【摘要】 目的:通过对未萌、初萌、成年恒磨牙的咬合面窝沟侧壁釉质剖面显微硬度值的测定,比较三者窝沟侧壁釉质的矿化程度。方法:用激光龋牙探测仪和显微放射照相法选择无龋的未萌牙10个、初萌牙11个、成年牙15个,由窝沟开口至底部,分别测定上、中、下三个部分及颊面釉质的浅层(表面下50μm)和深层(表面下100μm)的显微硬度。结果:成年牙、初萌牙窝沟上部釉质浅层的显微硬度与其窝沟下部有显著性差异(P<0.05),前者明显大于后者;成年牙、初萌牙、未萌牙三者窝沟下部釉质浅层的显微硬度无显著性差异(P>0.05)。成年牙和初萌牙窝沟上部釉质浅层的显微硬度显著大于未萌牙的相应部位(P<0.05)。成年牙、初萌牙和未萌牙窝沟上部釉质深层的显微硬度无显著性差异(P>0.05)。结论:在牙齿萌出后,咬合面窝沟上部釉质表层的显微硬度得到提高,窝沟下部釉质在萌出后无明显变化。更多还原

【Abstract】 AIM:To study the calcification by detecting and comparing the microhardness(MH)of the fissure enamel of the unerupted,young and mature permanent molars.METHODS:Ten unerupted,11 young and 15 mature permanent molars without caries determined by DIAGNOdent and microradiography were enrolled.The fissure was divided into the upper,the middle and the bottom parts.The MH in 50 μm and 100μm layer under the fissure enamel surface of the upper,the middle and the bottom of fissure were examined.RESULTS:The MH in 50μm layer of the upper fissure enamel of young and mature permanent molars was significantly bigger than that of their bottom and the bottom of unerupted permanent molars.There was no difference among The MH of 50μm layer of the bottom enamel of unerupted,young and mature permanent molars.The MH in 50μm layer of the upper fissure enamel of young and mature permanent molars was significantly bigger than that of unerupted permanent molars.There was no difference among the MH of unerupted,young and mature permanent molars in 100μm layer of the buccal and the upper fissure enamel.CONCLUSION:After eruption there is a remineralization in the upper fissure enamel surface of young and mature permanent molars and there is not obvious change in the bottom fissure enamel.更多还原