This document discusses biologic width, which refers to the combined width of connective tissue and epithelial attachment above the alveolar bone crest. It provides definitions, a brief history of the concept, and an overview of the significance of maintaining biologic width to preserve periodontal health. Violations of the biologic width can lead to inflammation, attachment loss, bone loss, and recession. The document outlines methods for evaluating biologic width violations and categorizing biologic widths, and reviews surgical and orthodontic techniques for correcting violations. It also discusses considerations for margin placement in relation to biologic width for restorations.

1. Presented by:
Dr. Mitali Thamke
(II MDS)
BIOLOGIC
WIDTH

2.  Introduction
 Definition
 History
 Concept of biologic width
Sequel of biologic width violation
Evaluation of biologic width violation
 Categories of biologic width
INDEX

3.  Margin placement and biologic width
Supragingival margin
Subgingival margin
Equigingival margin
 Methods to correct biologic width violation
Surgical crown lengthening
Healing after crown lengthening
Complication after crown lengthening
 Orthodontic techniques
INDEX

4.  Biologic width in chronic periodontitis
 Biologic width in implants
 Summary
 References
INDEX

5. • The relationship between periodontal health and the
restoration of teeth is intimate and inseparable.
• Maintenance of gingival health constitutes one of the
keys for tooth and dental restoration longevity.
Felippe LA, 2003
• An adequate understanding of relationship between
periodontal tissues and restorative dentistry is
paramount to ensure adequate form, function and
esthetics, and comfort of the dentition.
Khuller N,2009
INTRODUCTION

6. • Despite an increased emphasis on the periorestorative
interface in restorative dentistry, many clinicians have
been unable to utilize the concept of biologic width in
a practical manner.
• Hence, the purpose of this seminar is to describe the
biologic width anatomy, evaluation and correction of
its violation by different methods.
INTRODUCTION

7. “ Biologic width is the combined width of connective
tissue and epithelial attachment superior to the crestal
bone.”
(Garguilo et al. 1961)
“ Biologic width is the sum of the space occupied by
the supracrestal fibres, junctional epithelium and the
gingival sulcus and has a proposed minimal dimension
of 3 mm.”
(Nevins and Skurow)
DEFINITION

8. “ The total dimension of the epithelial and
connective tissue attachment to the root.”
(Assif et al.1991)
“ The dimensions of space that the healthy
gingival tissues occupy above the alveolar bone.”
(Carranza 9th edition)

9.  The ‘‘epithelial attachment’’ around teeth was first described in
1921 by Gottlieb (1921).
 The ‘‘gingival crevice’’ or sulcus was later defined Orban B,
Mueller E. (1929), followed by description of the connective
tissue as three- dimensionally oriented fibers firmly connecting
tooth structures to the adjacent gingiva Feneis H(1952).
 Marfino, Orban and Wentz (1959), were the first to
demonstrate that the attachment of gingiva to tooth is
composed of gingival connective tissue attachment and
junctional epithelium.
HISTORY

10. In 1959, Sicher investigated the morphology of
epithelial and connective tissue attachments to the
teeth, described as the dentogingival junction .
In 1961, Gargiulo et al. quantified the vertical
components of this structure in human cadavers and
coined the term “biologic width”.
The denomination biologic width was conceived by
D Walter Cohen(1961).
HISTORY

11. Gargiulo et al. reported in 1961 a certain uniformity of the
dimension of some components of biologic width:
 Mean depth of the histologic sulcus is 0.69 mm,
 Mean junctional epithelium measures 0.97 mm (0.71-1.35 mm),
 Mean supraalveolar connective tissue attachment is 1.07 mm
(1.06-1.08 mm).
The total of the attachment is therefore 2.04 mm (1.77 to 2.43
mm) and is called the biologic width essential for preservation of
periodontal health and removal of irritation that might damage
the periodontium

12.  These findings were substantiated by
Vacek et.al. (1994)
 After detailed assessment of 171
cadaver tooth surfaces, the mean
measurements for sulcus depth,
epithelial attachment and connective
tissue attachment were found to be
1.34 mm, 1.14, and 0.77 mm,
respectively.
 Vacek et.al also realized that the
connective tissue attachment was the
most stable measurement, with the
least degree of variance.
 On the other hand, significant
variations were observed in epithelial
attachment ranging from 1.0 mm to
9.0 mm.

