Infection Control In Dentistry Question And Answers

Infection Control In Dentistry

Question 1. What are the universal precautions and what is the importance of personal protection and immunization?
Answer. Universal precautions refers to the act of avoiding contact with patient’s body fluids by the means of wearing nonporous articles such as medical gloves, goggles, and face shields. Medical instruments especially scalpels and hypodermic needles should be handled carefully and disposed of properly in a sharp container.

Pathogens fall into two broad categories 1. blood borne (carried in the body fluids) and 2. air borne. Standard universal precautions cover both types.

Universal precautions should be practiced in any environment where workers are exposed to body fluids such as:

• Blood
• Semen
• Vaginal secretions
• Synovial fluid
• Amniotic fluid
• Cerebrospinal fluid
• Pleural fluid
• Peritoneal fluid
• Pericardial fluid.

Read And Learn More: Public Health Dentistry Question And Answers

These are the procedures to be followed by all staff who are caring for a patient believed to be harboring a highly contagious dangerous pathogen such as acquired immunodeficiency syndrome (AIDS) that is transmitted in blood, blood products and other body fluids.

Following are the universal precautions:

• Care in handling sharp objects like needles, blades.
• All cuts and abrasions in an HIV patient should be covered with a waterproof dressing.
• Minimal parenteral injections.
• Equipment and areas which are contaminated with secretions should be wiped with sodium hypochlorite solution or 2% glutaraldehyde.
• Contaminated gloves, cottons should be incinerated.
• Equipment should be disinfected with glutaraldehyde.
• Disposable equipment (drapes,scalpels,etc.) should be used whenever possible.
• Walls and floor should be cleaned properly with soap water.
• Separate operation theater and staff to do surgeries to HIV patients is justifiable.
• Avoid shaving whenever possible before surgery in HIV patients.
• All people inside the theater should wear disposable gowns, plastic aprons, goggles, overshoes and gloves.
• Surgeons, assistants and scrub nurse should wear in addition double gloves.
• Suction bottle should be half–filled with freshly prepared glutaraldehyde solution.
• Soiled body fluids should be diluted with glutaraldehyde.
• Accidental puncture area in surgeon or scrub nurse should immediately washed with soap and water thoroughly.
• Theater should be fumigated after surgery to HIV patient.

Importance of Immunization

Vaccines and toxoids may also contain adjuvants, substances that enhance the immune response as well as preservatives. Some vaccines (particularly live, attenuated vaccines) provide long-term, even lifelong protection following administration of only a single dose. The vaccines are truly cost saving although modern vaccines are safe and effective.

Immunization provides protection both to the individuals immunized and to the community because immunized individuals do not transmit disease. This “herd immunity” has led to the disappearance of disease in defined geographic areas, even though not everyone has received vaccine. Although this will mean that there is a greater opportunity for the prevention of disease and death.

Immunizations have been among the most successful public health interventions to date. Through appropriate use of vaccines, smallpox has been eradicated from the earth, poliomyelitis is on the verge of eradication, and there have been dramatic reductions in morbidity and mortality due to with many other diseases. Recent scientific advances give promise that even more diseases can be brought under effective control. A remaining challenge is to ensure that all people of the world benefit from immunizations.

Question 2. Write a short note on infection control in dental clinic.
Answer. Infection: The entry or multiplication of an infection agent in the body of man or animal.

Spread of Infection

The mode of transmission of infection may be classified as:

Direct Transmission

• Direct contact: From skin to skin, mucosa to mucosa or mucosa to skin of the same or another person.
• Droplet infection: Direct projection of a spray of droplets of saliva and nasopharyngeal secretion during coughing, sneezing or speaking and spitting.
• Contact with soil.
• Inoculation into skin or mucosa: The microorganism or disease agents may be inoculated directly into the skin or mucosa.
• Transplacental.

Indirect Transmission

Variety of mechanism including the transition flies, fingers, fomites, food and fluids.

• Vehicle borne: Transmission of infectious agents through the water, food, ice, blood, serum, plasma or other biological products such as tissue and organs.
• Vector-borne: Vector is defined as an arthropod or any living carrier, e.g. snail.
  • Transmission by a vector may be mechanical or biological.
• Air borne
  • Droplet nuclei: Droplet nuclei are a type of particles implication in the spread of airborne infection.
  • Dust: Some large droplets which are expelled during talking, coughing or sneezing become part of the dust.
    • Dust particles may also be blown from the soil by wind.
• Fomites borne: Fomites are inanimate articles or substances other than water and food contaminated by infections discharges.
• Uncleaned hand and fingers: Hands are the most common medium by which pathogenic agents are transferred to food from skin, nose, bowel, etc.

