Proteome analysis, renaturation and reutilization of carious dentin

首先，我们研究了现有树脂粘结剂对患龋牙本质的粘接能力。树脂-牙本质粘结剂的粘接强度低于正常牙本质粘结剂，受去龋法的影响较大。然后，我们评估了树脂-牙本质粘接剂界面上纳米渗漏的形成，以确定粘接剂的封闭能力。银粒子作为示踪剂的穿透表明了纳米渗漏的位置，甚至在与正常牙本质的界面上也是如此。不同粘结剂的纳米渗漏表达不同，牙本质的位置也不同。特别是，深腔制备显示出明显的纳米渗漏。我们还利用免疫电子显微镜研究了基质金属蛋白酶(MMPs)在龋齿牙本质(包括细菌感染区和非感染区)以及正常牙本质中的定位。用胶体金标记人龋牙本质冰冻切片，进行定量分析。3个区域间的表达水平差异无统计学意义，内龋区表达降低，外龋区表达增强。唾液中的基质金属蛋白酶-8和基质金属蛋白酶-9可能参与了龋外基质的破坏。此外，我们将粘接到人工脱矿牙表面的树脂粘结剂试件浸泡在磷酸盐缓冲氟化物溶液中，并评估氟吸收对树脂粘结的影响。在氟化物溶液中浸泡后，树脂试件的粘结强度显著提高。为了提高临床操作的可操作性，我们制备了形成羟基磷灰石(HA)的双糊状磷酸钙骨水泥(CPC)。虽然该骨水泥的力学性能不是很好，但我们预计该骨水泥是一种治疗龋病的羟基磷灰石材料。

First, we investigated the bonding capacity of current resin adhesives to caries-affected dentin. The bond strength showed lower values than that of the normal dentin, which were significantly influenced by the caries removal method.Then we evaluated the nanoleakage formation along the resin-dentin adhesive interface in order to determine the sealing ability of the adhesives. The penetration of silver particle as a tracer indicated the location of nanoleakage, even at the interface with normal dentin. Different nanoleakage expressions were revealed among the adhesives used, as well as the location of dentin. Especially, deep cavity preparation revealed distinct nanoleakage.We also investigated the localization of matrix metalloprotainases (MMPs) in carious dentin including bacterial infected zone and non-infected zone, as well as in sound dentin using immunoelectron microscopy. Frozen sections of human dentin with caries were labeled by IgG conjugated with gold colloidal particles, and quantitative analysis was performed. The level of MMP-2 showed no significant difference among the three regions, while MMP-8 and MMP-9 decreased at inner caries, but intensified again at outer caries. MMP-8 and MMP-9 from saliva may participate in matrix breakdown of outer caries. Additionally, we immersed the resin adhesive specimens bonded to artificially demineralized tooth surfaces in phosphate buffered fluoride solution and evaluated the effect of fluoride uptake on the resin bonding. The bond strength of resin specimens was significantly increased after the immersion in the fluoride solution. We prepared dual-paste calcium phosphate cement (CPC) that forms hydroxyapatite (HA) as a final product, in order to improve the handling in clinic. Although the mechanical property of the cement was not so strong, we anticipated the CPC to be HA forming material for caries treatment.