Biocompatibility of Resin-Modified Filling Materials

Abstract

Increasing numbers of resin-based dental restorations have been placed over the past decade. During this same period, the public interest in the local and especially systemic adverse effects caused by dental materials has increased significantly It has been found that each resin-based material releases several components into the oral environment. In particular, the comonomer, triethyleneglycol di-methacrylate (TEGDMA), and the 'hydrophilic' monomer, 2-hydroxy-ethyl-methacrylate (HEMA), are leached out from various composite resins and 'adhesive' materials (e.g., resin-modified glass-ionomer cements IGICsl and dentin adhesives) in considerable amounts during the first 24 hours after polymerization. Numerous unbound resin components may leach into saliva during the initial phase after polymerization, and later, due to degradation or erosion of the resinous restoration. Those substances may be systemically distributed and could potentially cause adverse systemic effects in patients. In addition, absorption of organic substances from unpolymerized material, through unprotected skin, due to manual contact may pose a special risk for dental personnel. This is borne out by the increasing numbers of dental nurses, technicians, and aentists who present with allergic reactions to one or more resin components, like HEMA, glutaraldehyde, ethyleneglycol di-methacrylate (EGDMA), and dibenzoyl peroxide (DPO). However, it must be emphasized that, except for conventional composite resins, data reported on the release of substances from resin-based materials are scarce. There is very little reliable information with respect to the biological interactions between resin components and various tissues. Those interactions may be either protective, like absorption to dentin, or detrimental, e.g., inflammatory reactions of soft tissues. Microbial effects have also been observed which may contribute indirectly to caries and irritation of the pulp. Therefore, it is critical, both for our patients and for the profession, that the biological effects of resin-based filling materials be clarified in the near future,

Evaluation of the cytotoxicity of selected conventional glass ionomer cements on human gingival fibroblasts

“…Primary cells represent clinical conditions better, but are diversified and have lower viability. 20 TheISO 10993 standard, standardizing in vitro studies, supports the use of permanent cell lines. 2,4,12 In our study, we used a standard human gingiva fibroblast line; and to reproduce conditions similar to clinical, we placed samples of materials on a semi-permeable membrane of inserts.…”

HEMA‐induced cytotoxicity: oxidative stress, genotoxicity and apoptosis

“…It has been found that each resin-based material releases several components into the oral environment. In particular, the hydrophilic monomer, 2-hydroxyethylmethacrylate (HEMA), is leached out from various composite resins and adhesive materials in considerable amounts during the first 24 h after polymerization (Geurtsen 2000). Moreover, HEMA, together with tetraethylenglycol dimethacrylate (TEG-DMA), is able to diffuse through dentine into the pulp space at significantly high concentrations in the millimolar range (Bakopoulou et al 2009).…”

Confocal Time Lapse Imaging as an Efficient Method for the Cytocompatibility Evaluation of Dental Composites

“…Resinbased dental composites may release components from the resinous matrix, which could be initially due to partial polymerization, and/or later due to degradation processes over time [1][2][3][4] . These released components come into contact with oral tissues and may have various drawbacks like urticarial and mucosal reactions 5 , development of allergy and hypersensitivity reactions in patients 6 , modifications of gingival fibroblasts morphology and reduction on type I collagen protein 7 , immunosuppression or immunostimulation on mitogen-driven proliferation of purified T-lymphocytes and spleen cells 8 and DNA damage in primary human gingival fibroblasts, which underlines their genotoxic potential 9 .…”