CONSERVATIVE AND ENDODONTICS

1. PRESENTED BY:
SAPAM SONIA
ROLL NO :15
BDS FINAL YEAR

2. CONTENTS
PART A
 INTRODUCTION
 CLASSIFICATION OF TOOTH DISCOLORATION
 CAUSES AND COLOR
 BLEACHING
Definition
Bleaching agents
Indications and Contraindications
Mechanism of bleaching
Factors affecting bleaching
 REFERENCE

3. Introduction
 Esthetics is an important factor in a patient’s decision to
undergo endodontic treatment. A frequent question is,
”Will my tooth turn black?? The usual response is a
“qualified no,” with the explanation that modern
treatment and procedures are design to avoid crown
staining and tooth discoloration.
 Nevertheless, teeth may undergo discoloration,
sometimes before endodontic treatment, sometimes
afterward, in spite of all the precautions taken to prevent
the colour changes in the tooth. Hence, when such teeth
discolour, bleaching should be considered as a means of
restoring tooth esthetics.

4. CLASSIFICATION OF TOOTH DISCOLORATION
Tooth discoloration can be classified as:
1)Extrinsic Discoloration
2)Intrinsic Discoloration
1)EXTRINSIC DISCOLORATIONS
Extrinsic discolorations are found on the outer surface of teeth
and are usually of local origin, such as tobacco stains.
Common causes:
a)The green discoloration associated with the Nasmyth’s
membrane in children.
b)Tea and tobacco-stains
c) Silver nitrate stains
d) Food stains

5.  Nathoo’s Classification of Extrinsic Discoloration
Newer classification based on chemistry of staining was
put forth by Nathoo in 1997
1)N1 type or direct dental stain:
a)The colored materials(chromogens)bind to the tooth
surface and cause discoloration.
b)The color of the dental stain is same as the color of the
chromogen.
2)N2 type or direct dental stain:
a)The chromogen changes color after binding to the
tooth.
3)N3 type or indirect dental stain:
a)Colorless material or a prechromogen binds to the
tooth and undergoes chemical reaction to cause a stain.
.

6.  Scaling and polishing during tooth prophylaxis
can remove these type of stains expect the
silver nitrate stains which are impossible to
eliminate without grinding because the stains
penetrate the surface of the crowns and are
difficult to remove by chemical means alone.

7. 2)INTRINSIC DISCOLORATIONS
 Intrinsic discolorations are due to the presence of
chromogenic material within the enamel or dentin
,incorporated either during odontogenesis or after
tooth eruption.
 If they incorporated into the dentin ,they become
visible because of the translucency of the enamel.
 Common Causes:
a)They can be related to periods of tooth
development,as in dentigerous imperfecta and
amelogenesis imperfecta .

8. b)Hematological disorders such as:
 Erythroblastosis fetalis
 Thalassemia
 Sickle cell anaemia
c)Decomposition of pulp tissue:
 It is probably the most common cause of tooth
discoloration,particularly if the pulp is necrotic.
 After the death of the pulp or treatment of the tooth,
because of the slow formation of color producing
compounds.
d)Trauma:
 Causes rupture of blood vessel in the pulp.Causing
diffusion of blood into dentinal tubules.
 Dark pink immediate after trauma and changes to
pinkish brown after some days..

9. Causes:Hemoglobin degrades into
hemin,hematin,hematoidin,hematoporphyrin,and
hemosiderin.
Hydrogen sulphide produced by bacteria combines
with hemoglobin and gives dark color to tooth.
e)Calcific metamorphosis:
It is a condition characterised by rapid deposition of
hard tissue within the root canal.
In traumatic injuries, there is transient distruption of
blood supply causing destruction of odontoblasts.
These are repalced by cells of the undifferentiated
mesenchyme that lay down tertiary dentin.As a
result, tooth becomes more opaque due to the loss of
translucency.

10. f)Filling materials :
Silver amalgam produces a stain ranging from slate
gray to dark gray.
Copper amalgam-bluish black to black stain .
Stains from amalgam are likely to occur when the
dentinal wall is thin, and the filling material almost
shimmers through the enamel.
g)Endodontic materials(root canal medicaments):
 Essential oils from resinous substance discolor the
tooth structure.
h)Aging:
Physiological deposition of secondary dentin affects
the light transmitting properties of tooth,resulting in
the more opaque hue of the tooth color.

