CORROSION OF TITANIUM AND AMALGAM COUPLES - EFFECT OF FLUORIDE, AREA SIZE, SURFACE PREPARATION AND FABRICATION PROCEDURES

Objectives. The aim of this investigation was to study the effect of surface treatments and electrode area size on the corrosion of cast and machined titanium in contact with conventional and high-copper amalgams in saline solutions with and without added fluoride ions. Methods. The potentials and the charges transferred between amalgam and titanium couples were registered using standard electrochemical methods. Results. Conventional amalgam corroded more than high-copper amalgams in contact with titanium in saline solutions. Adding fluoride to the solution made the titanium potential more active and enhanced the corrosion of titanium in combination with high-copper amalgams. The amalgam corrosion increased with a five-fold enlargement of the titanium area. The increase was significant for one titanium-amalgam combination. Surface preparations affected the electrochemical behavior, and surface alterations were occasionally observed on wet-ground titanium specimens. No significant differences were found in comparisons of cast and lathe-cut titanium. Significance. Surface preparations and fluoride affect the electrochemical activity of titanium.