Amalgam safety debate

Question 1

Anti-amalgam lobby (3)

Answer 1

Significant minority believe sincerely that the mercury in dental amalgam is responsible for a widespread disease.
Advocates for the elimination of amalgam on health grounds are a diverse group and include a small number of scientists, doctors and dentists.
The media and internet are regular providers of “scare stories” that may cause public concern or alarm.

Question 2

Dental amalgam (4)

Answer 2

Posterior restorative material (direct)
Durable, cost effective, but requires removal of tooth tissue to create retention and is not aesthetic
Approx 50% Hg by weight
-this has led to public health concerns

Question 3

Alleged symptoms of Hg poisoning due to amalgam (7)

Answer 3

Psychological
-chronic fatigue (51%)
-anxiety (31%)
-depression (28%)
Oral
-burning sensation (19%)
-metal taste (16%)
Other
-muscle pain (37%)
-headaches (27%)

Question 4

Known cliniccal symptoms of Hg poisoning (3)

Answer 4

Hg used extensively – cases of human exposure therefore widespread in history
Known symptoms of chronic exposure include nervous system (e.g. tremor, speech, etc.), gingivitis and “blue” discolouration of mucosa, renal dysfunction
Acute symptoms include GI symptoms, depression of respiration, serious kidney dysfunction, pain and death

Question 5

‘Phantom’ risk and myth of amalgam disease (4)

Answer 5

Dental amalgam contains mercury (Hg), a toxic metal.
Accumulation of relatively high concentrations of Hg in the body is associated with specific clinical symptoms.
Human exposure to Hg is inevitable (air, water, food, and amalgam restorations).
No correlation between known symptoms of diagnosed poisoning and claimed injuries or illness from anti-amalgam lobby

Question 6

Risk of adverse reaction to any dental material in the UK (4)

Answer 6

Dentists				
163 / annum / 100,000
Dental nurses		
81 / annum/ 100,000
Dental technicians	
50 / annum / 100,000
Patients				
<1 / annum / 100,000

Question 7

Adverse reaction reporting project - results (3)

Answer 7

The clinician (and his/ her team) has a greater risk of developing an adverse reaction than a patient
Exposure increases the risk associated with any one material
Adverse reactions to biomaterials are generally uncommon and not of a serious (i.e. life-threatening) nature

Question 8

Trends in the dental materials market (4)

Answer 8

Amalgam is declining in western markets, aesthetic direct restorative materials see increased use
Caries rates will continue to fall = periodontal disease will increase in significance and tooth loss will occur later in life (on average)
Patients/ society will be prepared to pay more for dental treatments in the developed/ developing world.
Poorer/ disadvantaged populations in UK and abroad have not experienced all of the benefits of the above trends, for example caries remains a serious challenge with negative consequences for individuals and societies

Question 9

Numerous studies and reviews trying to identify amalgam ‘disease’ (3)

Answer 9

Rathore et al 2012. The Dental Amalgam Toxicity Fear: A Myth or Actuality. Toxicol Int. 19(2): 81–88.
BDA “fact file”
American Dental Association 2010 review

Question 10

Minamata convention (3)

Answer 10

Named after Japanese fishing village. Mercury poisoning caused by release of methylmercury in industrial wastewater from Chisso Coporation’s chemical factory, which continued from 1932 to 1968
Led to global movement to eliminate Hg from all industrial processes including dentistry
Agreement at European level to ‘phase down’ use of amalgam, aiming for elimination by 2030

Question 11

EC regulations and impact on dental amalgam (6)

Answer 11

Dental amalgam only to be used in pre-dosed encapsulated form; use of bulk mercury by the practitioner prohibited (from 1 Jan 2019)
Mandatory use of amalgam separators (from 1 Jan 2019)
Service standards from Jan 2019: mandatory retention of at least 95% of amalgam particles for separators installed from Jan 2018, and for all separators by 1 January 2021
Dentists to ensure that their amalgam waste is handled and collected by an authorised waste management establishment
Member States to set out a national plan (by 1 July 2019) on the measures they intend to implement to phase down the use of dental amalgam.
From 1 July 2018, UK law states that dental amalgam should not be used in the treatment of deciduous teeth, inchildren under 15 years-old, and in pregnant or breastfeeding women,except when deemed strictly necessary by a dentist based on the specific medical needs of the patient.