Accuracy of digital and conventional systems in locating occlusal contacts: A clinical study

Abstract

The accuracy of methods used for locating occlusal contacts throughout the entire clinical procedure has been poorly studied. The purpose of this clinical study was to determine the reproducibility and criterion validity for different methods of locating occlusal contacts. Thirty-two adults with natural dentitions participated in this cross-sectional test-retest study. In total, occlusal contacts at maximum intercuspation were recorded by using 15 methods: silicone transillumination with Occlufast Rock (40, 50, 100, and 200µm) and Occlufast CAD (40 and 50µm); virtual occlusion (100, 200, 300, and 400µm); articulating film (12-, 40-, 100-, and 200-µm-thick); and T-Scan III. Images of the occlusal records were scaled and calibrated spatially, and the occlusal contacts of the right posterior mandibular teeth were delimited by using the FIJI software program. Reproducibility was expressed as 95% confidence intervals (95% CI) of the percentage of agreement in the location of the occlusal contacts between images from the test sessions against retest sessions using the same method. Criterion validity was expressed as 95% CI of the percentage of agreement in the location of the occlusal contacts between images from the test sessions against images from Occlufast Rock (criterion standard). Occlufast Rock achieved 85%to 95% agreement in the location of the occlusal contacts between the 2 sessions, whereas Occlufast CAD, 200-µm articulating film, and T-Scan offered 79%to 86%, 68%to 75%, and 65%to 75% agreement, respectively. The most valid method was Occlufast CAD (74%to 80%) followed by the 200-µm articulating film (57%to 63%), 400-µm virtual occlusion (53%to 62%), 100-µm articulating film (52%to 60%), and T-Scan (48%to 56%). Conventional methods, such as 100- and 200-µm articulating film and digital methods, including 400µm virtual occlusion and T-Scan, offer sufficient accuracy in locating the occlusal contacts. However, strategies are needed to improve accuracy.