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ADA Foundation, the American Dental Association, Colgate-Palmolive Company Announce Commitment to Support Dr. Anthony Volpe Research Center

The ADA Foundation (ADAF), the ADA, and the Colgate-Palmolive Company have announced a joint initiative to enhance the ADA Foundation’s existing dental research laboratory in Gaithersburg, Md., and to support and encourage promising young researchers. Read more.

The American Dental Association Foundation's (ADAF) dental research enterprise at the Dr. Anthony Volpe Research Center (formerly known as the Paffenbarger Research Center) has been hailed as one of the most productive in the world. ADA and ADAF research scientists have engaged in cooperative dental and medical materials research with government scientists since 1928. This collaboration at the National Institute of Standards and Technology (NIST, formerly NBS, the National Bureau of Standards, a government research laboratory managed by the U.S. Department of Commerce) has in many respects revolutionized the practice of dentistry. 

Projects

The Dr. Anthony Volpe Research Center is active in cutting-edge fields of biomaterial and tissue engineering technologies that are unique to our institute. That emphasis is by design, as both our support and our facilities allow us to pursue high-risk technologies that few others can. We also emphasize a strong applied research program by working closely with industry to translate new technologies into clinical and over-the-counter products. Our projects target technologies that meet the needs of patients, but also fit within the oral care delivery system and the industries that serve it.

Biomaterials/Biomineralization

Clinical Science/Therapies

Standard-related Activities

Scientific Collaboration/Education 

Biomaterials/Biomineralization

Airbrushed, Polymeric Nano-fiber Scaffolds for Bone Tissue Regeneration

Non-woven polymeric nano-fiber scaffolds are of particular interest to tissue engineering (TE) since the fibrous mats emulate the structure of native extracellular matrix.  However, nano-fiber scaffolds are typically synthesized using an electro-spinning method which is slow and requires high voltage equipment. Dr. Wojtek Tutak is currently developing an alternative to electro-spinning. He is using airbrushing, a technique that forms fibers when compressed gas is mixed with a polymer solution and forced through a small nozzle. Significantly, this technology can be applied to a wide spectrum of polymers and used for rapid in-situ and ex-situ nano-fiber scaffold fabrication. It offers higher deposition rates, safer operation and approximately 100-fold lower cost compared to electro-spinning. The resulting scaffolds support the in vitro primary human bone marrow stromal cell growth and osteogenic differentiation. This inexpensive, safe, high-throughput approach has potential for applications in regeneration of periodontal bone defects, design of implants with promoted scaffold vascularization and sustained bone formation. This project also seeks to improve the fundamental understanding of in-vitro bone formation and develop more reliable material evaluation methods and TE standards.
For further information, please contact Dr. Wojtek Tutak at: wojtek.tutak@nist.gov.

Bioactive ACP Composites

Polymeric materials containing amorphous calcium phosphate (ACP) arrest tooth demineralization and even regenerate defective tooth structures via 1) mineral ion release and 2) the subsequent deposition of these ions as apatite, a natural inorganic constituent of enamel and dentin.  Dr. Anthony Volpe Research Center researchers have systematically investigated structure-composition-property relationships in ACP/methacrylate composites for almost two decades.  The ultimate goal of these studies is to design bioactive remineralizing materials that adhere well to both enamel and dentin. Besides practical applications (formulation of the remineralizing ACP sealant, orthodontic adhesive and endodontic composite), our studies also contribute to a better understanding of the physico-chemical and mechanical properties of these polymeric ACP composites, ACP composite/tooth interfacial phenomena and cellular responses to these materials. Generally excellent biocompatibility, possible osteoinductivity, and affinity for proteins and cells make ACP potentially attractive for tissue engineering applications.  Exploratory studies of ACP-loaded bioresorbable polymers intended for general bone regeneration are currently in progress. In addition, a feasibility of incorporating new quaternary ammonium methacrylates with adhesive and coupling functions into polymer phase of ACP composites to design restoratives with both antimicrobial and remineralizing ability is being explored.
For further information, please contact Dr. Drago Skrtic at drago.skrtic@nist.gov.

