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OSHA
Preambles - Bloodborne Pathogens
(29 CFR 1910.1030)Revision
Date: Jul 30 1999
Most healthcare
workers who have transmitted to patients have several
factors in common (Exs. 6-476; 6-471):
(1) The dentists and surgeons were chronic HBV carriers,
had high titers of virus in their blood (HBeAg
positive), and were unaware that they were
infected.
(2) Transmission occurred most frequently during the
most traumatic procedures.
(3) The dental personnel who transmitted did not
routinely wear gloves. However, some infected HCWs
continued to transmit HBV to patients in spite of
the use of gloves and additional precautions.
(4) The dentists and surgeons often had a personal
medical problem (such as exudative dermatitis on
the hands), or used techniques that made transmission
more likely. Several of the gynecologists used their
index fingers to feel for the tip of the suture
needle when they were performing deep abdominal
surgery.
Failure
of gloves and other protective devices to prevent
transmission of hepatitis B virus to oral surgeons.
JAMA 1988 May 6;259(17):2558-60 Reingold AL, Kane
MA, Hightower AW Department of Biomedical and
Environmental Health Sciences, School of Public Health,
University of California, Berkeley.
A survey of 434 oral surgeons was conducted to
examine risk factors for hepatitis B virus (HBV)
infection. Overall, 112 (26%)
of the participants demonstrated serologic evidence of
past or current infection with HBV. Seropositivity was
significantly associated with age, number of years in
practice, and year of graduation from dental school but
not with other variables examined, such as the number of
patients seen annually or the number of patients seen
who were at high risk of HBV infection. The strong
correlation between years in practice and seropositivity
was unaffected by reported use of gloves, face masks, or
eye shields. The use of gloves and other protective
devices does not appear to offer substantial protection
against HBV exposure in oral surgeons, and all oral
surgeons should receive HBV vaccine. PMID: 3357229, UI:
88188297
Veterans
Administration cooperative study on hepatitis and
dentistry.
Am
Dent Assoc 1986 Sep;113(3):390-6 Schiff ER, de Medina
MD, Kline SN, Johnson GR, Chan YK, Shorey J, Calhoun N,
Irish EF
Personnel in the VA dental facilities were screened for
the detection of viral hepatitis and identification of
factors implicating infectivity. A total of 963
personnel from 126 dental facilities throughout the
United States voluntarily participated in the study. The
rate of seroconversion for any hepatitis B markers was
approximately 1% per year. Serial positive tests for
antibody to hepatitis B core antigen or antibody to
hepatitis B surface antigen (or both) were present in
16.2% of dentists and 13.0% of dental auxiliary
personnel. Oral and maxillofacial
surgeons composed the highest prevalence occupation
(24.0%), and clinical
personnel composed the lowest prevalence occupation
(8.9%). There was a significant association between
years in dental environment and serological positivity
for viral B infection. The dentists and dental auxiliary
personnel had significant linear trends of increasing
serological positivity with years in the dental
environment. Although a majority of personnel reported
wearing gloves while treating high-risk patients or
performing invasive procedures, inadequate prophylactic
measures were exercised for most patients undergoing a
variety of less invasive procedures. The results of the
study show the need for an active immunization program
against type B viral infection for dental and dental
auxiliary personnel, preferably before the initial
exposure to the professional environment. PMID: 3531282,
UI: 87009463
PHILADELPHIA
INQUIRER AIDS VIRUS SURVIVES DENTAL-TOOL WASH HEAT
STERILIZATION IS URGED. A STUDY FOUND WASHINGTHE TOOLS
WITH DISINFECTANT DIDN'T DO THE JOB. Published
on 11/21/1992,
TEXT:
The viruses that cause AIDS and hepatitis B can survive
within dental tools that are washed with disinfectant
but not heat-sterilized, posing a potential risk of
disease transmission, according to a new study.
The recent case
of a Florida dentist who transmitted the virus to five
patients ignited widespread fear about catching AIDS
from dental procedures. But the infected patients in
Florida got the virus from the dentist, not from
contaminated equipment, according to investigations
Viral hepatitis as an occupational hazard of dentists.
