Restorative treatment thresholds and agreement in treatment decision-making.

It has been recognised for many years that treatment decision-making among dentists often shows wide variation. This study sought to examine the effect of dentists' stated treatment thresholds as a source of variation between them. Twenty dentists made 360 treatment decisions about the approximal surface of extracted teeth seen in simulated bitewing radiographs. They also stated their personal treatment thresholds, i.e. the depth of lesion which they intended to restore. One hundred and ninety pairwise comparisons of treatment decisions showed that only 16% of the dentist pairs showed substantial agreement. Dentist pairs who reported that they held the same interventive threshold achieved exactly the same mean level of agreement in treatment decision-making as dentist pairs who disagreed about the appropriate threshold for restorative intervention. The study suggests that restorative thresholds which are reported to be used by dentists may be poorly correlated with the number of positive treatment decisions actually made.