Endodontic Microsurgery in Private Practice: Indications and Time-Period Trends Before and After Adoption of Laser-Activated Irrigation - A Retrospective Cohort Study

Objectives To characterize indications for endodontic microsurgery (EMS) in a large private practice cohort and compare indication distributions before and after adoption of laser-activated irrigation (LAI) in non-surgical treatment. Materials and Methods A retrospective cohort of consecutive EMS cases ( n  = 1,672) treated by six endodontists (April 2019–August 2025) was analyzed. Two periods were prespecified: Before-Laser Treatment (BLT) and After-Laser Treatment (ALT) following implementation of an Er,Cr:YSGG intracanal LAI protocol (August 2022). Each surgical tooth was assigned one or two predefined reasons. Proportions were compared between periods with Pearson’s χ² test and 95% Wald confidence intervals. Results The most frequent indications overall were uncleaned accessory canal (22.7%), large post (22.3%) and excessive calcification (14.4%). Surgeries for uncleaned accessory canals decreased from 28.6% (219/767) in BLT to 17.7% (160/905) in ALT (difference − 10.9 percentage points; 95% CI − 14.9 to − 6.8; P < .001). Surgeries for excessive calcification increased from 10.8% (83/767) to 17.3% (157/905) (difference + 6.5 percentage points; 95% CI + 3.2 to + 9.8; P < .001). Conclusions In this practice-based cohort, LAI adoption was associated with fewer EMS for uncleaned accessory canals. By contrast, calcification-related EMS increased, a pattern compatible with delayed pulp-canal obliteration rather than a direct LAI effect. Causal inference is limited by the time-period design. Clinical Relevance The adoption of laser-activated irrigation (LAI) in non-surgical endodontics may reduce the necessity for subsequent microsurgery related to uncleaned accessory anatomy. Conversely, clinicians should anticipate a continued or increasing burden of calcification-related cases, potentially influenced by broader factors like pandemic-associated stress.