J Am Dent Assoc 1975 May;90(5):992-7
Mosley JW, White E
To estimate the
risk of viral hepatitis for practicing dentists, a
questionnaire survey was conducted in the greater Los
Angeles area among the part-time faculty of the
University of Southern California School of Dentistry.
An icteric episode diagnosed as hepatitis had been
experienced by 11, representing 3.9% of the 285 dentists
to whom questionnaires were mailed or 4.5% of the 242
respondents. All illnesses occurred after graduation
from dental school, and five were after 1967. For
general dentists, the minimal frequency was 2.7 (5 of
187 in the sample). Specialists with emphasis in
surgical forms of dentistry had hepatitis with a
significantly higher frequency: 3 of 19 oral surgeons; 1
of 13 periodontists; and 1 of 9 endodontists. The risk
did not vary in this sample with the proportion of young
adult patients (15 to 29 years of age) in the practice
or recognizable illicit self-injection among patients.
Auxiliary dental personnel seem to have a lower risk
than dentists themselves. Measures to reduce the hazard
are indicated, but at present these are confined to
greater care in avoiding percutaneous introduction. PMID:
123933, UI: 75152152
Hepatitis B and dental personnel: transmission to patients
and prevention issues.
J Am Dent Assoc 1983 Feb;106(2):219-22Ahtone J, Goodman RA
Hepatitis B virus (HBV) infection is considered an
occupational risk for dental professionals. The Centers
for Disease Control have participated in eight
investigations regarding dental professionals who were
suspected of transmitting HBV infection to their
patients. This article summarizes the findings of the
investigations, the postulated mechanism of transmission
of HBV, control measures suggested, and follow-up of the
dental practice for those dentists who were chronic
carriers of hepatitis B surface antigen. The approach by
the centers for managing dental professionals who are
HBsAg positive and those dental professionals who are
HBsAg positive and implicated as transmitting HBV
infection to patients are outlined. If HBV transmission
cannot be interrupted, by suggested measures, then more
restrictive measures should be decided on by state or
local health officials, or both. These could include removal
of the practitioner's license. HBV-infected dental
personnel can transmit HBV infection to their patients.
The measures suggested for the HBV carrier are designed
to allow the dental practitioner to continue practice,
but, at the same time, give maximum protection to the
patient. PMID: 6572677, UI: 83162024
Cross-contamination potential with dental equipment.
Lancet. 1992 Nov 21;340(8830):1 252-4.
PMID: 1359320; UI: 93061644.
Prevention of infection in dental procedures.
J Hosp Infect. 1997 Jan;35(1):17-25.
PMID: 9032632; UI: 97184863.
Microbiological
evaluation of a newly designed dental air-turbine
handpiece for anti-cross contaminations.
Int J Prosthodont. 1994 May-Jun;7(3):201-8.
PMID: 7916884; UI: 95000158.
Prevention
of microbial contamination of the dental unit caused by
suction into the turbine drive air lines.
Oral Surg Oral Med Oral Pathol Oral Radiol
Endod. 1996 Jan;81(1):50-2.
PMID: 8850483; UI: 97003144.
Bacterial
adherence and contamination during radiographic
processing.
Oral Surg Oral Med Oral Pathol. 1990
Nov;70(5):669-73.
PMID: 2122350; UI: 91044263.
Prevention of bacterial contamination of water in dental
units.
J Hosp Infect. 1985 Mar;6(1):81-8.
PMID: 2859327; UI: 85183881.
May 28, 1993 / 42(RR-8) Recommended Infection-Control
Practices for Dentistry, 1993 Summary
This
document updates previously published CDC
recommendations for infection-control practices in
dentistry to reflect new data, materials, technology,
and equipment. When implemented, these recommendations
should reduce the risk of disease transmission in the
dental environment, from patient to dental health-care
worker (DHCW), from DHCW to patient, and from patient to
patient. Based on principles of infection control, the
document delineates specific recommendations related to
vaccination of DHCWs; protective attire and barrier
techniques; handwashing and care of hands; the use and
care of sharp instruments and needles; sterilization or
disinfection of instruments; cleaning and disinfection
of the dental unit and environmental surfaces;
disinfection and the dental laboratory; use and care of
handpieces, antiretraction valves, and other intraoral
dental devices attached to air and water lines of dental
units; single-use disposable instruments; the handling
of biopsy specimens; use of extracted teeth in dental
educational settings; disposal of waste materials; and
implementation of recommendations.
