This document summarizes information about chlorhexidine (CHX), a commonly used chemical plaque control agent. It discusses CHX's bacteriostatic and bactericidal properties, mechanisms of action, formulations, efficacy, advantages such as substantivity, recommended usage, and potential side effects. CHX is considered the gold standard due to its strong antibacterial activity against both gram-positive and gram-negative bacteria and its ability to bind to tooth surfaces through its dicationic nature, prolonging its effects for up to 12 hours with a single rinse.

1. -GURVINDER MITTAL
BDS Final Year

2. INTRODUCTION
Microbial plaque is the major etiology of periodontal
diseases. Plaque control is the regular removal of mirobial
plaque and the prevention of its accuulation on the teeth
and adjacent gingival surfaces.

3. DENTAL PLAQUE
DENTAL PLAQUE is a highly specific variable structural
entity formed by sequential colonization of
microorganisms on the tooth surface, epithelium and
restorations.
The natural physiological forces that clean the oral cavity
are insufficient in removing dental plaque.

4. CHEMICAL PLAQUE CONTROL AGENTS
FIRST GENERATION
Eg: antibiotics, phenol,quarternary ammonium compounds & sanguinarine
SECOND GENERATION
Eg: Bisbiguanides,(chlorhexidine)
THIRD GENERATION
Eg: delmopinol

5. Ideal requisites
Should decrease plaque & gingivitis
Prevent pathogenic growth
Should prevent development of resistant bacteria
Should be biocompatible
Should not stain teeth or alter taste
Should have good retentive properties
Should be economic

6. CHLORHEXIDINE
CHLORHEXIDINE is a GOLD STANDARD IN
CHEMICAL PLAQUE CONTROL with outstanding
bacteriostatic and bactericidal properties.
Effective on both gram positive and gram negative
bacteria, although it is less effective with some gram
negative bacteria

7. Chemical structure:
Chlorhexidine is a symmetrical molecule consisting
of FOUR CHLOROPHENYL RINGS and
BISGUANIDE GROUPS connected by a CENTRAL
HEXAMETHYLENE BRIDGE.
The compound is strongly base & dicationic at ph
levels above 3.5 with positive charges on either side of
hexamethylene bridge.
It is the “dicationic nature” of chlorhexidine making it
extremely intractive with anions, which is relevant to
its efficacy.

8. Available in three forms:
Digluconate- most commonly used & water
soluble
Acetate- water soluble
Hydrochloride salts- sparingly water soluble

9. Mechanism of action:
Antimicrobial activity:
CHX shows different effects at different concentrations
The agent is bacteriostatic, whereas at higher concentration
it is bactericidal
cationic CHX molecule+ negatively charged bacterial cell wall
Instant adsorption of CHX to Phosphate containing compounds
CHX binds with the phospholipids in the inner cell membrane
causing cell wall integrity
Leakage of the lesser molecular weight components viz. potassium
ions
[This is the sub lethal stage of CHX. The action can be reversed. This
marks the bacteriostatic property of CHX. If the conc. Is increased and
the action continues, the CHX becomes bactericidal in nature]

10. Intracellular coagulation
Slows down leakage of intracellular
components
Cytoplasmic coagulation
Irreversible cell damage [bactericidal]

12. • Antiplaque activity:
Three mechanism for inhibition of plaque by CHX:
1. The effective blocking of the acidic group of
salivary glycoproteins will reduce their
adsorption to hydroxyapatite and formation of
acquired pellicle
2. The ability of bacteria to bind to tooth surface
may be reduced by adsorption of CHX to the
extracellular polysaccharides of their capsule
3. The CHX may compete with calcium ions for
acidic agglutination factors in plaques

13. What makes it so unique?
Its long lasting bacteriostatic action, also termed
as ‘substantivity.’
Its action lasts for about 12 hours in the oral cavity
after a single rinse
The dicationic CHX molecule, attaches to the
tooth surface (pellicle) by one cation, to the
bacteria attempting to colonize the tooth surface
with the other. This is called the ‘Pin-Cushion
Effect’
This prolongs the CHX action

14. Uses:
1. As an adjunct to oral hygiene
2. Post oral surgery including periodontal surgery or root planing
3. In patients with inter maxillary fixation.
4. For oral hygiene & gingival health in physically & mentally
handicapped
5. Medically compromised individuals predisposed to oral
infections
6. High caries risk patient
7. Recurrent oral ulceration
8. Removable & fixed orthodontic wearers
9. Treatment of denture stomatitis and dry socket
10. As an immediate prophylactic rinse in the prevention of post-
extraction bacteremia

15. Adverse effects:
a) Extrinsic staining
b) Alteration in taste perception
c) Oral mucosal erosion
d) Enhanced supragingival calculus formation
e) Parotid gland swelling (stenosis of the parotid)
f) Overdosage: ingestion of 1 or 2 ounces of CHX
oral rinse by a small child might result in gastric
distress, including nausea or signs of alcohol
intoxication.

16. Dosage & administration:
Recommended use is twice daily oral rinsing for 30
seconds.
Usual dosage is of 0.12-0.2 percent of 15ml (1
tablespoon) of undiluted chlorhexidine oral rinse.
Patient should be instructed not to rinse with
water or brush teeth or eat immediately after CHX
oral rinse.
CHX should not be ingested and should be
expectorated after rinsing.

17. The chlorhexidine preparations compared were a 0.12%
concentration used at a 15 ml dose for a rinsing time of 30 seconds
and a 0.2% concentration used at a dose of 10 ml for 60 seconds.
After 72 hours, the plaque index (PI) from all volunteers was
recorded at 6 sites per tooth. All participants received a
questionnaire to evaluate their perception of the mouthrinses.
Results: After 72 hours, the 15 ml/30 second/0.12% CHX group
had a mean whole mouth PI of 1.65 (SD 0.31) compared with a
mean PI of 1.60 (SD 0.40) for the 10 ml/60 second/0.2% CHX
group. The difference in plaque scores between the groups was not
statistically significant. Results from the questionnaire showed no
significant difference between the groups for taste perception,
duration of taste, alteration in taste, or perceived plaque
reduction; however, the panelists preferred the shorter rinsing
time of 30 seconds and, for this parameter, the difference was
statistically significant (P = 0.048).
Conclusions: The results of this short-term study showed that
there was no statistically significant difference between both
commercially available CHX mouthrinses with respect to plaque
inhibition, although both differed in concentration and rinsing
time. The subject preference phase of the study indicated that the
shorter rinsing time of 30 seconds was favored.

18. Should not be used immediately after the toothbrushing
WHY….?
Sodirm lauryl sulphate appears to adversely affect the
retention of chlorhexidine and its plaque inhibiting
action. Rinsing with chlorhexidine should therefore not
be performed in combination with tooth brushing.
The chlorehexidine should be used 0.5 to 2 hrs after the
toothbrushing.

19. Chlorhexidine products:
Mouth rinse- aqueous/ alcohol solutions of 0.2%
[Peridex, Periogard, Periosol]
Gel [corsodyl dental gel]
Sprays [Hibispray]
Tooth pastes
Varnishes
Chewing gums
Periodontal dressings
Subgingival plaque control [Periochip]

20. THANK YOU