Nails and Teeth as Biomarkers of Fluoride Exposure
Condition: Fluorosis, Dental
MeSH terms: Fluorosis, Dental; Fluoride Poisoning
Study type: Interventional

Summary: 
      To determine fluoride concentration in fingernails and estimate if there is a correlation
      between fluoride concentration in fingernails and fluoride concentration in toothpaste used.
      In addition, fluorosis of permanent incisors will be evaluated at 13 years of age and
      correlated with toothpaste fluoride concentration.
    

Detailed description: 
      Toothpaste with 1000 ppm fluoride and above are more effective in a caries prevention in
      comparison to toothpastes with lower fluoride concentration or to placebo. Higher fluoride
      concentrations in toothpastes increase risk for development of tooth fluorosis. Children in
      first three years of life are most susceptible due to formation of permanent incisors and
      first molars in this period, beside younger children ingest more toothpaste compared to older
      children. Fluoride exposure can be measured in nails, where the average plasma fluoride
      concentration is reflected. The aim of our study was to determine fluoride concentration in
      fingernails and estimate if there is a correlation between fluoride concentration in
      fingernails and fluoride concentration in toothpaste used. In our study were included parents
      and children who had participated in previous studies from parenting class until children's 3
      years of age. At that time children were randomly assigned to one of two groups, of which one
      was being given a toothpaste with 500 ppm fluoride and the other with 1000 ppm fluoride.
      Children were examined regularly until the age of 3. Children were invited to participate in
      another clinical examination at 4 years of age. At the time of examination parents were asked
      to fulfil a questionnaire about oral hygiene habits and a sample of children's fingernails
      were taken. A questionnaire fulfilled 200 parents, 169 children were examined, finger nail
      fluoride was analysed by using a gas chromatography method in 161 children. We determined
      that in 76 % the toothpaste chosen was not appropriate according to EAPD guidelines, 66 %
      parents was using toothpaste with 500 ppm fluoride for their children. The mean fingernail
      concentration was 1,43 ng/mg (SD = 0,08). The difference between groups using toothpastes
      with different fluoride concentrations, and compared with other factors, was not
      statistically significant. The mean concentration of fluoride in nails of our test group was
      low compared to reported values in similar studies and there was no significant difference
      between groups regarding to toothpaste used.

      In addition, fluorosis of permanent incisors will be evaluated at 13 years of age and
      correlated with toothpaste fluoride concentration.
    

Intervention name(s): Biodent Toothpaste (Ilirija d.d., Ljubljana, Slovenia)
Intervention type(s): Device
Intervention description(s): Toothpaste with 500 or 1000 ppm of fluoride
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Two parallel groups with different toothpaste fluoride concentrations (500 ppm, 1000 ppm)
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Prevention
Keywords: Dental fluorosis; Fingernails fluoride concentration; Fluoride toothpaste concentration