13. Palomo and Kopczyk
A minimum biologic width of only 1.0mm is necessary.
An additional 1 to 3mm of exposed root coronal to the
bone is required for the creation of a healthy gingival
sulcus.
(JADA – 1978)

14. Guang- yuan xie et.al done a study to evaluate the biologic width
in a chinese population.
(J. Of Oral science 2007)
Differences in biologic width among 4 different sites (mesial,
distal, buccal, lingual) as well as between anterior and posterior
teeth were compared
They concluded that
Mean B.W. – 2.17mm
Width of J.E. – 1.07 mm
Connective tissue – 1.10 mm
The B.W. varied among the 4 sites
( Mesially > Distally > Buccally > Lingually)
The width of posterior teeth was greater than that of anterior teeth.

15. 1. It acts as a barrier and prevents penetration of
microorganisms into the periodontium.
Fellippe et.al(2003)
2. Maintenance of biologic width is essential to preserve the
periodontal health and to remove any irritation that may
damage the periodontium.
SIGNIFICANCE OF BIOLOGIC WIDTH

16. There is a general agreement
that, placing restorative
margins within the biologic
width frequently leads to
gingival inflammation,
clinical attachment loss and
bone loss.
CONCEPT OF BIOLOGIC
WIDTH

17. Response to biologic width can be manifested in two
broad ways:
First response
Bone loss of unpredictable nature
Gingival tissue recession.
Body attempts to recreate room between the alveolar
bone and the margin to allow space for tissue
reattachment.

18. Second Response
 More common finding with deep margin placement.
 Bone level appears to remain unchanged but gingival
inflammation develops and persists.
(Carranza 9th edition)

19. Signs and Symptoms:
 Chronic pain
 Chronic progressive
inflammation of gingiva.
 Bleeding on probing
 Gingival recession
SEQUEL OF BIOLOGICAL
WIDTH VIOLATION

20.  Pocket formation
 Clinical attachment loss
 Gingival hyperplasia
 Unpredictable loss of alveolar bone
 Localized gingival hyperplasia with minimal bone loss

21. Radiographic Interpretation
Radiographic interpretation can identify interproximal
violation of biologic width.
However, since more common location of biologic width
violation is on the mesiofacial and distofacial line angles
of teeth, radiographs may not be diagnostic in all cases
EVALUATION OF BIOLOGIC WIDTH
VIOLATION

22. Sushma and Gauri(1994) have described a new innovative
parallel profile radiographic technique (PPR) to measure
the dimension of the dento gingival unit (DGU) and
hence the biologic width.
This technique could be used to measure both length and
thickness of DGU with accuracy, as it was simple,
concise, noninvasive and reproducible method.
PARALLEL PROFILE
RADIOGRAPHY

25. 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.
The signs of biologic width violation are:
• Chronic 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.
• Gingival hyperplasia is most frequently found in altered passive eruption
and subgingivally placed restoration margins.
Jorgic-Srdjak K,et.al(2003)
CLINICAL METHOD

26. This measurement must be
performed on teeth with
healthgingival tissues and
should be repeated on more
than one tooth to ensure
accurate assessment, and
reduce individual and site
variations.
BONE SOUNDING

27. The information obtained used to definitively diagnose
 Biologic width violations,
 The extent of correction needed, and
 The parameters for placement of future restorations

