Study of Tetracalcium Phosphate-Citric Acid Complex Cement : a New Direct Pulp-Capping Agent

新型直接盖髓剂磷酸四钙-柠檬酸复合水泥的研究

• 批准号: 05557093
• 负责人: SOBUE Sizuo
• 金额: $ 7.3万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research (B)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05557093/
• 关键词: Tetracalcium phosphate; Citric acid; Direct pulp capping; Reparative dentin

Tetracalcium phosphate-citric acid complex cement (4CPC) has been shown to convert to hydroxyapatite in phosphate buffered saline and possess some excellent physical and chemical properties as a biocompatible cement. The purpose of this study was to evaluate the possibility of the application of 4CPC as a direct pulp capping agent.The cytotoxicity of 4CPC was assessed by the chromium-51 release cytotoxicity test. The histopathological and crystallographic examinations of 4CPC were made in permanent dog teeth. Thirty eight mongrel dogs were used. A class V cavity was prepared on the buccal surface of canines, premolars and molars. After a pin spot of pulp exposure was affected by sterile explorer, 4CPC was carefully placed on the exposure site. The contralateral tooth was used as a control and calcium hydroxide (Dycal^<(R)>, L.D.Caulk) was applied. After 3 days, 1,2,4,8 weeks, 6 months and 1 year, the dogs were perfused with 10% or 4% neutral formalin. The response of dental pulp to 4CPC,the process of reparative dentin formation and the relation between 4CPC and reparative dentin formation were investigated when the cement was placed directly on the dental pulp of dogs. The results were as follows ;1.4CPC was a non-cytotoxic material.2. No necrotic layr was found beneath 4CPC3. Reparative dentin was formed in the teeth capped with 4CPC earlier and more frequently than in those capped with Dycal^<(R)>.4. Reparative dentin was formed within 50% of the 4CPC mass, while no reparative dentin was formed within the Dycal^<(R)> mass.5. In the teeth capped with 4CPC,reparative dentin was formed after the increase of alkaline phosphatase activities in pulp cells, and the synthesis of primary dentin-like collagen and proteoglycans. All of these findings seemed to be in connection with 4CPC.6.4CPC intrinsically converts to hydroxyapatite.These findings suggest that 4CPC is biodegradable and a favorable material as a direct pulplining cement.

磷酸四钙-柠檬酸复合骨水泥(4CPC)在磷酸盐缓冲溶液中可转化为羟基磷灰石，具有良好的生物相容性。本研究的目的是评价4CPC作为直接盖髓剂的可能性，通过铬-51释放细胞毒性试验评价4CPC的细胞毒性。对4CPC恒牙进行了组织病理学和结晶学检查。共使用了38只杂种狗。在尖牙、前磨牙和磨牙的颊表面制作V类洞。在无菌探针器作用于牙髓外露的针点后，将4CPC小心放置在外露部位。以对侧牙为对照，应用氢氧化钙(Dycal^&lt；(R)&GT；，L.D.Caulk)。分别于术后3天、1周、2周、4周、8周、6个月、1年分别灌胃10%或4%中性福尔马林。将粘固剂直接放置于犬牙髓上，观察牙髓对4CPC的反应、修复性牙本质的形成过程以及4CPC与修复性牙本质形成的关系。结果表明：1.4CPC是一种非细胞毒性材料。4CPC3下未见坏死层。修复性牙本质的形成早于Dycal和Dycal；修复性牙本质在4CPC团块的50%范围内形成，而在Dycal^lt；(R)；4CPC盖髓后，牙髓细胞碱性磷酸酶活性增强，初级牙本质类胶原蛋白和蛋白多糖合成，形成修复性牙本质。所有这些发现似乎都与4CP有关。6.4CPC本质上会转化为羟基磷灰石。这些发现表明，4CPC是可生物降解的，是一种良好的直接制浆水泥材料。