Prevention of Infection in Dental Clinic

• The dental environment is associated with a significant risk of exposure to various microorganisms.
• Dental patients and dental health care workers (DHCWs) may be exposed to a variety of microorganisms via blood or oral respiratory secretions.
• Infection control in dental clinic is essential to protectthemselves and their patients.
• Vaccine for dental health care workers
  • Hepatitis B vaccination to the employers who may be exposed to blood or other infectious materials.
• Protective attire and barrier techniques
  • For protection of personnel and patient in dental care setting, medical gloves always must be worn by DHCWs.
  • Non-sterile gloves are appropriate for examination and other nonsurgical procedures and sterile gloves should be used for surgical procedures.
  • Chin length plastic face shields or surgical marks and protective eyewear should be worn.
  • Protective clothing such as reusable or disposable gowns, laboratory coats or uniforms.
  • Impervious-backed paper, aluminum foil or elastic covers should be used to protect surfaces.
  • Appropriate use of rubber dams, high-velocity air evacuation and proper patient positioning should minimize the formation of droplets, spatter and aerosol during treatment.
• Handwash and care of hands
  • DHCWs should wash their hands before and after treatment of each patient to be contaminated by blood, saliva or respiratory secretion.
• Use and care of sharp instruments
  • Handle with care to prevent injuries with infected sharp instruments (needle, scalpel, blade, wires).
• Sterilization or Disinfection of instruments
  • The three most commonly used methods of sterilization in dentistry are:
    • The steam autoclave
    • The unsaturated chemical vapor sterilizer (Chemical)
    • Dry heat ovens.

Other Methods

• Exposure to ethylene oxide gas
• Boiling water
• Ionizing radiation
• Autoclave (steam under pressure)
• All living organisms are rapidly destroyed at 121°C temperature at 15 lbs pressure for 15 minutes
• Unsaturated chemical vapor sterilizer
• This sterilizer uses a special chemical solution containing formaldehyde and alcohol.
• Dry heat sterilizer (Hot air oven)
  • This uses hot air to kill microorganism and do not cause corrosion.
  • Air temperature of about 320° F for 60-120 minutes.

Question 3. How will you control infection in hospital? Describe suitable method of disposal of hospital waste.
Answer.

Disposal of Hospital Waste

• Hospital waste is defined as all the waste generated by healthcare establishments, research facilities and laboratories.
• Waste produced in the course of healthcare activities carries a higher potential for infection and injury than any other type of waste.

Procedure of Disposal of Hospital Waste

Procedure involves handling, storage and transportation:

• Color-coded plastic bags or container should be used for identification of waste.
• Sharps should be collected in container and the container should be puncture proof, rigid, impermeable, tamperproof and with covers.
• Bags and containers for infectious waste should be marked.
• Highly infectious waste should be preferably be packed into red bags and sterilized immediately by the autoclaving.
• Bags should be tightly closed or sealed.
• Waste should be stored in a separated area.
• Waste should be transported by means of wheeled trolleys, containers or carts that are not used for any other purposes.

Treatment and Disposal Technique for Waste

• Incineration
• Chemical disinfection
• Wet thermal treatment
• Microwave irradiation
• Encapsulation
• Safety burying
• Inertization.

Incineration

• Incineration is a high temperature dry oxidation process that reduces organic and combustible waste to inorganic and result in a very significant reduction of waste volume and weight.
• This process is usually used to treat wastes that cannot be recycled or reused.
• The incineration consists of:
  • A furnace or combustion chamber maintained at over 120°.
  • A platform for tipping the refuse.
  • Stokers for ranking the refuse forward.
  • Baffle plate to drive out all fumes.

Types

• Double chamber pyrolytic incineration
• Single chamber furnace with static grate
• Rotatory kilns.

Disposal of hospital waste Disadvantages

• Expensive
• Moisture presence during rainy season affect burning of refuse.

Chemical Disinfection

• In this method, chemicals are added to waste to kill or inactivate the pathogens.
• This method is most suitable for treating the liquid waste such as blood, urine, stool or hospital sewage.
• Types of chemical disinfectants: Formaldehyde, ethylene oxide, glutaraldehyde, sodium hypochlorite, chlorine dioxide.

Wet Thermal Treatment

Wet thermal treatment or steam disinfection is based on the exposure of shredded infectious waste to high temperature, high pressure steam. It inactivates most types of microorganisms.

Microwave Irradiation

• Most microorganisms are destroyed by the action of microwaves.
• The water contained within the wastes is rapidly heated by microwave and infection components are destroyed by heat conduction.

Encapsulation

• Encapsulation process involves filling containers which are made of high density polyethylene or metal drums with waste.
• These containers are then filled up with a medium of immobilizing material such as plastic foam, cement mortar or clay.
• As soon as the medium is dried, the containers get sealed and disposed off in landfill sites.
• It is simple, low cost and safe method.

Safe Burying

Safe burial of waste is used when it is the only viable option available especially in the establishments which use minimal program for health care waste management. Following are the rules which have to be followed:

• Disposal site access should be restricted to authorizedpersonnel only.
• The burial site should be lined with clay.
• Only hazardous healthcare waste is buried for conserving the space.
• Large quantities of chemical waste should not be buried at one time for avoiding the environmental pollution.
• Burial site should be covered with a layer of earth to prevent health hazards.

Inertization

• The process involves mixing waste with cement and other substances before disposal. This is done in the order to minimize the risk of toxic substances which are present in the waste migrating into surface water or ground water.
• Suitable for pharmaceuticals and for incineration ashes with a high metal content.
• Inexpensive method of waste disposal but is not applicable to infectious waste.