This document discusses tooth bleaching and discoloration. It begins with an introduction to bleaching and describes common causes of tooth discoloration such as tetracycline use, fluorosis, trauma, and amalgam fillings. It then covers the mechanisms, materials, and methods used in bleaching, including walking bleach techniques, laser activation, and at-home bleaching strips. Potential side effects from bleaching like tooth sensitivity and enamel damage are also mentioned.

2. Bleaching is a treatment
modality involving an oxidative
chemical that alters the light-
absorbing and / or light-
reflecting nature of a material
structure, thereby increasing its
perceptions of whiteness.

3. Introduction
Discoloration
Causes
Bleaching
Indication and contraindication
Mechanism of Bleaching
Bleaching Materials
Intacoronal Bleaching & its adverse effects
Extracoronal Bleaching & its adverse effects
CONTENT

4.  Coffee and tea stains
 Cigaratte
 Diet
 Tobacco
 Nasmyths membrane (seen in children
caused due to reduced enamel
epithelium)

5.  Tetracycline stains
 1st degree
 2nd degree
 3rd degree
 4th degree
 Fluorosis stains
 Trauma to tooth
 Systemic condition
 Erythoblastosis foetalis
 Jaundice
 Amelogenesis imperfecta
 Enamel hypoplasia due to deficiency of vitamin A,C,D.
 Iatrogenic discoloration
 Amalgam
 Intracanal medicaments
(Kerr root sealer, Grossman sealer, Procosol sealer).

6.  more susceptible during the second
trimester in vitro to roughly 8 years after
birth.
 Tetracycline molecules chelate with calcium
and gets incorporated into the
hydroxyapatite crystals.
 Severity of stains depends on the time and
duration of drug administration

7.  1st Degree
 Light yellow, brown stains
 Uniformly distributed
 No banding or localized concentration
 Responds to bleaching in 2 or 3 session
 2nd Degree
 Dark gray stain
 Extensive then 1st degree
 Responds to bleaching in 4-6 session
 3rd Degree
 Dark gray stains with banding.
 Responds to bleaching best bands will be evident.
 4th Degree
 Does not respond to bleaching.

8. 1st Degree 2nd Degree
3rd Degree 4th Degree

9.  High concentration of fluoride in more than 4ppm
cause moderate to severe discoloration.
 Prevalence – Premolars, 2nd molars and mandibular
and maximum incisors.
Types
 Mild Brown:-Pigmentation on smooth enamel
 Responds well to bleaching
 Moderate:-Opaque fluorosis appear gray with
white flecks on enamel surfaces.
 Severe defects :-With pitting and dark
pigmentation with surface Does not respond to
bleaching

10. Mild fluorosis Severe fluorosis

11.  Causes rupture of blood vessel in the pulp.Causing
diffusion of bloodinto dentinal tubules.
 Dark pink immediate after trauma and changes to
pinkish brown after some days
 Causes:
 Haemoglobin degrades into hemin, hematin,
hematoiden and haemosidrin.
 Hydrogen sulphide produced by bacteria combines
with hemoglobin & gives dark colour to tooth

12.  Erythroblastosis foetalis: (Rh factor
incompatibility between mother and
foetus) characterized by – breakdown of
erythrocytes.
 Jaundice: Bluish green or brown stains in
dentin
 Amelogenesis imperfecta: is a genetic
condition which interfere with the normal
enamel matrix formation
 Enamel hypoplasia: caused by deficiency
of vitamins i.e. A, C, D and calcium and
phosphorus

13.  Trauma during pulp extirpation – hemorrhage
 Failure to removal of all pulpal remnants.
 Amalgam restoration cause – dark gray.
 Gold – dark brown when combined with products
of decay.
 Break down of restoration i.e. acrylic, silicate and
composite resins can cause the tooth to look grayer
and discolore
 Silver containing root canal sealers i.e. “Kerr root”,
“grossman sealer”.
 Volatile oils yellowish brown stain

14.  Discolouration of anterior teeth – after R.C.T.
 Tetracycline stains (mild)
 Fluorosis
 Haemorrhagic discolouration
 Discolouration due to ageing
 Medication discolouration
 Hypoplastic or severely undermined enamel
 Deep microcracks
 Sensitive teeth
 Opaque or white spots
 Extensive silicate, acrylic or composite restorations

15.  The active ingredient in tooth bleaching materials
is peroxide compounds.
 Currently a variety of bleaching materials are
available, the most commonly used peroxide
compound are:-
Hydrogen peroxide
Sodium perborate
Carbamide peroxide

16.  HYDROGEN PEROXIDE
 In-office bleaching concentration (typically25% to 38%)
 At-home concentration (3% to 7.5%)
 H2O2 at high concertration.
 Caustic
 Burns tissues on contact
 SODIUM PERBORATE
 Sodium perborate (NaB03 ) is available in powdered form or as various
commercial preparations.
 When fresh, it contains about 95% perborate, corresponding to 9.9% of
the available oxygen.
 Sodium perborate is stable when dry
 Three types of sodium perborate preparations are avail able:
 Monohydrate,
 Trihydrate,
 Tetrahydrate.
 Commonly used sodium perborate preparations are alkaline.
 Material of choice in most intracoronal bleaching procedures