INTRODUCTION
This
document updates previously published CDC
recommendations for infection-control practices for
dentistry (1-3) and offers guidance for reducing the
risks of disease transmission among dental health-care
workers (DHCWs) and their patients. Although the
principles of infection control remain unchanged, new
technologies, materials, equipment, and data require
continuous evaluation of current infection-control
practices. The unique nature of most dental procedures,
instrumentation, and patient-care settings also may
require specific strategies directed to the prevention
of transmission of pathogens among DHCWs and their
patients. Recommended infection-control practices are
applicable to all settings in which dental treatment is
provided. These recommended practices should be observed
in addition to the practices and procedures for worker
protection required by the Occupational Safety and
Health Administration (OSHA) final rule on Occupational
Exposure to Bloodborne Pathogens (29 CFR 1910.1030),
which was published in the Federal Register on December
6, 1991 (4).
Dental
patients and DHCWs may be exposed to a variety of
microorganisms via blood or oral or respiratory
secretions. These microorganisms may include
cytomegalovirus, hepatitis B virus (HBV), hepatitis C
virus (Hepatitis C Virus), herpes simplex virus types 1 and 2, human
immunodeficiency virus (HIV), Mycobacterium
tuberculosis, staphylococci, streptococci, and other
viruses and bacteria -- specifically, those that infect
the upper respiratory tract. Infections may be
transmitted in the dental operatory through several
routes, including direct contact with blood, oral
fluids, or other secretions; indirect contact with
contaminated instruments, operatory equipment, or
environmental surfaces; or contact with airborne
contaminants present in either droplet spatter or
aerosols of oral and respiratory fluids. Infection via
any of these routes requires that all three of the
following conditions be present (commonly referred to as
"the chain of infection"): a susceptible host;
a pathogen with sufficient infectivity and numbers to
cause infection; and a portal through which the pathogen
may enter the host. Effective infection-control
strategies are intended to break one or more of these
"links" in the chain, thereby preventing
infection.
A
set of infection-control strategies common to all
health-care delivery settings should reduce the risk of
transmission of infectious diseases caused by bloodborne
pathogens such as HBV and HIV (2,5-10). Because all
infected patients cannot be identified by medical
history, physical examination, or laboratory tests, CDC
recommends that blood and body fluid precautions be used
consistently for all patients (2,5 ). This extension of
blood and body fluid precautions, referred to as
"universal precautions," must be observed
routinely in the care of all dental patients (2). In
addition, specific actions have been recommended to
reduce the risk of tuberculosis transmission in dental
and other ambulatory health-care facilities (11).
CONFIRMED
TRANSMISSION OF HBV AND HIV IN DENTISTRY
Although
the possibility of transmission of bloodborne infections
from DHCWs to patients is considered to be small (12-
15), precise risks have not been quantified in the
dental setting by carefully designed epidemiologic
studies. Reports published from 1970 through 1987
indicate nine clusters in which patients were infected
with HBV associated with treatment by an infected DHCW
(16-25). In addition, transmission of HIV to six
patients of a dentist with acquired immunodeficiency
syndrome has been reported (26,27). Transmission of HBV
from dentists to patients has not been reported since
1987, possibly reflecting such factors as incomplete
ascertainment and reporting, increased adherence to
universal precautions -- including routine glove use by
dentists -- and increased levels of immunity due to use
of hepatitis B vaccine. However, isolated sporadic cases
of infection are more difficult to link with a
health-care worker than are outbreaks involving multiple
patients. For both HBV and HIV, the precise event or
events resulting in transmission of infection in the
dental setting have not been determined; epidemiologic
and laboratory data indicate that these infections
probably were transmitted from the DHCWs to patients,
rather than from one patient to another (26,28).
Patient-to-patient transmission of bloodborne pathogens
has been reported, however, in several medical settings
(29-31).
