Dental phrmacology

Dental Pharmacology
DR. SWAPNIL BORKAR
POST GRADUATE STUDENT
DEPARTMENT OF PERIODONTICS & ORAL IMPLANTOLOGY
S.D.K.S DENTAL COLLEGE
NAGPUR

Introduction To Pharmacology
Pharmacology is the science that deals with the study
of drugs and their interaction with the living systems.
The useful and toxic effects of many plant and animal
product were known to man in ancient time. The earliest
writing on drugs are the Egyptian Medical papyrus (1600 BC) .
The largest of them Ebers Papyrus lists some 800
preparations.
.

 Though medicine developed simultaneously in several countries the
spread of knowledge was limited because of poorly developed
communication across the world.
 India’s earliest pharmacological writing are form the ‘Vedas’. An
ancient Indian physician Charaka and then Sushuruta and Vagbhata,
described many herbal preparations included in Ayurveda (meaning
the science of life). Indians practiced vaccination as early as 550 BC.
 Various other traditional systems of
medicine were practiced in different
parts of the world- like
 Homeopathy ,
 Unani
 Siddh system
 Allopathy

Thus several systems of medicine were introduced of
which only a few survived.
By the end of 17th century the importance of
experimentation, observation and scientific methods of study
became clear.
Francois Magendie and Claude Bernard popularized the
use of animal experiments to understand the effects of drugs.
simultaneous development of the other branches of science
viz. botany, zoology, chemistry and physiology helped in the
better understanding of pharmacology

GENERAL DEFINITIONS
A. Pharmacology is the study of the interaction of chemicals with
living systems.
B. Drugs are chemicals that act on living systems at the chemical
(molecular) level.
C. Medical pharmacology is the study of drugs used for the
diagnosis, prevention, and treatment of disease.
D. Toxicology is the study of the untoward effects of chemical
agents on living systems. It is usually considered an area of
pharmacology.

E. Pharmacodynamic properties of a drug describe the action of
the drug on the body, including receptor interactions, dose-
response phenomena, and mechanisms of therapeutic and toxic
action.
F. Pharmacokinetic properties describe the action of the body on
the drug, including absorption, distribution, metabolism, and
excretion. Elimination of a drug may be achieved by metabolism
or by excretion.
G. Chemotherapy is the use of chemicals for the treatment of
infections. The term now also includes the use of chemical
compounds to treat malignancies.

INTRODUCTION TO PHARMACODYNAMICS
Concentration-Response.
A fundamental principle of pharmacology is that a
relationship exists between the concentration of a drug at its site
of action and its beneficial or toxic action.
The reliance of pharmacodynamic effects upon drug
concentration provides the key link between pharmacokinetics
and pharmacodynamics for it is the action of the body upon a
drug that determines its concentration at its site of action.

Properties of Drug Receptors.
Most receptors are proteins (eg, enzymes, hormone and
neurotransmitter receptors); in addition, some DNA and RNA
molecules serve as drug binding targets.
A successful receptor must distinguish between different
ligands.
That is, it must bind selectively to certain ligands. In many
cases, drugs bind to a site on a protein that normally binds to an
endogenous small molecule or protein.

C. Types of Drug-Receptor Interactions.
When a drug activates a receptor that it binds to, the drug
is an agonist.
Most agonists mimic the effects of small molecules or
proteins that serve as endogenous regulators of the receptor to
which the drug binds.
Pharmacologic antagonists have the opposite effect. That
is, they prevent the effect of endogenous agonists on the
function of the receptor. Most of the time, a pharmacologic
antagonist binds to the same site as an agonist and competes
with the agonist for binding to a critical site on the receptor.
Pharmacologic antagonists have two important properties.
1. In the absence of an agonist, they do not elicit a biologic
response.
2. The effects of a competitive pharmacologic antagonist can be
overcome by adding more agonist.

Graphical Representation of Concentration-Effect Relationships.
The relationship between drug concentration and receptor
binding, and drug concentration and pharmacodynamic effect can
best be understood through the use of graphical representations.

INTRODUCTION TO PHARMACOKINETICS
Pharmacokinetics concerns the effects of the body on the
administered drug. It can be pictured as the processes of
absorption, distribution, and elimination. Elimination includes
both metabolism and excretion. All of these processes involve
movement of drug molecules through various body
compartments and across the barriers separating those
compartments.
:

Absorption of Drugs.
Drugs usually enter the body at sites remote from the
target tissue and are carried by the circulation to the intended site
of action.
Before a drug can enter the bloodstream, it must be
absorbed from its site of administration. The rate and efficiency of
absorption differs depending on the route of administration.

Figure 1.1 Schematic representation of drug absorption, distribution, metabolism, and elimination.

1. Oral (swallowed).
Maximum convenience but may be slower and less
complete than parenteral routes.
Dissolution of solid formulations (eg, tablets) must occur
first. The drug must survive exposure to stomach acid.
This route of administration is subject to the first pass
effect (metabolism of a significant amount of drug in the gut wall
and the liver, before it reaches the systemic circulation).

2. Sublingual (under the tongue)
Permits direct absorption into the systemic venous
circulation thus avoiding the first pass effect.
May be fast or slow depending on the physical
formulation of the product.
Nitroglycerin is administered by this route in the
treatment of angina.
3. Rectal (suppository)
Same advantage as sublingual route
larger amounts are feasible.
Useful for patients who cannot take oral medications
(eg, because of nausea and vomiting).

4. Intramuscular.
Absorption is sometimes faster and more complete than after
oral administration.
Large volumes (eg, 5 - 10 mL) may be given.
Requires an injection.
Generally more painful than subcutaneous injection.
Vaccines are usually administered by this route.
5. Subcutaneous.
Slower absorption than intramuscular.
Large volumes are not feasible.
Requires an injection.
Insulin is administered by this route.

6. Inhalation.
For respiratory diseases, this route deposits drug close to
the target organ; when used for systemic administration (e.g.,
nicotine in cigarettes, inhaled general anesthetics) it provides
rapid absorption because of the large surface area available in the
lungs.

7. Topical.
Application to the skin or mucous membrane of the nose,
throat, airway, or vagina for a local effect.
It is important to note that topical drug administration can
result in significant absorption of drug into the systemic
circulation.
Drugs used to treat asthma are usually administered this
way.

