Experience and views of caries research and oral health.

The main clinical and theoretical studies on caries etiology and prevention and on general health published by the author and his coworkers since the beginning of the 1960s are briefly reviewed. Among the caries prevention methods published by previous authors, the Finnish trials on fissure sealing and fluoride varnishing showed distinct preventive effects. On the basis of these and later supporting findings, these methods were rapidly and widely adopted in the dental health care of Finnish children and adolescents. A chlorhexidine-fluoride mouthrinsing solution, developed by the author, exhibited simultaneous reduction of both caries and gingivitis among high -risk children and this preparation or chlorhexidine-fluoride gels have been widely prescribed for risk subjects, especially those with a caries risk. Despite the good caries prevention results obtained through fluoridation of sugar products and in respective model studies, this procedure has not been passed for commercial use in Finland. The translocation of phosphorus, potassium and fluoride between microbes of dental plaque origin and their environment, including the respective elements of enamel origin, were presented as a partial explanation for the role of phosphates and fluoride in caries etiology and/or prevention. Animal experiments elucidated the killing mechanism of a high single fluoride intake and its prevention by magnesium with explanatory changes in cardiac calcium. On the other hand, experiments on prolonged intakes of low dietary fluoride by rats confirmed earlier findings on the potential of fluoride in preventing calcium salt imbalances in internal organs. This was accomplished with a fluoride intake sufficient for caries reduction. The ability of two strains of the mutans streptococci and a Lactobacillus to invade enamel and dentine and to destory these structures from the inside before the cavitation phase of caries was demonstrated with gnotobiotic rats. The marked caries reduction among Finnish children and adolescents within the past 20 years appears to be due to a number of factors.