1. VITAL TOOTH BLEACHING

2. Contents:
Introduction
History
Bleaching agent
Classification of Bleaching technique.
Vital bleaching technique
Effect of vital bleaching on tooth structure
Effect of vital bleaching on tetracycline stain
Effect of vital bleaching on Fluorosis stain
Effect of vital bleaching on restorative material
Conclusion
References

3. • Tooth discoloration is a common problem leading patients to
seek esthetic treatment.
• The causes of tooth staining must be carefully assessed for
better prediction of the rate and the degree to which
bleaching will improve tooth color, since some stains are
more responsive to the process than others.
Jordan, R.E., Boksman, L.Contin. Educ. Dent.1984;5:803–807.

4. Tooth Discolorations
IntrinsicExtrinsic

5. Extrinsic stains
• Plaque, chromogenic bacteria, surface
protein denaturation
• Mouthwashes (e.g., chlorhexidine)
• Beverages (tea, coffee, redwine, cola)
• Foods (curry, cooking oils and fried foods,
foods with colorings, berries, beetroot)
• Antibiotics (erythromycin, amoxicillins
• Iron supplements

6. • These stains are localized mainly in the pellicle and are
either generated by the reaction between sugars and
amino acids or acquired from the retention of exogenous
chromophores in the pellicle.
• The reaction between sugars and amino acids is called the
‘‘Millard reaction’’ or the ‘‘non-enzymatic
browning reaction’’ and includes chemical
rearrangements and reactions between sugars and amino
acids.
Viscio, D.et al.Compend. Contin. Educ.Dent. Suppl. 2000. 28, S36–
S43, quiz S49.

7. Intrinsic
stains
Pre-eruptive
Disease:
• Hematologic diseases
• Diseases of enamel and dentin
Medication:
• Tetracycline stains
• Fluorosis stains
Post
eruptive
• Trauma intrapulpal hemorrhage pulp
necrosis
• Primary and secondary caries and
erosion, buccal and palatal .
• Dental restorative materials
endodontic materials.
• Aging

8. The lightening of color of the tooth through the application of a
chemical agent to oxidize the organic pigmentation in the tooth.
Bleaching — the use of a chemical agent, sometimes in
combination with heat, to remove tooth discolorations.
Extracoronal bleaching (external bleaching) — the use of a
chemical agent on the outside of a tooth to remove discoloration
from tooth structures; most frequently used agents are hydrogen
peroxide and urea (Carbamide) peroxide.
Bleaching:
AAE Glossary of Endodontic Terms 2012
Grossman 12th edi

9. • Vital teeth were also bleached as early as 1868, by means of
oxalic acid or Pyrozone and later with hydrogen peroxide.
• In Fisher1911, the use of concentrated hydrogen peroxide with
a heating instrument or a light source for tooth bleaching.
.
Alqahtani MQ et al. Saudi Dent J. 2014 Apr; 26(2): 33–46
History:

10. • Furthermore, in the late 1960s, a successful home-bleaching
technique was established when Dr. Bill Klusmier, an
orthodontist, instructed his patients to use an “over-the-
counter” oral antiseptic, which contained 10% carbamide
peroxide delivered via a custom-fitting mouth tray at night.
• Dr. Klusmier found that this treatment not only improved
gingival health but also whitened teeth.
.
Alqahtani MQ et al. Saudi Dent J. 2014 Apr; 26(2): 33–46

11. • Subsequently, Proxigel (a mixture of 10% carbamide peroxide,
water, glycerin, and carbopol) was marketed.
• Haywood and Heymann (1989) described a home-bleaching
technique in their article, “Nightguard vital bleaching”, and an
at-home bleaching product “White and Brite™” was
introduced.
.
Alqahtani MQ et al. Saudi Dent J. 2014 Apr; 26(2): 33–46

12. • The “over-the-counter” (OTC) bleaching agents were first
launched in the United States in the 1990s, containing lower
concentrations of hydrogen peroxide or carbamide peroxide
and sold directly to consumers for home use.
• Finally, the current in-office bleaching technique typically uses
different concentrations of hydrogen peroxide, between 15%
and 40%, with or without light and in the presence of rubber
dam isolation.
.
Alqahtani MQ et al. Saudi Dent J. 2014 Apr; 26(2): 33–46

13. Bleaching agents

14. Properties of the ideal whitening agent:
• Easy to apply to the teeth for maximum patient compliance.
• Be nonacidic (have a neutral pH).
• Lighten the teeth successfully and efficiently.
• Remain in contact with oral tissues for short periods.
• Have an adjustable peroxide concentration.
• Be nonirritating.
• Not dehydrate the oral tissues or teeth.
• Not cause damage to the teeth.

15. Hydrogen Peroxide:
It is clear, colorless, odorless liquid, stored in amber
colored bottles.
Various concentration of this agent are available but 30-
35% stabilized solution of H2O2(superoxol) are most
common.
It is stored in refrigerated container where it retains
sufficient potency for appro 3-4 months.

