Discoloration

DISCOLORATION
and
its MANAGEMENT

Contents
• Introduction
• Classifications
• Extrinsic discolourations
• Intrinsic discolourations
• Tetracycline discolourations
• Enamel hypoplasias
• Management

Contents
• Management of
Extrinsic stains
1. Prophylaxis
2. macroabrasion
• Management of
Intrinsic stains
1.Microabrasion
2.Bleaching
• Non-Vital Bleaching
• Vital Bleaching
3.Composite Resin
Restorations
4.Porcelain Veneers
Combination Management

Introduction
• Tooth colour varies between the edge
and the neck of the tooth, from one
group of teeth to the next, and from
person to person.
• Incisal /occlusal 3rd
• Middle 3rd
• Cervical 3rd

• Only enamel alone is not responsible for
the colour of the tooth, four dental tissues
are involved in creating the final shade.
• Teeth are formed of :
1. Pulp, vital non-mineralised but richly
innervated and vascularised;
2. A layer of Dentin situated around the
pulp, thickens with age, with a rate of
apposition of approximately 4
micrometres per day. Consequently, teeth
take on a deeper shade with time;

3. Enamel, which covers the dentin in
the coronal portion of the tooth;
4. Cementum, which covers the dentin
in the root of the tooth – the colour of
the cementum is involved quite late
in the overall shade of the tooth, as it
only appears in cases of
dysfunctional upper lips, and after
gingival recession.

• Tooth colour is determined by certain physical
properties of enamel and dentin, and successive
stages of dental tissue development.
• Studies show that dentin plays major part in final
shade of a tooth.
• Various assumptions and experimental evidence
have led to the conclusion that enamel has a certain
degree of translucency, but no intrinsic colour.

Enamel as a „bioglass‟
• Enamel acts as a bioglass that filters the natural colour
of the dentin.
• With regard to physical properties, tooth colour
depends on the trajectory of the light that hits the
tooth, on how this trajectory is deviated and on how
the light is absorbed.

Ingle defines tooth discoloration as
“Any change in the hue, colour or
translucency of a tooth due to any
cause; restorative filling materials,
drugs ( both topical & systemic),
pulpal necrosis, or hemorrhage may
be responsible.”
Tooth discoloration

Ingle classifies tooth discoloration acc. to etiology:
Patient related
cause
Dentist related
cause
Pulp Necrosis
Intra-pulpal hamorrhage
Pulp tissue remanants
Calcific metamorphosis
Age related
Intracanal medicaments
Obturating materials
Developmental defects in
tooth structure
•Enamel hypoplasia
•Dental fluorosis
•Eryththroblastosis fetalis
•AI & DI
Amalgam
Pins & posts
Tetracyclines Resin composites

Extrinsic Staining
• Located on the outer surface of teeth
• The etiology for extrinsic stains include:
– Non-enzymatic browning (maillard reactions which are the
natural process of degradation of glycosylated proteins),
– protein denaturation,
– formation of pigmented metal sulfides,
– precipitation of dietary chromogens and their subsequent
incorporation into the salivary pellicle.

Classifications
The Nathoo classifies extrinsic dental stain under
3 categories as follows :
• Nathoo type 1 (N1) direct dental stain : N1-
type colored material (chromogen) binds to the
tooth surface. The color of the chromogen is
similar to that of dental stains caused by tea,
coffee, wine, chromogenic bacteria, and
metals.

• Nathoo type 2 (N2) direct dental stain : N2-type
colored material changes color after binding to the
tooth. The stains actually are N1-type food stains that
darken with time.
• Nathoo type 3 (N3) indirect dental stain : N3-type
colorless material or prechromogen binds to the tooth
and undergoes a chemical reaction to cause a stain. N3-
type stains are caused by carbohydrate-rich foods (eg,
apples, potatoes), stannous fluoride, and chlorhexidine .

• Classification based on origin of stain
– Non-metallic
– Metallic in origin.
• Non-metallic extrinsic stains arise from chromogens
released into the oral cavity during ingestion of
dietary components, beverages (specifically coffee
and tea), mouth rinses, medicaments, or the habitual
use of tobacco products. These dietary chromogens
get absorbed into dental plaque or the acquired tooth
pellicle.

– Chlorhexidine antiseptic mouth rinse has been observed
to cause diffuse brown staining with prolonged use
especially around composite restorations.
– Tobacco staining results from the deposition of tar
products on the tooth surface and may penetrate enamel.

• Metallic stains have been reported to be associated
with occupational exposure to metallic salts and
dietary supplements that get incorporated into dental
plaque and acquired pellicle.
– Black staining has been linked to individuals using
iron supplementation and iron factory workers.
– Green staining has been seen on the teeth of
factory workers exposed to metallic copper as well
as mouth rinses containing copper salts.

• Data regarding the role of oral chromogenic
bacteria leading to tooth discoloration has not
been substantiated in the literature. As a result its
location on the external tooth surface substrates,
external stains overall have relatively good
prognosis.
• The extrinsic staining of teeth is a growing
esthetic concern for business, social, and other
reasons. The consideration attached to stained
teeth correlates to poor oral and general hygiene.

Intrinsic discoloration
• Intrinsic discoloration can be defined as discoloration which is
incorporated into the structure of either enamel or dentine and which
cannot be removed by prophylaxis with toothpaste or pumice.
• It can be a significant cosmetic, and in some instances, functional,
problem.
• Loss of vitality secondary to trauma or infection frequently results in
tooth discoloration which is not responsive to conventional
endodontic therapy.
• Similarly fluorosis, tetracycline staining, localised and chronological
hypoplasia, and both amelogenesis and dentinogenesis imperfecta
can all produce a cosmetically unsatisfactory dentition.

