Recognition of veneer restorations by dentists and beautician students

Three types of veneer restorations (VRs) were evaluated for recognition by two groups of observers to study the aesthetic result. The different types of VRs were: porcelain, direct resin composite and indirect resin composite. One month after insertion of the VRs, colour transparencies were made of smiling patients randomly selected from a group of 112 patients participating in a clinical trial. The slides were evaluated by five dentists who were not familiar with the patients and by 25 beautician students (BS). Dentists were asked to locate the VRs which were present in the patients and to specify the type of VR. BS were only asked to locate the VRs. To trace a possible relationship between the aesthetic result of the treatment and a number of variables, ANOVA was applied to evaluate the variables: 'discolouration of the teeth' before treatment, 'type of VR' and 'number of VRs'. Agreements in judgement were expressed in Cohen-Kappa coefficients. The results showed that the dentists could locate the VRs quite well (Kappa coefficient 0.64 +/- 0.28) but for BS this was lower (Kappa coefficient 0.43 +/- 0.27). The more VRs were made in one patient, the more difficult it was to locate them correctly. The other variables had no significant effect on the recognition of the VRs. It was not possible for the dentist observers to differentiate between the types of VRs.