16. Carbamide Peroxide:
It is also known as urea hydrogen peroxide, carbamyl
peroxide,perhydrol urea (3-45%)
Carbamide peroxide (CH6N2O3) in a 10% gel
formulation is the most commonly used home whitening
material.
The material is normally supplied in a syringe for ease of
application, although some products are supplied in
blister packs.

17. CP breaks down to a 3.6% solution of hydrogen
peroxide (H2O2) and a 6.4% solution of urea
(CH4N2O).

18. • The 15% carbamide peroxide solution (CPS) yields
5.4% hydrogen peroxide, and the 20% solution yields
7% hydrogen peroxide.
• A 35% carbamide peroxide gel is available as Quickstart
(DenMat, Lompoc, CA) and 45% gel as Opalescence
Quick (Ultradent Products, South Jordan, UT).

19. UREA:
• Stabilize the hydrogen peroxide.
• Elevate the pH of the solution.
• Enhance other desirable qualities, such as
anticariogenic effects, saliva stimulation, and
wound healing properties

20. THICKENING AGENTS
Carbopol (carboxypolymethylene)
• Carbopol is a polyacrylic acid polymer and its
concentrations range from 0.5–1.5%.
• Slow release of oxygen
• enhances the viscosity of the whitening material.
• Its thixotropic nature allows better retention of the slow-
releasing gel in the tray and improves adherence to the
tooth.

21. VEHICLE:
GLYCERIN:
• Carbamide peroxide is formulated with a glycerin base,
which enhances the viscosity of the preparation and ease
of manipulation.

22. SURFACTANT AND PIGMENT DISPERSANTS:
• The surfactant functions as a surface wetting agent, which
allows the hydrogen peroxide to diffuse across the gel–
tooth boundary.
• Gels with surfactant or pigment dispersants may be more
effective than those without them

23. PRESERVATIVES
• Methyl, propyl paraben, and sodium benzoate are
commonly used as preservative substances.
• They have the ability to prevent bacterial growth in
whitening materials.
• Many of the gels contain a preservative such as citroxain,
phosphoric acids, citric acid, or sodium stannate.
• These preservatives sequestrate transitional metals such as
iron, copper, and magnesium, which accelerate the
breakdown of hydrogen peroxide

24. FLAVORING AGENT:
• Flavorings are used in whitening materials to improve
the taste of the material, add to the selection of
whitening agents, and improve acceptability of the
product to the patient (e.g., melon and mint).

25. Mechanism of action of bleaching agent
The bleaching process is based on oxidation of bleaching
material.
The oxidation-reduction reaction that takes place in
bleaching process is known as REDOX REACTION.
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.

26.  The H2O2 flow freely through the enamel and
dentin owing to the porosity and permeability of
these structures.
 The free movement is caused by the relatively
low molecular weight of the peroxide molecule
and the penetrating nature of the oxygen and
superoxide radicals.
 The free radicals are produced have unpaired
electron; they are unstable and hence will attack
most other organic molecule to achieve stability.

27. This results in reduction of absorption energy of organic
molecules in the tooth enamel, releasing the color thus
creating a successful whitening action.

28. Bleaching Techniques
Non-VitalVital

29. Vital
Bleaching Techniques
OTCIn office
Home /Night-
guard Bleaching

30. Nightguard Vital Bleaching

31. • Home whitening is a simple technique whereby, after
an initial consultation with the dentist, a mouthguard
or tray is made for the patient to whiten the teeth at
home.
Terminology:
1) Matrix bleaching.
2) Dentist-assisted or dentist-prescribed
home- applied whitening.
3) Dentist-supervised at-home whitening.
4) At-home whitening.

32. 1. It is simple and fast for
patients to use
2. It is cost-effective.
3. Patients can whiten their
teeth at their convenience,
according to their personal
schedule.
4. Patients can see the results
relatively quickly.
Advantages
1. The color change is
dependent on the amount of
time that the trays are worn.
2. The system may be open to
abuse by use of excessive
amounts of whitening agent
for too many hours per day .
3. It is difficult for patients
who gag easily to tolerate
the whitening trays in the
mouth.
Disadvantages

33. Indications
• Mild generalized staining
• Age-yellowing discoloration.
• Mild tetracycline staining.
• Very mild fluorosis (brown or white)
• Acquired superficial staining.
• Stains from smoking tobacco
• Absorptive and penetration stains (tea and coffee)
• Young patients with an inherited gray or yellow
hue to the teeth

34. Contraindications:
• Severe tetracycline staining, pitting hypoplasia,
fluorosis stain.
• Teeth with tooth surface loss from attrition,
abrasion, and severe erosion.
• Teeth exhibiting extreme sensitivity to heat, cold,
touch, and sweetness.
• Teeth with deep and surface cracks and fracture
lines.
• Teeth with pathology such as a periapical
radiolucency.

