Visual inspection (VI) of dental student “waxups” by faculty has frequently been challenged as subjective and inconsistent. Traditional grading rubrics fail to precisely assess morphology due to coarse detail and inappropriate application of ratio measurement to ordinal data. The aim of this study was to test the hypothesis that VI would be measurably imprecise and inaccurate and to explore development of a superior digital assessment alternative. In fall 2017, six examiners at one U.S. dental school independently evaluated 81 student waxups of tooth #14 using VI. Grades were awarded using a 20‐item rubric, corresponding to discrete morphologic features. After inclusion criteria were met, 67 waxups were subsequently scanned with an intraoral scanner; analyzed using three‐dimensional surface comparison software; and digitally compared to scans of the same typodonts containing the original tooth #14. Examiner precision and accuracy were evaluated using digital inspection of morphologic regions in the VI rubric. Within this study's limitations, VI exhibited low inter‐examiner precision (ICC 0.332) and accuracy (“correctness”), resulting in potentially low‐grade validity. Intra‐examiner precision for three examiners was low, based on computation of statistically different mean grades (single tail paired t‐test), awarded by the same examiners one week apart. One examiner had to leave the study, for whom paired t‐test could not be performed. Independent digital evaluation by two examiners exhibited high inter‐examiner precision (ICC 0.866) and optimal accuracy. These results affirm the possibility that digital assessment techniques offer improvements in visualization, consistently valid student evaluation, and optimal self‐evaluation and self‐correction.

In Part I of this study, evidence was presented that visual inspection (VI) of dental student waxups exhibited low precision (ICC=0.332) and accuracy, resulting in questionable grade validity. VI inappropriately assesses morphology in part due to oversimpliied grading rubrics and inappropriate application of ratio measurement to ordinal data. The aim of Part II of this study was to develop, apply, and compare with VI a digital assessment worklow and report the outcomes. After inclusion criteria were met, 67 (83%) student waxups were scanned with an intraoral scanner and analyzed using open source surface comparison software. Each was digitally compared to the homologous standard typodont tooth. Percentage contour variation within a stipulated tolerance was computed. The acceptable tolerance was derived from clinical literature reporting how contour deviations impact the biological and biomechanical stability of teeth and periodontium. Surface roughness of each waxup was also computed and compared with the reference teeth. A formula for digital assessment was developed and applied to each waxup. On average, digital grades exceeded the VI assessments, while correcting individual errors for greater accuracy and precision (ICC=0.866). Students were able to easily apply the digital worklow for visualization and accurate self-evaluation. In this study, a digital grading worklow was developed that used portable data formats and freely available open source analysis software, so the method could be introduced at any dental school where intraoral scanning is available.