INTRODUCTION WHY DO WE NEED TO KNOW ABOUT INFECTION CONTROL ? THE GOAL OF INFECTION CONTROL IS TO ELIMINATE OR REDUCE THE NUMBER OF MICROBES SHARED BETWEEN PEOPLE. IMPLEMENTING SAFE AND REALISTIC INFECTION CONTROL PROCEDURES REQUIRES THE FULL COMPLIANCE OF THE WHOLE DENTAL TEAM.
Infection control in dentistry ¤ Training regarding infection control ¤ Surgery design ¤ Choice of equipment ¤ Decontamination of instruments and equipment ¤ Single use (disposable) items ¤ Surface cleaning and disinfection ¤ Decontamination of instruments and equipment prior to service or repair ¤ Decontamination of impression materials and prosthetic and orthodontic appliances ¤ Disposal of clinical waste ¤ Blood spillages ¤ Biopsy specimens sent through the post
¤ Immunization ¤ Hand protection by gloves ¤ Eye protection and face masks ¤ Surgery clothing ¤ Aerosol and saliva/blood splatter ¤ preventing Inoculation injuries PERSONAL PROTECTION ¤ Preventing Transmission of Blood Borne Pathogens ¤ Hepatitis B Virus ¤ Hepatitis D Virus ¤ Hepatitis C Virus ¤ Human Immunodeficiency Virus ¤PRE Exposure Prevention Methods ¤ Postexposure Management and Prophylaxis Blood borne Pathogens
Concept of Infection The number of organisms required to cause an infection is termed as “The infective dose”.
General Principles Universal precautions – use of mouth mask, head cap, protective eye were gloves are recommended. Hand washing and care of hands Sir William Osler once remarked that Soap and water and common sense are the best disinfectants. Use of commonly available antiseptic hand wash like chlorhexidine is generally enough.
Ventilation – The recommended fresh air supply rate of ventilation systems should not fall below 5-8 liters per second per occupant.
Recycling air conditioning systems are not recommended.
The floor covering should be impervious and non slippery.
Carpet must be avoided.
ENVIRONMENT OF DENTAL OFFICE
High speed hand piece is capable of creating air borne contaminants from bacterial residents from saliva. Aerosols Particle size range from 50 um to approximately 5 um. That can remain suspended in the air and breathed for hrs. Cross infections. Patients infected usually are not aware of the source of their infection and some time they even don’t know that he is infected. AIR BORNE CONTAMINATION
Immunization - Hepatitis B infection Anti – HBs levels must be measured 2-4 months after complete immunization course. HBS level > 100 M/U/ml will provided adequate protection. Single booster dose 5 years after completion of primary course is recommended for all health care workers. PERSONAL RISK
Infections diseases of concern in dentistry. Bacteria Viruses N.Gonorrhoeae Hepatitis B,C,D T. Pallidum H.I.V. M. Tuberculosis Cytomegalo virus Strep. Pyogenes Measles Mumps Rubella Herpes
Sterilization – Sterilization is the destruction or complete removal of all forms of micro organisms. Disinfection – Disinfection is the destruction of many microorganisms but not usually the bacterial spores. METHODS OF INFECTION CONTROL
Choice of equipments depends upon the requirement of the practitioners. Water supplies The ADA council on scientific affairs recommends to improve the design of dental equipment of that water delivered to patients during non surgical dental procedures it should contains no more than 200 colony forming units / ml (cfu/ml) of bacteria at any point of time in the unfiltered output of dental unit. CHOICE OF EQUIPMENTS
Bio-films of vegatitive form of bacterias spores and the organic matter formed on the surface of the instrument have to be washed with the suitable disinfectant before proceeding with the sterilization process. PRE-STERILIZATION CLEANING
Physical agents Heat – Moist, Dry Ionizing radiations X-rays, beta rays gamma rays Ultraviolet rays Filtration Chemical agents Agents acting on cell membrane Surface acting agents, Phenols, Organic solvents Agents that denature proteins Acids and alkalies Agents acting on functional group of proteins Heavy metals Oxidizing agents, Dyes, Alkylating agents. STERILIZATION
Steam Pressure Sterilization (Autoclaving) Long cycle of 15 min – 121 degree Celsius and 15 lbs pressure. Short cycle of 7 min – 134 degree Celsius and 30 lbs pressure. Advantage of autoclaves - Most rapid and effective methods for sterilization of commonly used dental equipments. Disadvantages of Autoclaves – Can cause rusting of carbon steel instruments. Dental burs can be autoclaved after dipping it into 2 % sodium nitrite sol. AUTOCLAVE
Dry Heat Sterilization – Hot air oven Dry heat at 160 degree Celsius is commonly used for this purpose. Microbial inactivation by dry heat is primarily an oxidation process. Employed for sterilization of glassware, glass syringes, oily injection as well as metal instruments. Chemiclaving – Using ethylene oxide gas 131 degree celsius 20 pounds pressure is use for this purpose. Heat sensitive plastic instrument are sterilized by this method.
