Prescribing endodontic retreatment: towards a theory of dentist behaviour.

The large variations observed in dentists' management of periapical lesions in endodontically treated teeth suggest that disease concepts used in clinical practice should be investigated. In the present study it was hypothesized that dentists regard various periapical conditions as different stages on a health continuum. Variations could then be regarded as the result of the individuals selection of differing cut-off points for prescribing retreatment. The hypothesized decision-making model was tested using dental students in Amsterdam (Holland), Gothenburg (Sweden) and Pavia (Italy). The students were shown six simulated cases among which the quality of root filling seal and presence of post and crown were systematically varied. For each case, management of five periapical conditions was assessed. Five options were offered: no therapy, wait-and-see, nonsurgical retreatment, surgical retreatment, and extraction. For each examiner and case a 'retreatment preference score (RPS)' was established. The investigation showed large interindividual variations in RPS. A statistically significant higher mean RPS was seen among students in Pavia compared with students in Amsterdam and Gothenburg. Among all observers and cases it was found that if retreatment was proposed for a certain size of lesion, retreatment was subsequently selected for all larger lesions. The experiment gave evidence in support of the proposed hypothesis. The data also suggest that the choice of retreatment criterion is affected by values, costs of retreatment and technical quality of the original treatment.