Computational study of the relative stability of some glass-ionomer cement-forming molecules

Abstract

This work is part of a larger study whose main objective was to find a series of promising molecules to be used as glass-ionomer-type materials. The project was divided into 3 successive stages; the results of the first stage have been previously published and were used to continue the study. The molecules evaluated in the second stage were constructed by adding a glycidyl methacrylate molecule to the carboxylic groups of the polyacids selected in the previous stage. The modeling was done using the density functional theory for M06-2X/6-311G(d,p). The results indicate that the addition over the carboxylic groups of the fraction of the molecule, corresponding to itaconic acid, is thermodynamically favored. The final stage was modeled with the M06 functional and consisted of obtaining basic structures of glass-ionomer-type materials, by acid-base reaction between the molecules resulting from the second stage with individual ions of Ca (2 +), Zn (2 +), or Al (+ 3). It was concluded that aluminum atoms generate more compact structures that would correlate with more resistant materials.

Keywords: Dental cement; Glass-ionomer; Glycidyl methacrylate; M06; Polyacids.

Fig. 1

Nomenclature of the acid groups that could react with the GM; the structure of the AA-IA-MBA is shown as an example

Fig. 2

Reaction mechanism between the polyacid and GM

Fig. 3

Optimized molecular structure of the reaction product of MBA-1 with GM in the different carboxyl groups. a Position 1, b position 2, c position 3, d position 4

Fig. 4

General representation of the acid–base reaction for the formation of the basic structure of the glass ionomer; M: Ca, Zn, Al; n = 2 or 3

Fig. 5

Molecules optimized to M06/6-311G(d,p) of MBA-1-GM1 with cations. a Zn, b Ca, c Al