Practice-based preclinical instruction for gingival displacement with animal models.

ABSTRACT

STATEMENT OF PROBLEM: Gingival displacement is recognized as a substantive and difficult procedure in fixed prosthodontics. However, a realistic simulation of gingival displacement is unavailable for preclinical dental students. PURPOSE: The purpose of this study was to evaluate whether practice-based preclinical instruction of gingival displacement with animal models could improve students' skill in patient care. MATERIAL AND METHODS: Isolated bovine mandibles (calves were younger than 6 months of age) and isolated porcine hemimandibles were prepared for this study. Twenty-two general dental practitioners with at least 5 years of experience were randomly selected and assigned to perform gingival displacement on both bovine and porcine jaws. Those practitioners were then asked to assess the clinical similarity of gingival displacement between human teeth and animal teeth. The data were analyzed with the paired t test (α=.05). Upon confirmation that the animal jaw provided a similar gingival displacement environment to that of human teeth, 80 predoctoral dental students were enrolled and randomized into 2 groups. Half of them underwent the new practice-based instruction, while the others underwent traditional preclinical teaching only (lectures, online video, or live demonstration). After preclinical learning, clinical performance in gingival displacement was evaluated for all students in terms of the effect of gingival displacement and quality of impression. The data were analyzed with the chi-square test (α=.05). RESULTS: The dentogingival environments of porcine and bovine jaws were similar to those of human jaws, and no significant difference was detected between these 2 animal models (P=.178). A significant increase occurred in the acceptable rate of the effect of gingival displacement (P<.001) and the quality of impression (P<.001) among students who received the practice-based instruction compared with those who received traditional teaching. CONCLUSIONS: These findings suggest that this practice-based instruction of gingival displacement with animal models is an effective method of promoting dental students' learning of gingival displacement.