I. Tomás

Aim To determine the accuracy of biomarker combinations in gingival crevicular fluid (GCF) and saliva through meta‐analysis to diagnose periodontitis in systemically healthy subjects. Methods Studies on combining two or more biomarkers providing a binary classification table, sensitivity/specificity values or group sizes in subjects diagnosed with periodontitis were included. The search was performed in August 2022 through PUBMED, EMBASE, Cochrane, LILACS, SCOPUS and Web of Science. The methodological quality of the articles selected was evaluated using the QUADAS‐2 checklist. Hierarchical summary receiver operating characteristic modelling was employed to perform the meta‐analyses (CRD42020175021). Results Twenty‐one combinations in GCF and 47 in saliva were evaluated. Meta‐analyses were possible for six salivary combinations (median sensitivity/specificity values): IL‐6 with MMP‐8 (86.2%/80.5%); IL‐1β with IL‐6 (83.0%/83.7%); IL‐1β with MMP‐8 (82.7%/80.8%); MIP‐1α with MMP‐8 (71.0%/75.6%); IL‐1β, IL‐6 and MMP‐8 (81.8%/84.3%); and IL‐1β, IL‐6, MIP‐1α and MMP‐8 (76.6%/79.7%). Conclusions Two‐biomarker combinations in oral fluids show high diagnostic accuracy for periodontitis, which is not substantially improved by incorporating more biomarkers. In saliva, the dual combinations of IL‐1β, IL‐6 and MMP‐8 have an excellent ability to detect periodontitis and a good capacity to detect non‐periodontitis. Because of the limited number of biomarker combinations evaluated, further research is required to corroborate these observations.