A brief presentation on the topic of disinfection and sterilization for dental students. in this presentation, we tried to cover the Disinfection process, disinfectants, antiseptic solution, sterilization techniques, cross-infection control, and management of needle stick injury.

1. DISINFECTION &
STERILIZATION
DR. OSAMA MUSHTAQ
BDS, FCPS (OMFS)

2. Dr. Osama Mushtaq
FCPS (OMFS)
INTRODUCTION TO TERMININOLOGIES
• CLEANING;
A process which removes visible
contamination but not
microorganisms.
Manual or Mechanical cleaning should
be performed in a designated area,
immediately after the procedure.
Quick Cleaning removes blood or
debris much easier & can minimize
instrument staining, corrosion or
pitting.

3. Dr. Osama Mushtaq
FCPS (OMFS)
TERMINOLOGIES
• DISINFECTION;
A process which reduces number of
microorganisms to an acceptable level
but may not inactive some viruses &
bacterial spores.
DISINFECTANT;
A Chemical Substance used on non vital
objects for the purpose of disinfection.

4. Dr. Osama Mushtaq
FCPS (OMFS)
TERMINOLOGIES
• ANTISEPTIC;
It’s a chemical applied to living tissues to reduce number
of microorganisms.

5. Dr. Osama Mushtaq
FCPS (OMFS)
TERMINOLOGIES
• STERILIZATION;
A Process of destruction or removal of all forms of microbes.

6. CLEANSING OF
INSTRUMENTS
CLEANING DISINFECTION STERILIZATION

7. Dr. Osama Mushtaq
FCPS (OMFS)
DISINFECTION
• A process which reduces number of microorganisms to
an acceptable level but may not inactive some viruses &
bacterial spores.
MECHANISM OF ACTION
1- Coagulation of Bacterial proteins
2- Alter properties of bacterial cell wall
3- Binding of sulfahydryl groups essential for an enzyme
action.
4- Competition with essential substrates for the
important enzymes in bacterial cell.

8. Dr. Osama Mushtaq
FCPS (OMFS)
METHODS OF DISINFECTION
•By Cleaning with detergent & Hot water
•By Heat
•By low temperature steam at 73˚C for 20
mins at below atmospheric pressures
•By boiling water
•By chemical agents to disinfect patient`s
skin & operator`s hands.

9. Dr. Osama Mushtaq
FCPS (OMFS)
DISINFECTANT
• A Chemical Substance used on non vital objects for the purpose of
disinfection.
DISINFECTANTS/CHEMICAL AGENTS FOR DISINFECTION
ALDEHYDES;
1- Formaldehyde for ventilators & suction, limited sporicidal activity.
2- Glutaraldehyde, high level disinfectant
2.4% glutaraldehyde (cidex) requires immersion for 10 mins
DIGUANIDES;
For cleaning skin & mucus membrane

10. Dr. Osama Mushtaq
FCPS (OMFS)
DISINFECTANT
• 0.5% Chlorhexidine in 70% alcohol
• CHX with Cetrimide (cetavlon/ Savlon)
• 4% CHX with detergent (hibiscrub) for
preoperative scrub
• Halogens ( hypo chlorites)
• Phenolic Compounds;
for disinfection of innate objects

11. Dr. Osama Mushtaq
FCPS (OMFS)
LIMITATIONS FOR DISINFECTANTS
• Inactivation by blood, pus, debris
• Concentration
• Not stable on dilute forms
• Appropriate period of exposure to
agent
• Neutralization by soaps &
detergents

12. Dr. Osama Mushtaq
FCPS (OMFS)
LEVELS OF DISINFECTION
• HIGH LEVEL DISINFECTION;
-To destroy all microorganisms except
bacterial spores
-Glutaraldehyde 2% 45 mn
-Hydrogen peroxide 6% 20 mn
-Wet Pasteurization 75˚C 30 mn
-Chlorine 1000 ppm 20 mn
- Ethyl alcohol 10 mn
- Isopropyl alcohol 10 mn

13. Dr. Osama Mushtaq
FCPS (OMFS)
HIGH LEVEL DISINFECTION
• Chlorine 1000 ppm 10mn
• Phenolic germicidal solution 10 mn
• Iodophor germicidal solution 10 mn

