Three types of veneer restorations (VRs) were evaluated for recognitio
n by two groups of observers to study the aesthetic result. The differ
ent types of VRs were: porcelain, direct resin composite and indirect
resin composite. One month after insertion of the VRs, colour transpar
encies were made of smiling patients randomly selected from a group of
112 patients participating in a clinical trial. The slides were evalu
ated by five dentists who were not familiar with the patients and by 2
5 beautician students (BS). Dentists were asked to locate the VRs whic
h 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, ANOV
A was applied to evaluate the variables: 'discolouration of the teeth'
before treatment, 'type of VR' and 'number of VRs'. Agreements in jud
gement 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 effec
t on the recognition of the VRs. It was not possible for the dentist o
bservers to differentiate between the types of VRs.