35. Procedures:
1. Initial Consultation
2. Clinical Examination Of All Teeth
3. Planning The Treatment
4. Impression Taking
5. Tray fabrication

36. • The advantages and disadvantages of tooth whitening.
• Any side effects that may be experienced (such as
sensitivity, gingival irritation.
• The risks and benefits of the procedures; the patient’s
informed consent should be obtained.
• The duration of treatment.
• Further esthetic treatment that may be needed.
Initial Consultation:

37. • A comprehensive examination should be performed to
assess the soft tissues, mucosae, teeth, gingivae, and oral
health status of the patient.
• Check the integrity of the existing restorations.
• Check recent radiographs for dental disease and periapical
radiolucencies.
• The size and vitality of the pulps of the teeth can be
assessed on radiographs to predict sensitivity levels.
Clinical Examination Of All Teeth

38. • Before treatment is begun, discuss
with the patient the possible shade
lightening that can be achieved.
• Shade taking can be done via the
normal methods—that is, using
the porcelain shade guide or the
shade guide supplied with the
whitening kit.
Preexisting Shade Evaluation

39. • It is normally advisable to whiten only one arch at a time
so that the patient has the opportunity for a comparison.
• Photographs with the shade tab that currently matches the
teeth are taken.
• It is also essential to discuss with patients that their
existing composite restorations may not match after
whitening and that it may be necessary to replace these
composites with lighter ones after the whitening
procedures.
Planning The Treatment:

40. • Excellent impressions reproducing the surfaces of the
upper and lower teeth should be taken so that whitening
trays can be made.
Impression Taking

41. • Be strong enough to avoid damage by the patient during wear.
• Be easy to fit and easy to remove after a treatment session.
• Be made from a material that is bioinert .
• Be thin enough to be well tolerated in the mouth.
• Be smooth and well polished so that there are no rough edges.
• Fit comfortably and passively and not feel too tight in places.
Tray making:

42. • Full vestibule upper or lower trays.
• Trays with reservoirs
• Trays with no reservoirs.
• Trays with or without windows.
Tray Design Features

43. The vacuum tray-forming
machine.
The separator is placed
directly onto plaster teeth.
The separator is air dried
onto the plaster teeth.
The plastic tray material.
Tray Fabrication:

44. Remove the tray from the
model
The model is placed into the
vacuum tray-forming machine.
Securing tightly onto the vacuum
tray-forming machine.
Allowing the heated material to
cool down.

45. The excess is removed . The fine trimming and the
scalloping
Final trimming of the tray on
the model.

46. The tray is smoothed
with a polishing wheel.
The trays are scalloped
lingually and buccally.
Completed tray positioned in the mouth.

47. Loading Tray and placement of tray:
A syringe loading
gel is placed
Seats the tray and compresses to ensure
that the gel is placed properly.
A blister pack
application.

49. Gingival irritation.
Patients may complain of painful gums after a few days of
wearing the trays.
 It is important to check that the tray is fitting correctly and
not impinging on the gingivae.
The trays may need to be adjusted, trimmed back, polished.

50. Soft tissue irritation.
Some patients develop soft tissue irritation, which may be
from overwearing the trays or applying too much
whitening agent to the trays.

51. Tooth thermal sensitivity.
This is the most common side effect and normally occurs
after about 2 or 3 days of wearing the trays.
Desensitizing toothpaste can be used 2 weeks before
whitening, by brushing the teeth with the desensitizing
toothpaste or into the whitening tray or directly onto the
sensitive parts of the teeth.

52. Tooth thermal sensitivity.
Neutral sodium fluoride gel can be used for desensitizing;
applied directly with a brush onto the teeth or it can be
placed into the whitening tray .
Proprietary agents containing potassium nitrate can be
applied directly into the tray.
 The tray can be worn overnight.

53. IN-OFFICE POWER BLEACHING:

54. Power bleaching or professional in-office bleaching is a
term used to describe the treatment of discolored dentition
with high-concentration oxidizing agents by the dentist
chairside.
Terminology:
 Chairside bleaching
 Laser bleaching
 Dentist assisted bleaching

55. 35% H2O2 liquid/gel
35% carbamide peroxide
Dual activated bleaching system
Materials available:

56. 1. It is simple and effective for
dentist to use .
2. The treatment is dentist
operated.
Advantages
1. Expensive
2. Bleaching agent used are
stronger and caustic in
concentration
Disadvantages

57. Power
Bleaching Techniques
Heated
instrument
Dual Activated
power bleaching
Compressive
power bleaching
Light sources
Warming the
bleaching agent

58. Miara (2000) suggested that power bleaching could be
more effective by compressing the bleaching material on
the tooth.
Use of 35% H2O2 is recommended
The benefit of this technique ; it influences penetration of
oxygen ions into tooth enamel.
Compressive power bleaching:

59. The Hi-lite in office bleaching system is formulated both
light and chemical activation.
It contains:
Ferrous sulphate:-chemical activator ,completes
procedure in 7-9 mins.
Manganese sulphate:- light activator,
fasten treatment 2-4 min
Dual Activated power bleaching:

