Mahidol Study 2: Treatment Outcomes and Prognostic Factors of Regenerative Endodontic Procedures in Immature Permanent Teeth

INTRODUCTION: Studies on the clinical outcomes and prognostic factors of regenerative endodontic procedures (REPs) in a large population and long-term recall period have been limited. Therefore, the aims of this study were to evaluate treatment outcomes and prognostic factors of REPs. METHODS: Immature permanent teeth treated with REPs with a minimum one-year follow-up period were included. Treatment outcomes (functional retention, healed rate, root development, and sensibility test response) and any prognostic factors were analyzed with multivariable Cox regression, linear regression, and modified Poisson regression. RESULTS: One-hundred-twenty REPs teeth with a mean 41.7-month recall period were included with a functional retention rate of 97.5%. The healed, healing, and diseased rates of REPs were 80%, 9.2%, and 10.8%, respectively. Significant prognostic factors for healed were age (<12 years old) and root development stage (stages 4 and 5). Changes in the apical diameter, root length, root width, and radiographic root area after REPs were 56.8%, 8.3%, 23.2%, and 21.7%, respectively. Significant prognostic factors for continued root developmevnt were age and etiology of pulpal disease (from caries or dental anomalies). The sensibility test response rate was 41.7% with significant positive factors of ethylenediaminetetraacetic acid irrigation and capping material level above the cemento-enamel junction. CONCLUSION: REPs demonstrated high functional retention and healed rates. Patients <12 years old presented a higher healed rate and continued root development (excluding root length). Dental caries or anomalies had higher continued root development compared with dental trauma. The sensibility test response was related to ethylenediaminetetraacetic acid irrigation and level capping material.