Journal of Prosthetic Dentistry
Research and Education| Volume 124, ISSUE 6, P762.e1-762.e8, December 2020

Comparison of different intraoral scanning techniques on the completely edentulous maxilla: An in vitro 3-dimensional comparative analysis


      Statement of problem

      Information about the accuracy of intraoral scanners for the edentulous maxilla is lacking.


      The purpose of this in vitro study was to compare the accuracy of 3 different intraoral scanner techniques on a completely edentulous maxilla typodont.

      Material and methods

      Two completely edentulous maxillary typodonts with (wrinkled typodont) and without (smooth typodont) palatal rugae were used as reference and were scanned by using an industrial metrological machine to obtain 2 digital reference scans in standard tessellation language (STL) format (dWT and dST). Three different scanning techniques were investigated: in the buccopalatal technique, the buccal vestibule was scanned with a longitudinal movement ending on the palatal vault with a posteroanterior direction; the S-shaped technique was based on an alternate palatobuccal and buccopalatal scan along the ridge; in the palatobuccal technique, the palate was scanned with a circular movement and then with a longitudinal one along the buccal vestibule. Consecutively, 6 types of scans were obtained (n=10), namely wrinkled typodont/buccopalatal technique, wrinkled typodont/S-shaped technique, wrinkled typodont/palatobuccal technique (wrinkled typodont), smooth typodont/buccopalatal technique, smooth typodont/S-shaped technique, and smooth typodont/palatobuccal technique (smooth typodont). Scans in STL format were imported into a dedicated software program, and trueness and precision were evaluated in μm. In addition to descriptive statistics (95% confidence interval), a 2-factor ANOVA on the data ranks, the Kruskal-Wallis, and the Dunn tests were performed to analyze differences among groups (α=.05).


      Mean values for trueness (95% confidence interval) were wrinkled typodont/buccopalatal technique=48.7 (37.8-59.5); wrinkled typodont/S-shaped technique=65.9 (54.9-77.4); wrinkled typodont/palatobuccal technique=109.7 (96.1-123.4); smooth typodont/buccopalatal technique=48.1 (42.4-53.7); smooth typodont/S-shaped technique=56.4 (43.9-68.9); smooth typodont/palatobuccal technique=61.1 (53.3-69), with statistically significant differences for wrinkled typodont/buccopalatal technique versus wrinkled typodont/palatobuccal technique (P<.001), buccopalatal technique versus palatobuccal technique (P<.001), and wrinkled typodont versus smooth typodont (P=.002). Mean values for precision (95% confidence interval) were wrinkled typodont/buccopalatal technique=46.7 (29.7-63.7); wrinkled typodont/S-shaped technique=53.6 (37.6-69.7); wrinkled typodont/palatobuccal technique=90 (59.1-120.9); smooth typodont/buccopalatal technique=46 (39.7-52.3); smooth typodont/S-shaped technique=76 (55.5-96.6); smooth typodont/palatobuccal technique=52.9 (41.9-63.8); with statistically significant differences for buccopalatal technique versus palatobuccal technique (P=.032) and wrinkled typodont/buccopalatal technique versus wrinkled typodont/palatobuccal technique (P=.012).


