TNF and chronic kidney disease: CKD promotes a chronic inflammatory milieu, oxidative stress, and uremic toxicity, which collectively impair host defense and periodontal and periapical repair mechanisms, and, conversely, AP and PD act as persistent sources of systemic inflammation, potentially aggravating renal dysfunction through elevated circulating levels of pro-inflammatory cytokines such as IL-6, TNF-α, and CRP [47,50].