Influence of scan extension on the accuracy of maximum intercuspal position recorded by using intraoral scanners or an artificial intelligence-based program.

Abstract

Statement of problem: Intraoral scanners (IOSs) and artificial intelligence (AI) based programs can be used to locate the maximum intercuspal position (MIP). However, the influence of scan extension on the accuracy of the MIP located by using these technologies is uncertain.

Purpose: The purpose of this in vitro study was to analyze the effect of scan extension on the accuracy of the MIP located by using 3 IOSs and an AI-based program.

Material and methods: Stone casts mounted in an articulator in MIP were digitized (T710). Two groups were created: complete- (CA group) and half arch (HA group) scan. In the CA-group, complete arch scans of the reference casts were captured with each IOS tested. The nonarticulated scans were duplicated 20 times. In the HA-groups, the right half arch scans of the reference casts were captured with each IOS tested. Six subgroups were generated: 3 IOS (Primescan-IOS, i700-IOS, and Aoralscan3-IOS) and 3 AI (Primescan-AI, i700-AI, and Aoralscan3-AI) subgroups. In the CA-Primescan-IOS subgroup, 10 duplicated scans were articulated in MIP by recording a bilateral occlusal record. In the CA-Primescan-AI subgroup, 10 duplicated scans were articulated in MIP by using an AI-based program (Bitefinder). In the CA-i700-IOS, CA-Aoralscan3-IOS, CA-i700-AI, and CA-Aoralscan3-AI subgroups, the same procedures as in the CA-Primescan-IOS and CA-Primescan-AI subgroups were completed, respectively. In the HA-Primescan-IOS subgroup, 10 duplicated scans were articulated in MIP by capturing a right occlusal record. In the HA-Primescan-AI subgroup, 10 duplicated scans were articulated in MIP by using the AI-based program. In the HA-i700-IOS, HA-Aoralscan3-IOS, HA-i700-AI, and HA-Aoralscan3-AI subgroups, the same procedures as in the HA-Primescan-IOS subgroups were completed, respectively. A program (Geomagic) was used to calculate 36 interlandmark measurements on the virtual articulated casts (control) and each specimen. Three-way ANOVA and Tukey tests were used to analyze trueness (α=.05). The Levene and pairwise multiple comparison tests were used to analyze precision (α=.05).

Results: MIP trueness discrepancies were found between the IOS (P<.001), groups (P<.001), and subgroups (P<.001), with a significant interaction IOS×subgroup (P<.001), group×subgroup (P<.001), and IOS×group×subgroup (P<.001). The Primescan and i700 (P=.014) and the Primescan and Aoralscan3 (P<.001) were different from each other. The CA and HA groups (P<.001) were different from each other. The IOS and AI subgroups (P<.001) were different from each other. The Levene test showed significant precision discrepancies between the groups (P<.001) and subgroups (P<.001). The HA scans demonstrated significantly worse precision than the CA scans (P<.001). Additionally, the AI-based program obtained significantly worse precision than the IOS programs tested (P<.001).

Conclusions: Scan extension and program impacted the trueness and precision of the MIP. CA groups demonstrated better MIP trueness and worse precision than the HA groups. Primescan obtained better MIP trueness than the i700 and Aoralscan3 systems. The IOSs revealed better MIP trueness and precision than the AI-based program tested.