Faculty and Self-assessment of Preliminary Impressions Made by Undergraduate Students

Objectives: One of the objectives of competency-based undergraduate curriculum is to equip the students with sufficient skills to enable them to safely deliver dental care to their patients. Impressions are cornerstones for any prosthodontic treatment, the accuracy of which influences the quality, hence longevity of the final prostheses. This study was hence dedicated to faculty and self-assessment of preliminary impressions for completely edentulous arches made by undergraduate students.
Methods: A total of 237 “first-attempt” alginate preliminary impressions (115 maxillary and 122 mandibular) made by 4^th year undergraduate dental students were assessed by 2 calibrated professional faculty assessors and self-assessed by the students themselves. Assessment was based on specific clearly defined criteria and a 3-level rating rubric for each criterion; 0(clinically non-acceptable), 1(acceptable) and 2(ideal). Faculty assessed the impressions independently then together to agree on its acceptability. Impressions were counted acceptable when at-least 1 was scored for all criteria and students were considered competent in this clinical skill. Comparison between assessors’ scores and between faculty and self-assessment scores were statistically analyzed (P< 0.05).
Results: Based on faculty assessment, out of the 237 impressions; 2.5% (4 maxillary and 2 mandibular) were ideal, 62.45% (80 maxillary and 68 mandibular) showed some defects but were still rated acceptable and 35% (31 maxillary and 52 mandibular) were rated unacceptable. Tray selection and border thickness were the most identified defective criteria. Inter-examiner agreement exceeded 95% in most criteria. There were statistically significant differences between faculty and student self-assessment scores with the latter giving higher scores.
Conclusions: Students, in their first clinical course, usually require more than one attempt to make acceptable alginate impressions. Competency was higher with maxillary than mandibular impressions. Clearly-defined criteria and rubric-based assessment resulted in satisfactory agreement levels between assessors verifying assessment consistency. Students tend to over rate their work.