An experimental evaluation of the effectiveness and efficiency of the leadup activity.

The positive effects of a leadup activity on the production of intracoronal operative preparations have been documented in earlier studies. However, an absence of certain controls may have jeopardized the validity of the earlier study, and an adequate test of the innovation's efficiency was not undertaken. The purpose of this investigation was to evaluate the effects of a leadup activity implemented as part of the scheduled laboratory course, when the amount of supervision provided to the experimental subjects during the entire course was reduced significantly, and when subjects were assigned randomly to the two conditions. Calibrated raters, blind to group affiliation of products, graded all preparations. Mean scores for the experimental group (n = 35) were superior to those of the control group (n = 29) for all five preparations, and were statistically significantly (p less than .05) higher on three. Self-evaluations were equivalent to rater evaluations for subjects in the experimental group but not for those in the control group. Self-reports suggest that students receiving leadup training used fewer teeth to practice each of the preparation styles. Anecdotal data indicate that instructors in the experimental group may have found their job no more difficult than it had been in the past. It is concluded that the leadup activity improves performance and increases efficiency as measured by the faculty-student ratio and amount of practice required by students.