60. Uses H2O2 in high concentration 19-35%
It has blue-green indicator dye which starts off blue and as
it becomes deactivated it is changes to white.
Dual Activated power bleaching:

61. Rubber dam isolation
Guaze soaked with 35% H2O2 liquid placed on tooth.
Heating instrument is applied for period of 1-3 mins to
enhance effect of bleaching.
Power bleaching using heat instrument:

62. The use of light to supplement the bleaching
process in dentistry was reported as early as 1918
(Abbot 1918).
Heat lamps (19th century–1980).
Early bleaching lamps made use of an incandescent
or photographic floodlight
This type of light source produced a continuous
spectrum with high infrared emission, which
supplied a source of indirect heat.
Power bleaching using Bleaching light:

63.  Rubber dam isolation
 Guaze soaked with 35% H2O2 liquid placed on tooth left on
tooth for 30 mins with light set 30 cm away from teeth.
 It is repeated at one/two week interval for 3-5 appointments.

64. • vital teeth, temperatures were recommended in a range of
46°C to 60°C (115°F to 140°F).
• For nonvital teeth temperatures as high as 71°C (160°F) were
recommended
• The risk of increasing the pulpal temperature beyond the
critical threshold of 5.5°C, at which irreversible pulpal damage
can occur, is a concern with any system that raises the
temperature of vital teeth.
.
• The use of heating lamps has fallen out of favor for vital teeth
and may be considered obsolete by today’s standards.
Zach and Cohen 1965, Baik et al. 2001

65. Halogen lamps (1980s–2000):
• The halogen gas causes evaporated
tungsten to redeposit on the
filament, improving the filament life
and allowing a higher color
temperature than the standard
incandescent lamp.

66. • Liang S et al. evaluate the effect of halogen light
irradiation on in-office bleaching, in terms of HP
concentrations, tooth whitening effects, colour stability,
and temperature variations in bleaching agents and pulp
chambers.
(1) In-office bleaching system, with or without light
irradiation, was effective for tooth whitening;
(2) The involvement of halogen light could enhance the
immediate whitening effect but have little influence on
the long-term whitening effect over the four-week
observation period.
Liang S et al. Australian Dental Journal 2012; 57: 1–7

67. High-intensity discharge (HID)
lamps (1990s–current).
• High-powered lamps that produce light by ionizing
noble gases (xenon, krypton) or metal halides between
two electrodes.

68. • HID lamps may properly be referred to as metal halide
lights and are often referred to as “plasma arc lights”
• These lamps are typically wide-spectrum lamps using
band pass filters to narrow the emission primarily to the
short ultraviolet to blue light (380–500 nm)

69. • Nakamura, et al. (2001) and Kashima-Tanaka, et
al. (2003) reported that the PAC significantly changed
the tooth color.
• whereas Hein, et al. (2003) and Lima, et al. (2009)
demonstrated that the PAC did not effectively activate
the bleaching gels
Nakamura T et al. J Oral Rehab. 2001;28:1080-4.
Kashima-Tanaka M, et al J Endod. 2003;29:141-3
Lima DA, et al J Prosthodont. 2009;18:249-54
Hein DK, et al. Compend Contin Educ Dent. 2003;24:340-52

70. Light-emitting diode (LED) lamps
(2000–current).
• Solid-state, semiconducting energy
sources that supply near-monochromatic
light.
• An led bleaching light system is
dependent less on heat and more on the
wavelength-specific photochemistry of
the bleaching formula and possible energy
absorption of the natural tooth
chromogens contributing to bleaching
effect

71. • Kossatz (2011) reported a larger difference in bleaching
with a light-emitting diode than without it (on 35% HP
gel), with a shade guide value.
• However, tooth sensitivity was higher for the LED
treated group after 24 hours of treatment.
Kossatz S, et al. Oper Dent. 2011 May-Jun; 36(3):251-7

72. • Yazici AR et al measured the temperature increase in the
pulp chamber of extracted teeth produced by the
Zoom!™
• Zoom!™ light either used with or without bleaching gel
did not show a significant increase in the intrapulpal
temperature of teeth when used for the recommended
exposure time.
Yazici AR, J Contemp Dent Pract 2007
May;(8)4:019-026

73. Rubber dam isolation
35% carbamide peroxide gel heated to 80°C and applied
directly onto tooth.
Power bleaching using heated bleaching
gel :

74. • In preparation for bleach application, tooth plaque or
superficial stain is removed using prophylaxis paste or
pumice of flour paste in a rubber polishing cup
Prophylaxis:

75. Initial Shade
• Document the pre bleaching shade using shade
guide.
Light-protective Glasses And Light Guides
• When using a supplemental light device, it is essential to
provide the patient with light-protective eyewear to filter
harmful radiation.
• It has been shown that many lamps exceed standards set
for eye exposure to direct blue light
Bruzell et al. 2009.

