by dr. Esraa Riad Albatrawy

1. BIOLOGICAL
WIDTH
BY: DR/ ESRAA RIAD

2. CONTENTS
Definition of biologic width
Importance
Categories
Significant factors related to biologic width
Evaluation of b. w. violation
Correction of b. w. violation
Ferrule effect
B. w. in implants
Conclusion
refrences

3. DEFINITION OF B.W.
• Biological width is defined as the combined width of connective
tissue and junctional epithelial attachment formed adjacent to a
tooth and superior to the crestal bone. (2.04mm in depth)
• the dimension of soft tissue which is attached to the portion of the
tooth coronal to the crest of alveolar bone. ( Gargiulo et al 1961)
• biological width was found to be 2.044 which represents:
1. a sulcus depth of 0.6mm ,
2. an epithelial attachment of 0.97mm
3. and connective tissue attachment of 1.07mm.
• Its dimensions are variable from tooth to tooth and also from one
surface to another.

4. IMPORTANCE
• Acts as a barrier and prevents penetration of microorganisms into
the periodontium.
• Maintenance of biologic width is essential to preserve the
periodontal health and to remove any irritation that may damage
the periodontium

5. CATEGORIES (3)
• categories of biological width based on
bone crest and the sulcus depth following
bone sounding measurements.

6. • Normal crest patients: The midfacial measurement is 3mm and the proximal measurement range from
3mm to 4.5mm . It occurs approximately 85% of the time. The gingival tissues tend to be stable in
patients.
• High crest patients: It occurs in approximately 2% of the time. There is one area where the crest is seen
more often, in a proximal surface adjacent to an edentulous site. In these patients, the mid- facial
measurement is less than 3mm.
• Low crest patients: It occurs approximately 13%of the time. The mid-facial measurement is greater than
3mm and the proximal measurement is greater than 4.5mm

7. SIGNIFICANT FACTORS ( HOW TO PRESERVE)
1-Restorative margin location
2-Margin nature
3-Displacement of gingival tissues
4-Crown contours and proximal contacts
5-Pontic design
6-Provisional restorations
7-Subgingival debris

8. HOW TO PRESERVE? (SIGNIFICANT FACTORS)
1-RESTORATIVE MARGIN LOCATION
• The location, fit and finish of restorative margins are critical factors in the maintenance of periodontal
health.
• So, a huge consideration and care should have performed during isolation and retraction (even with
digital impression techniques) besides tooth preparation to the biological width to ensure the
healthy standards and maintenance the normal values of the periodontium.

9. There are three options available for the placement of margins:
• supra gingival,
• equigingival
• and sub gingival.

10. 1. SUPRAGINGIVAL
It is better to place the finishing line supragingivally fore the
reasons:
1. Preparation of the tooth and finishing of the margin is easiest.
2.Easier duplication of the margins with impressions.
3. Fit and finish of the restoration and removal of excess material is easiest.
4. Verification of the marginal integrity of restoration is easiest.
5. The Supragingival margins are least irritating to the gingival tissues .

11. 2. EQUI-GINGIVAL MARGIN
It was thought that placement of equi-gingival
margins caused more plaque accumulation than
supragingival or sub gingival margin resulting in
gingival inflammation.
But today the restorative margins can be
esthetically blended with the tooth and finished to
provide a smooth,polished interface at the
gingival margin.

12. 3. SUBGINGIVAL MARGIN
subgingival restoration demonstrated more quantitative and qualitative changes in the micro flora, increased plaque index, gingival index, recession, pocket
depth and gingival fluid.
Indication:
Aesthetic areas
Subgingival caries
Dentinal hypersensitivity
Subgingival discoloration
Short clinical crown

13. GUIDE IN SUBGINGIVAL MARGIN PLACEMENT RELATED
TO SULCULAR DEPTH
• Finish line placement According to Ingber et al. 1977, at least 3mm space is required from
finish line to the crest of alveolar bone to adequate healing and definitive restoration on
tooth
• Rule 1: If probing depth for gingival sulcus is 1.5mm or less then finish line should be 0.5mm
below the gingiva
• Rule 2: If probing depth is more than 1.5mm then finish line is placed on half of its sulcus
depth.
• Rule 3: If more than 2mm, advised gingivectomy up to sulcus depth of 1.5mm then finish
line is placed according to rule 1.

