RISK OF HIV: HOW SAFE IS YOUR DENTIST??

HIV (human immunodeficiency virus) is the virus that causes AIDS. This virus is passed from one person to another through blood-to-blood contact (blood transfusions, HIV-infected needles) and sexual contact. In addition, an infected pregnant woman can pass HIV to her baby during pregnancy or delivery, as well as through breast-feeding.

AIDS (acquired immunodeficiency syndrome) occurs when the HIV infection has weakened one's immune system to the point that it has difficulty fighting off certain illnesses and infections. "Opportunistic" infections also occur, taking the opportunity a weakened immune system gives to cause illness.

A positive HIV test result does not mean that you have AIDS. AIDS is a medical diagnosis made by a doctor based on specific criteria. You also cannot rely on symptoms to know whether or not you are infected with HIV. Many people who are infected with HIV do not have any symptoms at all for many years.

The warning signs of infection with HIV are rapid weight loss, dry cough, recurring fever or profuse night sweats, profound and unexplained fatigue, swollen lymph glands in the armpits, groin or neck, diarrhea that lasts for more than a week, white spots or unusual blemishes on the tongue, in the mouth or in the throat, pneumonia, red, brown, pink or purplish blotches on or under the skin or inside the mouth, nose or eyelids, memory loss, depression and other neurological disorders.

Dental problems such as sore bleeding gums, herpes sores in the mouth, and fungal and candida (yeast) infections may be among the first signs of AIDS. However, you should not assume you are infected if you have any of these symptoms as these occur in the general population as well. The only way to determine whether you are infected is to be tested for HIV infection.

Due to the nature of dental treatment, HIV may be transmitted during the course of dental treatment. Universal precautions have to be used between each and every patient to prevent the transmission of HIV and other infectious diseases.

These precautions require dentists, dental hygienists and dental assistants to wear gloves, facemasks and eye protection, and to sterilize all handpieces (drills) and other dental instruments for every patient, using specific sterilization procedures outlined by the CDC (Center for Disease Control). Items that cannot be sterilized are to be discarded in special containers. After each patient visit, gloves have to be discarded, hands are washed and a new pair of gloves used for the next patient.

Laboratory studies have found that when traces of blood become embedded in dental handpieces, germicidal chemicals cannot kill even the weakest human pathogens, such as HIV. Studies were conducted using trace quantities of whole blood (100 microliters) from HIV-infected patients. The AIDS virus remained infectious for at least two days, but less than one week, when trapped in dental handpieces, even when treated with the recommended 2 percent solution of glutaraldehyde (one of the more powerful chemical germicides).

A study was published by the American Society for Microbiology in 1992 which stated that dental handpieces could potentially transmit HIV and other infectious agents. It recommended the adoption of a heat sterilization standard (autoclaving, chemclaving or dry heat) to kill viruses lodged in dental handpieces.

The dental patients simply “tell their dentists `goodbye` and walk out the door” after their treatment. If they later become sick with hepatitis, pneumonia, or even AIDS, there is no way to document whether or not the disease originated with a dental device, because no such records are kept. Also, the long incubation period of HIV makes tracking especially problematic, and legal barriers prevent disclosure of patient identities.

Use of high-speed dental handpieces provide two potential routes of infection, which occur primarily when patients are exposed to the air/water spray expelled by dental handpieces as the devices are operated inside the mouth: waterborne pathogens and bloodborne pathogens.

With waterborne pathogens, patient blood and saliva retracted into water lines inside handpieces can travel all the way back into the flexible lines that feed water into the handpieces. Therefore, before re-attaching water lines to handpieces after the handpieces have been removed and sterilized, it is recommended that dentists flush them for a couple of minutes. This washes out patient materials that may have been retracted into the lines, leaving behind only those organisms (mostly bacteria) that can cling to the inside walls of lines. These microorganisms multiply in “biofilms” or layers that can shed microbes back out during operation of the equipment, presenting the risk of pneumonia and other diseases, especially high to immunocompromised patients.

With bloodborne pathogens, traces of blood withdrawn into airways of handpieces remain largely undiluted with water and become embedded inside the handpiece or in air lines that exhaust away from the patient. This potentially infectious material, mixed with lubricants inside the devices, is impervious to germicides and presents a potential risk of infections such as HIV and hepatitis. Heat sterilization after each patient use can virtually eliminate the risk of transmitting bloodborne infections patient-to-patient, a risk shared by all dental patients if handpieces are merely treated with chemical germicides.

Almost any type of infectious disease, from the common cold to the AIDS virus, could potentially be transmitted by contaminated lubricants expelled by dental and medical devices. Patients at highest risk are those with damaged immune systems, such as the elderly, individuals undergoing chemotherapy, organ transplant recipients, and AIDS patients. However, of more concern in this country are the more easily transmitted diseases carried by a large portion of the population such as influenza, cytomegalovirus and infectious hepatitis. HIV is probably rarely transmitted by contaminated dental handpieces. So far, dental HIV transmission through this route is rare. However, in areas of the world where a high proportion of the population is HIV-infected and where old and worn dental devices are commonly used without heat-sterilizing them, patient-to-patient HIV transmission in dentistry may occur more frequently.

Recently updated guidelines recommend heat sterilization, or autoclaving, of dental devices. However, only 40 to 80 percent of dentists actually autoclave their instruments as they should. CDC published upgraded guidelines for dentistry in 1993, recommending the exclusive use of heat sterilization processes “for all reused devices entering the oral cavity.”

Some dentists consider wiping handpieces with chemical solutions to be a form of sterilization. Others just are not completely truthful with patients about their infection control practices. Patients should look for gloves being changed after every patient and sterilized instruments opened after the patient is seated. They should also ensure that the dentists as well as the staff members are wearing protective gear such as masks, gloves and eye protection. They should feel free to ask questions about sterilization procedures being observed in the dental clinic. One’s safety, after all, is in one’s own hands.