title: Mathematical modeling of cross-linking monomer elution from resin-based dental composites.
abstract: Elution of potentially toxic substances, including monomers, from resin-based dental composites may affect the biocompatibility of these materials in clinical conditions. In addition to the amounts of eluted monomers, mathematical modeling of elution kinetics reveals composite restorations as potential chronic sources of leachable monomers. The aim of this work was to experimentally quantify elution of main cross-linking monomers from four commercial composites and offer a mathematical model of elution kinetics. Composite samples (n = 7 per group) of Filtek Supreme XT (3M ESPE), Tetric EvoCeram (Ivoclar Vivadent), Admira (Voco), and Filtek Z250 (3M ESPE) were prepared in 2-mm thick Teflon moulds and cured with halogen or light-emitting diode light. Monomer elution in ethanol and water was analyzed using high-performance liquid chromatography up to 28 days postimmersion. The mathematical model was expressed as a sum of two exponential regression functions representing the first-order kinetics law. Elution kinetics in all cases followed the same mathematical model though differences in rate constants as well as the extent of monomer elution were material-, LCU-, medium-dependent. The proposed mechanisms of elution indicate fast elution from surface and subsurface layers and up to 100 times slower monomer extraction from the bulk polymer.
authors.affiliation: Department of Restorative Odontology and Endodontics, School of Dental Medicine, University of Belgrade, Belgrade, Serbia.
authors.forename: Dragica
authors.initials: D
authors.lastname: Manojlovic
authors.forename: Marina
authors.initials: M
authors.lastname: Radisic
authors.forename: Mila
authors.initials: M
authors.lastname: Lausevic
authors.forename: Slavoljub
authors.initials: S
authors.lastname: Zivkovic
authors.forename: Vesna
authors.initials: V
authors.lastname: Miletic
mesh_terms: D000180:Acrylic Resins; D000704:Analysis of Variance; D002851:Chromatography, High Pressure Liquid; D003188:Composite Resins; D007700:Kinetics; D008962:Models, Theoretical; D011140:Polyurethanes
chemical_list: D000180:Acrylic Resins; C029012:Composite Dental Resin; D003188:Composite Resins; D011140:Polyurethanes