New Pre-reacted Glass Containing Dental Composites (giomers) with Improved Fluoride Release and Biocompatibility

Abstract

The aim of the present work was to prepare a series of novel restorative giomers and investigate the morphology, the physico-chemical properties (residual monomer, fluoride release), and the cytotoxicity of the new materials. The experimental giomers were prepared as light-cured pastes by blending different resin matrices comprising aromatic/aliphatic/urethane (di) methacrylates, with hybrid fillers containing pre-reacted glasses (PRGs), a radiopaque glass, and nano fluorhydroxyapatite. Polyalkenoic acids based on acrylic acid/itaconic acid/N-acryloyl -L-leucine modified or not with methacrylic groups, together with a superficially active glass, were used to prepare the PRGs. The fluoride ion release of the experimental giomers was investigated within a period of 60 days of storage in bidistilled water while using a fluoride ion selective electrode. Beautifil II commercial product was used as a reference. Cell cytotoxicity tests were done in vitro, in accordance with ISO 10993-122012 proceedings. Human dermal fibroblasts and umbilical endothelial vein cultures were used. The values that were obtained for cumulative fluoride release for all experimental giomers were higher than for the Beautifil II product, being more than twice the ones that were obtained for the commercial product after 60 days of storage in bidistilled water. The experimental biomaterials showed similar and/or better results when compared to the commercial one; this effect was maintained in all tested conditions.

Surface Characteristics, Fluoride Release and Bond Strength Evaluation of Four Orthodontic Adhesives

“…The metal bracket bonding procedure was conducted according to the manufacturer's indications and kept in artificial saliva for 24 h. Artificial saliva was obtained in the laboratory, simulating the salt composition of saliva, according to the following recipe: 0.4 g/L KCl, 0.4 g/L NaCl, 0.69 g/L NaH2PO4 H2O, 0.005 g/l Na2S 9H2O, 0.795 g/L CaCl2 2H2O 1.0 g/L CO(NH2)2, aqueous solution [15]. The buccal surface was etched for 30 s with 37 percent phosphoric acid at room temperature, rinsed for 15 s with water, and air dried until a white, chalky surface appeared.…”

“…For fluoride ions release, daily measurements were performed for the first 3 days and then weekly until the end of the 60 days, according to previous studies [15,16]. After each measurement, the material samples was placed in the same storage container (made of polyethylene), and kept in a thermostatic bath at 37 • C. Fluoride ion analysis was performed using a selective fluoride ion electrode (Combination Fluoride Electrode HI 4110 filled with HI 7075 electrolyte for the reference electrode, Hanna instruments).…”

Water Sorption and Solubility of Flowable Giomers

“…The experimental glass (Exp-Glass) powder is based on barium fluoro-alumino-boro-silicate glass silanized with 3-methacryloyloxypropyl-1-trimethoxy-silane (A-174 silane) from Sigma Aldrich Chemical Co. FHAP (fluorohydroxy apatite) is composed of needle-shaped nanometric particles, 15–160 nm in length and 10 nm in width. The detailed descriptions of obtaining the powders are presented by Prejmerean et al and Burtea et al [ 6 , 13 ].…”

“…Commercially, giomers have been introduced on the market by Shofu Dental (Japan) which provided different consistencies, adapted for various clinical situations: conventional (indicated for reconstruction of tooth anatomy when important portions of the dental structure are missing) and flowable giomers, with more specific indications, according to their individual consistencies: high stress areas, like class V restorations, or marginal ridges, cavity liners, and small restorations [ 3 , 4 , 5 , 6 ].…”

New Antimicrobial Biomaterials for the Reconstruction of Craniofacial Bone Defects

“…One of the most important issues of composite materials is the release of residual monomer during polymerization and afterwards. [5,6]. Giving that the residual monomer 2 of 17 is known to induce cytotoxicity and genotoxicity, as well as potential allergic response, researchers struggle to decrease residual monomer release [7].…”