The supragingival margin has the least impact on the
The use of equigingival margins traditionally was not
desirable (though to be more plaque retentive and
esthetic prblemes after slightly recession)
From a periodontal view of point ,both supra and
equigingival margins are well tolerated
Ramifications of a biologic width
On the mesial surface of
the left central
incisor, bone has not been
lost, but gingival
On the distal surface of
the left central
incisor, bone loss has
occurred, and a normal
biologic width has been
Bone width (thin or thick?)
Gingiva (thin or fibrotic,flat or scalloped form?)
Biologic Width Evaluation
radiographs are not diagnostic because of tooth
A new radiographic technique called parallel profile
radiographic technique (PPR) is used to measure the
dimensions of the dental gingival unit (DGU). This
technique could measure both the length and the
thickness of the DGU with accuracy, as it is
simple, concise, non-invasive, and a reproducible
Biologic Width Evaluation
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.
The signs of biological width violation
Chronic progressive gingival inflammation around the
localized gingival hyperplasia with minimal bone loss,
clinical attachment loss
Gingival hyperplasia is most frequently found in
altered passive eruption and subgingivally placed
restoration margins. 
Jeffcoat and Howell (1980) demonstrated a link to the
severity of the overhang and the amount of
Overhangs were designated as large if they occupied
>51% of the interproximal space.
Small and medium overhangs (o20% and 20–50% of
the interproximal space,respectively) were not
associated with bone loss
Lang et al. (1983) investigated the specific aspects of
the local bacterial accumulation associated with
The placement of subgingival overhangs resulted in
changes in the associated microflora to that of one
resembling the flora observed in adult chronic
Increased proportions of Gram-negative anaerobic
rods, in particular black pigmented Bacteroides, were
Thus, overhangs not only increase plaque mass but
also increase the specific periodontal pathogens in the
Most overhanging restorations can be recontoured
without replacing the restoration, and this should be
considered a standard component of nonsurgical
Alveolar bone changes under overhanging
One study investigate changes in the trabecular
architecture of the alveolar bone beneath overhanging
restorations with bitewing radiographs in patients
having no radiographically visible vertical bone loss
It did not show statistically significant differences
between alveolar bone with and without overhanging
Variations in biologic width
Average is 2mm
But biologic width violations can occur in some
patients in whom the margins are located more than 2
mm above the alveolar bone leve
it varies from 0.75 to 4.3 mm in different individuals
specific biologic width assessment
To determine if the patient needs additional biologic
width, in excess of 2 mm
It can be identified for the individual patient by
probing to the bone level (referred to as “sounding to
bone”) and subtracting the sulcus depth from the
Kois  in 2000, proposed three categories of biological width based on the total
dimension of attachment and the sulcus depth following bone sounding
Normal crest patient
In the normal crest patients, the mid-facial measurement is 3 mm and the proximal
measurement ranges from 3 mm to 4.5 mm. Normal crest occurs approximately 85% of time. In
these cases gingiva tends to be stable for a long term.
High crest patient
This 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 mm.
Low crest patient
In the low crest patient group, the mid-facial measurement is greater than 3 mm and the
proximal measurement is greater than 4.5 mm. Low crest occurs approximately 13% of the time.
Traditionally a low crest patient has been described as more susceptible to recession secondary
to the placement of an intracrevicular crown margin. 
Correcting Biologic Width
In these situations the bone should be moved away
from the margin by the measured distance of the ideal
biologic width for that patient, with an additional 0.5
mm of bone removed as a safety zone.
Disadvantages(gingival recession , black triangles )
If the biologic width violation is on the interproximal
side or if the violation is across the facial surface and
the gingival tissue level is correct, orthodontic
extrusion is indicated
low orthodontic extrusion force and bringing the
alveolar bone and gingival tissue with it
rapid orthodontic extrusion where the tooth is
erupted to the desired amount over several weeks
Margin Placement Guidelines
the patient's existing sulcular depth be used as a
guideline in assessing the biologic width requirement
With shallow probing depths, future recession is
Deeper sulcular probing depths provide more
freedom in locating restoration margins
the deeper the gingival sulcus, the greater is the risk
of gingival recession
Margin Placement Guidelines
Rule 1: If the sulcus probes 1.5 mm or less, place the
restoration margin 0.5 mm below the gingival tissue crest
Rule 2: If the sulcus probes more than 1.5 mm, place the
margin half the depth of the sulcus below the tissue crest
Rule 3: If a sulcus greater than 2 mm is found, especially on
the facial aspect of the tooth, evaluate to see if a
gingivectomy could be performed to lengthen the teeth and
create a 1.5-mm sulcus. Then the patient can be treated
using Rule 1.
