finish lines in fixed partial denture .pptx

finish lines in fixed partial denture .pptx

2. » Introduction
* Definition

* Principles of tooth
preparation

* Finish lines for
Extracoronal
restorations

OFull veneer crown
> Complete cast crown
> Metal - ceramic crown
> All-ceramic crown
— Porcelain veneer crown

Partial veneer crown
Onlays
¢ Finish lines for
Intracoronal restorations
O Inlays
OAmalgam
ODirect filling gold
UComposites
QGlass ionomer cement

+ Conclusion

3. Introduction

* One of the basic tenets of restorative dentistry is to conserve
as much tooth structure as possible consistent with the
mechanical and esthetic principles of tooth preparation.

Contemporary Fixed Prosthodontics 3" edition

4. Introduction.

* Restoration can survive in the biologic environment of
the oral cavity only if the margins are closely adapted to
the finish line of the preparation

= = Q
| |

Contemporary Fixed Prosthodontics 3" edition

5. Definition |

QAccording to Schwartz

* Refers to the border of the preparation where the prepared
tooth structure meets the unprepared surface of the tooth.

OAccording to Rosenstiel

A line of demarcation
The peripheral extension of a tooth preparation
The planned junction of different materials

Pepe

The terminal portion of the prepared tooth.

6. Principles of tooth preparation

Vom = D ee

Preservation of tooth structure

Retention and resistance

Structural durability — Marginal geometry

Marginal integrity — Marginal adaptation
Preservation of the periodontium — Margin placement

Herbert T. Shillingburg 3” edition

7. Preservation of tooth structure

« Avoide excessive destruction

+ Design restoration to reinforce and protect remaining
enamel and dentin -

Herbert T. Shillingburg 3% edition

8. Retention & Resistance

* Retention prevents removal of the restoration along
the path of insertion or long axis .

* Resistance prevents dislodgement of the restoration
by an apical/oblique forces

Herbert T. Shillingburg 3% edition

9. Retention (g/mm?
g 8

Herbert T. Shillingburg 3” edition

10. Substitution of internal feature

11. Structural durability |

* Adequate space created by tooth preparation

Occlusal reduction Axial reduction

12. Marginal integrity |

* Margins of restoration must be closely adapted to finish line
of preparation

* Configuration of the preparation finish line dictates the shape
of restorative material in the margin of the restoration

Herbert T. Shillingburg 3% edition

13. Finish line in extracoronal restoration

| Chamfer

Heavy chamfer

E

Shoulder

Sloping shoulder

E E
Knife edge/ Feather edge

Chisel edge

14
Contemporary Fixed Prosthodontics 3% edition

14. Extracoronal restorations - Finish line configurations

+ Finish line classification according to width

OMarginal width less than 0.3mm - Knife-edge/ feather edge
QO Marginal width upto 0.3mm — Chamfer

(Marginal width greater than 0.3mm - Shoulder

A.J. Hunter JPD 1990:64

15. ° GPT- A Finish line design for tooth preparation in
which the gingival aspect meets the external axial
surface at an obtuse angle.

+ TYLMANN (1965): Concave extra coronal finish
line that provides greater angulation than a knife-edge
and less width than a shoulder.

16. Advantage Disadvantage Indication

*Distinct margin «Care needed to avoid | «Cast metal

*Adequate bulk unsupported lip of restoration
*Easier control enamel Lingual margin of
metal ceramic

Round end taper Round end taper

17. Heavy chamfer |

Q Provides 90 degrees cavosurface angle with a large
radius rounded internal angle.

Q A bevel can be added to the heavy chamfer for use with
metal restoation.

Herbert T. Shillingburg 3" edition

18. Advantage Disadvantage

*Better support fora *Unskilled operator *Ceramic crown
ceramic crown can create an «With bevel metal
undesirable fragile crown
“lip” of enamel at
cavosurface

Round end taper

19. | Shoulder |

Q Finish line of choice for all-ceramic crown
Q Wide ledge provides resistance to occlusal forces

Q Produce the space for healthy restoration contours and
maximum esthtetic

Herbert T. Shilli

20. “Advantage *Disadvantage

*Bulk of restorative *Less conservative of +Facial magin of
material tooth structure metal ceramic crowns

