Dental Assisting DNT 354 (Sterilization) By Dr. Kifaya Ifthikar

Contents Sterilization Importance of sterilization 3) Success of sterilization 4)Methods of Sterilization

Sterilization It’s a process effectively kill or eliminates all forms of living micro organisms including spores. By physical & Chemical methods Importance of sterilizations >Most important method of infection control in the dental office >Effective microbial kill with minimal instrument damage >Best method for Dental instrument sterilization

Success of sterilization >Properly clean the dental instrument before sterilization. Devide the patient care devices according to the risk of infection >Do not overload the sterilizer punch can occur in the rapped packs >Do not remove the instruments prior to completion of the cycle >Proper storage of the instruments in a closed dry cabinet

>Regularly clean & maintain the sterilizer >Monitoring the sterilization >Indicators can be used to monitor >External indicators printed on the packing materials 4) Method of Sterilization 1)Physical Methods a)Dry Heat Widely used method& non corrosive Reliable method Can only apply for thermoplastic materials Dry Heat (1600-1800 c) One hour exposure time& good penetrability Much lower time exposure required to kill the microbes Hot air oven( iol,fats,metal surgical instruments)

b) Incineration ; Excellent method of destroying materials b) Incineration ; Excellent method of destroying materials. Materials are reduced to ashes by burning >Contaminated clothes >Pathological materials >Beddings c) Filtration >Does not destroy the microorganism only remove them. >Sterilize sera ,sugars & Antibiotic solution >Sieving >Purification of water

> b)Moist Heat >Act as Steam under pressure(1210-1340for 15-20 mints) >Kill microorganisms by coagulating proteins. >Ability to processes a wide range of materials >Rapid & effective >Most economical method of Sterilization. Autoclave

2)Methods of Radiation; Used on material that cannot be Sterilized by heat or chemicals a)Non Ionizing >Ultra violet rays & Infra red rays Poor energy , less penetration & hazardous >Surface Sterilization for aseptic work area. Sterilization of pre packed items b)Ionizing >X- rays >Gamma Rays >Very effective method due to high penetrating power Commercial use, for sterilization of disposable items Antibiotics & Hormones Articles should be in dry states >Very expensive

Chemical methods;1 >Wide spectrum of activity >Speed action >High penetrating power >Not corrode the metal >Not cause local irritation >Cheap & safety >Mode of Action: Disruption of cell membrane. >Protein coagulation a)Alcohol -Ethanol/ Isopropyl alcohol -Frequently used -No action on spores -Disinfection of clinical thermometers b)Formaldehydes :Bactericidal &Sporicidal -Lethal effect on viruses -Preserve anatomical specimens .

c) Gulutaraldehyde :Effect against Tubercle bacilli , Fungi & viruses >Sterilization of endoscopes & surgical instruments d)Phenol >Powerful microbial substance >Toxic & corrosive >Disinfect surgical instruments ,contaminated materials and floor Gases Ethylene Oxide >Highly penetrating gas oxide >Effective against all types of viruses & spores . > Sterilization of lung machines , respirator, artificial heart valves Operation theater, Glasses