History
• Specifically:
• Details of the mother‟s obstetric history and the delivery;
• Medical history including neo-natal or early childhood illness
and any drugs taken;
• Dental history - infections relating to primary teeth; trauma to
the primary and permanent teeth;
• Family history of discoloured or abnormal teeth;
• Fluoride history including supplementation, residence in
natural water fluoridation areas,
• Tooth-brushing habits including the amount of paste used, the
type of paste in childhood and any admitted swallowing of
paste.

Etiology
Within Enamel:
• Local: caries; idiopathic; injury/infection of primary predecessor;
internal resorption.
• Systemic: amelogenesis imperfecta; drugs,eg.Tetracycline;
fluorosis; idiopathic; systemic illnesses during tooth formation.
Within Dentine:
• Local: caries; internal resorption; metallic restorative materials;
necrotic pulp tissue; root canal filling materials.
• Systemic: bilirubin (haemolytic disease of the newborn); congenital
porphyria; dentinogenesis imperfecta; drugs,eg.Tetracycline.

Clinical examination
• Specifically –
• Both dentitions are affected or not,
• Whether all teeth in one dentition are equally affected.
• Whether or not there is a symmetrical or chronological pattern.
• If possible, the extent of discoloration should be identified
with respect to the depth of affected enamel or dentine.

Tetracycline discolouration
• Tetracycline broad-spectrum antibiotics - introduced in 1948
• Used for treatment of many common infections found in both
children and adults.
• Tetracyclines - its compounds consist of four fused cyclic rings
• Many systemic side effects – pregnant women are particularly
susceptible to tetracycline-induced hepatic damage (Madison
1963).
• It also crosses the placenta and has toxic effects on the
developing foetus-therefore contraindicated during pregnancy.
• Tetracycline antibiotics are still commonly used in the
treatment of acne in adolescents and young adults. This long
term use of tetracycline in particular Minocyline (Minocin)
which is a semi synthetic tetracycline derivative can also cause
staining of the adult teeth (Cheek and Heymann 1999).

Effects of tetracyclines on teeth
• One of the most obvious and well-documented side-effects of
tetracycline use is it‟s incorporation as a fluorescent pigment into
tissues that are calcifying at the time of administration.
• It has the ability to chelate calcium ions and to be incorporated
into teeth, cartilage and bone, to form a tetracycline-calcium
orthophosphate complex (Eisenberg 1975) resulting in
discoloration and enamel hypoplasia of both the primary and
permanent dentitions if administered during the period of tooth
development.
• The severity of the discolouration is considered to be related to
dose, frequency, duration of therapy and critically the stage of
odontogenesis.

• The administration of tetracycline to pregnant women
must be avoided during the second or third trimester of
gestation and to children up to eight years of age
because it may result in discoloration and enamel
hypoplasia (Conchie 1970).
• The drugs should not be given to nursing mothers, as
they are also excreted in human milk (van der Bijl
1995). Adult-onset tooth discoloration following long-
term ingestion of tetracycline (Di Benedetto 1985) has
also been reported.

• The discoloration is permanent and varies from yellow or gray to
brown depending on the dose or the type of the drug received in
relation to body weight.
• After tooth eruption and exposure to light, the fluorescent yellow
discoloration gradually changes over a period of months and
years to a non-fluorescent brown color.
• The labial surfaces of yellow-stained anterior teeth will darken
in time while the palatal surfaces and buccal surfaces of
posterior teeth will remain yellow. These changes are due an
oxidation product of tetracycline, which is light induced
(Bevelander 1961; Atkinson 1962) The affected teeth will also
fluoresce bright yellow under UV light in a dark room.

• Feinman et al. (1989) - clinical classification of the various degrees of
tetracycline staining, indicating for each category the treatment prognosis:
I. First degree staining: minimal,
uniformly distributed, light yellow,
light brown or light grey discoloration,
restricted to three quarters of the incisal
part of the crown. Good treatment
prognosis.
II. Second degree staining: staining varies
more in quantity and location, ranging
from deep yellow to brown or grey with
no banding. Treatment prognosis is
variable, as it depends entirely on the
intensity of the staining.

III. Third degree staining: dark
brown, dark grey, purple or
blue staining with marked
banding. Prognosis for an
efficient and aesthetic outcome
is not good, although teeth may
be lightened to some degree.
IV. Fourth degree staining: intense
pigmentation combining very
dark stains with highly
pronounced bands. Bleaching
is inefficient in such cases.

ENAMEL HYPOPLASIA
• Its a defect in tooth enamel resulting in less quantity of
enamel than normal.
• The defect can be a small pit or dent in the tooth or can
be widespread that the entire tooth is small and/or mis-
shaped.
• It may cause sensitivity, may be unsightly or may be
more susceptible to dental caries.
• Can occur one tooth or on multiple teeth.
• It can appear white, yellow or brownish in color with a
rough or pitted surface.

• Environmental, genetic factors that interfere with
tooth formation may cause EH.
• Includes trauma to the teeth and jaws,
• Intubation of premature infants,
• Infections during pregnancy or infancy,
• Poor pre-natal and post-natal nutrition,
• Hypoxia,
• Exposure to toxic chemicals and a variety of
hereditary disorders.

• Prophylaxis
– The science and practice of preventing the onset of
diseases of the teeth and adjoining mouth tissues.
It involves removing bacterial plaque, food debris,
stains, and calculus from the crowns and roots with
hand scaling or ultrasonic scaling instruments and
hand or electric polishers.

