Please activate JavaScript!
Please install Adobe Flash Player, click here for download

Today AEEDC Dubai 2014

news14 AEEDC Dubai 2014 Certain products containing mercurywillbebannedfrom2020, according to a new international treaty signed by governments in Minamata in Japan. The regula- tions apply to the production and trade of batteries, cosmetics and fluorescence lamps containing the toxic material, among other prod- ucts. Amalgam dental fillings are not affected by the ban. However, the treaty agreed on a number of provisions on the phas- ing down of the controversial den- tal material. The Convention, whichwasproceededbyfiveinter- governmental negotiation rounds and set in place for adoption at a meeting in Geneva in January, was signed by 87 countries. Govern- ments now have three years to de- velop and implement national strategies to reduce or eliminate the production and industrial use of the toxic metal. Mercury emis- sion from large-scale industrial plants,themainsourceofmercury pollution worldwide, will also be controlled. Dentalassociationsreactedpos- itively to the decision, which will permit the use of amalgam as a restorative dental material for the years to come. Dr Stuart Johnston from the British Dental Associa- tion, who took part in the negotia- tions on behalf of the FDI World Dental Federation, commented: “We are delighted that the Mina- mataConventionallowsthedental profession continued access to a key restorative material. Dental amalgam is safe and effective: it has been in use for over 150 years and no studies have demonstrated any harm to human health.” He said that despite amalgam not being banned by the treaty, however, the dental profession is committed to phasing down the use of the material through the prevention of dental diseases, the development of alternative mate- rials and effective amalgam man- agement. Guidelines in this re- spectforprofessionals,healthoffi- cials and the public are currently being compiled and will be re- leased by the organisation soon. Theinitialstepshavealreadybeen taken with a pilot project launched recently by the FDI in partnership with the United Na- tions Environment Programme in East Africa that aims to train pro- fessionals in the country on man- aging and recycling amalgam waste more effectively. Amalgam remains one of the most widely used restorative mate- rials worldwide. Particularly in de- veloping countries, it is often the only affordable means of treating dental caries, despite the availabil- ity of other methods, such as atrau- matic restorative treatment. Unfor- tunately, it is also a significant sourceofmercurypollution.Recent national tests conducted in Pak- istan,forexample,foundthatlevels in urban dental hospitals and prac- tices were up to 20 times higher than acceptable levels, which was consideredlargelyduetopooramal- gam waste management. According to estimates by the United Nations Environment Pro- gramme, between 300 and 400 metric tons of mercury is used in dental fillings every year world- wide, a tenth of the world’s annual consumption. Minamata Convention bans products, Agrees to amalgam phase-down UNEPExecutiveDirectorAchimSteinerand the Japanese Minister of Environment Nobuteru Ishihara lay flowers in memorium of the Minimata victims at the Opening of the Diplomatic Conference for the Minamata Convention on Mercury. (From left to right) Nobuteru Ishihara, Minister of Environment, Japan, Achim Steiner, UNEP Executive Director, Ikuo Kabashima, Governor of Kumamoto Prefecture, and Katsuaki Miyamoto, Mayor of Minamata, posing with a plaquette commemorating the signing of the historic treaty. (DTI/Photos courtesy of ENB) Objectsinamirrorappearingtobe farther away than they are is a com- monillusionencounteredbycardriv- ers around the world every day. Mis- leadingvisualperceptionofanobject couldalsobethereasonthatdentists sometimes drill larger cavities than necessary to fill a tooth or prepare a root canal, a team of psychologists and dental researchers from Aus- tralia and New Zealand has sug- gested. In clinical field tests involving eight practising endodontic special- istsfromNewZealandandconducted in 2002 and 2006, the researchers found that dental professionals tend to fall trap to the Delboeuf illusion, which makes enclosed areas appear smaller than they actually are when seeninalargercontext.Intheircase, a cavity drilled into a tooth appeared to be smaller when the surrounding tissuewasinrangeoftheparameters of the illusion, leading to more healthy tissue being removed at the expenseofpatients. Theresearcherssaidinthereport that it remains unknown whether dentists are aware of this when drilling but recommended that their findings be incorporated into the early stages of clinical training to de- crease the risk of cracking or perfo- rating the root end due to having re- moved too much healthy tissue. It should also be extended to other fields of health-care treatment that could be affected by visual illusions, theysuggested. “When operating, health-care providerstrytosaveasmuchhealthy tissue as possible. It is important to know that their eyes can deceive themintoremovingmorehealthytis- sue than necessary,” lead author of the study and psychology expert from the University of Otago in Dunedin Prof. Robert O’Shea com- mented. Named after its creator, Joseph RemiLeopoldDelboeuf,aBelgiansci- entist, the illusion was first docu- mented in 1865. It has been reported tobeusedbyrestaurantstotrickcus- tomers regarding the size of their dishesbyusingsmallerplates,among otherthings. For the latest study, more than 20 extracted and root-filled teeth were treatedbyeachparticipant,whohad notbeeninformedabouttheparame- ters of the illusion. The participants were asked to remove as little tissue aspossiblewhenpreparingtheteeth and to use their usual hand instru- ments. Dentists prone to visual illusion The sound of a dental drill or suction system evokes a feeling of fear in almost every tenth dental patient. New findings presented by Japanese researchers at a re- cent neuroscience meeting in the US have revealed new insights into how the brain of anxious pa- tients may react during treat- ment. Using functional magnetic res- onance imaging, a neuroimaging procedure to measure brain activ- ity, the researchers found stronger activity in the left cau- date nucleus in anxious patients when playing them sounds of var- ious dental instruments. When neutralsounds,likeaFrenchhorn or pure tone, were played, how- ever, activity in this region was found to be significantly lower. No significant neural activity was detected when the same sounds were played to a control group of non-anxious patients. In- stead, these patients showed stronger brain activity in the right and left superior temporal gyri, a part of the brain usually as- sociated with auditory process- ing and other neural functions. “Recent studies have indicated that the basal ganglia, including the caudate nucleus, may play a roleinlearningandmemoryfunc- tions. The subjects in the dental fear group therefore may be re- ceiving feedback from memories of sounds of dental treatment,” re- searcher Hiroyuki Karibe from the Nippon Dental University’s Department of Pediatric Den- tistry in Tokyo suggested. He said that the findings, which have not been published yet, could be ap- plied to assess the effectiveness of conventional interventions for dental fear, such as cognitive be- haviour therapy. The study is the first to have measured how the sounds of den- tal instruments relate to brain ac- tivity. It confirms the assumption that dental anxiety is mainly due to reasons other than the fear of experiencing pain through sur- gery. Dental memories haunt brains Cavities made by the participants of the study were often made too large, which could be due totheDelboeufillusion,whichmakesenclosedareasappearsmallerthantheyactuallyarewhen seen in a larger context. (DTI/Photo courtesy of Robert P. O’Shea, Australia)

Overview