By Queenter Mawinda | GUARDIAN

The Ministry of Health and Social Welfare has cautioned dentists on the use of dental amalgam saying the mercury in the chemical composition endangers human health. 

Chief Dentist Dr Ahadiel Senkoro told The Guardian on Sunday this week that dental amalgam is the source of a number of health ailments ranging from skin, lung, liver and kidney to brain, reproductive disorders and unborn infections. 

It is also a cause for gum inflammation, excessive production of saliva with a strong metallic taste and neurological symptoms that include excessive excitability and tremors in fingers, eyelids and lips  that may progress to lifetime shaking of limbs, he said. 

But even mere exposure to high doses of mercury may also produce bronchitis and pneumonia, as experienced by individuals working under poor conditions.

However, he said the harm from dental amalgam is relatively effective depending on the filling size, tooth and surface during placement, the nature of chewing and grinding, food texture, teeth brushing as well as surface area, composition and age of amalgam.

According to the Australian Dental Industry Association (ADIA), the dental amalgam contains about 50 per cent mercury and it is considered a significant source of mercury released into the atmosphere. 

He elaborated that the material that have been used to restore decayed teeth are coloured and non coloured materials. 

“The coloured ones are resin composites, compomers, glass ionomers and giomers while the non coloured one is the dental amalgam” he stated, adding that the dental amalgam that was being used in the hospital is an alloy of silver, tin , copper and mercury.

He however, admitted that there are some reported incidents of effects from dental amalgam but the medical findings could not confirm if they were caused by the mercury released from the chemical agent. 

But a woman who had her decayed teeth filled in with dental amalgam nine years ago complained of frequent loss of memory since she used the substance.
 
James Fredrick who had his teeth restored using dental amalgan five years ago has not seen any side-effects, but decried medical authorities for keeping silent over the negative effects from the widely used treatment. 

He called on the government to take urgent measures to ensure that dentists refrain from using the dangerous substance.

But Dr Senkoro defended the government, saying  it has taken considerable measures including “a shift from using elemental mercury to encapsulated amalgam” in reducing the effects. 

He said the government decided to reduce the exposure of dentists and the related personnel to mercury vapours in dental clinics and patients attending these respective clinics to the harmful medical stuff. 

According to him, in October 2013 the government signed the Minamata Convention on Mercury that calls for the phasing out of some mercury-contained items like batteries and thermometers or refrain from the use of dental amalgam. But Tanzania is yet to ratify the convention. 

The Minamata Convention on Mercury is a global treaty to protect human health and the environment from the adverse effects of mercury, and was finalised in January last year. 

Currently, 100 countries have signed the treaty, and agreed on developing and implementing national strategies to reduce or eliminate the production and industrial use of mercury, but US has formally ratified the treaty.

Dr Senkoro said mercury has been used in blood pressure measuring devices, thermometers and in some instances is used as a preservative to some vaccines.

However, he said mercury could be equally dangerous once spilled out of a device “though the quantity of mercury in these devices may be so small.” 

TFDA Public Relation Officer Gaudensia Simwanza also echoed the chief dentist’s remarks,saying the mercury in amalgam was indeed dangerous to health and hazardous to the environment. 

She said the government in line with other countries has phased out from importing the dangerous compound, but could  not dwell into medical details.

Monitoring bodies including the Tanzania Food and Drug Regulatory Authourity (TFDA), Government Chemist and Laboratory Agency are the only institutions mandated to importation mercury in Tanzania, owing to its sensitive nature.