VACCINES
FOR DENTAL HEALTH-CARE WORKERS
Although
HBV infection is uncommon among adults in the United
States (1%-2%), serologic surveys have indicated that
10%-30% of health-care or dental workers show evidence
of past or present HBV infection (6,32). The OSHA
bloodborne pathogens final rule requires that employers
make hepatitis B vaccinations available without cost to
their employees who may be exposed to blood or other
infectious materials (4). In addition, CDC recommends
that all workers, including DHCWs, who might be exposed
to blood or blood-contaminated substances in an
occupational setting be vaccinated for HBV (6-8). DHCWs
also are at risk for exposure to and possible
transmission of other vaccine-preventable diseases (33);
accordingly, vaccination against influenza, measles,
mumps, rubella, and tetanus may be appropriate for DHCWs.
PROTECTIVE
ATTIRE AND BARRIER TECHNIQUES
For
protection of personnel and patients in dental-care
settings, medical gloves (latex or vinyl) always must be
worn by DHCWs when there is potential for contacting
blood, blood-contaminated saliva, or mucous membranes
(1,2,4-6). Nonsterile gloves are appropriate for
examinations and other nonsurgical procedures (5);
sterile gloves should be used for surgical procedures.
Before treatment of each patient, DHCWs should wash
their hands and put on new gloves; after treatment of
each patient or before leaving the dental operatory,
DHCWs should remove and discard gloves, then wash their
hands. DHCWs always should wash their hands and reglove
between patients. Surgical or examination gloves should
not be washed before use; nor should they be washed,
disinfected, or sterilized for reuse. Washing of gloves
may cause "wicking" (penetration of liquids
through undetected holes in the gloves) and is not
recommended (5). Deterioration of gloves may be caused
by disinfecting agents, oils, certain oil-based lotions,
and heat treatments, such as autoclaving.
Chin-length
plastic face shields or surgical masks and protective
eyewear should be worn when splashing or spattering of
blood or other body fluids is likely, as is common in
dentistry (2,5,6,34,35). When a mask is used, it should
be changed between patients or during patient treatment
if it becomes wet or moist. Face shields or protective
eyewear should be washed with an appropriate cleaning
agent and, when visibly soiled, disinfected between
patients.
Protective
clothing such as reusable or disposable gowns,
laboratory coats, or uniforms should be worn when
clothing is likely to be soiled with blood or other body
fluids (2,5,6). Reusable protective clothing should be
washed, using a normal laundry cycle, according to the
instructions of detergent and machine manufacturers.
Protective clothing should be changed at least daily or
as soon as it becomes visibly soiled (9). Protective
garments and devices (including gloves, masks, and eye
and face protection) should be removed before personnel
exit areas of the dental office used for laboratory or
patient-care activities.
Impervious-backed
paper, aluminum foil, or plastic covers should be used
to protect items and surfaces (e.g., light handles or
x-ray unit heads) that may become contaminated by blood
or saliva during use and that are difficult or
impossible to clean and disinfect. Between patients, the
coverings should be removed (while DHCWs are gloved),
discarded, and replaced (after ungloving and washing of
hands) with clean material.
Appropriate
use of rubber dams, high-velocity air evacuation, and
proper patient positioning should minimize the formation
of droplets, spatter, and aerosols during patient
treatment. In addition, splash shields should be used in
the dental laboratory.
HANDWASHING
AND CARE OF HANDS
DHCWs
should wash their hands before and after treating each
patient (i.e., before glove placement and after glove
removal) and after barehanded touching of inanimate
objects likely to be contaminated by blood, saliva, or
respiratory secretions (2,5,6,9). Hands should be washed
after removal of gloves because gloves may become
perforated during use, and DHCWs' hands may become
contaminated through contact with patient material. Soap
and water will remove transient microorganisms acquired
directly or indirectly from patient contact (9);
therefore, for many routine dental procedures, such as
examinations and nonsurgical techniques, handwashing
with plain soap is adequate. For surgical procedures, an
antimicrobial surgical handscrub should be used (10).
