人牙本质磷蛋白对小型猪修复性牙本质形成作用的实验研究

目的　观察人牙本质磷蛋白 (dentinphosphoprotein ,DPP)对修复性牙本质形成的诱导作用 ,进一步研究DPP的功能。方法　用人DPP粉作盖髓剂 ,对小型猪健康恒牙进行盖髓实验 ,对照组采用氢氧化钙和空白对照 (氧化锌丁香油糊剂盖髓 ) ,通过组织病理学观察牙本质桥的形成。结果DPP盖髓术后 2周 ,穿髓孔下固有牙髓细胞分化为类造牙本质细胞 ,分布在已形成的修复性牙本质团块周围 ;术后 1个月有完整的修复性牙本质桥形成 ;术后 3个月修复性牙本质桥增厚且结构致密 ,主要是管样牙本质 ,其下方排列分化好的造牙本质细胞。氢氧化钙盖髓组 ,术后 2周界面有炎症坏死区 ,只有少量的钙质团块形成 ,1～ 3个月逐渐形成完整的修复性牙本质桥 ,但较DPP盖髓后形成修复性牙本质的速度慢且量较少。结论　人DPP对牙髓刺激性小 ,可以直接诱导牙髓细胞分化及修复性牙本质形成 ,提示DPP在牙本质发育和修复的生物矿化中起重要作用。

Experimental study on the effect of restorative dentin formation with human dentin phosphoprotein in immature permanent teeth of minipig

Objective To investigate the function of human dentin phosphoprotein(DPP) on dentine mineralization in vivo Methods Pulp capping with human DPP was made in the permanent teeth of minipigs with calcium hydroxide and zinc oxide eugenol cement as controls The minipigs were sacrificed at intervals of 14,30,90 days respectively after operation Results The histopathological results revealed that pulp cells had developed into odontoblastoid cells around the major restorative dentin body after two weeks There was complete restorative dentin bridge a month later The bridge became thick and dense, and mainly was tubular dentin in 3 month. There were well developed odontoblasts under the bridge In the calcium hydroxide capping group, inflammatory cytonecrosis zone was found in the surface of dental pulp and only a little calcial bodies formed in two weeks Complete restorative dentin bridge was formed in 1 to 3 months, the speed of dentin bridge formation was not as quick as that of DPP group Conclusion DPP can induce pulp cells to develop into odontoblasts and formation of dentin bridge with little stimulation to the dental pulp This study suggests that DPP plays an important role in the biomineralization of dentin development and restoration