«Stress concentration *Complete ceramic
at 90 degree internal crown

angle of the finish

line, hence conducive

to coronal fracture

Bur

Flat end taper

21. Radial shoulder |

Q Modification of shoulder finish line
Q Support for ceramic restoration is good

«Advantage *Disadvantage Indication
«Stress concentration ‘Less conservative of +Facial magin of metal
lesser than the classic tooth structure ceramic crowns
shoulder *Complete ceramic

crown

Herbert T. Shillingburg 3% edition

22. Flat end taper

End cutting carbide
finishing bur

Modified bine-angle
chisel

23. >

Shoulder with bevel |

«Bulk of material «Less conservative, *Facial magin of
extend peraparation posterior metal
apically ceramic crowns with

supragingival margin
+ Uses —

+ Gingival finish line on the proximal box of inlays and onlays
* Occlusal shoulder of onlays and mandibular three-quarter crowns
+ Finish line for extremely short walls

* More destruction of tooth - NOT USED routinely for full veneer
restorations

Herbert T. Shillingburg 3% edition

24. Sloping shoulder

DA 120-degree sloped shoulder margin used as an alternative to the
90-degree shoulder for the facial margin of a metal-ceramic crown.

O Reduces the possibility of leaving unsupported enamel

O Provides sufficient bulk to allow thinning of the metal framework
to a knife-edge for acceptable esthetics.

«Advantage *Disadvantage

«Bulk of material *Less conservative of *Facial magin of metal
tooth sturcture ceramic crowns

Contemporary Fixed Prosthodontics 3% edition

25. | Knife edge/ Feather edge

"= The ultimate finish line that permit an acute margin
of metal
=" Uses —
+ Lingual surface of mandibular posteroior teeth
* Very convex axial surfaces
* Surface towards which tooth is tilted
= Disadvantage —
+ Axial reduction may fade out
+ Thin margins difficult to wax and cast
+ Overcontoured restorations

Herbert T. Shillingburg 3% edition

26. Chisel edge |

* A variation of the featheredge,
+ Formed when there is a larger angle between
the axial surfaces and the unprepared tooth

structure.
* Associated with an excessively tapered
preparation

Contemporary Fixed Prosthodontics 3” edition

27. Fig. S-21. Types of finish lines. 1, Chamfer provides bulk at the
finish line. 2, Knite-edge provides minimal reduction. 3, Shoulder
used for porcelain jacket crowns. 4, Chamfer or shoulder with
bevel used for porcelain fused-to-metal crown. (Courtesy D.A.
Kaiser, San Antonio, Tex.)

A B c D E F G

A. Featheredge, B. Chisel, C. Chamfer, D. Bevel, E. Shoulder, F. Sloped Shoulder, G. Beveled
shoulder Contemporary Fixed Prosthodontics 3” edition

28. The Effect of Various Finish Line
Configurations on the Marginal Seal
and Occlusal Discrepancy of Cast Full
Crowns After Cementation - An In-vitro
Study

* Shoulder margins provide good seat but a
comparatively wider marginal seal

* Chamfer, long chamfer and feather edge margin

provide superior sealing of the margins despite poor
seat.

Journal of Clinical and Diagnostic Research. 2015 Aug, Vol-9(8 )

29. * Both ZZ and E copings presented better marginal fit on
shoulder preparations than chamfer preparations.

European Journal of Dentistry April 2012 - bol.6

30. | Preservation of the periodontium |

* Margins as smooth as possible
* Kept clean by the patient

* Supragingival placement of finish lines whenever
possible!

. subgingival finish lines 2.0 mm from alveolar crest

Herbert T. Shillingburg 3" edition

31. Biologic width

* The biologic width is defined as the dimension of the soft

tissue, which is attached to the portion of the tooth coronal
to the crest of the alveolar bone

* Biologic width (EA + CTA) dimensions -
— Anterior teeth 1.75mm
— Premolars 1.97mm

— Molars 2.08mm |
J Clin Periodontol 2003; 30: 379-385

32. Margin placement

ie
Supragingival margin | Equigingival margins | Subgingival margin
Placed in non-esthetic At the crest of the Below the gingiva
area marginal gingiva
Least impact on More impact on the Greatest biologic risk
periodontium periodontium

More plaque retentive May violate gingival
attachment apparatus

33. Margin placement guidelines |

> If the sulcus probes 1.5mm or less, place the
margin 0.5mm below the gingival crest

