2. Percentage prevalence of fluorosis.

Study	Index used	Prevalence	Remark
RCT
Holt 1994	TFI.	18%
Tavener 2006	TFI.	22%
Cohort study
Franzman 2006	Fluorosis Risk Index.	27%	Fluorosis on 2 or more permanent incisors.
Case‐control study
Osuji 1988	TFI.	13%
Skotowski 1995	TSIF.	72%
Pendrys 1989	Fluorosis Risk Index.	‐‐‐	Not reported.
Pendrys 1994	Fluorosis Risk Index.	‐‐‐	Not reported.
Pendrys 1996	Fluorosis Risk Index.	‐‐‐	Not reported.
Pendrys 1998	Fluorosis Risk Index.	‐‐‐	Not reported.
Cross‐sectional survey
Beltran‐Valadares 2005	Dean's Index.	56%
Bottenberg 2004	TFI.	10%
Brothwell 1999	TSIF.	23%
Conway 2005	TFI.	49%
Do 2007	TFI.	27%
Maupome 2003	TFI.	33%
Mascarenhas 1998	TFI.	13%
Morgan 1998	Dean's Index.	69%
Pereira 2000	TFI.	10%
Riordan 1993	TFI.	48%
Riordan 2002	TFI.	18%
Rock 1997	TFI.	35%
Sagheri 2007	Dean's Index.	26%	Dublin (fluoridated area).
Sagheri 2007	Dean's Index.	18%	Freiburg (non‐fluoridated area).
Szpunar 1988	TSIF.	36%
Tabari 2000	TFI.	54%	Newcastle (fluoridated area).
Tabari 2000	TFI.	23%	Northumberland (non‐fluoridated area).
Wang 1997	TFI.	36%

TFI = Thylstrup and Fejerskov Index; TSIF = Tooth Surface Index of Fluorosis.