Povidone Iodine to Prevent Early Childhood Caries

Dental 'caries' is the term used to describe dental decay or 'cavities'. Dental caries can occur at any age but lesions prior to a child's 6th birthday qualify as 'early childhood caries' (ECC) and possibly as 'severe' early childhood caries (SECC) if the onset and severity meet definitions put forth by the American Academy of Pediatric Dentistry. ECC and SECC can have several unfortunate downstream consequences: pain, infection, nutritional deficiencies, poorer concentration in school, and social/cosmetic/financial concerns. Recent epidemiologic trends in ECC/SECC, reported by Kotha et al. (2022) based on data from the National Health and Nutrition Examination Survey (NHANES), have found little change in prevalence over the span from 2013 to 2018 with approximately 20% of children experiencing ECC by age 3 years with over half that percentage categorized as having SECC. Thus, there remains a critical need to improve prevention and treatment strategies.

Many variables can affect the likelihood of developing dental decay but prominent among these are excess consumption of sugary foods and drinks, inadequate oral hygiene, and poor access to dental care and oral health educational resources. Ultimately, microbes on the surface of teeth convert dietary sugar to acid that dissolves enamel thereby initiating and advancing decay. Brushing regularly with fluoridated toothpaste helps suppress the microbial population which decreases the acid challenge while fluoride promotes remineralization of enamel. Seeing a dentist regularly can ensure that any decay that develops is treated at its earliest stages thereby saving teeth.

While prevention strategies work well for many individuals, for a multitude of potential reasons they may prove inadequate for others. In particular, children with poor access to professional care or who are disadvantaged in other respects frequently fail to realize the benefits of the current standard of care.

The objective of this investigation is to test the effectiveness of povidone iodine (PI) as a home-administered preventive or treatment for dental caries that, unlike other treatment options, addresses the underlying cause - dental plaque that has an overabundance of strong acid-producing bacterial species. This imbalance of strong acid producers is referred to as a 'dysbiosis'. We will also test whether combining PI with probiotics - living microbes that can be used to boost health - will have a greater benefit than PI alone in maintaining or restoring a healthy microbial composition to dental plaque. We are in a unique position to leverage our access to children at high risk for decay to test multiple integrated hypotheses that we predict will result in more effective home dental care, and significant reductions in the incidence and severity of dental decay that is longer lasting than is possible with the current standard of care.

Despite tremendous advances in understanding how particular microbes in dental plaque lead to tooth decay, prevention and treatment options remain non-specific - dedicated to plaque control rather than to replacing the offending microbes with health-related species (correcting the dysbiosis). This limitation results in the chronic presence of an elevated microbial risk that likely proves most consequential in individuals with limited access to professional care and suboptimal oral hygiene habits. Importantly, PI is unique among current standard of care options because there is evidence that it not only can prevent caries but that it also attacks the microbial offenders that drive caries development. The addition of fluoride to water supplies and oral health care products was a game-changer. Protection appears to be due to improving the enamel remineralization/demineralization balance rather than any antimicrobial activity despite in vitro evidence of selective toxicity against S. mutans.