Digital Commons Network^™

A Study Of Aging In Male Cortical Bone Using Nanoindentation, Robert Christopher Singleton

Doctoral Dissertations

The incidence of bone fracture increases with age, due to both declining bone quantity and quality. Towards the goal of an improved understanding of the causes of the age-related decline in the fracture toughness of male cortical bone, nanoindentation experiments were performed on femoral diaphysis specimens from men aged 21-98 years and tibiae from male Fischer F344 rats aged 6, 12, and 24 months (n = 6-11 per age group). Bone is an anisotropic viscoelastic material with a complex hierarchical structure, in which water plays a critical mechanical role by conferring ductility. Because aged bone has been found to have …

Surgical Implant And Tissue Interface, Remigiusz Maciej Grzeskowiak

Doctoral Dissertations

Stability of implant-tissue interface is vital for implant integration with adjacent tissue and it influences directly short- and long-term surgical outcome. The literature provides comprehensive research on implants engaged in soft as well as in hard tissues. Various factors have been found to significantly influence the interface stability. This comprehensive work incorporated several research projects with main focus on implant-tissue interface stability, which was evaluated using biomechanical assessment tools such as pullout, four-point bending as well as reverse torque test. Implants were evaluated under ex vivo conditions, immediately after being placed within tissue as well as under in vivo conditions, …

Novel Osteobiologics For Bone Tissue Engineering, Austin Bow

Doctoral Dissertations

The field of bone tissue engineering features a wide variety of biomaterials designed to facilitate repair and restoration of injured bone tissue. Due to the complex nature of bone, these graft materials face unique challenges in accommodating this highly dynamic environment in which internal structures are being constantly remodeled via osteoblastic and osteoclastic functions. Therefore, effective graft designs must incorporate compositional elements that are capable of promoting and facilitating such activity to permit successful integration with native tissue. These osteobiologic characteristics, including osteo-conduction, osteo-induction, and osseo-integration, are key factors in determining a materials osteogenic capacity and its potential as a …

Variation In Cortical Bone Distribution In The Aging Adult Appendicular Skeleton, Alice Fazlollah Gooding

Doctoral Dissertations

This study considers the effects of age on the distribution of bone in the adult skeleton. Age effects on the skeleton have been studied for diagnosis of osteoporosis or as mechanical compensatory changes to bone shape with loss in density. However, adult skeletal morphology is the result of a lifetime of genetic, dietary, activity, and biochemical factors. With these influences, it unclear at what age(s) bone geometry shifts to adapt to the physiological and mechanical demands placed on it, or, how these adaptations vary within and between bones.

This research addresses these questions by examining skeletal data obtained from the …