Explaining the toxicity of methacrylate monomers
Different methacrylate monomers, a major constituent of most polymer-based dental materials, are believed to hold similar toxic potential. An in vitro study comparing frequently used monomers, however, point out different cell responses to the different monomers. Read more …
Aging and strength of zirconia materials
Leaching from endodontic materials
Laboratory investigations indicated that the cytotoxic potential of root canal sealers corresponded with the degree of leaching of methacrylate-based polymeric materials. Leached components from cured materials of this type caused cells of oral origin to die. The severity of cell death increased with the time of exposure in the cell culture. Read more …
Simulating clinical fractures of all-ceramic crowns
A laboratory method was developed to mimic the cervical fractures of all-ceramic crowns seen in the clinic. By this method occlusal force was applied on crowns using abutment material with compression/expansion characteristics similar to dentine. In this way different ceramic materials may be compared with regard to the fracture risk of all-ceramic crowns. Read more …
The monomer HEMA may interfere with DNA in vitro
The cytotoxic monomer HEMA (2-hydroxyethyl methacrylate) is a common ingredient in resin-based dental restorative materials with the potential of diffusing into pulpal tissue or be released into the oral cavity. In vitro experiments using different biochemical methods indicate that the cytotoxic potential of HEMA in lung epithelial cells is mediated by DNA damage of non-oxidative origin. Read more …
Improving dentin bond strength
Collagenolytic enzymes such as matrix metalloproteinases in mineralized dentin may impair the bond between the resin restoration and the dentin. Current research focuses on the application of enzyme inhibitors to prevent the collagen degradation and improve the bond strength and durability. Read more …
Monomers from composite fillings may impair the immune response of macrophages
Experimental evidence using a macrophage cell line indicates that methacrylate monomers inhibit the release of pro-inflammatory cytokines induced by lipopolysaccharide endotoxin from gram-negative bacteria present in dental biofilms. This effect may have negative implications for the macrophage immune response. Read more …
Tooth paste ingredient causes mouth irritation
Sodium lauryl sulphate (SLS), a common ingredient in tooth paste, causes irritant inflammatory reactions in mouse buccal mucosa. Comparison with similar exposure to the hapten oxazolone indicates that the SLS reactions are different from allergy. Read more …
Battling bacteria with yellow spice and blue light – a matter of ammunition delivery
Blue light in combination with the curry spice curcumin may cause damage to pathogenic bacteria provided that the appropriate carrier is applied. The present experiments on Stafylococcus epidermidis indicate that the phototoxic effects were more pronounced for bacteria in biofilm than in solution. Read more …
Traces of composites were found in patient saliva
In vivo studies demonstrated that small amounts of methacrylate monomers were present in saliva 10 minutes after restorative treatment with a resin-based composite material. With the exception of 2-hydroxyethyl methacrylate (HEMA), the monomers were not detected after 24 hours, and all were absent after 7 days or more. Read more …
In vitro lung cell response to HEMA
Reactive methyl methacrylate monomers such as 2-hydroxyethyl methacrylate (HEMA) may be airborne in dental clinics. In vitro studies on rat alveolar cells showed HEMA-induced cell death and other pathological reactions. These reactions were counteracted by an antioxidant (vitamin C) and a specific inhibitor of the cytochrome p450 enzyme, indicating a biotransformation of HEMA to a highly reactive intermediate. Read more …
