STERILISATION EQUIPMENTS

STERILISATION
Main purposes :
To disinfect contaminated materials : sterilise the dental equipments

minimise the risk of transmission of micro-organisms

promote safe work environments
STERILISATION EQUIPMENT
MAIN
AUTOCLAVE
HOT AIR STERILISER
CHEMICAL AUTOCLAVES

OTHERS
HOT WATER STERILISER
GLASS BEAD STERILISER
CHEMICAL SYSTEM
UV

AUTOCLAVE

Temperature – the correct temperature must be maintained for the specified time

Cleanliness – the equipment must be clean to enable sterilisation

Circulation – the chamber must be designed to allow circulation around the equipment

Moisture – steam must be used in the sterilisation process.

AUTOCLAVE

best method for dental equipment

effective in killing bacteria and virus

safe for practicer

for all purpose (dental equipment)

simple --- safe time

high electricity voltage

relatively expensive

Temp : 121oC, 15 mnt or 134oC, 4 mnt

Jacket autoclave & non jacket autoclave

Components of the autoclave :
Boiler
Basket
Basket support
Drainage tap
Lid
Lid Clamps
Air Outlet valve
Safety valve
Temperature or pressure gauge


HOT AIR STERILISER
simple electric oven

alternative to autoclave

metals and glass instruments

instruments --- not corrode

take longer time

temp. 106oC (320o F), 2 hours


CHEMICAL AUTOCLAVES
formaldehid-alcohol vapor pressure
relatively fast
temp. 132oC (0.15-0.3 mpascal) for 20 mnt
dry method
not corrode or damage instuments
safety --- questionable
this methods are not in wide use
HOT WATER STERILISATION
the last choice
inefficient
cross contamination of instruments
soak the instuments in hot water
temp. 100oC, 20 mnt
corrode or damage the instruments

GLASS BEAD STERILISER
disinfecting endodontic instruments during use
glass bead put into ceramic pot and heated electrically
endodontic instrument inserted
not totally sterile --- handle (shank)
glass bead can be stuck to instrument surface --- transferred to root canal
replaced with salt
CHEMICAL SYSTEM
cold chemical sterilising
activated glutaradehid
the instruments soaked in a bath of solution for 8 hours
air trap in part of inst --- not sterile
Instrument must be clean
anti-corrosion buffering agent --- prevent the corrosion

ULTRAVIOLET LIGHTING
sterilisation for large space

can be installed in dental chairs

activated at night

UV radiation

good for instrument (cabinet etc) are illuminated directly
Specific sterilisation problem
Elevator
Hand istruments
Forceps and orthodontic pliers
Handpieces
Space disinfection