Reliability and Validity of T‐scan and 3D Intraoral Scanning for Measuring the Occlusal Contact Area

AbstractPurposeTo determine the reliability of T‐scan and 3D intraoral scan techniques for assessing the occlusal contact area (OCA), compared to occlusal registration and also to assess the validity of the techniques.Materials and MethodsThirty‐one dentate adults participated in this cross‐sectional study. T‐scan records were used to measure the OCA at maximum bite force and at 50% of maximum force using the software's bite force selection tool. A second method measured the OCA between 2 virtual models scanned intraorally using a 3D surface scan and considering the occlusal contact at 2 interocclusal distances (0‐100 and 0‐200 µm). The third method measured OCA using occlusal registration at moderate and maximum occlusal force, and considering contact at the 2 interocclusal distances (0‐100 and 0‐200 µm). Images obtained using the 3 methods were analyzed using ImageJ software. Test‐retest reliability was assessed by the intraclass correlation coefficient (ICC) and validity by Pearson correlations.ResultsICCs ranged from 0.56 to 0.79 (p < 0.001) for the T‐scan; 0.37 to 0.61 (p < 0.05) for 3D surface scan; and 0.92 to 0.95 (p < 0.0005) for occlusal registration. The highest OCA values were obtained using the T‐scan, and the lowest using the 3D surface scan. Occlusal registration measurements had the highest correlations with those of the other techniques.ConclusionsT‐scan is a reliable method for measuring the OCA, but the 3D surface scan is not. Occlusal registration showed a high validity.