Evaluation of the accuracy of 7 digital scanners: An in vitro analysis based on 3‐dimensional comparisons

Statement of problem. As digital impressions become more common and more digital impression systems are released onto the market, it is essential to systematically and objectively evaluate their accuracy. Purpose. The purpose of this in vitro study was to evaluate and compare the trueness and precision of 6 intraoral scanners and 1 laboratory scanner in both sextant and complete‐arch scenarios. Furthermore, time of scanning was evaluated and correlated with trueness and precision. Material and methods. A custom complete‐arch model was fabricated with a refractive index similar to that of tooth structure. Seven digital impression systems were used to scan the custom model for both posterior sextant and complete arch scenarios. Analysis was performed using 3‐dimensional metrology software to measure discrepancies between the master model and experimental casts. Results. Of the intraoral scanners, the Planscan was found to have the best trueness and precision while the 3Shape Trios was found to have the poorest for sextant scanning (P<.001). The order of trueness for complete arch scanning was as follows: 3Shape D800 >iTero >3Shape TRIOS 3 >Carestream 3500 >Planscan >CEREC Omnicam >CEREC Bluecam. The order of precision for complete‐arch scanning was as follows: CS3500 >iTero >3Shape D800 >3Shape TRIOS 3 >CEREC Omnicam >Planscan >CEREC Bluecam. For the secondary outcome evaluating the effect time has on trueness and precision, the complete‐ arch scan time was highly correlated with both trueness (r=0.771) and precision (r=0.771). Conclusions. For sextant scanning, the Planscan was found to be the most precise and true scanner. For complete‐arch scanning, the 3Shape Trios was found to have the best balance of speed and accuracy.

[1]  Revised American Dental Association Specification no. 19 for Non-aqueous, Elastomeric Dental Impression Materials. , 1977, Journal of the American Dental Association.

[2]  J. Katsoulis,et al.  Impact of digital intraoral scan strategies on the impression accuracy using the TRIOS Pod scanner. , 2016, Quintessence international.

[3]  T. Joyce,et al.  Validation of an optical system to measure acetabular shell deformation in cadavers , 2014, Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine.

[4]  Markus B Blatz,et al.  Influence of impression material and time on the 3-dimensional accuracy of implant impressions. , 2007, Quintessence international.

[5]  W. Johnston,et al.  Detail reproduction, contact angles, and die hardness of elastomeric impression and gypsum die material combinations. , 2000, The International journal of prosthodontics.

[6]  Alfred A Bartolucci,et al.  Effect of imaging powder and CAD/CAM stone types on the marginal gap of zirconia crowns. , 2015, Journal of the American Dental Association.

[7]  Ana Maria Spohr,et al.  In vivo Study of the Accuracy of Dual-arch Impressions. , 2014, Journal of international oral health : JIOH.

[8]  Heike Rudolph,et al.  Computer-aided analysis of the influence of digitizing and surfacing on the accuracy in dental CAD/CAM technology , 2007, Comput. Biol. Medicine.

[9]  Wael Att,et al.  Precision of Dental Implant Digitization Using Intraoral Scanners. , 2016, The International journal of prosthodontics.

[10]  Jin-Hun Jeon,et al.  Accuracy of complete-arch model using an intraoral video scanner: An in vitro study. , 2016, The Journal of prosthetic dentistry.

[11]  Martin F. Land,et al.  Contemporary Fixed Prosthodontics , 1988 .

[12]  Tiegen Liu,et al.  Measurement of the refractive index of human teeth by optical coherence tomography. , 2009, Journal of biomedical optics.

[13]  Tabea V Flügge,et al.  Precision of intraoral digital dental impressions with iTero and extraoral digitization with the iTero and a model scanner. , 2013, American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics.

[14]  A A Caputo,et al.  Effects of disinfectants on dimensional accuracy of impression materials. , 1990, The Journal of prosthetic dentistry.

