A novel in vivo method to evaluate trueness of digital impressions

Emad A Albdour,Eman Shaheen,Francesco Guido Mangano,Myrthel Vranckx,Reinhilde Jacobs,Constantinus Politis

doi:10.1186/s12903-018-0580-9

Emad A Albdour, Eman Shaheen + Show 4 more

Open Access

https://doi.org/10.1186/s12903-018-0580-9

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Abstract

BackgroundIntraoral scanners are devices for capturing digital impressions in dentistry. Until now, several in vitro studies have assessed the trueness of digital impressions, but in vivo studies are missing. Therefore, the purpose of this study was to introduce a new method to assess trueness of intraoral scanners and digital impressions in an in vivo clinical set-up.MethodsA digital impression using an intraoral scanner (Trios® 3 Cart wired, 3Shape, Copenhagen, Denmark) and a conventional alginate impression (Cavex Impressional®, Cavex, Haarlem, the Netherlands) as clinical reference were made for two patients assigned for full mouth extraction. A total of 30 teeth were collected upon surgery after impressions making. The gypsum model created from conventional impression and extracted teeth were then scanned in a lab scanner (Activity 885®, SmartOptics, Bochum, Germany). Digital model of the intraoral scanner (DM), digital model of the conventional gypsum cast (CM) and those of the extracted natural teeth (NT) were imported to a reverse engineering software (3-matic®, Materialise, Leuven, Belgium) in which the three models were registered then DM and CM were compared to their corresponding teeth in NT by distance map calculations.ResultsDM had statistically insignificant better trueness when compared to CM for total dataset (p = 0.15), statistically insignificant better trueness for CM when mandibular arches analyzed alone (p = 0.56), while a significantly better DM trueness (p = 0.013) was found when only maxillary arches were compared.ConclusionsOur results show that digital impression technique is clinically as good as or better than the current reference standard for study models of orthognathic surgery patients.

Highlights

Intraoral scanners are devices for capturing digital impressions in dentistry
Focusing on study models made for orthognathic surgery patients, the aim of this study was to introduce a new method to validate the trueness of digital impressions of teeth scanned with an intraoral scanner and conventional impression when compared to the corresponding natural teeth after extraction and scanned with a high resolution scanner in an in vivo clinical set-up
Results of Wilcoxon Matched Pairs Test for comparing conventional model (CM) and digital model (DM) are reported in Table 2, statistically insignificant better trueness for DM compared to CM (P = 0.15) was found when total dataset was analyzed, statistically insignificant better trueness for CM when mandibular arches analyzed alone (p = 0.56)

Summary

Introduction

Intraoral scanners are devices for capturing digital impressions in dentistry. Until now, several in vitro studies have assessed the trueness of digital impressions, but in vivo studies are missing. The purpose of this study was to introduce a new method to assess trueness of intraoral scanners and digital impressions in an in vivo clinical set-up. Conventional impression taking for dental cast preparation is still the clinical reference standard for replicating the intraoral situation [1]. Studying precision in the clinical set up can be done by repeating the scan of the same dentition intraorally multiple times and measure the deviations among these impressions [12, 15]. Assessing clinical trueness is more challenging, since the dimensions of the natural dental structure for which the digital or conventional impressions are made need to be captured accurately to be used as a reference model for comparison [16]

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