This document discusses various methods of disinfection and antisepsis used in dentistry. It describes different levels of disinfectants from low to high, including their mechanisms and examples like alcohol, phenolic compounds, aldehydes, and antiseptics. Specific chemicals discussed are ethanol, isopropyl alcohol, benzalkonium chloride, iodophor compounds, sodium hypochlorite, chlorhexidine, formaldehyde, and glutaraldehyde. The document provides an overview of common disinfection and antisepsis procedures in dentistry.

1. DISINFECTION
Prepared by : Parvathy Krishnan ( 3 rd Year BDS )
Roll No - 39

2. CONTENTS
• Introduction
• Methods
• Levels of disinfectant
• Antiseptics
• References

3. INTRODUCTION
Disinfection: “It is the term used for destruction of all pathogenic
organisms such as vegetative forms of bacteria ,mycobacteria,fungi
and viruses,but not bacterial endospores.”

4. METHODS
• Disinfection by cleaning
-Cleaning with a detergent and clean water removes almost all
pathogens.
• Disinfection by heat
- Heat is a simple and reliable disinfectant for almost anything
except living tissues.
- Cleaning with heat provides an excellent quality of disinfection
for a wide variety of purposes

5. • Disinfection by low temperature steam
-Most vegetative microorganisms and viruses are killed when exposed to
at a temperature of 73℃ for 20 minutes below atmospheric pressure.
-This makes it a useful procedure to make spoiled instruments safe to handle
prior to sterilization.
• Disinfection by chemical agents
-They are used to disinfect the skin of a patient prior to surgery and to
the hands of the operator.
-Disadvantages include that no chemical solution sterilizes the instruments
immersed in it.There is a risk of protecting tissue damage if residual solution is
carried into the wound.

6. LEVELS OF DISINFECTANT
• Low level disinfectant-Alcohol
-Ethanol and isopropyl alcohols are commonly used as antiseptics.
-Possess some antibacterial activity but they are not effective
against spores and viruses.
-Act by denaturing proteins.
-To have maximum effectiveness ,alcohol must have a 10 minutes
contact with the organisms.
-Instruments made of carbon steel should not be soaked in alcoholic
solutions as they are corrosive to carbon steel.
-Rubber instruments absorb alcohol thus their prolonged soaking
can cause reaction when material comes in contact with living tissue.

7. • Intermediate level- Phenolic compounds
-Phenolic compounds are used for disinfection of inanimate
objects such as walls,floors,furnitures.
-Their spectrum of activity includes lipophilic viruses ,fungi and
bacteria but not spores.Newer synthetic combinations are active
against hydrophilic viruses; hence these are approved by ADA
use as surface or immersion disinfectant.
-Phenolic compounds have unique action, which keeps them
active for longer period after initial application, known as
“Residual Activity”

8. • High level disinfectant –Aldehyde compounds
Formaldehyde
- Broad spectrum antimicrobial agent
- Flammable and irritant to the eye, skin and respiratory tract
- Has limited sporicidal activity
- Used for large heat sensitive equipment such as ventilators
and suction pumps excluding rubber and some plastics
- Not preferred due to its pungent odor and because 18 to 30
hours of contact is necessary for cidal action.

9. Glutaraldehyde
-Toxic, irritant and allergenic
- A high level disinfectant
-Active against most vegetative bacteria, fungi and bacterial spores
- Frequently used for heat sensitive material
- A solution of 2 percent glutaraldehyde (Cidex), requires immersion of 20
minutes for disinfection; and 6 to 10 hours of immersion for sterilization
- Safely used on metal instruments, rubber, plastics and porcelain
- Activated by addition of sodium bicarbonate but in its activated form, it
remains potent only for 14 days.

10. ANTISPETICS
“Antiseptic is a chemical disinfectant that can be diluted sufficiently to be
safe for application to living tissues like intact skin,mucousmembranes
and wounds “
Alcohols
-Two types of alcohols are used—ethyl alcohol and isopropyl alcohol.
- Their benefit is derived primarily in their cleansing action.
- Alcohols must have a prolonged contact with the organisms to have an
antibacterial effect.
-Ethyl alcohol is used as 70% as skin antiseptic.
- Isopropyl alcohol is used in 60 to 70% for disinfection of skin.

11. • Aqueous Quarternary Ammonium Compounds
-Benzalkonium chloride (Zephiran) is the most commonly used antiseptic. It
well-tolerated by living tissues.
• Iodophor Compounds
- Used for surgical scrub, soaps and surface antisepsis.
-These compounds are effective against most bacteria,viruses
and fungi.
-Usually effective within 5 to 10 minutes.
- Discolor surfaces and clothes.
-Iodine is complexed with organic surface active agents such as
polyvinyl-pyrrolidine (Betadine, Isodine).
-Their activity is dependent on the release of iodine from the complex.
-Concentrated solutions have less free iodine. Iodine is released as the
solution is diluted.

12. • Chloride Compounds
- Commonly used are sodium hypochlorite and chlorine dioxide.
-Sodium hypochlorite has rapid action.
- A solution of 1 part of 5 percent sodium hypochlorite with 9 parts of water
used.
- Chlorous acid and chlorine dioxide provide disinfection in 3 minutes.
• Diguanides
-Chlorhexidine is active against many bacteria
-Gets inactivated in the presence of soap, pus, plastics, etc.
-Mainly used for cleaning skin and mucous membrane.
-As a 0.2 percent aqueous solution or 1 percent gel, it can be used for
suppression of plaque and postoperative infection

13. REFERENCES
• Sturdevant's Art & Science of Operative Dentistry,2 nd South Asian Edition
• Clinical Operative Dentistry: Principles and Practice,Ramya Raghu,2 nd
edition
• Textbook of operative dentistry , Nisha Garg ,3 rd Edition

14. THANK YOU