Amalgam is one of the popular alternatives widely used in dental practice. Amalgams are so popular because they are cheap and easy in use in contrast to other materials (Phinney and Halstead, p. 145). Recent years, dentists argue effectiveness and safety of these materials (Bird and Robinson, p. 136). The articles selected for analysis examine the impact of dental amalgams on neuropsychological function in children and adults. Both article state that the main problem caused by amalgam fillings is high toxicity of mercury and its negative impact on human body.
The article Dental Amalgam Restorations and Children’s Neuropsychological Function describes impact of amalgam fillings of children’s health and possible threats caused by mercury. The authors claim that “the total number of tooth surfaces with amalgam filings was unrelated to clinical neurological signs (e.g., tremor, coordination, station, gait, strength, sensation, muscle stretch reflexes, or indices of peripheral neuropathy), although it was associated with vibrotacile sensation in nondiabetic participants” (Bellinger et al, p. 441). The researchers prove that elemental mercury toxicity has lately assumed a new dimension. Some critics of current dental practices assert that silver filings, which contain a large percentage of mercury, release mercury vapor, especially during chewing, and that the inhaled vapor engenders a broad spectrum of medical and psychological illness. Amalgam dental restorations have been assailed since their introduction in the middle of the last century, but many patients now seek their removal because they are convinced, despite no cogent evidence that they are source of illness (Bellinger et al, p. 443). Their urinary mercury levels typically fall considerably below the maxima set for workplace exposure. Furthermore, the process of removal itself raises urinary levels of mercury Infants and young children seem especially vulnerable to mercury, and display a syndrome, characterized by irritability and erythema (Bird and Robinson, p. 440).
The article Subcutaneous Injection of Mercury discusses the impact on amalgam fillings on health of adults and their reproductive function. The authors examine impact of mercury on health and state that the developing brain may be exquisitely susceptible to organic mercury, the hazards of gestational exposure to mercury vapor are equivocal. Mercury evaporating from amalgam reconstructions apparently traverses the placenta as readily as it passes into the brain. In some cases, improvements of symptoms that patients related to dental amalgam filings have been reported following the removal of the fillings. “Concentrations in blood and urine after ingestion of mercury remain low because very little is absorbed. However, mercury causes sterile, inflammatory, and necrotic reactions resulting in abscesses and granulomas” (Prasad, p. 1327). However, chronic mercury intoxication is usually noticed at urinary mercury concentrations exceeding 1,000 nmol/L, levels far higher than those reported in cases of oral galvanism (amalgam disease). Any reaction due to mercury must therefore be due to a local accumulation, to date unknown biological mechanism, or a sensitivity in certain individuals who react to levels far lower than what is currently accepted as possible (Bird and Robinson, pp. 593-594).
There are no significant differences between information presented in both studies, but Prasad (2004) underlines a negative impact of amalgam fillings and mercury on human health while Bellinger et al (2007) prove a negative impact of mercury on neuropsychological function only. The information from the research studies show that amalgam fillings creates is a significant hazard only when inhaled. The main problem with amalgam fillings is that mercury selectively damages the developing brain. Often a child exposed to organic mercury in utero appeared fairly normal at birth, with only slight abnormalities of reflexes and muscle tone, but later had seizures, long delays in learning to walk and talk, and severe clumsiness. At lower-dose levels, the only observed effects were abnormal muscle tone and reflexes and mild developmental retardation when retested at an older age (Bird and Robinson, p. 596; Phinney and Halstead, p. 146).
The most important information presented by both steadies is that the impact of amalgam fillings on human health is understudied, but dentists and clinicians should take into account substantial analysis of mercury and its toxicity. Mercury interferes with cell division and migration of cells in the developing brain. Studies have shown that cells in the developing brain stop in the middle of cell division when exposed to organic mercury. In addition, methylmercury binds to DNA and interferes with the copying of chromosomes and production of proteins, processes that are essential to life (Bird and Robinson, p. 596-597). Symptoms include a rash and peeling of the skin of the hands and feet, irritability, photophobia (being bothered by bright light), excessive hair growth, and profuse perspiration. This syndrome is seen when mercury is used as a disinfectant in diaper laundries or when mercuric salts are applied to the baby’s skin as a disinfectant. This syndrome seems to be an allergic-type reaction to mercury. Researchers compare amalgam fillings and positing caused by mercury with the impact of methyl mercury found in food. Biological processes gradually convert methylmercury to inorganic mercury, which is eliminated in urine and feces. The half-life of mercury in the human body is estimated to be 70–80 days. The half-life is the time it takes to eliminate one-half of the body burdens of mercury. While the mercury is in the body, it is not only in blood but crosses the blood-brain barrier, where it can damage the nervous system.
The article Dental Amalgam Restorations is important for me because it vividly portray an impact of amalgam filings and mercury on human body. So it is important to keep mercury exposure low. To eliminate mercury is one factor in how much mercury exposure the government agencies say is safe (Prasad 1328). A major difference between mercury and lead is that mercury is eliminated from the body rather than being stored in bones and teeth, as lead is. Mercury can damage male fertility, men occupationally exposed to elemental mercury vapor did not have any apparent. decrease in fertility compared to a group of unexposed men, nor did their children have a greater risk of malformations (Bird and Robinson, p. 596). Mercury can be toxic to the fetus. And studies in women, mostly dental assistants, have found conflicting results as to whether elemental mercury increases the risk of spontaneous abortion.
It is possible to conclude that that there is no scientific support for the belief that amalgam fillings caused systemic diseases. Nevertheless, the debate is likely to continue at least until other reasonable explanations for mercury toxicity are found. Recent progress in the field of neuroendocrine immune interactions and awareness of the interplay between mental and physical processes may in the future offer a better understanding of negative impact of mercury on humans. Dental Amalgam Restorations better presents information taking into account a particular age group and direct impact of mercury on children.
- Bellinger, D.C. et al. Dental Amalgam Restorations and Children’s Neuropsychological Function: The New England Children’s Amalgam Trial. Environmental Health Perspectives 115 (2007): 440-460.
- Bird, D.L., Robinson, D.S. Torres and Ehrlich Modern Dental Assisting. W.B. Saunders Company; 7 Har/Cdr edition, 2002.
- Phinney, D. J., Halstead, J.H. Delmar’s Dental Assisting: A Comprehensive Approach. CENGAGE Delmar Learning; 2 edition, 2003.
- Prasad, V.L. Subcutaneous Injection of Mercury: “Warding off Evil” Environmental Health Perspectives 112 (2004): 1326-1330.