Minimally Invasive Endodontic Access Cavities: A Systematic Review of Dentin Preservation Strategies and Clinical Outcomes

Introduction: The paradigm of endodontic access cavity preparation has evolved significantly from traditional principles, which prioritized straight-line access at the expense of pericervical dentin (PCD). This critical zone is paramount for the biomechanical integrity of the tooth. This systematic review aims to synthesize the current literature on minimally invasive endodontic access (MIE) designs, evaluating their efficacy in preserving tooth structure and their impact on treatment outcomes. Methods: A narrative synthesis of the literature was conducted, reviewing key texts and contemporary research on endodontic access preparation. The focus was on studies and clinical reviews concerning PCD preservation, fracture resistance, and the application of modern armamentarium. Results: The review identifies the limitations of traditional access cavities, including excessive removal of PCD and the soffit, leading to an increased risk of fracture. Modern approaches, facilitated by dental microscopes, ultrasonic instruments, and specialized burs (e.g., EndoGuide, CK Burs), enable more conservative preparations. Techniques such as truss access, ninja access, caries-driven access, and digitally guided access are detailed, highlighting their role in strategic dentin conservation. The concepts of 3D ferrule and banking tooth structure via the soffit are emphasized as crucial for long-term success. Conclusion: Minimally invasive endodontics represents a clinically viable shift towards preserving tooth structure. By prioritizing the conservation of PCD and leveraging technological advancements, clinicians can enhance the fracture resistance and long-term prognosis of endodontically treated teeth. Further in-vivo studies are recommended to standardize protocols and solidify the evidence base for these techniques.