When
gloves are torn, cut, or punctured, they should be
removed as soon as patient safety permits. DHCWs then
should wash their hands thoroughly and reglove to
complete the dental procedure. DHCWs who have exudative
lesions or weeping dermatitis, particularly on the
hands, should refrain from all direct patient care and
from handling dental patient-care equipment until the
condition resolves (12). Guidelines addressing
management of occupational exposures to blood and other
fluids to which universal precautions apply have been
published previously (6-8,36).
USE
AND CARE OF SHARP INSTRUMENTS AND NEEDLES
Sharp
items (e.g., needles, scalpel blades, wires)
contaminated with patient blood and saliva should be
considered as potentially infective and handled with
care to prevent injuries (2,5,6).
Used
needles should never be recapped or otherwise
manipulated utilizing both hands, or any other technique
that involves directing the point of a needle toward any
part of the body (2,5,6). Either a one-handed
"scoop" technique or a mechanical device
designed for holding the needle sheath should be
employed. Used disposable syringes and needles, scalpel
blades, and other sharp items should be placed in
appropriate puncture-resistant containers located as
close as is practical to the area in which the items
were used (2,5,6). Bending or breaking of needles before
disposal requires unnecessary manipulation and thus is
not recommended.
Before
attempting to remove needles from nondisposable
aspirating syringes, DHCWs should recap them to prevent
injuries. Either of the two acceptable techniques may be
used. For procedures involving multiple injections with
a single needle, the unsheathed needle should be placed
in a location where it will not become contaminated or
contribute to unintentional needlesticks between
injections. If the decision is made to recap a needle
between injections, a one-handed "scoop"
technique or a mechanical device designed to hold the
needle sheath is recommended.
STERILIZATION
OR DISINFECTION OF INSTRUMENTS Indications for
Sterilization or Disinfection of Dental Instruments
As
with other medical and surgical instruments, dental
instruments are classified into three categories --
critical, semicritical, or noncritical -- depending on
their risk of transmitting infection and the need to
sterilize them between uses (9,37-40). Each dental
practice should classify all instruments as follows:
Critical.
Surgical and other instruments used to penetrate soft
tissue or bone are classified as critical and should be
sterilized after each use. These devices include
forceps, scalpels, bone chisels, scalers, and burs.
Semicritical.
Instruments such as mirrors and amalgam condensers that
do not penetrate soft tissues or bone but contact oral
tissues are classified as semicritical. These devices
should be sterilized after each use. If, however,
sterilization is not feasible because the instrument
will be damaged by heat, the instrument should receive,
at a minimum, high-level disinfection.
Noncritical.
Instruments or medical devices such as external
components of x-ray heads that come into contact only
with intact skin are classified as noncritical. Because
these noncritical surfaces have a relatively low risk of
transmitting infection, they may be reprocessed between
patients with intermediate-level or low-level
disinfection (see Cleaning and Disinfection of Dental
Unit and Environmental Surfaces) or detergent and water
washing, depending on the nature of the surface and the
degree and nature of the contamination (9,38). Methods
of Sterilization or Disinfection of Dental Instruments
Before
sterilization or high-level disinfection, instruments
should be cleaned thoroughly to remove debris. Persons
involved in cleaning and reprocessing instruments should
wear heavy-duty (reusable utility) gloves to lessen the
risk of hand injuries. Placing instruments into a
container of water or disinfectant/detergent as soon as
possible after use will prevent drying of patient
material and make cleaning easier and more efficient.
Cleaning may be accomplished by thorough scrubbing with
soap and water or a detergent solution, or with a
mechanical device (e.g., an ultrasonic cleaner). The use
of covered ultrasonic cleaners, when possible, is
recommended to increase efficiency of cleaning and to
reduce handling of sharp instruments.
All
critical and semicritical dental instruments that are
heat stable should be sterilized routinely between uses
by steam under pressure (autoclaving), dry heat, or
chemical vapor, following the instructions of the
manufacturers of the instruments and the sterilizers.
Critical and semicritical instruments that will not be
used immediately should be packaged before
sterilization.
