Which upstream interventions are effective for promoting oral health and reducing inequalities?

Background: Upstream interventions adopt population approaches to address underlying structural and social causes of health inequalities. Evidence has shown limited long-term effectiveness of downstream clinical interventions to reduce oral health inequalities, but little is known regarding impacts of upstream interventions.

Objective: This scoping review aimed to identify and review literature on upstream interventions which may promote oral health and/or reduce socioeconomic oral health inequalities.

Methods: Searches were conducted on databases (ASSIA, CINAHL, PsycINFO, Medline, Embase, Cochrane Database of Systematic Reviews, Scopus), grey literature sources (OpenGrey, WorldCat, NICE Evidence search, EThOS, Trip, and NTIS: Technical Reports), alongside websites of relevant public health organisations. Searches included data published prior to October 2021. Articles examining upstream population-wide polices or upstream interventions targeted at population groups were assessed. Articles published in languages other than English were also included following translation. Two independent reviewers screened and extracted data from eligible articles for review.

Results: Eighty-four articles were identified, including 21 systematic reviews. Few of the upstream interventions identified specifically focused on promoting oral health and/or reducing socioeconomic oral health inequalities. Some interventions such as fiscal measures (e.g., sugar sweetened beverage/tobacco taxation), legislative/regulatory measures (e.g., advertising control), and specific oral health interventions such as water fluoridation, had positive effects in promoting oral health. The following interventions demonstrated positive impacts for socioeconomic health inequality reduction: fiscal measures (e.g., tobacco taxation), food subsidies targeted at low-income groups, and improvements to housing/work environments. However, the evidence regarding water fluoridation was mixed. Several interventions may have generated inequalities; these included mass media interventions, educational programmes, and regulation to reduce alcohol taxation.

Conclusion: There is limited evidence regarding upstream interventions for oral health promotion and inequality reduction, however, interventions linked to wider social health determinants and those targeted at non-communicable diseases with shared risk factors for oral health may prove positive.