Scand. J. Dent. Res. 1975: 83: 13-17 (Key word,>;: apatites; fluoride; fruit juice; tooth, erosion)
Degrees of saturation with respect to apatites iri fruit juices and acidic drinks M, JOOST LARSEN Department of Dental Pathology and Operative Dentistry, Royal Dental College, Aarhus, Denmark ABSTRACT - Some fruit juices and carbonated acidic drinks, recognized as agents causing dental erosions, were analyzed for calcium, phosphate, fluoride and pH, Ionic activity/concentration products for hydroxyapatite and fluorapatite were calculated. It was found that all liquids analyzed were unsaturated with respect to both apatites, which explains their erosive effect. {Received for publication 27 September, accepted 15 October 1974)
Dental erosive lesions include three types of injuries. Formation of dietary erosions has been ascribed to excessive intake of acidic beverages, acidic fruits and fruit juices, while occupational erosions are induced by airborne acid dusts to which workers in certain industries are exposed. These two types of erosions most often affect the front teeth. The third type of erosion, perimylolysis, caused by vomit or pyrosis, is observed primarily on the palatal aspects of the maxillary teeth (PINDBORG 1970). Clinically, the erosion appears as a hollowing of the affected surfaces, rendering the lesions saucer-shaped or, in the case of occupational and perimylolytic erosions, resulting in a reduction of the crown height, while resistant fillings and inlays appear as "rocky islands" (PINDBORG 1970). Thus, the mineral loss is different from that observed in the carious lesion
where, in the initial stages, an intact enamel surface layer remains while the subsurface, is being demineralized. In the laboratoiy, enamel can be dissolved under two chemically distinct conditions. When the liquid phase is unsaturated with respect to both hydroxyapatite and fluorapatite, both apatites dissolve coincidently, the resulting lesion being a surface etching. In contrast, when the liquid phase is supersaturated with respect to fluorapatite and unsaturated with respect to hydroxyapatite, the former salt is formed while the latter dissolves, the resulting lesion being very like a caries lesion (LARSEN 1974
a,b).
As acidic drinks and fruit juices are believed to have an erosive effect, it was considered of interest to study the degrees of saturation with respect to hydroxyapatite and fluorapatite in these liquids.
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Degrees of saturation with respect to apatites iri fruit juices and acidic drinks M, JOOST LARSEN Department of Dental Pathology and Operative Dentistry, Royal Dental College, Aarhus, Denmark ABSTRACT - Some fruit juices and carbonated acidic drinks, recognized as agents causing dental erosions, were analyzed for calcium, phosphate, fluoride and pH, Ionic activity/concentration products for hydroxyapatite and fluorapatite were calculated. It was found that all liquids analyzed were unsaturated with respect to both apatites, which explains their erosive effect. {Received for publication 27 September, accepted 15 October 1974)
Dental erosive lesions include three types of injuries. Formation of dietary erosions has been ascribed to excessive intake of acidic beverages, acidic fruits and fruit juices, while occupational erosions are induced by airborne acid dusts to which workers in certain industries are exposed. These two types of erosions most often affect the front teeth. The third type of erosion, perimylolysis, caused by vomit or pyrosis, is observed primarily on the palatal aspects of the maxillary teeth (PINDBORG 1970). Clinically, the erosion appears as a hollowing of the affected surfaces, rendering the lesions saucer-shaped or, in the case of occupational and perimylolytic erosions, resulting in a reduction of the crown height, while resistant fillings and inlays appear as "rocky islands" (PINDBORG 1970). Thus, the mineral loss is different from that observed in the carious lesion
where, in the initial stages, an intact enamel surface layer remains while the subsurface, is being demineralized. In the laboratoiy, enamel can be dissolved under two chemically distinct conditions. When the liquid phase is unsaturated with respect to both hydroxyapatite and fluorapatite, both apatites dissolve coincidently, the resulting lesion being a surface etching. In contrast, when the liquid phase is supersaturated with respect to fluorapatite and unsaturated with respect to hydroxyapatite, the former salt is formed while the latter dissolves, the resulting lesion being very like a caries lesion (LARSEN 1974
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