Highly charged metal ions act as catalytic centers and structural elements in a broad range of chemical complexes. The nonbonded model for metal ions is extensively used in molecular simulations due to its simple form, computational speed, and transferability. Merz et al. have proposed and parametrized a 12-6-4 LJ (Lennard-Jones)-type nonbonded model for divalent metal ions, which showed a marked improvement over the 12-6 LJ nonbonded model [1].

In this project the aim is to understand how strong dental filling materials bind to hydroxyapatite [Ca10(OH)2(PO4)6) 9] (HAP)   which makes up the matrix of the teeth and provides rigidity. In order to cure and prevent tooth damages, efficient bonding of adhesive systems to hydroxyapatite, the mineral component of enamel, are being synthesized. The bonding mechanism of self-etch adhesives is based on a chemical interaction of functional monomers (i.e., phosphoric, phosphonic, carboxylic) with calcium of HAP. The coordination number, as well as the coordination pattern of Ca2+, plays an important role in in these complexes. Information about Ca(H2O)n2+ is expected to pave the way for understanding the binding of monomers to Ca2+ by liberating the H2O molecules.

Molecular dynamics (MD) simulation is a powerful tool that provides information about biomolecular systems at the atomic level, the particle mesh Ewald (PME) method has been used when dealing with long-range interactions in MD simulations.  The findings will be essential to guide the formulation of future functional monomers and to achieve more stable chemical interaction and longer adhesive-dentin interface durability. This project is in collaboration with Prof. K. Merz (MSU).

[1] P.Li, L.F.Song and K.M. Merz,Jr, J. Phys. Chem. B 2015, 119, 883-895.