Background/Objectives: Cancer patients undergoing chemotherapy (CT) or radiotherapy (RT) are at increased risk of oral complications. Preventive dental care has been proposed to mitigate these risks, yet its effectiveness is not sufficiently evaluated. This systematic review and meta-analysis aimed to assess the impact of preventive oral health interventions on key clinical outcomes in oncology patients. Methods: A systematic search of MEDLINE, Embase, and CENTRAL databases was conducted (March 2025), adhering to PRISMA guidelines with a PROSPERO-registered protocol (CRD 420251006799). Eligible studies included randomized trials, cohort studies, and pre–post intervention studies evaluating preventive dental care in patients receiving CT or RT. The outcomes included gingival index (GI), dental caries (DMFT), plaque levels, and periodontal health. Meta-analyses were performed on GI and DMFT outcomes using random-effects models. Results: Eleven studies were included in the qualitative synthesis and four in the meta-analyses. Preventive interventions, such as fluoride applications, oral hygiene education, and regular professional cleanings, were associated with stabilization or improvement of gingival health. The pooled estimate for GI showed no significant deterioration over time (MD = −0.05, 95% CI: −0.34 to 0.24, p = 0.72). For DMFT, a slight but significant increase was observed (MD = 1.07, 95% CI: 0.08 to 2.05, p = 0.03), suggesting a continued risk of caries despite intervention. Conclusions: Preventive dental care interventions appear to support the maintenance of gingival health in cancer patients undergoing CT or RT. However, despite these interventions, a slight increase in dental caries was still observed, indicating that preventive strategies may not fully eliminate the risk of caries. These findings highlight the importance of sustained and individualized oral health programs as part of comprehensive oncology care. Future studies using standardized protocols and longer follow-up periods are needed to better evaluate their long-term effectiveness across diverse cancer populations.

Oral diseases affect an estimated 3.5 billion people globally and remain among the most prevalent noncommunicable conditions. Despite recent global policy commitments under the WHO Global Oral Health Strategy and Action Plan (2023–2030), substantial variation persists in how countries structurally embed oral health within national health systems. A structural classification of all 194 WHO Member States was conducted using WHO 2022 oral health country profiles and official policy documentation. Countries were categorized according to financing architecture and entitlement design into four integration models: Structural UHC Integration, Partial or Targeted Integration, Predominantly Private or Insurance-Driven Systems, and Minimal or Emerging Integration. Regional and global distributions were calculated using RStudio (version 2025.09.0, Posit Software, PBC, Boston, MA, USA). Globally, Partial or Targeted Integration represents the most common configuration (44%), followed by Predominantly Private systems (17%) and Minimal or Emerging Integration (15%), while Structural UHC Integration accounts for approximately 10% of countries. Marked regional heterogeneity was observed, with Structural UHC Integration concentrated in selected regions and Minimal or Emerging models more prevalent in parts of Africa and South-East Asia. Findings suggest that integration is primarily determined by financing architecture and legally defined entitlements rather than national income level alone. Structural embedding of oral health within pooled universal coverage mechanisms appears to be an important structural feature associated with higher levels of integration.