Methods: A postal questionnaire to a total of 592 working-age general dentists, selected by systematic sampling from the membership list of Finnish Dental Association, was sent in April 2004, and a reminder in June. The response rate was 57%. The self-administered questionnaire presented three cases: Composite in an incisor, Composite in a posterior tooth, and Amalgam in a posterior tooth. For each case, the dentists were asked to rank their six most usual reasons for replacement of such restoration, in order of priority, from a list of 12 reasons. In the ranking order, the chosen reasons were scored from 6 to 0, and for analysis, summed up into groups: reasons related to caries (RC), to fractures or failures (RF), and to other, such as esthetics (RO). Dentists' gender and working sector (public/private) served as background information. Differences in the mean scores were evaluated by ANOVA.
Results: For composite restoration in incisor, RF dominated with 56% of the sum scores, the mean score being 11.1, followed by RC (5.3) and RO (3.5), the latter being greater for private-sector dentists (p=0.04). For composite restoration in posterior tooth, RF made 48% of the sum scores, the mean score being 9.5, higher for male than female dentists (p=0.009); mean score of RC was 7.8 and of RO, 2.6, being slightly higher for private than public-sector dentists (p=0.07). For amalgam restoration, RF made 51% of the sum scores, followed by RC (8.5) and RO (1.1), all with no gender-differences. RO earned higher scores by the private-sector dentists (1.6 vs. 0.8; p<0.001).
Conclusion: Fractures and failures dominated as dentists' perceived reasons for replacement of restorations.
Acknowledgements: Helsinki City and Finnish Dental Society Apollonia