> If probing depth more than 1.5mm — place the
margin half the depth of the sulcus below the
crest

>If probing depth more than 2.0 mm —
Gingivectomy is advocated

Indian Journal of Clinical Practice, Vol. 23, No. 11, April 201 3

34. OBleeding

OGingival recession

=— Subgingival restorations

Orkin et al ”

Supragingival position of the crown margin

Silness
Margins below the gingival margin «C2

Indian Journal of Clinical Practice, Vol. 23, No. 11, April 2013 À

35. Finish line exposure | a * >.

* Mechanical
— Copper tube/band
— Rubber dam
+ Chemomechanical (retraction cord)

— Caustic chemicals — sulfuric acid, trichloracetic acid,
negatol, zinc chloride

— Racemic epinephrine
— Aluminium chloride, alum, aluminium sulfate, ferric
sulfate
* Rotary curettage/ gingettage
* Electrosurgery

36. GOOD MORNING

Beginning well is a momentary thing;

finishing well is a life long thing.

MOHD.SIBGHATUL

IST PG STUDENT

37. Extracoronal restoration - Full veneer crowns

0

¿$e

Metal ceramic crown

Full metal crown

All ceramic crown

38. Full veneer crowns

Full metal

39. Full veneer crown

own

structural durabil

a
»
=
Chamier
= =
Radial Shoulder marginal integrity
u periodontal presorvations SN periodontal praservation
structural durabity
a
7 —— Axial Reducti
= retention and resi
2
2

Incisal Notch
structural durability

40. Full veneer crown

Chamfer

Gingival Bevel
(Optional) marginal into
marginal integrity 1 penodontal pre

Axial Reduction
retention and resist
structural durability

vation

Radial Shoulder lance
patiodontal preservations.

structural

Functional
Cusp Bevel

structural durabaity

Wing
retention and resistance
presorvation of tooth structure

Planar Occlusal
Reduction

structural dur

lity

41. Full veneer crown
ALL CERAMIC CROWN

Radial Shoulder
marginal integrity N
atruch

periodontal p
Vertical

Le Lingual Wall

retention and resstanco

Axial Reduction
and resestance SX Concave Cingulum
tural durability Reduction

structural durability
E
Rounded Angles
structural durability

42. Partial veneer crowns

structural durability

structural durability

Planar Occlusal
Reduction

structural durability

Proximal Groove
marginal integrity 2 retention and resistance
periodontal preservation = structural durability
Axial Reduction : FAA Proximal Flare

retention and resistance ———

marginal intogrity

Buccal Bevel
marginal intogrity

Occlusal Offset
structural durability

44. A conservative method of
restoring the -
ODiscolored

O Pitted

UOFractured anterior teeth.

45. According to sturdavent |

— PLV can be classified into
1. Partial veneers F zu
2. Full veneers

a) Window preparation | Cl |

b) Incisal lapping

46. Incisal edge reduction |

> Four basic preparation designs for the incisal edge
reduction.........

Walls et al. Crowns and other extra-coronal restorations: Porcelain laminate veneers :British
dental journal 2002;193 : 2:73-81

47. Cervical finish line

OL ong chamfer with about a 0.4 mm maximum depth.

« Proximal finish line

— Incisal third of the tooth - not to extend beyond the
contact point

)

Walls et al, Crowns and other extra-coronal restorations: Porcelain laminate veneers :British
dental journal 2002:193 : 2:73-81

48. Finish lines for intracoronal restorations |
Lipp A Sr
1
ee ,

49. | Enamel pattern

Occlusal surface

Axial surface

Cavity wall angulation

Convergent
Depending
upon the
buccolingual
width

Divergent

Parallel

A
\
7 | Clincal significance

Cavity prepared

Amalgam

Cast gold Bevels

50. Noy’s criteria | KY :

1.

2.

3.

4.

