背景:近年來在環境衛生與職業醫學領域的鉛研究報告顯示，鉛暴露對於人體的影響大多是有害的，雖然現在對於鉛的毒性己了解不少，但對於鉛經由懷孕婦女對胎兒在牙齒構造及萌發過程的影響，包含細胞或組織結構上的異常等並無相關研究。
目的:研究鉛暴露對人類胎兒牙齒發育的影響，有其困難度，所以本研究透過實驗動物模式，利用不同的母鼠(outbredstock Wistar rat)分別於懷孕期及哺乳期施以 不同劑量的含鉛離子的飲用水，來了解於懷孕期及哺乳期的鉛暴露對於出生後離乳大白鼠門齒萌發所造成的影響。
方法:本實驗中將懷孕母鼠分為五組，A組為未受任何鉛離子飲用水處置的懷孕母鼠;B組為只在哺乳期進行低劑量的鉛暴露(50ppm)、C組為只在哺乳期進行低劑量的鉛暴露(200ppm); D組為只在懷孕期進行低劑 量的鉛暴露(50ppm)、E組為只在懷孕期進行高劑量的鉛暴露(200ppm)，再測量這五組出生後離乳大白鼠的門齒萌發情形，於出生後60天將出生後離乳大白鼠犧牲，製作切片以光學顯微鏡來觀察。
結果:結果顯示母鼠於哺乳期飲用含鉛離子的飲用水後，不論暴露低劑量或高劑量的鉛皆會使得門齒萌發速率有減緩的情形，哺乳期低劑量組門齒萌發長度為1.44mm(標準差為士0.53mm) ，而高劑量組為1.18mm(土0.23mm)。懷孕期刊ppm與200ppm的出生後離乳大白鼠門齒萌發率皆與對照組無顯著差異，對照組的出生後離乳大白鼠其門齒萌發長度為1.67mm(士0.33mm)，懷孕期鉛暴露50ppm者，萌發長度為1.57mm(土0.65mm);200ppm者，萌發長 度為1.54mm(土0.17mm)。組織型態上可看到哺乳期的暴露組odontoblastslayer厚 度較薄且細胞排列較為鬆散，懷孕期的暴露組則有odontoblastslayer邊緣較為不規 則及不平順的情形出現。
結論:
所以推論幼鼠會對於出生後的鉛暴露感受性較強且對於門齒萌發的影響也較懷孕期來得明顯。

Project background: Lead is a heavy soft metal of dull grayish color， which is usually employed in many industries. According to many research reports， the influence of lead to human body is mostly harmful. Itwas well known that the toxicity of lead could affect children's intelligence quotient， cognition and behavior patterns. There are limited data in Taiwan concerning about the effects of lead through pregnant women to babies and how it would affect newborn baby's tooth structure， eruption rates and enamel formation.
Project objectives: The present study was performed to describe the effects of lead exposure during test animal subject's pregnancy and lactation stages and on the developing teeth of newborn rats. The objective of this study was to investigate the effects of lead exposure during pregnancy and lactation in the tissue and structure of newborn rat's incisors and eruption rates of the incisor.
Materials and methods: This project was performed using laboratory animal models. The laboratory animals used were the outbred stock pregnant Wistar rats. They were exposed to low and high dosage lead (50ppm and 200ppm， respectively) during pregnancy and lactation. Female pregnant Wistar rats were randomly divided into five groups: group A was the control group; group B rats in lactation were fed with low dose of lead (50ppm); group C rats in lactation were fed with high dose of lead (200ppm);group D pregnant rats were fed with low dose of lead (50ppm); group E pregnant rats were fed with high dose of lead (200ppm). The newborn rat's incisor eruption rate was then measured.
Results: Our data showed that the newborn which were exposed to lead during lactation stage had reduced eruption rates of incisors， particularly in high dose.In histological observation， the newborn which were exposed to lead during lactation stage had thiner odontblasts layer; the newborn which were exposed to lead during pregnant stage had irregular odontblasts layer. Conclusion: In conclusion， the data had suggested the newborns exposed to lead during lactation had reduced eruption rate and were more sensitive to lead exposure.