Morphological effects produced, in vitro, by ferric oxalate treatment of enamel surfaces. A preliminary SEM study

The morphological changes produced, in vitro, by application of ferric oxalate on enamel surfaces were examined by scanning electron microscopy. Exposure of human enamel surfaces to ferric oxalate (5.3% w/w aqueous solution or added to phosphoric or citric acid) resulted in cleaned, activated enamel surfaces and a mild etching which increased surface roughness and porosity. Deposition of crystal formations occurred in approximately 50% of the examined areas. Crystals bond firmly to the porous underlying surfaces and resist washing with 5, 10 or 20 ml of distilled water.