Patients may experience tooth loss during supportive periodontal therapy, Study says

The study is published in the Journal of Dentistry.

F.Schwendicke and colleagues from the Department of Oral Diagnostics, Digital Health and Health Services Research, Charité– Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Germany conducted the present study with the objective to to predict patients' tooth loss during supportive periodontal therapy across four German university centers.

The authors assessed a total of 897 patients who had tooth loss in four centers (Kiel (KI) n = 391; Greifswald (GW) n = 282; Heidelberg (HD) n = 175; Frankfurt/Main (F) n = 49) during supportive periodontal therapy (SPT).

Our outcome was annualized tooth loss per patient, explained Schwendicke. Multivariable linear regression models were built on data of 75 % of patients from one center and used for predictions on the remaining 25 % of this center and 100 % of data from the other three centers.

The prediction error was assessed as root-mean-squared-error (RMSE), i.e., the deviation of predicted from actually lost teeth per patient and year.

The results revealed that-

1. Annualized tooth loss/patient differed significantly between centers (between median 0.00 (interquartile interval: 0.00, 0.17) in GW and 0.09 (0.00, 0.19) in F, p = 0.001).
2. Age, smoking status and number of teeth before SPT were significantly associated with tooth loss (p < 0.03).
3. Prediction within centers showed RMSE of 0.14−0.30, and cross-center RMSE was 0.15−0.31.
4. Predictions were more accurate in F and KI than in HD and GW, while the center on which the model was trained had a less consistent impact.
5. No model showed useful predictive values.

Hence, the authors concluded that "while covariates were significantly associated with tooth loss in linear regression models, a clinically useful prediction was not possible with any of the models and generalizability was not given. Predictions were more accurate for certain centers."

Furthermore, they mentioned that the association should not be confused with predictive value: Despite significant associations of covariates with tooth loss, none of our models was useful for prediction. Usually, model accuracy was even lower when tested across centers, indicating low generalizability.