CAREER: Aging, Tooth Fracture and the Success of Restorative Dentistry

职业：衰老、牙齿骨折和修复牙科的成功

• 批准号: 0238237
• 负责人: Dwayne Arola
• 金额: $ 31.55万
• 依托单位: University of Maryland Baltimore County
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-06-01 至 2008-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0238237&HistoricalAwards=false
• 关键词: CAREER; Aging; Tooth; Fracture; Success

0238237ArolaDentists generally accept that the revision and replacement of failed restorations consumes the majority of their clinical activities. Tooth fracture is the most detrimental form of failure and often requires complete extraction. The fracture of restored teeth is currently one of the primary obstacles to lifelong oral health. Recent studies reported in the US, UK and Europe indicate that nearly 50% of the teeth in dentate adults aged 45 years and over have been restored. Therefore, in spite of a general decrease in tooth decay among the young, dental restorations will be required and necessitate repair more often over the next ten years. Older people today expect longer, healthier lives and most wish for a functional and aesthetically acceptable dentition over this period.The general hypothesis of the proposed investigation is that restored tooth fractures are fostered by a change in the mechanical properties of dentin with aging. Dentin is a hydrated, mineralized hard tissue that comprises the majority of the tooth by volume. Research activities are aimed at characterizing the mechanical behavior of dentin and correlating its fracture resistance with age utilizing a hybrid approach. Based on preliminary studies, the fracture toughness of dentin is expected to decrease with age of the tissue. To establish the significance of aging on tooth fracture, double cantilever beam specimens will be prepared from the dentin of extracted third molars according to 3 age groups. Monotonic wedge loads will be used to initiate and sustain stable crack growth while the in-plane displacements are monitored as a function of crack length using moire interferometry. Full-field displacements from experiments will be used as the benchmark solution for finite element models of the fracture process. Using an inverse analysis the mechanics of fracture and their contribution to energy dissipation will be obtained precisely from the numerical models. These activities will be complemented with a microscopic analysis of the fracture surfaces to both identify and quantify the influence of aging on the mechanisms of fracture in dentin. The research activities are integrated with an educational plan that extends the impact of a new outreach program for middle school students at the University of Maryland Baltimore County(UMBC). Students who wish to further explore their interests in science will continue as Research Scholars and engage in biomedical research within the PI's laboratory during a 6-week summer program. The educational objectives are to increase participation of underrepresented minorities from Maryland's schools in dentistry and engineering, and promote oral health and science through organized visits from the Research Scholars and their mentors to 7th and 8th grade classrooms in Baltimore's schools. The educational program is supported by a partnership between UMBC, the University of Maryland Dental School and the Meyerhoff Scholars Program. Undergraduate and graduate students in Mechanical Engineering and students from Dentistry will jointly mentor the Research Scholars with their investigations. The Meyerhoff Program will provide professional development activities and introduce the young Scholars to biomedical research in other departments through an undergraduate seminar series.

0238237原始主义者通常接受修订和替换失败的修复体会消耗其大多数临床活动。牙齿断裂是失败的最有害形式，通常需要完全提取。恢复牙齿的断裂目前是口腔健康的主要障碍之一。在美国，英国和欧洲报道的最近的研究表明，在45岁及以上的牙齿成年人中，将近50％的牙齿已经恢复。因此，尽管年轻人的牙齿衰减普遍减少，但仍需要牙齿修复体，并且需要在未来十年内更频繁地修复。当今的老年人期望在此期间期望更长，更健康的寿命和最希望的功能性和美学上可接受的牙列。拟议的研究的一般假设是，牙本质与衰老的机械特性的变化所促进了恢复的牙齿断裂。牙本质是一种水合，矿化的硬组织，包括大部分牙齿的体积。研究活动旨在表征牙本质的机械行为，并使用混合方法将其骨折性与年龄相关联。根据初步研究，牙本质的骨折韧性预计随着组织的年龄而降低。为了确定衰老对牙齿骨折的重要性，根据三个年龄组，将从提取的第三磨牙的牙本中制备双悬臂梁样本。单调楔形载荷将用于启动和维持稳定的裂纹生长，同时使用Moire干涉测量法监测面内位移作为裂纹长度的函数。实验的全场位移将用作断裂过程有限元模型的基准解决方案。使用反向分析，裂缝的力学及其对能量耗散的贡献将准确地从数值模型中获得。这些活性将通过对断裂表面的显微镜分析进行补充，以识别和量化衰老对牙本质骨折机理的影响。研究活动与一项教育计划融合在一起，该计划扩展了马里兰州巴尔的摩县（UMBC）的中学学生的新外展计划的影响。希望进一步探索科学兴趣的学生将继续作为研究学者，并在为期6周的夏季计划中从事PI实验室的生物医学研究。教育目标是增加马里兰州学校从事牙科和工程学的人数不足的少数群体的参与，并通过从研究学者及其导师的有组织的访问来促进口腔健康和科学，到达巴尔的摩学校的7年级和8年级教室。教育计划得到了UMBC，马里兰州牙科学校和梅耶霍夫学者计划之间的合作伙伴关系的支持。机械工程的本科生和研究生和牙科的学生将共同指导研究学者的研究。 Meyerhoff计划将提供专业发展活动，并通过本科研讨会系列将年轻学者介绍给其他部门的生物医学研究。