14. WHICH BETTER?
• Most of the studies prove that supra-gingival margins are most congruent in
regard to periodontal health. Hence it should be positively considered in non
aesthetic zones.
• The equi-gingival finish line can be considered in aesthetic zones with care during
tooth preparation and appropriate maintenance.
• In unavoidable clinical conditions, subgingival finish line can be established but
without iatrogenic damage to periodontium and accurate treatment planning.

15. Despite of the
material, the
margin should be
smooth , rounded
with good finish
and polish
2-MARGIN NATURE

16. 3-DISPLACEMENT OF GINGIVAL TISSUES
(GINGIVAL RETRACTION)
Objectives of gingival retraction:
1. Create an access for the impression material to the area of the preparation that is located sub-
gingivally.
2. To provide enough thickness of the impression material at the area of the finishing line to prevent
distortion of the impression.
3. Providing the best possible condition for the impression material, fluid control.
4. Reduce fluid a mount in the sulcus that might cause void in the impression.

17. GINGIVAL RETRACTION TECHNIQUES:
1)) Mechanical.(plain Retraction
cord ,Retraction Crown, Copper
band or tube , Anatomic
compression caps, Matrices and
wedges, Rubber dam )
2) )) Chemo mechanical
(combination of mechanical and
chemical)
• a) )) Impregnated Retraction cord ,with
one of following; (« aluminum sulfate„«
epinephrine, « ferric sulfate, « zinc
chloride, « aluminum chloride )
• b) )) Displacement polymer & paste
(Cordless technique)
3) )) surgical ( Gingitage , Electro-
surgical, Laser).

18. DOUBLE (DUAL) CORD TECHNIQUE
• When 2 cords are need, it requires that about 1 mm of intact tooth structure remains between the
top of the initial cord and the preparation margin.
• First Cord is Thin, Remain during Impression while the Second Cord is thick. In this technique, a thin
cord is placed without overlap at the bottom of the gingival crevice.
• A second cord is placed on top to achieve lateral tissue displacement and removed immediately
before impression making, whereas the initial cord is left in place to help minimize seepage during
Impression,
• be careful not to exert excessive pressure on the tissues, which can damage the epithelial
attachment (Biological Width).

20. 4-CROWN CONTOURS AND
PROXIMAL CONTACTS
Periodontal
health and
clinical
crown
contour are
interrelated.
Over-contouring of restoration has to be avoided in every case.
Gradual and smooth curvatures should be included in crown contour so as to facilitate the rubbing and
function of the lips, cheeks, and tongue.
Contour of interproximal area should be self cleansing and patient should be able to clean them comfortably.
Height of subgingival contour facio-lingually should not be more than ½ of the thickness of the gingiva. This
protects the gingival crevice and helps in maintaining knifelike free gingival margin, with plaque control

21. 5-PROVISIONAL RESTORATIONS
• Three critical areas must be effectively managed to produce a favorable
biologic response to provisional restorations during the interval until the final
restorations are delivered.
1. The marginal fit,
2. crown contour,
3. surface finish of the restorations
• Temporary restorations that are improperly adapted at the margins, that are
over or under contoured, and that have rough or porous surfaces can result in
inflammation, overgrowth, or recession of gingival tissues.
• The outcome can be unpredictable; and unfavorable changes in the tissue
structures can compromise the success of the final restoration.

22. 6-SUBGINGIVAL DEBRIS
• An adverse periodontal response can be created if debris is left below the tissues during
restorative procedures.
• The source can be retraction cord, impression material, provisional material, or either
temporary or permanent cement
• The diagnosis of debris as the cause of gingival inflammation can be confirmed by
examining the sulcus surrounding the restoration with an explorer, removing any foreign
bodies, and then monitoring the tissue response.
• It may be necessary to provide tissue anesthesia for patient comfort during the procedure.

23. 7-HYPERSENSITIVITY TO
DENTAL MATERIALS
• Inflammatory gingival responses have been reported related to the use of nonprecious alloys
in dental restorations
• Typically, the responses have occurred to alloys containing nickel, although the frequency of
these occurrences is controversial
• Hypersensitivity responses to precious are extremely rare, and these alloys provide an easy
solution to the problems encountered with the nonprecious alloys.
• In clinical research, porcelain ,highly polished gold, and highly polished resin all show similar
plaque accumulation.
• Regardless of the restorative material selected, a smooth surface is essential on all materials
subgingivally.

