Dental products – Pharmaceutical Inorganic Chemistry B. Pharma 1st Semester

Dental products

Introduction:

Dental products are used to maintain the dental and oral
hygienic condition in a human being.

There are numerous inorganic compounds used in the
preparation of dental products like fluoride salts, calcium salts etc. They are
mainly used to prevent the dental problems like dental caries, gingivitis and
bad breath. Dental products included anitcaries, cleaning agents, desensitizing
agents, polishing agent, oral antiseptic and astringents.

What are the problems related to
tooth?

      Bad breath

     Tooth decay

     Gum problems

     Oral cancer

     Mouth sores

     Tooth erosion

     Tooth
sensitivity

     Tooth aches

     Unattractive
smile

A large numbers of inorganic chemicals and their
preparations are known which find their application in the practice of dental
care and oral disorders. As they come in contact with the human body, they are
regarded like other drugs and pharmaceuticals.

Dental products
include:

1. Anti caries agent: Sodium Fluoride

2. Desensitizing agents: Zinc chloride

3. Dentifrices: Calcium carbonate

Dental CARIES

Dental caries or tooth decay is a disease of the teeth
caused by the action of acid mostly lactic acid obtained by the action of
certain microorganism on fermentable carbohydrates. Acid produced by bacterial
metabolism of fermenting carbohydrates act on the teeth, produce lesions or a
cavity where bacteria get localized and dental caries takes place. This disease
is characterized by decalcification of tooth along with the bad smell of the
mouth.

Two specific groups of bacteria found in the mouth that are
responsible for dental caries:

a. Mutans streptococci (Streptococcus mutans)

b. Lactobacilli

Mechanism of
formation of dental caries

For caries to develop, three factors must occur at the same
time:

     A susceptible
tooth

     Diet rich in
fermentable carbohydrates

     Specific
bacteria (regardless of other factors, caries cannot occur without bacteria)

METHODS TO CONTROL CARIES

1. Chemical measures

2. Nutritional measures

3. Mechanical measures

Chemical measures
include:

I. Substances
which alter tooth surface or tooth structure: Chemicals falling into this
categories Include:

     Fluorides

     Iodides

     Bisbiguanides

     Silver nitrates

     Zinc chloride
and potassium ferrocyanates

II. Substances
which interfere with carbohydrate degradation through enzymatic alteration

• Includes:-

1. Vitamin K

2. Sarcoside

     Vitamin K

– Vit. K was found to prevent acid formation in incubated
mixtures of glucose and saliva

     Sarcoside

– Sodium-N-lauryl sarcosinate & sodium dehydroacetate
were promising enzyme inhibitors or antienzymes. They have the ability to reduce
the solubility of powdered enamel

III. Substances
which interfere with bacterial growth and metabolism:Includes:-

• Urea and ammonium compounds

• Chlorophyll

• Nitrofurans

• Antibiotics

• Caries vaccines

 

Nutritional measures
include:

The chief nutritional measures advocated for the control of
dental caries is restriction of refined carbohydrate intake. Other measures
include

    Avoiding sugar
that retains of teeth surface

    Avoiding sugar in
between meals

    Eating of
phosphate diets

Mechanical measures
include:

This refers to procedures specifically designed for and
aimed at removal of plaque from tooth surface methods for cleaning tooth
mechanically are:

1. Prophylaxis by dentist

2. Tooth brushing

3. Mouth rinsing

4. Use of dental floss or tooth picks

5. Incorporation of detergents foods in diet

6. Pit and fissure sealants

To prevent the dental caries and to maintain the oral
hygienic many substances are used like ammoniated toothpaste, urea-containing
powders, and antibiotic containing mixtures and anti- enzyme compounds but
however these compounds have their own advantages and limitation according to
the council on dental therapeutics.

A currently accepted and documented approach to prevent
caries is administration of fluoride either internally or topically to the
teeth.

Role of fluorides:

To prevent caries, most accepted and documented theories are
based on the usage of fluoride either internally or externally.

    Fluorides are
found in soils rich in fluorspar,cryolite,and other minerals.

    Fluoride is a
mineral found throughout the earth’s crust and widely distributed in nature.

    Fluoride is the
ionic form of the element fluorine

    Sources: Small
amounts: Fruits, vegetables, cereals.

    Rich amounts: Sea
foods and tea leaves, Fluoridated Salt / Milk

    Topical agents:
Toothpaste

    According to WHO:
Water is the chief Source of Fluoride ions

Distribution of Fluorides:

Teeth and skeleton have the highest concentrations of
fluoride. –Due to the affinity of fluoride to calcium.

Fluoride content of teeth increases rapidly during early
mineralization periods and continues to increase with age, but at a lower rate

Metabolism of fluoride ions:

When taken internally, fluoride in solution or in rapidly
soluble salts is absorbed almost completely from the GIT. The absorbed fluoride
is partially deposited in the bone or developing teeth, remaining excreted by
kidneys.

