Outcome and erosion of root-end filling materials following endodontic apical surgery: a minimum follow-up of 4 years.

OBJECTIVES: To evaluate the long-term outcomes of apical surgery using intermediate restorative material (IRM) and hydraulic calcium silicate cements (HCSCs) as root-end filling materials. MATERIALS AND METHODS: Apical surgery was performed between 2012 and 2020. Of the 336 teeth initially treated, 137 met the final inclusion criteria. Periapical healing was classified as complete, incomplete, uncertain, or unsatisfactory. Root-end filling material erosion was assessed radiographically using the Erosion Index (EI), ranging from 0 to 4. RESULTS: The mean follow-up period was 6.6 ± 2.7 years. IRM was used in 72 (52.6%), while HCSCs were used in 65 (47.4%) teeth. Complete healing was observed in 84 (61.3%) teeth, incomplete healing in 13(9.5%), uncertain healing in 21(15.3%), and unsatisfactory healing in 19 (13.9%). Fifteen teeth were extracted, resulting in a tooth survival rate of 89.1%. Late failures occurred in 10 (7.3%) of the initially successful cases, with equal distribution between IRM (n = 5) and HCSC (n = 5). Erosion was detected in 20(14.6%) teeth, affecting 11.1% of IRM and 18.5% of HCSC cases, with no significant difference between materials. Complete healing was significantly associated with tooth survival and the absence of late failure (p < 0.001). Teeth exhibiting erosion (EI 1-4) were less likely to achieve complete healing compared with those without erosion (EI 0)(OR = 2.7, 95% CI: 0.8-8.1; p < 0.05). CONCLUSIONS: Apical surgery demonstrated high long-term tooth survival and favourable healing outcomes, irrespective of whether IRM or HCSCs were used. Material erosion was associated with a reduced likelihood of complete periapical healing. These findings emphasize the importance of long-term follow-up, as late failures may occur despite initially successful treatment outcomes. CLINICAL RELEVANCE: These findings suggest that clinical erosion of root-end filling materials has not been extensively investigated previously. It may represent a contributing factor to failures following apical surgery and therefore warrants further research and validation.