Types of crown lengthening,maintainence of biological width,techniques of crown lengthening.

2.  Introduction
 Rationale
 Sequence of treatment
 Biologic width
 Ferrule
 Crown lengthening and techniques
 Conclusion
 Points to remember
 References

3.  Periodontal health is the sine qua non, a prerequisite of
successful comprehensive dentistry.
 Active periodontal infection must be treated and controlled
before the initiation of restorative , Aesthetic and implant
dentistry
 To achieve the long term therapeutic targets of comfort, good
function, treatment predictability ,longevity and maintainence
care.

4. To ensure stable gingival margins before tooth
preparations.
To provide for adequate tooth length for retention, access for
tooth preparation, impression making, tooth preparation and
finishing of restorative margins in anticipation of restorative
dentistry
To correct the occlusion prior to any restoration for a
long term stability and comfort

5.  To prepare periodontium for restorative dentistry-
CONTROL OF ACTIVE
DISEASE
•Emergency treatment
•Extraction of hopeless teeth
•Oral hygiene instructions
•SRP
•Reevaluation
•Periodontal surgery
•Adjunctive orthodontic
therapy
PREPROSTHETIC
SURGERY
•Management of
mucogingival problems
•Preservation of ridge
morphology after tooth
extraction
•Crown lengthening
procedures
•Alveolar ridge
reconstruction

6. “When the clinician is presented with
a patient with any stage of periodontal
involvement, this condition must be
treated before one can contemplate
any restorative dentistry”

7. The appearance of the gingival tissues surrounding the
teeth plays an important role in the esthetics of the
mouth.
Abnormalities in symmetry and contour can significantly
affect the harmonious appearance of the natural or
prosthetic dentition

8. nowadays, patients have a greater desire for more
esthetic results which may influence treatment
choice.
An ideal appearance necessitates healthy and
inflammation-free periodontal tissues

9. In the 21st century, the dental practitioner
must be prepared to meet the challenges
necessary to provide care that will result in a
true condition of oral health
If dentition is affected with significant caries
or sub-gingival fractures, the dentist weighs
the clinical findings and patients’ concerns in
the balance to determine if the tooth or teeth
should be extracted or restored.
A dentist may opt to use crown-
lengthening therapy to expose solid tooth
structure and thus to facilitate restorative
therapy.

10. The concept of crown lengthening was introduced by
D.W Cohen (1962)

11. • Surgical procedure designed to increase the
extent of supragingival tooth structure for
restorative and esthetic purposes.
• It is done to increase the clinical crown length
without violating the biologic width.
CLINICAL CROWN-crown visible in the oral cavity
ANATOMIC CROWN- crown till the CEJ(incisal edge to CEJ)

12. The rationale of crown lengthening is to re
establish the biologic width (e.g. the natural
distance between the base of the gingival
sulcus and the height of the alveolar bone) in a
more apical position to avoid a violation that
may result in bone resorption, gingival
recession, inflammation or hypertrophy.

13.  To provide retention form to allow for proper tooth
preparation
 Impression procedures
 Placement of restorative margins
 To adjust gingival levels for esthetics.

14. treatment of sub gingival caries, crown or
root fractures, altered passive eruption,
cervical root resorption and short clinical
abutment.
To produce a ferrule for restoration
To access a perforation in the coronal third
of the root

15. To relocate margins of
restorations that are impinging on
biological width.
Aesthetics
Short teeth
Uneven gingival contour
Gummy smile.

16.  Inadequate crown to root
ratio
 Non restorability of caries or
root fracture
 Esthetic compromise
 High furcation
 Inadequate predictability
 Tooth arch relationship
inadequancy
 Compromise of adjacent
periodontium or esthetics
 Insufficeient restorative space
 Non maintainability

17. Clinical evaluation
 Sulcus depth
 Biologic width
 Osseous crest
 Pulpal involvement
 Apical extent of fracture
 Gingival health & Amount of
attached gingival tissue
 Furcation location
 Loss of mesial distal or occlusal
space
 Anticipated final margin
placement
 Lip line (at rest and smiling)