Careful analysis of teeth has shown that the concentration
of fluoride is greater in the surface layer of enamel in both erupted and
unerupted teeth. Thus fluoride uptake from tissue fluids is limited to external
surface. The deposited fluoride on the surface of the teeth does not allow the
action of acids or enzyme in producing lesions. Before studying the theories, let
us study the role of fluoride in teeth

Presence of fluoride ions in teeth

Fluoride: identified as one of the elements present in
dental hard tissues.

•Fluoride ion is “calcium –seeking”

•Apatite: the principal mineral of skeletal tissues.
Crystallized form of calcium phosphate: Ca10(PO4)6(X)2. If:

‘X’ is OH hydroxyapatite

‘X’is F fluoroapatite : more regular

Fluoride
Concentration in Teeth

• It is estimated that substitution of only 10% of hydroxyl
groups in enamel apatite by fluoride, renders the enamel maximally resistant to
caries

• Concentration of fluoride is higher:

    On the surface
enamel compared to the deeper layer,

    In permanent
teeth compared to decalcified teeth formed under the same circumstances

The possible theories are for preventing dental caries by
fluoride ions:

1: Fluoride were
incorporated into tooth structure:
Increased resistance to acid attack by
the following mechanism

a) Fluorapatite forms more compact and regular crystals than
hydroxyapatite (Fluoride favours formation of fluorapatite, a more acid –
resistant apatite than hydroxyapatite) and present in less surface area for the
action of acids

b) Higher concentration of fluoride on outer enamel can
protect against acid attack

2: Fluoride influence
the solubility rate:
Calcium and fluoride ions released from the apatite
during initial dissolution forms Calcium Fluoride (CaF2) on the surface of the
fluorapatite hence reducing it solubility.

3: Fluoride catalyses
stable apatitic phase:
Fluoride ions replace carbonate ions in the apatite
structure. Apatite crystals with low carbonate contents are more stable and are
less soluble compared to those with high carbonate ion content.

4: Fluoride favors
remineralization of early carious lesions

• Plaque fluid contains fluoride. At decreased pH the
fluoride level increased.Enhance remineralization of enamel by facilitating the
re-precipitation of calcium and phosphate ions into the enamel fluoroapatite.

• Greater concentration of fluoride released from the
dissolved enamel or already present on the plaque, the more will
remineralization be favored and carious process be slowed. Use of topical
fluoride raises the fluoride level of tooth surface and underlying tissues to a
level expected to protect against caries.

5: Effect on acid
production:

Fluoride 
inhibits  enolase  and 
ATP-ase  activity  (Embden-Meyerhof  pathway 
in  bacterial metabolism) in oral
streptococci hence reduce acid production.

Fluoride can bind more effectively to positively charged
areas on the apatite crystal than can the bacteria.

Adversely affects the uptake of glucose by bacteria into the
cells and subsequently lactic acid formation.

Further prevent the synthesis of glycogen

6: Fluoride affects the morphology of the teeth making them
more self- cleansing

Fluoride administered during tooth formation may result in
shallower and wider fissures, more rounded cusps thus reducing the number and
size of sites where food and plaque could accumulate.

7. Different agents with specific effects: For example:
Stannous ions in SnF2may affects surface wettability and reduce plaque
formation because of its high solubility.

The  mechanism  of 
action  by which  fluoride 
inhibits  the  caries 
formation  is  still 
to  be completely analyzed.

Fluoride therapy:

Systemic: water
fluoridation

Topical:
Fluoridated tooth paste/tablets

Systemic: water fluoridation: Fluoride ions are
present in food and ground water. But in some places the ground water does not
contain fluoride ion. So municipal people add fluoride ion to the drinking
water. This process is known as fluoridation. In case if too much of fluoride
is present in tissue fluids it leads to mottling of teeth (dental fluorosis).
This usually occurs in those areas where the drinking water has more than 2ppm
of fluoride.

Fluoridated Milk –
Milk is used as an instrument for fluoride administration. – Fluoridated milk
was found to be as effective as fluoridated water in reducing dental caries.

Fluoridated Salt –
Use salt as a vehicle for fluoride in the diet. – Salt is about 2/3 as
effective as the water.

Topical: Fluoridated tooth paste/tablets:

Fluoride Tablets –
Ingestion daily beginning at 5 – 9 years: permanent teeth can still be
significantly protected from caries.

Prenatal Fluoride
Supplement –
Fluorides supplements are not recommended for adults,
especially pregnant women, for reducing dental caries. The concentration of
fluoride that reaches the fetus is generally lower than that in the maternal
blood. Infants exposed will have higher plasma, skeletal and developing enamel fluoride
levels.

Anti caries agent:
Anticaries are those inorganic compounds used to prevent the dental caries. The
official inorganic compounds used as Anticaries agent is: Sodium fluoride

Monograph analysis of
sodium fluoride.
Sodium Fluoride

Molecular formula:
NaF

Mol. Wt: 41.9

Standards: Sodium
Fluoride contains not less than 98.5 per cent and not more than 100.5 per cent
of NaF, calculated on the dried basis.

