2021 年 1 巻 1 号 p. 77-87
Introduction: In dental education, it has long been essential to master cavity preparation techniques by training with models, both during basic and clinical training before college graduation as well as during clinical practice as dentists. However, the instruction given is subjective depending on the instructor, with variations in instruction contents and evaluations, and it has long been pointed that quantification is difficult. Effective and efficient education and instruction as well as reproducible and objective evaluations are essential. Therefore, this study examined the objective evaluation and grading of Class Ⅱ metal inlay cavity by a computer system using a non-contact high-speed 3-D shape measuring device.
Subjects and methods: Ten dental residents at the Department of Operative Dentistry, Osaka Dental University Hospital were recruited as subjects. A jaw model containing an artificial tooth for training was used to conduct cavity preparation for a mesial Class Ⅱ metal inlay on the mandibular right first molar tooth within 30 minutes. After preparation, an evaluation was conducted by this system and by nine instructors at the Department of Operative Dentistry with 7 to 28 years of clinical experience. A free description column for the evaluation and instruction items was provided as part of the evaluation by instructors. Feedback was given based on the results, and a total of five sessions of cavity preparation were conducted at two-month intervals. Pearson’s correlation coefficient was used in the correlation analysis of the evaluation results.
Results: Reanalysis was conducted by excluding the seven points which had the largest deductions in the evaluation using the measuring device. As a consequence, a significant positive correlation with the number of preparations was observed. There was also a significant positive correlation with the evaluation by instructors. A comparison of the evaluations by the measuring device and by the instructors showed a significant positive correlation.
Conclusion: The measuring device can consistently and objectively evaluate Class Ⅱ metal inlay cavity preparation equivalent to evaluations by multiple instructors with long clinical experience. It was also shown that a curriculum using evaluations by the measuring device and instructors effectively improved the skills of the dental residents. Incorporating evaluation by the measuring device may be an effective method for reducing the burden on instructors and length of the instruction period.