14. Dr. Osama Mushtaq
FCPS (OMFS)
INTERMEDIATE LEVEL DISINFECTION
• Inactivates Mycobacterium tuberculosis, vegetative bacteria,
most viruses, most fungi but not bacterial spores
- Ethyl alcohol 10mn
- Isopropyl alcohol 10mn
- Chlorine 1000 ppm 10 mn
- Phenolic germicidal solution 10 mn
- Iodophor genicidal solution 10 mn

15. Dr. Osama Mushtaq
FCPS (OMFS)
LOW LEVEL DISINFECTION
• Kills most vegetative bacteria, most fungi, viruses but resistant
to mycobacteria & bacterial spores
- Ethyl alcohol 10mn
- Isopropyl alcohol 10mn
- Chlorine 1000 ppm 10 mn
- Phenolic germicidal solution 10 mn
- Iodophor genicidal solution
- Quaternary germicidal solution 10 mn

16. Dr. Osama Mushtaq
FCPS (OMFS)
ANTISEPTICS
-A chemical disinfectant diluted for applying on living
tissues
-Less toxic than disinfectants
-ANTISEPTIC AGENTS;
Alcohols
Aqueous quaternary ammonium compounds
Hexachlorophene
iodophor compounds

17. Dr. Osama Mushtaq
FCPS (OMFS)
MECHANISM OF ACTION OF ANTISETICS
1- Coagulation of Bacterial proteins
2- Alter properties of bacterial cell wall
3- Binding of sulfhydryl groups essential
for an enzyme action.
4- Competition with essential substrates
for the important enzymes in bacterial cell.

18. Dr. Osama Mushtaq
FCPS (OMFS)
FACTORS AFFECTING ANTISEPTIC
ACTION
• INCREASES WITH RISE IN CONCENTRATION
• TEMPERATURE
• DURATION OF CONTACT

19. Dr. Osama Mushtaq
FCPS (OMFS)
How to ensure Sterilization ??
• High quality sterilization equipments and
maintenance.
• Correct operation of equipments.
• Comprehensive operator training.
• Weekly use of biological indicators.

20. Dr. Osama Mushtaq
FCPS (OMFS)
STERLIZATION
• A Process of destruction or removal of all forms of
microbes
• PRINCIPLES OF STERLIZATION;
• Instruments thoroughly cleaned before sterilization
• Sterilizing agent (heat, steam/gas) should come in
contact with each surface of an item.
• Sterilizing equipment regularly serviced & managed.

21. Dr. Osama Mushtaq
FCPS (OMFS)
Preparations for Sterilization
• Pre cleaning of instruments.
• Scrubbing with soap and water or ultrasonic
device.
• Ultrasonic cleaner
( Best possible way )

22. Dr. Osama Mushtaq
FCPS (OMFS)
Methods of sterilization
•Steam under pressure.
•Chemical vapor under pressure.
•Dry heat sterilization.

23. Dr. Osama Mushtaq
FCPS (OMFS)
Verification of sterilization
• Sterilization monitors includes;
• Mechanical indicators : machines that record
temperature
• Biological indicators : consists of strips with live
resistant bacterial spores ( bacillus spores )

24. Dr. Osama Mushtaq
FCPS (OMFS)
Verification of sterilization
• Chemical indicators : chemicals that melts and changes
color.
e.g. Autoclave tapes, temperature tubes, integrators.

25. Dr. Osama Mushtaq
FCPS (OMFS)
Classification of instrument
sterilization
Critical Instruments Semi critical instruments Non critical items
Which touches sterile areas of
the body and penetrate the oral
mucosa
Which touches the mucous
membrane but do not penetrate.
Which do not come in contact with
oral mucosa

26. Dr. Osama Mushtaq
FCPS (OMFS)
Critical Instruments

27. Dr. Osama Mushtaq
FCPS (OMFS)
Semi Critical instruments

28. Dr. Osama Mushtaq
FCPS (OMFS)
Non critical items

29. Dr. Osama Mushtaq
FCPS (OMFS)
STERILIZATION
Three Most used Methods for sterilization in dentistry
• Steam under pressure
• Chemical vapors under pressure
• Dry heat sterilization

