This document discusses disinfection, including ideal characteristics of disinfectants, common terminology, various disinfectants and their uses, recommended concentrations, and recent advancements. It provides details on types of disinfectants such as alcohol, aldehydes, phenols, halogens, metallic salts, dyes, and gases. It also discusses recommended concentrations and recent developments, including disinfectants used for COVID-19 and techniques for disinfecting surfaces, dental casts, impression trays, and instruments in dental settings.

1. DISINFECTION
Presented by- Dr. Smaraki Mahapatra
MDS 1ST year(orthodontics)

2. CONTENTS
1. Introduction
2. Ideal Characteristics
3. Terminologies
4. Various Disinfectants and its uses
5. Recommended concentrations of
disinfectants
6. Recent advancements
7. Conclusion
8. References

3. DISINFECTION
1. It means the destruction of all
pathogens or organisms capable of
producing infections but not necessarily
spores.
2. All organisms may not be killed but the
number is reduced to a level that is no
longer harmful to health.

4. IDEAL CHARACTERISTICS
1. Broad spectrum
2. High penetration power and
quick action
3. Stable and effective in acidic
and alkaline conditions
4. Not toxic if absorbed in to
circulation
5. Be safe and easy to use

5. TERMINOLOGIES
ANTISEPTIC :-
Chemical destruction of
Vegetative pathogens on living tissue.
Joseph Lister-
father of 1st
antiseptic
surgery

6. BACTERICIDAL AGENTS-
Chemical agents which are
able to kill bacteria

7. BACTERIOSTATIC AGENTS-
Only prevents the
multiplication of
bacteria which may
however remain
alive.

8. DECONTAMINATION-
The process of
rendering an article or
area free of danger
from contaminants,
including microbial,
chemical, radioactive
and other hazards.

9. SANITIZATION :-
Lowering microbial counts on eating
and drinking utensils to safe levels.

10. VARIOUS DISINFECTANT
AND ITS USES

11. ALCOHOL
Mechanism of Action-
Denaturation
of bacterial proteins.
 Ethyl alcohol and
Isopropyl alcohol are
the most frequently used.
Use:-
 75% alcohol
used as hand sanitizer.

12. ALDEHYDES
A- Formaldehydes-
 In aqueous solution it acts as
a bactericidal and
sporicidal.
 Active against gram-ve
bacteria, spores,
viruses (Hb, HIV)
fungi.

13.  Aqueous solution-
formalin (37%)- 10% formalin
+ 0.5% Na tetraborate used
to clean metal instruments
eg- dialysis instruments,
endoscopes
 Used to preserve
anatomical specimens.

14.  Gaseous form-
 Fumigation of wards, corridors, ICU, laboratories
 The gas is irritant and toxic but can be nullified
by exposure to ammonia vapor after disinfection
has been completed.

15. B- Glutaraldehyde/ Cidex
(2% alkaline NaHCO3)
 High level disinfectant
 Active against tubercle
bacteria, fungi, viruses
 Used for face masks,
metal instruments
 It has no deleterious
effect on lenses of
cytoscopes/ brochoscopes

16. PHENOLS
 Acts by cell membrane
damage thus releasing
cell contents & cause lysis
 Commonly found in
mouthwashes, scrub soap
 Also decontamination
of hospital, labs,
non-critical medical items.

17.  Lysol and cresol are active against a wide
range of organisms.
 But toxic to humans.
 The combination of these are used against
pyogenic cocci in surgical and neonatal units
in hospitals.
 Chlorhexidine is relatively nontoxic skin
antiseptic.

18. HALOGENS
A- Chlorine Compounds-
 Bleaching powder or
hypochlorite solution
used mainly for
HIV infected material.
 Water supplies, swimming
pools use chlorine for
disinfection.

19. B- Iodophors and
Iodine-
 Active against bacteria,
spores, fungi.
 Suitable for skin
preparations, mouthwash
and surgical scrub.

20. METALLIC SALTS
 Salts of heavy
metals have toxic effect
on bacteria.
 Salts of Copper,
Silver,mercury are used
as disinfectants.