Enamel must be supported by sound dentin

The enamel rod which form the cavosurface angle must
have their inner end resting on sound dentin

Enamel rods forming cavosurface angle should be

covered with restorative material

Angular cavosurface angles should be trimmed

M.A Marzouk

51. | Terminologies |

Cavosurface angle Cirumferential tie

52. Bevels

QPlane of a cavity wall/ floor directed away from
the cavity preparation

QAny angle other than 90° between a tooth cut and
a cavity wall in the preparation of the tooth cavity

53. Classification

. Partial bevel
. Short bevel

. Long bevel

. Full bevel

. Counter bevel

Don Eh © D —

. Hollow ground (concave) bevel

54. Partial bevel
* Not more than two third the thickness of enamel
+ Used to trim weak enamel rods at the margins

Short bevel
* Entire enamel wall but not dentin

Long bevel

>, fe Entire enamel+1/2 of dentinal wall
| + Used for first three classes of cast alloys
* Preserves internal box form of resistance and
retention feature

Full bevel

+ Entire enamel and dentin

+ Resistance and retention form hampered
+» All classes of cast alloys

55. Hollow ground (concave) bevel
! * Concave form
+ For base metal alloys and castable ceramics
* Improves castability
* Provides bulk y

Counter bevel

+ Cusp capping

* Opposite to axial cavity wall on facial
or lingual surfaces

56. Bevel with different restoration | / \
* Amalgam ........ x T

* Composite .....

57. Cavosurface Margins in Direct restorations

Cavosurface angle Gingival margin

90" cavosurface
angle for amalgam

58. Margins in Direct tooth coloured
restorations |

* General concepts
Minimal extension
Pulpal and/or axial walls of varying depth
Enamel bevel

Butt joint on root surfaces

ob D |

Tooth preparation walls must be rough

59. Direct tooth coloured restoration |

+ Five designs of tooth preparations for composite
restorations are...
1. Conventional
+ Similar to amalgam cavity preparation designs
2. Beveled conventional
+ Similar to conventional but bevels given
3. Modified
+ Scooped out design

4. Box only Az
+ Proximal caries S SOS.

5. Slot preparation designs.

60. Anterior composite restoration |

61. Anterior composite restoration |

Class IV restoration Bevelled conventional

—+ Bevel

62. Anterior composite restorations

According to Albers
* Class IV cavity preparations
— Chamfer design
— Bevelled margins
1. Chamfer design
— Imm long or half the length of fracture
— Most durable restorative margins
— Stair stepping — better esthetics

63. Anterior composite restorations

* Bevelled margins
— Alternative to stair step chamfer
— 2-3mm bevel
— Better esthetics
— Bevels ina curve better than scalloped margins
— Drawback
* Margins not as durable as chamfer
* Chipping

64. | NX pal GO
Mo | OPO OPO
000 Q 70 OPO
apa 020 C0

65. Anterior composite restorations |

Class V restoration
Bevelled conventional

66. Posterior composite restoration |

Enamel margin design _

90 degree exit 45 degree bevel

Concave bevel (chamfer) |

67. Comparative evaluation of
internal bevel and a
conventional butt joint at
the approximal surface of
Class II restoration

+ Internal bevel at the cervical cavosurface of class
2 composite restoration reduced marginal
microleakge as compared to conventional butt
joint

JIOH, October 2010, Volume 2 (Issue 3)

68. | a je :
Margins in direct gold restoration|

* Cavosurface margin bevel —

O Partial bevel

OWidth — not more than 0.2mm |
(130-40 degrees metal margin \ q
OGingival margin bevelled if on enamel U)
OShould include atleast 1/4! enamel wall WZ

Q Wedelstaedt chisel used

* Allows coverage of the enamel margin with the
restorative material

69. GOOD MORNING

Don’t stop when you are tired.

STOP when you are DONE

MOHD. SIES HATULLAH KHATIB

TPG STUDENT

70. Margins in Indirect restorations

71. Indication |

«Large restoration
*Endodontically treated
teeth

«Teeth at risk for fracture
*Removable
prosthodontic abutment

Contraindication |

*High caries rate
«Young patient
*Esthetics

«Small restoration

Advantage

Strength
*Biocompatibility
*Low wear

*Control of contour and
contact

Disadvantage

*Number of appointment
*Temoprary
*Cost

*Technquie sensitive
*Splitting force

72. __ Cast metal inlay |

* It is as intracoronal cast restoration replacing one
or more, but not all of the cusps fabricated
extrorally using direct or indirect wax pattern.