28. Kois(1996) proposed three categories of biologic width
based on the total dimension of attachment and the
sulcus depth following bone sounding measurements,
namely:
1. Normal Crest,
2. High Crest and
3. Low Crest
CATEGORIES OF BIOLOGIC
WIDTH

29. The margin of a crown should
generally be placed no close
than 2.5 mm from alveolar
bone.
Therefore, a crown margin
which is placed 0.5 mm
subgingivally tends to be well-
tolerated by the gingiva, and is
stable long term in the Normal
Crest patient.
NORMAL CREST

30. In a proximal surface adjacent to
an edentulous site.
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. More susceptible to recession
secondary to the placement of
an intracrevicular crown margin.
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

32. However, the Low Crest
attachment is actually more
complex because all Low Crest
patients do not react the same to
an injury to the attachment.
Some Low Crest patients are
susceptible to gingival recession
while others have a quite stable
attachment apparatus
LOW CREST, STABLE OR
UNSTABLE

33. Importance of determining crest category:
 To determine the optimal position of margin
placement
 To inform the patient of the probable long-term
effects of the crown margin on gingival health and
esthetics.

34. Based on the sulcus depth the following three rules
can be used to place intracrevicular margins:
 If the sulcus probes 1.5 mm or less, the restorative margin could
be placed 0.5 mm below the gingival tissue crest.
 If the sulcus probes more than 1.5 mm, the restorative margin
can be placed in half the depth of the sulcus.
 If the sulcus is greater than 2 mm, gingivectomy could be
performed to lengthen the tooth and create a 1.5 mm sulcus.
Freeman K et al. (2000)

35. Maynard and Wilson (1979)
Divided the periodontium into three-dimensions, all of which affect decision-
making during restorative therapy:
1. Superficial physiologic: Represents the free and attached gingival
surrounding the tooth.
2. Crevicular physiologic: Represents the gingival dimension from the
gingival margin to the junctional epithelium.
3. Subcrevicular physiologic: Is analogous to the biologic width described
(Gargiulo et al. 1961), consisting of the junctional epithelium and
connective tissue attachment.

36. A clinician is presented with three options for margin placement:
1. Supragingival
2. Equigingival, and
3. Subgingival locations
MARGIN PLACEMENT AND
BIOLOGIC WIDTH

37.  It has the least impact on the periodontium.
 This margin location has been applied in non-esthetic areas
due to the marked contrast in color and opacity of traditional
restorative materials against the tooth.
 With the advent of more translucent restorative materials,
adhesive dentistry, and resin cements, the ability to place
supragingival margins in esthetic areas is now a reality.
SUPRAGINGIVAL MARGIN

38. 1. Preparation of the tooth and finishing of the margin is easiest
2. Duplication of the margins with impressions that can be
removed past the finish line without tearing or deformation is
the easiest with supragingival margins.
3. Fit and finish of the restoration and removal of excess
material is easiest
4. Verification of the marginal integrity of the restoration is
easiest.
5. The supragingival margins are least irritating to the
periodontal tissue.
ADVANTAGES

39.  The use of equigingival margins traditionally was not
desirable because they were thought to train more
plaque than supragingival or subgingival margins and
therefore result in greater gingival inflammation.
 There was also the concern that any minor gingival
recession would create an unsightly margin display.
EQUIGINGIVAL MARGINS

40.  These concerns are not valid today, not only because
the restoration margins can be esthetically blended
with the tooth but also because restorations can be
finished easily to provide a smooth, polished interface
at the gingival margin..
 From a periodontal viewpoint, both supragingival
and equigingival margins are well tolerated

41.  The greatest biologic risk occurs when placing subgingival
or equigingival margins for finishing procedures, and in
addition, if the margin is placed too far below the gingival
tissue crest, it violates the gingival attachment apparatus
 When the restoration margin is placed too far below the
gingival tissue crest, it impinges on the gingival
attachment apparatus and creates a violation of biologic
width.
 Two different responses can be observed from the
involved gingival tissues.
SUBGINGIVAL MARGIN

42.  One possibility is that bone loss of an unpredictable nature and gingival
tissue recession occur as the body attempts to recreate room between the
alveolar bone and the margin to allow space for tissue reattachment.
 This is more likely to occur in areas where the alveolar bone surrounding
the tooth is very thin.
 Trauma from restorative procedures can play a major role in causing this
fragile tissue to recede.
 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.

