Levels of mercury in fish-eating children, with and without amalgam restoration

Abstract

Background: Mercury is a naturally occurring metal that exists in three forms: elemental (metallic), inorganic, and organic mercury. Amalgam, which is an alloy of inorganic mercury, is used as a restorative material in dentistry. Organic mercury gets ingested in the body mainly by the consumption of seafood. Mercury is also stated to cause various adverse health effects such as gastrointestinal disturbances, dermatitis, muscle weakness, and neurological disorders. In recent years, the use of amalgam has become a controversy stating the various adverse effects of mercury. Hence, the study was conducted to determine and compare the variation in levels of organic and inorganic mercury in fish-eating children before and after placement of amalgam restoration. Materials and Methods: Seventy-five subjects, 42 males (56%) and 35 females (44%) of age group ranging 7–13 years, living in South Canara district of Karnataka, India, were selected as a part of the study. Hair and urine samples were collected for estimation of organic and inorganic levels of mercury, respectively. Informed consent was collected from all the participating subjects. Results: On comparison between organic and inorganic mercury levels during the study period, the concentration of organic mercury in hair samples was greater irrespective of amalgam restorations present (1.172 and 0.085, respectively; P < 0.001). Conclusion: Thus inorganic levels of mercury do not seem to pose a threat as much as the organic levels observed in hair, which remain fairly constant for a longer period of time. Hence in a coastal region where this study was undertaken and fish being a staple food, the risk could probably be attributed to more of an organic toxicity than an inorganic one. Thus amalgam is relatively safe to be practiced and the controversy against it should be reevaluated.

Materiales de restauración dental

“…La exposición al mercurio o a los compuestos inorgánicos producen una triada, la cual consiste en: gingivitis con salivación, temblores y cambios neuropsiquiátricos; en algunos casos los temblores pueden ser tan fuertes que incapacitan al individuo. 7 Una de las restauraciones dentales más útiles disponibles es la restauración de oro fundido (alto metal noble). Estas aleaciones de oro brindan una opción fuerte de biocompatibilidad y duradera con un largo historial de servicio excepcional para el campo de la odontología.…”

Concentration of mercury levels in saliva, milk and hair of nursing mothers in southeastern Iran

“…In mothers, amalgam mercury passes through the placenta and breast milk and reaches the fetus and infant; dental amalgam llings are the largest source of mercury in fetuses and infants before vaccination (Thornhill et al, 2003;Yılmaz and Altaş, 2022). 2019) also compared people with amalgam teeth with the group without restoration teeth and reported that amalgam llings can be a stable and continuous source of organic mercury, which is much more toxic than inorganic mercury and is absorbed by the human intestine (Padmakumar et al, 2019). Human biomonitoring is a suitable tool to assess real exposure to pollutants but it takes time to consider all the absorption pathways (Esteban et al, 2015).…”

Exposure to mercury in dentistry: A safety concern

“…Međutim, u mnogim studijima pominje se da se živa možda neće akumulirati u tkivu na duži period i da se obično izlučuje iz organizma u roku od 55 dana 9 ; takođe, veruje se da nema dokaza da živa koja se oslobađa iz amalgamskih restauracija ima štetan uticaj na javno zdravlje. Veliki broj istraživača veruje da je količina žive koja se oslobađa iz restauracija manja od trenutnog zdravstvenog standarda i da ne predstavlja nikakav zdravstveni rizik, osim alergijskih reakcija 10 . Studije su pokazale da se lokalni lihenoidni tip reakcija retko viđa kao posledica amalgamskih restauracija 11 .…”

“…A large number of researchers believe that the amount of mercury released from restorations are for less than the current health standard and does not pose any health risk other than allergic reactions 10 . Studies indicated local lichenoid type of reactions is seen rarely to amalgam restorations 11 .…”