Oral Manifestations in a Drug-Addicted Population Being Treated in Rehabilitation Clinics in Northern Portugal: A Cross-Sectional Observational Study

Abstract Drug addiction is a growing global health concern with significant oral health consequences. Cannabis and cocaine are among the most frequently used illicit drugs, contributing to a high burden of oral pathologies. This study aimed to analyze the most prevalent oral manifestations and associated risk factors among users of legal and illicit substances in drug rehabilitation clinics in Northern Portugal. A cross-sectional observational study was conducted with 100 individuals aged 18 to 70 years (mean age: 41.50 ± 12.55) undergoing addiction treatment. Participants completed a structured questionnaire and underwent an intraoral clinical examination. Descriptive statistics and chi-square tests/Fisher's exact tests were used to assess associations between qualitative variables. The level of statistical significance used was 0.05. High prevalence of alcohol (100%), tobacco (82%), and illicit drug use (88.6%) was observed. Although 53.8% reported daily toothbrushing, inadequate oral hygiene was evident. The most frequent oral conditions were periodontitis (64%), tooth sensitivity (49%), dental caries (47%), and bruxism/temporomandibular disorders (30%). Periodontitis and gingival bleeding were significantly associated with the duration of illicit drug use (p < 0.05). Gingival bleeding and oral mucosal inflammation were significantly associated with toothbrushing frequency (p < 0.05). Additionally, periodontitis was significantly associated with the use of hygiene aids (p < 0.05). Overall, this study provides valuable information about the oral health challenges faced by drug addicts in rehabilitation clinics in Northern Portugal and highlights the importance of addressing oral health as part of comprehensive addiction treatment programs.