30. Dr. Osama Mushtaq
FCPS (OMFS)
Steam/Moist Heat under pressure
(Autoclave)
• Most efficient method of sterilization
a) High penetrating capacity
b) Gives large amount of heat to surface in
contact
Three major factors are:
Temperature;121 Degrees Celsius (249° F)
• Pressure; 15 psi
• Time: 15 – 40 minutes

31. Dr. Osama Mushtaq
FCPS (OMFS)
Steam/Moist Heat under pressure
(Autoclave)
Advantages:
• Rapid and effective
• Effective for sterilizing clothes, gowns, cotton rolls,
rubber gloves, suture materials, suture materials, lab
equipments, surgical dressing packs, surgical
instruments, and towels pack.
Disadvantages:
• Rusting , Blunting and Corrosion of sharp instruments
, Dulling of instruments, damage to rubber goods.

32. Dr. Osama Mushtaq
FCPS (OMFS)
Chemical Vapors sterilization
• Based on factors of heat , pressure and chemical vapors.
• Chemicals include alcohol, acetone, ketones , formaldehyde.
• 132 Degree Celsius for 20 minutes.
Advantages:
• Less time taking cycle.
• No corrosion of carbon steel instruments.
Disadvantages:
• Bad odor from chemicals.

33. Dr. Osama Mushtaq
FCPS (OMFS)
Dry Heat sterilization
-Alternate method for sharp instruments
-Temperature;160 Degree Celsius ( 320º F )
-Time = 2 hours
-Two methods;
Hot air oven
Glass beads
-MECHANISM OF ACTION:
Its basic action is dehydration and oxidation of microorganisms.

34. Dr. Osama Mushtaq
FCPS (OMFS)
Dry Heat Sterilization
ADVANTAGES:
Don’t rust instruments.
DISADVANTAGES;
Less penetration
Less effective
Time consuming

35. Dr. Osama Mushtaq
FCPS (OMFS)
BARRIER TECHIQUES

36. Dr. Osama Mushtaq
FCPS (OMFS)
GLOVES
• Protects patient and health care
workers.
• ADA recommends single use of
gloves.
• Double gloves indicated for HIV
or HBV or Herpes Patient.

37. Dr. Osama Mushtaq
FCPS (OMFS)
HAND WASHING
•Done before
wearing
Gloves.
•Antimicrobial
hand washes
to be used.

38. Dr. Osama Mushtaq
FCPS (OMFS)
FACE MASK
•Prevent inhalation
of aerosols
generated by high
speed hand
pieces and air
syringes.

39. Dr. Osama Mushtaq
FCPS (OMFS)
Eye Glasses
• Highly Beneficial
• Prevents contact with eye by
aerosol infection.
• Eye wear to cleaned with
disinfectant after every patient.
• Herpes infection of eye and Hep B
may occur due to contact with eye.

40. Dr. Osama Mushtaq
FCPS (OMFS)
Clothing
• Reusable or disposable gowns
recommended.
• Labs coats or uniforms with long sleeves.
• Head covers recommended in surgeries
• Gowns to be changed daily.
• Laundering at 60 - 70°C with bleach
followed by machine drying recommended.
• Shoes to be changed at Office, operation
theater.

41. CLOTHING

42. Dr. Osama Mushtaq
FCPS (OMFS)
Procedural Barriers
•Rubber dam
•High speed
evacuation
•Paper or aluminums
wraps.
•Radiographic films.

43. PROCEDURAL BARRIERS

44. Needle stick injury
Sharp injury
Stop the procedure
Injury assessment ( How deep is it?
source of injury, any blood on tip)
Wash with Tap water
Encourage bleeding ( No scrubbing,
No sucking )

45. Assess patient`s
Risk factors
( Hep B , Hep C ,
HIV , Drugs )
Identify Immune
system of doctor/ Staff
Protected
• Antibody Titer ˃100 IU/L
• Antibody Titer 10-99 IU/L
• Last Dose ˂ 2 years
Incomplete Protection
• Antibody Titer 10-99 IU/L
• Last Dose ˃2 years
• Rx; Booster Dose of HBV
• Follow Up
Unprotected
• Antibody Titer ˂10 IU/L
• No History of Immunization
• Rx; Booster Dose of HBV
• Immunoglobulin of Hep B within
48 Hrs
• Follow Up (3 weeks, 3 Months, 6
Months)

46. Schedule for Hepatitis B Vaccine