43. Valderhaug in 1976
Placed crowns in 114 patients
Observed for 10 years
Margins were placed subgingivally, at the gingival margin and
supragingivally.
Subgingival margins- Increased gingivitis, pocket depth and loss
of attachment.

44. Wilson and Maynard in 1981
 0.5 mm. of unprepared tooth surface should remain between the finish line of
the prepared tooth and the junctional epithelium.
Nevins and Skurow in 1984
 Biologic width is 3mm in length.
Restoration placed at that level would actually terminate above the attachment and within
the gingival sulcus.

45. Fugazzotto, Silver and Johnson in 1985
 Locate margins subgingivally, 3mm coronal to bone and restoration terminate 1mm
above the base of the sulcus.
R.Williams in 1991
No restorative margin should be placed subgingivally since it causes :-
1. Plaque accumulation
2. Inflammation
3. Bacterial Shifts
4. Mechanical irritation
5. Attachment Loss

46. Flores-de-je-Coby et al (1989) studied the effects of
crowns margin location on periodontal heath and
bacterial morphotypes in humans 6-8 weeks and 1 year
post insertion.
Subgingival margins demonstrated increased plaque,
gingival index scores, and probing depths. Further more,
more spirochetes, fusiforms, rods, and filamentous
bacteria were found to be associated with subgingival
margins

47. Intracrevicular margins is clinical alternative.
“Defined as margin disappearing from the sight just below the gingival crest
without impinging on the junctional epithellium.”
Margin of restoration should not be deeper than 0.5 mm into the
sulcus.
If sulcus is between 0.5 mm to 1.0 mm. Then the margin of
restoration should not enter the crevice but terminate just at or
above the gingival margin.

48. To avoid encroaching on the biological width the tooth
preparation must terminate at least 2mm coronal to the crest of
alveolar bone.
(Tylman, 8th edition)

49. Biologic width violations can be corrected by
1. Either surgically removing bone away from proximity to the
restoration margin,
2. Orthodontically extruding the tooth and thus moving the margin
away from the bone.
METHODS TO CORRECT BIOLOGIC
WIDTH VIOLATION

50. During Crown lengthening- 3mm of supracrestal tooth
structure be present above bone.
Ingber al.(1977)
Indication:
Inadequate clinical crown for retention due to extensive caries, subgingival
caries or tooth fracture, root perforation, or root resorption within the
cervical 1/3rd of the root in teeth with adequate periodontal attachment.
Short clinical crowns.
Placement of sub gingival restorative margins.
Unequal, excessive or unaesthetic gingival levels for esthetics.
SURGICAL CROWN
LENGTHENING

51. Planning veneers or crowns on teeth with the gingival margin
coronal to the cemetoenamel junction (delayed passive eruption).
Teeth with excessive occlusal wear or incisal wear.
Teeth with inadequate interocclusal space for proper restorative
procedures due to supraeruption.
Restorations which violate the biologic width.
In conjunction with tooth requiring hemisection or root resection.
Assist with impression accuracy by placing crown margins more
supragingivally.

52. Contraindication :
Deep caries or fracture requiring excessive bone removal.
Post surgery creating unaesthetic outcomes.
Tooth with inadequate crown root ratio (ideally 2:1 ratio is
preferred)
Non restorable teeth.
Tooth with increased risk of furcation involvement.
Unreasonable compromise of esthetics.
Unreasonable compromise on adjacent alveolar bone support.