17. CARBAMIDE PEROXIDE
 Exists in the form of white crystals or as a crystallized powder
containing approximately 35% H20 2.
 It forms H202 and urea in aqueous solution.
 Mostly used in home-use bleaching materials with concentrations
ranging from 10 to 30% (equivalent to approximately 3.5% to 8.6%
H20 2)
 Bleaching preparations containing carbamide peroxide usually also
include Glycerine or Propylene glycol, Godium stannate,
Phosphoric or Citric acid, and flavor additives.
 In some preparations, Carbopol, a water soluble Polyacrylic acid
polymer, is added as a thickening agent
 Carbopol also prolongs the release of active peroxide and improves
shelf life

18.  Bleaching Mechanism:
 The mechanism is oxidation / reduction process called as “Redox
process”.
 In this process the oxidizing agent has a free radical with unpaired
electrons, which it gives up, becoming reduced. The reducing agent (i.e.
the substance being bleached) accepts the electrons and becomes oxidized.
 Reducing agent Oxidising agent
 Tooth Bleaching material
 After the PROCESS
 Tooth is oxidized Bleaching material is reduced
 (Organic pigmentation of tooth oxidized)
 In addition to the chemical effect other mechanisms include cleansing of tooth surface
 Temporary dehydration of enamel during the bleaching process, change of enamel
surface.

19.  The methods most commonly employed to bleach
endodontically treated teeth are:
 walking bleach“
 Thermocatalytic techniques.
WALKING BLEACH
is preferred.

20. WALKING BLEACH
Coined by Nutting and Poe in 1961.
 Involves the following steps:
 Familiarize the patient
 Radiographically assess the status
 Evaluate tooth color with a shade guide
 Isolate the tooth with a rubber dam
 Remove all restorative materials from the access cavity,
expose the dentin, and refine the access. Remove all
materials to a level just below the labial-gingival
margin.
 Apply a sufficiently thick layer, at least 2 mm, of a
protective white cement barrier,
 Prepare the walking bleach paste pack the pulp
chamber with the paste.
 Evaluate the patient 2 weeks later

21.  This technique involves placement of the oxidizing chemical, generally
30% to 35% H202 (Superoxol), into the pulp chamber followed by heat
application either by electric heating devices or specially designed
lamps
 Avoid overheating of the teeth and the surrounding tissues.
 Intermittent treatment with cooling breaks preferred.
 In addition, the surrounding soft tissues should be protected with
Vaseline, Orabase, or cocoa butter during treatment to avoid heat
damage.
 Potential damag- external cervical root resorption

22. ADVERSE EFFECT
 External Root Resorption
 Chemical Burns
 Inhibition on Resin Polymerization and
 Bonding Strength

23.  Restoration with a lightshade, light- cured,
acid-etched composite resin.
 Placing white cement beneath the
composite.
 Waiting for at least 7 days after
bleaching, prior to restoring the tooth
with resin composites,recommended.

24.   Extracoronal bleaching may be used for whitening vital or
nonvital teeth as well as a single tooth or whole arch.
 It has experienced a dramatic advancement in materials as
well as techniques after at-home
 AT-OFFICE EXTRACORONAL BLEACHING
  In-office extracoronal bleaching may be perfomed
using a bleaching gel alone or a gel with a light.
 The light source can be a laser (e.g., argon, CO2)
 , halogen, plasma arc, or light-emitting diodes (LED).
 The light exposure is intended to enhance the
bleaching efficacy by activating the bleaching gel
either through a specific catalyst or heat.

25.  LASERS
The action is to stimulate the catalyst in the chemical. There is no thermal effect
and less dehydration of enamel.
 Argon laser: of 488 nm wave-length for 30 seconds to evaluate the activity of
bleaching gel. As the laser energy is applied, the gel is left in place for 3-4 minutes
and then removed. This procedure is repeated for4-6 times.
Argon laser is in the form of blue light and is absorbed by dark colour. Itis an ideal
instrument to be used in tooth whitening when used with 50% H2O2. The affinity to
dark colour ensures that the yellow brown colourcan be easily removed.
 CO2 laser:It is unrelated to the colour of tooth and energy is emitted in the form
of heat. It is invisible and penetrates only 0.1 mm into water and H2O2 where it is
absorbed.
This energy can enhance the effectof whitening after the initial argon laser process.
 Diode laser light:
A true laser light produced from a solid- state source.
It is ultra fast, taking 3-5 seconds to activate The bleaching of agent.
This type of laser produces no heat

26.  Over-the-counter (OTC) tooth bleaching products:
 Available directly to consumers.
 Contains;
 Acid-citric or phosphoric acid
 Gel-acidic ph;applied for 2min
 Post bleach polishing cream- toothpaste containing titanium dioxide
 WHITW STRIP:-
 Which is a thin flexible polyetheline strips which contains 5.3% hydrogen
peroxide in gel form.
 The strips are used for 30 minutes twice daily for 14 days.

27.  TOOTH SENSITIVITY:
 Commonly observed clinical side effect during or afterextracoronal bleaching
of vital teeth, with an incidence of up to 50%
 The sensitivity, usually mild to moderate and transient, often occurs during the
early stages of treatment and usually persists for 2 to3 Days
 Enamel Damage:
 The effect of extracoronal bleaching on enamel has been conducted
mainly using in vitro systems to examine changes in enamel surface
microhardness and morphology.
 Most SEM studies showed little or no morphological changes in the
bleached enamel surface.

28. The amount of mercury release may vary.
Avoid extracoronal bleaching for teeth with extensive
amalgam restorations.
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