Expanded classification for immediate molar implant placement: Integrating root socket strategies beyond septal bone typing

This conceptual development study with exploratory clinical analysis aimed to create and preliminarily evaluate a six-category classification system for immediate implant placement (IIP) in molar extraction sites. IIP in molar regions remains challenging due to complex socket morphology and variable septal bone availability. Existing septal-based classifications (e.g., Smith-Tarnow) may exclude viable cases with favorable root socket anatomy. The system was developed through literature review, CBCT-based anatomical analysis, and Delphi expert consensus, with clinical applicability assessed via retrospective review of 64 M IIP cases. A classification system combining septal bone conditions (Types A-C) and root socket-based anchorage (Types D, M, and P) was developed through literature review, CBCT-based anatomical assessment, retrospective case evaluation, and expert consensus via a Delphi process. Type A demonstrated highest predictability (insertion torque >30 N/cm, survival >90 %). Type B commonly required grafting for gaps >2 mm, while Type C relied on adequate buccolingual cortical engagement. Types D and M provided reliable anchorage in suitable sockets with careful prosthetic planning. Type P showed consistently high primary stability (ISQ >60), minimal early marginal bone loss (<0.2 mm at 6–24 months), and favorable short-term outcomes, supporting its role as a sinus augmentation alternative in selected maxillary molars. The proposed six-category system provides a comprehensive anatomy-based framework for molar IIP, integrating septal and root-specific considerations to expand case selection, shorten treatment time, and maintain predictable outcomes, serving as a decision-making adjunct to comprehensive anatomical and prosthetic assessment.