Objective evaluation of abutment tooth preparation for preformed metal crowns for primary molars in Japanese preclinical training

• Published in: Pediatric dental journal 2020-08, Vol.30 (2), p.92-98
• Main Authors: Wakamatsu, Noriko, Okano, Tetsu, Kondo, Tsuguko, Hasegawa, Shinobu, Iinuma, Mitsuo
• Format: Article
• Language: English
• Subjects: 3D grading system; Abutment tooth preparation; Preclinical training; Preformed metal crowns for primary teeth; Teacher grading
• ISSN: 0917-2394; 1880-3997
• DOI: 10.1016/j.pdj.2020.03.002

Evaluation of abutment tooth shape for preformed metal crowns for primary teeth in preclinical training depends on the subjective opinion of the instructor providing the training. Thus, the student's grade will likely vary according to teacher grading. In this study, we explored the potential for objective evaluation by comparing evaluations performed by teaching personnel (teacher grading) of abutment teeth for preformed metal crowns for primary teeth prepared by students at a dental school with evaluation by a three-dimensional (3D) laser morphometric system (system grading). The subjects of the evaluations were 139 abutment teeth for preformed metal crowns for primary teeth that had been prepared by fourth-year students at Asahi University School of Dentistry during preclinical pediatric dentistry training. A tooth prepared by a teacher following instruction criteria was used as the reference tooth, and system grade points were calculated from deductions made for insufficient and excessive cutting. Teacher grade points varied among teachers. We found that teachers prioritized contours of the margin, buccal and lingual sides, and adjacent surfaces in their evaluations. System grading showed that most students carried out insufficient cutting. The mean (SD) teacher and system grade points were 57.7 (9.7) and 75.7 (4.7), respectively, and these grade points were positively correlated (r = 0.500). System grading provides a simple 3D visual assessment of insufficient and excessive cutting that can be used for instructing students.