Mays Keith A, Crisp H Alex, Vos Paul
Dr. Mays is Associate Dean of Academic Affairs, School of Dentistry, University of Minnesota; Dr. Crisp was a dental student, East Carolina University School of Dental Medicine at the time of this study; and Dr. Vos is Professor and Chair, Department of Biostatistics, East Carolina University.
J Dent Educ. 2016 Jan;80(1):100-7.
Traditionally, faculty assessment of preclinical crown preparations occurs by visualizing preparation features. However, contemporary CAD/CAM tools have the ability to more precisely evaluate preparation features, which is beneficial for psychomotor development. Taper is one of the most challenging features to objectively assess. The aim of this study was twofold: first, to validate the software's ability to distinguish differences in taper, and second, to compare traditional faculty assessment with digital assessment of taper. In the study, 30 all-metal crown preparations were created on typodont teeth with varying degrees of axial reduction and placed into three groups based on amount of taper (minimum, moderate, or excessive). Each tooth was scanned with the D4D scanner, and the taper was analyzed using E4D Compare. A second experiment used 50 crown preparations of tooth #19, which were done as a formative exercise. A comparison faculty assessment with CAD/CAM assessments of taper was performed. The results showed that when the taper was varied, E4D Compare was able to distinguish those differences; the Tukey post-hoc test revealed a significant difference (p=0.001). The qualitative analysis comparing faculty grading to CAD/CAM grading demonstrated a trend for CAD/CAM to be more precise. These results suggest that E4D Compare is an effective means of quantitatively measuring the amount of total occlusal convergence or taper on a crown preparation and that digital assessment may be more precise than faculty visual grading.
传统上，临床前牙冠预备的教师评估是通过观察预备特征来进行的。然而，当代的计算机辅助设计/计算机辅助制造（CAD/CAM）工具能够更精确地评估预备特征，这对心理运动发育有益。锥度是最难客观评估的特征之一。本研究的目的有两个：第一，验证该软件区分锥度差异的能力；第二，比较传统教师评估与锥度的数字评估。在该研究中，在具有不同程度轴向缩减的模型牙上制作了30个全金属牙冠预备体，并根据锥度大小（最小、中等或过大）分为三组。每个牙齿用D4D扫描仪进行扫描，并使用E4D Compare分析锥度。第二个实验使用了50个19号牙的牙冠预备体，这些预备体是作为一次形成性练习完成的。对教师评估与CAD/CAM对锥度的评估进行了比较。结果表明，当锥度变化时，E4D Compare能够区分这些差异；Tukey事后检验显示存在显著差异（p = 0.001）。将教师评分与CAD/CAM评分进行比较的定性分析表明，CAD/CAM有更精确的趋势。这些结果表明，E4D Compare是定量测量牙冠预备体上总咬合聚合度或锥度大小的有效手段，并且数字评估可能比教师视觉评分更精确。