8. Transdermal.
Application to the skin for systemic effect. Transdermal
preparations generally are patches that stick to the skin and are
worn for a number of hours or even days.
To be effective by the transdermal route, drugs need to be
quite lipophilic.
Nicotine is available as a transdermal patch for those who
are trying to stop cigarette smoking.
9. Intravenous.
Instantaneous and complete absorption (by definition, 100%);
potentially more dangerous because the systemic circulation is
transiently exposed to high drug concentrations

Distribution of Drugs.
The distribution of drugs from the site of absorption, through
the bloodstream and to the target tissue depends upon:
1. The blood flow to the tissue is important in the rate of uptake
of a drug.
Tissues that receive a high degree of blood flow (eg, brain,
kidney) have a fast rate of uptake whereas tissues with a low
degree of blood flow (eg, adipose tissue) accumulate drug
more slowly.
2. Solubility of the drug in the tissue.
Some tissues, eg, brain, have a high lipid content and dissolve a
higher concentration of lipophilic agents

3. Binding of the drug to macromolecules in the blood or tissue
limits their distribution.
4. The ability to cross special barriers.
Many drugs are poorly distributed to the brain and the
testis because these tissues contain specialized capillaries (the
smallest type of blood vessel).
The endothelial cells that line these capillaries form a
blood-brain barrier and a blood-testis barrier by preventing the
movement of hydrophilic molecules out of the blood and into the
tissue, and by actively pumping lipophilic molecules out of the
endothelial cell and into the blood.

Of special concern is the ability of drugs to distribute to
breast milk in lactating women, and the ability of drugs to cross
the placenta and affect the developing fetus.
A number of drugs are known to be teratogens (drugs
that cause abnormal fetal development) and should be avoided
in pregnancy.
Women taking drugs that are considered unsafe for
infants and that achieve appreciably high concentrations in
breast milk should not breast-feed their infants

C. Elimination of Drugs.
The rate of elimination (disappearance of active drug molecules
from the bloodstream or body) is almost always related to termination
of pharmacodynamic effect.
There are two major routes of elimination:
1. Excretion.
The most common route for drug excretion is through the kidney
and out of the body in the urine. To be excreted by the kidney, drugs
need to be reasonably hydrophilic so that they will remain in the fluid
that becomes the urine. Patients with impaired kidney function usually
have a reduced ability to eliminate hydrophilic drugs. To avoid
excessively high drug concentrations in these patients, we will need to
reduce their dosages or give dosages less frequently. A few drugs enter
the bile duct and are excreted in the feces.

Metabolism.
The action of many drugs, especially lipophilic compounds,
is terminated by enzymatic conversion, or metabolism, to
biologically inactive derivatives.
In most cases, the enzymatic conversion forms a more
hydrophilic compound that can be more readily excreted in the
urine.
Most of the enzymes that catalyze drug-metabolizing
reactions are located in the gastrointestinal tract and the liver.
Some drugs inhibit drug-metabolizing enzymes and thus
cause drug-drug interactions when co-administered with drugs
that depend upon metabolism for elimination.

Sources of Drugs :
Natural
Plant –
atropine , morphine
quinine , digoxin
Animal –
insulin , heparin , gonadotropin
Minerals-
magnesium sulphate , aluminium hydroxide ,
iron , sulphur
Micro organism –
obtain from sum bacteria or fungi we thus have
penicillin, chephalosporins , tetracycline's
(text book of pharmacology 2ed edition)

Humans :
 Immunoglobulin's from blood
 growth hormones from anterior pituitary
 chorionic gonadotropins from urine of pregnant women.
Synthetic :
 Quniolones
 omeprazole
 neostigmine

Dental Pharmacology INTRODUCTION
Rapid progress in dental pharmacotherapeutics
requires that clinicians constantly update their knowledge of
new drugs, drug interactions and useful therapeutic trends
These drugs play a useful role in the treatment of
ulcerations, inflammations, xerostomia and bleeding during
gingival retraction.
They also help in reducing dentinal hypersensitivity
during vital tooth preparation and increasing the gingival
resistance against infections.

LA are the drugs which upon topical application or local injection
cause reversible loss of sensory perception, especially of pain, in a
restricted area of the body.
These drugs act by excessive stimulation followed by depression
(Bennett, 1984a).
To work efficiently, the dental local anesthetics should have
some requirements (Haas, 2002) such as:
• High intrinsic activity, which ensures complete anesthesia for all dental
treatment
• Rapid onset
• Adequate duration of anesthesia (30 to 60 min for standard dental
treatment)
• Low systemic toxicity
• High efficacy-toxicity ratio
• Low overall incidence of serious adverse effects

Chemically local anesthetics are classified as
Esters
cocaine
procaine
tetracaine
benzocuaine
Amide types
lignocain
mepivacain
bupivacain
etidocaine

Local anesthetics containing vasoconstrictor agents are to be used
with caution in patients with
 Pheochromocytoma
 uncontrolled or unstable angina
 cardiac arrhythmias
 Congestive heart failure
 Hyperthyroidism
 diabetes.
 (Bennett, 1984c)

If allergic reactions occur,
The immediate treatment is
intravenous injection of 0.01 ml per kilogram body weight
adrenaline,
supplemented by antihistamine agents such as 10 to 20 mg
chorpheniramine,
or 50 mg hydroxyzine or promethazine hydrochloride (Ball, 1999).

Topical anesthetics
are used in the oral cavity to provide pain relief at needle
insertion site and over ulcerations.
Topical anesthetic agents can also provide some
form of relief in patients exhibiting gagging during the
impression procedure.
Glycerine, lanolin, petrolatum, mineral oil, sodium
carboxymethylcellulose, propylene glycol and
polyethylene glycol are used as vehicles for topical
Anesthetics (Adriani and Zepernick, 1964).

Vasoconstrictors are used in dentistry either as
components of the local anesthetic syringe or for application with
gingival retraction cords.
These agents do not produce coagulation of blood but act
by constricting blood vessels.
Examples of vasoconstrictors accepted by the Council on Dental
Therapeutics include
Epinephrine (1:200,000/1:100,000/1:50,000),
Levonordefrine (1:20,000)
Norepinephrine (1:30,000).
Epinephrine is the vasoconstrictor of choice for use in dentistry
(Felpel, 1999).

