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 s urface treatments and electrode area size on the corrosion of cast and machined titanium in contact with conventional and high-copper amalga ms in saline solutions with and without added fluoride ions. Methods. The potentials and the charges transferred between amalgam and titaniu m couples were registered using standard electrochemical methods. Resu lts. Conventional amalgam corroded more than high-copper amalgams in c ontact with titanium in saline solutions. Adding fluoride to the solut ion made the titanium potential more active and enhanced the corrosion of titanium in combination with high-copper amalgams. The amalgam cor rosion increased with a five-fold enlargement of the titanium area. Th e increase was significant for one titanium-amalgam combination. Surfa ce preparations affected the electrochemical behavior, and surface alt erations 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.