Abstract
Less skilled students in the tooth carving were divided into two groups with 20 each. One group received a supplemental course with lecture and laboratory exercise and the other served as a control.
After 3 months and 1 year and 8 months, the lasting effect of the course was evaluated. The results were as follows:
1) After 3 months, the difference between the experimental and control groups was statistically significant at P<0.05.
2) After 1 year and 8 months, there were no significant differences between both groups.
3) No differences existed in both groups between caving products after 3 months and 1 year and 8 months.
