Amorphous calcium phosphate based dental materials

无定形磷酸钙基牙科材料

• 批准号: 7567522
• 负责人: DRAGO SKRTIC
• 金额: $ 36.38万
• 依托单位: AMERICAN DENTAL ASSOCIATION FOUNDATION
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-03-01 至 2012-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7567522
• 关键词: Adhesions; Adhesiveness; Adhesives; Adverse effects; Apatites; Apoptotic; Biocompatible; Biological; Cell Survival; Cells; Characteristics; Chemical Structure; Chemicals; Clinical; Complex; Dental; Dental Clinics; Dental Materials; Dental crowns; Dentin; Diffusion; Drug Formulations; Endodontics; Ensure; Evaluation; Exhibits; Extravasation; Filler; Goals; Grant; Human; In Vitro; Inflammation; Interphase; Lead; Learning; Mechanics; Membrane; Minerals; Modeling; Modification; Movement; Natural regeneration; Necrosis; Oral; Orthodontic; Performance; Pit and Fissure Sealants; Plant Resins; Polymers; Process; Property; Pulp Canals; Reaction; Research; Resistance; Root Caries; Stress; Structure; Study models; System; Technology; Testing; Time; Tooth Demineralization; Tooth structure; Toxic effect; Urethane; Water; base; biomaterial compatibility; calcium phosphate; canals sealer; copolymer; cytotoxicity; cytotoxicity test; demineralization; design; monomer; polymerization; polymerization shrinkage; prototype; public health relevance; remineralization; research clinical testing; response

DESCRIPTION (provided by applicant): Our studies of amorphous calcium phosphate (ACP)-based dental materials (grant DE13169; initiated in the year 2000) were aimed to develop experimental bases/liners and orthodontic cements with moderate mechanical strength, good adhesiveness to tooth structures and pronounced potential to protect teeth from demineralization or even regenerate lost tooth mineral. Recently, a pit and fissure sealant, a crown and bridge cement and a light-cure orthodontic adhesive, all based on ACP/polymer technology developed in our group, have been made commercially available to dental practitioners. This continuing proposal focuses on design and evaluation of ACP composite materials intended for endodontic utility. The expected favorable biocompatibility of such composites is anticipated because of the design of resin systems with a high degree of conversion on polymerization (resulting in minimal leachables of organic species) and the chemical similarity of ACP to biological mineral. The bioactivity of the latter is due to the propensity of ACP to convert to thermodynamically stable apatite once exposed to oral milieu. The biocompatibility of the proposed new materials should be equal to, if not exceeding, the biocompatibility of currently utilized endodontic materials with the added benefit of ACP's long-lasting anti-cariogenic power. The main objectives are: [1] to assess the feasibility of formulating flowable, low-shrinking ACP composites with minimized leakage of unreacted monomers and/or degradation products and [2] to evaluate in vitro diffusion of material extracts through dentin barrier and assess their cytotoxicity. To achieve these goals we propose to: (a) formulate chemical cure and/or dual-cure resin capable of attaining high levels of vinyl conversion with the minimal adverse effect on shrinkage and/or stress developed upon polymerization, (b) create composites based on such resins with finely-dispersed ACP fillers, (c) evaluate physico-chemically both the unfilled resins (copolymers) and composites, (d) determine the movement of extracts of set materials across a dentin barrier, and (e) assess cellular response to copolymers and composites. The completion of the proposed research is expected to provide model material(s) suitable for endodontic clinical evaluation. In addition to the clinical impact, the studies may offer new experimental evidence still needed to better understand the polymer/filler and composite/tooth interphase phenomena as well as the cellular responses to these types of dental materials. Public Health Relevance: The proposed research on amorphous calcium phosphate (ACP)-based dental materials will: a)contribute to the basic understanding of the complex structure/property relationships in bioactive, remineralizing dental polymeric materials, and b) provide a model for the study of the demineralization/remineralization processes. An applicative aspect of this study is the design of an ACP endodontic sealer that would be both bioactive and biocompatible. Additionally, this technology may also lead to a bondable, remineralizing material that adheres to tooth structures and could mitigate root caries.

描述（由申请人提供）：我们对无定形磷酸钙（ACP）基牙科材料的研究（批准DE13169； 2000年启动）旨在开发具有中等机械强度、良好的牙齿结构粘附性和明显的保护牙齿不脱矿甚至再生牙齿矿物质潜力的实验基托/衬垫和正畸水泥。最近，基于ACP/聚合物技术的牙槽和牙槽密封剂、牙冠和牙桥水泥以及光固化正畸胶粘剂，都已经被商业化提供给牙科医生。这篇持续的提案集中在设计和评估用于牙髓治疗的ACP复合材料。预期这种复合材料具有良好的生物相容性，因为树脂体系的设计具有高度的聚合转化（导致有机物质的可浸出性最小），并且ACP与生物矿物的化学相似性。后者的生物活性是由于ACP一旦暴露于口腔环境就会转化为热力学稳定的磷灰石。所提出的新材料的生物相容性应等于（如果不超过）目前使用的牙髓材料的生物相容性，并具有ACP持久抗龋齿能力的额外好处。主要目标是：[1]评估配制可流动、低收缩的ACP复合材料的可行性，最大限度地减少未反应单体和/或降解产物的泄漏；[2]评估材料提取物通过牙本质屏障的体外扩散并评估其细胞毒性。为实现这些目标，我们建议：(a)配制化学固化和/或双固化树脂，能够实现高水平的乙烯基转化，同时对聚合产生的收缩和/或应力产生最小的不利影响；(b)使用精细分散的ACP填料制造基于这些树脂的复合材料；(c)对未填充的树脂（共聚物）和复合材料进行物理化学评估；(d)确定固定材料提取物穿过牙本质屏障的运动。(e)评估细胞对共聚物和复合材料的反应。该研究的完成有望提供适合牙髓临床评估的模型材料。除了临床影响外，该研究还可能提供新的实验证据，以更好地了解聚合物/填料和复合材料/牙间期现象以及细胞对这些类型的牙科材料的反应。