Used as adjunct to mechanical plaque control.

Many vehicles may be used to deliver anti plaque agents such as:

MOUTH RINSES, TOOTHPASTES, SPRAY, IRRIGATORS, CHEWING GUM, VARNISHES.

Approaches to chemical supragingival plaque control:

1. ANTIADHESIVE: Prevention of attachment of bacterial biofilm.

2. ANTIMICROBIAL : by inhibition of bacterial proliferation and as bactericidal.

3. PLAQUE REMOVAL4. ANTIPATHOGENIC

1. Should eliminate only the pathogenic bacteria.

2. Prevent development of resistant bacteria.

3. Exhibit substantivity i.e. ability of an agent to bind to tissue surfaces and to be released over time to deliver an adequate dose of active principal ingredient the agent carries. (CHX gets adsorbed to oral tissues).

4. Safe to oral tissues at concentrations and dosages recommended.

5. Significantly reduce and gingivitis and prevent colonization of microorganisms.

6. Should not stain the teeth or alter taste.

Depending on the antimicrobial efficiency and relative substantitivity.

1st generation: decreases plaque scores by 20-50%, but efficacy is decreased by poor retention in the mouth. E.g. antibiotics , phenols etc.

2nd generation : 70-90%more effectively retained by oral

tissues and release slowly. E.g. Bisbiguanides

CHEMICAL PLAQUE CONTROL AGENTS

FIRST GENERATIONEg: antibiotics, phenol,quarternary ammonium compounds & sanguinarine

SECOND GENERATIONEg: Bisbiguanides,(chlorhexidine)

THIRD GENERATIONEg: delmopinol

1. Antibiotics: penicillin, vancomycin

2. Enzymes: proteases, lipase, dextranase

3. Bisbiguanide: chlorhexidine, alexidine

4. Quaternary ammonium compounds: cetylpyridinium chloride, benzalkonium chloride

5. Phenols and essential oils: thymol, triclosan

6. Natural products: sanguinarine7. Fluorides: sodium fluoride,

stannous F8. Metal salts: tin, zinc, copper9. Oxygenating agents: Hydrogen

peroxide10. Detergents: sodium lauryl

sulfate11. Amine alcohols: octapinol,

delmopinol

TRICLOSAN

ACT ON CYTOPLASMIC MEMBRANE

INDUCE LEAKAGE OF CELLULAR CONSTITUENTS

BACTERIOLYSIS

Triclosan is included in tooth paste to reduce plaque formation

Used along with Zinc citrate or co-polymer Gantrez to enhance its retention within the oral cavity

Triclosan delay plaque formation It inhibits formation of prostaglandins

& leukotrienes there by reduces the chance of inflammation

Cationic antiseptics & surface active agents Effective against gram positive organisms

MECHANISM OF ACTION

Positively charged molecule reacts with negatively charged cell membrane phosphates and thereby disrupts the bacterial cell wall structure

Eg: Benzanthonium chloride, Benzalleonium chloride and cetylpyredinium

It is a benzophenanthredine alkaloid It is most effective against gram –ve organisms Used in mouth rinse

Vancomycin,erythromycin,Niddamycin and Kanamycin

Due to bacterial resistance problems the use of antibiotics has been reduced

Considered to most effective antiplaque agents.

Second generation agents exhibiting substantivity and broad antimicrobial properties.

It is a cationic bisbiguanide

Effective against gram +ve, gram –ve organisms, fungi, yeasts and viruses

Exhibit antiplaque & antibacterial properties

CHX due to its dicationic nature, binds to enamel pellicle or tooth surface and salivary proteins. This adsorbed CHX is released of a period of time.

Mode of delivery of CHX: mouth rinse, gels, tooth paste, dental floss, and tooth picks.

Antimicrobial action and antiplaque action

1. ANTIMICROBIAL: a. at low concentration is bacteriostatic - positively charged chlorhexidine molecule will adhere to negatively charged bacterial cell surface. Integrity of cell membrane disrupted causing leakage of intracellular components.b. at high concentration is bactericidal – causes precipitation of bacterial cytoplasm so cell death.

Antibacterial action of chlorhexidineIt shows two actions

1. Bacteriostatic at low concentrations

Bacterial cell wall(-ve charge)

Reacts with +ve charged chlorhexidine molecule

Integrity of cell membrane altered

CHX binds to inner membrane phospholipids & increase permeability

Vital elements leak out & this effect is reversible

2. Bacteriocidal action increased concentration of chlorhexidine

Progressive greater damage to membrane

Larger molecular weight compounds lost

Coagulation and precipitation of cytoplasm

Free CHX molecule enter the cell & coagulates proteins

Vital cell activity ceases

cell death

ANTIPLAQUE ACTION: Prevents formation of acquired pellicle.

Blocks the acidic group of salivary glycoproteins which reduces their adsorption to hydroxyapetite.

Reduces the ability of bacteria to bind to tooth surface. Adsorption of CHX to bacterial capsule or glycocalyx and prevents them binding on to tooth surface.

CHX competes for Ca ions which are required for agglutination of plaque.

ADVERSE EFFECTS OF CHLORHEXIDINE

1. Brownish staining of tooth or restorations

2. Loss of taste sensation

3. Rarely hypersensitivity to chlorhexidine has been reported

4. Stenosis of parotid duct has also been reported

Enzymes has been used as active agents in antiplaque preparations

It is due to the fact that enzymes would be able to breakdown already formed matrix some plaques and calculus

Some are proteolytic and have bactericidal action

eg:Mucinase, mutanase, dextranase etc

Inhibits plaque growth and reduces gingivitis

Mechanism of action

Interfere with plaque matrix formation & also reduces bacterial adherence

It causes weak binding of plaque to tooth, thus aiding in easy removal of plaque by mechanical procedures

It is therefore indicated as a pre brushing mouth rinse

Adverse effect of delmopinol

1. Staining of tooth & tongue

2. Taste disturbances

3. Mucosal soreness & erosion

A disclosing agent is a preparation in liquid, tablet or lozenge from which contains a dye or other coloring agents

A disclosing agent is used for identifying bacterial plaque

When applied to the teeth, the agents imparts its colour to soft deposits but can be rinsed easily from clean tooth surface

IDEAL PROPERTIES

Intensity of colour Duration of intensity Taste Irritation to mucous membrane Diffusibility Astringent and antiseptic property

Agents used for disclosing plaquea. Iodine preparations

Skinners iodine solution Diluted tincture of iodine

b. Mercurochrome preparations Mercurochrome soln 5 Flavored mercurochrome disclosing solution

c. Bismark brownd. Mebromine. Erythrosinef. Fast greeng. Fluoresinh. Two tone solutionsi. Basic fuschin