SURFACE ULTRASTRUCTURE OF RAT MOLAR TEETH AFTER EXPERIMENTALLY-INDUCED EROSION AND ATTRITION

Young Osborne-Mendel rats were given different diets for 6 weeks. Effe cts of soft and rough food as well as acidic sport drink on the lingua l surfaces of first mandibular molars were studied. In addition, the e ffect of fluoride on erosion was examined. A Jeol JSM-35 scanning elec tron microscope was used to visualize tooth surface ultrastructure. In tact surfaces were found in the rats given soft food and distilled wat er. Sport drink (pH 3.2) caused severe erosion with total loss of supr agingival enamel and exposure of dentin. Attrition effects were seen o n the cuspal parts of the surface when rough food was given. Tooth tis sue loss was greatest in the rats given rough food and sport drink; si gns of both erosion and attrition could be seen. When fluoride was add ed to the sport drink erosion lesions were less severe and if dentin w as exposed, the dentinal tubules were partly occluded. These SEM obser vations support earlier studies which have suggested that erosion may alter tooth surface so that it is more susceptible to attrition; in th ose lesions, however, clinical diagnosis of the initial causes may be difficult.