Development of New Artificial Teeth for Caries Removal Training

Objectives: In recent years, the importance of careful caries removal in clinical treatment has been recognized by spreading the conception of minimal intervention (MI) widely. Practically, carious lesions are removed carefully by utilizing hardness, color and stainability using caries detecting dye solution as a guide. For the improvement of educational effect regarding caries removal skills, we developed new artificial teeth in which artificial carious lesions having stainability by caries detecting dye solution were embedded. The aim of this study was to evaluate its suitability as a tooth used in basic training in Operative Dentistry.

Methods: Vickers hardness of each part in the artificial tooth no.26 (Nissin Dental Products) was measured. Eighteen instructors and twenty two students in pre-clinical courses removed carious lesions of the teeth using steel round bars (Mani) and caries detecting dye solution (Caries Check, Nishika). The frequency of application of dye solution and time required for complete removal of the lesions were measured. Then, an anonymous questionnaire was given to them.

Results: Vickers hardness of enamel (composite-resin), sound dentin (epoxy-resin) and carious dentin (PMMA, MMA and diatomic earth) was 95.3, 34.7 and 4.7, respectively (N=5). In the questionnaire, many instructors answered regarding carious lesions, “Feeling of cutting was slightly soft.” “Color was slightly light.” “Configuration and size were appropriate.” and “The lesion was somewhat hard to dye.” Many students answered “The artificial teeth were helpful in understanding caries structure and characteristics.” In instructors and students, the frequency was an average of 4.4 and 6.7 times respectively and time was an average of 5 and 14min, respectively, suggesting suitability for training.

Conclusion: Employment of newly developed artificial teeth to training is effective for dental students to acquire caries removal skills although further improvement is needed in the teeth.

Supported by grant-in-aid for scientific research (A) 16209055 in Japan.