A Nickel’s Worth
It seems that everywhere you turn these days there is someone putting out an alarm about the metals your dentist may be using as fillings, crowns, bridges, implants and/or orthodontic appliances. Usually when these kinds of alarms go out, there is some bit of information that is good for all of us to pay attention to – and one metal that falls under this category is nickel. The patients who need to pay the closest attention to this information are those who already have a recognized sensitivity or allergy to nickel; commonly something that comes to the attention after wearing nickel jewelry close to the skin.
Nickel Allergies Are Common Among Women
Although allergic reactions to dental materials are fairly rare a few studies have associated exposure to nickel with allergic reactions causing irritation to the mouth and gums. Studies also suggest that women may have a much higher incidence of allergy to nickel, and depending on what report you read, the percentage of women who are at risk ranges from 10 to 20 percent. However, over 30 percent of women under the age of 18 who participated in one research project, tested positive for nickel sensitivity. Conversely, similar studies show that up to only six percent of men are allergic, a situation that is accounted for due to their historically low contact with cosmetic jewelry at all and in particular jewelry containing nickel. There is some concern for this figure rising as more and more men use nickel jewelry as piercings.
The most common reaction to nickel is redness, swelling, and itching. Sufferers also report a strong metallic taste that just won’t go away. In dentistry the simplest solution is to replace metal crowns with all ceramic ones and once that is accomplished, allergies usually fade rather quickly – within 24 hours.
Nickel Use in Dentistry
Nickel has been used in dentistry for restorative work for well over 80 years; it is presented usually as a component of an alloy known for its strength and durability. The relatively low cost of nickel compared to other precious alloys makes it a popular choice. These nickel alloys are renowned for their ability to withstand the rather unforgiving oral environment and have a long standing history of use in dentistry as a result. It is most commonly incorporated into features including crowns, bridges, implants and removable prostheses. The amount of nickel used for any particular purpose can range from a very small percentage to up to 60 percent.
The more commonly reported instances of complication due to nickel sensitivity seem to revolve around teeth that have undergone trauma or damage to the original work, poorly fitting implants or devices, and infections in the surrounding tissue.
Nickel Toxicity in the General Population
Most studies indicate that nickel exposure in dentistry through crowns or other purposes is minimal, and that people suffering the more adverse reactions have an existing allergy or sensitivity to the metal. However, it may be helpful if not informative to realize that people who have been exposed to nickel occupationally are at the highest risk of developing serious health issues and complications.
Nickel has been recognized for decades as a carcinogen. Back in 1932 workers in a nickel refinery in Wales developed the first documented cases of respiratory tract cancers directly related to nickel exposure, or overexposure as the case may be (nickel sulfide and nickel oxide specifically). People living adjacent to the refinery also developed sensitivity to nickel, presenting the earliest cases of skin irritations and eczema, the same symptoms showing up today most commonly among women who frequently wear jewelry or piercings made of nickel.
The Health Risks of Overexposure
Of itself nickel is an insidious contributor to a wide range of illnesses in people who are unfortunate enough to be overexposed to its chemical components. It is known to weaken the immune system and generally complicate problems associated with heavy metal build-up in the body, particularly; hormonally and by contributing to immune and nervous system disorders, as well as interfering in the body’s natural detoxification and metabolic processes.
Nickel can negatively impact the body’s absorption of which can lead to immune defects such as allergies and a generally reduced resistance to disease. An increased level of nickel in the bloodstream can be a warning of immunologic problems or point to an increased risk of cardiovascular diseases.
Experiments on animals exposed to large amounts of nickel have demonstrated reduced cerebral activity as well as defects in many major organs such as the heart, liver, lungs and kidneys. These studies have confirmed that air contaminated by nickel dust can cause lung cancer. Nickel can also increase the content of fat in the blood, it can weaken the effect of adrenaline, and it can increase the effect of insulin.
In men, it is reported that prostate tissue tends to amass nickel, as apparently the prostate collects toxins and is particularly susceptible to nickel. In this circumstance bacteria seem to thrive on an environment rich in nickel and as a result urinary tract bacteria bolstered by toxins such as nickel consistently cause prostatitis and urinary tract infections.
Talk to Your Doctor
If you are concerned about possible reactions from the use of nickel-containing devices talk to your dentist prior to undergoing any procedure or restoration. Have your dentist confirm with the manufacturer of any device to be implanted that the item is free of nickel prior to usage. Your dentist can provide all the information needed to help you make treatment decisions that are in your best interests.