[15]  W. Scarfe,et al.  Comparison of digital scanning and polyvinyl siloxane impression techniques by dental students: instructional efficiency and attitudes towards technology , 2017, European journal of dental education : official journal of the Association for Dental Education in Europe.

[16]  Giuseppe Varvara,et al.  Dimensional accuracy of resultant casts made by a monophase, one-step and two-step, and a novel two-step putty/light-body impression technique: an in vitro study. , 2008, The Journal of prosthetic dentistry.

[17]  Michal Shohat,et al.  A clinical evaluation of fixed partial denture impressions , 2005 .

[18]  R. Nedelcu,et al.  Scanning accuracy and precision in 4 intraoral scanners: an in vitro comparison based on 3-dimensional analysis. , 2014, The Journal of prosthetic dentistry.

[19]  P. Carrotte,et al.  The quality of impressions for crowns and bridges received at commercial dental laboratories , 1997, British Dental Journal.

[20]  G J Christensen,et al.  What category of impression material is best for your practice? , 1997, Journal of the American Dental Association.

[21]  E. D. Rekow,et al.  Computer-aided design and fabrication of dental restorations: current systems and future possibilities. , 2006, Journal of the American Dental Association.

[22]  R. Storer,et al.  An investigation of methods available for sterilising impressions , 1981, British Dental Journal.

[23]  Bernd Wöstmann,et al.  Accuracy of impressions obtained with dual-arch trays. , 2009, The International journal of prosthodontics.

[24]  M. Al-Ali,et al.  The Effects of Disinfectants on Dimensional Accuracy and Surface Quality of Impression Materials and Gypsum Casts , 2009, Journal of clinical medicine research.

[25]  J. R. Green,et al.  A study of the quality of impressions for anterior crowns received at a commercial laboratory , 1993, British Dental Journal.

[26]  P. Vallittu,et al.  Digital Versus Conventional Impressions in Fixed Prosthodontics: A Review , 2018, Journal of prosthodontics : official journal of the American College of Prosthodontists.

[27]  C. Evans,et al.  CAD/CAM technology for implant abutments, crowns, and superstructures. , 2014, The International journal of oral & maxillofacial implants.

[28]  K D Rudd,et al.  Accurate alginate impressions. , 1969, The Journal of prosthetic dentistry.

[29]  Sebastian B. M. Patzelt,et al.  Accuracy of full-arch scans using intraoral scanners , 2014, Clinical Oral Investigations.

[30]  F A Moore.  The dentist and AIDS. , 1988, The Journal of prosthetic dentistry.

[31]  X Lepe,et al.  Dimensional stability and detail reproduction of irreversible hydrocolloid and elastomeric impressions disinfected by immersion. , 1998, The Journal of prosthetic dentistry.

[32]  P L Millstein,et al.  Determining the accuracy of gypsum casts made from type IV dental stone. , 1992, Journal of oral rehabilitation.

[33]  O. Schaefer,et al.  Qualitative and quantitative three-dimensional accuracy of a single tooth captured by elastomeric impression materials: an in vitro study. , 2012, The Journal of prosthetic dentistry.

[34]  Jian Sun,et al.  Comparison of repeatability between intraoral digital scanner and extraoral digital scanner: An in-vitro study. , 2015, Journal of prosthodontic research.

[35]  Gary D. Hack,et al.  Evaluation of the Accuracy of Six Intraoral Scanning Devices: An in-vitro Investigation. , 2015 .

[36]  T. Attin,et al.  In vivo precision of conventional and digital methods for obtaining quadrant dental impressions , 2016, Clinical Oral Investigations.

[37]  Albert Mehl,et al.  Accuracy of complete-arch dental impressions: a new method of measuring trueness and precision. , 2013, The Journal of prosthetic dentistry.

[38]  John M. Powers,et al.  Craig's Restorative Dental Materials , 2012 .

[39]  M. Özcan,et al.  Adhesion of veneering resins to polymethylmethacrylate-based CAD/CAM polymers after various surface conditioning methods , 2013, Acta odontologica Scandinavica.