HYDROXYLAPATITE AUGMENTATION OF ATROPHIC ALVEOLAR RIDGE.

Dense nonresorbable forms of hydroxylapatite (HA) have been developed in particulate and block forms. Clinical uses include correction of periodontal defects, preservation of alveolar ridge, reconstruction of atrophic ridge, interpositional bone substitutes in reconstructive and orthognathic surgery and as a bone graft extender in maxillary and mandibular defects. HA, a highly biocompatible, osteoconductive calcium phosphate material has provided a permanent support matrix for deposition of fibrous tissue and bone by direct chemical bonding mechanisms. In 1978 our institution initiated prospective clinical trials for ridge reconstruction with dense particulate HA. The use of particulate hydroxylapatite for ridge augmentation has demonstrated a significant improvement over other techniques, as evidenced by up to five years of follow-up in our patients. Denture construction begins as early as 3 to 4 weeks post augmentation. Stability is improved and relines and remakes are less frequent compared to patients who have been augmented with autogenous bone alone. Skin and mucosal graft vestibuloplasties are often possible 2 months post augmentation compared to 4 to 6 months post augmentation following autogenous bone grafts alone. In most patients augmentation of alveolar deficient ridges with HA has resulted in a permanent improved ridge height and convex contour.