Evaluation of Porous A-tricalcium Phosphate for Maxillary Sinus Augmentation

Objectives: From among the techniques used to regain the height of reduced residual bone, sinus floor augmentation has been a widely accepted method to augment bone volume for implant treatments. From among the bone substitute materials, a-tricalcium phosphate (α-TCP) has a higher biodegradable rate and better integration for physiological bone remodeling than hydroxyapatite. The objective of this study was to evaluate the effects of porous α-TCP as tissue engineered scaffold for maxillary sinus augmentation in a canine model.
Methods: Porous α-TCP were prepared by pulverization of an α-TCP block with 80% continuous pore structures. Sinus floor augmentation surgeries were performed bilaterally in beagle dogs and randomly repaired with the following two groups: the experimental group consisted of porous α-TCP and titanium (Ti) implant; the control group consisted of Ti implant alone. Bone mineral content (BMC) and new bone formation around the implants were measured and analyzed using micro-CT imaging and Villanueva goldner staining for histological examination, respectively. The differences between the experimental group and the control group were evaluated by student t-test.
Results: Micro-CT images at 4, 8, and 12 weeks after surgery showed higher BMC in the experimental group than in the control group (p<0.05). Histological images showed the presence of many porous α-TCP even at 4 weeks; however, the scaffolds were completely absorbed and new bones integrated to the Ti implants at 8 and 12 weeks. On the other hand, no bone formation was observed in the control group during the entire duration of the study.
Conclusions: In conclusion, porous α-TCP promoted mineralization, volume and earlier bone formation of augmented maxillary sinus. Therefore, this tissue engineered scaffold might be a better alternative to autologous bone for the clinical edentulous maxillary sinus augmentation.