53. External bevel gingivectomy
It can be used only in situations with hyperplasia or
pseudopocketing (> 3 mm of biologic width) and presence of
adequate amount of keratinized tissue.
Internal bevel gingivectomy
Reduction of excessive pocket depth and exposure of additional
coronal tooth structure in the absence of a sufficient zone of
attached gingiva with or without the need for correction of osseous
abnormalities requires internal-bevel gingivectomy.

54. Indication
Crown lengthening of multiple teeth in a quadrant or sextant of
the dentition, root caries, fractures.
Contraindication
Apical repositioned flap surgery should not be used during
surgical crown lengthening of a single tooth in the esthetic zone.
Apically repositioned flap without osseous resection
This procedure is done when there is no adequate width of
attached gingiva, and there is a biologic width of more than 3 mm
on multiple teeth.
APICAL REPOSITIONED
FLAP SURGERY

56. This technique is used when there is no adequate zone of attached
gingiva and the 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.
As a general rule, at least 4 mm of sound tooth structure must be
exposed, so that the soft tissue will proliferate coronally to cover 2-3
mm of the root, thereby leaving only 1-2 mm of supragingivally located
sound tooth structure.
(Pontoriero & Carnevale 2001)
APICAL REPOSITIONED FLAP
WITH OSSEOUS REDUCTION

58. Sugumari et al.(1973) in a report on surgical crown lengthening
with apical repositioned flap with bone resection performed in
the fractured maxillary anterior teeth region, showed satisfactory
results both in terms of functional (restoring biologic width) and
esthetic outcomes.

59. Assif et al in 1991, recommended 4mm and Wagenbery et al in 1989
recommended a 5 to 5.25 mm. exposure of supracrestal tooth
structure after crown lengthening.
Dibart et al. (2003),
A preoperative distance of 4 mm. between the furcation and the
bone crest is needed to not put the tooth at risk for furcation
exposure.
Sharron K Lanning et al (2003), evaluate the positional changes of
the periodontal tissues particularly the biologic width, following
surgical crown lengthening in human subjects and concluded that
During surgical crown lengthening, the bone level was lowered for
placement of prosthetic margin and reestablishment of the biologic
width

60. The biologic width, at treated sites, was reestablished to its original
vertical dimension by 6 months.
A consistent 3 mm gain of coronal structure was observed at the 3
and 6 month examinations

61. Orthodontic extrusion can be performed in two ways
Slow
By applying low orthodontic force, the tooth is erupted slowly, bringing the
alveolar bone, and gingival tissue along with it. The tooth is extruded until the
bone level has been carried coronal to the ideal level by the amount that needs to
be removed surgically to correct the biologic width violation. The tooth is
stabilized in this position and then treated with surgery to correct the bone and
gingival tissue levels.
Rapid
The tooth is erupted the desired amount over several weeks (with supracrestal
fibrotomy performed weekly in an effort to prevent the tissue and bone from
following the tooth). Then the tooth is stabilized for atleast 12 weeks prior to
surgical correction.
ORTHODONTIC TECHNIQUES

62. Indication:
Crown lengthening at sites where removal of attachment and bone
form adjacent teeth must be avoided.
The forced eruption technique can also be used as means of
reducing pocket depth at sites with angular bony defects.
Contraindication:
The forced eruption technique requires the use of fixed
orthodontic appliances.
Thus, in patients who have only a few teeth remaining, an
alternative approach for crown lengthening has to be selected.