11. i)Iatrogenic discolorations:
Tooth discolorations caused by certain dental
materials or inappropiate operating techniques do
occur; such dentist- related discolorations are
usually preventable and efforts should be made to
avoid them.
j)Tetracycline stains(due to the interaction of
antibiotics with hydroxy apatite crystal during
mineralisation phase)
It can be classified into four groups according to the
severity:
 1st degree:Light yellow ,light brown or light gray
and occurs uniformly throughout the crown,
without the banding.

12.  2nd degree: Discoloration is more intense and also
without banding.
 3rd degree:Discoloration is very intense, and the
clinical crown exhibits horizontal color banding.
 4th degree : Does not respond to bleaching.
k)Endemic fluorosis:
 It is the most common pre-eruptive staining ,
which is caused by excessive fluoride ingestion
during tooth develoment causing hypoplasia.
 Discolaration is usually bilateral ,affecting
multiple tooth in both arches.It presents as various
degrees of intermittent white spotting, chalky or
opaque areas, yellow or brown discoloration, and
in severe cases ,surface pitting of the enamel.

13. Tetracycline stains

15. Tooth discoloration: Causes and Colors(Abbott,1997)
CAUSES
EXTRINSIC
Cigarettes,pipes,cigars,chewin
g tobacco,marijuana
Coffee,tea,foods
Poor oral hygiene
COLOR
Yellow brown to black
Brown to black
Yellow to Brown shades
EXTRINSIC AND INTRINSIC
Fluorosis
Aging
White ,yellow ,brown, gray,
black

16. INTRINSIC
Genetic conditions
Amelogenesis imperfecta
Dentinogenesis
imperfecta
Systemic conditions
Jaundice
Porphyria
Medications during tooth
development
Tetracycline
Fluoride
Brown,black
Brown,blue
Blue,green,brown and
purple-brown
Brown,grey,black

17. Body by-products
Bilirubin
Hemoglobin
Pulp changes
Pulp canal obliteration
Pulp necrosis
With hemorrhage
Without hemorrhage
Blue,green,brown
Grey and black
Yellow
Gray,black
Yellow,gray-brown

18. IATROGENIC CAUSES
Trauma during pulp
extirpation
Tissue remnants in pulp
chamber
Restorative dental materials
Endodontic materials
Gray,black
Brown,gray,black
Brown,grey,black
Gray, black

19. a.Amelogenesis Imperfecta
b.Dentinogenesis Imperfecta

20. AGE RELATED YELLOWING OF TEETH

21. TOOTH DISCOLORATION FOLLOWING DENTAL
TRAUMA AND DECOMPOSITION OF PULP
TISSUE

22. PINK DISCOLORATION FOLLOWING TRAUMA

23. ENDEMIC FLUOROSIS

26. INTRINSIC DISCOLORATIONS

27. EXTRINSIC DISCOLORATIONS

29. BLEACHING
 Bleaching may be defined as the lightening of the
color of the tooth through the application of a
chemical agent to oxidize the organic pigmentation in
the tooth.

30. BLEACHING AGENTS
 The goal of bleaching procedures is the restoration of
normal color to the tooth by decolorizing the stain
with a powerful oxidizing agent known as bleaching
agent.
 The most commonly employed bleaching agents are
as follows:
A. Hydrogen peroxide
B. Sodium perborate
C. Carbamide peroxide
D. Over-the-counter(OTC) agents

31. 1. HYDROGEN PEROXIDE
a. Various concentrations of this agent are available,
but 30-35% stabilized aqueous(Superoxol
Perhydrol) solutions are the most common.
Properties:
 It is a clear, colorless, odorless liquid, stored in
lightproof amber bottles.
 It is unstable and should be kept away from heat,
which could cause it to explode.
 It should be stored in sealed refrigerated containers
where it retains sufficient potency for
approximately 3-4 months .

