December 27, 2012
Radiation alert on hand-held dental X-ray unit
Purchasing articles from e-Bay or other similar websites is cool! However, occasionally, it can become dangerous and troublesome. Recently the UK Medicines & Healthcare products Regulatory Agency (MHRA) found that a hazardous hand-held dental X-ray machine is on offer at e-Bay. Tianjie Dental ‘Falcon’ hand- held X-ray set is made in China and has very serious deficiencies.
It does not have adequate shielding in the X-ray tube. As its design is primitive, the device has substantial, non-acceptable leakage radiation.
MHRA has asked the National Health Service (NHS) and private dentists to dispose of these devices, if they have purchased them
At around 200 pounds, one can purchase the unit on auction. Safe, hand-held dental X-ray units are available; however they cost more, around 4,000 pounds each.
HPA found that under realistic work-load, operators of these unsafe units may be exposed to doses in excess of the annual limits prescribed by the regulatory body. The operators may get localised skin damage as the radiation levels at the locations where they hold the unit are very high.
Such units will expose patients to significant leakage radiation, resulting in doses almost ten times greater than it would be if the X-ray tube was adequately shielded and the X-ray beam was collimated to just the primary X-ray beam.
FIRE, SHOCK HAZARD
HPA found that the device comes with a European plug and a travel adapter that are not earthed or fused for the U.K. mains supply. Besides being a fire hazard, it could cause a fatal electric shock (50,000 volts) to the dentists or patients. “Exact numbers in use in dental surgeries in the UK are unknown, but at the present time we are aware of two dentists who bought the article.
“The UK regulator for medical devices (the Medicines and Healthcare Products Regulatory Agency, MHRA) seized 13 more units from an importer based in the West Midlands before they could be sold” Mr Andrew Gulson, DXPS Technical Manager & Radiation Protection Adviser, Centre for Radiation, Chemical and Environmental Hazards, Health Protection Agency responded to an e-mail query.
HPA first became aware of this particular model of hand-held device following an enquiry from MHRA.
“As HPA was already investigating the safety of hand held dental X-ray sets we decided to buy one ourselves from the eBay website to test as part of this project,” Mr Gulson added.
“Medical devices such as diagnostic X-ray sets used in the EU should be CE-marked to show they have been assessed to comply with the relevant EC Directives. In the U.K., it is the responsibility of the dentist to ensure X-ray equipment that they purchase meets this requirement; no further licensing or authorisation is required prior to purchase.
The case of the Tianjie Dental Falcon, which can be purchased online from a supplier based outside the EU, demonstrates that dentists who may be unaware of their responsibilities to use CE-marked equipment can nevertheless obtain it very easily and at low cost.
I understand that MHRA is working with Internet-based sellers to remove this model from their websites, but at the present time this and similar models continue to be available for purchase online in the U.K. and around the world” Mr Gulson clarified.
“Dentists who are unaware of their legal obligations are therefore most at risk of obtaining and using a device such as the Tianjie Dental Falcon with no recognition of the radiation hazard to themselves, their staff or patients,” he asserted. The full test report which Mr Gulson sent to this writer highlights the deficiencies.
As per the requirements specified by the Atomic Energy Regulatory Board, radiation generating equipment such as dental X-ray units used in India shall have “type approval” from AERB. A type approved equipment will have the prescribed built-in safety features.
Use of radiation generating equipment not approved by AERB is a violation of the legal provisions and will attract action under the appropriate provisions of the Atomic Energy Act 1962 and the relevant rules.
With the unbridled availability of such equipment, the story of X-ray comes to full circle! X-ray units in use during the first few years of the discovery of X-rays were similar.
Former Secretary, Atomic Energy Regulatory Board