Macroabrasion
• Indicated for removal localized surface stains
• 12 fluted composite finishing bur or a fine grit
finishing diamond is used.
• Light intermittent pressure is applied to avoid
unnessecary removal of tooth structure.
• After removal of defects 30 fluted composite
finishing bur removes any striation on the
surface
• Surface is polished byabrasive rubber points.

Intrinsic stains
• Microabrasion
• Bleaching
– Non-Vital Bleaching
– Vital Bleaching
• Composite Resin Restorations
• Porcelain Veneers

Microabrasion
• Involves the removal of a small amount of surface enamel
• Classically incorporates both „abrasion‟ with dental instruments
and „erosion‟ with an acid mixture, the term „abrosion „ has been
used by some authors.
• Superficial demineralisation.
• Modifies the optical properties of enamel.
• The treated enamel no longer reflects or refracts light in the way it
used to, thus hiding the underlying stains.

• There are two main techniques for
microabrading discoloured or hypoplastic teeth.
– hydrochloric acid/pumice technique
– phosphoric acid/pumice technique
• These techniques are simple to perform and the
depth of enamel removed in 10 applications is
approximately 100 μm. (0.1 mm.). If a
satisfactory clinical outcome is not achieved the
technique should not be repeated but an
alternative treatment is selected.

• Microabrasion is indicated for fluorosis, post-
orthodontic demineralisation, localised hypoplasia
due to infection or trauma, and idiopathic hypoplasia
where the discoloration is limited to the outer enamel
layer.
• Analysis of the effectiveness of microabrasion should
be delayed for approximately one month post-
treatment, as the appearance of the teeth will continue
to improve during this time.
• Pre-operative sensitivity tests, radiographs and
photographs are advised.

Hydrochloric Acid / Pumice
Microabrasion
i. Clean teeth with pumice, water, wash and dry.
ii. Isolate - rubber dam and either apply vaseline to the
gingiva prior to rubber dam application or paint
Copalite varnish around the necks of the teeth after
dam application.
iii. Mix 18% hydrochloric acid with pumice into a slurry
and apply a small amount to the labial surface with
either slowly rotating rubber cup, a wooden stick or
flat plastic instrument over the surface for 5 seconds.
Wash for 5 seconds directly into the aspirator. Repeat
until the stain is reduced, up to a maximum of 10 x 5
second applications per tooth. Any improvement
possible will have occurred by this time.

iv. Apply fluoride drops to the teeth for 3 minutes.
v. Remove the rubber dam.
vi. Polish the teeth with graded Soflex discs or
polishing pastes.
vii. Polish the teeth with fluoridated toothpaste for
one minute.
viii.Review in one month for sensitivity tests and
photographs.
ix. Review in six months to check pulpal status.

Phosphoric Acid / Pumice Microabrasion
i. Apply phosphoric acid 35% to enamel surface for
30 secs, wash and dry.
ii. Remove frosted enamel with tungsten carbide
composite finishing bur using minimal pressure,
until a shiny enamel surface reappears.
iii. Clean teeth with pumice and water slurry in a
slowly rotating rubber prophylaxis cup, and then
wash again.

• McInnes Microabrasion technique
• McInnes solution is used, it‟s a mixture of
o 30% Hydrogen peroxide – 5 parts (bleaches tooth)
o 36% Hydrochloric acid – 5 parts (etches enamel)
o Diethyl ether – 1 part (acts as solvent, stabilzes the
solution)
• Modified McInnes solution contains 20%
Sodium hydroxide instead of Hydrochloric
acid

BLEACHING
• It‟s a treatment modality involving an oxidative
chemical that alters the light absorbing nature of a
material structure, thereby increasing its perception of
whiteness.
• The chemical oxidation-reduction reaction takes place
between the colouring substance (reducing agent) and
the bleaching molecule (oxidising agent).

Tooth
Reducing
agent takes up
electron
Bleaching agent
Oxidizing agent
gives free electron
Free reactive radical
reacts with the
unsaturated bond
Simpler molecules
are formed
Reflects less light or
becomes colorless
Larger stain molecules
are converted to smaler
ones

• Oxidation reaction - molecular oxygen that penetrates
into the mineralised dental tissues without altering
them and degrades the pigments responsible for their
coloration.
• The oxygen molecules enter the organic enamel-
dentin matrix and react with the organic molecules,
i.e. dissociate the pigments by modifying the long
dark-coloured molecular chains and splitting them
into smaller and lighter-coloured molecules.

Ideal bleaching agent
1. It should have neutral pH.
2. It should be easy to apply, maximum patient
compliance.
3. It should not irritate or dehydrate oral tissues.
4. It should not cause any adverse effect to the teeth being
bleached.
5. It should adhere to tooth structure i.e., controllable flow
6. It should have contrasting colour with the oral structure
7. Should have adjustable peroxide concentraion
8. It should give desired results within short time
9. Be well controlled by dentist to customize the t/t to the
patient‟s need.

BLEACHING AGENTS
SODIUM DIOXIDE
• Historical interest - limited use.
• When sodium dioxide is combined with water, the
reaction yields sodium hydroxide and oxygen:
Na2O2 + H2O → 2 NaOH + 1/2 O2
• The molecular oxygen produced is a powerful antiseptic
and bleaching agent.
• When used in high concentrations on pulpless teeth, it
has strong caustic effects that render it dangerous for the
periodontium.

