Objectives: The purpose of the study was to evaluate the intra- and inter-examiner variability of a panel of examiners using a 'glance and grade' marking system when assessing Class II preparations.
Methods: The examination panel consisted of five university staff with varying clinical and teaching experience. The panel assessed 75 disto-occlusal preparations suitable for restoration with dental amalgam prepared in extracted human premolar teeth. The majority of the preparations were cut by undergraduates in their preclinical year of study and the remainder by an experienced staff member. The panel were blind to the identity of each operator.
Results: The study revealed a high degree of both intra- and inter-examiner variability, with some preparations being given a pass on one occasion and a fail on another and vice-versa. In addition, some of the panel, perhaps assuming that the practical exercise had been prepared entirely by undergraduates, were reluctant to award good grades.
Conclusions: The study has highlighted the need for better staff training and a more comprehensive system of assessing preclinical skills.