Gulabivala Kishor, Ng Yuan Ling
Unit of Endodontology, Department of Restorative Dentistry, UCL Eastman Dental Institute, University College London, London, UK.
Int Endod J. 2023 Mar;56 Suppl 2:82-115. doi: 10.1111/iej.13897. Epub 2023 Feb 10.
This paper undertakes a broad and comprehensive synthesis of relevant clinical, biological, biomechanical, technical and healthcare services data to understand the factors affecting outcomes of periapical healing after root canal (re)treatment. The medical and dental evidence-based era (1980-present) is contextualized with the earlier evidence drive in endodontics (1911-1940) triggered by the focal infection era. The current evidence-based approach has a sharper focus on evidence quality and derivation of practice guidelines. Contrary views question whether guideline-driven, or expertise-development-driven endeavours would best serve outcome improvement in society. The endodontic discipline functions in a broad healthcare framework and sustains industrial, economic and trend pressures that may be deemed to influence outcomes. The nature of root canal treatment and the challenges in determining the factors that affect its outcomes is discussed. The factors potentially affecting periapical healing after root canal treatment are classified into pre-operative, intra-operative and postoperative groups. These categories subsume multiple elements with interactive influences, creating a complex picture, further confounded by some apparently surprising, counter-intuitive and contradictory findings. The technical versus biological conundrum in root canal treatment continues to cause cognitive dissonance. However, due reflection and cross-discipline-synthesis resolve the apparent data conflicts into a very simple, consistent and plausible picture of how root canal treatment works and the key factors that affect periapical healing. Root canal retreatment is considered mainly in the context of its differences from primary treatment as the majority of factors influencing outcomes are common to both. The exceptional difference is that retreatments have a proportionately reduced probability of healing by virtue of compromised apical root canal ramification access or modified host/infection interactions. Root canal (re)treatment outcomes are dominantly influenced by the nature of prior dynamic host/infection interaction (pre-operative patient factors) and how the direction of this dynamic is influenced by two factors: (1) the active efficacy of the operators' root canal treatment protocol to sustain a microbial ecological shift (intra-operative treatment factors) and dampen periapical inflammation; and (2) the passive ability of the functional tooth (and its restoration margin) to maintain its integrity to resist infection reversal (postoperative restorative factors).
本文对相关的临床、生物学、生物力学、技术和医疗服务数据进行了广泛而全面的综合分析，以了解影响根管（再）治疗后根尖周愈合结果的因素。医学和牙科循证时代（1980年至今）与由病灶感染时代引发的牙髓病学早期循证驱动（1911 - 1940年）相关联。当前的循证方法更加注重证据质量和实践指南的推导。相反的观点质疑以指南为导向或专业发展为导向的努力是否最有利于社会结局的改善。牙髓病学科在广泛的医疗框架中发挥作用，并承受着可能被认为会影响结局的产业、经济和趋势压力。本文讨论了根管治疗的性质以及确定影响其结局的因素所面临的挑战。根管治疗后可能影响根尖周愈合的因素分为术前、术中和术后三组。这些类别包含多个具有相互作用影响的要素，形成了一幅复杂的图景，一些明显令人惊讶、违反直觉和相互矛盾的发现进一步加剧了这种复杂性。根管治疗中的技术与生物学难题继续导致认知失调。然而，经过适当思考和跨学科综合，将明显的数据冲突化解为一幅非常简单、一致且合理的关于根管治疗如何起作用以及影响根尖周愈合的关键因素的图景。根管再治疗主要在其与初次治疗的差异背景下进行考虑，因为影响结局的大多数因素两者共有。特殊的差异在于，由于根尖根管分支通路受损或宿主/感染相互作用改变，再治疗的愈合概率相应降低。根管（再）治疗结局主要受先前动态宿主/感染相互作用的性质（术前患者因素）以及这种动态方向如何受到两个因素影响：（1）操作者根管治疗方案维持微生物生态转变的积极效果（术中治疗因素）并减轻根尖周炎症；（2）功能牙（及其修复边缘）保持其完整性以抵抗感染逆转的被动能力（术后修复因素）。