CHLORINE AND CHLORINE
DERIVATIVES
• Chlorine acts indirectly as it is capable of
releasing the oxygen from a water molecule:
Cl2 + H2O → 2 HCl + 1/2 O2

HYDROGEN PEROXIDE
• It is the main bleaching agent used for tooth
whitening, produced by the following reaction:
H2O + 1/2 O2 → H2O2
• The resulting molecule is unstable and ready to split
and release a molecule of oxygen.
• The concentrations of H2O2 solutions are usually
given in percentages or in volumes that indicate the
quantity of oxygen released as a result of the
breakdown reaction.

• Because molecular dissociation occurs differently depending
on the pH, the efficacy of H2O2 can be improved by modifying
the pH of solution.
• In an alkaline solution, the hydroxyl groups neutralise the
protons and accelerate the bleaching process (Frysh, 1995).
• The consumption of an element produced by the oxidation-
reduction reaction will modify the balance, leading to the
yielding of highly reactive HO2-, a molecule with a low
molecular weight, far more oxidative than molecular oxygen,
and which diffuses easily through the enamel barrier.

SODIUM PERBORATE (BO3Na 4H2O)
• Its a fine white powder, which is antiseptic and chemically
stable when anhydrous.
• When combined with water, it reacts to produce metaborate
(BO3NA) and molecular oxygen:
Na2 [B2(O2)2(OH)4] + 2H2O → 2NaBO3 + 2H2O2
BO3Na + H2O → 1/2 O2 + H2O
• Metal peroxides, persulphates, calcium perborate and
magnesium perborate (acting as anion breakdown activators)
may also yield molecular oxygen, and are used by some in
preference to sodium perborate.
• The final product is an oxidising molecule produced by the
breakdown of the hydrogen peroxide.

CARBAMIDE PEROXIDE (H2NCONH2) a.k.a
UREA-HYDROGEN PEROXIDE
• Approved by FDA as an oral antiseptic in 1979 and as a
medicament in 1991.
• It is the most widely used vital-tooth bleaching product.
• Obtained by the syncrystallisation of H2O2 and urea into
colourless and odourless crystals.
• Its chemical formula contains about 30% hydrogen
peroxide. In other words, a 10% carbamide peroxide
solution breaks down into 3% H2O2 :
H2N -CO-NH2* H2O2 → H2NCONH2 +H2O2
In water

• Carbamide peroxide yields urea, that further
decomposes into CO2 and ammonia.
• A high pH facilitates the bleaching process, i.e.
in an alkaline solution, the formation of free
radicals requires less energy, and the reaction
yield is higher, with larger quantities of H2O2
being produced than in an acidic solution.

ADJUVANTS
 Improve the efficacy of tooth bleaching products.
 Not always clearly mentioned by manufacturers:
• Thickeners such as carbopol (acrylic acid polymer resin),
which help to maintain contact between the gel and the dental
tissues as long as possible and thus allow a progressive release
of the oxidising agents;
• Urea, which stabilises the hydrogen peroxide, increases the
solution pH, and has an anti-cariogenic effect;
• Glycerine, which increases the viscosity of the preparation and
facilitates its manipulation. The only problem is the tooth
dehydration it incurs;
• Stabilisers (e.g. Citroxain, citric acid, phosphoric acid), which
increase the shelf-life of bleaching products;
• Flavourings, which make the products pleasanter to use.

Bleachin
g
Vital
At
home
In
office
Thermo/ Photo
bleaching
Non
Vital
Walkin
g
bleach
In
office
Thermo
catalytic
UV Photo-
Oxidation
Intentional
endo t/t &
Intracoronal
bleaching

VITAL TOOTH BLEACHING
Indications
• Moderate tooth discoloration – Healthy teeth with
perfectly sealed coronal fillings (preferably composite resin
fillings), and teeth with no significant structural defect.
• Discoloration related to genetic disorders;
• Permanent acquired discoloration:
– Fluorosis staining, with stains ranging from simple, white,
opaque spots to a darker discoloration, or other types of
staining caused by an excessive intake of fluoride.

• Discoloration related to the physiological aging of teeth
• Post-traumatic discoloration (vital tooth with sclerotic
dentin).
Relative indications
• Improvement of the teeth's natural colour before the
placement of a prosthetic restoration in the adjacent area.
The patient should be warned that the lighter colour obtained after bleaching
has a limited lifespan and that the procedure may eventually have to be repeated
to adjust the colour of the ageing natural teeth to that of the prostheses.

Relative contraindications
• Very pronounced tooth stains with a dull and saturated
coloration, where "colour bands" are visible, treatment in this case
is a prosthetic alternative, i.e. the application on the affected teeth
of a thin layer of covering material (veneer).
• Tooth bleaching will be used here primarily to lighten the
underlying tooth colour, thus limiting tissue destruction and
improving the overall appearance of the restorations (Magne,
1997);
• Teeth with extensive crown fillings;
• Presence of cervical lesions due to wear, and dentin "islands"
caused by occlusal attrition;
• Stains mainly due to permeation by metal salts (amalgam).

• Relative contraindications specific to the night-guard technique
(bleaching trays):
1. Advanced periodontal disease (the bleaching tray must be
trimmed precisely along the gingival margin)
2. Multiple and extensive amalgam restorations or temporary
fillings (IRM) (Rotstein, 1995)
3. Articulation disorders (bleaching tray not suited to these cases)
• Up to date, there are no scientific data to justify any reservations
with regard to bleaching treatments in expectant or nursing
mothers. Pregnancy gingivitis certainly constitutes a relative
limitation, but is not a contraindication.
• The marginal leakage problems that dental restorations may
develop after bleaching can lead to the postponement of these non-
priority treatments.

