Reassessment of long-term use of dense HA as dental implant: case report.

Dense hydroxyapatite (HA) is widely believed to be unsuitable for clinical use as dental implants due to its poor mechanical properties, although it has excellent biocompatibility and is chemically stable and nonresorbable in vivo. However, the case in this article is one in which the patient's dense HA implants are still stable and in good functional condition 16.5 years after he received four pieces of a one-piece dense HA implant in both sides of his lower molar regions. Furthermore, almost no radiolucency is evident along the root portions of the implant sites in the bone. These findings imply that dense HA can be clinically useful and should be reevaluated as a dental implant material.