Surface ultrastructure of rat molar teeth after experimentally induced erosion and attrition.

Young Osborne-Mendel rats were given different diets for 6 weeks. Effects of soft and rough food as well as acidic sport drink on the lingual surfaces of first mandibular molars were studied. In addition, the effect of fluoride on erosion was examined. A Jeol JSM-35 scanning electron microscope was used to visualize tooth surface ultrastructure. Intact surfaces were found in the rats given soft food and distilled water. Sport drink (pH 3.2) caused severe erosion with total loss of supragingival enamel and exposure of dentin. Attrition effects were seen on the cuspal parts of the surface when rough food was given. Tooth tissue loss was greatest in the rats given rough food and sport drink; signs of both erosion and attrition could be seen. When fluoride was added to the sport drink erosion lesions were less severe and if dentin was exposed, the dentinal tubules were partly occluded. These SEM observations support earlier studies which have suggested that erosion may alter tooth surface so that it is more susceptible to attrition; in those lesions, however, clinical diagnosis of the initial causes may be difficult.