A Ceramic Drug Delivery System For Bone Augmentation

Objectives:

Bone augmentation for periodontal operative treatment and implantology is still a challenge. The physiological reconstruction of  jawbone is either built up with ceramics or transplants. The induction of bone formation in situ is still a matter of investigation. A new ceramic carrier for BMP is introduced yielding primary cancellous bone, which is finally transferred into compact bone. 

Methods:

A standardized defect (8,35 x 20 mm) has been performed in the patellar groove and the tibiahead of 10 sheep using diamond instruments and a wet grinding technology. The defect was closed towards the joint by a press-fit inserted ß-TCP cover thus avoiding diffusion of the BMP-7. ß-TCP microchambered beads (MCB) with BMP-7 were inserted. Non-demineralized high-resolution-histology after 6 and 9 weeks, 3 months and 1 year was performed.

Results:

After 6 weeks, a primary cancellous scaffold of mature lamellar bone has formed around the ceramic MCBs. There was no ectopic bone formation indicating diffusion of BMP. After 9 weeks, remodelling and ß-TCP resorption was nearly finished. The three months- and one-year results revealed a newly formed bone, spongious in the metaphysis and compact cortical along the diaphyseal tube or epiphyseal compacta. Compared with the plain ceramic, there was a 4-6 weeks faster bone healing, remodelling and reabsorption of ß-TCP on the BMP side. 

Reviewing the current literature, the approach to combine a bone forming osteoconductive element with drug delivery of BMP, is innovative and more efficient than the current application of BMP.

Conclusions:

Ceramic beads combine drug delivery and bone forming elements in a very efficient way. The remodelling process is enhanced and even the reabsorption of ß-TCP stimulated. The application is easy, the bone formation fast and the BMP is safely hold in the chambers of the MCBs.