Proper
functioning of sterilization cycles should be verified
by the periodic use (at least weekly) of biologic
indicators (i.e., spore tests) (3,9). Heat-sensitive
chemical indicators (e.g., those that change color after
exposure to heat) alone do not ensure adequacy of a
sterilization cycle but may be used on the outside of
each pack to identify packs that have been processed
through the heating cycle. A simple and inexpensive
method to confirm heat penetration to all instruments
during each cycle is the use of a chemical indicator
inside and in the center of either a load of unwrapped
instruments or in each multiple instrument pack (41);
this procedure is recommended for use in all dental
practices. Instructions provided by the manufacturers of
medical/dental instruments and sterilization devices
should be followed closely.
In
all dental and other health-care settings, indications
for the use of liquid chemical germicides to sterilize
instruments (i.e., "cold sterilization") are
limited. For heat-sensitive instruments, this procedure
may require up to 10 hours of exposure to a liquid
chemical agent registered with the U.S. Environmental
Protection Agency (EPA) as a "sterilant/disinfectant."
This sterilization process should be followed by aseptic
rinsing with sterile water, drying, and, if the
instrument is not used immediately, placement in a
sterile container.
EPA-registered
"sterilant/disinfectant" chemicals are used to
attain high-level disinfection of heat-sensitive
semicritical medical and dental instruments. The product
manufacturers' directions regarding appropriate
concentration and exposure time should be followed
closely. The EPA classification of the liquid chemical
agent (i.e., "sterilant/disinfectant") will be
shown on the chemical label. Liquid chemical agents that
are less potent than the "sterilant/disinfectant"
category are not appropriate for reprocessing critical
or semicritical dental instruments.
CLEANING
AND DISINFECTION OF DENTAL UNIT AND ENVIRONMENTAL
SURFACES
After
treatment of each patient and at the completion of daily
work activities, countertops and dental unit surfaces
that may have become contaminated with patient material
should be cleaned with disposable toweling, using an
appropriate cleaning agent and water as necessary.
Surfaces then should be disinfected with a suitable
chemical germicide.
A
chemical germicide registered with the EPA as a
"hospital disinfectant" and labeled for "tuberculocidal"
(i.e., mycobactericidal) activity is recommended for
disinfecting surfaces that have been soiled with patient
material. These intermediate-level disinfectants include
phenolics, iodophors, and chlorine-containing compounds.
Because mycobacteria are among the most resistant groups
of microorganisms, germicides effective against
mycobacteria should be effective against many other
bacterial and viral pathogens (9,38-40,42). A fresh
solution of sodium hypochlorite (household bleach)
prepared daily is an inexpensive and effective
intermediate-level germicide. Concentrations ranging
from 500 to 800 ppm of chlorine (a 1:100 dilution of
bleach and tap water or 1/4 cup of bleach to 1 gallon of
water) are effective on environmental surfaces that have
been cleaned of visible contamination. Caution should be
exercised, since chlorine solutions are corrosive to
metals, especially aluminum.
Low-level
disinfectants -- EPA-registered "hospital
disinfectants" that are not labeled for "tuberculocidal"
activity (e.g., quaternary ammonium compounds) -- are
appropriate for general housekeeping purposes such as
cleaning floors, walls, and other housekeeping surfaces.
Intermediate- and low-level disinfectants are not
recommended for reprocessing critical or semicritical
dental instruments.
DISINFECTION
AND THE DENTAL LABORATORY
Laboratory
materials and other items that have been used in the
mouth (e.g., impressions, bite registrations, fixed and
removable prostheses, orthodontic appliances) should be
cleaned and disinfected before being manipulated in the
laboratory, whether an on-site or remote location (43).
These items also should be cleaned and disinfected after
being manipulated in the dental laboratory and before
placement in the patient's mouth (2). Because of the
increasing variety of dental materials used intraorally,
DHCWs are advised to consult with manufacturers
regarding the stability of specific materials relative
to disinfection procedures. A chemical germicide having
at least an intermediate level of activity (i.e., "tuberculocidal
hospital disinfectant") is appropriate for such
disinfection. Communication between dental office and
dental laboratory personnel regarding the handling and
decontamination of supplies and materials is important.