      Smooth typodont scans showed better trueness than wrinkled typodont scans. Buccopalatal technique showed better mean values for trueness and precision than palatobuccal technique only in the wrinkled typodont scenario, while the other scanning approaches did not show significant differences in either tested configuration.
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Journal of Prosthetic Dentistry
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Imburgia M.
        • Logozzo S.
        • Hauschild U.
        • Veronesi G.
        • Mangano C.
        • Mangano F.G.
        Accuracy of four intraoral scanners in oral implantology: a comparative in vitro study.
        BMC Oral Health. 2017; 17: 92
        • Bilgin M.S.
        • Baytaroğlu E.N.
        • Erdem A.
        • Dilber E.
        A review of computer-aided design/computer-aided manufacture techniques for removable denture fabrication.
        Eur J Dent. 2016; 10: 286-291
        • Goracci C.
        • Franchi L.
        • Vichi A.
        • Ferrari M.
        Accuracy, reliability, and efficiency of intraoral scanners for full-arch impressions: a systematic review of the clinical evidence.
        Eur J Orthod. 2016; 38: 422-428
        • Yuzbasioglu E.
        • Kurt H.
        • Turunc R.
        • Bilir H.
        Comparison of digital and conventional impression techniques: evaluation of patients' perception, treatment comfort, effectiveness and clinical outcomes.
        BMC Oral Health. 2014; 14: 10
        • Burhardt L.
        • Livas C.
        • Kerdijk W.
        • van der Meer W.J.
        • Ren Y.
        Treatment comfort, time perception, and preference for conventional and digital impression techniques: a comparative study in young patients.
        Am J Orthod Dentofacial Orthop. 2016; 150: 261-267
        • Grünheid T.
        • McCarthy S.D.
        • Larson B.E.
        Clinical use of a direct chairside oral scanner: an assessment of accuracy, time, and patient acceptance.
        Am J Orthod Dentofac Orthop. 2014; 146: 673-682
        • Schepke U.
        • Meijer H.J.
        • Kerdijk W.
        • Cune M.S.
        Digital versus analog complete arch impressions for single-unit premolar implant crowns: operating time and patient preference.
        J Prosthet Dent. 2015; 114: 403-406
        • Sakornwimon N.
        • Leevailoj C.
        Clinical marginal fit of zirconia crowns and patients' preferences for impression techniques using intraoral digital scanner versus polyvinyl siloxane material.
        J Prosthet Dent. 2017; 118: 386-391
        • Lee S.J.
        • Gallucci G.O.
        Digital vs. conventional implant impressions: efficiency outcomes.
        Clin Oral Implants Res. 2013; 24: 111-115
        • Joda T.
        • Bragger U.
        Time-efficiency analysis comparing digital and conventional workflows for implant crowns: a prospective clinical crossover trial.
        Int J Oral Maxillofac Implants. 2015; 30: 1047-1053
        • Joda T.
        • Bragger U.
        Digital vs. conventional implant prosthetic workflows: a cost/time analysis.
        Clin Oral Implants Res. 2015; 26: 1430-1435
        • Patzelt S.B.
        • Lamprinos C.
        • Stampf S.
        • Att W.
        The time efficiency of intraoral scanners: an in vitro comparative study.
        J Am Dent Assoc. 2014; 145: 542-551
        • Joda T.
        • Lenherr P.
        • Dedem P.
        • Kovaltschuk I.
        • Bragger U.
        • Zitzmann N.U.
        Time efficiency, difficulty, and operator's preference comparing digital and conventional implant impressions: a randomized controlled trial.
        Clin Oral Implants Res. 2017; 28: 1318-1323
        • Mangano F.
        • Gandolfi A.
        • Luongo G.
        • Logozzo S.
        Intraoral scanners in dentistry: a review of the current literature.
        BMC Oral Health. 2017; 17: 149
        • Al Hamad K.Q.
        Learning curve of intraoral scanning by prosthodontic residents.
        J Prosthet Dent. 2020; 123: 277-283
        • Patzelt S.B.
        • Vonau S.
        • Stampf S.
        • Att W.
