Human caries vulnerability: Is this affected by restorations or cavities at adjacent surfaces?

Abstract

Silicate restorations contain fluoride. A sound enamel surface on one tooth, adjacent to a silicate restoration on another, might be expected, therefore, to receive some measure of protection from attacks of caries. We test this “protection hypothesis”. An unrestored cavity forms a zone of stagnation. Hence, an initially sound enamel surface on one tooth, adjacent to an unrestored cavity on another, should be rendered especially vulnerable to caries attack. This “stagnation hypothesis” is also tested. The relative frequencies of sound, decayed and filled sites are determined, by age, at adjacent mesial and distal surfaces on maxillary incisor teeth. In addition, the relative frequency with which a sound surface faces: (a) an adjacent restored site, (b) an adjacent unrestored site, is also determined in relation to age. Data from the North East of England and from Gloucestershire are analysed separately. They fail to verify the predictions of both “protection” and “stagnation” hypotheses. The implications of the findings to the aetiology and pathogenesis of dental caries are discussed.