Study	Reason for exclusion
Antia 1974	Random or quasi‐random allocation not stated.
Axelsson 1976	Additional fluoride‐based intervention associated to fluoride toothpaste. Blind outcome assessment not stated.
Bibby 1945	Random or quasi‐random allocation not stated or indicated. Blind outcome assessment not stated or indicated.
Bixler 1962	Group of participants more than 16 years old selected. Random or quasi‐random allocation not stated.
Bixler 1966	Group of young adults selected.
Bixler 1966a	Additional fluoride‐based intervention associated to fluoride toothpaste. Group of participants more than 16 years old selected. Blind outcome assessment not stated.
Downer 1976	Additional fluoride‐based intervention associated to fluoride toothpaste.
Ennever 1980	Random or quasi‐random allocation not stated or indicated.
Finn 1963	Medically compromised group of institutionalised children selected.
Gish 1965	Additional fluoride‐based intervention associated to fluoride toothpaste. Blind outcome assessment not stated.
Gutherz 1968	Random or quasi‐random allocation not stated or indicated. Blind outcome assessment not stated or indicated.
Halikis 1966	Random or quasi‐random allocation not stated or indicated.
Hill 1959	Random or quasi‐random allocation not stated or indicated. Blind outcome assessment not stated or indicated.
Jiraskova 1965	Random or quasi‐random allocation not stated or indicated. Blind outcome assessment not stated or indicated.
Jordan 1959	Only two clusters (schools), each randomised to one of the two interventions compared.
Kunzel 1977	Additional fluoride‐based intervention associated to fluoride toothpaste.
Lehnhoff 1966	Participants more than 16 years old selected.
Lu 1985	Additional active agent associated to fluoride in toothpaste.
Luoma 1978	Additional fluoride‐based intervention associated to fluoride toothpaste.
Mergele 1968a	Medically compromised group of institutionalised young adults and children selected.
Moller 1968	Additional active agent associated to fluoride in test toothpaste.
Muhler 1955a	Random or quasi‐random allocation not stated.
Muhler 1957	Random or quasi‐random allocation not stated.
Muhler 1958	Participants more than 16 years old selected. Random or quasi‐random allocation not stated.
Muhler 1960	Participants more than 16 years old selected. Random or quasi‐random allocation not stated. Blind outcome assessment not stated.
Muhler 1962	Participants more than 16 years old selected.
Niwa 1975	Random or quasi‐random allocation not stated or indicated. Blind outcome assessment not stated or indicated.
Onisi 1970	Random or quasi‐random allocation not stated or indicated. Blind outcome assessment not stated or indicated.
Onisi 1974	Additional active agent associated to fluoride in toothpaste. Only two clusters (villages), each assigned to one of the two interventions compared.
Patz 1970	Participants more than 16 years old selected. Blind outcome assessment not stated.
Peffley 1960	Participants more than 16 years old selected. Random or quasi‐random allocation not stated. Blind outcome assessment not stated.
Piccione 1979	Blind outcome assessment not stated or indicated.
Riethe 1975	Blind outcome assessment not stated or indicated.
Stookey 1975	Random or quasi‐random allocation not stated.
Wrinkler 1953	Random or quasi‐random allocation clearly not used (non‐random concurrent control: by matching procedure).
Zickert 1982	Additional fluoride‐based intervention associated to fluoride toothpaste.