Biological Materials Science: Biological Materials Science VI
Sponsored by: TMS Functional Materials Division, TMS: Biomaterials Committee
Program Organizers: David Restrepo, University of Texas at San Antonio; Steven Naleway, University of Utah; Jing Du, Pennsylvania State University; Ning Zhang, Baylor University; Hannes Schniepp, William & Mary
Wednesday 4:00 PM
March 2, 2022
Room: 201B
Location: Anaheim Convention Center
Session Chair: Jeffrey Bates, The University of Utah
4:00 PM
Micromechanical and Microstructural Studies of Wavy Enamel in the Grinding Dentition of Hadrosaurid Dinosaurs: Understanding Its Remarkable Damage Tolerance and Fracture Resistance: Soumya Varma1; Yi Lee2; Shane Johnson3; D. G. Harlow4; Tomas Grejtak5; Brandon Krick5; Tyler Hunt5; Gregory Erickson5; Manish Jain6; Johann Schwiedrzik6; Johann Mitchler6; Daniele Casari6; Sandip Basu7; Shraddha Vachani1; Sid Pathak1; Arun Devraj8; 1Iowa State University; 2Exxon Mobile; 3University of Nevada Reno; 4Lehigh University; 5Florida State University; 6EMPA; 7Bruker Nano Surfaces; 8Pacific Northwest National Laboratory
This research aims to understand the structure-property relationship of crenulated wavy enamel (CWE) found in herbivorous hadrosaurid dinosaurs. Preliminary analysis of the tissue showed an undulating wavy structure composed of folded layers of hydroxyapatite crystallites separated by thin layers of a loosely aggregated interlayer matrix. CWE exhibits remarkable fracture resistance, damage localization, and controlled crack directionality, how this bi-partite enamel composite achieves this remained unknown. To investigate these properties, we utilized optical profilometry, BSE-SEM, and APT for microstructural analysis. We correlated this information with spherical nanoindentation and micropillar compression experiments quantifying elastic (Modulus) and plastic (Yield Strength, Fracture Stress) properties at individual layers (few µm3 volumes) and at the global CWE ensemble level (10s of µm3 volumes). Interestingly, the elastic mismatch between layers in combination with the kinking of layers, enhances damage tolerance exclusively in the transverse/occlusal plane, promoting integrity of the enamel crest.
4:20 PM
Dynamic Finite Element Analysis of QPD Crack Detection in Natural Teeth: Jie Shen1; Omid Komari1; Aboozar Mapar2; Cherilyn Sheets3; James Earthman1; 1University Of California Irvine; 2Perimetrics, Inc.; 3Newport Coast Oral Facial Institute
Quantitative percussion diagnostics (QPD) has been used to detect cracks in teeth. The goal of the present research is to use finite element analysis (FEA) to understand the complexity and patterns of force-time plots by QPD with cracked teeth. Multiple FEA models of a scanned, converted, and meshed tooth geometries were developed including intact, short, and long vertical cracks. A QPD percussion rod was included in all models so that the force measured by a sensor in this rod could also be simulated. Both short and long vertical crack models correctly exhibit multiple peaks in percussion force-time plots. Further, deeper valleys between the peaks were predicted with increasing crack length. Comparison of relative velocities of the crack surfaces with the percussion force as a function of time indicates that the additional force peaks are due to crack face oscillations.
4:40 PM
Enhancing Biocompatibility of Zinc Nanocomposites with Improved Nanoparticle Incorporation: Jingke Liu1; Chase Linsley1; Yuxin Zeng1; Benjamin Wu1; Xiaochun Li1; 1University of California Los Angeles
Recently, nanoparticle-enhanced zinc alloys (zinc nanocomposites) have drawn tremendous interest as a favorable biodegradable metal for implants due to its good biodegradability, stable mechanical integrity during degradation, and promising biocompatibility. Molten-salt-assisted incorporation of nanoparticles is successfully applied to incorporate nanoparticles into molten zinc. However, the processing process is complicated and can lead to complications in its cytocompatibility, especially when foreign salt contamination is accidentally introduced into the zinc alloys. This study introduces an improved processing method for the biodegradable zinc nanocomposites to minimize the contamination of molten salt into molten zinc. The newly processed zinc nanocomposites offer enhanced cytocompatibility without impacting other favorable bioimplant properties.