76. LIP PROTECTION AND CHEEK RETRACTION
A barrier cream or oil is applied to the lips before
insertion of the cheek and lip retractors

77. GINGIVAL ISOLATION
Resin barrier material is scalloped
from papilla to papilla.
Barrier seal is completed and ready
for bleach application.

78. ACTIVATION OF BLEACH, IF REQUIRED:
• A syringe-to-syringe mixing product will require the user to
attach the syringe with the bleaching agent to a second
syringe with the activator.

79. APPLICATION AND REAPPLICATION OF BLEACH
• The bleach material is applied to the
teeth in a layer 1–2 mm thick,
generally for 15–20 minutes per
application with three or four
applications per session.

80. APPLICATION AND REAPPLICATION OF BLEACH
• To avoid bleach splatter and dislodgement of
the barrier material, surgical suction is used to
remove the bleach between repeat applications
of fresh material.
REMOVAL OF BARRIER
• The resin barrier is ready for removal and
typically can be lifted in one piece by
grabbing hold of the attached cotton rolls or
dislodged using an explorer instrument

81. POSTBLEACHING SHADE
• The post-treatment shade is taken to document the color
change for the patient record and to demonstrate to the
patient the immediate outcome.

82. POST-BLEACHING INSTRUCTIONS:
• Post-bleaching instructions may include a
recommendation to wait a minimum of 6 hours after in-
office bleaching before drinking any chromogenic drinks
such as coffee or grape juice. (Ontiveros et al. 2008).
• To maintain the bleaching results, the patient can be
provided a custom at-home bleach tray for periodic
maintenance or for continued bleaching using the
combination technique.

83. • Hein et al., 2003 reported no difference in the whitening
effect of bleaching gels [25%-35% (HP)] with or without
three different lights (LumaArch, Optilux 500, and
Zoom!).
• They concluded that the chemicals added to the
bleaching gels acted as catalysts in the whitening process
and were solely responsible for activation, where as the
lights had no influence.
• Hahn et al., 2013could not find an improvement in tooth
whitening as a result of LED or laser light treatments,
when evaluating the colour stability of bleaching with
38% hydrogen peroxide using four different methods:
activation with halogen, LED, laser or chemical
activation

84. • Ferrarazi et al., concluded that LED lamps are effective,
safe and inexpensive to activate the hydrogen peroxide.
• Dominguez et al., 2011 reported that only the diode laser,
halogen lamp and LED lamp showed significant colour
changes on three different 35% hydrogen peroxide
whiteners.
• It was concluded that the light source is more important
than the bleaching agent in the whitening process.
• He et al., 2012 reported that a light-activated system
produced better immediate bleaching effects than a non-
light system with lower concentrations of hydrogen
peroxide.

85. Laser Bleaching technique:

86. The role of laser in teeth whitening is to accelerate the
activation of hydrogen peroxide (H2O2) in whitening gels
which typically contain 30% to 35% H2O2 concentration.
In reaction to the absorption of photon, the hydrogen
peroxide breaks down into particle of water and radical of
oxygen.

87. • The free radical oxygen chemically reduces larger
organic-pigmented molecules (the chromophores) in the
enamel matrix into smaller, less pigmented constituents
by rapid oxidation.
• These compounds that originally have double bonds and
long carbon chains are subsequently reduced to smaller
carbon chains and hydroxyl groups, which eliminate
discoloration.

88. Types of lasers:
• Carbon dioxide
• Argon (488nm)
• Neodymium:yttrium-aluminium-garnet
(Nd:YAG)
• Erbium-chromium:yttrium-scandium-
gallium-gamet (ErCr:YSGG)

89. 1. Faster due to higher
concentration of active
ingredient.
Advantages
1. Expensive
2. Time consuming
Disadvantages

90. Yarborough concept of bleaching:
According to the concept ,mixture of 50% H2O2 in
sodium perborate powder base.
Argon laser energy is used to remove deep colored stains
followed by CO2 laser that is absorbed rapidly by
bleaching paste.
The teeth are then cleaned, followed by final coating of
fluoride gel.

91. Mathews et al
(2014)
Compare the clinical
efficacy of an in-office
Bleaching system using a
810 nm diode laser and
conventional in-office
bleaching system.
Diode laser 810 nm has
proven effective.
Reza et al
(2017)
Compared the efficacy of
power bleaching and laser
bleaching technique and
diode laser as an activator
in their tooth whitening
capacity.
Both laser-assisted and
power bleaching
techniques were
capable of altering
tooth color change, but
laser bleaching was
deemed a more efficient
technique in this regard.

92. OTC technique:

93. Bleaching tooth paste and mouthwash:
OTC products are a low-cost alternative for
white discolored teeth without dentist
supervision.
These products generally contain lower levels
of a whitening agent and are self-applied to
teeth by means of gum shields, strips, paint-on
brushes, toothpastes, and mouthwash
products..
They commonly require two daily applications
for up to 2 weeks

94. • Trayless bleaching system.
• Delivery system is a thin strip precoated with adhesive 5.3%
H2O2 gel
H2O2 strips:

95. • The backing is peeled off and the strip
placed directly to the facial/buccal surfaces.
• Each strip is worn for 30 minutes, removed
and discarded and procedure takes place
twice a day for 14 days.