Absolute contraindications
• Young patients aged under 15-16 (immature tissues and large
pulp volume);
• Teeth that show initial hypersensitivity during the presurgical
clinical examination;
• Teeth with non leak-proof fillings, and initial or recurring caries.
It is an absolute prerequisite to any bleaching treatment that
carious lesions be fully treated and that all restorations fit
perfectly;
• Smoking (possible interactions with peroxides, according to Dahl
and Pallesen, 2003).

VITAL TOOTH BLEACHING
TECHNIQUES
• Vital tooth bleaching procedures, whether performed at home
or in the office, are based on the fact that enamel acts as a
semi-permeable membrane. They are therefore external
procedures. These techniques use the bleaching agent that is
released by the oxidation process, i.e. active oxygen, which
filters into the dental tissues and progressively discolours the
pigments inside the enamel, at DEJ and in external part of
dentin.

At-home bleaching
(Claisse et al., 2000; Ritter et al., 2002; Haywood, 1997; McEvoy, 1989)
• Its aka “nightguard” bleaching technique
involves the use of a mouthguard to deliver the
bleaching agent.
• The first stage of the treatment – after the
possibilities and limits of the technique have
been explained to the patient – is to record the
base line shade of the teeth or to take
photographs of the dentition.

Fabrication of the “bleaching tray”
• Alginate impressions of the arches are made
• Plaster casts are poured
• Reservoirs are made that deliver the bleaching agent, at a distance
of 1 mm from the gingiva. The light-cured resin spacers should be
0.5 mm to 2 mm thick, depending on the technique that will be
used and above all, on the concentration of the product and the
intensity of the stain;

• Thermo forming a polyvinyl sheet over these models;
• Trimming the tray along the gingival line using
scissors once the tray has cooled down – or better
still, directly on the model using a scalpel with an 11
mm blade;
• Smoothing the edges using a micro-torch; –
• Cleaning and cold sterilising the mouthguard before
delivery.

Fitting of the mouthguard and choice of bleaching
product
• The mouthguard should fit the patient‟s mouth
perfectly.
• The tray should be in close contact only with the hard
tissues, as this prevents leakage of the bleaching
product in the area of the gingiva, and encourages an
in-depth action of lower-concentration bleaching agents
(Barghi, 1998; Haywood, 1992).
• The mouthguard should have a constricting effect in the
critical area of the neck of the tooth.

• The operator should choose the bleaching product and
its conc according to the case, and determine the length
of time during which the mouthguard should be worn.
• The active compound is carbamide peroxide, which
breaks down into urea and H2O2. It usually comes as a
gel in a syringe, with conc ranging from 10% to 35%. It
may be combined with thickeners (such as Carbopol)
that slow down the degradation process of the
carbamide peroxide, and with sodium fluoride that
prevents dental sensitivity.

Instructions to the patient
• After thorough tooth-brushing, the patient should use the needle-
tipped syringe to fill the reservoirs with moderate quantities of gel,
• Then place the tray inside the mouth and finally rinse off any gel
that may have leaked onto the gingiva.
• The dentist will determine the length of time the mouthguard
should be worn according to the product used.
• Wearing time will last between three to five hours in one or two
sessions every day, depending on the patient‟s availability and
motivation, on any dental sensitivity observed during treatment,
and on the results aimed at.

• Nightguard systems with concentrations ranging from
10% to 16% are highly effective, owing to the fact
that the salivary flow is reduced at night and that the
bleaching agent & the tooth therefore stay in contact
much longer (Ritter et al., 2002).
• After removal, the mouthguard should be washed in
cold water and the teeth cleaned thouroughly.

Monitoring
• The practitioner should check results every five to six days, in
order to adapt the treatment to changes in tooth-shade and to
clinical signs. To facilitate the monitoring of the process both
by the practitioner and by the patient, and for psychological
reasons. It is recommended to bleach 1st the upper &then the
lower arch.

Outcome
• The outcome depends on
1. The length of time during which the mouthguard is worn,
2. The duration of the treatment
3. Concentration of and sensitivity to the product
4. On the intensity of the staining (Leonard et al., 1998; Matis et al.,
2000). –
• In cases of light staining, teeth are lightened up to 80% in 5-6 days.
• In cases of severe staining (tetracycline), tooth shade may be
improved to a more or less important extent in the first month of
treatment, particularly in the occlusal third, by increasing the
duration of the treatment. In such cases, the at home t/t may be
continued over many weeks,some times even for months.

In-office bleaching
• Used for more severe cases and patients who are “in a hurry”
(Baumgartner et al. 1983; Claisse et al., 2000; Feinman et al., 1989; Goldstein,
1976,1995; Torres-Zaragoza, 1984).
• Many techniques have been developed since the 1970s They
all involve the use of H2O2 in various concentrations:
o Torres-Zaragoza (1984) - 70% H2O2 be used in association with a
reagent, a pH-modifying agent, and a source of heat.
o Goldstein - etched enamel - 35% H2O2 exposed to a beam of light
with an adjustable temperature of 45 to 60 C (Goldstein, 1976;
Goldstein and Garber, 1995).
o Baratieri et al. (1995) employed 35% H2O2 activated by the light of
a curing lamp.

• Chairside bleaching techniques, contain either 15% H2O2 or 35%
carbamide peroxide:
• The in-office protocol starts with proper isolation (rubber dam or
light-cured resin), the barrier should prevent the highly irritant
bleaching agents from reaching the tissues around the teeth.

