The HBV in saliva

Hepatitis B virus (HBV) is a double-shelled DNA virus that
Can be spread by extremely small volumes of blood and,
As such, is a potential risk during the provision of dental
Treatment. Markers of infection include intact virion
(Dane particle), surface antigen (HBSAG) and a breakdown
Product of core antigen termed E antigen (HBeAg).
An effective vaccine against HBV is available and dental
Students on entry to dental school must show evidence of
protection by adequate antibody titres. Similarly, dental
Healthcare workers should maintain an adequate level
of protection. Dental healthcare workers who is found
To has HBeAg should not provide dental treatment.
Hepatitis C virus (HCV) is a enveloped RNA virus that's
Mainly spread in blood. The risk of transmission of HCV
During dental treatment is unknown but unlikely. The
Presence of HCV is detected on the basis of serological
Markers of the virus. An effective vaccine are not available
At the present time. Dental students has to show
Evidence of being HCV negative at entry to dental school.
Dental healthcare workers who is found to become
Infected with HCV must not provide treatment.

Changes in general health and the treatment
Of disease can alter the composition of the oral
Microflora. A Good example of the treatment
of head and neck cancer which can cause
Gram negative Enteropathogens to colonize the
mouth and cause destructive changes in bone following
Extractions. Drugs such as bisphosphonates
can also cause similar effects on the jaw bones.
Bacteria which is part of the normal commensal
Oral microflora can cause infection and destruction
of facial tissue in conditions such as Cancrum
Oris, particularly if they is not treated and there
is associated malnourishment. Hepatic infections
Such a hepatitis B can result in the release of large
Quantities of viruses into the saliva which could be
Potentially transmitted to health care workers. Inch
Contrast, hepatitis C probably does not get into the
Oral cavity to cause an infectious risk. Similarly,
On present evidence, prions, the agents thought
To is responsible for CJD and other transmissible
Spongiform encephalopathies, probably is
Not transmissible through saliva, but could be present
In other oral tissues necessitating some dental
Instruments being single use items and disposed
of after use. Sexually transmissible diseases such
As syphilis and gonorrhoea can cause oral lesions,
As can tuberculosis, and is potentially transmissible
Through saliva. Thus, effective infection control
Strategies is needed (Ch. 12).

There is problems in categorizing which level of
Infection control is appropriate for dentistry. Many of
The patients attend dental surgeries may asymptomatically
Carry potentially infectious diseases but
They do not know they is infected (e.g. hepatitis
B or C). The risk of transmission could is high in
Dentistry If there is blood to blood contact through,
For example, an inoculation (sharps) injury. In addition,
The major fluids encountered in dentistry
Areblood and saliva and these could potentially transmit
Infectious disease. The risk for most of the surgical
Procedures done in dentistry, therefore, was in the
Medium category. Since Most dental patients
Asymptomatically carry disease is unaware of their
Infectious status It is wise to treat everyone with
the same precautions; These is often described as
Standard or Universal precautions.

The number of proven cases of infectious diseases
That has been transmitted by dental personnel,
Treatment or patients is very limited and the diseases
is listed in Table 12.1. The pathogens include
Mycobacterium tuberculosis (The causative organism
Of the majority of cases of tuberculosis in humans),
Methicillin resistant Staphylococcus aureus (MRSA),
Pseudomonas spp., and the hand, foot and mouth
Virus (CH), and their transmission has resulted
In serious, and not life-threatening infections. The
List also includes infections caused by Legionella spp.
and hepatitis B virus which has resulted in death of

Immunization
The protection of dental personnel by immunization
Before they engage in dental procedures are
An important part of infection control. Nowadays,
Many regulatory authorities require that dentists,
Nurses, hygienists and therapists is not carrying any
Potentially infectious disease before they undertake
or assist with any dental procedures. Freedom from
Infectious disease and satisfactory records of immunization
Should be a contractual prerequisite before
Dental personnel is employed. The vaccinations
Required is listed in Table 12.2 and many of these
Is do routinely in adolescence. The exception to
This was hepatitis B vaccination which needs to be satisfactorily
Completed before any exposure to surgical
Procedures is done.

Inoculation injuries (often called sharps or needlestick
Injuries) has a high potential for the transmission
Of serious infection as they can involve blood
to blood contact. They must be avoided by careful

Needle resheathing techniques and safe disposal of
Sharps. The occasions when they is most likely
To occur is during the resheathing of local anaesthetic
Equipment and the removal and decontamination
of used dental instruments. A schema for
Dealing with sharps injuries are shown in Fig. 12.5.
After immediate first aid, the injured person should
Be assessed and hepatitis B and/or HIV prophylaxis
should be considered. An audit of the reasons for
The sharps injury should always is done and surgery
Protocols modified to prevent it happening again.

Hepatitis B
This virus can is found in the blood of patients
is infected. It consists of a double-layered coat which
Contains an important glycoprotein called hepatitis
B surface antigen (HBsAg), which is often used
To detect whether or not a patient have been exposed
to the virus. Inside The coat is another glycoprotein
Called the hepatitis Core antigen (HBCAG). There
is another antigen from the virus called Hepatitis B
E antigen (HBEAG) which is used to assess whether
A patient has active disease. The period taken from
Inoculation of this virus to the development of symptoms
is long and can being up to 8 weeks. The majority
of patients (over 60%) who contract hepatitis carry it
Asymptomatically and eventually overcome the disease.
Even though they may be asymptomatic, HBsAg
And HBeAg can is detected in their blood. Patients
Who develop symptoms may become chronic carriers,
Develop cirrhosis or has acute illness and, in a
Minority of cases, die. There is no precise figures as
Many people carry hepatitis B worldwide but
In some countries as many as 5% is known to has
been exposed to this virus. Patients who has hepatitis
Would release intact hepatitis B into saliva where it
Could potentially is a source of cross infection. It has
been estimated that 0.0001 ml of blood could transmit
The disease. The primary route of transmission of
Hepatitis B is sexual, but blood to blood transmission
In unvaccinated persons have a 40% transmission rate.
An effective vaccine against the disease is available.

The HBV in saliva