It restricts the blood supply to the area by decreasing the
size of blood capillaries thereby decreasing hemorrhage and fluid
seepage.
It is advisable to use low concentration epinephrine (0.01%)
for gingival retraction due to its superior effect in keeping the
gingival sulcus relatively dry during the impression procedure
(Csillag et al., 2007).

Antiseptics
Antiseptics are drugs that are applied on the body surfaces
to prevent infection by killing or inhibiting the growth of
pathogenic bacteria either by oxidation of bacterial protoplasm or
denaturation of bacterial proteins including enzymes
(Tripathi, 2008a).
Amongst the various types of antiseptics available,
chlorhexidine a biguanide, is one of the most commonly used.

First Generation
Phenols
Quaternary Ammonium compounds
Metallic ions
Sanguinaris
Second Generation
Bis biguanides
Third Generation
Delmopinol
Classification of Chemical Plaque Control agents

a) Phenols (Triclosan):
It’s a phenol derivative which is synthesized used as a topical
antimicrobial agent with a broad spectrum of action including against
both gram -ve and gram +ve bacteria.
It also has specific action against mycobacterium and candida species.
Mechanism of Action:
Triclosan acts on cytoplasmic membrane and induce leakage of cellular
contents which leads to bacteriolysis and Cell death.
Triclosan is induced in toothpaste to prevent plaque formation.
It is used along with zinc citrate or its polymer gantrez to
enhance its retention in the oral cavity.
It also inhibits prostaglandins and leukotriens thereby it reduces
the degree of inflammation.

Metallic ions:
These are Zn -ions and Cu -ions.
It acts by reducing the glycolytic activity in bacteria and hence delays
bacterial growth.
Quaternary Ammonium Compounds:
These are Benzathonium Chloride, Benzallenium Chloride and
Cetylpyredinum. These are cationic antiseptics and surface active agents
which are effective against gram +ve organisms.
Mechanism of action:
Positively charged molecule reacts with negatively charged cell
membrane phosphates and thereby disrupting the bacterial cell wall
structure.
The side effects
 staining and enhanced calculus formation
 it also causes burning sensation and desquamation.

Sanguinare:
 Sanguinare chloride is currently used in both mouth rinses and
toothpaste.
 It is an extract from blood root plant Sanguinare candensis.
 It is an benzophenanthredine alleloid.
 Mechanism of action is not known.
 It is most effective against gram positive organisms.

Second generation
Bisbiguanides:
isbiguanides posses anti plaque activity including Chlorhexidine,
Alexidine and Octenidine.
The antiplaque properties of chlorhexidine are unsurpassed by
other agents.
It has much greater and more prolonged effects than other
antiseptics.( Joyston-Bechal 1993)
The digluconate of chlorhexidine (1: 6 – Di 4 – chlorphenyl –
diguanidohexane) is a synthetic antimicrobial drug which is effective in
vitro against both gram positive and gram negative bacteria including
aerobes, anaerobes, yeast and fungi.
( Eley B. 1999)

Mechanism of action:
Prevents pellicle formation by blocking acidic groups of salivary
glycoprotein’s thereby reducing glycoprotein adsorption on to
tooth surface. Prevents adsorption of bacterial cell wall on tooth
surface. Prevents binding of mature plaque
Antibacterial action of Chlorhexidineconsits of two actions, i.e.,
bacteriostatic at low concentration and bactericidal at high
concentration.
Bacteriostatic action at low concentration is mainly due to the
negative energy of the bacterial cell wall reacts with positive energy
chlorhexidine molecule. This alter the integrity of cell membrane
and Chlorhexidine binds to inner membrane phospholipids and
increases permeability. This leads to the vital elements leaks out
resulting in bacterial cell death.

Bactericidal Action is due to the higher concentration of chlorhexidine.
This cause progressive greater damage of membrane and the larger
molecular weight compounds loss and coagulation and precipitation of
cytoplasm.
The Free CHX molecules enter the cell and coagulate proteins and vital
cell activity ceases and cause resultant cell death.
It has shown that 0.2% CHX mouth rinses will prevent development of
experimental gingivitis, it has been shown that Chlorhexidine is more
effective in preventing plaque accumulation on a clean tooth surface
than in reducing pre existing plaque deposits.( Joyston‐Bechal S,1993)
The adverse effects
brown staining of tooth and restoration
loss of taste sensation
stenosis of parotid duct.

It affects the mucous membrane and tongue; and may be related
to the precipitation of chromogenic dietary factors on teeth and
mucus membrane. It is probable that one cationic group attaches
chlorhexidine to the tooth and mucosal surface, which the other
cationic group lyse the bacterial cell wall. Thus the cationic group
can also attach dietary factors such as gallic acid derivatives found
in some foods and beverages including tea, coffee and wines.

Essential oils (Listerine):
It’s a combination of phenol related essential oil, thymol and
methyl salicylate.
It has shown to have moderate plaque inhibitory effect and
antigingivitis effect.
It has poor oral retention and has burning and bitter taste.
(Mandel 1988)
Mechanism of Action:
The action of phenol acid is cell wall disruption and
inhibition of bacterial enzyme.( McDonnell G 1999)
The phenolic compound are also known to act as
scavengers of oxygen free radical and hence has an effect on
leucocyte activity

Third generation
Delmopinol : It’s a relatively new preparation which inhibits plaque
growth and gingivitis.
It interferes with plaque matrix formation and also reduces
bacterial adhesion and adherence.
It ceases binding of plaque to tooth, thus aiding the easy removal
of plaque by mechanical procedures.
It is indicated as a pre brushing mouth rinse.
Adverse effects
 staining of tooth and tongue
 taste disturbances
 mucosal soreness
 erosion

Steroids
Steroids play a role in the modulation of the inflammatory reaction
by inhibitory activity affecting the production of mRNA and thus
protein synthesis. Application of topical steroid preparations
provides temporary relief of symptoms associated with
inflammation and ulcerated lesions in the oral cavity
such as recurrent apthous stomatitis.
These topical ointments include
Triamcinolone acetonide 0.1%
Kenalog in Orabase
Hydrocortisone acetate 1%
Betamethasone dipropionate 0.05%.