USE
AND CARE OF HANDPIECES, ANTIRETRACTION VALVES, AND OTHER
INTRAORAL DENTAL DEVICES ATTACHED TO AIR AND WATER LINES
OF DENTAL UNITS
Routine
between-patient use of a heating process capable of
sterilization (i.e., steam under pressure {autoclaving},
dry heat, or heat/chemical vapor) is recommended for all
high-speed dental handpieces, low-speed handpiece
components used intraorally, and reusable prophylaxis
angles. Manufacturers' instructions for cleaning,
lubrication, and sterilization procedures should be
followed closely to ensure both the effectiveness of the
sterilization process and the longevity of these
instruments. According to manufacturers, virtually all
high-speed and low-speed handpieces in production today
are heat tolerant, and most heat-sensitive models
manufactured earlier can be retrofitted with heat-stable
components.
Internal
surfaces of high-speed handpieces, low-speed handpiece
components, and prophylaxis angles may become
contaminated with patient material during use. This
retained patient material then may be expelled
intraorally during subsequent uses (44-46). Restricted
physical access -- particularly to internal surfaces of
these instruments -- limits cleaning and disinfection or
sterilization with liquid chemical germicides. Surface
disinfection by wiping or soaking in liquid chemical
germicides is not an acceptable method for reprocessing
high-speed handpieces, low-speed handpiece components
used intraorally, or reusable prophylaxis angles.
Because
retraction valves in dental unit water lines may cause
aspiration of patient material back into the handpiece
and water lines, antiretraction valves (one-way flow
check valves) should be installed to prevent fluid
aspiration and to reduce the risk of transfer of
potentially infective material (47). Routine maintenance
of antiretraction valves is necessary to ensure
effectiveness; the dental unit manufacturer should be
consulted to establish an appropriate maintenance
routine.
High-speed
handpieces should be run to discharge water and air for
a minimum of 20-30 seconds after use on each patient.
This procedure is intended to aid in physically flushing
out patient material that may have entered the turbine
and air or water lines (46). Use of an enclosed
container or high-velocity evacuation should be
considered to minimize the spread of spray, spatter, and
aerosols generated during discharge procedures.
Additionally, there is evidence that overnight or
weekend microbial accumulation in water lines can be
reduced substantially by removing the handpiece and
allowing water lines to run and to discharge water for
several minutes at the beginning of each clinic day
(48). Sterile saline or sterile water should be used as
a coolant/irrigator when surgical procedures involving
the cutting of bone are performed.
Other
reusable intraoral instruments attached to, but
removable from, the dental unit air or water lines --
such as ultrasonic scaler tips and component parts and
air/water syringe tips -- should be cleaned and
sterilized after treatment of each patient in the same
manner as handpieces, which was described previously.
Manufacturers' directions for reprocessing should be
followed to ensure effectiveness of the process as well
as longevity of the instruments.
Some
dental instruments have components that are heat
sensitive or are permanently attached to dental unit
water lines. Some items may not enter the patient's oral
cavity, but are likely to become contaminated with oral
fluids during treatment procedures, including, for
example, handles or dental unit attachments of saliva
ejectors, high-speed air evacuators, and air/water
syringes. These components should be covered with
impervious barriers that are changed after each use or,
if the surface permits, carefully cleaned and then
treated with a chemical germicide having at least an
intermediate level of activity. As with high-speed
dental handpieces, water lines to all instruments should
be flushed thoroughly after the treatment of each
patient; flushing at the beginning of each clinic day
also is recommended.
SINGLE-USE
DISPOSABLE INSTRUMENTS
Single-use
disposable instruments (e.g., prophylaxis angles;
prophylaxis cups and brushes; tips for high-speed air
evacuators, saliva ejectors, and air/water syringes)
should be used for one patient only and discarded
appropriately. These items are neither designed nor
intended to be cleaned, disinfected, or sterilized for
reuse.
HANDLING
OF BIOPSY SPECIMENS
In
general, each biopsy specimen should be put in a sturdy
container with a secure lid to prevent leaking during
transport. Care should be taken when collecting
specimens to avoid contamination of the outside of the
container. If the outside of the container is visibly
contaminated, it should be cleaned and disinfected or
placed in an impervious bag (49).
