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

近年来，口腔种植学得到了发展，多种生物材料得到补充并应用于临床。然而，我们对宿主异物识别的基本机制还没有足够的了解。本研究旨在阐明组织和细胞对植入材料(生物材料)的反应，制备与细胞大小相同的颗粒。通过光镜和电子显微镜对皮下注射0.65-30微米的合成羟基磷灰石陶瓷微粒引起的病变进行组织病理学观察。该微粒不溶于水，即为非活性非抗原性异物。实验结果总结如下：实验期间观察到非特异性异物反应。直径在7微米以下的小颗粒被巨噬细胞吞噬，大颗粒或凝结的颗粒被多核巨细胞包围。我们证实了巨噬细胞的成熟过程，提示巨噬细胞融合成异物巨细胞和细胞表面的糖基化在吞噬过程中对异物的识别起重要作用。我们认为即使是生物相容的磷灰石陶瓷颗粒也可以观察到异物肉芽肿的形成。我们希望在牙种植体的长期临床应用中予以关注。

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.