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Bioinspired Composites for Dental Restorations

用于牙齿修复的仿生复合材料

基本信息

批准号：
9004620
负责人：
ISABEL K LLOYD
金额：
$ 18.4万
依托单位：
UNIV OF MARYLAND, COLLEGE PARK
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-03-01 至 2018-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9004620
关键词：
Affect Anisotropy Anterior Anti-Bacterial Agents Bacteria Behavior Biomimetics Bite Characteristics Chemistry Clinical Collagen Complex Composite Resins Dental Dental Enamel Dental caries Dentin Development Disease Engineering Environment Esthetics Evaluation Failure Filler Fracture Future Generations Goals Grant Growth Health Hydroxyapatites In Situ Knowledge Lead Length Ligands Literature Mastication Mechanics Nanosphere Oral Oral cavity Outcome Penetration Performance Plant Resins Polymers Process Property Recurrence Residual state Resistance Science Shapes Silicon Dioxide Siloxanes Solvents Streptococcus mutans Stress Structure Surface Swelling System Techniques Thermodynamics Titania Titanium Tooth structure Viscosity Work base composite restoration covalent bond density design functional group improved innovation inorganic phosphate interfacial liquid crystal mechanical behavior monomer nanorod novel particle polymerization polymerization shrinkage posterior restoration programs response restoration restorative dentistry retinal rods self assembly self organization

项目摘要

DESCRIPTION (provided by applicant): Commercial resin composites work well in anterior restorations. However, in posterior restorations the clinical failure rate is 25% or more after 10 years with fracture being one of the two key contributors to failure. This program seeks to improve the clinical performance of resin based posterior restorations by developing a new class of dental composites that mimic the microstructure and mechanical behavior of enamel. We hypothesize that mimicking enamel near the dentin-enamel junction (DEJ) can increase the lifetime by enhancing resistance to crack formation and growth as well as subsequent material loss or bacterial penetration and recurrent decay. In particular, we hypothesize that imitating the enamel columns and the disoriented crossed rods between them can increase toughness while enhancing strength relative to the biting surface. Further, we believe that including stiffer fille materials like titania can enhance load transfer to the remaining tooth which would reduce fracture [and formation of marginal gaps] by decreasing the stress carried by the composite. [In addition, we will seek to minimize marginal gap formation by 'tuning' filler and matrix composition to better match the coefficient of thermal expansion of the tooth.] Our program is novel in its approach to mimicking enamel structure and in the type of composites we propose to develop. Unlike previous attempts to mimic enamel structure that focused on the controlled growth of hydroxyapatite crystals outside the mouth, we propose a system that develops its structure in-situ. Further, unlike commercial composites that have dispersed non-organized filler particles we propose an entirely new class of composites with hierarchically organized filler particles. Our approach will involve synthesizing and functionalizing silica and titania nanorods in low shrinkage phosphate or siloxane based acrylic liquid crystal monomers. These nanorods will be organized into bundles that imitate enamel prisms and then self-assembled into larger ordered structures together with additional discrete filler rods and particles in monomers that wil be subsequently solidified during polymerization. The organization of rods into bundles and then into larger structures will be controlled by thermodynamics and interfacial chemistry through the functionalization process and shape anisotropy. We will [iteratively design the composite microstructure and composition and] validate the potential of the composites as future restoration materials, by systematically assessing the polymerization shrinkage, swelling in a simulated oral environment and mechanical properties including flexural strength, elastic modulus, storage and loss modulus, and toughness. [In addition, we will evaluate the interactions of S mutans, the bacteria typyically responsible for secondary caries to determine if the composites have anti-bacterial properties of if the bacteria degrades the composite.] Because the approach is so new, we are requesting an exploratory grant to develop the enabling techniques required for this new class of highly filled (~60 vol%) composites. Our objective is to demonstrate the feasibility of our approach from a fundamental science, engineering and dental perspective.