Since 1988, the AIDS Linked to the Intravenous Experience (ALIVE) study has successfully followed a lower-income, predominantly African American population of HIV-infected and at-risk persons with a history of injecting drugs (PWID) in a community-based cohort in Baltimore. Over three decades, ALIVE has characterized risk factors of incident HIV and progression to AIDS or death, described patterns of risk behaviors, identified barriers to optimal HIV care, and provided important insights into the natural and treated course of HIV among PWID. In recent years, ALIVE has transitioned to exploring the impact of aging with HIV, focusing on phenotypes and organ-specific non-communicable diseases (NCD) (e.g., liver, lung, cardiovascular, bone, kidney, neurocognitive and metabolic NCDs). The proposed project leverages the ALIVE platform to focus on the combined effects of HIV and NCDs on oral health at the health care-seeking, clinical, and microbiological levels. The specific aims of the proposed project are to: 1) determine to what extent HIV status influences access to and utilization of oral health care services; 2) determine to what extent HIV status affects self-reported and clinical oral health status; 3) determine to what extent HIV status influences the progression of periodontitis; and 4) determine to what extent HIV status impacts the periodontitis-associated oral microbiome signature. The key impact of these aims is to illuminate social and individual-level mechanisms, identify modifiable risk factors, and produce novel insights to inform efficient and targeted oral health interventions for PLWH in Baltimore and nationally.