The present invention means that a kind of carbonate replaces the bioactivity nanometer particle of non-metering hydroxyapatite, includes a) 40% crystallinity CD below, and the definition of crystallinity is CD=(1-X/Y) 100； Wherein: the height of diffraction peak value when Y=nanometer particle X-ray diffraction pattern 2 θ=33 ° of what, the height of diffraction background when X=2 θ=33 ° of what； B) the width W of the range long L of nm and range nm from 5 to 30 from 20 to 200； And c) the length-width ratio AR between 2 to 40, the definition of the length-width ratio are AR=L/W. ； Bioactivity nanometer particle of the invention preferably uses the various applications of what oral hygiene, can also be configured to used in oral hygiene, for example, solution, suspension, oil, gel or other solid products composition. ； Other aspects of the invention then include a kind of preparation method of oral hygiene suspension containing aforementioned biological activity nanometer particle, a kind of manufacturing method of toothpaste containing the nanometers particle such as this and it is a kind of make tooth and this etc. nanometers asperity contact and allow the method for tooth part demineralization.本發明係指一種碳酸鹽取代非計量羥基磷灰石的生物活性奈米微粒，其具有：a)40%以下的結晶度CD，結晶度的定義為CD=(1-X/Y)‧100；其中：Y=奈米微粒X光繞射圖案於2θ=33°時之繞射峰值的高度，X=於2θ=33°時之繞射背景的高度；b)範圍從20到200 nm的長L及範圍從5到30 nm的寬度W；和c)2到40之間的長寬比AR，該長寬比的定義為AR=L/W。；本發明的生物活性奈米微粒宜用於口腔衛生的各種應用，亦可配製成口腔衛生所用，例如，溶液、懸浮液、油、凝膠或其它固體產品的組合物。；本發明的其它方面則包括一種含有前述生物活性奈米微粒之口腔衛生用懸浮液的製備方法，一種含有該等奈米微粒之牙膏的製造方法，和一種使牙齒與該等奈米微粒接觸而讓牙齒局部脫礦的方法。
