Abstract
Purposing to find out, out of various kinds of tooth carving techniques, a technique, intelligible, simple and free from accident, to the students of dental technician training schools, the authors have made comparative studies on the design cut method our school adopted (A), Obana's dessin mode method (B) and the direct carving method (C). In the previous report, the authors made the freshmen study by themselves these 3 kinds of techniques, evaluated their respective products from the overall viewpoints and dimensional errors in comparison with the standard models, and reported the results.
In the present studies, the students are beforehand given guidance manual and demonstration regarding the above-mentioned 3 methods, and their products are evaluated in the same way as of the previous report. The results are as follows:
1. The evaluation points show a tendency to increase in accordance with the increase in the carving frequency.
2. The average evaluation points of products carved by A, B and C methods are respectively 3.30, 3.16 and 3.26.
3. The increase of evaluation points, compared with those of the self-study case, are 1.21 in A, 1.12 in B and 0.82 in C, that is, guidance manual and demonstration show a remarkable effect in A and B, compared with in the C case.
4. The absolute values of dimensional errors of products carved by A, B and C methods are respectively 8.59, 8.95 and 8.50% in average. Again, in all the 3 cases, the absolutevalues of the dimensional errors decrease by 37.3-40.8%, compared with the dimensional errors in the self-study case, 100%.
5. The range of dimensional errors shows a tendency to decrease, compared with in the self-study case, especially remarkable in A and B techniques.
6. The convergence degree of dimensional errors of products to the standard dimension ± 10% shows a tendency to increase, compared with in the self-study case.