32.  Care should be taken while handling hydrogen
peroxide because its ischemic effect on skin and
mucous membrane causes a chemical burn.
 As the amount needed for a bleaching operation is
about 1-2ml, the solution is dispensed into a clean
dappen dish.

33. 2. SODIUM PERBORATE
It is a stable, white powder, normally supplied in a
granular form that has to be ground into a powder
before using.
TYPES:
3 forms of sodium perborate which vary in their
oxygen content:
 Sodium perborate monohydrate
 Sodium perborate trihydrate
 Sodium perborate tetrahydrate

34.  Mechanism of action
 The powder is water soluble . When mixed into a
paste with superoxol, this paste decomposes into
sodium metaborate, water and oxygen.
Sodium perborate Sodium metaborate+
Hydrogen peroxide+ Oxygen

35. 3.CARBAMITE PEROXIDE
It is also known as urea hydrogen peroxide.
Its concentration ranges from 3-45% depending on
at-home and in-office bleach.
10% carbamide peroxide is the most popular
commercial preparations .
MECHANISM OF ACTION
Carbamide peroxide Urea + Ammonia +
Carbon dioxide+ 3.5% hydrogen peroxide

36. 4. OVER-THE COUNTER(OTC) BLEACHING
AGENTS:
These includes :
Tray systems
Trayless systems
Chewing gums
Toothpastes
Bleaching strips and
Paint- on products
These products primarily work by removing extrinsic
surface stain only.

39. MECHANISM OF BLEACHING
 The principle mechanism involved in bleaching is that
the oxidising agent reaches the sites within enamel and
dentin to allow a chemical reaction to occur between the
discoloured segment and the active ingredients.
 Hydrogen peroxide has a low molecular weight that
enables it to diffuse to the enamel matrix .
 Bleaching agents opens the more highly pigmented
carbon ring (yellow color)and convert it to carbon
chains.
 When the carbon double bonds are converted to
hydroxyl groups, the amount of light absorbed is
reduced.
 Hence,the tooth appears lighter in color.

40. • Saturation point is that point at which only
hydrophillic colorless tooth structure exists.Beyond
this point it results in the breakdown of the organic
matrix resulting in weakening of the enamel and
surface porosities.

41. MECHANISM OF BLEACHING
Larger stain molecules are converted into smaller ones
Free reactive radicals react with the unsaturated bones
REDOX REACTION
TOOTH(reducing agent
takes up electron)
BLEACHING(oxidising agent
gives free electron)

42. Reflects less light and becomes colorless
Simpler molecules are formed

43. FACTORS AFFECTING BLEACHING
1.Surface cleanliness:
a. Clean surface enamel is important to distinguish
between intrinsic and extrinsic stains.
b. Debris on the surface minimizes the contact of the
bleaching agent with the tooth surface
2.Concentration of peroxide
a. The effect of bleaching increase with the increase in
concentration of peroxide.
3.Shelf life
a. Carbamide peroxide is more stable than hydrogen
peroxide and has a shelf life of 1-2 years.

44. 4.Temperature
Increase the temperature accelerates the release of
oxygen free radicals
The reaction gets doubled with an increased of 10
degree celsius. However, an increase in the
temperature to an uncomfortable level causes tooth
sensitivity and irreversible pulpal damage.
Local anesthesia should be administered during
bleaching.
5.pH
Hydrogen peroxide is active in alkaline pH
Optimum pH for hydrogen peroxide ranges from
9.5-10.8

45. 6.Time
 Concentration of agent and the time of contact with the
tooth are the most important factors in effective
bleaching.
 Increased contact time increases the bleaching efficacy.
7.Sealed environment
 Hydrogen peroxide sealed in the access cavity maintains
the required concentration for active bleaching.
8.Additives
 In order to increase the viscosity of bleaching materials
,additives like glycerin, gylcol, and toothpaste -like
materials are added.
9.Other factors: Age of the patient, initial color of the tooth,
and gender also plays a role in bleaching process .

47. REFERENCES
TEXTBOOK OF ENDODONTICS-5th Edition
Ingle Bakland
Grossman’s ENDODONTIC PRACTICE-13rd Edition
B.Suresh Chandra V.Gopikrishna

48. THANK YOU