Patholory of dental implants A cellular pathological study of responses to non-antigenic foreign body

近年来，口腔种植学得到了长足的发展，多种生物材料得到了广泛的应用。然而，我们对宿主的异物识别的基本机制还没有足够的认识。本研究旨在阐明组织和细胞对植入材料（生物材料）的反应，制备的颗粒大小与细胞大小相同。采用光镜和电镜对皮下注射合成羟基磷灰石陶瓷微粒（0.65 ~ 30 μ m）致病变的时间过程进行组织病理学观察。这种微粒不溶于水，换句话说，是一种无活性、无抗原的异物。结果总结为；实验期间观察非特异性异物反应。直径小于7微米的小颗粒被巨噬细胞吞噬，大颗粒或凝固的颗粒被多核巨细胞包围。我们论证了巨噬细胞的成熟过程，认为巨噬细胞融合到异物巨细胞和细胞表面的糖萼在吞噬过程中对异物的识别起着重要作用。我们得出结论，即使是生物相容性的磷灰石陶瓷颗粒也能形成异物肉芽肿。我们建议注意种植牙的长期临床应用。

Recently, dental implantology has been developed and many kind of biomaterials were supllied and used in clinically. However, we did not have sufficient knowlege for the fundamental mechanism of host's foreign body recognition.This study was planned to clarify tissue and cell responses to implant materials ( biomaterial ), the particle size was prepared as large as cell size.Time course histopathological observation of lesions induced by subcutaneous injections of fine ceramic particles of synthetic hydroxyapatite, ranging 0.65 - 30 microns,was performed by light and electron microscopy. This particle is not soluble in water, in other word, inactive and non-antigenic foreign body.The summary of the result is; non-specific foreigh body reaction was observed through the period of experiment. The smaller-sized particles, under 7microns indiameter, were phagocytized by macrophages and larger-sized or coagulated particles were surrounded by multinucleated giant cells. We demonstrated the maturation course of macrophage and suggested that macrophages fused into foreign body giant cells and glycocalyx of cell surface play an important role in the recognition of foreign body in the process of phagocytosis.We concluded that foreign body granuloma formation was observed even biocompatible apatite ceramic particles. We abvise to take notice about in long-term clinical applications of dental implants.