ACCURACY AND PRECISION IN THE RADIOGRAPHIC DIAGNOSIS OF CLINICAL INSTABILITY IN BRANEMARK DENTAL IMPLANTS

The aim was to evaluate accuracy and precision in the radiographic dia gnosis of clinical instability in Branemark dental implants, In two cl inics specialized in the Branemark osseointegration technique we ident ified all patients in whom lack of clinical stability of one or more f ixtures had been observed during a 5-year period. Radiographs of these fixtures (n=62) were mixed with radiographs of clinically stable fixt ures (n=158). Eight observers were asked to determine whether or not a perifixtural radiolucency was seen by means of a 5-point rating scale expressing the confidence with which the presence or absence of a rad iolucency was determined. Receiver operator characteristic analysis wa s used to calculate the A(z) values and the variability in A(z) values between and within observers was determined. In addition, we evaluate d the agreement in rating codes within observers between repeat examin ations. The A, values (mean=0.844 at the first reading and 0.856 at th e second) indicated that the accuracy in radiographic diagnosis of cli nical fixture instability was as least as good as that associated with other radiographic tasks such as approximal caries diagnosis and diag nosis of small periodontal bone lesions. Interobserver variability was larger than intraobserver variability. Intraobserver agreement in rat ing codes was relatively high and less than an average of 6% of all ra tings differed with two rating codes or more, Despite the relatively g ood diagnostic accuracy, the probability of predicting clinical fixtur e instability from a radiographic examination can be low in population s with a low prevalence of fixtures showing clinical instability.