Is there an association between drug use and oral health conditions?

Data sources Databases searched included PsycINFO, PubMed, SciELO, Scopus and Web of Science.Study selection Cross-sectional, longitudinal and retrospective studies that compared caries, periodontal disease or tooth loss in people who use drugs as compared to those who do not. Studies that included psychiatric populations and alcohol or tobacco users were not included in the review. Qualitative studies, in vitro investigations, animal studies, reviews, case reports and series, letters to editor and conference abstracts were also excluded. The authors included only English studies published before 1 July 2019. Two independent reviewers screened the papers on title and abstract and then full text. In case of disagreements, these were discussed between the two reviewers and a third one was consulted if needed.Data extraction and synthesis Two reviewers extracted the data and contacted the primary authors for necessary clarifications, if needed. The unweighted kappa was applied to examine inter-examiner agreement. The Joanna Briggs Institute Critical Appraisal Checklist for observational studies was used to critically appraise the studies. The study selection results were presented through a flowchart. For the meta-analysis, the authors considered adjusted data. In some cases, crude estimates were used. Heterogeneity was estimated using the I2 statistic. The 'meta' package was used for the meta-analysis.Results Ten studies were included in the meta-analysis. Drug use was associated with higher risk of periodontal disease (OR 1.44; 95% CI 0.8-2.6) and higher DMFT index (OR 4.11; 95% CI 2.07-8.15).Conclusions The review showed high risk of periodontal disease and caries among people who use drugs. The authors concluded that this association may be explained by irregular tooth brushing and long history of drug use. It is important to develop programmes that aim to improve oral hygiene practices among people who use drugs.