Alveolar ridge maintenance with hydroxylapatite ceramic cones in humans.

The efficacy of solid cones of hydroxylapatite ceramic implanted in fresh extraction sockets for the preservation of alveolar bone was evaluated. Ten experimental subjects (70 implants) and eight control subjects (63 extractions) were treated. After extraction, hydroxylapatite ceramic cones were inserted into the sockets at least 1 mm below the alveolar crest in the experimental group. Alveolar ridge resorption was measured on lateral cephalometric radiographs, and statistical analysis was performed. The follow-up periods ranged from 12 to 24 months (mean, 20.6 months). Thirty-seven of the 70 hydroxylapatite ceramic cone implants (53%) became exposed, and 19 cones (27%) had to be removed. It was concluded that hydroxylapatite ceramic cone implants placed in fresh extraction sockets do not significantly preserve alveolar bone.