• After the surfaces selected for t/t have
been cleaned with a paste of pumice,
whiting and water (prophylaxis pastes
should be avoided as they contain
glycerine which reduces the
effectiveness of the peroxide), they are
coated with a layer of bleaching product
that will stay in place for 5 - 30 mins
depending whether or not an activator is
used
• The application is renewed regularly
(three times on average) throughout the
procedure.

• Acc. to some authors, the light from a traditional halogen lamp, a plasma
lamp or an operating lamp placed in close proximity to the tooth
surfaces being treated accelerates the breakdown process and improves
the reaction (Glodstein, 1976; Goldstein and Garber, 1995; Torres-Zaragoza, 1984;
Stabholz et al., 2003).
• Other authors use the light (argon laser) or heat (CO2 laser) produced by
laser beams.
• The outcome is optimised by the cumulated effects of the photothermal,
photomechanical and photochemical reactions.
• The argon laser is particularly effective in treating darker stains. The
CO2 laser is more versatile. However, the heat produced is partially
absorbed (Smigezi, 1996) and appears to be the most harmful feature of the
treatment (Luk and Hubert, 20Tavares et al., 2003).
The use of these devices is considerably limited by their cost.

• At the end of the session, the teeth are thoroughly rinsed,
cleaned and polished, before being coated with a layer of sodium
bicarbonate that neutralises the reaction.
• The bleaching procedure may be repeated 2-3 times on each
dental arch, at an interval of 1-4 weeks and that fluoride is
applied to the teeth for a few days after the treatment, to limit
temporary postoperative hyperaesthesia and to prevent any risks
of pulpal or periodontal complications, which remain
considerable.

• Although these chairside techniques do achieve results,
they are not entirely satisfactory, they are long to carry
out, and often tiresome for the patient, they require
specific and costly equipment (Goldstein, 1976; Goldstein and
Garber, 1995; Torres-Zaragoza, 1984) and, because of their
aggressive nature (Claisse et al., 2000; Luk et al., 2004; Nyborg and
Brannstrom, 1968; Robertson and Melfi, 1980), they can only be
performed and by specialists.

• The latest chairside techniques use compression methods in
conjunction with viscous or compact gels (Miara and Miara, 2003).
The 35% H2O2 bleaching gel (Opalescence Xtra) is placed in a
delivery tray sealed around the gingival margin, where it is
compressed and activated during 10-15 min.
• During the oxygen evolution, the compression and blocking induced
by the perfectly-fitting delivery tray, combined with the use of a
viscous or compact gel, encourages the oxygen ions to migrate
towards the inside of the enamel rather than to be released into the
surrounding air.

• Current techniques use 35% H2O2, combined with a
copolymer, with sodium and calcium fluoride, and
with titanium dioxide.
• These adjuvants give the gel a putty-like consistency
and contrast colour from the gingiva.
• The products used here generally have a slightly acid
pH, rendering fluoridization indispensable at the end
of the treatment to remineralise the treated dental
surfaces and to prevent secondary dentin sensitivity.

Combination bleaching
• Combination techniques achieve faster results than at-home t/t and
are more effective than procedures alone (Zekonis et al., 2003).
• There are two possible options:
I. In the first option, the bleaching procedure starts in the dental
office, to be immediately continued by the patient at home.
II. In the second option, the treatment starts at home and may be
followed by one or two in-office sessions if the stains are
particularly resistant.
• Combination bleaching techniques help to save time without loosing
the advantages of the at home and in-office techniques. Unfortunately,
they also have the same disadvantages as the techniques they
combine.

COMPLICATIONS
• Complications in non-vital teeth
– External cervical resorption
– Secondary crown fractures
– Stain recurrence

• Complications in vital teeth
– Post-operative sensitivity
– Enamel surface alterations
– Effects on dental restorations
– Stain recurrence
– Effects on the oral mucosa (caustic & cytotoxic
effects)

• A study was done to evaluate Bleaching
efficacy of whitening agents activated by
xenon lamp and 960-nm diode radiation & it
was concluded that both are effective to
provide brighter teeth. However, according to
the conditions used in this study, only the
xenon arc lamp induced a safer temperature
increase. (LASER JOURNAL 2/2005)

• A study was done using
Group 1 H2O2 (35%)
Group 2 Curing light
Group 3 LED
Group 4 LASER
& results were compared with Vita Easyshade
Spectrophotometer that showed equality
between shades of no statistical significance
Operative dentistry 2008, 33-1, 15-

NON-VITAL TOOTH BLEACHING
Indications
• Any discoloration secondary to:
– a loss of pulp vitality, and more particularly to a pulp
haemorrhage or to the decomposition of residual pulp
tissues that were not removed during root canal therapy
(pulp horns).
– the use of medication, or the placement of root canal filling
materials or non leak-proof restoration materials.
• Blackish coloration of the root, which is visible under a thin
gingiva. The bleaching treatment will have to reach deep into
the root.

Relative contraindications
• Stains incurred by root canal filling pastes (phenolic resins,
radiopacifiers) or metal salts (amalgams), for which treatment
prognosis is guarded.
• Teeth with extensive crown restorations.
Absolute contraindications (Particularly for hydrogen
peroxide-based techniques)
• Permanent teeth in children and young adolescents;
• Teeth that have undergone a periodontal treatment and root
planing procedure;
• Traumatised teeth (luxation, avulsion, intrusion...);
• Teeth that show external or internal root resorption.

