Degradation of a dental filling material after high caries challenge

Abstract

New types of copolymers using monomers which form inorganic polymers network (glasslike) and organic networks have been developed, known as ormocers. The aim of this work was to study how a particular dental filling material is degraded when subjected to a caries challenge by using low pH solutions. The supernadants were studied by HPLC to detect the presence of molecules from the resin, while the changes of the material surface were evaluated by contact angle. An organic modified ceromer (ormocer) called Definite ® (Degussa ) was tested. Samples were built following manufacturer's instructions. After pH cycles, solutions were injected in a HPLC. The contact angle was obtained using a goniometer after and before the cycles. HPLC results showed material degradation, only detected in acid solutions. Bis-GMA and TEGDMA were detected in Definite ® residues. Means and S.D. of contact angle were (p < 0,05): baseline: 85.16° ± 3.90° and after pH cycles: 69.77° ± 7.12°. The authors concluded that an ormocer filling material degraded on a caries simulated environment.

Dual-curing, self-adhesive resin cement: influence of the polymerization modes on the degree of conversion and microhardness

“…These are related to the symetric and assymetric stretching of the ester carbonyl, double linkage of the vinyl monomer and stretching and bending of the C = C and C -H links of the aromatic ring. Thus, the liquid phase seems to contain monomers of the unsaturated ester type, and considering the absorptions with reference to the aromatic ring, one may conclude that the monomer Bisphenol-A diglycidylether methacrylate -Bis-GMA, usually employed as the main vinylic monomer in the formulation of dental restoration composites, is one of the monomers employed in the formulation of the cement [33][34][35] .…”

Degree of conversion versus the depth of polymerization of an organically modified ceramic dental restoration composite by fourier transform infrared spectroscopy

“…11 An ormocer is a hybrid ceramic composite in which the main chain is formed by polysiloxane linkages containing pendant unsaturated carbon chain molecules. 12 Such structures can be considered prepolymers and are therefore less susceptible to polymerization contraction because of a lower number of polymerization sites. Additionally, an ormocer is expected to present higher biocompatibility than standard BisGMA-based composites as well as lower sensitivity to the polymerization depth.…”