        Assessing the feasibility and accuracy of digitizing edentulous jaws.
        J Am Dent Assoc. 2013; 144: 914-920
        • Andriessen F.S.
        • Rijkens D.R.
        • Van der Meer W.J.
        • Wismeijer D.W.
        Applicability and accuracy of an intraoral scanner for scanning multiple implants in edentulous mandibles: a pilot study.
        J Prosthet Dent. 2014; 111: 186-194
        • Bidra A.S.
        • Taylor T.D.
        • Agar J.R.
        Computer-aided technology for fabricating complete dentures: systematic review of historical background, current status, and future perspectives.
        J Prosthet Dent. 2013; 109: 361-366
        • Patzelt S.B.
        • Emmanouilidi A.
        • Stampf S.
        • Strub J.R.
        • Att W.
        Accuracy of full-arch scans using intraoral scanners.
        Clin Oral Investig. 2014; 18: 1687-1694
        • Nedelcu R.
        • Olsson P.
        • Nyström I.
        • Thor A.
        Finish line distinctness and accuracy in 7 intraoral scanners versus conventional impression: an in vitro descriptive comparison.
        BMC Oral Health. 2018; 18: 27
        • Abduo J.
        • Elseyoufi M.
        Accuracy of intraoral scanners: a systematic review of influencing factors.
        Eur J Prosthodont Restor Dent. 2018; 26: 101-121
        • Kim J.E.
        • Amelya A.
        • Shin Y.
        • Shim J.S.
        Accuracy of intraoral digital impressions using an artificial landmark.
        J Prosthet Dent. 2017; 117: 755-761
        • Lo Russo L.
        • Salamini A.
        Removable complete digital dentures: a workflow that integrates open technologies.
        J Prosthet Dent. 2018; 119: 727-732
        • Chochlidakis K.M.
        • Papaspyridakos P.
        • Geminiani A.
        • Chen C.J.
        • Feng I.J.
        • Ercoli C.
        Digital versus conventional impressions for fixed prosthodontics: a systematic review and meta-analysis.
        J Prosthet Dent. 2016; 116: 184-190
        • Bohner L.
        • Gamba D.D.
        • Hanisch M.
        • Marcio B.S.
        • Tortamano Neto P.
        • Laganá D.C.
        • et al.
        Accuracy of digital technologies for the scanning of facial, skeletal, and intraoral tissues: a systematic review.
        J Prosthet Dent. 2019; 121: 246-251
        • Flügge T.V.
        • Att W.
        • Metzger M.C.
        • Nelson K.
        Precision of dental implant digitization using intraoral scanners.
        Int J Prosthodont. 2016; 29: 277-283
        • Lo Russo L.
        • Caradonna G.
        • Troiano G.
        • Salamini A.
        • Guida L.
        • Ciavarella D.
        Three-dimensional differences between intraoral scans and conventional impressions of edentulous jaws: a clinical study.
        J Prosthet Dent. 2020; 123: 264-268
        • Lo Russo L.
        • Salamini A.
        Single-arch digital removable complete denture: a workflow that starts from the intraoral scan.
        J Prosthet Dent. 2018; 120: 20-24
        • Gan N.
        • Xiong Y.
        • Jiao T.
        Accuracy of intraoral digital impressions for whole upper jaws, including full dentitions and palatal soft tissues.
        PLoS One. 2016; 11: e0158800
        • Lee J.H.
        Improved digital impressions of edentulous areas.
        J Prosthet Dent. 2017; 117: 448-449
        • Fang J.H.
        • An X.
        • Jeong S.M.
        • Choi B.H.
        Digital intraoral scanning technique for edentulous jaws.
        J Prosthet Dent. 2018; 119: 733-735
        • Goodacre B.J.
        • Goodacre C.J.
        • Baba N.Z.
        Using intraoral scanning to capture complete denture impressions, tooth positions, and centric relation records.
        Int J Prosthodont. 2018; 31: 377-381
        • Fang Y.
        • Fang J.H.
        • Jeong S.M.
        • Choi B.H.
        A technique for digital impression and bite registration for a single edentulous arch.
        J Prosthodont. 2019; 28: 519-523
        • Fang J.H.
        • An X.
        • Jeong S.M.
        • Choi B.H.
        Development of complete dentures based on digital intraoral impressions-case report.