Bioactive Nano Materials

Nano forms of hydroxyapatite and other bioactive materials are prepared by a novel method developed under a new NIH grant, employing a spray drying technique in such a way that (1) target particle sizes over a wide range can be obtained, (2) compounds with either low or high solubility can be prepared, and (3) the prepared particles would not be exposed to any solution environment after their formation and therefore would retain their original, highly reactive surfaces. Due to their small sizes and high reactivity, the prepared nano-materials are expected to have a range of clinical applications. Ongoing studies evaluate the effectiveness of nano-sized calcium fluoride as the source of fluoride for remineralizing enamel carious lesions, and the effectiveness of nano-sized calcium phosphates and calcium fluoride in reducing dentin permeability.
For further information, please contact Dr. Larry Chow at larry.chow@nist.gov.

Calcuim Phosphate Bone Cements

Calcium phosphate bone cement based on ADAF patents was introduced to the market in November 1997 under the trade name BoneSource®. The product has thus far received FDA approval for craniofacial and maxillofacial applications. This plaster-like material can be placed surgically, molded and sculpted to the correct anatomical shape, and will set to form a hard implant composed entirely of hydroxyapatite. The implant material is slowly dissolved and replaced entirely by new bone, thus repairing the original defect. Additional studies have led to significant improvements in the handling properties of the cement and development of cement formulations that would be suited for different clinical applications.
For further information, please contact Dr. Larry Chow at larry.chow@nist.gov.

Dental Resin-composite Restorations Containing TiO2 Nano-particles

This project is aimed to develop novel resin-composite restorations with improved durability and sustained broad-spectrum antimicrobial properties, thereby increasing the clinical longevity of the polymeric restorations. The overall purpose of the study is expected to be achieved by combining the advanced nano-technology and material design. Specific objectives are to: 1) maximize the functions of TiO2 nano-particles (NPs) as initiators and accelerators for photo-polymerization of dental resins, 2)  maximize the photo-catalytic activities of TiO2 NPs in dental resins through their surface functionalization,  3) formulate and evaluate TiO2-containing dental adhesives. The successful completion of the proposed research is expected to produce novel, strong and durable dental restorations that could also fight against bacterial attack. Additional benefits are predicted cost savings for the general public due to a significant reduction in the number of restoration replacements.
For further information, please contact Dr. Jirun Sun at: jirun.sun@nist.gov.

Engineering Nano-medicine

Nano-medicine applies nano-science and technology to monitor, repair, and control the human biological systems by using materials and structures engineered at the atomic or molecular level. The goals of the current project are to: 1) develop a generic technique which could protect the biomolecules from process- and storage-related stresses and maintain their bioactivity, 2) use the functional scaffold platform to understand the effects of biophysical and chemical cues to stem cells, and 3) develop multiphase tissues. Our work currently focuses on design of surfactant-coated, sugar-glass nanoparticles (SGnPs) for growth factor stabilization and delivery. This technology almost entirely eliminates the problem of protein activity loss. Furthermore, the encapsulated proteins are intrinsically stabilized and protected against degradation upon storage. Significantly, these well-dispersed SGnPs do not show the unwanted burst release of proteins from the matrix. Future research will involve design of injectable nanostructured materials for delivering stem cells and creating 3D scaffolds that closely mimic the natural periodontal tissue microenvironment (topography and chemical cues). Engineering nano-medicine approaches will further be extended to include development of new drug delivery systems for the treatments of oral diseases and/or nano-probes for their detection.
For further information, please email vrc@ada.org.  

Failure Analysis of Dental Restorations

Recent years have seen the development and clinical use of many new environmentally-friendly restoration materials of natural appearance. Surprisingly, there have been few attempts to systematically relate the clinical longevity of the new dental ceramics to intrinsic material properties, and forensic studies on failed restorations are nearly nonexistent.
The main purpose of this project is to apply fractography, the analysis of fracture, to identify and evaluate the failure mechanisms of restorations from critical failure-related properties. It contributes to dentistry in a number of ways: providing the dental community with a scientific understanding of restoration failure; furnishing feedback to the manufacturers and laboratories to improve materials processing; providing information relevant to clinical procedures and placement; and laying the groundwork for mechanical testing and standards development. Standardized property testing and an interdisciplinary approach involving materials design, fractographic analyses and clinical outcomes are all applied to better the understanding of failure processes in dental materials.
For further information, please email vrc@ada.org.

