Evironmental impact of direct dental restorative materials :amalgam versus resin composite

Question 1

Describe the Minamata convention on mercury (2013) .

Answer 1

• Environmentally driven
• Global phase down (was out) of dental amalgam
• Estimated 270 – 341 metric tonnes Hg globally derived from dental amalgam use. : This equates to approx. 20% of global mercury consumption for products

Question 2

what is use of dental amalgam no longer allowed for?

Answer 2

• children under 15 years old
• pregnant women
• breastfeeding women
• EXCEPT when deemed strictly necessary by the dental practitioner based on the specific medical needs of the patient

Question 3

what is the Scottish dental clinical effective program guidance on dental amalgam?

Answer 3

restrictions aim to help reduce environmental mercury pollution and are not as a result of any safety concerns about amalgam fillings for dental patients
Dental amalgam is the only suitable material despite the environmental concerns and so the dentist may advice amalgam filling

Question 4

what is mercury released from?

Answer 4

• Natural events – Volcanic eruptions
• Anthropogenic – industrial processes, coal combustion, dental treatment
• And accumulates as sediment finding way into water ways

Question 5

why do we need to protect environment by reducing mercury use?

Answer 5

Methylate Hg into methylmercury:
• Highly toxic
• Gives access to food web for use by low order organisms
• Scope for biomagnification in predatory long‐lived fish e.g. Tuna that consumed by Humans

Question 6

Name potential environmental pollution routes.

Answer 6

• Atmosphere and Water from dental practices
• Internment/Cremation of bodies with amalgam restorations
• Chewing/masticationoffoods

Question 7

How are these routes reduced?

Answer 7

• These may be reduced by:

• Dental Unit traps & amalgam separators
• Safe and regulated disposal of waste amalgam
• Incorporation of Selenium filters into chimneys of crematoria.

Question 8

Discuss environmental costs of burial.

Answer 8

89% of coffins are chipboard veneer
• Contains formaldehyde that also used in embalming
• Leaches out into groundwater
• Energy required to make or alternatively may be consumed if using a concrete vault.

Question 9

Discuss environmental costs of cremation.

Answer 9

• Energy – 285 KWh gas and 15 KWh electricity
• Generates Carbon Dioxide equivalent to a car journey of 800 Kilometers
• Approximately 16% of mercury in the air is from dental amalgams

Question 10

Discuss potential environmental pollution concerns of resin composite.

Answer 10

Bisphenol A:
• Mimics oestrogen (said to be at concentration of no risk in composites)
• Currently a small contributor to overall environmental pollution.

Question 11

how do resin composites enter the environment?

Answer 11

• Manufacture
• Burial of those with composite restorations
• Disposal of out of date materials from dental practice that end up in landfill
• ALSO consider at placement microparticulate/microplastic pollution cf. Shower gel beads : enter food chain, ingested by fish and eaten by humans.

Question 12

Name potential effects of bisphenol A.

Answer 12

• Genital tract abnormality
• Childhood obesity
• Infertility
• Increased incidence of breast cancer