Mercury levels and discharge in waste water from dental clinics
It was concluded that Hg is released with the waste water from dental clinics. Several hundred grams of Hg clinic−1 may be discharged annually with the waste water. Installation of efficient amalgam separators may reduce the Hg outlet markedly.
Dental amalgam – environmental aspects
Major amalgam particles from trituration surplus of those produced during the carving and burnishing of new amalgam restorations are generally collected in coarse filters and sold for refinement. Minor amalgam particles released by production of new fillings or by removal of old restorations partly sediment in tubes and drains. The remaining particles are carried with the waste water stream to the local purifying plant.
Mercury from dental amalgams: exposure and effects
There is no doubt that dental mercury should be taken into consideration as a possible etiological factor when considering neurological, immunological and endocrinological diseases of unknown etiology. Protective measures during amalgam removal and prospects for alternative dental materials are discussed.
Particulate inhalation during the removal of amalgam restorations
The use of a rubber dam, together with water spray and high-velocity evacuation, was responsible for a further significant reduction of exposure to particles when compared with water spray and high-velocity evacuation alone. The dentist, however, was exposed to moderate levels of fully respirable particles for all conditions tested. It is therefore recommended that all dental personnel wear face masks while removing existing amalgam restorations.
Mercury vapour released during the removal of old amalgam restorations
To reduce the exposure of the dentist and the assistant to volatile mercury it is essential to establish high volume aspiration of the patient’s mouth in addition to effective water cooling of the bur.
Mercury vaporization during amalgam removal
Using water spray coolant can reduce mercury vapor levels caused during amalgam removal and therefore lessen one source of ambient mercury vapor in the dental office. With wet cutting, mercury levels generally decreased as distance from amalgam cutting increased. Dry cutting caused similar levels of mercury vaporization when measured within 24 inches. A mercury-filtering mask (Mercury Vapor Respirator, Item No. 8707, 3M Co., St. Paul, Minn.) is commercially available and recommended for use during amalgam removal.