A comparative evaluation between the reliability of gypsum casts and digital greyscale intra-oral scans for the scoring of tooth wear using the Tooth Wear Evaluation System (TWES)

Abstract

Background: The Tooth Wear Evaluation System (TWES) is a type of tooth wear index. To date, there is the lack of data comparing the reliability of the application of this index on gypsum cast records and digital greyscale intra-oral scan records. Objectives: A comparative evaluation between the use of gypsum cast records and digital greyscale intra-oral scan records with the reliability of tooth wear scoring using the TWES amongst a group of patients with tooth wear. Methods: Records for 10 patients with moderate to severe tooth wear (TWES ≥ 2) were randomly selected from a larger clinical trial. TWES grading of the occlusal/incisal, buccal and palatal/lingual surfaces was performed to determine the levels of intra- and interobserver agreement. Intra-observer reproducibility was based on the findings of one examiner only. For the interobserver reproducibility, the findings of two examiners were considered. One set of models/ records were used per patient. Cohen's weighted kappa (κW) was used to ascertain agreement between and within the observers. Comparison of agreement was performed using t tests (P