75. Flare

* Basic part of circumferential tie

* Similar to long bevel

* Angulations of 45 degrees to inner dentinal wall

76. « Function -
USame as bevels

ÜBrings facial and lingual margins to self —
cleansable areas

» Indication -
Y Normal contacts

Y Minimum extension of caries in the
buccolingual dimension

77. Flare |

Secondary — E.
Secondary

Primary
Flat plane superimposed peripherally to a
primary flare
Prepared solely in enamel, sometimes includes
dentin
No definite angulation — depends on
involvement and extent
40 degrees marginal metal and 140 degrees
marginal enamel desirable

78. Indications

Y Indirect wax pattern
Y Broad contact areas
Y Wide extension of caries buccolingually

¥ Overcome undercuts in the cervical aspect of facial and
lingual proximal walls in ovoid teeth

Function |

QExtends margins into embrasures
OStronger enamel margin produced
(40 degree marginal metal

79. * Secondary flare omitted in mesiofacial
proximal wall of —
Maxillary premolars
Maxillary molars

* Burs No. 8862/ 169 L / paper discs

80. Tooth coloured inlays

+ Ceramic and Composite inlays

— Facial, lingual, and gingival margins of the
proximal boxes - clear the adjacent tooth by at
least 0.5 mm

— 90-degree cavosurface margin desired
— Minimal gingival margin extension - margins in
enamel preferred for bonding and impression

81. | Margins for onlay

82. Onlay

* According to sturdavent

— The cast metal onlay by definition caps all of the
cusps of a posterior tooth and can be designed to
help strengthen a tooth that has been weakened by
caries or previous restorative experiences.

85. Extracoronal restoration

Intracoronal restoration

86. Restoration Finishline Finish Line Purpose

design dimension
Full metal Chamfer, knife- 0-Imm Marginal integrity,
edge, shoulder structural

with bevel durability

87. Restoration Finishline Finish Line Purpose

design dimension
Metal ceramic Labially Labially Removes
shoulder, 1.2mm unsupported
shoulder with Lingually enamel, structural
bevel, sloping 0.5mm durability,
shoulder marginal integrity

Chamfer

88. Restoration

All ceramic

Finish line
design

Shoulder,
heavy
chamfer,
rounded

shoulder

Finish Line

Purpose
dimension
0.7 - Imm Marginal integrity
Structural
durability
Esthetic

89. Restoration

Finish line d

gn Finish Line
dimension

Purpose

Partial
veneer
crown

Chamfer 0-1mm Marginal integrity,
Structural durability
Proximal flare Marginal integrity
Occlusal/incisal Structural durability
offset
Buccal/incisal Marginal integrity,
bevel Remove
unsupported enamel
Occlusal shoulder | Imm Structural durability

90. Restoration Finishline Finish Line Purpose
design dimension

Porcelain Long chamfer 0.3-0.5mm Marginal integrity,
laminate veneer conserves tooth
structure, better
etching

91. Restoration

Cavosurface margin

Margin

Amalgam

design features
Butt joint 90 degrees Strongest
margin for
amalgam
|
b
Gingival finish line 15-20 degrees | Remove
unsupported
At Gingival third- enamel

beveled

At Middle third/root
surface — no bevel

92. According to Sturdavent

Restoration Cavosurface margin Margin features Purpose

design
Conventional — no 90 degrees Lesion on
bevel margin root- no
Anterior enamel to
Direct bevel
Composite
Restoration Bevelled 45 degrees Increased
conventional 0.25-0.5mm surface area
(partial , long) for etching

and bonding

93. According to Albers

Restoration Cavosurface margin Margin features Purpose

design
Imm or half the
Anterior length of defect | Durability
direct Chamfer
composite Half the depth of
restoration enamel

Bevelled (scalloped) 2-3mm Esthetics

94. Posterior direct composite restoration

Restoration

Cavosurface

margin design

Margin
features

purpose

Occlusal

Butt joint

Bevel (partial,
long)

