Endodontic treatment outcomes in a large patient population in the USA: an epidemiological study

Abstract

Outcome assessment of endodontic treatment is critical for appropriate case selection and treatment planning. However, reports on outcomes of nonsurgical endodontic treatment vary considerably. Epidemiological studies done in a large patient population and over a long follow-up period can provide the clinician with useful tools for clinical decision-making and assessment of tooth prognosis. In this study, outcomes of initial endodontic treatment done in 1,462,936 teeth of 1,126,288 patients from 50 states across the USA was assessed over a period of 8 yr. Treatment was done by private general practitioners and endodontists participating in the Delta Dental Insurance plan that insures approximately 14 million individuals in the USA. Overall, 97% of teeth were retained in the oral cavity 8 yr after initial nonsurgical endodontic treatment. The combined incidence of untoward events such as retreatments, apical surgeries, and extractions was 3% and occurred mostly within 3 yr from completion of treatment. Analysis of the extracted teeth revealed that 85% had no full coronal coverage. A significant difference was found between covered and noncovered teeth for all tooth groups tested (p < 0.001). In conclusion, it appears that initial nonsurgical endodontic treatment is a predictable procedure with high incidence of tooth retention after 8 yr.