CLINICAL USE
The phycogenic (algae derived) hydroxyapatite has been in clinical use for over thirty years and has proved to be an excellent augmentation material. It has a wide indication spectrum especially in Cranio - Maxillofacial Surgery. The most important applications are:• grafting periodontal defects (case 1)
• socket grafting ("socket fill", case 2 and 3)
• grafting of large cystic defects (case 4)
• augmentation of large jaw defects before implantation (case 5)
• "sinus-elevation" (case 6)
The bone forming material can be indication-specifically applied either alone or in combination with autogenous (collector -) bone as well as with platelet rich plasma (PRP) in order to enhance the osteoneogenesis. The augmented area should always be covered either with a resorbable or a non resorbable membrane.
Histological studies show, that the apatite material undergoes a mainly cellular successive bone resorption and simultaneously remodelling (creeping substitution) where the product is completely degraded and replaced by newly formed bone. Few months after augmentation the apatite granules are incorporated into a young newly formed vascularized bony tissue. The special porous structure enables the ingrowth of bone cells into the bone substitute particles leading to an intraporous bone growth.
Long-term clinical observations show that the complete resorption-time of the phycogenic apatite is approximately between two and five years. The continuous degradation of the bone forming material and the parallel proceeding of osteoneogenesis guarantees the desired volume-constancy in the augmentation-area.
Retrospective clinical long-term case studies of sinus-elevations over an observation period of 12-14 years showed an implant-survival rate of 95,6 % and in cases with very severe maxillary atropy with iliac bone graft interposition (Horse-shoe-Le fort I Osteotomy) using the phycogenic apatite to stabilize the autogenous transplant, an implant-survival rate of 91,1 %.