Topical use of steroids is usually well tolerated but some patients may
develop a secondary erythematous candidosis or pseudomembranous
candidosis (thrush) if predisposing conditions like
xerostomia,
Systemic and/or topical use of antibiotics
corticosteroid asthma inhalants
prostheses and cigarette smoking are present in them.
Even though clinical experience and laboratory studies have
shown systemic absorption of steroids to be insignificant through the
oral mucosa but caution should be exercised when used in patients with
 Diabetes
 Hypertension
 tuberculosis
(Savage and McCullough, 2005).

Analgesic agents are used for the management of pain
divided :
Nonopioid (non-narcotic)
Acetaminophen (Paracetamol)
Opioid (narcotic).
An important difference between the opioids and the
nonopioid analgesic agents is their mechanism of action.
The action of the nonopioid analgesic agents is related to
their ability to inhibit prostaglandin synthesis at the peripheral
nerve endings whereas the opioids affect the amount of pain by
depressing the central nervous system.

Text book of pharmacology 2ed edition

Opioid Analgesics
Opioid analgesics used in dentistry for
oral administration are Codeine,
Hydrocodone, Oxycodone and
Pentazocaine whereas Morphine,
Meperidine and Fentanyl are used
parenterally .
Opioids are added to
nonopioids to manage pain that is
moderate to severe or that does not
respond to nonopioids alone. Opioids
differ from the nonopioids in that
they have no ceiling effect. The only
dosing limitation is based on side
effects (Felpel, 1997).

Non steroidal anti-inflammatory
Drugs (NSAIDs’)

The NSAIDs constitute a heterogeneous group of drugs
with clinically important analgesic, antipyretic and anti-
inflammatory properties that rank intermediately between
corticoids with
anti-inflammatory properties on one hand, and major analgesics –
opioids on the other (Poveda-Roda et al., 2007).
These agents differ from opioid analgesics in the following ways:
(1) there is a ceiling effect to the analgesia
(2) they do not product tolerance or physical
Dependence
(3) they are antipyretic
(4) they possess both anti-inflammatory as well as analgesic
properties (Yagiela et al., 2004a).

Nonopioids are most effective in treating postprocedural
pain when given before the procedure (or immediately following a
short procedure), thus preventing the synthesis of prostaglandins
that quickly follow the surgical insult.

Physical, chemical or mechanical stimuli in the form of
tissue damage, hypoxia, immune processes, etc. induce
arachidonic acid release and metabolization.
NSAIDs inhibit cyclooxygenase (COX) – the enzyme
responsible for the transformation of arachidonic acid into
prostaglandins and thromboxanes, which are substances
generically referred to as eicosanoids.
These resulting metabolites (prostaglandins and
thromboxanes) exert potent vasodilating action, resulting in
increased vascular permeability, with the extravasation of fluids
and white blood cells therby contributing to inflammation.
Consequently, the inhibition of cyclooxygenase synthesis
exerts a clear anti-inflammatory effect (Poveda-Roda et al., 2007).

Out of the two forms (isoenzymes) of cyclooxygenase
namely COX-1 and COX-2 the latter COX-2 appears to be more
involved with synthesis of prostaglandins at sites of inflammation,
whereas COX-1 is more involved at sites where adverse effects of
NSAIDs are expressed, such as the GIT.
Therefore NSAIDs that have more selective inhibitory
activity on COX-2 as opposed to COX- 1 would be expected to have
a more favorable therapeutic index (Waldman et al., 1982).
Celecoxib, Rofecoxib and Parecoxib are drugs showing selective
COX-2 inhibitory action but these should be avoided in patients
with moderate to severe hepatic damage.

Potential adverse effects of NSAIDs include
 peptic ulcer disease
 gastrointestinal (GI) bleeding,
 GI perforation
 impaired renal function
 inhibition of platelet function.
Salicylates should be avoided in patients suffering from
Ulcers, Asthma, Diabetes, Gout, Influenza and hypercoagulation
states.

Asprin and related salicylates are contraindicated for
treatment in children and teenagers with viral infections, as it has
been associated with hepatotoxicity and encephalopathy (Reye’s
syndrome) (Waldman et al., 1982).
Ibuprofen, naproxen sodium, ketoprofen and asprin are
currently approved by the food and drug administration for over
the counter (OTC) use.
These OTC drugs should not be used consecutively for over
10 days for pain and 3 days for fever (Yagiela et al., 2004b).
A 200 to 800 mg dose of ibuprofen should be considered as
the first choice for management of acute inflammatory pain
(Hargreaves and Abbott, 2005).

Acetaminophen (Paracetamol)
It has analgesic and anti-pyretic effects, and it is a weak
inhibitor of the cyclo-oxygenase sub-groups COX-1 and COX-2.
At therapeutic doses it does not inhibit prostaglandin in the
peripheral tissues so there is very little, if any, anti-inflammatory
action.
It is therefore not classified as an NSAID (Felpel, 1997).
Tolerance and dependence have not been reported, and
Paracetamol does not cause the same gastric irritation or the
other complications associated with aspirin and other NSAIDs
(Seymour et al., 1999).
The usual recommended adult dose of Paracetamol is 500-
1000mg every four to six hours (up to a maximum of 4000mg per
day) (Therapeutic guidelines, 2002).

Combination drug therapy
The goal of combining analgesics with different mechanisms of
action is to use lower doses of the component drugs, thereby improving
analgesia without increasing adverse effects
(Mehlisch, 2002).
Patients with acute dental pain are best treated with NSAIDs or
acetaminophen as the primary analgesic and the addition of a narcotic
should be reserved for situations when additional analgesia is required.
Opioid and acetaminophen combination studies show that a
combination is better than opioids or acetaminophen alone (Moore et al.,
1997).
Opioids such as codeine, hydrocodone and oxycodone combined
with ibuprofen are superior to manage acute dental pain than ibuprofen
alone (Po and Zhang, 1998).

The analgesic properties of aspirin, acetaminophen and ibuprofen
have been seen to increase when combined with 65 to 100 mg
caffeine.

