Resident, Oral Medicine, Diagnosis, Radiology, and Periodontology, Faculty of Dentistry, Tanta University, Alexandria, Egypt.
Predoctoral student, Biomaterials Laboratory, Faculty of Dentistry, Alexandria University, Alexandria, Egypt.
J Prosthet Dent. 2019 Jan;121(1):118-123. doi: 10.1016/j.prosdent.2018.03.033. Epub 2018 Jun 29.
Reconstruction of alveolar bony defects is difficult using grafting materials in a powder form. A biodegradable scaffold material might simplify the procedure.
The purpose of this in vivo study was to evaluate osteogenesis ability of a biodegradable CAD-CAM-fabricated polylactic acid (PLA) scaffold enriched with calcium phosphate salts including hydroxyapatite (HA) and beta tricalcium phosphate (β-TCP) used to reconstruct mandibular defects in a dog model.
Surgical defects were made bilaterally in the mandible of male beagle dogs. Computerized tomography images were obtained for determination of the 3-dimensional shape of the defects after 3 months of healing. Porous PLA scaffolds were fabricated by milling custom-made CAD-CAM blocks into the desired shape. After milling, half of the scaffolds were prepared by filling the pores of the scaffolds by a mixture of HA and β-TCP. Scaffolds were inserted in the mandibular defects bilaterally. After a healing time of 8 weeks, the bone-scaffold interface was analyzed histomorphometrically to detect the amount of new bone formation. Stained histological sections were examined using a computer software and depth of new bone formation was assessed (n=14, α=.05).
Histomorphometric analysis revealed that enriched scaffolds with calcium phosphates had significantly (t=4.4, P<.001) higher amounts of new bone formation (1.3 ±0.33 mm) compared with the controls (0.7 ±0.39 mm). Average new bone growth in enriched scaffolds was 1.3 mm while almost half this value was observed in uncoated scaffolds, 0.7 mm.
Within the limitations of this animal study, HA and β-TCP enhanced osteogenesis ability of CAD-CAM-fabricated PLA scaffolds.
使用粉末状的移植物材料重建牙槽骨缺损较为困难。一种可生物降解的支架材料可能会使该过程简化。
本体内研究的目的是评估富含钙磷盐（包括羟基磷灰石[HA]和β-磷酸三钙[β-TCP]）的可生物降解 CAD-CAM 制造聚乳酸（PLA）支架的成骨能力，该支架用于重建犬模型下颌骨缺损。
在雄性比格犬的下颌骨双侧制造手术缺损。在愈合 3 个月后，通过计算机断层扫描（CT）图像获取确定缺陷的 3 维形状。通过将定制 CAD-CAM 块铣削成所需形状来制造多孔 PLA 支架。铣削后，通过将 HA 和β-TCP 的混合物填充到支架的孔中来制备一半的支架。将支架插入下颌骨双侧缺损处。愈合 8 周后，通过组织形态计量学分析骨-支架界面来检测新骨形成的量。使用计算机软件检查染色的组织学切片，并评估新骨形成的深度（n=14，α=.05）。
组织形态计量学分析显示，富含钙磷盐的支架具有明显更高的新骨形成量（1.3±0.33mm）（t=4.4，P<.001），与对照组（0.7±0.39mm）相比。富含支架的平均新骨生长为 1.3mm，而未涂层支架的一半值为 0.7mm。
在本动物研究的限制范围内，HA 和β-TCP 增强了 CAD-CAM 制造 PLA 支架的成骨能力。
