The Following Dental Warning has been provided
for NIOAH/OSHA by the State of New Jersey!
What is Silicosis?
Silicosis is a disabling and incurable lung
disease. However, it is
preventable! Silicosis is caused by
breathing in fine dust containing crystalline
silica. Once in the lungs, this dust causes damage that stops the body from
using oxygen properly. Breathing in dust containing crystalline silica has been
linked to other diseases such as tuberculosis, kidney disease, and
lung cancer.
Silicosis begins with few, if any, symptoms. Once
present, these symptoms can include shortness of breath, severe cough, wheezing, and chest
tightness Silicosis can get worse even after exposure has stopped.
Do Dental Technicians Get Silicosis?
Yes. Silicosis has been diagnosed and confirmed in
dental laboratory workers. One individual developed the disease after only six years of
exposure.
What Tasks in a Dental Lab Cause Silica Exposure?
Casting -
Exposure can occur when mixing investment materials and during divestment of
castings. Investment materials often contain large amounts of cristobalite.
Cristobalite is a very toxic form of crystalline silica.
Sandblasting
- Sandblasting of castings can
cause exposure to the investment material or the sand itself. Silica sand is
often used to clean castings. It contains almost 100% crystalline silica.
Exposure can also occur when the blasting box has leaks. Opening the door of the
blasting box before the
dust has settled or been removed by a dust collection system is dangerous.
Grinding
porcelain - Silica content in
porcelain varies. Exposure can occur when mixing porcelain powders or when grinding or polishing dried
porcelain material.
Cleaning/Maintenance
- Tasks that involve cleaning
dusts that contain silica pose a major hazard if dust is raised. The same is
true when maintaining local exhaust ventilation or dust collection systems.
How Can Exposure to Silica be Controlled in a
Dental Lab?
Substitution
- The ideal method to stop
exposure is to eliminate materials containing crystalline silica. This method is
most feasible for sandblasting media. Aluminum oxide is one of many acceptable
substitutes.
Ventilation
- When there are no good
substitutes, dust exposure should be minimized through the use of local exhaust
ventilation systems. These systems capture dust at its source and transport it
to a dust collection system.
Respirators
- The worker should wear a
respirator when other control methods are missing or do not work. The type of
respirator recommended is, at a
minimum, a half-mask air-purifying
respirator with type N-100 particulate filters.
Good
housekeeping - Wet wiping, wet
moping, and vacuuming with a HEPA vacuum are recommended. Dry sweeping, dry
dusting, use of com-pressed air, and use of ordinary vacuum cleaners should be
avoided because they reintroduce the dust into the air.
(Elite Dental Services Comment: Use of
a Protector Workstation will eliminate the need for all of the above by
permitting all blasting or etching to be done within a totally enclosed
workstation)
What Medical Tests Should I Have If I Think That
I May Have Been Exposed to Silica?
In the case of silicosis, disease symptoms and
clinical signs are usually delayed. They may not show up for as many as 20 years
after the first exposure. If you think you have been exposed or begin to notice
symptoms such as cough and shortness of breath, you should go to your doctor and
explain your work history.
Your doctor should give you a medical exam that
checks your respiratory system. This exam should include pulmonary function tests. You will also
need a chest X-ray that should be read and evaluated by a certified
"B-reader," a person trained to read X-rays showing silicosis. A skin
test for tuberculosis is also recommended because people with silicosis are more
susceptible to this disease. Additional information can be found in the
factsheet, "To My Doctor: What
Physicians Need to Know about Occupational Silicosis and Silica Exposure Sources."
Call the Occupational Health Service or visit our web site. http://www.state.nj.us/health/eoh/survweb
.Dental
lab materials that contain silica: sand;
investment materials; porcelain; shop dust.
Can Silicosis Be Cured?
No. There is no known medical treatment to reverse
silicosis or stop its progress. This disease can only be prevented by controlling exposure to
silica dust. Workers who have been exposed to silica should stop smoking to
reduce their risk of developing lung cancer.
Are There Other Potential Health Hazards
Associated With Working in a Dental Lab?
Yes. They
include the following:
) ) Bloodborne
pathogens - Exposure to the
agents that cause HIV, Hepatitis B, and C can occur when handling impressions
and other items if contaminated with blood or saliva.
) ) Methyl
methacrylate - Used in making
dentures and plates, it can be absorbed into the body by inhalation, through the
skin, and by ingestion. It is irritating to the eyes, skin, and respiratory
tract. Repeated and prolonged exposure can cause skin sensitization and asthma,
as well as adverse effects on the nervous system.
) ) Electroplating
chemicals - The process of
electroplating can release hazardous contaminants into the air that pose a variety of risks to the
dental lab worker. The contaminants include various acid and alkaline mists that
can cause respiratory and skin problems.
) ) Metals
such as beryllium, chromium,
cobalt, and nickel. These metals in alloys used for castings of bridge framework
and other dental prosthesis components can cause a variety of lung problems.
) ) Repetitive
motion disorders - A range of
injuries to the muscles, tendons, nerves, ligaments and joints of arms, hands,
wrists, shoulders, neck, and upper back. These injuries result from damage to
the body over a period of time. If not treated they can result in chronic pain
and permanent disability.
) ) Noise
- grinding, sandblasting, and
other dental lab machinery can make noise that may cause hearing loss.
) ) Chemical
sterilants - These are used to
sterilize impressions and prosthetic devices, received from dental offices,
contaminated with blood and saliva. Sterilant chemicals include aldehydes,
phenols, and quaternary ammonium compounds. These chemicals may cause lung problems and dermatitis.
Who Can I Contact for Additional Information?
If you have any questions about silicosis or need
information about occupational health hazards in dental laboratories, please write, phone, e-mail,
or fax your request as shown below: NJ Department of Health & Senior
Services Occupational Health Surveillance Program PO Box 360 Trenton, NJ
08625-0360
Phone :
(609) 984-1863
e-mail:
surveillance@doh.state.nj.us
Fax:
(609) 292-5677
Visit our web site at
www.state.nj.us/health/eoh/survweb
Division of Epidemiology, Environmental
and Occupational Health
Clifton R. Lacy, M.D. Commissioner
James E. McGreevey Governor