Antibiotics are chemicals virtually always derived naturally
with the exception of ulfonamides, fluoroquinolones and
oxazolidinones.
These drugs act on the microorganisms to effect their
viability hence they can be either bactericidal (inducing cell death)
or bacteriostatic(preventing cell growth or replication) (Yagiela et al.,
2004d).
Antibiotics with activity against a wide range of disease-
causing bacteria are termed as broad-spectrum antibiotics.
It also means that it acts against both Gram-positive and Gram-
negative bacteria.
This is in contrast to a narrow-spectrum antibiotic which is
effective against only specific families of bacteria.

tetracyclines and clindamycin are accepted by the Council
on Dental therapeutics, ADA.
Other antibiotics appropriate for use in Dentistry include
penicillin,
erythromycin
cephalosporins
bacitracin (Felpel, 1997).
Oral infections are usually caused by aerobic gram-positive cocci
(Staphylococcus aureus) and anaerobic microorganisms
(Peptostreptococcus) and the use of antibiotics in dentistry is to
either treat these or as a prophylaxis to prevent bacterial
endocarditis that is caused by α hemolytic streptococci

Most acute oral infections respond well to one of the oral
penicillin preparations.
adverse side effects, and allergic reactions.
A true allergic reaction usually manifests as an irritating rash.
Anaphylactoid reactions though rare, occur in
susceptible patients within 30 seconds of an im inj.
Signs and symptoms of anaphylaxis include
 oral paresthesia
 cold hands feet
 Bronchospasm
 wheezing,
 circulatory collapse
 unconsciousness

Alternatives to penicillin include
 Erythromycin
 Cephalosporins
 Clindamycin,
 Tetracycline
but Cephalosporins should not be used in a person with a history
of
anaphylaxis, angioedema or urticaria with penicillins or ampicillin.
Erythromycin estolate
Erythromycin ethylsuccinate
Contraindicated
liver dysfunction as they can cause cholestatic hepatitis.

Tetracyclines –
avoided during
Pregnancy
children below 8 years because permanent staining of deciduous
and permanent teeth and retardation of bone growth may occur.
gastrointestinal upset
Hepatotoxicity
Nephrotoxicity
photosensitivity
impaired calcium
absorption.
Similarly, quinolones should be avoided in children, pregnant or
nursing women, and in epileptics (Felpel, 1997).

Antibiotic prophylaxis is recommended for dental procedure
in patients with prosthetic cardiac valve, previous infective endocarditis,
cardiac transplantation recipients who develop cardiac valvulopathy and
during the first six months following any procedure to treat congenital
heart disease (Prevention of infectiveendocarditis, 2007).
Antibiotic coverage for invasive dental procedures is
recommended in patients with poorly controlled or uncontrolled
diabetes, infective endocarditis but not in those having orthopedic
prosthesis placed over 2 years prior to the dental procedure.
Prophylactic use of antibiotics in conjunction with dental
treatment should be avoided unless there is a clear indication since
unwarranted overuse of antibiotics can lead to development of resistant
strains of microorganisms (Barker, 1999).

Antibiotic prophylactic regimen for dental procedures in
high risk patients

Oral moniliasis (thrush) is a fungal infection of the oral cavity caused by
Candida albicans.
C albicans can also colonize prosthetic devices like dentures.
Atleast 2 weeks of therapy are required for treating oral candidiasis.
Nystatin (Mycostatin) is the most common drug used in dentistry and it
can have a fungistatic or fungicidal effect depending on its dose.
A 2-3 ml (100,000 units/ ml) suspension or
1-2 lozenges (200,000 units each)
may be used four to five times per day.
Colonized dentures can be treated by soaking them in a nystatin solution
or applying an ointment (100,000/g) of nystatin to the tissue surface.

Clotrimazole (Mycelex), a fungistatic can be used in a dose of 10
mg troches dissolved in the mouth five times a day
Since Nystatin and Clotrimazole are not appreciably absorbed
from the gastrointestinal tract, the topical route is preferred for
their administration.
Oral Fluconazole (Diflucan) in a dose of 50 to 100 mg/day and
Itraconazole (Sporanox) 200mg/day are broad-spectrum
antifungal agents that are effective in treating oropharyngeal and
esophageal candidiasis (Yagiela et al., 2004e).

Antianxiety agents are used in clinical dentistry for premedication in an
apprehensive patients pending operative procedure like Implant surgery.
Antianxiety agents are known to summate with
Anesthetics
opioid analgesics
Antidepressants
sedative-hypnotics
alcohol to cause excessive CNS depression (Yagiela et al, 2004f)
hence should be prescribed with caution.
Benzodiazepines such as
Diazepam (Valium),
Lorazepam (Ativan)
and Alprazolam (Xanax)
Antihistamines such as
Hydroxyzine (Vistaril)
Promethazine (Phenergan)
are the preferred anxiolytics for use in dentistry.

They should preferably have a rapid onset and a short duration of
action.
Diazepam (2-10mg),
Lorazepam (2-6 mg)
Alprazolam (0.25-1.5mg) have a 12-24 hour duration of action
whereas antihistamines in a dose of 25-100mg have a 4-6 hour
duration of action.
The use of Benzodiazepines is contraindicated in patients with
psychosis,
acute narrow-angle glaucoma
liver disease.

Centrally Acting Muscle Relaxants

These are drugs that reduce skeletal muscle tone without altering
consciousness.
They are used in chronic spastic conditions and acute muscle
spasms of the temporomandibular joint.
These drugs usually cause slight sedation hence caution is to be
exercised regarding operation of motor vehicles.
These drugs have a potential for abuse and dependence hence
prolonged administration and abrupt stoppage is to be avoided
(Stanko, 1990).

Definition
According To ADA council on dental “a dentifrice is a substance
use with a toothbrush for the purpose of cleaning the accessible
surfaces of the teeth”.
Webster described the term dentifrice as derived from (Latin)
dens (tooth)
fricare (to rub)
Came into English in 1558.
Dorland described it as a preparation for cleaning and polishing
the teeth.

