USE OF TRANSVERSE MICRORADIOGRAPHY TO QUANTIFY MINERAL LOSS BY EROSION IN BOVINE ENAMEL

The aim of the present study was to develop transverse microradiograph y (TMR) in order to quantitatively assess the influence of artificial saliva and orange juice on the erosion of bovine enamel. Bovine inciso rs were sectioned sagittally into two equal halves. Each half was coat ed with acid-resistant nail varnish except for a rectangular enamel wi ndow on the labial surface of the tooth. While both halves of each too th were immersed in pure orange juice 6 times daily for a period of 5 min at each occasion making a total of 30 min per day, one half was st ored in artificial saliva and the other half in deionized distilled wa ter between exposures to orange juice and for the remaining 12 h overn ight, for 24 days making a total of 12 h of exposure to orange juice. Sections bearing intact and eroded enamel surfaces were cut from each specimen and ground to 80 mu m thickness, and TMR of the sections was made. Mineral loss was quantified from the microradiographs using two- step image analysis. Mineral loss was significantly greater in those s pecimens cycled in orange juice and de-ionized distilled water. TMR wa s used successfully to quantify the mineral loss by erosion in vitro, and it is envisaged that it will be useful for specimens used in intra -oral appliances during in situ trials. Artificial saliva saturated wi th respect to calcium and phosphate salts can possibly remineralize an erosive lesion and may reduce the degree of erosion.