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ISHIK UNIVERSITYFACULTY OF DENTISTRY

Oral Pharmacology
2016-2017

Dr. Esra Tariq Bayrakdar

Pharmacist (M.Sc.)
2017-Oral Pharmacology

Mouth Diseases

Oral and Maxillofacial Pathology is a specialty of dentistry concerned with the non-surgical treatment of conditions occurring in the head and neck region.
Patients with mouth diseases can be seen by a variety of doctors, but
oral and maxillofacial pathology is the only specialty of dentistry or medicine that concentrates specifically on the diagnosis (both clinically and microscopically) and non-surgical treatment of conditions that affect the mouth.
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Mouth Diseases

General dentists usually treat tooth problems while specialists called periodontists treat periodontal (gum) diseases.
Although problems caused by cavities and gum disease are the most common mouth disorders, a wide variety of other diseases can affect the mouth and adjacent tissues.


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Some of the conditions that would be evaluated by an oral pathologist would include:

burning mouth syndrome
canker sores (an immune-mediated condition)
cold sores (a herpes virus infection)
geographic tongue (an inflammatory disorder)
leukoplakia
lichen planus (another immune-mediated condition).
smokeless tobacco keratosis (in most cases, a harmless callous-type change)

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The types of conditions seen by oral and maxillofacial pathologists include viral and fungal infections, tumors of the soft tissues of the mouth as well as the jawbones, autoimmune diseases and disorders of the salivary glands.

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Antiseptics and Disenfectants

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Antiseptics are used on living surfaces.
Disinfectants are used for inanimate objects.
The practical distinction of these two agents is on the basis of a growth inhibiting or direct lethal action.
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In dentistry, they are used for sterilization of certain instruments and prevention and treatment of dental plaque and peridental diseases.
They are also used in root canal therapy (RCT), treatment of acute necrotizing gingivitis and other infective oral conditions. Antiseptics and disinfectants are also used as ingredient in various dentifrices.

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Germicide covers these two category. Potency of germicide is generally expressed by its “phenol coefficient or Rideal Walker (RW) coefficient” – “which is the ratio of the minimum concentration of the test drug required to kill a 24 hour culture of B. typhosa in 7.5 minutes at 37.5°C to that of phenol (as standard) under similar conditions.”
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Factors which Modify the Activity ofGermicides

1)Temperature & pH.
2)Period of contact with the microorganisms.
3)Nature of microbes involved.
**Spectrum of activity of majority of antiseptic disinfectants is wide reflecting non selectivity of action.
However, some are selective e.g. hexachlorophene, chlorhexidine, quarternary ammonium antiseptics, gentian violet, acriflavine are more active for gram +ve than gram –ve. Silver nitrate is highly active against gonococci and benzoyl peroxide against P. acnes.
4)Size of inoculum.
5)Presence of blood, pus & other organic matter.
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Mechanism of Action (Cidal orInhibiting Action)

i. Oxidation of bacterial protoplasm.

ii. Denaturation of bacterial proteins including enzymes.
iii. Detergent like action increasing permeability of bacterial membrane.

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Classification
i. Phenol derivatives.
ii. Oxidizing agent.
iii. Halogens.
iv. Biguanides.
v. Quarternary ammonium compounds.
vi. Acids.
vii. Metallic salts.
viii. Dyes.
ix. Furan derivatives.
x. Alcohol.
xi. Aldehydes.
xii. Soaps.
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PHENOL DERIVATIVES
Used as disinfectants
Phenol (carbolic acid): Acts by denaturing bacterial proteins.
Methylphenol (cresol; LYSOL): 3-10 times more active.
Resorcinol: 1/3 as potent as phenol (used both as an antiseptic/disinfectant). Used as antiseptic.
Hexyl-resorcinol: More potent. Used as mouth wash, lozenges & as antifungal.
Chloroxylenol:
– 4.8% sol. (DETTOL): Used for surgical antisepsis.
– 1.0% sol. (DETTOLIN) used as mouth washes, 0.8% cream & soap; 1.4% lubricating obstetric cream (for vaginal examination).
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Hexachlorophene:

Act by inhibiting bacterial enzyme and in high concentration cause bacterial lysis.
Incorporated in soap & other cleansing antiseptics. Also acts as deodorant.
– Highly active against gram +ve microorganisms.
Phenol is used to disinfect urine, faeces, pus, sputum of patients and sometime included in antipruritic preparation because of its mild anaesthetic action.
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OXIDIZING AGENTS

1. Potassium permanganate (KMnO4):
Water soluble purple crystals.
Liberates oxygen which oxidizes bacterial protoplasm.
Potassium permanganate (KMnO4) is used as Condy’s lotion (1 : 4,000 to 1:10,000 solution).
As antiseptic:
– Used for gargels, irrigating cavities, urethra & wounds.
– Higher concentration cause burns & blistering.
As disinfectants:
– To disinfect water (well, ponds) & for stomach wash in alkaloidal poisoning (except atropine & cocaine which are not efficiently oxidized).
– Not suitable for surgical instruments (promotes rusting).