96. ListerineWhitening
mouthwash
Water, alcohol (8%), hydrogen peroxide,
tetrapotassium pyrophosphate, pentasodium
triphosphate, citric acid, poloxamer 407, flavor,
sodium saccharin, and sucralose
Opalescence PF 10% Glycerin, water, xylitol, carbamide peroxide,
flavor, carbomer, PEG-300, sodium hydroxide,
potassium nitrate, EDTA, and sodium fluoride
Crest 3DWhite Multi-
Care
whitening mouthwash
Water, 1.5% hydrogen peroxide, propylene
glycol, sodium hexametaphosphate, poloxamer
407, sodium citrate, flavor, sodium saccharin, and
citric acid
Details of mouthwashes products and bleaching gel

97. N. Sharif etal
(2000)
Measured the chemical
stain removal properties
of a range of whitening
toothpaste products
Only a small number of
the whitening toothpaste
products have good
chemical stain removal
potential.
Karadas etal
(2015)
Analyze the efficacy of
mouthwashes containing
hydrogen peroxide
compared with 10%
carbamide
Peroxide (CP) gel
The color change
achieved with the
mouthwashes was
significantly lower than
that achieved with the
10%
CP at-home bleaching
gel.

98. Effect of bleaching on tooth
structures:

99. Effects On Enamel:
Smidt et al. (2011), evaluated the morphologic,
mechanical, and chemical effects of 16%, 15% carbamide
peroxide bleaching agents on human enamel in situ and
they found that enamel surfaces showed no mechanical,
morphologic, or chemical changes after bleaching.
Smidt et al. (2011), Quintessence Int. 2011;42:407–412

100. • Cadenaro et al. (2010) conducted an in vivo study to
test the effect of a hydrogen peroxide in-office whitening
agent on enamel and demonstrated that the application of
a 38% hydrogen peroxide in-office whitening agent did
not change enamel surface roughness, even after multiple
applications.
Cadenaro et al. (2010) J. Am. Dent. Assoc. 2010;141:449–454.

101. • Efeoglu et al. (2005) used micro-computerized
tomography to evaluate the effect of 10% carbamide
peroxide applied to enamel.
• Results indicated that the cause demineralization of the
enamel extending to a depth of 50 μm below the enamel
surface.
• Therefore, they recommended that the application of
bleaching agents should be carefully considered in
patients susceptible to caries and tooth wear.
Efeoglu N. et al. J. Dent. 2005;33:561–567

102. • Azrak et al. (2010) conducted an in vitro study to assess
the effects of bleaching agents on eroded and sound
enamel specimens and concluded that bleaching agents
with a high concentration of peroxide or an acidic pH can
provoke surface roughness of sound or eroded enamel.
Azrak et al. J. Esthet. Restor. Dent. 2010;22:391–399.

103. Effects On Dentin:
• Pecora et al. (1994) found that dentin microhardness
decreased after the application of a 10% carbamide peroxide
agent for 72 h.
• Basting et al. (2003), results showed that the thickening
agent (carbopol and/or glycerin), not just the 10% carbamide
peroxide, caused a decrease in dentin microhardness.
• Tam et al. (2005) concluded that direct exposure to 10%
carbamide peroxide caused a significant decrease in the
flexural strength and flexural modulus of bovine dentin.
Tam L.E.et al J. Dent. 2005;33:451–458.
Basting R.T.et al. J. Am. Dent.
Assoc. 2003;134:1335–1342.
Pecora J.D.,et al Braz. Dent. J. 1994;5:129–
134.

104. Effects On Dentin:
• Lewinstein et al. (1994) showed a decrease in the
microhardness of dentin following exposure to a 30%
solution of hydrogen peroxide at pH 3.
• Tam et al. (2007) found that in vitro fracture resistance of
dentin was reduced after the prolonged use of bleaching
products applied directly to dentin.
Lewinstein I. et al J. Endod. 1994;20:61–63.
Tam L.E. et al J. Esthet. Restor.
Dent. 2007;19:100–109. discussion 110

105. Effects On Pulp:
• Pulp penetration can occur within 5–15 minutes
according to studies by Cooper et al. (1992).
• Application of peroxide gel resulted in rapid
penetration of peroxide to the pulp chamber.
• Minor irritation of the pulp tissue may occur, but it
resolves within 2 weeks after cessation of treatment.

