[Occupational risk due to use of mercury in dentistry: a bibliographic review]. / Exposição ocupacional por uso de mercúrio em odontologia: uma revisão bibliográfica.

The aim of this study is to present data concerning hazardous waste management in the health area, with emphasis to the utilization of mercury in dentistry. The study was based on a bibliographic review regarding the use of mercury in dental fillings and its potential toxicological risks for patients and due to occupational exposure. The studies also take into consideration national and international recommendations on the use of mercury and its occupational exposure limits. The review of the literature reveals the potential toxic effects of mercury both on the environment and on human health. Given that the use of dental amalgam is still very frequent in dentistry, there is a need for safety regulations in order to minimize the risks posed by dental amalgam in dentistry proceedings based on technical guidelines for its use, discard and final disposal.

Optimizing the procedure for mercury recovery from dental amalgam.

Mercury, as any other heavy metal, may cause environmental damages due to its accumulation and biotransformation. Dental offices, whether private or institutional, use dental amalgam as a restorative material on a daily basis. Dental amalgam is composed of mercury (50%), silver (30%) and other metals. Approximately 30% of the amalgam prepared in dental offices (0.6 g per capsule) are wasted and inadequately discarded without any treatment. Methods for mercury recovery have been proposed previously, using high temperatures through exposure to direct flame (650 degrees C), long processing time, and hazardous reagents as potassium cyanide. The purpose of this study was to develop a method to replace the direct flame by an electrical mantle in the process of mercury recovery. Results showed an average mercury recovery of 90% from 2 kg of amalgam after 30 minutes of processing time, thus optimizing the procedure. The proposed modifications allowed a significant reduction in processing time and a mercury recovery with high purity. The modified process also provided minimization of operator exposure to physical, chemical and ergonomic hazards, representing a technological advance compared to the risks inherent to the original method. It also provided environmental health and economy of energy resources by replacing a finite energy source (fossil and organic) by a more environmentally appropriate electric source, resulting in significant improvement of the procedure for mercury recovery from dental amalgam.

Exposição ocupacional por uso de mercúrio em odontologia: uma revisão bibliográfica / Occupational risk due to use of mercury in dentistry: a bibliographic review

Este trabalho visa apresentar dados referentes ao gerenciamento de resíduos perigosos na área da saúde, com ênfase no uso de mercúrio em odontologia. Foi elaborado com base numa revisão bibliográfica sobre o uso do mercúrio em amálgama dentário e seus potenciais riscos toxicológicos ligados à exposição, tanto de profissionais quanto de pacientes. Os estudos levantados baseiam-se também em recomendações de alguns organismos internacionais e nacionais em relação ao uso do mercúrio e seus limites de exposição ocupacional. Os dados da literatura revelam o potencial tóxico do mercúrio, tanto para o ambiente quanto para a saúde humana. Tendo em vista que o amálgama ainda é muito utilizado na odontologia, considera-se necessário uma tomada de decisão político-administrativa que vise minimizar os riscos relacionados ao uso de amálgama em procedimentos odontológicos, voltados para a segurança ocupacional, dos indivíduos e do ambiente, baseada em diretrizes e orientações técnicas sobre seu uso, descarte e disposição final.

The aim of this study is to present data concerning hazardous waste management in the health area, with emphasis to the utilization of mercury in dentistry. The study was based on a bibliographic review regarding the use of mercury in dental fillings and its potential toxicological risks for patients and due to occupational exposure. The studies also take into consideration national and international recommendations on the use of mercury and its occupational exposure limits. The review of the literature reveals the potential toxic effects of mercury both on the environment and on human health. Given that the use of dental amalgam is still very frequent in dentistry, there is a need for safety regulations in order to minimize the risks posed by dental amalgam in dentistry proceedings based on technical guidelines for its use, discard and final disposal.

Optimizing the procedure for mercury recovery from dental amalgam

Mercury, as any other heavy metal, may cause environmental damages due to its accumulation and biotransformation. Dental offices, whether private or institutional, use dental amalgam as a restorative material on a daily basis. Dental amalgam is composed of mercury (50 percent), silver (30 percent) and other metals. Approximately 30 percent of the amalgam prepared in dental offices (0.6 g per capsule) are wasted and inadequately discarded without any treatment. Methods for mercury recovery have been proposed previously, using high temperatures through exposure to direct flame (650°C), long processing time, and hazardous reagents as potassium cyanide. The purpose of this study was to develop a method to replace the direct flame by an electrical mantle in the process of mercury recovery. Results showed an average mercury recovery of 90 percent from 2 kg of amalgam after 30 minutes of processing time, thus optimizing the procedure. The proposed modifications allowed a significant reduction in processing time and a mercury recovery with high purity. The modified process also provided minimization of operator exposure to physical, chemical and ergonomic hazards, representing a technological advance compared to the risks inherent to the original method. It also provided environmental health and economy of energy resources by replacing a finite energy source (fossil and organic) by a more environmentally appropriate electric source, resulting in significant improvement of the procedure for mercury recovery from dental amalgam.