90 degrees

45-70 degrees
0.25 — 0.5mm

Enamel rod ends
exposed

Conserves tooth
structure
Better sealing

Proximal

Long bevel

0.5mm wide
45 degrees

1. Increased surface
area for etching and
bonding

2. Margins placed in
accessible areas

3. Reduced marginal
leakage

95. Restoration

Gingival

Posterior direct composite restoration

Cavosurface
margin design
Partial bevel

Butt joint ....
close to CEJ

Margin
features

1/3rd — % the
enamel wall

90 degrees

purpose

Better sealing

Exposes enamel rod
ends internally
Better sealing than
butt joint

Direct gold
restoration

Partial bevel

<0.2mm

30-40 degrees metal
margin

96. Cast metal
inlay

ee i nee
Partial
bevel

97. INDIRECT RESTORATION |

Restoration Cavosurface Margin features Purpose
margin design
Occlusally — Width — 1/4" the | + 30-40 degrees
Cast metal | * partial bevel | depth of respective | marginal metal —
inlay wall burnishible, lap
+ Steep cusp — 140-150 degrees joint
no bevel cavosurface margin * Strongest
cavosurface

margin

98. Restoration

INDIRECT RESTORATION |

Cavosurface

Margin features

purpose

Cast metal
inlay

margin design

Gingivally —

+ Partial bevel

* Reverse bevel —
sufficient gingival
floor width

Width - 0.5-1mm
150 degrees
cavosurface

margin

* 30-40 degrees
marginal metal —
burnishable

«Minimizes cement
line

* Strongest
cavosurface margin

+ Removes
unsupported enamel

Resistance to
dislodgement against
occlusal forces

99. Restoration

INDIRECT RESTORATION |

Cavosurface
margin design

Margin features

Purpose

Cast metal
inlay

Primary flare

45 degrees to
inner dentinal
wall

similar to long
bevel

30-40 degrees
marginal metal

«Increases retention
*Self-cleansable
areas

Secondary flare

Placed entirely in
enamel
sometimes dentin

No particular
angulation

* Acute marginal
metal
* Strong enamel
margins
*Extends margins to
embrasures

100. Restoration

INDIRECT RESTORATION |

Cavosurface

margin design

Margin features

Purpose

Tooth Bevels and 90 degrees butt + Material bulk
coloured | flares — hollow joint
inlay ground * Better Resistance
to stresses
Gingival 90 degrees butt * Removes
margin - joint unsupported
hollow ground enamel

Or no bevel —
middle
third/cementum

+ Material bulk

* Better Resistance
to
stresses

101. Restoration

INDIRECT RESTORATION __ |

rgin design

gin features

purpose

Cast metal
onlay

Counter bevel

Facial and lingual
margin of reduced
cusp

Structural durability,
marginal integrity,
retention, stress
distribution 30-40
degrees marginal
metal

Just gingival to tip
and ridge crests

Flat sometimes
partial bevel given if
unsupported enamel

remains

Increased resistance
and retention

Conservation of tooth
structure

Gingival bevel and
secondary flares
similar to inlay

102. INDIRECT RESTORATION

Restoration Margin design Margin features purpose
Cusp protection — Exaggerated Increased
capping hollowground retention
counterbevel — Structural
occlusal table to durability
Tooth facial termination
coloured of the preparation

onlays

Shoulder — Imm

Gingival margins
and proximal
margins — same as
tooth coloured
inlays

103. Conclusion... |

* While choosing a configuration of finish line for
extracoronal restoration one must consider the
advantages and disadvantages of various finish
lines

* While deciding about the placement of the finish
line , periodontal health and esthetics have to be
equally weighed

* For the intracoronal restoration, type of
restorative material being used and the enamel
pattern play an important role

104. Conclusion...

* For the restorative materials with low tensile
strength like amalgam and ceramics, butt joint
is preferred

« Bevels and flares are used for metals because
of their property of burnishability

* Angle and width of bevels and flares also
require careful placement

105. Conclusion... |

“We shall neither fail nor falter , we shall not
weaken or tire, give us the tools and we will
finish the job”

- Winston Churchill

* Hence every effort should be made to design
and prepare the marginal peripheries to create
the most favourable relationship with the
restoring casting and luting cement.....

106. References |

Contemporary Fixed Prosthodontics 3" edition

Herbert T. Shillingburg 3" edition

A.J. Hunter JPD 1990;64

Journal of Clinical and Diagnostic Research. 2015 Aug, Vol-
9(8)

European Journal of Dentistry April 2012 - Vol.6

Indian Journal of Clinical Practice, Vol. 23, No. 11, April 2013
Walls et al. Crowns and other extra-coronal restorations:
Porcelain laminate veneers :British dental journal 2002;193 :
2:73-81

Sturdavent 4' edition

JIOH, October 2010, Volume 2 (Issue 3)

J Appl Oral Sci. 2012;20(2):174-9