Accuracy of intraoral and extraoral digital data acquisition for dental restorations

Abstract

The computer-aided design (CAD) and computer-aided manufacturing (CAM) process chain for dental restorations starts with taking an impression of the clinical situation. For this purpose, either extraoral digitization of gypsum models or intraoral digitization can be used. Despite the increasing use of dental digitizing systems, there are only few studies on their accuracy. Objective This study compared the accuracy of various intraoral and extraoral digitizing systems for dental CAD/CAM technology.Material and Methods An experimental setup for three-dimensional analysis based on 2 prepared ceramic master dies and their corresponding virtual CAD-models was used to assess the accuracy of 10 extraoral and 4 intraoral optical non-contact dental digitizing systems. Depending on the clinical procedure, 10 optical measurements of either 10 duplicate gypsum dies (extraoral digitizing) or directly of the ceramic master dies (intraoral digitizing) were made and compared with the corresponding CAD-models.Results The digitizing systems showed differences in accuracy. However, all topical systems were well within the benchmark of ±20 µm. These results apply to single tooth measurements.Conclusions Study results are limited, since only single teeth were used for comparison. The different preparations represent various angles and steep and parallel opposing tooth surfaces (incisors). For most digitizing systems, the latter are generally the most difficult to capture. Using CAD/CAM technologies, the preparation angles should not be too steep to reduce digitizing errors. Older systems might be limited to a certain height or taper of the prepared tooth, whereas newer systems (extraoral as well as intraoral digitization) do not have these limitations.

Marginal Adaptation of CAD/CAM All‐Ceramic Crowns Made by Different Impression Methods: A Literature Review

“…To avoid the limitations in conventional impression‐making methods, intraoral scanners could be considered as an alternative; however, there is no evidence indicating the absolute excellence of one method over the other. The advantages and disadvantages of these methods are presented in Table …”

“…The advantages and disadvantages of these methods are presented in Table 1. [10][11][12][13][14][15][16][17][18][19][20][21][22] Regardless of the method used for recording the prepared teeth, one of the important factors necessary for long-term success of a crown is marginal adaptation, which is possible through accurate reproduction of the finish line. [23][24][25] Some studies measured crown adaptation as the absolute marginal gap, indicating the distance between the tooth and restoration at the finish line area.…”

The effect of scanning the palate and scan body position on the accuracy of complete‐arch implant scans

“…Geometrical features on the scan bodies supply information about the implant orientation, angulation, and 3D spatial position within the dental arch . Digital implant scans can be performed directly following a digital workflow using intraoral scan bodies (ISBs) attached to the implants and an intraoral scanner (IOS) to capture the topography of the ISBs and the surrounding oral structures . Digital implant scanning techniques using direct digital workflow have been popular in recent years parallel with the development of various intraoral scanners (IOSs) and their reported advantages .…”

Fabrication of a CAD/CAM monolithic zirconia crown to fit an existing partial removable dental prosthesis

“…The accuracy of dental CAD/CAM systems has been progressively advanced over the past 50 years 10. The precise scanning technique facilitates accurate replication of the contour with minimal adjustment.…”