24. 8-CEMENTATION
• Excess cement in subgingival spaces can be described as
an “artificial calculus” and may have a similar irritating effect
as a calcified calculus on periodontally involved teeth and
hence affecting the biologic width.

25. EVALUATION OF BIOLOGIC WIDTH VIOLATION
1-Clinical sign and symptoms
3-Radiographic evaluation
2-Bone sounding
 The biologic width has inter-personal and intra-personal variability.

26. 1. CLINICAL SIGNS AND SYMPTOMS OF BIOLOGIC WIDTH
VIOLATION
• The presence of discomfort during examination of restoration margins indicates
biologic width violation.
• The clinical signs and sequel of biologic width violation are:
1.Chronic progressive gingival inflammation around the restoration
2.Bleeding on probing
3.Localized gingival hyperplasia with minimal bone loss
4.Pocket formation
5.Gingival recession
6.Clinical attachment loss
7.Alveolar bone loss
• Invasion of restoration into biologic width initiates crestal bone resorption.
• This occurs to allow space for establishment of a minimum biologic width

27. 2-BONE SOUNDING
1. Measurements carried out with a calibrated periodontal probe.
2. Probe fitted tightly with a silicon rubber sliding 'stoper.’
3. Under local anesthesia the probe was placed in the corono-apical direction, held against the
tooth, and advanced apically so that the rubber stop would stay at the incisal edge with the probe
tip at the base of sulcus in parallel direction to the tooth axis.
4. This distance was assessed with Vernier calipers
5. The probe was then advanced further apically until osseous tissue (crestal bone)was felt, and this
distance was also recorded.
6. The difference of the two recorded measurements indicated the biological width
• If this distance is less than 2mm at one or more locations, a diagnosis of biological width violation
can be confirmed.
• This measurement must be performed on teeth with healthy gingiva and should be repeated on
more than one tooth to ensure accurate assessment and reduce individual and site variations.

29. 3- RADIOGRAPHIC EVALUATION
Radiographs are useful non-invasive tools in the
assessment of biological width encroachment.
Parallel profile radiographic (PPR) technique has been
introduced to measure the dimensions.
This technique is limited for anterior region and only for
labial surface in healthy teeth.

30. The most apical point of the gingival sulcus was
assessed by probing [Figure 1].
To highlight the soft tissue structures on the radiograph, the auxiliary elements used were
gutta percha and lead foil because of their opaque nature. After probing, gutta percha was cut
to the sulcus depth [Figure 2, 3],
The lead foil was cut appropriately [Figure 4]
and then positioned over the gingival surface,
aligned with the long axis of the tooth.
The paralleling device was placed in such a way that
the film was positioned on the lateral vestibule
When the patient fixes teeth on the bite block fig 5
The radiographs thus obtained were digitized using
a scanner fig 6. The images were imported to
Adobe Photoshop CS2.

31. THE FOLLOWING MEASUREMENTS CAN BE OBTAINED:
1-Distance between the bottom of the gingival sulcus
(apical end of gutta percha) and the bone crest - thus,
the length of the DGU
2-Thickness of labial soft tissue measured from the
palatal face of the lead plate to the root surface - thus,
the width of the DGU
The limitation of this technique is that it cannot be used
in posterior teeth and unhealthy periodontal tissues.

32. METHOD TO CORRECT BIOLOGIC WIDTH VIOLATION
BY CROWN LENGTHENING EITHER SURGICALLY OR ORTHO:
• 1. Surgical crown lengthening:
1. Gingivectomy
2. APF with osseous reduction
3. Surgical extrusion
• 2. Orthodontic procedure
1. Forced eruption ( slow orthodontic extrusion)
2. Forced eruption combined with fiberotomy (rapid orthodontic extrusion)

33. 1-GINGIVECTOMY
• It is the Excision of the gingiva.
• The incision should be beveled at approximately 45 degrees to
the tooth surface, and it should re-create the normal festooned
pattern of the gingiva.
• Indications :
1. Elimination of suprabony pockets if the pocket
wall is fibrous and firm
2. Elimination of gingival enlargements
• Contraindications
1.Access to bone required
2.Narrow zone of keratinized tissue
3.Patients with high postoperative risk of bleeding

