INFECTION CONTROL

 What is the purpose of personal protective equipment (PPE)?

PPE is designed to protect the skin and the mucous membranes of the eyes, nose, and mouth of dental health-care personnel from exposure to blood or other potentially infectious material. A visible spray is created during the use of rotary dental and surgical instruments (e.g., handpieces, ultrasonic scalers) and air-water syringes. This spray primarily consists of a large-particle spatter of water, saliva, blood, microorganisms, and other debris. Spatter travels only a short distance and settles out quickly, landing either on the floor, nearby equipment and operatory surfaces, dental health-care personnel, or the patient. The spray may also contain some aerosol (i.e., particles of respirable size: 10 microns). Aerosols take considerable energy to generate and are not typically visible to the naked eye. Aerosols can remain airborne for extended periods and can be inhaled. However, they should not be confused with the large-particle spatter that makes up the bulk of the spray from handpieces and ultrasonic scalers. Appropriate work practices such as the use of dental dams and high-velocity air evacuation should minimize droplets, spatter, and aerosols. OSHA mandates that dental health care workers wear gloves, surgical masks, protective eyewear, and protective clothing in specified circumstances to reduce the risk of exposures to bloodborne pathogens.

When should a surgical mask be worn?

Dental health-care personnel should wear a surgical mask that covers both their nose and mouth during procedures and patient-care activities that are likely to generate splashes or sprays of blood or body fluids. A surgical mask protects the patient against microorganisms generated by the wearer and also protects dental health care personnel from large-particle droplet spatter that may contain bloodborne pathogens or other infectious microorganisms. When a surgical mask is used, it should be changed between patients or during patient treatment if it becomes wet.

When should protective eyewear be worn?

Dental health care personnel should wear protective eyewear with solid side shields or a face shield during procedures and patient-care activities likely to generate splashes or sprays of blood or body fluids. Protective eyewear protects the mucous membranes of the eyes from contact with microorganisms. Protective eyewear for patients also can protect their eyes from spatter or debris generated during dental procedures. Reusable protective eyewear should be cleaned with soap and water, and when visibly soiled, disinfected between patients.

When should protective clothing be worn?

Various types of protective clothing (e.g., gowns, jackets) are worn to prevent contamination of street clothing and to protect the skin of personnel from exposure to blood and body fluids. When the gown is worn as personal protective equipment (i.e., when spatter and spray of blood, saliva, or other potentially infectious material is anticipated), the sleeves should be long enough to protect the forearms. Protective clothing should be changed daily or sooner if visibly soiled. Personnel should remove protective clothing before leaving the work area.

Why should dental health care personnel wear gloves?

Dental health care personnel wear gloves to prevent contamination of their hands when touching mucous membranes, blood, saliva, or other potentially infectious materials and to reduce the likelihood that microorganisms on their hands will be transmitted to patients during dental patient-care procedures.

Does wearing gloves replace the need for handwashing?

Wearing gloves does not replace the need for handwashing. Personnel should wash their hands immediately before donning gloves. Gloves may have small, unapparent defects or may be torn during use, and hands can become contaminated during removal of gloves. In addition, bacteria can multiply rapidly in moist environments underneath gloves; thus, personnel should dry their hands thoroughly before donning gloves and wash immediately after removing the gloves. If the integrity of a glove is compromised (e.g., if the glove is punctured), the glove should be changed as soon as possible.

Is it safe to wash gloves before use?

Washing of latex gloves with plain soap, chlorhexidine, or alcohol can cause micropunctures. This condition, known as "wicking," may allow liquids to penetrate through undetected holes in the gloves. For that reason, washing of gloves is not recommended.

Are gloves affected by dental materials?

Exposure to glutaraldehyde, hydrogen peroxide, and alcohol preparations may weaken latex, vinyl, nitrile, and other synthetic glove materials. Other chemicals associated with dental materials that may weaken gloves include acrylic monomer, chloroform, orange solvent, eugenol, cavity varnish, acid etch, and dimethacrylates. Because of the diverse selection of dental materials on the market, glove users should consult glove manufacturer about the compatibility of glove material with various chemicals.

Are there different types of gloves?

Yes, there are. The type of glove used should be based upon the type of procedure to be performed (e.g., surgical vs. nonsurgical, housekeeping procedures). Medical-grade nonsterile examination gloves and sterile surgical gloves are medical devices regulated by the U.S. Food and Drug Administration (FDA). General-purpose utility gloves are not regulated by the FDA because they are not promoted for medical use. Sterile surgical gloves must meet standards for sterility assurance established by the FDA and are less likely than nonsterile examination gloves to harbor pathogens that may contaminate an operative wound.

