Amalgama y mercurio. Visión y evolución en la odontología restauradora actual / Amalgam and mercury. Vision and evolution in current restorative dentistry

La amalgama dental ha sido un material restaurador muy confiable, de gran utilidad en la odontología y que, aún con su gran aceptación y amplio uso en la profesión dental, ha presentado siempre muy limitado reconocimiento profesional, por su poca o nula capacidad estética o de color de diente y por las «guerras¼ que ha tenido que librar a través de sus muchos años de vida. El mercurio es un componente importante en la mezcla de la amalgama dental, y su presencia ha sido uno de los factores preponderantes que han causado el detrimento injusto del uso de este material restaurador, que ha demostrado un comportamiento clínico excelente en sus casi 200 años de vida (AU)

Dental amalgam has been a very trustable restorative material, highly utilized in dentistry and although with high acceptance and ample use in the dental profession, it has always had to deal with limited professional acknowledgement due to little or poor esthetic and lack of tooth color and because of the many «wars¼ it has to fight in the many years of life. Mercury is a very important component of the mix in the dental amalgam and its presence has been one of the key factors that has caused the unjustified detriment of the use of this restorative material that has shown an excellent clinical behavior in the almost 200 years of life (AU)

Increased mercury emissions from modern dental amalgams.

All types of dental amalgams contain mercury, which partly is emitted as mercury vapor. All types of dental amalgams corrode after being placed in the oral cavity. Modern high copper amalgams exhibit two new traits of increased instability. Firstly, when subjected to wear/polishing, droplets rich in mercury are formed on the surface, showing that mercury is not being strongly bonded to the base or alloy metals. Secondly, high copper amalgams emit substantially larger amounts of mercury vapor than the low copper amalgams used before the 1970s. High copper amalgams has been developed with focus on mechanical strength and corrosion resistance, but has been sub-optimized in other aspects, resulting in increased instability and higher emission of mercury vapor. This has not been presented to policy makers and scientists. Both low and high copper amalgams undergo a transformation process for several years after placement, resulting in a substantial reduction in mercury content, but there exist no limit for maximum allowed emission of mercury from dental amalgams. These modern high copper amalgams are nowadays totally dominating the European, US and other markets, resulting in significant emissions of mercury, not considered when judging their suitability for dental restoration.

Neurological disease or intellectual disability among sons of female Swedish dental personnel.

OBJECTIVE: Prenatal exposure to elemental mercury may be a potential hazard for the offspring of female dental personnel working with dental amalgam. The aim of this study was to investigate whether potential in utero exposure to mercury might have affected the development of nervous system of the sons of Swedish female dental personnel leading to an increased risk of neurological disease or intellectual disability. MATERIAL AND METHODS: We used national Swedish registers to investigate risks for diseases potentially related to adverse effects on neurodevelopment. Sons of female dentists (n=1690) and dental nurses (n=10,420) were compared with cohorts consisting of sons of other female healthcare personnel. Due to changes in mercury exposure in dentistry during the study period, analyses were stratified by decade of birth. Hazard ratios (HRs) were calculated using Cox proportional hazard models. RESULTS: We found no elevated risk for neurological disease, epilepsy or intellectual disability among the sons of dental personnel during any of the decades studied. HRs for neurological disease among the dental nurse cohort were even below 1.00 during the 1970s and 1980s. A low number of events resulted in uncertainty regarding results in the dentist cohort. CONCLUSIONS: We did not find any support for the hypothesis that mercury exposure in Swedish dentistry during the 1960s, 1970s or 1980s had any effect on the incidence of neurological disease or intellectual disability among the sons of female dental personnel. Our results imply that current use of dental amalgam should not represent an elevated risk for neurological disease or intellectual disability among the offspring of dental personnel.

Mortality among sons of female dental personnel--a national cohort study.

AIMS: Dental personnel are exposed to mercury when using dental amalgam. This exposure constitutes a potential hazard to offspring of women working in dentistry. The present study examined increased mortality risk in offspring of mothers working in dentistry. METHODS: Mortality was compared between sons of dental personnel and sons of nondental health-care personnel. Hazard ratios were calculated for three decades (1960s-1980s), when the magnitude of mercury exposure in dentistry was likely to have varied. RESULTS: During the 1960s, there was a statistically significant increase in the risk of neonatal mortality for sons of dental nurses when compared with sons of assistant nurses: hazard ratio (HR) 1.82 (95% confidence interval, CI: 1.04-3.22). There was no increased risk in the subsequent decades, but a trend test demonstrated a consistent decrease in the risk over the three decades: HR for trend 0.63 (95% CI: 0.44-0.90). The raised mortality risk was limited to neonatal mortality. The comparison between dentists and physicians had insufficient statistical power. CONCLUSIONS: There is no increased mortality risk among sons of female dentists after the 1960s. Although the results should be interpreted with caution, they suggest a modestly raised risk of neonatal mortality, during the 1960s, when exposure to mercury was thought to be highest.

Early struggles to identify ethical standards in dentistry: Dr. Benjamin Brown and the amalgam war of the 1840s.

Dr. Benjamin Boyer Brown was one of the leading physicians and dentists in St. Louis during the 1830s and 1840s as well as one of its most esteemed citizens for his charitable and educational works. He was also one of the founders of organized dentistry, first editor of the Dental Register of the West, as well as a respected researcher and educator in dentistry, and a member of the American Society of Dental Surgery, a forerunner of the American Dental Association. This society, declared the use of amalgam to be not only unethical but malpractice, and members were forced to sign a pledge not to use it. Although many dentists opposed this decision and ignored the pledge altogether, Dr. Brown was morally unwilling to remain quiet. He vocally opposed the decision of his colleagues to ban amalgam on ethical grounds. In spite of his appeal for reason and his high profile, he was one of the few dentists to be expelled from organized dentistry. He moved to California during the height of the gold rush to begin a new life. Dr. Brown's experience illustrates several issues in dental ethics that remain with us today.