63. If fibrotomy is performed during the forced tooth eruption procedure the
crestal bone and the gingival margin are retained at their pretreatment location
and the tooth-gingiva interface at adjacent teeth is unaltered.
Fibrotomy is performed by the use of a scalpel at 7 to 10 day intervals during
the forced eruption to sever the supracrestal connective tissue fibers, thereby
preventing the crestal bone from following the root in coronal direction.
Indication: Crown lengthening at sites where it is important to maintain
unchanged the location of the gingival margin at adjacent teeth.
Contraindication: Fibrotomy should not be used at teeth associated with
angular bone defects, ectopically erupting tooth.
FORCED TOOTH ERUPTION WITH
FIBROTOMY

65. Technique: If fibrotomy is performed during the forced tooth eruption
procedure the crestal bone and the gingival margin are retained at their
pretreatment location and the tooth-gingiva interface at adjacent teeth is
unaltered.
Fibrotomy is performed by the use of a scalpel at 7 to 10 day intervals
during the forced eruption to sever the supracrestal connective tissue
fibers, thereby preventing the crestal bone from following the root in
coronal direction.

66. Heithersay and Ingber (1973) were the first to suggest the use of
“forced eruption” to treat “non-restorable” or previously
“hopeless” teeth.
According to Starr, there are two concepts of forced
eruption:
1. Forced eruption with minimal osseous resection, and
2. forced eruption combined with fiberotomy.
Frank et al.(1997) described forced eruption of multiple teeth.
Since then, different clinicians have used various techniques to
extrude teeth using removable devices or fixed brackets.

67.  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.
HEALING AFTER CROWN
LENGTHENING

68.  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.

69. Shobha et al. (2010)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.

70. As with any procedure, the patient needs to be informed of any
potential complications such as possible poor aesthetics due to
 ‘black triangles’,
 root hypersensitivity,
 root resorption and
 transient mobility of the teeth.
COMPLICATIONS AFTER CROWN
LENGTHENING

71. The progression of periodontal destruction is generally
considered to be chronic in nature and slowly progressing.
However, under certain circumstances, disease progression may
be more aggressive, resulting in severe bone and attachment loss
at an early age.
BIOLOGIC WIDTH IN CHRONIC
PERIODONTITIS

72. One of the first changes of periodontitis is the migration of the
junctional epithelium along the root surface and its elongation,
resulting in formation of long junctional epithelium and a
gingival pocket.
The junctional epithelium needs a certain connective tissue
environment to establish whose specific characteristics have not
yet been defined but which, in healthy periodontium, is usually
found near the cervical portion of the tooth.

73. It has been believed for many years that the distance from the
most apical extent of subgingival calculus or plaque to the crest
of the alveolar bone remains generally constant, with mean values
of 1.94 to 1.97 mm.
An average value of 2.04 mm for the BW is considered to be the
norm for most patients and most teeth, although significant
variations can occur, especially in the length of the epithelial
attachment.
The supracrestal connective tissue attachment is an important,
but variable, component of the periodontal support that may
provide periodontal stability to teeth that lack alveolar bone
support as well as providing an unusually large BW.

74. Studies of young adults with severe generalized periodontitis have
shown that the most coronal level of clinical attachment does not
always relate to the crest of the alveolar bone in a manner that is
consistent with previous measures of the BW.
But considerable variability has been shown to exist in the
dimension of the BW in cross-sectional studies of autopsy
materials with no overt periodontal pathology.
(Gargiulo et al. 1961)

75. M. John Novak et al.(2008)determined whether the dimensions
of the biologic width applied to subjects with severe, generalized,
chronic periodontitis meet the previously established dimensions
or not.
They concluded that:
The mean clinical biologic width in subjects with severe,
generalized, chronic periodontitis seemed to be significantly greater
than the histologic biologic width previously reported for subjects
not demonstrating significant periodontal pathology.

76. In addition, sites with shallow probing depths demonstrated the
greatest biologic width, suggesting that these sites may be at
increased risk for losing clinically significant attachment during
surgical procedures

77. gore et al.(2014) had done a study to evaluate variations in
biologic width both clinically and radiographically in patients of
chronic periodontitis before and after treatment and concluded
that:-
There is variation between the biologic width of healthy
periodontal subjects and that of patients with periodontitis.
As the disease progresses, biologic width decreases

78. The biologic width regains its original dimensions after periodontal
therapy:
In cases of shallow pockets (3-5 mm) treated with scaling and root
planing it takes 3 months.
In cases of moderate pockets (5-7mm) treated with scaling and root
planing and open flap debridement may take 6 months.

