Dental Tribune Indian Edition

8 Dental Tribune Indian Edition - July 2013News Asia Pacific SEATTLE, USA: Researchers have discovered that common genetic va- riants of metallothionein (MT), a protein that has the capacity to bind heavy metals, increase susceptibili- ty of children to mercury toxicity from dental amalgam and other sources. In a study of 330 children, they found that boys carrying the variants were more prone to neuro- behavioral deficits associated with mercury. The study included 164 boys and 166 girls aged 8 to 12 who participa- ted in the Casa Pia Study of the He- alth Effects of Dental Amalgam in Children, a study investigating the he- alth effects of low-level mercury ex- posure conducted between 1996 and 2006 among students of the Casa Pia school system in Lisbon, Portugal. Scientists at the University of Wa- shington evaluated whether MT1M and MT2A gene status, genes that have been reported to alter mercury toxicokinetics in adults, affected the relationship between urinary mer- cury concentration and neurobeha- vioral functions in children. They evaluated the urinary mercury levels and neurobehavioral performance of the children annually from baseline through seven years of follow-up af- ter initial placement of dental amal- gam or composite resin tooth fillings. Eighty-one boys and 74 girls received composite fillings, while 83 boys and 92 girls received amalgam fillings. Among boys, numerous significant interaction effects between the ge- netic variants of MT1M and MT2A and mercury exposure were observed, spanning multiple domains of neuro- behavioral function, the researchers said. Impaired performance was no- ticed primarily within the domains of visual spatial acuity and learning and memory, with some additional impacts on attention and motor fun- ction. However, all associations were restricted to boys with MT1M and MT2A variants in particular, althou- gh mercury exposure from dental amalgam was comparable among boys and girls. The authors said that the findings may have important public health im- plications for future strategies aimed at protecting children and adolescents from the potential health risks asso- ciated with mercury exposure. The study population had an avera- ge IQ score of 86 and relatively higher urinary mercury at baseline, implying higher pretrial mercury exposure. The researchers suspected that exposures associated with fossil fuel combu- stion for multiple uses within the lo- cal urban environment were possible sources of mercury. In addition, fish consumption, a source of inorga- nic mercury, could have contributed to elevated urinary mercury levels among the children. According to the researchers, Portugal has the highest fish consumption per capita in Euro- pe. More than 60 percent of parents or caregivers of the children in the study reported that their children consumed fish on a weekly basis. The study, titled “Modification of Neurobehavioral Effects of Mercury by Genetic Polymorphisms of Metal- lothionein in children,” was published online on July 1 in the Neurotoxico- logy and Teratology journal.DT Researchers investigate neuro- behavioral effects of dental amalgam fillings * Source: GfK and SDM market data 2010 for LuxaCore The Nr.1 in Germany and USA!* No other core build-up material comes closer to the natural properties of dentine than the new LuxaCore Z-Dual: This premium composite for core build-ups and post cementations cuts like dentine. LuxaCore Z-Dual is the first material of its category that combines true DMG-patented nano technology and zirconium dioxide. With LuxaPost, the new glass fiber reinforced and pre- silanized composite post, DMG offers the perfect partner for LuxaCore Z-Dual. www.dmg-dental.com Yet even closer to nature – LuxaCore Z. AZ_LxCZ_A4_E_1301.indd 1 01.02.13 14:24