18. Level of
alveolar crest
Apical extent
of fracture or
caries
Pulpal
involvement
Root length
Root trunk
Furcation
Crown to root
ratio
Root trunk
length

19. •Defined as the
physiologic dimension of
the junctional epithelium
and connective tissue
attachment.
•Measurement is relatively
constant-2mm+/_30%
(2.04mm).
•Healthy gingival sulcus-
0.69mm
•The Original Concept of
‘biological width’, arise from
the work of Garguilo ,Wentz and
Orban (1961)- who gave the
dentogingival complex and
established the dimensional
averages as 2.04mm
•Biologic width is essential for
preservation of periodontal
health and removal of irritation
that might damage the
periodontium

20. • The dimension of biologic width is not constant, it
depends on the location of the tooth in the alveola,
varies from tooth to tooth, and also from the aspect
of the tooth. Its constancy can only be found in
healthy dentition.
• Infringement (neglecting/violating) on the biological
width by the placement of a restoration within its
zone result in gingival inflammation, pocket
formation and alveolar bone loss.

21. • stated that these dimensions can vary
considerably, with epithelial attachment
ranging from 1-9 mm, although
dimensions for CT attachment are
generally less variable.
Padbury etal (2003)
• combined epithelial + CT attachment of
2mm with 1-2 mm for restorative finish
line, thus recommending 3.5-4 mm.
Rosenberg etal (1980)
‘Owing to the concept of ‘biologic width’ there should be 3 mm
(recommended) of supracrestal tooth tissue between bone and the margins
of the restoration’.

22.  Some authors have stated different concepts on biologic width.
 In contemporary practice, it generally is accepted that a 3-mm
distance would significantly reduce the risk of periodontal
attachment loss induced by subgingival restorative margins.
 The margin placement should be no more than 0.5 mm into
gingival sulcus – to avoid damage to the ‘biologic width’ and
facilitate plaque control.

23. In contemporary
practice, it
significantly
reduce the risk of
periodontal
attachment loss
induced by
subgingival
restorative
margins.
It serves to protect
against invasion
from bacteria and
other foreign
materials any
violation to the
biologic width
leads to chronic
inflammation.
Moreover, results
from an animal
investigation
involving
histologic
evaluation
indicated that
restorative
margins impinging
on the osseous
crest may result in
bone resorption
So the authors have reasoned that “adding the 1 mm to the average 2 mm of the
biologic width establishes a minimum dimension of 3 mm coronal to the alveolar crest
is necessary to permit proper healing and proper restoration of the tooth

25.  Clinical method-
If a patient experiences tissue discomfort when the restoration
margin levels are being assessed with a periodontal probe, it is a
good indication that the margin extends into the attachment and
that a biologic width violation has occurred

26.  The signs of biologic width violation are:
 Chronic pain and progressive gingival
inflammation around the restoration,
 bleeding on probing,
 Localized gingival hyperplasia with
minimal bone loss,
 Gingival recession, pocket formation,
 clinical attachment loss and alveolar
bone loss.

27.  The biologic width can be identified by probing under local
anesthesia to the bone level (referred to as “sounding to bone”)
and subtracting the sulcus depth from the
resulting measurement.
 If this distance is less than 2 mm at one
or more locations, a diagnosis of
biologic width violation can be confirmed.
 Radiographic interpretation –
 Can identify interproximal violations of biologic width, but are
not of diagnostic because of tooth superimposition

28. Kois (1994) stated that only 3mm is necessary to satisfy the
requirements for a stable biologic width.

29.  Kois in 2000, proposed three categories of biological width
based on the total dimension of attachment and the sulcus
depth following bone sounding measurements.
 Namely: normal crest, high crest and low crest.
• the mid-facial measurement is
3.0 mm and the proximal
measurement is a range from 3.0
mm to 4.5 mm.
•Normal Crest occurs
approximately 85% of time. In
these cases, the gingival tissue
tends to be stable for a long term.
•Therefore, a crown margin
which is placed 0.5 mm
subgingivally tends to be well-
tolerated by the gingiva.
NORMAL CREST