79. Comparison between clinical biologic width and
radiographic biologic width shows significant
difference patients with periodontitis.
This difference was not significant after treatment of
patients with shallow pockets with SRP.
This difference is significant after treatment of
patients with moderate pockets with open flap
debridement.

80. There is no significant variation in the biologic width of buccal and
lingual/palatal areas as well as mesial and distal areas of gingiva.
Biologic width can be calculated by clinical as well as the radiologic
methods

81. Gaddale, et al (2015) conducted study to determine clinical BW in
healthy subjects and patients with chronic generalized
periodontitis and to compare it with previously established
histologic dimensions of BW.
They concluded that:
The mean clinical BW in subjects with healthy periodontium and
subjects with chronic generalized periodontitis seemed to be
signicantly greater than the histologic BW previously reported for
subjects not demonstrating significant periodontal pathology. In
addition, sites with shallow PDs demonstrated the greatest BW,
suggesting that these sites may be at increased risk for losing
clinically signi cant attachment during surgical procedures.

82. Wallace and Tarnow (1995) stated that the biologic width also
occurs with implants and may contribute to some of the early
bone loss observed.
The biologic width theory seems attractive to explain the lack of
bone loss from the first surgery and the early bone loss seen
within the year after the second-stage abutment placement.
BIOLOGIC WIDTH AROUND
IMPLANTS

83. However, several facts are not in favor of accusing
biologic width for early crestal bone loss seen around
dental implants.
In a typical implant
gingival region, only
two of the eleven
gingival fibers and no
periodontal fibers are
present.

84. • These fibers do not insert into the implant body below the
abutment margin as they do into the cementum of natural
teeth.
• Hemidesmosomes help form a basal lamina-like structure on
the implant, which can act as a biological seal, which only
provides mechanical protection against tearing.
• Therefore although the biological seal can prevent the
migration of bacteria and endotoxins into the underlying bone,
it is unable to constitute a junctional epithelial attachment
component of biologic width similar to one found with natural
teeth.

85. The amount of early crestal bone loss therefore seems unlikely to
be solely the result of the remodelling of the hard and soft
tissues to establish a biological width below an abutment
connection.

86. • There are big differences concerning
the structure, the vascular supply,
the localization and the
circumferential shape of
• Biologic Width
around implants comparing to
teeth.
• These differences have great
clinical impact in achieving
aesthetic outcomes in implant

87. Teeth Implant
Structure The
connective
tissue around
teeth is
cellular, rich in
fibroblast.
Around implants, the
connective tissue has a
paucity of cells and is
composed primarily of
dense collagen fibers,
similar to scar tissue.
The direction of fibers
is parallel to the
implant surface.
The connective tissue
adheres rather than
attaches to the implant
surface.

88. Teeth Implant
Vascularity Highly vascular
The vascular
supply around
teeth is derived
from the
subperiosteal
vessels lateral to
the alveolar
process and
from the
periodontal
ligament.
Poorly vascular
The blood supply,
originates from
terminal branches
of larger vessels
from the bone
periosteum at the
implant site, but
the blood vessels
from the
periodontal
ligament are
missing.
A zone of
avascular
connective tissue
is directly
adjacent to the
implant surface.

89. Teeth Implant
Localization A striking difference - if
around teeth the connective
tissue fibers are
inserted into the dentin
coronal to the bone
(supracrestal) and provide
support for the
soft tissues surrounding teeth,
The Biologic Width around
implants forms apical
to the bone crest (subcrestal).
The depth is given by the final
position of the remodelled
bone: 2-3 mm apical to the
implant abutment interface in
two- piece implants.
Circuferential
morphology
The Biologic Width follows
scalloped morphology.
The Biologic Width around
implants follows the shape of the
implant platform.
The Biologic Width is impinged
deep subcrestally, and will be far
greater at proximal level than on
labial or palatal aspect,
generating a significantly
proximal bone loss.