Functions of a toothpaste (in conjunction with toothbrush):
 Minimizing build up of plaque.
 Strengthening teeth against caries.
 Cleaning teeth by removing stains.
 Removing tooth debris.
 Freshening the mouth.
 Composition:
Dentifrices have been prepared in several physical forms
- Pastes
- Powder
- Liquid
- gel

Powder dentifrices :
abrasive,
detergents,
Flavoring
sweetening agents.
Paste dentifrices: contain the above plus
binders,
preservative ,
humectant,
water

The polishing or abrasive agent(25-50 %):
 An ideal abrasive is one that cleans well with no damage to the
tooth surface and provides a high polish that can prevent or
delay the reaccumalation of stains and deposits.
 Abrasives by volume are the single largest components of a
dentifrice.
Abrasive agent has two purposes:
 Firstly, its mild abrasive action helps to eliminate plaque from
the teeth, hence reducing plaque build up.
 Secondly, the abrasive agent removes stained pellicle from the
teeth, polishes the surfaces, restores the natural luster and
enhances enamel whiteness

 Abrasive agent must be chosen very carefully, so that there is
no scratching or damaging the enamel or the much softer
underlying dentine.
 In particular attention is paid to the size of the particles and
their shape and hardness.
 The abrasive system should be insoluble, inert nontoxic and
preferably white.
 Commonly used abrasive materials include calcium carbonate,
dicalciurn phosphate dihydrate, alumina and silicas.
 In gel toothpaste, the abrasive system is usually a special
porous silica that becomes transparent when blended into the
gel system.

The binder or thickener(1-2%):
 The binder or thickener controls the stability and consistency of
a toothpaste, and also affects the ease of dispersion of the
paste in the mouth.
 Choice of the correct binder and concentration is critical to
ensure that the product can be readily squeezed from the tube
and yet have a good appearance when it is on the toothbrush.
Commonly used thickeners can be divided into two classes –
 Water soluble- carrageenates, alginates and sodium
carboxymethylcellulose.
 Water insoluble - magnesium aluminum silicate, sodium
magnesium silicate and colloidal silica.

The surfactant agent /detergent (1-3%):
Purposes:
1. To Lower surface tension.
2. Penetrate and loosen surface deposits and stains.
3. Emulsify debris for easy removal by toothbrush.
 The surfactant agent provides the foam that causes the
removal of food debris and aids dispersion of the product in
the mouth.
 Early dentifrices actually used soap, but mild synthetic
detergents are now universally used to give better taste, foam
and product stability.

 The detergent used most widely by all major manufacturers is
sodium lauryl sulfate.
 Sodium lauryl sulfate also has anti microbial properties and thus
helps to preserve the toothpaste during manufacture and use.
 It also has a rapid antimicrobial effect on oral flora, which adds
to the overall plaque-inhibiting properties of the toothpaste.
 Another positive role sodium lauryl sulfate has is to help to
solubilize key ingredients such as flavors and certain anti-
microbial agents.

Surfactant used should fulfill the following criteria:
 Non toxic
 Neutral in reaction
 Active in acid or alkaline media.
 Stable
 Compatible with other dentifrice ingredients.
 No distinctive flavor
 Have foaming characteristics.
Examples :
1. Synthetic detergents
2. Sodium lauryl sulfate
3. Sodium and lauryl sarcosinate

The humectant :
 A humectant is a material that helps to reduce the loss of
moisture from a preparation.
 In toothpaste, the humectant minimizes plug formation in tube
nozzles and improves the texture and feel of the product in the
mouth.
 It can also act as a sweetening agent.
 Examples are: glycerin, sorbitol and polyethylene glycol.
Glycerin and sorbitol are the humectants used most often .

The flavoring agents
 The choice of flavor is very important.
 It renders the product pleasant to use and should leave a fresh
taste in the mouth after use.
 Types of flavor : peppermint oil, spearmint oil and wintergreen
(methyl salicylate).
 Others - wintergreen, aniseed, lemon oil and eucalyptus are also
usually added to improve the acceptability of the flavor and to
add individual notes to the flavors - important in medicinal
formulations
Uses of flavor:
1. To make dentifrice desirable
2. To make other ingredients that may have a less pleasant
flavor

Water (20-30%):
 Most important of the remaining ingredients.
 Serves as vehicle to deliver ingredients of toothpaste.
 Deionized or distilled water is utilized

Preservatives (0.05-0.5%):
Most dentifrice humectants and some organic binders are
susceptible to attack by microorganisms or molds.
Hence preservatives such as dichlorophene benzoate, p-
hydroxy benzoate, formaldehyde or paraben
Others:
Titanium dioxide to whiten the preparation

Therapeutic agents (0.4 – 1.0 %)
Toothpaste is an excellent vehicle for delivering oral health
benefits and hence many therapeutic agents are added.
These include
Anti caries agents
Anti plaque agents
Anti tartar agents
Anti sensitivity agents.
Therapeutic agents and their mechanism of action:

ANTI-CARIES AGENTS
1. Fluoride:
Fluoride is considered to be the most effective caries-inhibiting
agent, and almost all toothpastes today contain fluoride in one form
or the other.
Most common form
- sodium fluoride(NaF).
Mono-fluoro-phosphate (MFP)
Stannous fluoride (SnF) are also used.
The fluoride amount in toothpaste is usually between 0.10-0.15 %.
Toothpastes are the main vehicle for fluoride.

Three main theories considering the positive action of fluoride in
the prevention Of caries:
1. It is claimed that fluoride, incorporated into the enamel
during tooth development in the form of fluorhydroxyapatite
(FAP), reduces the solubility of the apatite .
2. It is also suggested that fluoride has antibacterial actions.
In an acidic environment, if fluoride is present, hydrogen
fluoride (HF) is formed .
3. Today the most important anti-caries effect is claimed to
be due to the formation of calcium fluoride (CaF2) in plaque
and on the enamel surface during and after rinsing or
brushing with fluoride. CaF2 serves as a fluoride reservoir .

