Reproducibility of Dental Bite Registrations Using A Direct Intraoral Scanner

Abstract

Abstract Aim: The aim of this study was to determine if a direct intraoral scanner is a reliable method to record dental bite registrations. Methods: Intraoral scans and bite registrations were taken on 41 adult patients at an initial time point (T1) and at a second time point (T2), one week later, using the iTero Element intraoral scanner. The difference in the number of teeth with occlusal contacts between the two time points was calculated for each subject using OrthoCAD. Statistical analysis using a paired t-test was performed to analyze the differences in the occlusal contacts from T1 and T2. Results: There was a significant difference in the number of teeth with occlusal contact at the heavy occlusal contact strength of < 0.0mm (2.17, p <0.0001) and at the moderate occlusal contact strength of < 0.2mm (0.59, p= 0.0002), between T1 and T2. When comparing tooth types and individual teeth, all teeth had significant changes in occlusal contacts between T1 and T2, except for the moderate contacts on the premolar tooth type and the moderate contacts on the left posterior premolar and molar individual teeth. There was a significant negative correlation (-0.6) between number of initial contacts and the change of occlusal contacts between T1 and T2. Conclusions: Direct intraoral scanners are not reliable in the capturing of reproducible dental bite registrations for orthodontic treatment planning and case analysis. Soft tissue interferences and changes in patient bite force during acquisition could pose a limitation in the precision of occlusal contacts. Additional studies should be carried out with tissue interferences eliminated and proper instructions given to patients for biting force.