NON-VITAL TOOTH BLEACHING
TECHNIQUES
• Rely on the permeability of the dentin, which
allows the oxidising agent to reach the pigments
directly, the latter being concentrated mostly
(according to some authors) at the dentin -
enamel-junction. Prognosis is usually extremely
good when case selection is correct.

• The bleaching protocol starts with a
1. Thorough clinical examination of the tooth and
surrounding supporting tissues.
2. X-rays are - assess the quality of the endodontic treatment
and to visualise any root and/or periodontal defects.
3. Photographs are taken to keep record of the state of the
tooth prior to treatment.
4. Conscent - to guarantee that all legal and ethical
obligations are met, the practitioner gives the patient a
precise quote for the bleaching treatment, as well all the
usual recommendations and any other relevant
information.

• Non-vital tooth bleaching
– at-home or
– in-office techniques, or
– both techniques in combination.
• For in office procedures, the first phase of the
treatment will focus on the protection of the oral
tissues (Vaseline, dam...) and the preparation of the
tooth.

1. Remove the
gutta percha from the
Coronal portion of
the tooth and sealed
with
the glass ionomer
cement
2.
Remove all
the debris
and surface
stains
3. Place a cotton
pellet saturated with
bleaching solution
into the pulp
chamber
4. Fill the
remaining pulp
chamber with cotton
pellet impregnated
with bleaching paste
5. Seal the pulp
chamber with zinc
phosphate cement
6. After reaching
the desired color,
remove all the
bleaching material
clean the chamber
and fill it with light
shaded composite
resin.

The “Walking bleach" technique
(Claisse et al., 2000; Feinman et al., 1989; Nutting and Poe, 1963; Spasser, 1961)
• It uses a paste of a mixture of sodium perborate and distilled
water (Silvas, 1938) or hydrogen peroxide in a 100 to 130 volume
solution (Bizhang et al., 2003).
• Paste is placed in the pulp chamber & covered with cotton pellet
and sealed with a leak-proof dressing such as Cavit or IRM.
• The paste is left in place for
– 3-6 days if the sodium perborate is mixed with H2O2,
– twenty days if it is mixed with distilled water.
• Commercially available preparations such as Superoxol (30%
aqueous H2O2 solution) or carbamide peroxide may be used, but
gels tend to spread and to weaken the seal formed by the
temporary dressing.

• The combination of sodium perborate and H2O2 achieves rapid
and excellent results, but the technique is contraindicated as it
may cause external cervical resorption.
• The mixture of sodium perborate and distilled water is safe
and risk-free, but less rapid, and results are generally
satisfactory, although the bleaching procedure often needs to
be repeated 2 or 3 times before an acceptable shade is
achieved.

• The final restoration phase is important when composite
materials are involved, as the quality of the bonding will greatly
determine the longevity of the result.
• When products with high concentrations of H2O2 are used, the
residual oxygen that remains after the procedure is finished
momentarily inhibits the polymerisation of the composite resin.
The final restoration should therefore be placed 1 week after the
full completion of the bleaching treatment.

In-office bleaching
• It‟s a.k.a “chairside” or “power” bleaching, uses
an activator such as heat, light or, more recently, a
laser beam.
• In the Thermocatalytic technique, cotton pellets
saturated with 100 or 130 volume H2O2 and
placed in the pulp chamber, where the oxidation
reaction is then activated by heat.
• The tip of the heat-producing inst is placed
directly onto the saturated cotton pellet, resulting
in immediate gas evolution.

• The instrument shouldn't touch the dentinal walls, as this may
cause infractions and secondary fractures.
• The procedure is repeated 5 - 6 times every 5 mins. If the
shade achieved is not satisfactory, a provisional seal is placed
and the treatment is repeated during a later visit.
• While heat activation considerably increases the speed and
efficiency of reaction, it also increases the risk of
complications, which renders this technique obsolete.

• Ultraviolet Photo-Oxidation technique
applies ultraviolet light to the labial surface of
the tooth to be bleached.
• A 30 to 35% hydrogen peroxide solution is
placed in the pulp chamber on a cotton pellet
followed by a 2-minute exposure to ultraviolet
light.
• Supposedly, this causes oxygen release, like
the thermocatalytic bleaching technique.

• A laser beam can activate high conc H2O2 (35%)
extremely quickly and thus help to achieve a
satisfactory lightening of pulpless teeth with
pathological or acquired stains in just 1 or 2
30minute sessions.
• The erbium:YAG laser are used for this type of t/t as
its beams are rapidly absorbed by water.
• Diode lasers that have a deeper penetration depth are
also used, although less frequently because of the
high increases in temperature they induce.

procedure
1. A 35% H2O2 gel is placed inside the pulp chamber and on the
labial and lingual surfaces of the prepared tooth, that is
perfectly isolated.
2. The tooth is then covered with a clear film (e.g. Whitestrip)
fastened to the gingival barrier (light cured protection) so that
the gel remains slightly compressed during breakdown and
stays in place at each new irradiation (frequency: 30 Hz,
energy: 60 M j, distance: 1 to 1.5 mm, duration: 3 seconds;
exposure is repeated 4 - 5 times, with 30-second intervals).

3. Air jet cools the spot where the beam is focused. The gel should
be renewed 2-3 times during the procedure.
4. At end of the session, the gel and the gingival barrier are
removed. Catalase or CaOH should be placed inside the pulp
chamber and left there over 8-15 days prior to the placement of
the final composite restoration so as to neutralise the effects of
the H2O2 (Rotstein, 1993).
• Combination bleaching couples the techniques described above
and is used to treat the most difficult cases. It is efficient but not
without risks and should therefore be excluded from our array of
therapeutic choices.

