Comparative analysis of prognostic outcomes between isolated endodontic lesions and endodontic-periodontal combined lesions following microsurgical intervention

INTRODUCTION. Endodontic microsurgery (EMS) has become an effective modality regarding the treatment of enduring periapical pathology after non-surgical failure of retreatment of the root canal. Nevertheless, the predictability of EMS in periodontal destruction that accompanies teeth is still an area of controversy. The aim of the study was to determine the difference in clinical and radiographic healing of isolated endodontic lesions (IEL) and endodontic-periodontal combined lesions (EPCL) after using microsurgical intervention. MATERIALS AND METHODS. A cohort retrospective study was carried out on 148 teeth among 148 patients who attended EMS between the year 2022 and 2024. Cases were classified into two according to the preoperative probing depths in radiograph and clinical probing depths: Group A (IEL, n = 76) which included lesions of a strictly endodontic nature, and Group B (EPCL, n = 72) which included lesions of a true combined nature with periodontal communication. Each of the procedures involved the use of an operating microscope, ultrasonic retropreparation, and bioceramic retrograde filling. Group B also was targeted with guided tissue regeneration (GTR). Molven criteria were used to determine clinical and radiographic healing at a 12-month follow-up. RESULTS. The general success rate was 87.2. The success rate of Group A (IEL) was much higher, 94.7% (72/76), than the success rate of Group B (EPCL) was, 79.2% (57/72) ( p = 0.006). The average decrease in lesion size was 84.3 ± 12.1 in Group A and 66.8 ± 18.4 in Group B ( p < 0.001). Although the marginal stability of the bone was attained at 88 per cent in EPCL cases, full regeneration of the periodontial apparatus was not predictable as compared with apical bone healing. CONCLUSIONS. Although endodontic-periodontal mixed lesions have lower success rate of treatment than endodontic lesion alone, combination of microsurgery with regenerative therapies is still a tooth-saving procedure. But the level of periodontal loss is a decisive prognostic factor.