摘要目的:探究SD大鼠牙釉质发育期摄入阿莫西林对牙釉质矿化的影响。方法:选取18只新生SD大鼠，采用完全随机的方法将其分为3组，每组6只，对照组和两个实验组大鼠在出生后第3~17天内分别给予蒸馏水、50 mg·kg?1·d?1（50 mg组）和 100 mg·kg?1·d?1（100 mg组）阿莫西林，观察各组大鼠一般状况、肝肾组织结构、下颌第一磨牙及切牙釉质表面情况，X射线能谱仪分析牙釉质表面的Ca/P变化，扫描电镜观察1%磷酸酸蚀后的牙釉质表面形貌变化，HE染色观察大鼠下颌切牙成釉细胞的形态改变。结果:与对照组相比，50和100 mg组大鼠一般状况及肝肾组织结构均未见明显变化。各组大鼠下颌第一磨牙均未见明显的釉面白斑；50和100 mg组所有大鼠上下颌切牙唇面切1/3区均出现不同程度的白垩色改变。X射线能谱仪分析显示，在下颌第一磨牙 1/3区及下颌切牙切1/3区，50和100 mg组的Ca/P（第一磨牙 1/3区分别为1.51±0.03和1.52±0.02，下颌切牙切1/3区分别为1.46±0.01和1.43±0.01）均较对照组（第一磨牙 1/3区为1.67±0.41，下颌切牙切1/3区为1.73±0.07）显著降低（ P<0.05）；在下颌第一磨牙和下颌切牙的颈1/3区，50和100 mg组的Ca/P（第一磨牙颈1/3区分别为1.59±0.05和1.57±0.04，切牙颈1/3区分别为1.47±0.01和1.51±0.03）与对照组（第一磨牙颈1/3区为1.56±0.04，切牙颈1/3区为1.52±0.02）相比差异均无统计学意义（ P>0.05）。扫描电镜观察显示，50和100 mg组下颌第一磨牙和下颌切牙酸蚀处理后釉柱大小不一，排列紊乱，釉柱间隙均较对照组增大，部分区域甚至出现较大的凹坑。HE染色结果显示，50和100 mg组大鼠切牙成熟期成釉细胞细胞间隙较对照组增宽。 结论:SD大鼠牙釉质发育期摄入阿莫西林可能影响其牙釉质矿化。

abstractsObjective:To determine whether amoxicillin had an effect on the enamel mineralization of SD rats.Methods:Eighteen SD rats were randomly divided into three groups. The rats in the control group were given distilled water. The rats in two experimental groups were administered 50 or 100 mg/kg amoxicillin by intragastric administration from day 3 to day 17 after birth. The general condition, the structure of liver and kidney, the enamel surface changes of mandibular first molars and incisors were observed. The changes of Ca/P ratio on enamel surface were analyzed by X-ray energy dispersive spectrometer (EDS). The surface morphology after phosphoric acid treatment was examined by scanning electron microscopy (SEM). Histological changes in the ameloblasts of mandibular incisors were analyzed by hematoxylin and eosin (HE) staining.Results:Compared with the control group, the general conditions as well as liver and kidney structures of SD rats in 50 and 100 mg amoxicillin groups had no significant differences. There was no obvious chalky changes on the first mandibular molars of SD rats in each group. All the incisors in 50 and 100 mg groups showed different degrees of chalkiness in the labial incisal 1/3 enamel. X-ray EDS analysis showed that the Ca/P ratios of occlusal and incisal 1/3 enamel in 50 and 100 mg groups (occlusal 1/3 of mandibular first molars: 1.51±0.03 and 1.52±0.02, incisal 1/3 of mandibular incisors: 1.46±0.01 and 1.43±0.01) was significantly lower than that in the control group (occlusal 1/3 of mandibular first molars: 1.67±0.41, incisal1/3 of mandibular incisors: 1.73±0.07) ( P<0.05). However, there was no significant differences in the cervical 1/3 Ca/P ratio of mandibular first molars and incisors among the three groups (mandibular first molars: 1.56±0.04 for control group, 1.59±0.05 for 50 mg group and 1.57±0.04 for 100 mg group; incisors: 1.52±0.02 for control group, 1.47±0.01 for 50 mg group and 1.51±0.03 for 100 mg group) ( P>0.05). SEM observation showed that the enamel rods of the first molars and incisors in the 50 and 100 mg group varied in size and arranged disorderly. The spaces between the enamel rods were larger than that in the control group and some areas even appeared large pits. HE staining showed that the gaps between ameloblasts in 50 and 100 mg groups were significantly wider than that in the control group. Conclusions:Intake of amoxicillin during the period of enamel development of SD rats might affect enamel mineralization.