Composite restorations
• Bleaching factor
• Shade match
• Polishing of restoration
• Staining of restoration,
• Marginal leakage, black lines
• Recurrence of dicolouration
• Bond strength.

Intracoronal protective bleach barrier
• Atleast 2mm thick
• Should follow the contour of the
external epithelial attachment.
• Protective white cement barrier
can be used such as
Polycarboxylate cement, Zinc
phosphate or Glass ionomer
cement, intermediate restorative
material or Cavit.

Systems for extracoronal bleaching

Systems for „In Office Bleach‟

External root resorption
• Increased penetration of bacteria into dentinal
tubules after the bleaching treatment (Heiling et al.,
1995), especially
• Developmental defects or pathological alterations
of the cementum provide bacteria with convenient
entrance routes (Rotstein et al., 1991).
• The permeability of the tooth in the cervical area.
• Assessibility to the cervical area.

Laminate veneers
• The use of laminate veneers (usually ceramic) is
the most commonly-used way of treating
discoloured teeth. Directly-applied composite is
by and large inadequate to mask discolouration

• Difficulties exist in using thin ceramic veneers to mask
extreme levels of discolouration and increasingly, their
use is combined with tooth-whitening conducted over a
considerable period of time prior to tooth preparation.
• If bleaching be carried out it is important to leave a
period of at least two weeks between the final
bleaching and bonding otherwise the bond strength will
likely be compromised (Titley 1988).

• The highest levels of retention occur when a veneer is
bonded to a predominantly enamel substrate (Friedman
1998).
• This can be done in „normal-coloured‟ teeth, in
discoloured teeth, there is risk that the dark shade of
the underlying preparation will shine through the
relatively translucent porcelain.
• To overcome this, include using more opaque ceramics
and luting agents, cutting deeper into the tooth to allow
a greater thickness of overlaying ceramic or
manipulation of the prepared tooth to lighten its shade.

• The principles of veneer preparation should be followed
(Newsome 2008) :
1. Preparation margins should be placed slightly sub-gingivally
and interproximally to hide the transition between veneer
and dark tooth.
2. All margins should be clear, it is usually advisable to break
the contact points to hide the interproximal margins.
3. The shade of the prepared tooth (if possible together with
photographs) should be sent to the laboratory to help them
achieve the best possible result.
4. At the bonding stage it is vital to use a selection of different
water-soluble try-in pastes to determine the most appropriate
shade of luting cement. The more translucent the veneer the
more critical this step becomes.

Full coverage restorations
• The covering layer of porcelain is thicker. Full coverage
also places less reliance on bonding as a means of
retention.
• Although there are usually more aesthetic alternatives for
anterior teeth, zirconia crowns are useful in the treatment
of tetracycline teeth, especially if the preparation has a
deep enough chamfer to allow a sufficiently thick
veneering layer of esthetic porcelain. The need to use
porcelain fused to metal crowns would appear to be
limited except in the most extreme cases where great
strength is an advantage, for example when
parafunctional habits, such as bruxism, are combined
with deep tooth discolouration.

Management of tetracycline discoloured teeth
1. Tooth whitening only
2. Composite bonding (full or partial) over
discoloured areas
3. Combination treatment starting with tooth
whitening and continuing to direct veneers.
4. Laminate veneers (with or without prior tooth
whitening)
5. Full coverage restorations

ENAMEL HYPOPLASIA -
TREATMENT OPTIONS
Treatment for posterior teeth:
1. For sensitive teeth with minimal weardesensitizing agent
can be applied .
2. For mildly hypoplastic molars, place pit and fissure sealant
on the occlusal surface.
3. Remove demineralized enamel and restore with composite.
at 6 month re-evaluation, if composite is lost, replace using
good isolation techniques.
4. Perform minimal reduction of tooth and cement a stainless
steel crown evaluate clinically and radiographically as
indicated
5. For permanent molars, stainless steel crowns are intended
for temporary use only. These teeth should be restored with
a permanent cast crown in the late teen years or early
adulthood.

6. In cases where the first permanent molars are
unrestorable or marginally restorable, extraction prior
to the eruption of the second molars may be a
reasonable alternative.
Treatment for anterior teeth:
1. For sensitive teeth with minimal wear desensitizing
agent can be applied .
2. If there are esthetic concerns, direct or indirect
composite veneers may be bonded to the affected tooth.
3. For permanent anterior teeth, composite or porcelain veneers or
porcelain crowns may be used.

Conclusion
• Teeth being the mirror of a person‟s hygeine to
the society, a discoloration of teeth is seen as
sign negligence.
• Whitening teeth can be a relatively simple way
to have a younger appearing smile.
• It is the obligation of oral health care
professionals to educate the public about the
true economic value and safety of dentist
prescribed whitening treatments.

Probable questions
• Aetiology & treatment of discolored teeth
25 marks
• Discuss causes of discoloration of teeth & discuss
treatment method for Vital discolored tooth.
35 marks
• Discuss various bleaching agents used & discuss
management of Vital discolored teeth.
20 marks

REFERENCES
• INGLE’s Endodontics - 6th edition.
• GROSSMAN’s Endodontic practice - 12th
edition.
• McLaughlin’s Atlas of teeth whitening
• Goldstein’s Esthetics in dentistry Volume 2
• NEVILLE Oral & maxillofacial pathology – 2nd
edition
• TOOTH BLEACHING TREATMENTS - A Review, ADF
Dossiers, Goldberg et al.

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