Novel Dental Resin Composites with Improved Service Life

The overall goal of this project is to develop a novel dental composite restorative system superior in properties and endurance to currently used Bis-GMA/TEGDMA systems. This will be achieved by designing and producing a new composite system containing novel monomers (the polymer of which will not be susceptible to enzymatic or hydrolytic degradation), self-healing components that will significantly extend the fatigue life of these composites, and smart antibacterial components which will be activated in the oral environment only when needed. The new materials will be formulated with novel monomers containing hydrolytically stable ether groups and non-ester groups. The self-healing dental composites (SHDC) may intrinsically (triggered automatically by micro-cracking) correct the cracking and prevent it from developing into catastrophic failures, thus significantly extending the service life of the restorations. The healing chemistry and triggering mechanism will be evaluated, and the compositions of SHDC optimized based on the results of physicochemical and mechanical testing, and stability in both acidic solutions and human saliva. The antimicrobial (AM) defense system will be achieved by incorporation of a novel AM quaternary ammonium coupling agent. The comparative integrity and durability of these new materials will be evaluated based on performances in simulated oral environments with challenges including cariogenic biofilms, enzymatic degradations, thermal cycling fatigue and mechanical cycling fatigue. It is expected that the new systems will significantly exceed performances of the current commercial control materials in these challenges.
For further information, please contact Drs. Jirun Sun or Ray Bowen at: jirun.sun@nist.gov and ray.bowen@nist.gov, respectively.

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Clinical Science/Therapies 

Calcium Phosphate Remineralization Therapies

The formation and conversion of calcium phosphates are being studied for prevention and repair of dental caries and tooth sensitivity. The ADAF’s ACP patents have been licensed and marketed as toothpaste (ENAMEL CARE and MENTADENT by Church & Dwight Co.), chewing gums, confections, prophylaxis paste and fluoride varnish (ENAMEL PRO series by Premier Dental), tooth whitening (Nitewhite ACP, Discus Dental), and topical desensitizers (Quell Desensitizer by Pentron Clinical Technologies and Relief ACP by Discus Dental). Other products are currently under development. The field of remineralizing temporary cement is still available for licensing. Ongoing research is concentrating on second generation ACPs and multi-pronged approaches to prevent and/or combat caries.
For further information, please contact Dr. Ming Tung at ming.tung@nist.gov.

Cavity Preventing Chewing Gum

Dr. Anthony Volpe Research Center scientists are working to develop other calcium phosphate-based technologies that can remineralize hard tooth tissues or, at a minimum, retard caries-producing demineralization. Studies have shown that an experimental chewing gum containing α-Ca3(PO4)2 can eliminate the ability of sucrose challenged plaque to demineralize tooth enamel, thus preventing a cavity from forming or progressing. Additional studies showed that separate calcium and phosphate compounds, incorporated into gums and candies, are even more effective in producing remineralizing conditions in the mouth.
For further information, please contact Dr. Larry Chow at larry.chow@nist.gov.

Fluoride Requirements for Therapeutic Efficacy

The Dr. Anthony Volpe Research Center utilizes an automated chemical reactor which simulates oral conditions/challenges in the human mouth. This artificial 'mouth' allows for the control of simulated acid attacks, studying fluoride addition to baseline saliva, and regulation of 'as-dosed' treatments, creating conditions similar to those during tooth brushing. We use this reactor to answer some of the lingering questions about fluoride anti-caries efficacy in the mouth.
For further information, please contact Mr. Burton Schmuck at burton.schmuck@nist.gov.