Glove Type Indications Comments Common Glove Materials
Patient examination gloves Examinations and other nonsurgical procedures involving contact with mucous membranes; laboratory procedures Medical device regulated by the FDA.
Nonsterile and sterile, single-use disposable. Use for one patient and discard appropriately.

People infected with viruses such as HIV, hepatitis B and hepatitis C may not have symptoms for many years, so it is possible patients might have been infected and not know it. Even though patients who may have been exposed may not feel ill or remember getting sick, they should get tested. Although testing cannot determine where or how someone was infected (at Stein’s offices or from another exposure), it is important to know so treatment can begin.
Health providers who test Stein’s former patients are being asked to report any tests positive for HIV, hepatitis B or hepatitis C to their county health department or the state health department and to specify the patient was tested as a result of unsafe injection practices at Stein Oral and Facial Surgery. HIV, hepatitis B and hepatitis C are reportable conditions in Colorado, meaning they must be reported to public health authorities.
Needed Tests
Patients who may have been exposed should ask their health provider to order the following tests:
HIV antibody
If positive, reflex confirmatory testing with Western blot or other approved confirmatory methods should be performed.
Hepatitis C antibody
If positive, hepatitis C RNA (quantitative or qualitative) should be performed. (Reflex testing often is available for hepatitis C RNA.)
Hepatitis B surface antigen and hepatitis B core antibody should be done. Hepatitis B surface antibody also should be considered and is useful to determine immunity to hepatitis B.

One in nine dentists inspected by the health care watchdog were found to be in breach of strict guidelines on cleanliness and infection control designed to prevent the spread of conditions such as HIV, hepatitis and vCJD.
Under Freedom of Information laws, The Daily Telegraph obtained a copy of a database detailing the results of inspections by the Care Quality Commission (CQC), the healthcare regulator.
An analysis reveals that of the 1,667 dental practices inspected by the CQC last year, 189 were found to not be following Department of Health instructions on how to clean instruments and surgeries. Some 8,100 dentists are registered in England.
In order to prevent the spread of blood-borne disease, experts recommend instruments are prepared in a separate room to the dentist’s surgery. They should be scrubbed in one sink, rinsed in a second, inspected for any fragments under an microscope and processed through an ultrasonic bath or an autoclave steam cleaner.
They must then be stored for up to three weeks in sterile and dated packets.Some equipment cannot be cleaned and re-used safely and most be thrown away after each patient.
But dozens are practices are disregarding the rules, inspectors found.
At one “cluttered and dirty” practice in Haringey, North London, inspectors in February found staff could not tell the difference between single-use and re-usable equipment, and they “could not be sure” that equipment in drawers ready for use in surgery had been cleaned.
Inspectors found an opened intravenous needle kit and out-of-date medicine stored in a fridge alongside the staff’s packed lunches, while used gloves and tissues, and a packet of porridge oats, were stored on top of the sterilisation machine.
The practice has since been given a clean bill of health.
At Lydiate Dental Surgery, Merseyside, the autoclave used for sterilizing equipment was found to be “unclean, felt ‘oily’ and had debris on it”, inspectors wrote. They found dust, dirt and cobwebs and overflowing bins in the surgery.
A spokesman said the surgery was “very concerned” by the report and had “reviewed arrangements” as a result.
Inspectors found staff at Wilton Dental Practice, Wiltshire, attempting to sterilize and re-use equipment that was single-use only.The practice did not respond to requests for comment.
At ADP Dental Company’s branch in Bath, staff told inspectors that broken ultrasonic equipment meant they “could not clean the equipment quickly enough”. They admitted they did not use a magnifying light to check whether instruments were clean, and sometimes “did not bother” to wash their hands.
Inspectors warned: “People may not be fully protected against the risks of cross infection.”
A spokesman said: “The issues highlighted have been immediately addressed and rectified to the correct standards.
“We have also delivered additional training and checking mechanisms since the report was published to ensure we maintain the highest standards for all our patients."
The risk of patients catching blood-borne infections through inadequately sterilised equipment is low but not without precedent. In 2009 5,000 patients in Bristol and Bournemouth were offered blood tests for HIV and hepatitis after a dentist was found to have not sterilised equipment properly.
Katherine Murphy, chief executive of the charity The Patient’s Association, said: “Infection control practices in dentistry must be given the highest priority. All too often patients tell our helpline that they have concerns about cleanliness.”
Dr Martin Fallowfield, chair of the British Dental Association’s executive committee, which represents dentists, said earlier studies had shown around one in 17 practices were in breach of infection control rules. He added the sector had a better track record of infection control than that found in nursing homes and NHS hospitals.

