The primary objectives of this project are to better understand the factors that lead to the development of secondary caries and to identify strategies to increase the service life of resin composite restorations. Restoration replacements due to secondary caries occupies a large portion of the dentist's practices. In 1999, 86 million composites were placed by dentists in this country and 122.7 million in 2006. The average replacement time is now only 5.7 years. Significant improvements in the long-term integrity of so many restorations could save the American people (by reducing costs of replacing restorations) many times the amount of money required to support this work. There is tremendous significance in the successful pursuit of this endeavor to benefit so many millions of people. We propose to study the effects of biofilm activity and dental resin composite compositions on the development of secondary caries. We will use a bioreactor model that utilizes conditions found in the oral environment to understand the role of microbial biofilms, salivary pellicles, and cyclic loading in the processes of secondary caries formation. While the bioreactor model establishes the conditions for the cyclic remineralization/demineralization attacks, we will use a variety of oral-simulating challenges and analytical methods to assess their effects on composite-restored teeth. We hypothesize that major contributors to defects at restoration margins include: interfacial stresses from contractions induced by polymerization shrinkage of resins, salivary esterases, acidogenic microbe-generated biofilms, and deformations from cyclic loading and oral thermal fluctuations. These can lead to subsequent staining, secondary caries, fractures, or other problems. The long-term goals of this project are to identify and prepare an optimally cross-linking composite composition resin that can restore defective teeth and defy environmental degradation (Aim 1);determine the effects of polymerization shrinkage on the development of degradation at the tooth-composite interface (Aim 2);understand the roles of salivary pellicles and microbial biofilms in the etiology of secondary caries'association with composite restorations (Aim 3);and develop beneficial biofilms in synergy with fluoride therapies that have the potential of retarding the onset of secondary caries (Aim 4). Our goal is to understand the physical, chemical and biological factors that determine the length of time a restoration lasts. With this understanding, we will develop more stable resin-based composites and methods to prevent the decay that limits the success of composite restorations.

Public Health Relevance

This project is focused on developing strategies to increase the service life of resin composite restorations. Our goal is to understand the physical, chemical and biological factors that determine the length of time a restoration lasts. With this understanding, we will develop more stable resin-based composites and methods to prevent the decay that limits the success of composite restorations.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE021391-02
Application #
8141306
Study Section
Special Emphasis Panel (ZDE1-JH (19))
Program Officer
Drummond, James
Project Start
2010-09-10
Project End
2011-10-31
Budget Start
2011-09-01
Budget End
2011-10-31
Support Year
2
Fiscal Year
2011
Total Cost
$18,900
Indirect Cost
Name
American Dental Association Foundation
Department
Type
DUNS #
789085941
City
Chicago
State
IL
Country
United States
Zip Code
60611
Carey, Clifton (2015) Plasticizer Effects in the PVC Membrane of the Dibasic Phosphate Selective Electrode. Chemosensors (Basel) 3:284-294
Gonzalez-Bonet, Andres; Kaufman, Gili; Yang, Yin et al. (2015) Preparation of Dental Resins Resistant to Enzymatic and Hydrolytic Degradation in Oral Environments. Biomacromolecules 16:3381-8
Carey, Clifton M (2014) Focus on fluorides: update on the use of fluoride for the prevention of dental caries. J Evid Based Dent Pract 14 Suppl:95-102
Carey, Clifton M; Holahan, Erin C; Schmuck, Burton D (2014) Analysis of 1-Minute Potentially Available Fluoride from Dentifrice. J Res Natl Inst Stand Technol 119:602-609
Carey, Clifton M (2014) Tooth whitening: what we now know. J Evid Based Dent Pract 14 Suppl:70-6
Carey, C M; Coleman, S S (2014) Method for the analysis of total fluoride in fluoride-releasing dental varnishes. Caries Res 48:306-11
Schmuck, B D; Carey, C M (2010) Improved Contact X-Ray Microradiographic Method to Measure Mineral Density of Hard Dental Tissues. J Res Natl Inst Stand Technol 115:75-83