Development of a classification and index of dental treatment experience for adults

OBJECTIVE: To develop and evaluate a classification and index of dental treatment experience for adults. DESIGN: Twenty-four general dental practitioners recorded treatment experience at baseline on 4,211 regularly attending adults of whom 3,878 were re-examined after one year and 3,698 patients completed a questionnaire on factors related to treatment. SETTING: Health authorities of Manchester and Salford. METHOD: Set theory was used to divide the baseline clinical data set into 7 mutually exclusive classes of dental treatment experience. Seven dental specialists used the nominal group technique to weight tooth status to form an index of dental treatment experience (DTE). The ability of the DTE classification and index to discriminate between groups of patients' responses to the questionnaire was compared with the THI and DMFT index. RESULTS: Ninety-nine per cent of the patients fell into 5 hierarchical classes ranging from fillings only to wearing a denture in addition to a crown and/or bridge. When calculated on the baseline data, the classification discriminated between 16 of the 20 variables investigated in the questionnaire. Fifteen significant differences were found between mean scores for groups of patients on the DTE index, 14 on the THI and 8 on the DMFT index. Fifty-five (1%) patients moved their class as a consequence of the treatment carried out during the year. All three indices found significant differences for the same four variables of the 20 tested. CONCLUSION: A classification of dental treatment experience together with an index to measure the severity of that experience has been successfully developed and tested. It appears to have advantages over the traditional DMFT index and is at least as discriminating as the THI.