Effects of low and high fluoride levels on rat dental caries and simultaneous dentine apposition.
The effects of various fluoride levels in drinking water on the development of enamel and dentinal caries and on dentine apposition were determined in Osborne-Mendel rats fed ad libitum either on a 43% sucrose diet and distilled water supplemented with 0, 1, 7 or 19 parts/10(6) fluoride, or on a non-cariogenic diet. The jaws were sectioned sagittally and fissure caries was assessed. The areas of the dentinal lesions and simultaneously formed dentine were quantified after tetracycline staining. There were fewer and smaller caries lesions in all fluoride groups than in the non-fluoride groups. The anti-caries effects of fluoride at 1 and 7 parts/10(6) were similar, but both had significantly less effect than 19 parts/10(6) fluoride. Much smaller dentinal lesions were seen with 19 parts/10(6) fluoride, which appears to have been accompanied by an even greater reduction in dentine apposition. Dentine formation in the third molars was significantly reduced in the rats fed a cariogenic diet. These observations suggest that a high-sucrose diet interferes with the formation of dentine in the developing tooth. Fluoride has a multiple effect; besides reducing the formation and progression of caries, it may also affect the dentinal response normally seen in the development of a caries lesion.
Kortelainen
S
S
Institute of Dentistry, University of Oulu, Finland.
Larmas
M
M
D000818:Animals; D003731:Dental Caries / Q000378:metabolism* / Q000473:pathology; D003743:Dental Enamel / Q000378:metabolism* / Q000648:ultrastructure; D003804:Dentin / Q000648:ultrastructure; D003809:Dentin, Secondary / Q000139:chemically induced; D003810:Dentinogenesis / Q000187:drug effects; D004037:Diet, Cariogenic; D005459:Fluorides / Q000008:administration & dosage*; D008963:Molar; D051381:Rats; D011919:Rats, Inbred Strains
D005459:Fluorides