Binding of self-etching monomers to hydroxyapatite: A computational approach

[Display omitted] •This study has enlighten the binding affinities of self-etching monomers on the surface of the tooth.•8 coordinated calcium triphosphate complex with 4 water molecules (8-M-4), has been found to be the most stable pre-nucleation complex.•Dissociation energies of the self-etching monomers have been calculated in order to analyze the binding strength of the monomers to the calcium ion in pre-nucleation complex 8-M-4.•The dissociation energy calculations show a similar trend to the order proposed by the previous experimental studies. The stability order obtained from the dissociation energy calculations is MDDP > MDP > CAP-P > MTEP > MEP and MAEPA > EAEPA > HAEPA.•The computational method used in this study enables us to understand the role of interactions between self-etching monomers and pre-nucleation complexes at an atomistic level, this procedure can be used widely for further evaluation of self-etching monomers. Self-etching monomers are of interest as dental adhesives due to their strong binding ability to the hydroxyapatite (HAP) component of the tooth. The strength of the interaction between the calcium in HAP and acid groups (self-etching monomers) has been widely studied using empirical approaches. However, the literature lacks a relevant computational basis to supplement such findings. Herein, self-etching monomers and pre-nucleation complexes (PNCs) that are used as a unit, representing hydroxyapatite have been modeled with quantum mechanical tools. The dissociation energies of the HAP-monomer complexes have been calculated in order to evaluate the energy required to remove monomers from the PNC. The computational procedure used in this study has enabled us to evaluate the bonding strength of phosphoric and phosphonic acid monomers to PNC in agreement with the results obtained from previous experimental studies. The protocol utilized herein can be used safely to evaluate the strength of the interaction between calcium (HAP) and self-etching monomers.