Fluoride Action Network


We tested the effect of an annual caries preventive intervention, delivered by a fly-in/fly-out oral health professional team, with Indigenous children residing in a remote Australian community. Around 600 Indigenous children aged 5 to 17 years were invited to participate at baseline, of who 408 had caregiver consent. One hundred and ninety-six consented to the epidemiological examination and intervention (Intervention group) and 212 consented to the epidemiological examination only (Comparison group). The intervention, which occurred annually, comprised placement of fissure sealants on suitable teeth, and application of povidone-iodine and fluoride varnish to the whole dentition, following completion of any necessary restorative dental treatment. Standard diet and oral hygiene advice were provided. Caries increment (number of tooth surfaces with new dental caries) in both deciduous and permanent dentitions was measured at the 2-year follow-up. Comparison group children had significantly higher number of new surfaces with advanced caries in the permanent dentition than the Intervention group (IRR = 1.61; 95% CI: 1.02–2.54; p = 0.04); with a preventive fraction of 43%. The effect of intervention remained significant with children in the Comparison group developing significantly more advanced caries lesions in the permanent dentition than the Intervention group children in the adjusted multivariable analysis (IRR = 2.21; 95% CI: 1.03–4.71). Indigenous children exposed to the intervention had less increment in advanced dental caries in the permanent dentition than those not exposed to the intervention.

*Full article online at https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0244927



… While our annual intervention reduced caries incidence, caries increment remains unacceptably high in this community, even in children who received it. These interventions are resource-intensive, so consideration should be given to proven cost-effective interventions such as the reintroduction of water fluoridation. If active interventions are needed, consideration should be given to expanding the roles of community health workers to deliver preventive programs, especially minimally invasive interventions such as povidone-iodine applications and fluoride varnish. In remote communities it would not be feasible or sustainable for these to be delivered by oral health professionals. If performed by trained community health workers, more regular applications as normally recommended would be feasible [21].

Besides introducing active (professionally-applied) and passive (water fluoridation) interventions, it is of critical importance to address social determinants to reduce the burden of poor oral health [22]. For example, consumption of sugar-sweetened beverages is of serious concern in Indigenous communities, with increases occurring during adolescence [23]. Strategies to reduce sugar consumption include taxes on sugar and/or sugar-sweetened beverages [24], and graphic warnings on labels [25]. It is incumbent upon dental researchers, dental providers and policy-makers to advocate for public health interventions to address the upstream social determinants of health that have the most impact on the oral and general health [26].

At this is a non-randomised trial, lacking a prospective randomised recruitment, assessing the true effect of the preventive intervention is compromised. The two groups for example showed pre-existing differences at baseline. Longitudinal studies, especially in remote settings, have limitations. One such is loss to follow-up of participants. In our community there are a number of reasons: obtaining parent/guardian consents is always challenging, not necessarily because there is opposition, often simply because carers cannot be located or motivated. Here, this was compounded by the need to obtain multiple signed consents: for epidemiological examinations; for application of our preventative intervention, for treatment planning examinations and for restorative treatments. Similarly, compliance to all stages of clinical contact is often poor, because students are absent from school or out of the community for social or family reasons. School absenteeism is common and it is an important goal of government to improve this [27]. In 2015, at baseline, school attendance was high as there was a community effort to encourage this. At follow-up visits this effort had waned and absenteeism was higher. Some children, especially later into their schooling, move to larger towns to complete their education. While we lost a number of children to follow up over the 2-years of the study, the findings from the per-protocol and ITT analysis showed no differences. While clinical examiners were not informed of the group status of children who attended follow-up, the presence of fissure sealants made blinding impossible. With each examination time point separated by a year, deciduous teeth that developed caries, but exfoliated and were replaced by permanent teeth between these time points would have underestimated caries increment in the deciduous dentition.

While it is important to address the social determinants of health in Indigenous communities in Australia, it is critically important that at a national level there is progress on the broader issues of Indigenous disadvantage and dispossession of land and resources. Many argue for formal recognition of the Aboriginal and Torres Strait Islander peoples in the Nation’s constitution, for a formal treaty to acknowledge the impact of colonisation and a Makarrata: the coming together after a struggle [28], all of which impact on oral health, oral health-related quality of life and overall health and well-being.

References for above

  • 21. NT Health. Healthy Smiles training program summation report. Darwin: 2017.
  • 22. Arantes R, Welch JR, Tavares FG, Ferreira AA, Vettore MV, Coimbra CEA Jr. Human ecological and social determinants of dental caries among the Xavante Indigenous people in Central Brazil. PLoS One. 2018;13(12):e0208312. Epub 2018/12/20. pmid:30566453; PubMed Central PMCID: PMC6300322.
  • 23. Cockburn N, Lalloo R, Schubert L, Ford PJ. Beverage consumption in Australian children. Eur J Clin Nutr. 2018;72(3):401–9. Epub 2017/12/01. pmid:29187750.
  • 24. Waterlander WE, Ni Mhurchu C, Steenhuis IH. Effects of a price increase on purchases of sugar sweetened beverages. Results from a randomized controlled trial. Appetite. 2014;78:32–9. pmid:24667153.
  • 25. Donnelly GE, Zatz LY, Svirsky D, John LK. The Effect of Graphic Warnings on Sugary-Drink Purchasing. Psychol Sci. 2018;29(8):1321–33. pmid:29912624.
  • 26. Watt RG, Daly B, Allison P, Macpherson LMD, Venturelli R, Listl S, et al. Ending the neglect of global oral health: time for radical action. Lancet. 2019;394(10194):261–72. Epub 2019/07/23. pmid:31327370.
  • 27. Australian Government. Closing the Gap—Prime Minister’s Report 2018. Chapter 3—Education Canberra2018 [cited 2018 17 August]. Available from: https://closingthegap.pmc.gov.au/education.
  • 28. 2017 National Constitutional Convention. ULURU STATEMENT FROM THE HEART. 2017.