106. • Camargo,SEA et al evaluated the pulp chamber penetration
of peroxide bleaching agent in human and bovine teeth after
office bleach technique.
• Independent of the presence of restoration, all teeth
submitted to bleaching presented peroxide penetration into
the pulp chamber
• The human teeth presented higher peroxide penetration
than the bovine teeth
• Peroxide penetration into the pulp chamber of restored
teeth depends on the type of restorative material; it is
higher in teeth restored with resin-modified glass ionomer
cement.
Camargo,SEA et al J Endod 2007;33:1074–1077)

107. • Patri G et al investigate the pulp chamber penetration of
bleaching agent in intact teeth and teeth following
restorative procedure.
• They concluded that peroxide readily penetrates into the
pulp through intact and restored teeth, with restored teeth
showing higher pulpal peroxide levels than intact teeth.
• Teeth restored with resin modified glass ionomer cement
showed higher pulpal peroxide level than teeth restored
with composite resins
Patri G et al J Clin Diagn Res 2013 Dec; 7(12): 3057–3059

108. Tetracycline-stained Teeth
When bleaching tetracycline-stained teeth, Haywood,
Leonard and Dickinson,1997, were the first to show that
using carbamide peroxide (CP) applied in trays and used
overnight can be effective.

109. Two approaches have been used to treat tetracycline
discoloration:
(i) bleaching the external enamel surface
(ii)Intracoronal bleaching following intentional root
canal therapy.
Kinoshita et al
(2009)
KTP laser, a type
of Nd:YAG laser,
for bleaching of
tetracycline stained
teeth.
Effective
Shorter time
Simple chemical
technique.
No damage to the
vital pulp and hard
tissue crystals

110. Kwon et al (2012) Described the use
of an extended
whitening
treatment of 2nd
degree
tetracycline stained
teeth.
Combination
of in-office and
home whitening
provided a fast
whitening result.
Whitening of the upper arch for
8 weeks produced marked
difference between the upper
and lower teeth
Post-treatment photograph,
after a combination of in-
office and home whitening
for 16 weeks

111. Fluorosis and bleaching technique:
Dental fluorosis, which is a hypomineralization of enamel
due to the effects of excessive fluoride intake, results in
white opaque areas or discolorations ranging from yellow
to dark brown together with surface porosities on the
enamel surface.
Fluorosis staining is commonly considered an esthetic
problem because of the psychological impact of unesthetic
maxillary or mandibular anterior teeth

112. Guillen et
al (2003)
Used nightguard
vital bleaching
technique using
carbamide and
hydrogen peroxide as
active agents
Carbamide peroxide at
10 and 20% and
hydrogen peroxide at
7.5% showed good
clinical effectiveness
in improving clinical
appearence, but it is
important to point out
that clinical success is
only in cases of class 1
to 3

113. Yildiz
et al
(2013)
Described minimally
invasive technique
including enamel
microabrasion followed
by in-office bleaching
The minimally invasive
technique including enamel
microabrasion and in-office
bleaching was efficient
After enamel
microabrasion.
Teeth after in-
office bleaching.
Severe Fluorosis
tooth.

114. Effect of bleaching on restorative
materials:

115. Restorative Material And Bleaching Agents:
Amalgam
Dental alloy
Dental ceramic
Glass ionomer cement
Composite resin
Effect of bleaching agents on bond strength of restorative
materials to tooth structure .

116. Amalgam:
Al-Salehi et al 2006 found no significant change in the
release of metal ions from bleached amalgam (10% CP for
24 hours)
Kasraei S et al 2010 reported a significant increase in the
release of amalgam components (mercury and silver) after
being exposed to CP (10-16%) and HP (3.6%, 6%, and 30%)
for a longer treatment period.

117. Amalgam:
El-Murr J et al 2011 reported that the concentration of
mercury leaching from amalgam is below a level associated
with possible health concerns.
Schemehorn B et al reported that the greening of the tooth
amalgam margin during extended 10% CP bleaching (7-10
months)

118. Dental alloy:
Duschner H et al 2004 observed no significant deleterious
effects of HP bleaching on gold alloy surfaces on surface
microhardness .
Tamam E et al in 2011 reported, Surface topographic
alterations of gold, Ni-Cr, and Co-Cr alloys as a result of the
application of 10% and 35% CP simulating at-home
bleaching and in-office bleaching during 14 days,
respectively.

119. Dental alloy:
The HP bleaching agents (3%, 10%, and30%) caused
increased corrosion potential of Ni-Cr and Pd-Cu-Ga alloys.
Al-Salehi SK et al J Oral Rehabil 2008;35: 276e82.

120. Dental ceramic:
Feldspathic porcelain exhibited surface deterioration in
contact with 10% and 35% CP for 21 days.
35% CP induced a reduction in surface microhardness of
both leucite reinforced and conventional glass ceramic.
The increased roughness and whiteness of leached ceramic
were possibly due to the reduction of surface SiO2 content.
..
Moraes RR et al Clin Oral Investig 2006;10:23e8
Tu¨rker SB J Prosthet Dent 2003;89:466e73
Malkondu O¨Oper Dent 2011;36:177e86

121. Composite resin:
10% CP application for 3 weeks was able to change the
surface roughness of packable composite resin.
But the surface microhardness remained unchanged.
Significant color changes of composite resin were observed,
the possible explanation of bleaching-induced color changes
of composite resin could be surface alteration and oxidation
of the pigment.
..
Basting R et al Esthet Restor Dent 2005;17:
Torres CR et al Oper Dent 2012;37:526e31

