-135
        • Keleş A.
        • Arslan H.
        • Kamalak A.
        • et al.
        Removal of filling materials from oval-shaped canals using laser irradiation: a micro–computed tomographic study.
        J Endod. 2015; 41: 219-224
        • Keles A.
        • Keskin C.
        • Alqawasmi R.
        • et al.
        Diagnostic accuracy of endoscopy for the detection of isthmuses of mandibular molar teeth using micro-CT as reference.
        Eur Oral Res. 2021; 55: 34-38