OBJECTIVES: To assess the enamel-protective potential of a newly devised adhesive patch when used as a smooth surface sealant. METHODS: Eighty enamel discs were prepared from bovine lower central incisors and then irradiated. Twenty specimens were treated with one of three sealing options: enamel bond in a two-step application, the prototype of an adhesive patch, or a flowable resin. Unsealed enamel served as positive controls. Loss of apatite was determined using a radiochemical liquid scintillation method after immersion of the samples in saliva or lactic acid (n=10 per treatment group) each for up to 21 days, during which this experimental and control enamel surfaces were exposed to ten toothbrush strokes per day. Quantitative liquid scintillation data were verified by polarized light microscopy. RESULTS: With lactic acid exposure, a double layer of enamel bonding showed better enamel protection than untreated controls, but was significantly less effective than the adhesive patch or filled composite (P<0.05). No significant differences were noted between the latter two treatments. SIGNIFICANCE: It was concluded that the adhesive patch under investigation merits further studies to assess its potential as an inter-proximal sealant.