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Updated: Jan 11, 2026
Precision of In Vivo Quantitative Tooth Wear Measurement Using Intra-Oral Scans
Published on: July 12, 2022
Quantitative evaluation of interproximal contact tightness under functional loading based on digital scanning: An in
Hongyan Wang1, Li Gao2, Sukun Tian3
1Doctoral student, Institute of Medical Technology, Peking University Health Science Center, Beijing, PR China.
Statement Of Problem:
The reliability and validity of intraoral scanning technology to quantitatively analyze interproximal contact tightness (ICT) under functional loading remain insufficiently established.
Purpose:
The purpose of this clinical study was to evaluate the consistency of the method among operators to determine reliability. Additionally, the effects of varying occlusal force and jaw position on ICT change and potential interactions between these 2 factors were evaluated.
Material And Methods:
Twenty participants (10 men and 10 women, mean ±standard deviation age 27.75 ±4.45 years) were recruited to engage in light and heavy occlusal control training using the T-Scan Novus system and intraoral 3-dimensional (3D) scanning with the Aoralscan 3 scanner. The surface data of the bilateral posterior teeth in both the maxillary and mandibular arch, as well as light and heavy bilateral buccal occlusal data, were collected for each participant. The data were imported into Geomagic to establish a local coordinate system (X: mesiodistal, MD; Y: buccolingual, BL; Z: occluso-gingival, OG), segment the first and second molars (target teeth), create feature lines for interproximal contact areas, perform virtual occlusal registration, convert lines into feature points, and analyze the average distance changes of bilateral feature points. These represented the ICT changes (including total change Dm and each axis change Dx, Dy, and Dz) of target teeth under functional loading. Interoperator consistency was assessed by the intraclass correlation coefficient (ICC). Differences in ICT change with factors of occlusal force and jaw position were analyzed using the 2-way repeated measures ANOVA (α=.05).
Results:
Whether the occlusal force was light or heavy, the ICC values among the 3 operators ranged from 0.800 to 0.961. The main effect of occlusal force was significant in total change and each axis change (all P<.01, η²p=.390 to.739), indicating greater ICT change under heavy occlusal force. The main effect of jaw position was significant only in the OG direction (P=.013, η²p=.285), with greater ICT change in the maxillary. No significant interaction between occlusal force and jaw position was observed (all P>.207).
Conclusions:
The digital method tested demonstrated good reliability and validity, providing an applicable approach for the quantitative evaluation of ICT changes under functional loading.