90. Alves et al (2015) conducted a study in a dog model in which they performed
Platform switching abutment at crestal bone level
1)in the test group, all prosthetic procedures were carried out direct to multi-
base abutment without disconnecting it
2) in the control group, the multi- base abutment was connected/
disconnected five times during prosthetic procedures
They concluded:
Only buccal aBE-BC parameter presented statistically significant differences
between test and control groups.
Test group presented 0.57mm less recession than control group, being this
difference statistically significant between the two groups

91. Cochran et al(2014) Loaded implants with machined and roughened
(SLActive) collars in a dog model
They concluded that the connective tissue contact were not significantly
affected by the type of implants; but that the junctional epithelium and
biologic width dimensions were larger around the implants with the machined
collars. The amount of inflammation was not different between the two
implan ttypes. Slightly more bone formation and more mature collagen
formation were detected around the implants with the roughened collars
compared to the implants with machined collars.

92. Nevins et al(2010) used machined, laser microchannel surface
abutments in dog model
They concluded that compared with machine surfaces, the
presence of a 0.7 mm laser ablated micro-channeled zone was
associated with increased fibroblastic activity on the abutment-
grooved surface, resulting in a denser interlacing complex of
connective tissue fibers oriented perpendicular to the abutment
surface.

93. Judgar et al (2014) performed stdy in human model in which they Unloaded
one- and two-piece implant.
They concluded that:
After 4 months of healing, marginal bone loss, gaps, and fibrous tissue were
not detected around two types of implants. The biologic width dimension
ranged between 2.55 ± 0.16 and 3.26 ± 0.15 to one- and two-piece implants,
respectively. This difference was influenced by the connective tissue
attachment, while the dimensions of sulcus depth and junctional epithelium
were similar between two groups

94. The differences in these histologic features explain why the inter-
proximal papilla, which consistently fills the inter-dental space in
natural dentition, is difficult to duplicate surgically in the case of
adjacent implants.
Periodontal augmentation procedures that are predictably
successful in normal dentition may have an increased risk of
failure around implants, with the potential for a result worse than
the original defect.

95. Therefore, the preservation or augmentation of soft
tissue prior to implant placement is of paramount
importance to obtaining optimal gingival contours
surrounding the restoration.

96.  The goal of any restorative treatment must be to
restore the health of the tooth and the periodontium
for optimum health and function.
 The gingiva is very sensitive to any external insults.
 With the progress in the gingival management
techniques every restorative dentist must strive to do
the procedure without inflicting any damage to the
gingiva.
CONCLUSION

97. 1. Padbury Jr A, Eber R, Wang H-L. Interactions between the gingiva and
the margin of restorations. J Clin Periodontol 2003; 30: 379–385
2. Schmidt JC, Sahrmann P, Weiger R, Schmidlin PR, Walter C. Biologic
width dimensions – a systematic review. J Clin Periodontol 2013; 40: 493–
504.
3. Gaddale, et al.: Clinical biologic width in chronic generalized
periodontitisJournal of Indian Society of Periodontology - Vol 19, Issue
2, Mar-Apr 2015
4. Zeinab Rezaei Esfahrood Biologic Width around Dental Implants: An
Updated Review JDMT, Volume 5, Number 2, June 2016
5. Aruna Nautiyal et al., Esthetic Crown Lengthening Using Chu Esthetic
Gauges journal of Clinical and Diagnostic Research. 2016 Jan, Vol-10(1):
ZC51-ZC55
REFERENCES

98. 5. Sushama R Galgali, Gauri Gontiya Evaluation of parallel profile
radiography to determine dimensions of dentogingival unit Indian
Journal of Dental Research, 22(2), 2011
REFERENCES