34. • Advantages: ease and simplicity of the procedure, but it has the
• Disadvantages of more postoperative discomfort and an increased chance
of postoperative bleeding. It also sacrifices keratinized tissue and does not
allow for osseous recontouring.
• Types (how to perform)
1.Surgical gingivectomy
2.Laser gingivectomy
3.Chemosurgery gingivectomy
4.Electrosurgical gingivectomy

37. 2-APF WITH OSSEOUS REDUCTION
It is the most common procedure for clinical crown lengthening.
It is done in inadequate zone of attached gingiva and biologic width
less than 3 mm.
Dis adv: Detailed evaluation should be done before carrying out
osseous reduction as it compromises periodontal support of the
tooth, causes furcation involvement, poor crown-to root ratio and
gingival recession.
It should not be done during surgical crown lengthening of a single
tooth in the esthetic zone. In such cases, forced eruption should be
considered to prevent negative architecture.

42. 3-SURGICAL EXTRUSION
Fig. Surgical extrusion of tooth 1.2 with insufficient ferrule effect (a,b). Tooth was extracted
with an atraumatic method (c) and then reimplanted and splinted, waiting for healing (d–f).
Fig. Prosthetic rehabilitation.

43.  ORTHODONTIC PROCEDURES:
1-FORCED ERUPTION (SLOW ORTHODONTIC
EXTRUSION)
• In forced eruption, tooth is intentionally moved in a
coronal direction using gentle continuous force.
• The force stretches gingival and periodontal fibers
resulting in a coronal shift of gingiva and bone.
• Orthodontic extrusion requires an activation period of 4-6
weeks and 6-8 weeks retention period for tooth to become
stabilized in its new position.
• Additional surgical crown lengthening may be required
after forced eruption.
• The contraindications are inadequate crown-to-root ratio,
lack of occlusal clearance and periodontal complications.

45. 2-FORCED ERUPTION WITH FIBEROTOMY (RAPID
ORTHO EXTRUSION)
• Combination of orthodontic extrusion and severance of supra-crestal fibers,
termed supra-crestal fiberotomy is also used for crown lengthening.
• If fibrotomy is performed during the forced tooth eruption procedure, the crestal
bone, and the gingival margin are retrieved at their pretreatment location. Thus,
the tooth-gingiva interface at adjacent teeth is unaltered.
• Fibrotomy is performed once every 7-10 days during the phase of forced tooth
eruption

47. FERRULE EFFECT:
• A ferrule effect is defined as a ‘‘360 metal collar of the
crown surrounding the parallel walls of the dentine
extending coronal to the shoulder of the preparation. The
result is an elevation in resistance form of the crown from
the extension of dentinal tooth structure
• More precisely, parallel walls of dentin extending coronally
from the crown margin provide a ‘‘ferrule,’’ which after
being encircled by a crown provides a protective effect by
reducing stresses within a tooth called the ‘‘ferrule effect’’
• The presence of a 1.5- to 2-mm ferrule has a positive effect
on fracture resistance of endodontically treated teeth.
• If the clinical situation does not permit a circumferential
ferrule, an incomplete ferrule is considered a better option
than a complete lack of ferrule

49. IMPLANT AND B.W. AVERAGE OF B.W AROUND IMPLANT???

51. Summary video

52. CONCLUSION
the study of the periodontal-prosthodontic relationship is necessary for the ultimate success of the prostheses
In dentistry the area of biological width along with sulcus, around natural teeth or an implant is sometimes called Bermuda Triangle or
Devil’s Triangle.
Like the Bermuda triangle, this biological width area is the most violated and misused area in dentistry, by almost all the dentists
irrespective of their specialty.
Hence, this region should be evaluated prior to treatment planning of the restorative phase.
The maintenance of the normal structure of the biological tissues should be done and the concept of biologic width must be
followed at each procedure .
The periodontal health is an important key for the longevity of dental prostheses.

53. REFERENCES
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3. Preetha Selvan, Biologic Width and Its Importance in Dentistry, JMSCR Volume 2 Issue 5 May 2014
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