有效应对各种骨缺损，确保钛种植体周围有足够骨组织，是口腔种植亟需解决的问题。骨组织工程是具有应用前景的处理方法。能否通过细胞膜片骨组织工程在钛种植体表面获得类似自体骨的成骨效果？课题组在前期工作中证实，成骨细胞膜片具有较强的体外成骨能力。本研究拟对钛种植体表面的BMSCs细胞膜片施加不同浓度和时间的EMD，通过细胞化学、RT-PCR、 Western Blot等，观测EMD对其成骨性的影响；加入Wnt拮抗剂DKK1，对比β-catenin、OPG、RANKL等表达变化，分析EMD是否通过Wnt信号通路影响钛种植体表面BMSCs细胞膜片的成骨效应 ，探讨其调控机制。构建骨缺损动物模型，采用EMD与BMSCs细胞膜片等进行骨再生处理，通过硬组织切片、Micro-CT等方法，观察其对钛种植体周围骨缺损的修复能力，探讨EMD/BMSCs细胞膜片骨组织工程在钛种植体表面骨再生的效应。

Effective solutions to complex bone defects that ensure adequate healthy bone tissue around the titanium implant are urgently needed in dental implant treatment. Bone tissue engineering represents an alternative method with prospects for application in the clinic.However, it remains unclear whether bone tissue engineering with cell sheets can achieve an osteogenic effect on the titanium implant surface similar to autologous bone. Our previous study demonstrated that osteoblast cell sheets showed a strong osteogenic capability in vitro. The current study will apply enamel matrix derivative (EMD) at different concentrations and reaction times to bone marrow stromal cells (BMSCs) sheets on the titanium implant surface and assess the effect of EMD on the osteogenesis of BMSCs sheets by morphology, cytochemistry, RT-PCR, and Western blotting. The expression levels of β-catenin, osteoprotegerin (OPG), and receptor activator of nuclear factor-kappa B ligand (RANKL) will be compared before and after treatment with the Wnt antagonist DKK1, to analyze whether EMD affects the osteogenesis of BMSCs sheets on the titanium implant surface through the canonical Wnt signaling pathway and to explore its regulatory mechanism. An animal model of bone defects around titanium implants (e.g., the one wall and two walls bone defect) will be established, and the bone regeneration process was evaluated for bone defect treated with EMD and BMSC sheets. hard tissue sections and micro computed tomography (micro-CT) will be performed to observe the ability of EMD/BMSC sheets to repair bone defects around the titanium implants and to investigate the effect of bone tissue engineering with EMD/BMSC sheets on bone regeneration on the titanium implant surface.