Metal ion release from metallic implants is known to occur, but its extent and implications are controversial. In spite of the rapidly growing use of such implants, little is known about metal ion release. Blood levels of titanium, aluminum, and vanadium were measured using an atomic absorption spectrophotometric technique preoperatively and at intervals over a 3-year period for 52 patients (17 men, 35 women), each of whom had three mandibu lar porous-surface endosseous dental implants. The results showed that there was no evidence of change from preoperative to long-term values for the three metals measured in the study. These findings are reassuring, but do n ot rule out local or remote accumulation of released ions, which was not measured in this study.