        J Prosthodont Res. 2018; 62: 116-120
        • Müller P.
        • Ender A.
        • Joda T.
        • Katsoulis J.
        Impact of digital intraoral scan strategies on the impression accuracy using the TRIOS Pod scanner.
        Quintessence Int. 2016; 47: 343-349
        • Medina-Sotomayor P.
        • Pascual-Moscardó A.
        • Camps I.
        Accuracy of four digital scanners according to scanning strategy in complete-arch impressions.
        PLoS One. 2018; 13: e0202916
        • Latham J.
        • Ludlow M.
        • Mennito A.
        • Kelly A.
        • Evans Z.
        • Renne W.
        Effect of scan pattern on complete-arch scans with 4 digital scanners.
        J Prosthet Dent. 2020; 123: 85-95
        • Park G.H.
        • Son K.
        • Lee K.B.
        Feasibility of using an intraoral scanner for a complete-arch digital scan.
        J Prosthet Dent. 2019; 121: 803-810
        • Mandelli F.
        • Gherlone E.
        • Keeling A.
        • Gastaldi G.
        • Ferrari M.
        Full arch intraoral scanning: comparison of two different strategies and their accuracy outcomes.
        J Osseointegr. 2018; 10: 65-74
        • Chebib N.
        • Kalberer N.
        • Srinivasan M.
        • Maniewicz S.
        • Perneger T.
        • Müller F.
        Edentulous jaw impression techniques: an in vivo comparison of trueness.
        J Prosthet Dent. 2019; 121: 623-660
        • D’Arienzo L.F.
        • D’Arienzo A.
        • Borracchini A.
        Comparison of the suitability of intra-oral scanning with conventional impression of edentulous maxilla in vivo. A preliminary study.
        J Osseointegr. 2018; 10: 115-120
        • Nedelcu R.
        • Olsson P.
        • Nyström I.
        • Rydén J.
        • Thor A.
        Accuracy and precision of 3 intraoral scanners and accuracy of conventional impressions: a novel in vivo analysis method.
        J Dent. 2018; 69: 110-118
        • Treesh J.C.
        • Liacouras P.C.
        • Taft R.M.
        • Brooks D.I.
        • Raiciulescu S.
        • Ellert D.O.
        • et al.
        Complete-arch accuracy of intraoral scanners.
        J Prosthet Dent. 2018; 120: 382-388
        • Ender A.
        • Zimmermann M.
        • Mehl A.
        Accuracy of complete- and partial-arch impressions of actual intraoral scanning systems in vitro.
        Int J Comput Dent. 2019; 22: 11-19
        • Mangano F.G.
        • Hauschild U.
        • Veronesi G.
        • Imburgia M.
        • Mangano C.
        • Admakin O.
        Trueness and precision of 5 intraoral scanners in the impressions of single and multiple implants: a comparative in vitro study.
        BMC Oral Health. 2019; 19: 101
        • Mangano F.G.
        • Veronesi G.
        • Hauschild U.
        • Mijiritsky E.
        • Mangano C.
        Trueness and precision of four intraoral scanners in oral implantology: a comparative in vitro study.
        PLoS One. 2016; 11: e0163107
        • Mandelli F.
        • Gherlone E.
        • Gastaldi G.
        • Ferrari M.
        Evaluation of the accuracy of extraoral laboratory scanners with a single-tooth abutment model: a 3D analysis.
        J Prosthodont Res. 2017; 61: 363-370
        • Zarone F.
        • Ruggiero G.
        • Di Mauro M.I.
        • Spagnuolo G.
        • Ferrari M.
        • Sorrentino R.
        Accuracy of three impression materials on the totally edentulous maxilla: in vitro/in silico comparative analysis.
        Materials (Basel). 2020; 13: 515
        • International Organization for Standardization
        ISO 5725-1. Accuracy (trueness and precision) of measurement methods and results. Part 1: general principles and definitions.
        International Organization for Standardization, Berlin1994 (Available at:)
        • Sim J.Y.
        • Jang Y.
        • Kim W.C.
        • Kim H.Y.
        • Lee D.H.
        • Kim J.H.
        Comparing the accuracy (trueness and precision) of models of fixed dental prostheses fabricated by digital and conventional workflows.
        J Prosthodont Res. 2019; 63: 25-30