13. Definition of sterilization, sterilization methods in dentistry Flashcards
- Definition of sterilization
Completing destruction of all forms of microorganisms, including bacterial spreads
- What are the types of instruments sterilized?
All instruments contaminated with oral or body fluids are sterilized
- the phases of sterilization
a/ What are the phases of sterilization?
1/ Pre-sterilization cleaning
2/ Sterilization (methods of sterilization)
3/ Aseptic storage
- the phases of sterilization
b/ What should we do during Pre-sterilization cleaning?
- Collecting instruments
- Disinfection
- Cleaning before sterilization
- Revision
- Packing
- the phases of sterilization
c/ What are the 2 methods of cleaning before sterilization?
◦Method 1: Manual
‣ Using heavy-duty gloves (personal protection)
‣ Wearing mask, eyewear and gown
◦Method 2: Using ultrasonic detergent
‣ cavitation: a process having oscillating bubbles
=> These bubbles acting on debris to remove them
‣ Using detergent solution (not disinfectant)
- the phases of sterilization
d/ How do we pack instruments in pre-sterilization?
◦ Instruments must be dry before packaging
◦ Combination paper/plastic pouches
◦ Allow penetration of heat, steam
- the phases of sterilization
e/ Characteristics of aseptic storage?
- dry, closed storage
- Single, hermetic nylon holder
- same holder for sterilization and storage
- sterile storage is assured by intact holder
- Sterile holders can be opened directly before use
- it is strictly forbidden to store packages without signs on it
- Methods of sterilization
a/ Classification of sterilization methods
- Methods of sterilization
a/ What are the 2 types of sterilization methods?
Physical and chemical
- Methods of sterilization
a/ What are the 2 types of physical sterilization methods?
- Heat
- Radiation
- Methods of sterilization
b/ What are the 4 types of heat sterilization methods?
- Burning
- Dry heat
- Steam
- Cold
- Methods of sterilization
c/ Characteristics of dry heat sterilization methods?
◦ Dry heat
‣ High temperature for extended periods to achieve sterilization of instruments (circulating hot air)
‣ Advantage: do not dull instruments edge or corrode
‣ Disadvantage
* Less reliable
* Many material do not tolerate dry heat
- Methods of sterilization
d/ Characteristics of steam sterilization methods?
- Using steam autoclave heat
+) The steam entering the chamber from water reservoir displaces the air as it leaves the chamber
+) The combination of pressurization of the chamber, steam and a high temperature for a prolonged period has the ability to kill virtually all microorganisms
- Methods of sterilization
e/ Characteristics of Radiation sterilization methods?
◦ Non ionizing radiation in high dose
‣ UV rays: safety cabinets
‣ Infra red (IR) rays: pre-packed items (syringes)
◦ Clean, dry process
◦ Full exposure from all direction
◦ Gamma radiation
- Methods of sterilization
f/ What are the 2 types of Chemical sterilization methods?
gas and plasma
- Methods of sterilization
g/ Characteristics of steam sterilization methods?
- Using steam autoclave heat
+) The steam entering the chamber from water reservoir displaces the air as it leaves the chamber
+) The combination of pressurization of the chamber, steam and a high temperature for a prolonged period has the ability to kill virtually all microorganisms
- Methods of sterilization
g1/ What are advantages and disadvantages of steam autoclave?
1/ Advantage:
* good penetration
* hand pieces
* reliable
2/ Disadvantage:
* non stainless steel metal items corrode
* may damage plastic and rubber itemts
- Methods of sterilization
h/ Classification of chemical sterilization method
- Radiation - Gamma
- Gas
- Ethylene oxide
- Formalin
- What are guides for sterilization?
‣ Hand instruments:
* heat stable: sterilization
* non heat stable: cold sterilization, disinfection
‣ Hand-pieces: according to the manufacturer’s recommendation, if possible sterilisation
‣ Scaler: sterilisation
‣ Burs: careful,thoroughly cleaning,sterilizations
‣ Endodontic instruments: careful, thoroughly cleaning, sterilization (file, reamer, plugger….)
- What does asepsis mean?
- aims to destroy all existing contamination on the surface of equipment, on the skin or in the wounds
- What does antiasepis mean?
Procedure to prevent contamination
- We can achieve it with sterilization of all the equipment and materials we used by the surgery and keeping the strict behavioral rules at operating theatre
- What are requirements to sterilization?
1/ Cheap and easy to handle
2/ Efficient – reliably kills all pathogens in time
3/ Doesn’t destroy instruments/materials short
4/ Not damaging to human body
5/ Long-lasting
6/ Avoid human mistakes
- How is efficiency of sterilization controlled?
- Chemical indicator
– temperature - Biological indicator
– temperature, time, pressure
