Intra- and interexaminer reproducibility of clinical caries diagnoses
was studied using 3 experienced dentists, who independently examined 2
0 patients twice at an interval of 2-6 weeks. The lesions were classif
ied as one of the following four diagnoses: (1) initial active caries,
(2) initial inactive caries, (3) manifest active caries, and (4) mani
fest inactive caries. For the various diagnoses, signs of cavitation,
surface structure and discolouration were used. The reproducibility at
a patient level was evaluated using intraclass correlation coefficien
ts and at a surface level using kappa statistics. At a patient level,
for the total number of lesions, the intraclass coefficients of correl
ation varied from 0.55 to 0.77. For the individual diagnoses, total ma
nifest caries showed the highest coefficients of correlation, ranging
from 0.73 to 0.92. At a tooth surface level, the kappa values varied f
rom 0.29 to 0.61. The most common shift was that from any type of cari
es diagnosis to a diagnosis of a sound surface. There was little diffe
rence between the results for coronal and root caries and between init
ial and manifest lesions. Nor was there any difference for buccal + li
ngual surfaces only compared to all surfaces. Judging from the pattern
of change in diagnosis between the repeated examinations, the main so
urce of error seemed to be due to the fact that the lesions observed a
t one examination were overlooked at the other examination.