Study on implanting rat tooth apical and coronal papilla with enamel organ in renal capsule

Objective:To evaluate the inductive effect of rat tooth apical papilla to enamel organ.Method:Tooth apical papilla of mandibular first molar germs of postnatal 7 days SD rat and coronal papilla of second molar combine with the enamel organs of second molar germs of 2 days.The reconstructions were cultured for 2 days and implanted in renal capsules of adult SD rat respectively.After 1,4 weeks the implanted tissues were harvested.The formation of hard tissue and differentiation of dental epithelia were analyzed histologically.Result:after 1 week of transplantation of apical papilla and enamel organ,thin dentin structures could be seen in 4/5 transplants,but the dental epithelia hasn't differentiated and large amount bone like tissue formed.The transplantation of coronal papilla and enamel organ formed tooth crown structure.After 4 weeks there still no enamel formed in the experimental group,and more intact tooth structure developed in control.Conclusion:The apical papilla do not have the ability to induce the differentiation of dental epithelia.