Effects of protein deficiency induced by raw soy with and without sucrose on dentine formation and dentinal caries in young rats.
OBJECTIVE
The effects of protein deficiency and sucrose on formation and mineralization of dentine and dental caries in the molars of young rats were investigated.


METHODS
Two groups of weaning Wistar rats received raw soy flour to induce protein deficiency with sucrose or starch as the carbohydrate source; the other two groups received skim milk powder as the protein source with sucrose or starch as the carbohydrate source. At the onset, tetracycline was injected to mark the dentine formed at that moment. After 6 weeks, lower molars were sectioned sagittally, and the areas of dentine formation and dentinal caries developed during the experiment were quantified separately in the first and second molars. Dental caries was also classified according to Schiff's reaction. Calcium (Ca), phosphorus (P) and total mineral elements were analyzed using an electron probe microanalyzer.


RESULTS
Rats in both protein-deficient groups and normal protein sucrose group had significantly larger areas of dentine formed compared with rats fed with normal protein starch diet. Ca, P and total mineral elements in dentine were significantly reduced by normal protein sucrose diet. P content was significantly reduced in dentine of rats in protein-deficient sucrose group. Rats in normal protein sucrose group had significantly more and larger dentinal caries lesions than in any other group.


CONCLUSIONS
This study suggests that protein deficiency induced by soy prevents the progression of dental caries even in highly cariogenic environment.
Huumonen
Sisko
S
Institute of Dentistry, University of Oulu, P.O. Box 5281, Fin-90014, Oulu, Finland. Sisko.Huumonen@odontologi.gu.se
Larmas
Markku
M
D000818:Animals; D002118:Calcium / Q000032:analysis; D002326:Cariogenic Agents; D003731:Dental Caries / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D003810:Dentinogenesis / Q000187:drug effects*; D004037:Diet, Cariogenic; D019422:Dietary Sucrose / Q000494:pharmacology*; D018450:Disease Progression; D004435:Eating; D004577:Electron Probe Microanalysis / Q000379:methods; D005260:Female; D008903:Minerals / Q000032:analysis; D008963:Molar / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D010758:Phosphorus / Q000032:analysis; D011488:Protein Deficiency / Q000150:complications* / Q000209:etiology; D051381:Rats; D017208:Rats, Wistar; D030262:Soybean Proteins; D014886:Weaning; D015430:Weight Gain
D002326:Cariogenic Agents; D019422:Dietary Sucrose; D008903:Minerals; D030262:Soybean Proteins; D010758:Phosphorus; D002118:Calcium