What do systematic reviews say?

External control of fluoride concentration vs Not applicable

In the Northeast region, 0.2% of samples were above the acceptable range.

• External control of fluoridation in the public water supplies of Brazilian cities as a strategy against caries: a… 2021 All outcomes

  1995-2013 · Brazilian Northeast · Northeast region
  Prevalence 0.2
  Studies not reported
  GRADE not reported

Fluoride concentration relative to the acceptable range (electrometric ion-selective electrode measurement; acceptable range mostly 0.6-0.8 ppmF) vs None (descriptive proportion meta-analysis)

In the Southeast Brazilian region, a pooled 11.5% of water samples had fluoride above the acceptable range; ungraded.

• External control of fluoridation in the public water supplies of Brazilian cities as a strategy against caries: a… 2021 All outcomes

  Public water supply / water treatment stations in Brazilian cities (external control of artificial fluoridation) · Region: Southeast Brazil
  Prevalence 11.5
  Studies not reported
  GRADE not reported
• External control of fluoridation in the public water supplies of Brazilian cities as a strategy against caries: a… 2021 All outcomes

  Public water supply / water treatment stations in Brazilian cities (external control of artificial fluoridation) · Region: Northeast Brazil
  Prevalence 0.2
  Studies not reported
  GRADE not reported

Intervention not reported

• External control of fluoridation in the public water supplies of Brazilian cities as a strategy against caries: a… 2021 All outcomes
  Prevalence 6.7
  12 studies
  GRADE not reported

Intervention not reported

• External control of fluoridation in the public water supplies of Brazilian cities as a strategy against caries: a… 2021 All outcomes

  Region: South Brazil
  Prevalence 12.7 [0.5, 36.6]
  Studies not reported
  GRADE not reported