HYDROXYLAPATITE AUGMENTATION OF ATROPHIC ALVEOLAR RIDGE

Abstract

This chapter discusses the hydroxylapatite augmentation of atrophic alveolar ridge. Hydroxylapatite (HA), a highly biocompatible, osteoconductive calcium phosphate material has provided a permanent support matrix for the deposition of fibrous tissue and bone by direct chemical bonding mechanisms. In some of the class III and IV ridge deficiency patients, 12–20 grams of HA mixed with finely crushed autogenous cancellous iliac bone was used to provide increased strength to the severely atrophic alveolar ridges. Surgical technique involved subperiosteal pocket tunneling through vertical mucoperiosteal incisions with or without a blind submucosal vestibuloplasty. Injection of HA into these pockets was done with a variety of modified plastic syringes. Solidification of HA generally occurred by the fourth to sixth postoperative week permitting impressions for denture construction. Skin and mucosal graft vestibuloplasty, if needed to increase sulcus depth after hydroxylapatite augmentation, was usually possible after two months because of the intense fibrous tissue infiltration between HA particles. In most patients augmentation of alveolar deficient ridges with HA has resulted in a permanent improved ridge height and convex contour. The overlying soft tissue mucosa is nonmobile except in severe ridge deficiencies where post operative vestibuloplasties are required.