The Accuracy of Transferring Casts in Maximal Intercuspal Position to a Virtual Articulator

Abstract

Purpose To analyze the accuracy of transferring casts in maximal intercuspal position to a virtual articulator by using transfer plates in the laboratory scanner before and after occlusal optimization. Material and methods Five sets of standard dental casts were mounted on a mechanical articulator in maximal intercuspal position. The number and position of occlusal contacts were determined with 12‐μm articulating foil. After a calibration process according to the manufacturer's instructions, the mountings were transferred to a virtual articulator using the transfer plates in a laboratory scanner. The occlusion of the digital casts was determined before and after the occlusal optimization process. Then, the sensitivity and positive predictive value were determined by comparing the occlusal contact points in the virtual articulator with those in the mechanical articulator. To evaluate trueness, the occlusal surface of the maxillary teeth in the mechanical articulator was recorded by polyvinyl siloxane occlusal record in maximal intercuspal position and retained on the mandibular arch. The trueness was calculated as the deviation between the occlusal surface of the maxillary teeth in the mechanical articulator and the virtual articulator. To evaluate precision, one set of the casts was scanned 10 times. And the deviation of the interarch position of the maxillary arches when superimposing the mandibular arches of every 2 different scans was calculated. Results The sensitivity before occlusal optimization (0.14 ± 0.15) was significantly lower than that after occlusal optimization (0.82 ± 0.10) (p = 0.003). However, there was no significant difference between the positive predictive value before (0.80 ± 0.45) and after (0.81 ± 0.09) occlusal optimization (p = 0.952). The trueness before (91.0 ± 10.7 µm) and after (75.4 ± 25.2 µm) occlusal optimization had no significant difference (p = 0.249). The precision before occlusal optimization (11.6 ± 3.8 µm) was significantly superior to that after occlusal optimization (75.6 ± 39.2 µm ) (p < 0.001). Conclusions The accuracy of transferring casts in maximal intercuspal position to a virtual articulator using transfer plates in the laboratory scanner could be improved after occlusal optimization and can meet the clinical needs for occlusal design and analysis of prostheses.

Effect of a novel interocclusal recording method on occlusal accuracy of implant‐supported fixed prostheses: A randomized clinical trial

“…To quantitatively evaluate the difference in occlusal contacts, diagnostic test was introduced in the 2000s and be commonly used in previous studies to evaluate the accuracy of transferring interocclusal position by different methods, including occlusion obtained by intraoral or extraoral digital scanning, dental casts mounted in articulator (Abdulateef et al, 2020; Fraile et al, 2018; He et al, 2022; Solaberrieta et al, 2015). And intraoral occlusal contact marks are the common gold standard (as reference) which the newer methods are compared to (Sharma et al, 2013).…”

Selecting a Virtual Articulator: An Analysis of the Factors Available with Mechanical Articulators and their Potential Need for Inclusion with Virtual Articulators

“…The most popular is based on the indirect technique in which traditional impressions are poured and the subsequent casts are mounted on an MA, from which a desktop scanner is used to create a digital file. 16 The second method involves intrao-ral scanning of the arches and head position directly to the VA. 8,17,18 What is obvious is that clinician demand and industry innovation is moving toward a highly accurate and all-inclusive digital workflow. It would seem that the future will favor the direct technique.…”

“…Currently, there are two methods to transfer data to a VA. The most popular is based on the indirect technique in which traditional impressions are poured and the subsequent casts are mounted on an MA, from which a desktop scanner is used to create a digital file 16 . The second method involves intraoral scanning of the arches and head position directly to the VA 8,17,18 .…”

A new technique to transfer the upper maxillary arch position using a facebow, a transfer table, and a reference block with a CAD application

“…11 Intraoral scanning is gaining popularity for all types of prosthetic restorations 12 ; however, occlusion scanning and Bonwill's triangle articulation of the cast are insufficient in complex cases. Although there are few published prosthetic clinical reports that use a virtual articulator assembly, 13 there is increased interest in developing mounting techniques for digital casts in a virtual articulator without the necessary steps of articulating gypsum. 14 This study was approved by the ethics committee and written informed consent was provided by the volunteer participants.…”