Characterization of dental fillings found in skulls from individuals buried in San Jeronimos Church, New Spain: historical and archaeological evidences.

Repair of teeth during the XIX century was often a very costly and painful procedure. During this period, restoration of teeth was a procedure limited only to those who could afford such care. In this study we analyzed teeth from a skull sample found in San Jeronimo's Church. The characterization of molar fillings was made with techniques such as X-ray fluorescence, X-ray diffraction and electron microscopy. The purpose of this investigation was to establish technical procedures for analysis, and to discuss the results within the context of the socioeconomic status of these individuals and the written descriptions of the dental practice during the XIX century.

Amalgam: Its history and perils.

The current amalgam issue is not new. In the 1840s, there was even an "amalgam war" between the dentists who advocated the use of gold as a restorative material and those who used silver amalgam as a filling material. There were complaints of the ill effects of mercury in the amalgam as a health problem. The split on this issue threatened to divide dentistry into two camps: those who used amalgam and those who condemned it. The first national dental society in the United States, the American Society of Dental Surgeons, had to disband because of the controversy. There was even a "New Departure" movement in the 1880s to eliminate gold as a restorative material in badly broken down teeth, which could be more readily salvaged by the use of material that did not require the force of condensation needed to pack a gold foil, then considered the ultimate restorative material. However, amalgam has proven to be an excellent restorative material with few side effects--amalgam saves teeth.

Amalgama de plata: perspectiva histórica / No disponible

La amalgama de plata continúa siendo el material de restauración más ampliamente utilizado en el sector posterior de la cavidad bucal. A ello ha contribuido, entre otros factores, su fácil manipulación y su bajo coste en comparación con otros materiales alternativos. Sin embargo, el material ha sufrido profundos cambios desde sus inicios con la pasta de Taveau a mediados del siglo XIX. Las continuas mejoras introducidas en el material, en especial el elevado contenido en cobre y las evidencias de una positiva respuesta clínica, han contribuido a establecer unos parámetros normalizados que permiten garantizar, en la actualidad, un buen servicio por parte del material. Sin embargo, la controversia suscitada por el mercurio y el riesgo de la polución ambiental que generan sus desechos ha cuestionado recientemente su utilización y la búsqueda de otros materiales alternativos. En este artículo se pretende realizar un repaso breve de las principales innovaciones tecnológicas sufridas por el material desde sus inicios (AU)

Silver Amalgam is still the most common material used in posterior restorations. Contributory factors, among others, are easy manipulation and low cost in comparison with other alternative materials. However the material has suffered deep changes from its beginning with Taveau´spaste in the middle of the XIX S. The continuous improvements introduced in the material, particularly the high content in copper and the evidences of a positive clinical response have contributed to stablish normal standards that allow guarantee, at the present time, a good service of the material. However, the controversy raised by the mercury and the risk of environmental pollution that generate it´s waste has recently questioned its use and the search of other alternative materials. This article seeks to review the main technological innovations undergoneon the material from it´s beginning (AU)

A history of dental amalgam.

OBJECTIVES: Silver amalgam alloy has been used as a dental restorative material since the beginnings of restorative dentistry. It rose as an easily manipulated and low cost material in comparison to other restorative techniques of the time, but it had poor dimensional stability and clinical behavior. Successive research led to the standardization of both its composition and some aspects of its mechanical properties, which have contributed to its widespread acceptance. Nevertheless, the risk of environmental toxicity generated by mercury and its poor esthetics have given rise to the search for alternative and more promising materials. This article endeavors to give a brief historical description of the main events which have led to development of modern silver amalgam alloys. SIGNIFICANCE: It is concluded that extensive knowledge of the use of silver amalgam alloy has made it the most widely used restorative material for the posterior oral cavity. However, in recent years its preponderance has been brought into question even though some innovative ideas have been suggested which could help improve this material in the future.

[The "dental amalgam syndrome" - an environmental somatization Syndrome? A comparison between chronic carbon monoxide intoxication and illness related to dental amalgam]. / Amalgamsjukan - ett yttre miljösyndrom? En jämförelse mellan den kroniska koloxidförgiftningen (gengasförgiftningen) och amalgamsjukan.

In 1940, during World War II, restrictions in import of petroleum products to Sweden necessitated the use of producer gas in motor traffic. In the following years, the incidence of acute carbon monoxide intoxications raised steeply. However, many patients with minor but longstanding exposition to producer gas exhibited a neurastenic syndrome (fatigue, headaches and vertigo) thought to be specific. In Stockholm, an epidemic of this syndrome can afterwards be traced to the personal conviction of an internist who also had an important influence on various authorities, leading to a forceful campaign to the public about the dangers of using producer gas. After some years, the frequency and even the existence of a chronic carbon monoxide intoxication was called in question and at the end of the war that diagnosis lost its actuality. In Sweden, oral galvanism attributed to dental amalgam was discussed in mass media in the 1970s, not least by evidence given by some well-known personalities. In the 1980s, the frequency of illness attributed to dental amalgam increased to an important epidemic. The question of the dangers of mercury released from amalgam fillings is still an important issue of debate among dentists and physicians, although the majority remains sceptical. Also medical authorities have found little evidence of the importance of dental amalgam toxicity. A patients organisation, Tandvårdsskadeförbundet, seems to have played a significant part in the acceptance of the syndrome among laymen. Thus, various psychosocial factors seem to have played a role in both syndromes which could thus be conceived as environmental somatization syndromes.