Fast Degradable Calcium Phosphate Cement for Maxillofacial Bone Regeneration

The aim of this preclinical study was to test the applicability of calcium phosphate cement (CPC)-poly(lactic-co-glycolic acid) (PLGA)-carboxymethylcellulose (CMC) as a bone substitute material for guided bone regeneration (GBR) procedures in a clinically relevant mandibular defect model in minipigs. In the study, a predicate device (i.e., BioOss^®) was included for comparison. Critical-sized circular mandibular bone defects were created and filled with either CPC-PLGA-CMC without coverage with a GBR membrane or BioOss covered with a GBR membrane and left to heal for 4 and 12 weeks to obtain temporal insight in material degradation and bone formation. Bone formation increased significantly for both CPC-PLGA-CMC and BioOss with increasing implantation time. Further, no significant differences were found for bone formation at either 4 or 12 weeks between CPC-PLGA-CMC and BioOss. Finally, bone substitute material degradation increased significantly for both CPC-PLGA-CMC and BioOss from 4 to 12 weeks of implantation, showing the highest degradation for CPC-PLGA-CMC (∼85%) compared to BioOss (∼12%). In conclusion, this minipig study showed that CPC-PLGA-CMC can be used as a bone-grafting material and stimulates bone regeneration to a comparable extent as with BioOss particles. Importantly, CPC-PLGA-CMC degrades faster compared to BioOss, is easier to apply into a bone defect, and does not need the use of an additional GBR membrane. Consequently, the data support the further investigation of CPC-PLGA-CMC in human clinical trials. Impact statement Guided bone regeneration (GBR) is a frequently used dental surgical technique to regenerate the alveolar ridge to allow stable implant installation. However, stabilization of the GBR membrane and avoidance of bone graft movement remain a challenge. Consequently, there is need for the development of alternative materials to be used in GBR procedures that are easier to apply and induce predictable bone regeneration. In this minipig study, we focused on the applicability of calcium phosphate cement-poly(lactic-co-glycolic acid)-carboxymethylcellulose as an alternative bone substitute material for GBR procedures without the need of an additional GBR membrane.