21. DYES
 Two groups i.e aniline and acridine dyes
are used as skin and wound antiseptics.
 Both are bacteriostatic.
 Aniline dyes are green and active against
gram +ve bacteria.
 Are inhibited by organic material such as
pus.

22.  Acridine dyes are effective against gram
+ve bacteria
 Very little affected by organic matter
 Can be used in moist environment hence
used in clinical medicine.
 They impair the DNA complexes and hence
kill the reproductive capacity of the cell.

23. GASES
Ethylene Oxide(ETO)-
 It is a colourless liquid with a boiling point of
10.7 degree celcius.
 Uses as a disinfectant but presents toxicity to
human beings – carcinogenicity and
mutagenicity.
 Used for sterilizing heart-lung machines, sutures,
dental equipments
 Not suitable for rooms as is inflammable

24. Formaldehyde gas-
 This is widely employed for fumigation of
operation theatres and other rooms
 After sealing windows, formaldehyde gas is
generated by adding 150 gm of KMnO4 to 280
ml formalin
 During its use, doors should be sealed for 48
hours

25. DENTAL SURGERY
PERSPECTIVE
Gigasept which contains
succindialdehyde and
dimethoxytetrahydrofuran
are used for disinfection
of plastic and rubber materials
eg dental chair

26. RECOMMENDED
CONCENTRATION OF
DISINFECTANTS

27. DISINFECTANT CONCENTRATION
Ethyl alcohol 70%
Glutaraldehyde 2%
Lysol 2.5%
Savlon(Chlorhexidine and
cetrimide)
2%,5%
Dettol(chloroxylenol) 4%
Bleaching powder(calcium
hypochlorite)
14 gm in 1 litre of water
Betadine(Iodophore) 2%

28. DISINFECTANT –RECENT
ADVANCEMENT

29. Various disinfectants
used during covid- 19
 Sodium hypochlorite-0.05%
 Hydrogen peroxide-0.5%
 Alcohol-75%

30. SODIUM HYPOCHLORITE AND
HYDROGEN PEROXIDE

31. SANITIZER

38. Disinfection of dental casts
Dental casts to be
disinfected in 1:10 dilution
of sodium hypochlorite or
an iodophor , then rinse
and stored for atleast 24
hours.

42. Disinfection of alginate
impresssion trays
 Methods:-
1. Spraying
2. Immersion
3. Iodophors, sodium
hypochlorite(1:10 concentration)
4. Phenol, formaldehyde,
glutaraldehyde.

43. Disinfection of Sharp
,endodontic, sutures
instruments
1. After autoclaving of sharp instruments, it is
to be kept
In activated in solution of Cidex(2%
glutaraldehyde).
2.Diamond or carbide burs after use are placed
in Cidex solution and sporicidin solution for 10
minutes.
3. Soak the suture materials full for 10 minutes
in
10% providone iodine solution and then rinse
with sterile water.

50. Detergents for surface
disinfection
 Detergents(EPA registered used for
disinfecting non-critical patient care
equipments.
 It can also be used for surface
disinfection for reducing microbial
load.

51. Disinfection of computer
keyboards
1. Increased use of computers in patient areas
has led to contamination of keyboards as
reservoir of pathogens.
2. Disinfectants used:-
3 quaternary ammonium
compounds, 70% isopropyl alcohol, phenolic,
chlorine.
3. As present , recommended that keyboards be
disinfected daily(for 5 seconds) .

53. CONCLUSION
1. Sterilization and disinfection are costly and time
consuming process.
2. However, it is an essential in all health care
facilities.
3. It depends on the ethics of instrument users.
4. Users should keep in mind that contaminated
instrument present risk to patient as well as the
user itself.

54. REFERENCES
 C P Baveja. Text book of Microbiology ;6th
edition.
 Ananthanarayan and Paniker. Text book of
Microbiology;8th edition.
 Rutala WA,Weber DJ.New disinfection and
sterilization methods . Emerg Inf Dis
2001;7:348.
 Internet