Not effective against RNA viruses like HIV and bacterial spores.
Not commonly employed in dental practice.
Glass bead sterilizer – used for sterilization of endodontic files.
NEW METHODS OF STERILIZATION
Hand piece – Should be well disinfected before sterilization Hot oil sterilization can be used for this. Autoclaving is commonly carried out. Sterilization of impression (Vinyl Polysiloxane)or Rubber Based Impression. – done by dipping them in 2 % gluteraldehyde solution for minimum of 2 hours. These should be wrapped in sterile bag. TYPES OF INSTRUMENTS AND STERILIZATION METHODS.
Classification and management Category Waste Type Treatment and Disposal Method Category 1 Human Wastes (Tissues, organs, body parts Incineration / deep burial Category 2 Animal Waste Incineration / deep burial Category 3 Microbiology & Biotechnology waste Autoclave/microwave/ incineration Category 4 Sharps Disinfection (chemical treatment)+autoclaving/ microwaving . Category 5 Discarded Medicines and Cytotoxic Drugs Incineration/ destruction and drugs disposal in secured landfills
Category Waste Type Treatment and Disposal Method Category 6 Contaminated solid waste Incineration/autoclaving / microwaving Category 7 Solid waste (disposable items other than sharps) Disinfection by chemical treatment+ microwaving/autoclaving Category 8 Liquid waste (generated from laboratory washing, cleaning, housekeeping and disinfecting activity) Disinfection by chemical treatment+ and discharge into the drains Category 9 Incineration ash Disposal in municipal landfill Category10 Chemical Wastes Chemical Treatment + and discharge in to drain for liquids and secured landfill for solids
Management Color coding Type of container Waste category treatment option YELLOW PLASTIC BAG Cat 1,2,3,6 Incineration / deep burial RED Disinfected container / plastic bag Cat 3,6,7 Autoclave/microwave /chemical treatment Blue/white translucent Plastic bag/ Puncture proof Cat 4,7 Autoclave/microwave /chemical treatment / destruction shredding BLACK Plastic bag Cat 5,9,10 Disposal in secure landfill
1. FIRST AID o Contaminated Wound - Encourage bleeding from the skin wound and wash the injured area with copious soapy water, disinfectant, scrub solution or water. o Contaminated Intact Skin - Wash the area with soap and water. o Contaminated Eyes - Gently rinse the eyes while open with Saline or water. o Contaminated Mouth - Spit out any fluid - rinse the mouth with water and spit out again. 2. REPORT ACCIDENT PROTOCOL TO BE FOLLOWED AFTER A NEEDLESTICK INJURY OR BLOOD/BODY FLUID EXPOSURE.
If the patient is known to be HIV positive then the exposed Health Care Worker should be given counseling and offered Post exposure prophylaxis (PEP). HIV post exposure chemoprophylaxis for health workers.
Basic (28 days) – Zidovudine + Lamivudine
Expanded (28 days) – As above + Indinavir or nelfinavir or neviriapine
General Practitoner need to know where they can access the PEP drugs as they should be given within 72 hours following exposure.