2. XYLITOL
Xylitol is a sugar alcohol that cannot be fermented by oral
microorganisms.
It is considered to be a cariostatic agent since it can inhibit
the carbohydrate metabolism in different oral microorganisms .
The inhibitory effect on glycolysis has been related to the
uptake of xylitol via a constitutive fructose specific PTS system
and subsequent intracellular accumulation of xylitol-5-phosphate.
Such a mechanism leads to reduced acid formation from glucose,
and a reduction in the streptococcus mutans content in both
plaque and saliva

3. Calcium/Phosphate:
Calcium and phosphate supplementation in a toothpaste
will increase the concentration of these ions in the oral cavity.
This has been reported to improve remineralization and
increase fluoride uptake.
4.Sodium Bicarbonate:
Several studies have shown that bicarbonate is one of the
salivary components that potentially modifies the formation of
caries.
It increases the pH in saliva, and in this way creates a
hostile environment for the growth of aciduric bacteria.
Sodium bicarbonate can also change the virulence of the
bacteria that cause tooth decay

ANTI-CALCULUS AGENTS
 Of the anti-calculus agents, the crystal growth inhibitors
have been most extensively tested clinically. These agents act
by delaying dental plaque calcification, thereby promoting
plaque removal with normal tooth brushing
1.Pyrophosphate:
 Inhibit the formation of supragingival dental calculus.
 Added as tetrasodium pyrophosphate, tetrapotassium
pyrophosphate or disodium pyrophosphate.
 It has been shown that pyrophosphate has high affinity to
hydroxyapatite (HA) surfaces, probably by an interaction with
Ca+ in the hydration layer, reduces their protein-binding
capacity.

It also has the ability to inhibit calcium phosphate
formation. It is therefore conceivable that pyrophosphate
introduced in the oral cavity through dentifrices may affect
pellicle formation.
P-O-P bond of pyrophosphate is susceptible to enzymatic
hydrolysis by plaque and salivary phosphatases, and the effect may
thus be of limited duration in the oral cavity .
Tartar control dentifrices that contain pyrophosphate
incorporate phosphates inhibitors that prolong the activity of
pyrophosphate in the mouth.

. Zinc:
 Zinc has anti-calculus effect due to its anti-plaque properties,
but in addition it is thought to influence calculus formation by
inhibiting crystal growth

ANTI-DENTINE HYPERSENSITIVITY AGENTS
Although the condition is referred to as "dentine
hypersensitivity" it isn't really the dentine that is sensitive. The
sensitivity of dentine is caused by fluid-filled tubules in
communication with the pulp.
Potassium salts:
Potassium ions are thought to act by blocking action
potential generation in intradental nerves.
It is claimed that potassium salts increase the
concentration of potassium ions around the pulpal nerves, and
thereby depolarizes the nerve. This can inhibit a nerve response
from different stimuli .
The exact mechanism by how potassium desensitises
dentine is yet to be elucidated.

ANTI-APHTOUS AGENTS
Aminoglucosidase and Glucose oxidase:
Enzymatic toothpastes do not contain detergents like SLS
because the detergent can denaturate the enzymes.
SLS may induce adverse effects in oral soft tissues and
increases the frequency of ulcers in patients suffering from
recurrent aphthous ulcers (RAU). Enzyme toothpastes can
therefore be an alternative for patients suffering from RAU .
Use of a dentifrice containing the combination of the
enzymes aminoglucosidase and glucose oxidase has a positive,
inhibiting effect on RAU.
The ulcers were generally reported to be smaller and less
painful, to have a shorter healing time and the frequencies of
aphthous ulcers episodes were decreased.

WHITENING AGENTS
 Whitening toothpastes do not lighten the colour of the
tooth structure; they simply remove surface stains with
abrasives or special chemical or polishing agents, or prevent
stain formation.
1. Abrasives:
 An abrasive is required for the effective removal of a
discoloured pellicle.
 Abrasives provide a significant whitening benefit, particularly
on smooth surfaces.
 limited use for areas along the gum line and interproximally .
 Coarse abrasives in toothpates can damage the dental tissue.

2.Dimethicones:
Dimethicones are versatile substances that ranges from
low molecular weight polydimethylsiloxane fluids to high
molecular weight polymers that are gum-like in nature. They
cause a smooth surface on the tooth that prevents stain
formation.
3. Papain:
Papain is a sulfahydryl protease consisting of a single
polypeptide chain, extracted from the Carica papaya plant. It is
able to hydrolyse peptide bonds, and can also catalyse the
transfer of an acyl group. It is used in toothpastes as an non-
abrasive whitening agent
4. Sodium bicarbonate:
Dentifrices containing high concentrations of sodium
bicarbonate are more effective in removing intrinsic tooth stain
than those not containing sodium bicarbonate

ANTI-HALITOSIS AGENTS
Zinc:
Halitosis originates mainly from the oral cavity and is due
to the retention of anaerobic, Gram-negative bacteria.
These bacteria use sulphur containing amino acids as
substrates in their production of volatile sulphur-containing
compounds (VSC).
VSC have a distinctly unpleasant odour even in low
concentrations Zinc inhibits the production of VSC in the oral
cavity by interacting with sulphur in the amino acids or their
metabolism.
Zinc can be retained in the oral cavity for approximately 2-3
hours after tooth brushing by binding to acidic substances on the
oral mucosa, in the saliva or on bacterial surfaces.

Astringents
Astringents are the substances that precipitate proteins, but do
not penetrate cells, thus affecting the superficial layer of mucosa only.
They toughen the surface by making it mechanically stronger and
decrease exudation.
Astringents may be administered by retraction cords already
impregnated with the agent or by applying them to cotton pellets.
Examples
 Alum
 aluminum chloride
 zinc chloride (8-20%)
 tannic acid

Styptics are the concentrated form of astringents.
They cause superficial and local coagulation.
Some of the examples are ferric chloride and ferric sulfate.
Aluminum chloride and Ferrous sulfate are preferred astringents
amongst prosthodontists because they cause minimum tissue
damage (Rosenstiel, 2006a).

Hemostatic Agents
Hemostatic agents are used in dentistry for hemorrhage control and
wound protection (Mc Bee and Koerner, 2005).
These are drugs which arrest more serious bleeding from cut or
lacerated capillaries and arterioles.
Some of the examples are:
I. Thrombin- It is prepared from mammalian pro-thrombin, acts by
accelerating the clotting of blood.
It is available in powder form and mixed with saline.
It should be applied locally and never injected.
II. Gel Foam- It is also known as gelatin sponge and is available as a
powder or porous sheet.
The hemostatic properties of absorbable gelatin sponge can be
improved by soaking it in a thrombin solution before application
(Felpel, 1999).

Xerostomia may result from disease states (Sjogren's
syndrome, rheumatoid arthritis, diabetes insipidus, pernicious
anemia), from radiation, as a side effect of a wide variety of
drugs, or from natural aging.
Sialogogues are the agents which activate muscarinic
cholinergic receptors of the parasympathetic nervous system to
increase salivary flow in patients with xerostomia (Tripathi,
2008b).
All commercially available preparations have a limited
duration of action, making frequent application necessary.
Agents such as sugar free gum or candies and lozenges
containing citric acid sorbitol, mannitol or xylitol may be
recommended.