Description. A
white powder or colourless crystals.

Synonyms:
Floridine; sodium monofluoride; disodium difluoride; natrium fluoride; Florocid

Physico chemical
properties:

• Sodium fluoride is soluble in water.

• Noncombustible.

• Corrosive to aluminum

Method of Preparation:

NaF is prepared by neutralizing hydrofluoric acid using
sodium hydroxide

Chemical reaction:

HF + NaOH → NaF + H2O

Hypersensitivity by
definition:
A state of being excessively sensitive to a substance

• DENTINHYPERSENSITIVITY is characterized by short sharp
pain arising from exposed dentin in response to stimuli mainly thermal, evaporative,
tactile, osmotic or chemical—that cannot be ascribed to any other dental defect
or disease.

• Dentine hypersensitivity is sensation felt when the nerves
inside the dentin are exposed to the environment

Effect of sensitivity

• The sensation can range from irritation all the way to
intense, shooting pain.

• This sensitivity can be caused by several factors,
including, decaying teeth or exposed tooth roots.

Desensitizing agents

• Desensitizing agents are used to treat the sensitive of
dentin towards too hot or cold condition

The inorganic compound used as desensitizing agents are zinc
eugenol cement

Chemical Composition:

     Zinc oxide:
69.0%

     White Rosin:
29.3%

     Zinc acetate: 1%

     Zinc sterate:
0.7%

     Liquid eugenol:
85%

Classification of
zinc eugenol cement:
Type I ZOE: For temporary cementation Type II ZOE:
Permanent cementation

Type III ZOE: Temporary filling and thermal base

Type IV ZOE:  Cavity
liners

    It is available
in the form of Powder/liquid/paste

 

Storage: Store in a suitable container

Medicinal uses:

     Temporary
cementation

     Permanent
cementation

     Pulp capping
agent

     Cavity liners

Dentifrices: -Used to
clean the accessible surface of the teeth and the adjacent gums

    Also called as
cleaning agents

    Applied with the
fingers or tooth brush

    Mainly used for
destaining the teeth

    Inorganic
compound used is calcium carbonate

The different types
of dentifrices

Cleaning agent or dentifrices: They are the material used to
clean the teeth and adjacent gums by abrasive property and the rubbing force.
They are applied either by fingers or toothbrush. Dentifrice are applied as
tooth powder or tooth paste, some of the useful substances used as dentifrices
for providing the oral hygienic condition are fluoride, calcium salts,
phosphate salts, etc.

Dentifrices
containing polishing agent:

Dentifrices should not only have the property of cleaning
teeth but also should remove the stains on the teeth so that it looks white,
this can be possible only if the dentifrices are containing the polishing agent
in its preparation. The official product used as polishing agent is pumice, a
substance of volcanic origin mainly containing silicates of aluminum, potassium
and sodium.

Dentifrices containing desensitizing agent: They are the
dental products that reduce the sensitivity of the teeth towards heat and cold.
Therefore some desensitizing agents are used in dental preparation.

The mechanism of action of these agents may be due to local
anaesthetics. Examples of these agents are calcium chloride

Oral  antiseptics 
and  astringent
:  For 
maintaining  the  oral 
hygienic  some  inorganic compounds are used for their
antiseptic or astringent activity.

For examples:

1. Hydrogen per oxide, I.P.: 3% is used as antiseptic

2. Sodium per borate: 2% is used as tooth powder or as
mouthwash.

3. Magnesium peroxide: Rarely used as bleaching agent.

4. Ammonical silver nitrate solution: used as astringent.

5. Zinc oxide: used as cement and fillers.

 

The general
requirements for a dentifrice as follows:

     Should be
capable of cleaning the teeth

     Leave a
pleasant, cool and refreshing sensation in the mouth

     Harmless,
nontoxic, non-irritant

     Maintain its
flow properties

     Easy to pack and
use

     Abrasive character
should be of standard limit

Monograph of calcium
carbonate Name:
Calcium carbonate Chemical formula: CaCO3

Molecular weight:
100.09 g/mol

Properties of calcium
carbonate:

Description: A
fine, white, microcrystalline powder. odorless

Solubility:
Slightly soluble in water, freely soluble mineral acid with liberation of
carbon di oxide gas.

Standards:
Calcium Carbonate contains not less than 98.0 per cent and not more than 100.5
per cent of CaCO3, calculated on the dried basis

Synonyms:
Precipitated Chalk

Method of Preparation:

Calcium carbonate is prepared from calcium oxide. Water is
added to give calcium hydroxide, and carbon dioxide is passed through this
solution to precipitate the desired calcium carbonate, referred to in the
industry as precipitated calcium carbonate

Chemical reactions:
CaO + H2O → Ca(OH)2

Ca(OH)2 + CO2 → CaCO3

Storage: Store
protected from moisture

Medicinal uses:

    Dentifrices

    Calcium
Supplement

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