Statement of problem
Compared with the frequent investigations into the accuracy of digital intraoral scans, studies analyzing digital determinations of jaw relationships based on intraoral scans are scarce.
The purpose of this in vitro study was to present an optical 3-dimensional method for analyzing deviations in static occlusion and to compare the accuracy of conventional and digital interocclusal registrations.
Material and methods
A Frasaco jaw model was duplicated, articulated, and scanned with a high-precision industrial scanner, and the data were stored in a virtual standard tessellation language (STL) format, which served as the reference model. Fifteen paired mandibular and maxillary models were scanned with a digital intraoral scanner in the completely digital workflow (IOS group). Forty-five paired gypsum casts were poured from polyvinyl siloxane (PVS) impressions and associated with 2 different PVS registration materials. These casts were digitized with a laboratory scanner and grouped as follows (n=15/group): PVS group, conventional Futar D interocclusal record; sPVS group, conventional Futar Scan interocclusal record; and the AIR group, partially digital antagonist scan of the Futar Scan interocclusal record. The axes (X, Y, Z, and XYZ) of each paired model were aligned to those of the reference model by 3-dimensional superimposition, and deviations were calculated. To determine the ideal zero position, a best-fit over the mandibular teeth between the reference model and the actual model was estimated. Next, a second best-fit was determined between the maxillary models to determine the actual position of the mandibular model. The different registration methods were compared with the Mann–Whitney U test (α=.05).
In the IOS group, the interocclusal registration caused a mandibular deviation of 0.05 ±0.04 mm (mean ±standard deviation). This fit was better than those of conventional registrations with inserted interocclusal registration materials (PVS group and sPVS group), which caused mean z-axis deviations of 0.41 ±0.46 mm and 0.44 ±0.32 mm (P<.001), with the deviations leading to elevation of the mandibular model. The partially digital workflow with a scannable registration material (AIR group) showed significantly larger deviations in the x-axis (0.15 ±0.08 mm; P=.042) compared with the IOS group. No significant difference was observed in the total deviation between the IOS and the AIR groups. Both groups showed significantly smaller deviations than the conventional registration methods (P<.001 for the IOS group and P=.023 for the AIR group).
In comparison with maxillary and mandibular alignment using conventional interocclusal registration materials, digital interocclusal registrations showed greater accuracy in evaluating complete jaw models and can be recommended for clinical use. Additionally, the partially digital workflow with an antagonist scan of the interocclusal record provided acceptable results.
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- Accuracy of five intraoral scanners compared to indirect digitalization.Clin Oral Investig. 2017; 21: 1445-1455
- Evaluation of the accuracy of interocclusal records in relation to two recording techniques.J Prosthet Dent. 1997; 77: 141-146
- Reliability of recording static and dynamic occlusal contact marks using transparent acetate sheet.J Prosthet Dent. 2005; 94: 458-461
- Impression materials in fixed prosthodontics: influence of choice on clinical procedure.J Prosthodont. 2011; 20: 153-160
- Polyvinyl siloxane impression materials: a review of properties and techniques.J Prosthet Dent. 1992; 68: 728-732
- Comparison of accuracy and reproducibility of casts made by digital and conventional methods.J Prosthet Dent. 2015; 113: 310-315
- Accuracy of complete-arch dental impressions: a new method of measuring trueness and precision.J Prosthet Dent. 2013; 109: 121-128
- Accuracy of complete-arch model using an intraoral video scanner: An in vitro study.J Prosthet Dent. 2016; 115: 755-759
- Accuracy of complete- and partial-arch impressions of actual intraoral scanning systems in vitro.Int J Comput Dent. 2019; 22: 11-19
- A new method for the evaluation of the accuracy of full-arch digital impressions in vitro.Clin Oral Investig. 2016; 20: 1487-1494
- Accuracy of 4 digital scanning systems on prepared teeth digitally isolated from a complete dental arch.J Prosthet Dent. 2019; 121: 811-820
- Three-Dimensional Accuracy of Digital Static Interocclusal Registration by Three Intraoral Scanner Systems.J Prosthodont. 2018; 27: 120-128
- Scanning accuracy and precision in 4 intraoral scanners: an in vitro comparison based on 3-dimensional analysis.J Prosthet Dent. 2014; 112: 1461-1471
- Comparing maximum intercuspal contacts of virtual dental patients and mounted dental casts.J Prosthet Dent. 2002; 88: 622-630
- Comparison of 5 types of interocclusal recording materials on the accuracy of articulation of digital models.Am J Orthod Dentofacial Orthop. 2015; 148: 245-252
- Clinical evaluation of the accuracy of interocclusal recording materials.J Prosthet Dent. 1984; 51: 152-157
- Comparison of a conventional and virtual occlusal record.J Prosthet Dent. 2015; 114: 92-97
- Accuracy and precision of occlusal contacts of stereolithographic casts mounted by digital interocclusal registrations.J Prosthet Dent. 2016; 116: 231-236
- Influence of jaw opening on occlusal vertical dimension between incisors and molars.J Prosthet Dent. 2019; 122: 115-118
- Computer-aided determination of occlusal contact points for dental 3-D CAD.Med Biol Eng Comput. 2006; 44: 445-450
- Clinical accuracy and reproducibility of virtual interocclusal records.J Prosthet Dent. 2020; 124: 667-673
- Precision of the virtual occlusal record.Angle Orthod. 2019; 89: 751-757
- Accuracy of contacts calculated from 3D images of occlusal surfaces.J Dent. 2007; 35: 528-534
- The accuracy of virtual interocclusal registration during intraoral scanning.J Prosthet Dent. 2018; 120: 904-912
- Precision of maxillo-mandibular registration with intraoral scanners in vitro.J Prosthodont Res. 2020; 64: 114-119
- A new triple-scan protocol for 3D fit assessment of dental restorations.Quintessence Int. 2011; 42: 651-657
- Three-dimensional evaluation of mandibular deformation during mouth opening.Int J Comput Dent. 2019; 22: 21-27
Published online: April 19, 2021
© 2021 by the Editorial Council for the Journal of Prosthetic Dentistry.