ASSESSMENT OF INTEREXAMINER VARIABILITY AND CRITERIA FOR POST AND CORE PREPARATION BY ANALYTIC RUBRICS
The aim of this study was to assess the various criteria involved in the post and core preparations by the dental students, using an analytic rubric. Seventy-one dental students and six faculty members participated in the study. The students prepared an ivorine single rooted premolar for a cast post and core. The preparation included post-length, post-diameter, ferrule, pattern fabrication and adaptation of the post. The evaluators for the grading used a custom designed 10-point rubric. Variation in all the preparation parameters existed. Overall mean grade was 6.83+1.50 out of ten, with highest and lowest grades awarded were by the evaluator-6 (7.38+.95) and evaluator-4 (5.97+1.51), respectively. This indicated a moderate over all scoring/performance of the students. Students scored highest and lowest in the criteria of post-length (1.45+.47) and post-adaptation (1.30+.54), respectively. The maximum variation of 1.41 in grades was found between evaluator-4 (Total Grade=5.97) and evaluator-6 (Total Grade=7.38). The lowest difference of .02 in total grades was found between evaluator-2 (Total Grade=7.36) and evaluator-6 (Total Grade=7.38). The use of rubrics for the assessments of various success criteria of post and core preparations by the dental students is useful, and can help in finding the inaccuracies and deficiencies within each criterion of their work. Variations in the evaluator’s grades still existed despite utilizing analytical rubrics, underscoring the need for continuous efforts in improvement of the rubrics.