According to Boucher, making a conscious effort of consuming at
least eight glasses of water, juice or milk daily is the most
important measure to relieve dry mouth
(Zarb and Bolender, 2004a).
Pilocarpine have been reported as potentially effective
sialogogues for xerostomic patients in a study on patients with dry
mouth following cancer therapy
(Gorsky et al., 2004).
Carboxy methyl cellulose based artificial saliva demonstrated
moderate effects in reducing dry mouth related symptoms with
more significant effects appearing in patients whose residual
secretory potency was severely compromised
(Oh et al., 2008).

These agents are used to decrease salivary secretion by
cholinergic antagonist action.
They decrease salivary secretion by inhibiting the action of myo-
epithelial cells in the salivary glands thus producing a dry field.
examples of anti-sialogouges,
Methantheline
Propantheline (synthetic atropine derivatives)
with Propantheline being 5 times more potent.
Clonidine (0.2mg) an antihypertensive drug has been found to be
as effective as methantheline (50 mg) in reducing salivary flow (Wilson
et al., 1984).
For the desired reduction in salivary flow, the oral administration of
atropine, scopolamine, or methantheline and propantheline should
precede the clinical procedure by 1to 2 h, half to 1 h, or one-half
an hour, respectively.

Medications with anti sialogogic effect include
(Rosenstiel et al., 2006b);
 probanthine (7.5 to 15 mg),
 robinul (1 to 2 mg),
 saltropine (0.4 mg) and
 antipasbentyl (10 to 20 mg).
Anticholinergic drugs are contraindicated in patients with
glaucoma, prostatic hypertrophy, severe gastrointestinal disorders
(ulcerative colitis, obstructive disease, intestinal atony), and
myasthenia gravis (Felpel, 1999).

Gum Paints
Gum paints are the combination of antiseptics and tanning
agents which precipitate proteins but do not penetrate cells thereby
affecting only the superficial layer making it mechanically stronger and
decreases exudation.
They have germicidal, fungicidal, anesthetic and healing
properties.
When applied, they provide a soothing, cooling and an astringent effect.
All these preparations contain
 Choline salicylate
 Tannic acid
 Cetrimide,
 Thymol
 Camphor,
 Cinnamon oil
 Iodine
 Alum (hydrated potassium aluminumsulfate).

‘Zingisol’ containing 2% Zinc Sulfate is used to control bleeding
gums.
The patient is advised to apply 3-4 drops on finger and massage
3-4 times a day.
‘Sensoform’ gum paint (Warren) contains tannic acid, glycerine
and potassium iodide and is applied on affected area several times with
the cotton applicator for the treatment of stomatitis, inflammation and
bleeding gums.
It also decreases sensitivity and increases gingival resistance
against infections.
‘Stolin’ gum paint (dr. reddy’s)15ml contains
cetrimide 0.1 % w/v
tannic acid 2 % w/v
zinc chloride 1 % w/v.
‘Sensorok’ gum astringent with zinc sulfate is used for gum
massage 2-3 times daily

It must be emphasized that improper care of dentures can
have detrimental effects on the health of the denture supporting
tissues. Maintenance of adequate denture hygiene is essential to
minimize and eliminate adverse tissue reactions.
It must be an integral component of post insertion patient
care (Zarb and Bolender, 2004b).
Following are the requirements of an ideal denture cleanser:
- Should be non toxic
- Easy to remove and harmless to the patient
- Be able to dissolve the denture deposits such as calculus
- Exhibit bacteriocidal and fungicidal effect
- Should have long shelf life and inexpensive
- Harmless to the denture base materials, denture teeth as well as
soft liners

Commonly available denture cleansers are available in powder
and tablet form and include:
a) Oxygenating cleansers- overnight immersion of dentures in alkaline
peroxide solution is a safe and effective method.
b) Hypochlorite cleansers- immersion of the dentures in a solution of one
part of 5% sodium hypochlorite in three parts of water followed by light
brushing is advisable.
c) Dilute mineral acids.
d) Abrasive powders and pastes.
e) Enzyme containing minerals (proteases).
Commercially available denture cleansers include
Kleenex, Stain Away, Polident, Triclean, Efferdent

Denture adhesives augment the same retentive mechanisms already
operating when a denture is worn.
They consist of keraya gum,
tragacanth,
sodium carboxyl methyl cellulose,
polyethylene oxide,
flavouring agents,
antimicrobial agents
plasticizers
They enhance retention through optimizing interfacial forces by
increasing the adhesive and cohesive properties and viscosity of the
medium lying between the denture and the basal seat and eliminating
voids between the denture base and the basal seat
(Zarb and Bolender, 2004c).

Oral Protective Agents
These agents are finely powdered, inert and insoluble.
They afford physical protection to the mucous membrane thus are used
for apthous ulcers and gingival inflammation.
All these gel preparations should be applied 2-3 times daily.
The Lignocaine based preparations contain
Lignocaine hydrochloride, Benzalkonium and Choline salicylate.
Examples are Dentogel, Dologel and Emergel.
Dentasep, Dentonex-M, Maghex-M and Metrogyl DG gel are
examples of metronidazole and chlorhexidine preparations.
Oraguard B and Mucopain are gels containing Benzocaine as the active
ingredient. Petroleum jelly is also used successfully as an oral protective
agent

Demulcents
These are inert substances which sooth the inflamed and denuded
mucosa by preventing contact with air or irritants in the
surrounding.
They can be applied as thick colloidal and viscid solutions in water.
Commonly used agents are
Gum Acacia
Gum Tragacanth.
These are used as suspending agents for indiffusible powders,
emulsifying agents for oils and in lozenges.
Glycerin (50-75%) in water acts as a popular vehicle for gum paint
(Tripathi, 2008c).

CONCLUSION
All the pharmacological agents mentioned are used either
before commencement of the treatment, during the treatment or
at the post treatment duration.
Therefore, a dentist should have sound knowledge of the
benefits and drawbacks of these agents in achieving the desired
results

Dental phrmacology

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