研究背景:鉛金屬進入人體後會儲存於硬組織，如牙齒。美國的流行病學研究指出，非裔美國人及低收入低教育的居民，在環境中有高劑量的鉛暴露導致高輔齒率的情形，因此懷疑鉛暴露對於攝齒率的上升有正向影響。現今對鉛暴露影響的研究，多針對神經系統及兒童發育，在牙齒發育構造及致騙性的研究極為少見。
研究目的:本研究以動物實驗模式，探討針對實驗用雌性大白鼠懷孕期及哺乳期分別進行飲用水的鉛暴露，其出生後離乳大白鼠的臼齒發育及輔齒率是否有影響。
研究方法:本研究共有4組實驗組和l組對照組，對照組飲用Ro水，實驗組分別於懷孕期及哺乳期飲用不同劑量 的合鉛飲水(低劑量組:50 ppm;高劑量組200 ppm) ，幼鼠斷奶後，對照分1、2兩組，給予對照2組及實驗組高含糖飼料(60%果糖)，30天後犧牲取其下顆骨， 以立體顯微鏡觀察臼齒輔齒情形，以切片觀察臼齒組織變化。
研究結果:攝齒病仕數方面，實驗組多於對照組，但實驗組之間沒有差異。輔齒指數則可以發現，實驗組的指數較對照組高，懷孕期高劑量組10.83分(標準差±2.56)較低劑量組8.83分(±1.94)高，哺乳期高劑量組的7.67分(±1.63)與低劑量組7.83分(±0.7日之間無差異，懷孕期暴露組的輔 齒指數有比哺乳期暴露組高的趨勢。切片方面可以觀察到不透明的白色條紋，以及鈣化程度不一致，使得染色深淺不一的情形。
結論:實驗動物模式可以較精確的控制鉛暴露時期，因此可以判斷懷孕期暴露組的攝齒指數有比哺乳期暴露組高的趨勢;而懷孕期暴露組別中，高劑量組的攝齒指數高於低劑量組。

Project background: Due to the presence of lead in the air or food source， the human bodies would somehow have traceable amount of lead inside them that might affect people's health considerably. A relative literature had suggested that there was an inverse relation between the density of lead inside teeth and intelligence quotient of the infants.
Project objectives: The objective of present study were to evaluate the effects of lead exposure during pregnancy and lactation stage in the tissue and structure of newborn rats' molar teeth， and to investigate the carious rates of molar teeth. This study was performed using animal models. Materials and methods: The laboratory animals used were albino rats of Wi star strain that were fed with lead in drinking water during their pregnancy and lactation stage. Fifteen pregnant Wistar rats were randomly divided into five groups with three rats in each group: group I pregnant rats were fed with low dose of lead (50ppm); group 2 pregnant rats were fed with high dose of lead (200ppm); group 3 rats in lactation were fed with low dose of lead (50ppm); group 4 rats in lactation were fed with high dose of lead (200ppm); group 5 was the control group. The infant rats were provided with a cariogenic diet containing 60% fructose for four weeks that begun from the 30th day after birth. At the end of experimental period， the rats were sacrificed， their mandible molar tooth removed and hemisectioned to measure the caries lesions and grades for caries index.
Results: Our data showed that lead-exposure experimental groups had higher caries lesions than control group and there was no significant difference among the four lead-exposure experimental groups. The lead-exposure experimental groups also had higher caries index than the control group. In addition， the groups that were fed with high dosage of lead had higher caries index than the low dosage group. The pregnant groups had higher caries index than the lactation groups. The caries index of pregnant groups with high dosage lead was significantly higher than the control group.
Conclusion: The pregnant groups had higher caries index than the lactation groups. The caries index of pregnant groups with high dosage lead was significantly higher than the control group. With animal models， the dosage exposure and exposure periods can be artificially controlled.