USE
OF EXTRACTED TEETH IN DENTAL EDUCATIONAL SETTINGS
Extracted
teeth used for the education of DHCWs should be
considered infective and classified as clinical
specimens because they contain blood. All persons who
collect, transport, or manipulate extracted teeth should
handle them with the same precautions as a specimen for
biopsy (2). Universal precautions should be adhered to
whenever extracted teeth are handled; because
preclinical educational exercises simulate clinical
experiences, students enrolled in dental educational
programs should adhere to universal precautions in both
preclinical and clinical settings. In addition, all
persons who handle extracted teeth in dental educational
settings should receive hepatitis B vaccine (6-8).
Before
extracted teeth are manipulated in dental educational
exercises, the teeth first should be cleaned of adherent
patient material by scrubbing with detergent and water
or by using an ultrasonic cleaner. Teeth should then be
stored, immersed in a fresh solution of sodium
hypochlorite (household bleach diluted 1:10 with tap
water) or any liquid chemical germicide suitable for
clinical specimen fixation (50).
Persons
handling extracted teeth should wear gloves. Gloves
should be disposed of properly and hands washed after
completion of work activities. Additional personal
protective equipment (e.g., face shield or surgical mask
and protective eyewear) should be worn if mucous
membrane contact with debris or spatter is anticipated
when the specimen is handled, cleaned, or manipulated.
Work surfaces and equipment should be cleaned and
decontaminated with an appropriate liquid chemical
germicide after completion of work activities
(37,38,40,51).
The
handling of extracted teeth used in dental educational
settings differs from giving patients their own
extracted teeth. Several states allow patients to keep
such teeth, because these teeth are not considered to be
regulated (pathologic) waste (52) or because the removed
body part (tooth) becomes the property of the patient
and does not enter the waste system (53).
DISPOSAL
OF WASTE MATERIALS
Blood,
suctioned fluids, or other liquid waste may be poured
carefully into a drain connected to a sanitary sewer
system. Disposable needles, scalpels, or other sharp
items should be placed intact into puncture-resistant
containers before disposal. Solid waste contaminated
with blood or other body fluids should be placed in
sealed, sturdy impervious bags to prevent leakage of the
contained items. All contained solid waste should then
be disposed of according to requirements established by
local, state, or federal environmental regulatory
agencies and published recommendations (9,49).
IMPLEMENTATION
OF RECOMMENDED INFECTION-CONTROL PRACTICES FOR DENTISTRY
Emphasis
should be placed on consistent adherence to recommended
infection-control strategies, including the use of
protective barriers and appropriate methods of
sterilizing or disinfecting instruments and
environmental surfaces. Each dental facility should
develop a written protocol for instrument reprocessing,
operatory cleanup, and management of injuries (3).
Training of all DHCWs in proper infection-control
practices should begin in professional and vocational
schools and be updated with continuing education.
ADDITIONAL
NEEDS IN DENTISTRY
Additional
information is needed for accurate assessment of factors
that may increase the risk for transmission of
bloodborne pathogens and other infectious agents in a
dental setting. Studies should address the nature,
frequency, and circumstances of occupational exposures.
Such information may lead to the development and
evaluation of improved designs for dental instruments,
equipment, and personal protective devices. In addition,
more efficient reprocessing techniques should be
considered in the design of future dental instruments
and equipment. Efforts to protect both patients and
DHCWs should include improved surveillance, risk
assessment, evaluation of measures to prevent exposure,
and studies of postexposure prophylaxis. Such efforts
may lead to development of safer and more effective
medical devices, work practices, and personal protective
equipment that are acceptable to DHCWs, are practical
and economical, and do not adversely affect patient care
(54,55 ).
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SUGGESTED
CITATION: Centers for Disease Control and Prevention.
Recommended infection-control practices for dentistry,
1993. MWMR 1993;42(No. RR-8):{inclusive page numbers}.
Use
of trade names is for identification only and does not
imply endorsement by the Public Health Service or the
U.S. Department of Health and Human Services.
CIO
Responsible for this publication: National Center for
Prevention Services,
Division
of Oral Health
Kate Foster Health
Correspondent
Tuesday, 24th July 2001
The Scotsman
Being a dentist
myself, I am very well aware of the spread of bloodborne
pathogens in dentistry. Since dentistry was
'deregulated' in the late '70s and taken over by managed
care companies - dentists have l | 
