The objectives of this two-phased study were to examine the relative importance of biological, sociodemographic, economic, attitudinal, and care-seeking factors in explaining the reasons for tooth extraction. The first phase was independent of the second; it is a complete study without the second phase. Phase I of this study described the biological condition of extracted teeth (attachment loss, coronal and root caries, etc.) and the individuals who have had their teeth extracted. Phase II was a study of the factors that influenced the treatment choice between tooth extraction and its alternatives (e.g., root canal, crown, or amalgam filling). One of the features of the design that made this study unique was that data were collected from biological specimens (Phase I only), clinical examinations (both phases), and self-administered questionnaires (both phases). Data collection for both phases of the project was completed by 1995; data processing and editing of the data continued throughout 1996. From the Connecticut and North Carolina study sites, Phase I data were collected from 149 dentists, 1,306 patients, and 1746 extracted teeth. The purpose of Phase 1 is to characterize the biological condition of extracted teeth and to determine the predictors of having a salvageable tooth extracted. Data from Phase II collected from 58 dentists and 740 patients in the two study sites combined will be used to develop and estimate a model that explains the factors that influence the treatment choice between extraction and restoration alternatives. This year the following progress was made. Extracted teeth were found to exhibit a wide range of clinical conditions with a considerable proportion characterized as salvageable (52.9 percent of the teeth extracted in Connecticut were determined a posteriori to have been salvageable, and 61.8 percent were salvageable in North Carolina). These preliminary analyses also showed root caries to have been a more important reason for tooth loss than was hypothesized. Other preliminary analyses identified several predictors of having had a salvageable tooth extracted, such as the age, general self-perceived health, and pattern of use of routine dental services of the patient. These findings may help identify risk factors that could be modified so that tooth extraction for salvageable tooth conditions becomes less common.
