Comparing the reliability of inter- and intra-grader using digital scanning vs. traditional visual method for evaluating preclinical class II composite preparation

Objective

This study aimed to evaluate the intra- and inter-grader reliability of four evaluators using three different digital intraoral scanners and visual methods for typodontic Class II composite preparations.

Materials and methods

Ninety-five typodont teeth of Class II composite preparations were evaluated using traditional visual grading methods (VGM) and digital grading methods (DGM) using the same rubric. Three intraoral scanners were used to scan the Class II cavity preparation for the composite: i700 (Medit, Korea), Trios 4 (3Shape, Denmark), and Shinning 3D (Shinning 3D, China). The same rubric was used to score the visual and digital evaluations by calibrated examiners. Two-way ANOVA was used to compare method- and evaluator-based scores, accounting for the scanner type used.

Results

The scores of the prepped typodont teeth were subjected to an interaction between the examiner and the evaluation technique. In addition, the mean total prepped teeth scores differed between examiners using VGM. A statistically significant interaction emerged between examiners and the evaluation technique employed to assess the total score of the prepped teeth: F(9, 1504) = 3.893, P = 0.001, partial η2 = 0.023. The total prepped tooth score differed between the VGM and DGM groups. Lower (P < 0.05) intra-grader consistency was observed for the final scores when Class II preparations were evaluated using the VGM; however, this consistency improved when using the DGM.

Conclusion

Examiners and evaluation methods affect student performance in Class II cavity preparations. The DGM may be more reliable and consistent within and between evaluators than the VGM is.