In the study, researchers from the pediatric dentistry department at the University of Nevada, Las Vegas (UNLV) School of Dental Medicine found that using the Isolite system or a dental dam with high-volume evacuation (HVE) resulted in significantly less spatter than using HVE alone (Journal of the American Dental Association, November 2012, Vol. 143:11, pp. 1199-1204).

Hard-tissue preparation with handpieces and ultrasonic scalers results mostly in large-particle spatter, which settles on surrounding surfaces, the study authors noted. This can result in contamination issues with transmissible forms of tuberculosis, influenza, Legionnaires’ disease, and severe acute respiratory syndrome. The effectiveness of dental dams has been established by previous research, while other studies found that an HVE is able to limit the amount of aerosol and spatter emanating from a dental procedural site by 90%.

“We wanted to compare the effectiveness of two dry-field isolation techniques with a control (no isolation) in reducing spatter from a dental operative site,” Richard Walker, DDS, a professor of clinical sciences at UNLV’s School of Dental Medicine who participated in the study wrote in an email to DrBicuspid. ” The results of the study showed that use of a dental dam and HVE or with the Isolite system significantly reduced spatter overall compared with use of HVE alone.”

Documenting spatter pattern

To prepare for the benchtop experiment, the researchers covered vents in the operatory so that they did not impact the spatter pattern. A typodont manikin head was situated in the headrest of a dental chair and the oral cavity surrounded by a 4 x 3-inch platform covered with paper. Next, they used clamps to secure an HVE and a high-speed dental handpiece (INTRAmatic Lux 3 25LHA, KaVo Dental) in the manikin’s mouth, simulating the position of a right-handed dentist who is preparing three posterior teeth.

The handpiece’s water flow was set at 25 mL per minute. During both the first experimental and control trials, the orifice of the HVE was placed 1 cm from the tooth undergoing preparation.

Preparation was simulated on teeth Nos. 18, 19, and 20 in all three procedures, eight times each, for a total of 72 trials (effect size = 0.20; p < 0.05). A bite block and the HVE were in place during control testing. In the first experimental setting, teeth were prepared with a bite block, dental dam, and the HVE in place. For the second experimental setting, an Isolite system was placed in the manikin's mouth and set at maximum strength. The water used in the study was blended with dye for easier viewing, and after each trial the researchers removed and examined the paper covering the surface of the wooden platform. They gridded the paper and examined it for signs of spatter. One or more spots found within a 5-cm2 grid square qualified that particular square on the paper as contaminated. They then tallied the number of contaminated squares per trial and analyzed the results. Limiting contamination The researchers found, overall, no statistically significant difference between the two dry-field techniques in the amount of spatter reduction. They also found that the two techniques were similarly effective when performing procedures where mandibular posterior permanent teeth were involved. However, they found significantly more spatter reduction using a dental dam and HVE than with the Isolite system when they prepared tooth No. 20 with each technique in their trials, compared with Nos. 18 and 19. "The two-way ANOVA [analysis of variance] showed statistically significant differences in the amount of spatter produced between the control, dental dam, and Isolite groups (p < 0.001), in the amount of spatter produced between teeth numbers 18, 19, and 20 (p < 0.003), and in the interaction between the isolation method and the tooth number (p < 0.001)," the researchers wrote. They also noted significantly less spatter in the experimental trials and no statistical significant difference between isolation methods. The researchers observed some disparities in the performance of each spatter-control method on each tooth. On 18, the experimental methods equally outperformed the control. On 19, spatter reduction with the dental dam was significant but not when the Isolite system was used (p < 0.056). "Yet, there was no significant difference between the dental dam and the Isolite device for tooth number 19," the study authors wrote. For tooth 20, there was a statistically significant reduction in spatter for both experimental methods, but there was significantly more reduction with the dental dam than with the Isolite device (p < 0.001). The researchers attributed the better performance of the dental dam and HVE over the Isolite system in this situation to the design of the latter. Gingival tissue exposed The researchers noted the Isolite system's myriad features, such as isolation, high-speed evacuation, and protection of adjacent soft tissues, and ease of use in their report. The system also enables procedures that may be hindered by access problems presented by a dental dam. But they also observed that the Isolite leaves some of the gingival tissue exposed while a dental dam is inverted into the gingival sulcus. "The bacterial content of the aerosol and spatter produced when using the Isolite device may be higher or more diverse than that produced when using the dental dam with HVE," they wrote. "This study focused on the amount of spatter, not the amount of pathogens in the spatter," Dr. Walker noted. "Therefore, no conclusions can be made concerning the amount of microbial contamination between the different methods. Our in vitro set-up showed that the two dry field isolation techniques reduced the amount of spatter compared to the control (no isolation). Further in vivo study measuring microbial contamination will be necessary to determine the potential for reduction of communicable disease transmission." The researchers acknowledged Isolite Systems as a financial supporter of the study.