30. •High Crest is an unusual finding in
nature and occurs approximately 2%
of the time. There is one area where
High Crest is seen more often: In a
proximal surface adjacent to an
edentulous site.
• In the High Crest patient, the mid-
facial measurement is less than 3.0
mm and the proximal measurement
is also less than 3.0 mm in this
situation.
•It is commonly not possible to
place an intracrevicular margin
because the margin will be too close
to the alveolar bone, resulting in a
biologic width impingement and
chronic inflammation.
HIGH CREST

31. • The mid-facial measurement
is greater than 3.0 mm and the
proximal measurement is
greater than 4.5 mm.
•Low Crest occurs
approximately 13% of the
time.
• Traditionally, the Low Crest
patient has been described as
more susceptible to recession
secondary to the placement of
an intracrevicular crown
margin.
LOW CREST

32. When retraction cord is placed subsequent to the crown
preparation, the attachment apparatus is routinely injured. As
the injured attachment heals, it tends to heal back to a
Normal Crest position, resulting in gingival recession.
LOW CREST STABLE LOW CREST UNSTABLE
Some Low Crest patients are susceptible to gingival recession
while others have a quite stable attachment apparatus. The
difference is based on the depth of the sulcus, which can have a
wide range.

33. LOW CREST
Recession

34. This allows the operator to determine the optimal position of margin
placement, as well as inform the patient of the probable long-term
effects of the crown margin on gingival health and esthetics.
Based on the sulcus depth the following three rules can be used to place Intra-
crevicular margins:
Rule 1
• If the sulcus probes
1.5 mm or less, the
restorative margin
could be placed 0.5
mm below the
gingival tissue
crest.
Rule 2
• If the sulcus probes
more than 1.5 mm,
the restorative
margin can be
placed in half the
depth of the sulcus.
Rule 3
• If the sulcus is
greater than 2 mm,
gingivectomy could
be performed to
lengthen the tooth
and create a 1.5 mm
sulcus. Then the
patient can be
treated as per rule 1.

35.  A clinician is presented with three options for margin placement:
1. Supragingival- It has the least impact on the periodontium. This margin location
has been applied in non-esthetic areas.
2. Equigingival- The use of equigingival margins traditionally was not desirable
because they were thought to favour more plaque accumulation than
supragingival or subgingival margins, and therefore result in greater gingival
inflammation.
3. Subgingival -Restorative considerations (caries and tooth deficiencies) will
frequently dictate the placement of restoration margins beneath the gingival
tissue crest. Investigators have correlated that sub gingival restorations
demonstrated more quantitative and qualitative changes in the micro flora,
increased plaque index, gingival index, recession, pocket depth and gingival fluid

36.  A ferrule is a metal ring or cap intended for strengthening.
 Glossary of Prosthodontic Terms defines a ferrule as a metal
band or ring used to fit the root or crown of a tooth
 Sorensen and Engelman redefined the ferrule effect as “a 360-
degree metal collar of the crown surrounding the parallel walls
of the dentine extending coronal to the shoulder of the
preparation.”

37. Ferrule length is nothing but extending the tooth preparation 1.5
mm below the foundation restoration to permit the occlusal
forces to be dispersed onto the periodontal ligament rather than
concentrating stresses at the post and core intraradicularly, which
can increase the likelihood of failure of the tooth or the
restoration
It is still controversial & research is still going on ferrule length
whether to give it or not to give, some authors are against giving
the ferrule effect & some recommend to give ferrule height of 1-
2mm that is exposure of additional tooth structure & it is mostly
recommended in endodontically treated teeth .

38.  Smukler & Chaibi (1997) recommended some of the following
pre surgical analysis
Determine the finish line prior to surgery
If non determinable it should be anticipated
Transcrevicular, circumferential probing prior to
surgery is performed for establishing the biologic
width-(surgical and contralateral site)
 The biologic width requirements will determine the level of alveolar
bone removal

39.  The combination of biologic width & prosthetic requirements
determine the total amount of tooth structure necessary for
exposure.
 Tooth surface topography, anatomy, & curvature are analysed
for determining
a)osseous scallop
b)gingival form
 To plan a crown-lengthening procedure, a dentist must think in
three dimensions. In addition, he or she should be concerned
about the quantity and quality of residual gingival tissues left
behind after the resected tissue has healed completely.
Maynard and Wilson recommended a minimum of 3
mm of attached gingiva in the presence of
subgingival restorative therapy so care should be
taken before excising the tissue

