NIST Polymers Division Banner NIST Polymers Division Materials Science and Engineering Laboratory National Institutes of Standards and technology
NIST polymers logo Side bar NIST Polymers characterization group logo NIST Polymers electronics group logo NIST Polymers biomaterials group logo NIST Polymers Multiphase group logo NIST Polymers processing group logo NIST Polymers combi group logo Side bar
 Our Publication:
 Group:

 Year:


 
 
button  HOME
button  Structure-Property Relationships in Dental Polymers and Composites
     button  Nanocomposite Dental Materials
  button  Structure-Property Relationships of Hydrogels for Dental and Craniofacial Applications
  button  The Effect of an Organogelator on Bioactive Dental Composites
  button   High-throughput and combinatorial methods for measuring the mechanical properties of dental materials
button  Combinatorial Methods for Rapid Screening of Biomaterials
  button  High-throughput Method for Determining Young’s Modulus of Polymer Blends
  button  Inflammatory Cytokine Quantification of Cell-SCK Interactions via RT-PCR
  button  Peptide Derivatized SCK Nanoparticles
  button  Real-Time Polymerase Chain Reaction
  button  Gradient Library Screening of Cell-Material Interactions
  button  Surface Energy Gradients for Characterizing Cell-Material Interactions
  button  High-throughput Method for Characterizing Cell Response to Polymer Crystallinity
  button   Cellular Response to Bis-GMA/TEGDMA Vinyl Conversion Gradients
button  Metrologies for Tissue Scaffolds
  button  Focal Adhesions of Osteoblasts on Poly(d,l-lactide)/Poly(vinyl alcohol) Blends by Confocal Fluorescence Microscopy
  button   2D -->3D Cell / Scaffold Interactions
  button  Development of a Reference Scaffold
  button   In Vitro Cartilage Development
  button   Gene Expression Profiles of Cells in Response to Tyrosine Polycarbonate Blends
  button Broadband Coherent Anti-Stokes Raman Scattering (CARS) Microscopic Imaging
  button Collinear Optical Coherence and Confocal Fluorescence Microscopies
 

line 		 
 
 

The Effect of an Organogelator on Bioactive Dental Composites
 

Introduction

line
Polymeric dental composites containing amorphous calcium phosphate (ACP) are an important class of dental materials due to their potential for remineralizing dental structures and their biocompatibility. However, their application is limited by their poor mechanical properties and shrinkage stresses introduced during polymerization. Dibenzylidene sorbitol (DBS) is an organic molecule capable of physical gelation in a wide variety of dental monomers by forming three-dimensional networks. This research was aimed at determining the effect of these three-dimensional networks on conversion, shrinkage, and mechanical strength of bioactive polymeric dental composites consisting of ethoxylated bisphenol-A dimethacrylate (EBPADMA) and ACP.
 

Experimental Approach

line
 
Rheology to characterize DBS/EBPADMA gels
  • Rheology to characterize DBS/EBPADMA gels
    Fourier-transform infrared spectroscopy to monitor conversion
    Biaxial flexural tests to determine biaxial flexural strength (BFS)
  • Three-point bend to measure flexural strength (FS) and modulus (E)
  • Mercury dilatometry to measure polymerization shrinkage
  • Tensometer measurements to follow polymerization stress
  • Optical light microscopy to analyze fracture surfaces
  • Spectrophotometry to measure ion release of ACP composites
    		•

    Results
    line
     
    DBS Addition of DBS Graph Graph
    Composite sample Conversion (%) BFS (MPa) E (MPa)
    0 % DBS 77.6 ± 0.3 59.5 ± 5.7 2949 ± 368
    3 % DBS 76.2 ± 0.5 83.0 ± 3.7 3161 ± 107
    6 % DBS 76.4 ± 2.2 69.6 ± 4.4 3266 ± 159
     
    Addition of DBS:
  • significantly reduces the number and size of pore defects and may help improve dispersion of ACP
  • significantly increases the biaxial flexural strength
  • significantly reduces volumetric shrinkage and associated shrinkage stress during polymerization
  • inhibits calcium ion and phosphate ion release
    		•
     

    Future Activities
    line
  • Studies on other gelators including gelatin or silicate clays
  • Combinatorial approaches towards improved bioactive dental composites
    		•
     

    Publications
    line
  • Organogelators and their application in dental materials, Polymer Preprints (in press)
  • Reduced volumetric shrinkage of dental composites through the addition of an organogelator, Chemistry of Materials (to be submitted)
    ADAF NIDCR
    •  

    Contributors

    line
    Joseph M. Antonucci
    Elizabeth A. Wilder
    Newell R. Washburn
    Kristen S. Wilson
    Drago Skrtic
    Janet B. Quinn
     
     
     
     
     
     
     
    		 
    		 
    line
    NIST logo
    Biomaterials Group
    Polymers Division
    Materials Science and Engineering Laboratory
     
    		NIST Polymers logo