The strength, durability and impermeability of the dentin-restoration interface are of critical importance during tooth restoration because any post-restoration breakdown of this interface opens up pathways for toxins and bacteria to penetrate into the pulp. In recent years, there has been considerable focus on the formation of hybridized dentin at this interface by the infiltration of adhesives into the dematerialized dentin during bonding. Analytical and morphological studies have revealed the hybrid layer to be an intimate molecular mixture of collagen fibrils and adhesive material. During bonding adhesive monomers are allowed to permeate into the vacant spaces on the subsurfaces of dentin opened up by demineralization. During infiltration into the sub-surface of dentin, the monomer interacts with collagen fibrils and is subsequently polymerized to provide strength to the hybridized structure. Spectrographic investigations have not been able to fully characterize the interface structure, especially the adhesive-collagen interaction. Different investigators have arrived at conflicting conclusions based on similar or different experiments. One innovative approach to study hybridized dentin is to probe potential interactions through computer simulations. The research outlined in this application is a continuation of a novel method of computer-aided biomimetic modeling of collagen and monomer structures and their interactions. The applicant developed this method in a feasibility study supported by the NIH through an AREA grant. In this study, optimized conformational states of model structures of the triple helical collagen receptor and the monomer molecules and the complex generated by their interaction will be visualized and their interactions in the presence of a solvent analyzed at the atomic level. The steric and electrostatic complementarity of the reactive sites of the ligand receptor molecules will be characterized. The interaction energy for the formation of the collagen-ligand complex will be calculated as the cumulative effect of van der Waals, electrostatic and hydrogen bonding interactions. These energy contributions will be analyzed to determine the predominant mode of interaction for each monomer. Binding studies between the ligands and collagen will be conducted by:1) a novel immunochemical binding assay developed by us; and 2) isothermal titration calorimetry, and related to computed interaction energy values.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE014370-03
Application #
6878553
Study Section
Special Emphasis Panel (ZRG1-OBM-1 (01))
Program Officer
Mcinnes, Pamela M
Project Start
2003-05-07
Project End
2007-04-30
Budget Start
2005-05-01
Budget End
2006-04-30
Support Year
3
Fiscal Year
2005
Total Cost
$221,588
Indirect Cost
Name
University of Medicine & Dentistry of NJ
Department
Dentistry
Type
Schools of Dentistry
DUNS #
781265475
City
Newark
State
NJ
Country
United States
Zip Code
07101
Vaidyanathan, J; Vaidyanathan, T K; Ravichandran, S (2009) Computer simulated screening of dentin bonding primer monomers through analysis of their chemical functions and their spatial 3D alignment. J Biomed Mater Res B Appl Biomater 88:447-57
Vaidyanathan, T K; Vaidyanathan, Jayalakshmi (2009) Recent advances in the theory and mechanism of adhesive resin bonding to dentin: a critical review. J Biomed Mater Res B Appl Biomater 88:558-78
Munisamy, S; Vaidyanathan, T K; Vaidyanathan, J (2008) A bone-like precoating strategy for implants: collagen immobilization and mineralization on pure titanium implant surface. J Oral Implantol 34:67-75
Vaidyanathan, J; Ravichandran, S; Vaidyanathan, T K (2007) Computational analysis of adhesion of primer ligands to dentinal collagen: effect of spacer groups in ligand and amino Acid residue sequence differences in collagen. Curr Drug Discov Technol 4:150-61
Vaidyanathan, Jayalakshmi; Vaidyanathan, Tritala K; Kerrigan, John E (2007) Evaluation of intermolecular interactions of self-etch dentin adhesive primer molecules with type 1 collagen: computer modeling and in vitro binding analysis. Acta Biomater 3:705-14