All ETDs from UAB

Advisory Committee Chair

Alan Eberhardt

Advisory Committee Members

Ramzi Abou-Arraj

Jack Lemons

Document Type

Thesis

Date of Award

2017

Degree Name by School

Master of Science in Biomedical Engineering (MSBME) School of Engineering

Abstract

Statement of Purpose: Use of titanium dental implants for treatment of partial or total edentulism has been well documented since the 1980s with consistent long term results. Osseointegration of these implants can be complicated by insufficient bone after healing of extraction sockets or systemic conditions such as osteoporosis or diabetes. Surface modifications, such as grit blasting (mechanical abrasion) or calcium phosphate (CaP) (chemical treatment) can improve healing time and bone quality around an implant. Our study combined a CaP coating with recombinant bone morphogenetic protein-2 (rBMP-2) mimetic peptide and the polyglutamate domain E7. We used nanoindentation to compare the elastic modulus and hardness of newly formed bone between 4 different surface treatments. We hypothesize that our osteoinductive factor will yield a higher modulus and hardness in new bone. Methods: We received 32 slides for nanoindentation testing containing the tibiae of 8 New Zealand White rabbits implanted with threaded titanium dental implants, harvested after a 2 week recovery period. Implant surfaces were coated with CaP and given one of four additional surface modifications: rBMP-2 full-length protein, BMP-2 peptide ± E7, or no treatment (control). Nanoindentation testing was performed with a Nano Indenter® G200 testing system (Keysight, Santa Rosa, CA), following the methods of Oliver and Pharr and Rho and Pharr. Indents were made with a Berkovich diamond indenter tip to a depth of 2500 nm. Drift calculation was performed at 90% unloading. Results: For the immature bone, the E7-BMP-2-pep group had a modulus of 7.848 ± 1.991 GPa and a hardness of 0.321 ± 0.132 GPa, which is significantly higher than the CaP group. The hardness and modulus for E7-BMP-2-pep was higher than BMP-2-pep but lower than the rBMP-2 protein, though the differences did not reach statistical significance (p>0.05). Conclusions: The E7-BMP-2-pep treatment performed comparably to both the BMP-2-pep and rBMP-2 full protein treatments, and outperformed standard CaP. Testing at additional time points can provide more information about rate of bone formation and could highlight differences between treatments.

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Engineering Commons

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