122. • SEM studies and profilometric analyses, it was shown
that 10–16% carbamide peroxide bleaching gels may
lead to a slight, but statistically significant, increase in
surface roughness and numbers of porosities of
microfilled and hybrid composite resins
Türker S.B.et al. J. Prosthet.
Dent. 2003;89:466–473

123. • Hannig et al. (2007) reported a significant decrease in the
surface hardness of bleached composite resins, not only on
superficial surfaces, but also in the deeper layers of the
filling materials.
• These results were related to the high oxidation and
degradation of the resinous matrix in the composites.
Hannig C. et al Dent. Mater. 2007;23:198–203
Taher N.M.. J. Contemp. Dent.
Pract. 2005;6:18–26

124. • Li et al. (2009) found significant changes in the color of
nanohybrid and packable composite resins after bleaching
with 15% carbamide peroxide.
Li Q. et al J. Dent. 2009;37:348–356.
• Generally, alterations in the color of restorative materials
have been attributed to oxidation of surface pigments and
amine compounds, which have also been indicated as
responsible for color instability of restorative materials
over time.
Inokoshi S.et al. Oper. Dent. 1996;21:73–80.

125. • Differences in color change between and among different
materials might be a result of different amounts of resin
and different degrees of conversion of the resin matrix.
• For the above-mentioned reasons, more color change was
found in chemically cured than in light-cured composites,
and this difference can be mainly attributed to the
composition of the matrix phase, especially the activator
system
Inokoshi S.et al. Oper. Dent. 1996;21:73–80.

126. The effects of pre-operative dental bleaching on the bonding
potential of composite resin restorations to tooth structure
Dishman M.V et al reported decrease in bond strength to the
presence of residual peroxide on the tooth surface, which
interferes with the resin bonding and prevents its complete
polymerization
Perdigão J et al. reported that vital bleaching will alter the
protein and mineral content of the superficial layers of
enamel, which may be responsible for reduced bond strength
Dishman M.V et al. Dent. Mater. 1994;10:33–
36
Perdigão J. et al. Am. J. Dent. 1998;11:291–
301.

127. • The SEM evaluation of bleached specimens, large areas of
enamel surface were resin-free and tags were poorly
defined and fragmented and penetrated to a lesser depth
when compared with those in the unbleached control
groups.
• In another study, SEM examination of resin and bleached
enamel interfaces displayed a porous and granular view
with a ‘bubbly’ appearance
Titley K.C. et al. J. Dent. Res. 1992;71:20–24.
Titley K.C et al. J. Endod. 1991;17:72–75

128. • To improve the bond strength of previously bleached
teeth, different methods have been proposed in the
literature.
• The effectiveness of 10% sodium ascorbate in reversing
the compromised bond strength of enamel previously
bleached with 10% carbamide peroxide when bonded to
resin composite
• Lai et al. (2002) found that surface treatment with an
antioxidant (sodium ascorbate) can immediately reverse
the compromised bond strength of teeth bleached with
hydrogen peroxide or teeth treated with sodium
hypochlorite
Lai S.C et al. J. Dent. Res. 2002;81:477–481.

129. The effects of post-operative dental bleaching on the bonding
potential of composite resin restorations to tooth structure
The oxygen radicals released from peroxide bleaching
materials are known for their high reactivity and nonspecific
nature and may have side-effects on tooth tissues, restorative
materials and the bond between them, which is usually the
most susceptible to degradation.
Barcellos et al. (2010) evaluated the effect of bleaching gel
containing 10%, 15%, and 20% carbamide peroxide on the
bond strength of dental enamel or dentin and resin composite
restorations.
Barcellos D.C.,et al Oper. Dent. 2010;35:463–469

130. • Results showed that carbamide peroxide bleaching
agents could significantly affect the micro-tensile bond
strength (μTBS) between the restoration and dental
structure
Barcellos D.C.,et al Oper. Dent. 2010;35:463–469
• Dudek et al. (2012) investigated the effect of peroxide
bleaching gel on the durability of the adhesive bond among
composite material, enamel, and dentin created with the
etch-and-rinse adhesive
Dudek M. et al. Oper. Dent. 2012;33:394–407.

131. • They concluded that the durability of adhesive
restorations can be detrimentally influenced by carbamide
peroxide bleaching, and that different adhesives show
various levels of sensitivity to the bleaching gel.
Dudek M. et al. Oper. Dent. 2012;33:394–407.

132. Conclusion:
The increasing demand for tooth bleaching has driven many
manufacturers and researchers to develop bleaching
products to be used either in the dental office or at home.
However, as with any dental procedure, bleaching involves
risks.
To minimize the risks, the involvement of dental
professionals, the prevention of using of OTC bleaching
products and the reduction of overused of bleaching products
are necessary.

133. Conclusion:
The dentist must understand the differences amongst the
currently available bleaching techniques and the difference in
concentration of various products.

134. Thank you

135. References:

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