The Accuracy of Dental Students and Dentists Assessing the Total Occlusal Convergence of Crown Preparations

This study examined the ability of dental students and qualified dentists to visually assess the total occlusal convergence of clinical crowns. 10 working casts of maxillary molar crown preparations were installed in phantom heads in a clinical skills laboratory. 87 participants assessed the buccolingual and mesiodistal total occlusal convergence of the casts. 2nd-year students with no experience in fixed prosthodontics served as a control group with 3rd, 4th and 5th-year students and qualified dentists including specialists in restorative dentistry involved. Differences were calculated between the measured angles and the subject's estimate to assess accuracy. For 8 of the 20 surfaces measured there were significant differences. (p ⟨ 0.05). Differences were not standardized between the groups, with no clear patterns of difference in tooth type or aspect assessed. Differences were primarily between the control group and the more experienced groups. The remaining groups were of similar ability. A minority of participants in each group were highly divergent from their peers. This study found significant differences between participants with no experience of fixed prosthodontics and those with experience, however, the ability to assess total occlusal convergence does not appear to improve significantly with experience.