Formal influential opinions on hygiene of teeth to prevent caries / actions taken to improve condition of teeth of school children / giving advice / how to keep teeth in order / opinions on fluoridation of water / role of eating sweets / giving information on keeping teeth clean / mothers' opinions on fluoridation / the condition of teeth of school children in general / control of conditions of teeth of own child / how to improve that condition / opinions on sweets / relation parent-child in relation to teeth condition / interest in teeth hygiene / role of school and doctors / knowledge of slogans / child and medication / vitamins / hygiene / emotional relation to child. Background variables: basic characteristics/ household characteristics/ occupation/employment/ education