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Bone response to free form-fabricated hydroxyapatite and zirconia scaffolds: a histological study in the human maxilla.

OBJECTIVES
Synthetic and biological materials are increasingly used to provide temporary or permanent scaffolds for bone regeneration. This study evaluated the effect of material chemistry and microporosity on bone ingrowth and osseointegration of zirconia (ZrO(2)) and hydroxyapatite (HA) scaffolds in the human maxilla.


MATERIAL AND METHODS
Twelve patients subjected to dental implant placement were enrolled in the study. Scaffolds of ZrO(2) and HA were placed in the maxilla of each subject, using a randomization protocol. After 3 months of healing, biopsies were harvested comprising the scaffolds and surrounding bone tissue. The biopsies were processed for histological evaluation and morphometric analysis (bone ingrowth and bone-to-scaffold contact).


RESULTS
Healing was uneventful in all cases. All scaffolds demonstrated a measurable bone response using light microscopy and scanning electron microscopy. Microporous HA scaffolds revealed four times larger bone ingrowth and seven times larger bone contact as compared with ZrO(2) scaffolds.


CONCLUSION
The results show that chemistry and microporosity of HA promote bone ingrowth and bone contact of ceramic scaffolds in human maxilla.