Clinical Procedures in Margin
The placement of supragingival or equigingival
margins is simple because it requires no tissue
But the subgingival margin placement is rather
So,prior the placement of margin subgingivally the
preparation should be extended to the free gingival
margin facially and interproximally.
The steps are as follows:
for protection from abrasion
For proper access
by gingival retraction cords
For rule one margin
1 st cord is placed 0.5mm below the prepared margin.
Protects the tissues
Creates the correct axial reduction
Establishes a desired subgingival level margin.
To create space and allow access for a final impression, it is
now necessary to pack a second retraction cord
2 st cord is displaced the first cord apically and sits bw the
For rule two margin
two larger-diameter cords are used to deflect the tissue
before extending the margin apically
a third cord is placed in preparation for the impression
electrosurgery is often required to remove
Electrosurgery tip being held parallel to the preparation
and resting on the previously placed retraction cord.
This removes a minimal amount of tissue
The tissue should be only be removed from
the inner surface of the sulcus
Three critical areas must be appropriate to maintain
the health and position of the gingival tissues:
surface finish of the interim restorations
poorly adapted margins, overcontoured or
undercontoured, and rough or porous surfaces can
recession of gingival tissues
Margins that are significantly open (several tenths of a
millimeter) are capable of harboring large numbers of
bacteria and may be responsible for the inflammatory
However, the quality of marginal finish and the
margin location relative to the attachment are much
more critical to the periodontium than the difference
between a 20-μm fit and a 100-μm fit
There is a relationship between overcontouring and
gingival inflammation, whereas undercontouring
produces no adverse periodontal effect
In areas of the mouth in which esthetic considerations
are not critical, a flatter contour is
Leaving debris below the tissue during restorative
procedures can create an adverse periodontal
The cause can be retraction cord, impression
material, provisional material, or either temporary or
The aim of this study was to investigate the association
between statin medication and periodontal infection in an
RESULTS: they found a weak negative association between
statin medication and periodontal infection among subjects
with dental plaque or gingival bleeding. Among subjects with
no gingival bleeding, statin medication was found to be
associated with an increased likelihood of having deepened
CONCLUSION: Statin medication appears to have an effect on
the periodontium that is dependent on the inflammatory
condition of the periodontium. More evidence is needed to
achieve a comprehensive understanding of the effects of
Hypersensitivity to Dental Materials
Inflammatory gingival responses have been reported related
to the use of nonprecious alloys in dental restorations.
Typically, alloys containing nickel.
responses to precious alloys are extremely rare
tissues respond more to the differences in surface roughness
of the material rather than to the composition of the
(The rougher the surface , the greater are the plaque
accumulation and gingival inflammation)
porcelain, highly polished gold, and highly polished resin
all show similar plaque accumulation.
the free gingival margin averages 3 mm above the bone
the tip of the papilla averages 4.5 to 5.0 mm above the
interproximal bone (but has the same biologic width)
Then the interproximal area will have a sulcus 1.0 to 1.5
mm deeper than that found on the facial surface.
Relationship between gingival embrasure volume
and papillary form
A, gingival embrasure of the teeth is excessively large the result of a tapered
tooth form. the shape of a normal papilla but rather has a blunted form and a
B,Because of the more closed embrasure form from the teeth in the papilla
completely fills the embrasure and has a deeper sulcus, averaging 2.5 to 3.0
Note that the ideal contact position is 3 mm coronal to the attachment
two causes of open gingival embrasures:
(1) because of bone loss
(2) the interproximal contact is located too high
coronally, there are two potential reasons:
a) If the root angulation of the teeth diverges, the
interproximal contact is moved coronally .
b) If the roots are parallel problem is probably related
to tooth shape, specifically an excessively tapered
Restorative dentistry can correct this problem by
moving the contact point to the tip of the papilla
Methods of altering gingival embrasure form
A, Typical open gingival embrasure caused by excessively tapered tooth form.
