Homeostatic medicine, new thinking on etiological treatment of large cyst-like periapical lesions: Case series and literature review

Objectives: The view that auxiliary surgical resection is needed for the large cystic periapical lesions (LCPLs) treatment is based more on theoretical hypotheses than clinical evidence. This study questions the necessity of surgical treatment of LCPLs via providing strong clinical evidence and new theoretical supports from the perspective of homeostatic medicine (HM). Methods: Nonsurgical treatment was performed in two LCPL cases (lesion diameter > 20 mm), and long-term follow-up was obtained (> 8 years, up to 18 years in one case). The PubMed, Web of Science, CINAHL, Embase and Cochrane CENTRAL databases were electronically searched (01-01-2003 to 07-31-2023). Studies on LCPLs with at least six months of postoperative review according to clinical and radiological criteria were summarized. Meta-analysis of the non-surgical treatment success rate was performed with RStudio software. Results: Two LCPL cases showed complete periapical lesion resolution after non-surgical treatment. Fourteen studies fulfilled the inclusion criteria, with no obvious publication bias. The worldwide nonsurgical treatment success rate of LCPLs was estimated as 89% (95% CI=85%-94%) in 288 teeth. Conclusions: The pathological hypothesis of true and bay cysts is meaningless for clinical decision-making of LCPLs. Nonsurgical root canal treatment removes the bacterial infection and can achieve successful outcomes even if large bone defects exist.