Microanalytical Techniques

Micro-analytical techniques and instrumentation has been developed at the ADA Foundation's research center to study the mechanisms of dental decay by examining the composition of microscopic samples of plaque, plaque fluid, and oral tissue recovered from the oral environment. These techniques have been extensively used to develop and evaluate new anti-cavity and cavity repairing technologies. As a result of these studies, fluoride rinses and dentifrices have been 'engineered' that produce a much greater cavity fighting effect while using a very low amount of applied fluoride.
For further information, please contact Dr. Jerry Vogel at jerry.vogel@nist.gov.

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Standard-related Activities

One of the many ways the Dr. Anthony Volpe Research Center contributes to the safety and efficacy of dental products is through active involvement in both the American National Standards Institute (ANSI) and the International Organization for Standardization (ISO).  The research center's representatives, currently Dr. Gary Schumacher and Mr. Burton Schmuck, regularly attend the ADA Standard committee for dental products SCDP/ANSI meeting held in conjunction with the annual American Association for Dental Research (AADR) and/or International Association for Dental Research (IADR) meetings. They are actively involved in numerous activities (oral hygiene products, fluoride varnishes, oral rinse erosion testing, standards for fluoride measurement, metal corrosion testing, US dental terminology standards, Global Medical Device Nomenclature) and chair some of these SCDP activities. Both delegates also represent the US at the annual ISO Technical Committee (TC) 106 Dentistry meeting. Dr. Schumacher is the Secretary of the Scientific Committee on Dental Implants.

ADA Foundation researchers typically get involved in multiple laboratory experiments, document generation and revision. Additionally, the researchers synthesize and characterize NIST-certified Hydroxyapatite Standard Reference Material and dental abrasives. As part of the standard-related activities, oral rinses (mouth washes) are being evaluated for their erosion effect.  A screening method has been developed to easily predict the erosive capacity of any liquid. Unlike the conventional dental erosion measurement techniques, this approach yields faster results and is available to almost any laboratory.  The method is currently undergoing national and international multi-lab testing for incorporation into the future ANSI and ISO standards on oral rinses.
For further information, please contact Dr. Gary Schumacher or Mr. Burton Schmuck at: gary.schumacher@nist.gov and burton.schmuck@nist.gov, respectively. 

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Scientific Collaboration/Education

Through collaborations with government and industry, and by fostering mentorship within the dental education community, the Dr. Anthony Volpe Research Center provides the science and technology basis needed to improve the field of dentistry and oral health of the public. Current research/educational partnerships include the Naval Post-Graduate Dental School, National Naval Medical Center, Bethesda, Maryland; National Institutes of Health/National Institute of Dental and Craniofacial Research (NIH/NIDCR), Bethesda, Maryland ; College of Dentistry, Howard University, Washington DC; School of Dental Medicine, University of Colorado; School of Dental Medicine, Dartmouth College, New Hampshire; Dental School, Department of Bioengineering and Department of Engineering, University of Maryland; and Department of Engineering, Old Dominion University, Virginia. Forthcoming collaborations include College of Dental Medicine, Nova Southeastern University, Florida, and College of Dentistry, University of Tennessee.
For further information, please contact Dr. Gary Schumacher at: gary.schumacher@nist.gov.

The Dr. Anthony Volpe Research Center traditionally hosts Dental Student’s Conference on Research at the end of April each year. On average, close to fifty students from the US and Canada attend the meeting.  The students spend one day on the NIST campus visiting the research center, and a second day visiting the NIH/NIDCR. Plenary lectures are given by the invited speakers addressing dental school, AADR, dental industry, ADA and NIST perspectives of dental research/science. Students have multiple opportunities to interact with mentors regarding careers in dental and biomaterial research. They also present their own research to their peers and on-site researchers.  Selected ongoing Dr. Anthony Volpe Research Center and/or NIST projects are presented to and discussed with the attending students.
For further information, please contact Ms. Gretchen Duppins at: gretchen.duppins@nist.gov.

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Contact Us

Dr. Anthony Volpe Research Center
100 Bureau Drive, Stop 8546
Gaithersburg, MD 20899

Phone: 301.975.6806
Fax: 301.963.9143
Email: vrc@ada.org  

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