B, Common method employed by restorative dentists to correct the
embrasure, in which material is added supragingivally.(overhangs)
C, Correct method of closing the gingival embrasure, in which the margins of
the restoration are carried 1.0 to 1.5 mm below the tip of the papilla.
This patient has parallel roots, has recently completed orthodontic
therapy, and is unhappy with the open gingival embrasure between her central
incisors. An evaluation of papillary height reveals that all are at an equal level.
This can only mean that the open embrasure is the result of an overly tapered
A metal matrix band has been shaped to the desired
tooth form and placed 1.0 to 1.5 mm below the tip of the papilla.
Managing Gingival Embrasure Form for Patients
with Gingival Recession
In esthetic area it is necessary to carry the interproximal
contacts apically toward the papilla(restorations, tissuecolored ceramics )
In the posterior areas it is often impossible to carry the
proximal contacts to contact the tissue without creating large
overhangs on the restorations.the contact should be moved
far enough apically.
Although the sanitary pontic design provides the
easiest access for hygiene procedures, it is rarely
used because of its unesthetic form and a variable
acceptance of the open contour by patients
it is the ideal pontic form. It is created by forming a
receptor site in the edentulous ridge with a diamond
bur or by electrosurgery.
the depth of the receptor site depends on the esthetic
requirements of the pontic.
In highly esthetic areas such as the maxillary anterior
region, it is necessary to create a receptor area that is 1.0
to 1.5 mm below the tissue on the facial aspect.
This site can then be tapered to the height of the
palatal tissue to facilitate hygiene access from the
The receptor site has been created 1.0 to 1.5 mm apical to the free gingival
margin on the facial aspect.
On the palatal side, the pontic is tapered so that the receptor site is not
extended below tissue; this allows easier access for oral hygiene.
Note that when the receptor site is created, the bone must be a minimum of
2 mm from the most apical portion of the pontic.
Ovate pontics in less esthetic areas
it is possible to create a flattened receptor site in
which the pontic sits flush with the ridge. This
facilitates oral hygiene.
It is important to realize that certain soft tissue ridge
parameters must exist.
First, the ridge height needs to match the ideal height of
the interproximal papillae .
Second, the gingival margin height must also be at the
ideal level, or the pontic will appear too long.
Third, the ridge tissue must be facial to the ideal cervical
facial form of the pontic so that the pontic can emerge from
the tissue.(create illusion)
If any of these three areas is inadequate,ridge augmentation
RA procedures should be completed before, or in
conjunction with, fabricating an ovate pontic.
When constructing the final restorations, the
contours of the developed ovate pontic receptor site
can be conveyed to the laboratory by capturing a soft
tissue impression 4 to 6 weeks after the site has been
Ovate pontics after extraction
When a tooth is removed,The gingiva recedes 1.5 to
it can be prevented, By inserting the correct pontic
form 2.5 mm into the extraction site the day the tooth
At 4 weeks, the 2.5-mm extension can be reduced to a
1.0- to 1.5-mm extension to facilitate hygiene.
Patient who will have the right central incisor extracted
because of periodontal disease.
Because the patient desired to alter the esthetics of her remaining
anterior teeth, all the anterior teeth were prepared before
removal of the right central incisor
The key to maintenance of the interproximal papilla is that the
ovate pontic extend 2.5 mm into the extraction site on the day
Note that when the provisional restoration is seated on the day of
the extraction, 2.5 mm of the pontic extends upward into the
Nine months after placement of the provisional restoration. (At 4
weeks after placement, the pontic was shortened to extend
1.5 mm into the extraction site to facilitate oral hygiene.)
Ovate pontic site after removal of the provisional restoration and
before final impressions.
Two-year recall photograph of the final fixed prosthesis
full ridge-lap pontic
it is an outdated design that straddles the convexity
of the ridge buccolingually and creates an
undersurface that is entirely concave and cannot be
It is not recommended for use in any situation
modified ridge-lap pontic
it can be an acceptable design if inadequate ridge
exists to create an ovate pontic.
the pontic follows the convexity of the ridge on the
facial aspect but stops on the lingual crest of the ridge
the more open lingual form allows adequate access for
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Alveolar bone changes under overhanging restorations.
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4.Padbury Jr A, Eber R, Wang H-L. Interactions between the
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