40. CROWN
LENGTHENING
PERIODONTAL
SURGICAL
TECHNIQUE
ORTHODONTIC
TECHNIQUE

41.  Ernesto (2004) has proposed the following
classification:
1. Type I
2. Type II
3. Type III
4. Type IV

42. Characterized by sufficient gingival tissue coronal to
the alveolar crest
• No need of osseous contouring
No violation of biological width
• Gingivectomy/gingivoplasty can be done.
Advantages-May be performed by the restorative dentist.
Provisional restorations of the desired length may be placed
immediately

43. characterized by soft tissue dimensions that allow the
surgical repositioning of the gingival margin
No osseous re contouring, but temporary violation of
biological width.
STAGE 1
•Gingivectomy and
amount of crown
exposed
STAGE 2
After healing, flap surgery
is done and required
amount of ostectomy done
to maintain biologic width

46.  Advantages
 Will tolerate a temporary violation of the biologic width
 Allows staging of the gingivectomy and osseous contouring
procedures.
 Provisional restorations of the desired length may be placed
immediately
Disadvantages-
 Requires osseous contouring. May require a surgical referral

47. In type III bone sounding may reveal a scenario where
repositioning of the gingival margin will result in the exposure of
the osseous crest.
It is inappropriate to refer these patients without providing a
surgical template derived from a relevant esthetic blue print.
Surgical template is used that serve as a guide during surgery
following flap reflection

48. Relationship between anticipated clinical crown and
alveolar crest level is established and maintained through
bone cutting procedure.
Flaps repositioned coronally rather than apically to
maximise tissue preservation
After osseous surgery healing, gingivectomy is done to
establish gingival position without violating biological
width.

50. Gingival excision compromised by insufficient amount
of attached gingiva.
Apically positioned mucoperiosteal flap with or without
osseous contouring

51. I.Surgical –
A. Gingivectomy
 Conventional ( Scalpel or Kirkland knife)
 Laser
 Electrocautery
B. Surgical extrusion using periotome.
C. Internal Bevel Gingivectomy with or without ostectomy
(also referred as flap surgery with or without osseous
surgery)
D. Apical positioning of flap with or without ostectomy
II. Combined (Surgical & non surgical) -Orthodontic
Treatment

52.  Given by Robicsek (1884)
 Grant etal (1979) – Defined it as the excision of the soft tissue
wall of the pathologic periodontal pocket
Indications-
 Sufficient sulcular depth & keratinized tissue
 No violation of biologic width(> 3 mm)
 No exposure of bone

53. Firstly anasthetise the area
Then pocket height is measured with pinpoint marker
incisions should be bevelled at 45° to the tooth surface
Remove the excised gingival tissue
Carefully curette the granulation tissue
Removal of remaining calculus and necrotic cementum
Cover the area with surgical pack

54.  Used in Dentistry : 1980s
 Semiconducator diode laser : soft tissue laser
 In continuous-wave or gated-pulsed modes
 Operated in contact mode using a flexible fiber optic delivery
system.
 Laser light at 800 to 980 nm is used.
 Not interact with dental hard tissues
 Tissue penetration of a diode laser is less than that of the Nd:YAG
laser
 The rate of heat generation is higher.

55. The chief advantages of laser use are:
(1) Relatively bloodless surgical and postsurgical course;
(2) Ability to coagulate, vaporize, or cut tissues
(3) Sterilization of the wound site
(4) Minimal swelling and scarring
(5) Little mechanical trauma
(6) Reduction of surgical time
(7) High patient acceptance
(8) Reduced postoperative pain, possibly due to the protein coagulum
that is formed on the wound surface, thereby acting as a biologic
dressing and sealing the ends of the sensory nerves.

