Composite resin restorative materials were introduced to the dental profession approximately thirty years ago. Since that time, incremental improvements in the properties of these materials have made new treatment modalities possible. There have been gradual changes in the clinical failure modes of these materials, due in part to material improvements, and in part to more aggressive treatment planning. The properties of these materials rely on the strengthening and toughening of an organic matrix through the addition of silane-coupled glass of ceramic particles. Recently, fiber-reinforced restorative materials have been introduced. Although a considerable amount of data has been collected concerning the effects of matrix cure, filler permit the rational design of new composites. Manipulation of filler-matrix interphase elastic properties has been hindered by experimental difficulties. Although the fast-fracture, fatigue, and wear behavior of proprietary and experimental composites have been studied, there is a lack of a design criterion or probabilistic mechanical approach that would enable estimation of the clinical lifetimes of composites and other brittle dental restorative materials. The long-term goal of this research is to develop and test a model incorporating mechanical properties of materials, finite element techniques, and statistical methods that could be used for the design of new restorative composites. In pursuit, six specific aims are proposed: 1.) to produce and characterize a series of model composites utilizing a 60:40 BISGMA:TEGDMA resin matrix and a spherical or fibrous borosilicate glass filler; variables include volume fraction of iller, silane coupling, and polymerization kinetics; 2.) to produce a series of composites with low filler volume fractions but with exaggerated filler sizes in order to study effects of filler-matrix bonding, residual stress, and matrix plasticity on Mode I and wear crack propagation direction; 3.) to refine a microstructural finite element model in order to predict the elastic properties, strength, and toughness of composites; 4.) to construct a analytical model based on finite elements that is capable of predicting crack propagation directions in composites; 5.) to develop a statistical and fracture mechanics methodology for evaluating the reinforcing capability of spherical, random chopped fiber, and woven fiber reinforcement; 6.) to use the CARES/LIFE software package, with fracture and fatigue data as input, to predict failure probabilities of composites, viscous glass ionomers, and polyacid-modified resin composites when these are used to restore certain cavity preparations.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE009530-10
Application #
6150520
Study Section
Oral Biology and Medicine Subcommittee 1 (OBM)
Program Officer
Kousvelari, Eleni
Project Start
1990-07-01
Project End
2003-01-31
Budget Start
2000-02-01
Budget End
2001-01-31
Support Year
10
Fiscal Year
2000
Total Cost
$289,752
Indirect Cost
Name
Temple University
Department
Dentistry
Type
Schools of Dentistry
DUNS #
City
Philadelphia
State
PA
Country
United States
Zip Code
19122
Wang, Wenhai; Sadeghipour, Keya; Baran, George (2008) Finite element analysis of the effect of an interphase on toughening of a particle reinforced polymer composite. Compos Part A Appl Sci Manuf 39:956-964
Debnath, S; Ranade, R; Wunder, S L et al. (2004) Interface effects on mechanical properties of particle-reinforced composites. Dent Mater 20:677-86
Debnath, Subir; Wunder, Stephanie L; McCool, John I et al. (2003) Silane treatment effects on glass/resin interfacial shear strengths. Dent Mater 19:441-8
Liu, Q; Ding, J; Chambers, D E et al. (2001) Filler-coupling agent-matrix interactions in silica/polymethylmethacrylate composites. J Biomed Mater Res 57:384-93
Baran, G; Boberick, K; McCool, J (2001) Fatigue of restorative materials. Crit Rev Oral Biol Med 12:350-60
McCool, J I; Boberick, K G; Baran, G R (2001) Lifetime predictions for resin-based composites using cyclic and dynamic fatigue. J Biomed Mater Res 58:247-53
Yarovoy, Y K; Baran, G; Wunder, S L et al. (2000) Submicron-size particles of ultrahigh molecular weight polyethylene produced via nonsolvent and temperature-induced crystallization. J Biomed Mater Res 53:152-60
Baran, G R; McCool, J I; Boberick, K G et al. (1999) Size effect in resin/glass composite flexure strengths. J Oral Rehabil 26:775-80
Baran, G R; McCool, J I; Paul, D et al. (1998) Weibull models of fracture strengths and fatigue behavior of dental resins in flexure and shear. J Biomed Mater Res 43:226-33
Baran, G; Sadeghipour, K; Jayaraman, S et al. (1998) Crack propagation directions in unfilled resins. J Dent Res 77:1864-73

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