Temporomandibular Disorders (TMD) usually represent a collection of medical and dental conditions affecting the temporomandibular joint (TMJ) and/or the muscles of mastication, as well as contiguous tissue structures. For some patients with severe TMJ degeneration, a prosthetic replacement may be required. However, long-term success and functioning of current implant designs remains a serious problem due, in large part, to the deterioration of the implant and surrounding tissue resulting from wear debris. In this project, the UAB and Vista Engineering team will develop novel multilayer nanostructured diamond coatings with enhanced adhesion and wear properties for articulation components in TMJ devices. We will also develop commercialization potential through scale-up and TMJ wear testing. UAB and Vista Engineering have a strong track record of collaboration culminating in the licensing (to Vista Engineering) of a UAB patent involving this technology: "Process for Ultra Smooth Diamond Coating on Metals and Uses Thereof", Patent # 6,183,818. Our specific aims are as follows: Specific Aim 1: Develop nanotechnology for reducing friction and wear on the articulating, load-bearing components of TMJ metallic implants (condyle and fossa) by chemical vapor deposition (CVD) of an ultra-smooth diamond coating having a multilayer structure with alternating nano- and micro-structural layered components. Biaxial flexural, indentation, and perimeter loading mechanical tests of the diamond coatings will be performed to determine forces that cause spallation. We will investigate the pin-on-disk wear-resistance of these ultra-smooth coatings (intended for diamond-on-diamond articulation) as compared to single-layer diamond-on-diamond articulation or to the metal-on-polyethylene or metal-on-metal couples currently used in commercial TMJ devices. In parallel to developing diamond coatings, we will utilize a finite element modeling and analysis (FEM/FEA) approach in order to evaluate shapes, sizes, critical dimensions and biodynamic stability of the final TMJ implant designs. Specific Aim 2: Demonstrate the capability for scale-up using the commercial 30 kW CVD reactor at Vista Engineering. We will design and fabricate TMJ implant devices that have a multilayer nanostructured diamond coating for both condyle and fossa components. In this Phase-I grant, the commercially produced TMJ implant will undergo extensive testing in a TMJ simulator to 1.125 million cycles (approximately the equivalent of 10 years clinical use). The successful outcome of this study will be an improved design for TMJ devices and coatings for hard-on-hard articulation. One benefit of the diamond-on-diamond components will be a reduction in overall device size that will ultimately allow for a clinically less-invasive route to joint restoration and longer implant lifetime in vivo. The TMJ device will result in less long-term wear at articulating surfaces. This project will lead to a phase-II application involving particulate reaction by implantation of articulating wear debris into a rat synovial-like air pouch, followed by implantation of the coated TMJ device into a minipig model. PUBLIC HEALTH RELEVANCE: We propose the use of nanotechnology approaches for controlling interfaces between Temporomandibular Joint (TMJ) implants and the surrounding tissues. It is estimated that more than 10 million people suffer from the TMJ-related disorder symptoms in the Unites States alone. The primary focus of this grant application is to improve the fixation, durability and osseointegration for long-term success of TMJ implants and lower the need for recurrent multiple surgical procedures. Also, development of new nanotechnology tools and methods will lead to a new class of functionalized nanostructured surfaces for titanium and cobalt chrome alloys for use in biomedical implant industry. One benefit of the diamond-diamond components will be reductions in overall device size that will ultimately allow for a clinically less-invasive route to joint restoration and longer implant lifetime in vivo. We also propose a clear pathway for commercialization of the nanotechnology enabled TMJ prosthesis.