Three‐Dimensional Static Articulation Accuracy of Virtual Models – Part I: System Trueness and Precision

Purpose To study the effects of altering condylar settings and pin openings on the trueness and precision of virtual articulators vs. mechanical articulators. Materials and Methods Maxillary and mandibular typodonts with fiducial markers were mounted on a mechanical Artex‐CR articulator, and the mandibular teeth were prepared to allow guidance solely by the posterior determinants of the articulator and the incisal table. The relationship of the mounted typodonts was preserved digitally by scanning using manufacturer transfer plate adaptors. On the mechanical articulator, pattern resin was allowed to set between the maxillary and mandibular occlusal surfaces (area #25‐30) at the endpoints of dynamic movements at 3 condylar inclinations (SCI): 10°, 30°, and 45°, n = 12/inclination, or at 3 incisal pin openings (2, 5, and 10 mm, n = 12/opening). All other articulator settings were kept constant. Resin specimens attached to the typodonts were scanned within 5 minutes of setting, then removed, and the articulated typodonts rescanned. Fixed dental prostheses (FDPs) #25‐30 were designed on the virtual articulator using identical parameters to the mechanical articulator. Dynamic virtual movements were used to sculpt the design, and a file of the design was saved. The files of both types of samples were aligned and overlaid. Interocclusal separation was measured in triplicate at the indentation created by the mesiolabioincisal point angle on the incisal edge of #8 and the mesiobucco‐occlusal point angle of #3. Trueness and precision of both types of articulators were calculated and compared using one‐way ANOVA, followed by the Tukey HSD test (α = 0.05). Results There was no statistically significant difference at altered pin openings in either trueness (F = 0.202, p = 0.37) or precision (F = 3.134, p = 0.09) for the majority of measurements. The only significant difference was in the precision between the 2 types of articulators at 5 mm incisal opening, and only at the anterior measurement point (F = 15.134, p = 0.0008); however, these differences were less than 100 μm. When the SCI was altered, there was no statistically significant difference (F = 3.624, p > 0.05) between the virtual and mechanical articulators in trueness for 5 of the 6 measurements obtained (F = 3.624, p = 0.07) or for all of the precision measurements (F = 3.529, p = 0.07). The one trueness measurement that was significantly different (F = 9.237, p = 0.006) occured at SCI of 10°, and it was less than 100 µm. Conclusions Dynamic movements on the virtual articulator were shown to be as true and precise as to the mechanical articulator. When there were deviations, these deviations were less than 100 µm and thus, these deviations may not be clinically relevant.

mentioning

confidence: 99%

Accuracy of Dynamic Virtual Articulation: Trueness and Precision

Hsu

Driscoll

Romberg

et al. 2019

“…In another study by the same group, two virtual articulation methods were investigated: conventional mounting and interocclusal record articulation. The authors concluded that interocclusal records resulted in decreased interarch and interocclusal distances predisposing toward infra‐occluded prostheses, whereas mounted models were associated with increased interarch and interocclusal distances 35,36 …”

Section: Step 2: Accurate Occlusal Registration In Maximum Intercuspamentioning

confidence: 99%

Virtual Articulators and Virtual Mounting Procedures: Where Do We Stand?

Lepidi

Galli

Mastrangelo

et al. 2020

112

A virtual articulator is a computer software tool that is capable of reproducing the relationship between the jaws and simulating jaw movement. It has gradually gained research interest in dentistry over the past decade. In prosthodontics, the virtual articulator should be considered as an additional diagnostic and treatment planning tool to the mechanical articulator, especially in complex cases involving alterations to the vertical dimension of occlusion. Numerous authors have reported on the available digital methodologies used for the assembly of virtual arch models in a virtual articulator, focusing their attention on topics such as the virtual facebow and digital occlusal registration. To correctly simulate jaw movement, the jaw models have to be digitalized and properly mounted on the virtual articulator. The aim of this review was to discuss the current knowledge surrounding the various techniques and methodologies related to virtual mounting in dentistry, and whether virtual articulators will become commonplace in clinical practice in the future. This review also traces the history of the virtual articulator up to its current state and discusses recently developed approaches and workflows for virtual mounting based on current knowledge and technological devices.

“…Digital workflows can be divided into 2 methods: scanning casts using a desktop scanner or scanning directly within the patient's oral cavity using an intraoral scanner . The former method involves the error of impression and gypsum materials because casts are fabricated through conventional impressions . However, because it scans outside the mouth, it is stable and high accuracy scan data can be obtained through the desktop scanner .…”

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confidence: 99%

“…The former method involves the error of impression and gypsum materials because casts are fabricated through conventional impressions . However, because it scans outside the mouth, it is stable and high accuracy scan data can be obtained through the desktop scanner . The latter method is not affected by impression and stone materials because it uses an intraoral scanner, and scan data can be obtained faster .…”

mentioning

confidence: 99%

Displacement of Customized Abutments Designed on a Working Cast and in the Oral Cavity: A Comparative In Vivo Study

Lee

2019

Purpose: To compare abutment displacement between the virtual, customized abutment that was designed on a cast and the customized abutment prepared in the oral cavity. Materials and Methods: Eleven patients were selected for a single posterior implant prosthetic treatment. The impression was obtained using the closed tray impression method with a vinyl polysiloxane material using a custom tray. The standard tessellation language files of the customized abutment that was designed using the computer-aided design system and acquired with an intraoral scanner in the oral cavity were superimposed and analyzed for distance and angle displacement using the three-dimensional inspection analysis program (Geomagic Control X). In the statistical analysis, distance and angle displacement values were analyzed with the Kruskal-Wallis H test (α = 0.05), and a post hoc comparison was performed using the Mann-Whitney U-test and Bonferroni correction method. Results: The mean distance and angle displacement of the 15 customized abutments were 89.52 ± 66.86 µm and 0.83 ± 1.21°, respectively. There were significant differences in distance displacement (p < 0.001), and angle displacement (p < 0.001) among the 15 customized abutments, and there were no significant differences in angle displacement along the 4 directions (p = 0.735). Conclusions:The displacement values of the customized abutments evaluated in the oral cavity differed significantly from patient to patient.