56. Surgical treatment is
faster and more
favorable
Unpleasant bleeding
during and after the
operation
It is necessary to
cover the exposed
lamina propria with
periodontal pack for
7 to 10 days.
Laser
Scalpel surgery
Scalpel
wound
Laser
Wound healing
Faster
Delayed

57.  Commonly used alternative to surgical excision of the soft
tissues
 It involves the use of high electrical energy, transmitted to
the tip of the instrument in the form of heat generated so as
to cauterize the tissues
 Caution must be taken as can cause irreparable damage to
bone (necrosis) and ‘Cementum burn’.
ELECTROSURGERY

58. SURGICAL EXTRUSION
USING PERIOTOME
Final restoration placed after 2 months.
Periodontal pack given. Suture removal done after 10 days.
Simple interrupted sutures placed for stability.
Teeth was extruded to the desired clinical position using a hemostat
Blade of the periotome was placed into the periodontal ligament space
and manipulated in walking motion to luxate the tooth without inducing
surgical trauma.
Local anesthesia was given

59. Clinical and radiographic evaluation at 3rd month suggest that
surgical extrusion technique offers several advantages such
as preservation of the interproximal papilla, gingival margin
position and no marginal bone loss compared with the other
conventional surgical techniques.

60.  It can also be referred as flap surgery with or without osseous
surgery.
 Flap Surgery Without Osseous Surgery :
 enough attached gingival should remain after the incisions are
made.
 The initial or inverse bevel incision is made depending upon
that how much crown exposure is required.
 The flap is then raised and after complete scaling and root
planning flap is then sutured back in position.

61. Flap surgery with osseous surgery:
 It is the most common procedure used for clinical
crown lengthening
 mucoperiosteal flap is raised and the alveolar bone is
reduced by ostectomy and osteoplasty
 Restorative procedures should be delayed until 3 to 6
months post surgery.
 Provisional restorations may be reshaped at 3 to 4
weeks post surgery but the margins should be placed
supragingivally.

62. Indication
 Crown lengthening of multiple teeth in a quadrant or sextant of the
dentition, root caries, fractures.
 Management of tooth wear cases. (often combined with osseous
recontouring)
 Less than 3 mm of the soft tissue between the bone and gingival
margin
 Less than adequate Attached gingiva
APICALLY REPOSITIONED FLAP FOR CROWN
LENGTHENING

63.  Contraindication
 Apical repositioned flap surgery should not be used during
surgical crown lengthening of a single tooth in the esthetic
zone.
1.Apically repositioned flap without osseous resection
 This procedure is done when there is no adequate width of
attached gingiva,
 biologic width of more than 3 mm on multiple teeth.
2.Apical repositioned flap with osseous reduction
 This technique is used when there is no adequate zone of
attached gingiva
 biologic width is less than 3 mm.
 The alveolar bone is reduced by ostectomy and osteoplasty, to
expose the required tooth length in a scalloped fashion, and to
follow the desired contour of the overlying gingiva

64. •at least 4 mm of sound tooth structure must be
exposed at time of surgery.
•During healing the supracrestal soft tissues will
proliferate coronally to cover 2-3 mm of the root
•1-2 mm of supragingivally located sound tooth
structure is left.

65. Step 1: Internal bevel incision given
(no more than 1 mm of crest of gingiva and directed to the crest of
bone)
Step 2: Crevicular incisions made
initial elevation of flap
Step 3: Vertical incisions made, extending beyond the MGJ

66. Step 4: Removal of all the granulation tissue
Osseous surgery, if required
Flap is displaced Apically
Step5 :sling sutures are placed around the
tooth to prevent flap from sliding more
apically
Periodontal dressing placed to prevent
coronal shift

67. 2 possible approaches to this procedure are –
Forced eruption followed
by minor Osseous resection
Forced eruption combined
by fibrotomy
SLOW ERUPTION RAPID ERUPTION
•Forced eruption-Heithersay and Ingber
• Two concepts of forced eruption-Starr
•Forced eruption of multiple teeth-Frank,used various techniques to extrude
teeth using removable devices or fixed brackets.