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2. Hydrogen peroxide (H2O2):

Used as antiseptic.
Removes slough, ear wax etc.
Used in cosmetic preparation.
As gargels.
Potency loses on keeping and not much used.
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3. Benzoyl peroxide (PERSOL 2.5, 5.0% gel, 10% cream):

Used in acne.
Gradually liberates oxygen (in the presence of water) which kills bacteria, specially anaerobic.
Mild irritant to skin.
Can cause dryness of skin, edema etc.
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HALOGENS

1. Used as disinfectants:
Chlorine: Highly reactive element & potent germicide.
2. Used as antiseptic:
Iodine: Act by iodinating and oxidizing microbial protoplasm.
Povidone (polyvinyl pyrrolidone):
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BIGUANIDES
Chlorhexidine:
– Having high antiplaque activity.
– Used as antiseptic.
– Nonirritating antiseptic that disrupts bacterial cell membrane.
– More active against gram +ve bacteria
– Used for surgical scrub, mouthwash, neonatal bath & general skin antiseptic.
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QUARTERNARY AMMONIUM ANTISEPTICS(CATIONIC)

Act by altering permeability of cell membranes.
Soaps (being anionic) neutralise their action while alcohol potentiates.
Non-irritating & mild keratolytic.

Cetrimide, Benzalkonium chloride.

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ACIDS

Boric acid:
– Bacteriostatic & weak antiseptic.
– 4% sol.: Used for irrigating eyes, mouth washes, douche etc.
– Boroglycerine paint (30%): Used for stomatitis & glossitis.
– 10% ointment (BOROCIDE): Used for cuts & abrasion.
Acetic acid:
– Weak antiseptic.
– Bactericidal (>5%).
– Occasionally used for burn dressing
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METALLIC SALTS
Mercury compounds: Act by inactivating SH enzymes and acts as bacteriostatic.
Ammoniated mercury
Silver compounds: Astringent action.
Silver nitrate
Zinc salts : Astringent & mild antiseptic
Zinc sulfate

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DYES
Rosaniline dye:
– Gentian violet (0.5-1% alcoholic solution): Effective against staphylococci, gram +ve bacteria & fungi.
– Brilliant green: Rosaniline dye, similar to gentian violet.
– Acriflavine & proflavine: Orangeyellow acridine dye. ACRINOL 0.1% cream. Effective against gram +ve bacteria & gonococci. Activity enhanced in alkaline medium. Used in chronic ulcers & wounds
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Astringent & Obtudents

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Astringents act by precipitating proteins in superficial layers of cells and are used to diminish the excretion or exudation of superficial cells. They are also used as local haemostatics and mummifying agents.
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Types of Astringents Used in Dentistry

1)Tannic acid: It is vegetable astringent obtained from nutgalls. It acts by precipitating protein and gelatin as tannates owing to its acid radical.
Tannic acid glycerine (30% tannic acid) and mouthwashes/ gumpaints containing 1-5% of tannic acid are used to strengthen gums and check bleeding. Its preparations are used as astringent mouth wash, astringent dentrifices, local haemostatics, mummifying agent and obtundent.
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2)ZINC CHLORIDE

It is a caustic astringent, used as 5-10% solution in ulcerative gingivitis, pyorrhoeal pockets and apthous ulcers.
3)ZINC SULPHATE
It is used as astringent in 0.5-1% concentration in the form of mouthwash and lotion in mastoiditis, stomatitis and chronic alveolar abscess.
4)COPPER SULPHATE
It is used as astringent mouth in 0.5- 2% concentration in indolent ulcer of gums.
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OBTUNDENTS

Agents which are used to either diminish or eliminate the dentine sensitivity to make the excavation painless. But due to the availability of local anaesthetics e.g. xylocaine for painless excavation, the use of obtundents is very limited.
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An ideal obtundent should possess the following characteristics:

(i) It should remove dentive sensitivity and penetrate the dentine sufficiently.
(ii) It should not stain the dentine.
(iii) It should be free from any local irritation or pain.
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Obtudents according to their mechanism of action.
I )Act by destroying the nervous tissue
– Absolute alcohol
II )Act by paralysing the sensory nerve endings
– Phenol creosote
– Benzyl alcohol
– Camphor
– Thymol
– Menthol
– Eugenol (clove oil)
III )Act by precipitating proteins
– Silver nitrate
– Zinc chloride
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PHENOL

On local application, it causes irritation followed by numbness. It is used alone and in combination with chloroform and olive oil in a 2:4:10 ratio. It acts rapidly but does not penetrate deeply and due to its protoplasmic poisonous nature it produces its obtundent action.
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CREOSOTE

Its characteristics and action is same as that of phenol, in addition its penetrability is relatively more.
BENZYL ALCOHOL
Due to its local anaesthetic property it is used as obtundent agent. It can be used either alone or in combination of chloroform and ethyl alcohol in a 5:3:2 ratio.
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CAMPHOR, THYMOL, MENTHOL
All three are volatile oils and are used in a mixture in a ratio of 1:2:1 for rapid action.
The mixture acts initially stimulating and then paralysing the sensory nerve endings.
EUGENOL (CLOVE OIL)
Clove oil is used due to the presence of eugenol as its main constituent. It acts by paralysing the sensory never endings. It is non-irritating but stains the dentine yellow.
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SILVER NITRATE

It is an astringent and causes pain on application followed by desensitization.
It acts by precipitating dentine proteins and liberating acid and stains the dentine black.
ZINC CHLORIDE
Its action is similar to that of silver nitrate but it causes sharp pain and does not stain the dentine.
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