Oxidative stress burden in endodontic infection: Gingival crevicular fluid 8-isoprostane in hypertensive patients with symptomatic apical periodontitis cross sectional observational study

Introduction Hypertension and endodontic infection may share oxidative stress–mediated mechanisms. This cross-sectional observational study compared gingival crevicular fluid (GCF) 8-isoprostane levels across healthy controls, hypertensive patients, systemically healthy patients with pulp necrosis and symptomatic apical periodontitis (SAP), and hypertensive patients with pulp necrosis and SAP. Methods Two hundred participants were classified into 4 groups (n = 50/group). GCF samples were collected and 8-isoprostane was quantified using enzyme-linked immunosorbent assay. Categorical variables were analyzed using the chi-square test. Between-group differences in 8-isoprostane were assessed using one-way ANOVA (Welch ANOVA when indicated) and analysis of covariance (ANCOVA) adjusting for age and sex; pairwise comparisons used Dunnett T3. Results GCF 8-isoprostane differed significantly among groups. Mean ± SD concentrations were 112.58 ± 10.85 pg/mL in controls, 237.42 ± 37.93 pg/mL in hypertensive patients, 201.36 ± 13.81 pg/mL in pulp necrosis with SAP, and 239.41 ± 21.52 pg/mL in hypertensive patients with pulp necrosis and SAP. Each disease group exhibited higher 8-isoprostane than controls (all P < 0.001). After adjustment for age and sex, the overall group effect remained significant (ANCOVA P < 0.001). Adjusted estimated marginal means showed no difference between hypertension alone and hypertension plus SAP (P = 1.000). Conclusions GCF 8-isoprostane is elevated in hypertension and SAP relative to healthy status, independent of age and sex. Among hypertensive individuals, concomitant SAP was not associated with additional elevation, supporting GCF 8-isoprostane as a biomarker candidate reflecting oxidative stress burden in these conditions.