The Relationship Between Severity of Apical Periodontitis and Next-Generation Systemic Inflammatory Biomarkers.

Apical periodontitis (AP) is an endodontic infection that may persist asymptomatically and be reflected in systemic inflammatory status. This study aimed to evaluate the association between radiographic severity of AP and next-generation systemic inflammatory biomarkers in systemically healthy adults. Archived clinical, radiographic and haematological data of 206 adult patients treated under general anaesthesia between 2021 and 2024 were retrospectively analysed. Patients were grouped according to Periapical Index (PAI) scores. Systemic immune-inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and platelet inflammatory value (PIV) were calculated from routine blood counts. Severe AP (PAI scores 4-5) was associated with significantly higher SII, NLR, and PIV values (p < 0.05). The number of teeth with PAI score 5 correlated positively with SII, NLR and PIV, whereas PLR showed no significant association. Greater severity of AP was associated with elevated systemic inflammatory indices. PIV may provide adjunctive information on systemic inflammatory response in patients with severe AP.