The effect of oral topical fluorides on the surface of commercially pure titanium.

This study investigated the risk of corrosion of titanium abutments by the accidental or unauthorized use of preventive fluorides in the mouth. Polished test pieces of commercially pure ASTM grade 1 titanium were immersed in topically used fluorides (toothpaste, gel, and varnish). They were brushed in vitro with toothpaste and gel, corresponding to the time and effect of brushing with toothpaste twice a day for 6 years and with gel once a week for 12 years. Results indicate that an aminofluoride toothpaste with low ionizable fluoride content (0.125%) used in brushing natural teeth does not cause deterioration of the titanium abutments in the same mouth if the titanium is grade 1 purity. Carefully controlled use of fluoride gel (F 1.25%) and varnish (F 2.25%) is likewise not dangerous. The mechanical abrasion caused by toothbrush bristles appears to be the main deteriorating factor for the titanium surface.