68. Disadvantages of forced eruption
 Disparity in root width between the erupted and the contralateral teeth
 Need for fixed appliances
 Subsequent retention of the orthodontically treated tooth
So, 2nd alternative- forced eruption followed by fibrotomy.
Disadvantages-
Patient must return biweekly basis for resection of the supracrestal fibres,
followed by root planing to the level of bone crest, until desired degree of
eruption is obtained.
 Retention period is required

69. COMPLICATIONS OF CROWN LENGTHENING
 Possible poor aesthetics due to 'black triangles’
 Root sensitivity
 Root resorption
 Transient mobility of the teeth.
 Gingival retraction – change of marginal gingiva
contour
 Clinical tooth crown higher than adjacent teeth
 Unfavorable crown-root relationship.

70. HEALING AFTER CROWN LENGTHENING
 Restorative procedures must be delayed until new gingival crevice
develops after periodontal surgery.
 In non esthetic areas, the site should be re-evaluated atleast 6 weeks
post surgically prior to final restorative procedures.
 In esthetic areas, a longer healing period is recommended to prevent
recession.
 Wise recommends 21 weeks for soft tissue gingival margin stability.
Therefore, restorative treatment should be initiated after 4-6 months.
The margin of the provisional restoration should not hinder healing
before the biologic width is established by surgical procedures.
 Shobha et al. in a study on clinical evaluation of crown lengthening
procedure had concluded that the biologic width can be re-
established to its original vertical dimension along with 2 mm gain
of coronal tooth structure at the end of six months.

71.  After a 2-3 week post surgery period, temporary crowns may be
used until there has been full healing and the gingival margin is in a
stable position.
 Before tooth restoration the gingiva should be healthy without any
sign of inflammation. Then these rules could be followed
• If gingival sulcus is 1.5 mm or less, then margins of restoration is
prepared to 0.5 mm subgingivally;
• If gingival sulcus is 1.5 – 2 mm, then margins of restoration is
prepared to 0.7 mm subgingivally;
• If gingival sulcus more than 2 mm, especially in esthetical area
from vestibular side, then gingivectomy is recommended and
margins of restoration is prepared to 0.5 mm subgingivally.

72. There are a number of alternative modalities that will correct the
esthetic problems. The decisive factor is what works best for the
individual patient.
Crown lengthening should not be attempted when tooth fractures
extend into the middle 3rd of the root
Although individual variations exist in the soft tissue attachment
around teeth, there is general agreement that a minimum of 3 mm
should exist from the restorative margin to the alveolar bone,
allowing for 2 mm of biologic width space and 1 mm for sulcus
depth.

73. The health of the periodontal tissues is dependent on properly
designed restorations. Incorrectly placed restoration margin and
unadapted restoration violates the biologic width.
If the margin must be placed subgingivally, the factors to be taken
into account are: Correct crown contour in the gingival third;
correct polishing and rounding of the margin; sufficient zone of the
attached gingiva; and, no biologic width violation by the margin
Repeated maintenance visits, patient co-operation and motivation
are important for improved success of restorative procedures with
pristine periodontal health.

74. If the tooth in question has a hopeless prognosis or the osseous surgical
procedure would create
• Poor Crown: root
• Furcation involvement
• Mobility, or
• Esthetics problems,
Crown lengthening should be avoided and extraction may be indicated

75. Biological width-
2.04mm(average 2mm)
Distance from alveolar bone
crest to marginal restoration-
3mm(average)
Ferrule effect-1.5-2mm
When deciding to place the
margin,keep it subgingivally
based on the sulcus depth rule.

76.  Crown lengthening: indications and techniques. Dent Update 2008
 Carranza’s clinical periodontology. 10th edition
 Surgical crown lengthening. Dent Update 2007;34:462-468
 Crown Lengthening Procedures- A Review Article Dr. Gunjan Gupta IOSR Journal
of Dental and Medical Sciences (IOSR-JDMS)
 Biological width: The silent zone Amit Parashar
 Tissue Management in Restorative Dentistry J. WILLIAM ROBBINS, DDS, MA
 Crown lengthening and restorative procedures in the esthetic zone-Perio 2000
 Surgical lengthening of the clinical tooth crown Liudvikas Planciunas, Alina
Puriene, Grazina Mackeviciene,2006
 Three different surgical techniques of crown lengthening: A comparative study
Ramya Nethravathy,2013
 Aesthetic crown lengthening MICHAEL G. JORGENSEN & HESSAM
NOWZARI-Perio2000
 Google images