Guided bone regeneration (GBR) is a surgical procedure that uses a membrane barrier to exclude soft tissue cells and promote bone regeneration in a defect site. GBR involves raising a mucoperiosteal flap, debriding the defect, placing grafting material to support the membrane, and covering it with a non-resorbable or resorbable membrane. Early studies using e-PTFE membranes demonstrated significantly more new bone formation compared to controls without membranes. GBR has been shown to successfully increase bone volume for dental implant placement and long-term stability.

1. GUIDED BONE REGENERATION

2.  Periodontal regeneration has been a field of research for
quite a long time now.
 Although, complete periodontal regeneration is still to be
achieved.
 Success in developing techniques which enhances
regeneration; root surfaces biomodification, guided
tissue regeneration, application of platelet rich plasma,
guided bone regeneration has been achieved.

3.  Guided bone regeneration (GBR) is a surgical procedure
involving the placement of a cell-occlusive physical
barrier between the connective tissue and the alveolar
bone defect.
 Guided bone regeneration (GBR) is a technique of bone
regeneration that has evolved from guided tissue
regeneration (GTR).
 The latter is a procedure performed for the regeneration
of lost periodontium (root cementum, periodontal
ligament, and alveolar bone) while GBR is for the
regeneration of supporting bone.

4.  The procedure of GBR is used to increase bone volume
in the areas with bone resorption due to long standing
lost of tooth/teeth.
 In long standing edentulous areas, usually there is bone
resorption which makes it difficult to place implants and
also affects long term stability.
 GBR procedure increases bone volume, thus facilitating
implant placement as well as long term stability.

6. PIONEER
 Dahlin et al. 1988, published the results of animal
experimentation on the healing of bone defects.
 Study: Bilaterally, a through-and-through defect was
surgically created in the ramus in 30 Sprague-Dawley
rats. On one side of the jaw, the defect was covered
with a porous polytetrafluoroethylene (PTFE)
membrane (Gore-Tex®). The other side served as the
control, without a membrane covering.
 Result: Statistical analysis of the healed sites
demonstrated a highly significant increase in bone
regeneration on the membrane side as compared to
the control.

7.  Dahlin et al. 1989, evaluated the principle of GTR to
generate bone at the exposed parts of titanium
implants.
 Study: 30 commercially pure 10-mm titanium implants
were placed in the tibia of 15 adult rabbits, each with
three to four exposed threads per implant. A PTFE
membrane was placed over the test fixtures, covering
the threads and 5 to 8 mm of the adjacent bone.
 Result: All exposed threads of the titanium implants
were covered with newly formed bone at a uniform
thickness, even as early as 6 weeks.

8. PRINCIPLES OF GUIDED BONE REGENERATION
 Wang et al 2001:
1. Cell exclusion
2. Tenting
3. Scaffolding
4. Stabillization
5. Framework

9. CELL EXCLUSION
 The cell population that hinders the regeneration
process such as gingival fibroblast or epithelial
cells should be prevented from reaching the
area of healing.
 To prevent this, various barrier membranes are
used.

10. TENTING
 The membrane is carefully fitted and applied in such a
manner that a space is created beneath the
membrane, completely isolating the defect to be
regenerated from the overlying soft tissue.
 It is important that the membrane be trimmed so that it
extends 2 to 3 mm beyond the margins of the defect
in all directions.
 The corners of the membrane should be also rounded
to prevent inadvertent flap perforation.

11. SCAFFOLDING
 The tented space initially becomes occupied by
a fibrin clot, which serves as a scaffold for the
in-growth of progenitor cells.
 It acts as a framework for cell migration and cell
proliferation.
 The progenitor cells here, migrate from adjacent
bone or bone marrow.

12. STABILIZATION
 The membrane must also protect the clot from
being disturbed by movement of the overlying flap
during healing.
 It is therefore often, but not always, fixed into
position with sutures, mini bone screws, or bone
tacks.
 Sometimes, the edges of the membrane are simply
tucked beneath the margins of the flaps at the time
of closure, providing stabilization.

13. FRAMEWORK
 In areas such as, dehiscence or fenestrations, the
membrane collapses and cannot maintain the space.
 In such areas, the membrane should be supported by
framework to prevent it from collapsing.
 Bone grafts such as, autografts, allografts or
xenografts may be placed which acts as framework,
preventing membrane collapse.
 Stiffer membranes such as titanium reinforced
membranes can also be used.

14. INDICATIONS FOR GBR
 Wang et al 2001:
1. Local alveolar ridge deficiencies (horizontal or
vertical).
2. Osseous fill around immediate implants.
3. Dehiscence and fenestrations associated with
implants.
4. Bone defects associated with failing implants.
5. Residual bone lesions.
6. To aid in repair of sinus membrane perforations.

15. CLINICAL PROCEDURE FOR GBR
 After achieving profound local anesthesia, an incision
is made in such a way that it is not placed directly over
the defect.
 This is done so that closure line should not be directly
over the defect but away from defect site.
 Vertical releasing incisions are given on indicated
sites.
 A full thickness flap is then reflected 2-3 m beyond the
margins of the defect.

16.  After this, an incision is made through the
periosteum to make it a partial thickness flap.
 The partial thickness flap is then raised using blunt
dissection.
 The defect is then debrided of all the granulation
tissue.
 The flap is trimmed and epithelium and tissue tags
are removed from the inner surface of the flap with
the help of sharp scissors.
 After this, the barrier membrane is taken out of its
packing and is trimmed in such a way that its
margins extend 2-3 mm beyond bony margins of
the augmented area.

17.  Small cortical perforations are then made with the help of round bur
in bone to induce bleeding points.
 The bone graft is then placed in the defects to support the tented
membrane.
 The membrane is then placed and adapted to the defect site.
 If the membrane is stable in its place, no attempt is made to fix it,
but if not stable then pins, bone screws, or tacks maybe needed to
assist stability.
 The surgical site is then closed with sutures.

19.  Romanos et al 2010, disscussed guidelines while
raising a mucoperisoteal flap for GBR procedure:
 The flap raised for GBR procedure has to be a
mucoperiosteal flap and it must be raised sufficiently to
achieve complete coverage of augmented sites.
 Flap should be raised over mucogingival junction in an
apical direction upto atleast 10 mm.
 To evaluate the tension of flap during coverage of
augmentation site, hold the flap in a coronal direction
with conventional dental forceps.

20.  If the flap is under tension while coverage an incision
is made through periosteum.
 The blade should cut tissue in a level apical to the
mucogingival junction.
 The flap is again pulled and checked for tension.
 To confirm appropriate tension free closure, make sure
that the buccal flap margins covers the lingual/palatal
site upto 3-5 mm.

21. BARRIER MEMBRANES USED IN GBR
 5 criteria to be considered ( Greenstein et al 1993,
Hardwick et al 1995) :
1. Biocompatibility,
2. Cell-occlusiveness,
3. Space making,
4. Tissue integration and
5. Clinical manageability.
 Various types of materials have been developed, which
can be grouped together as either non-resorbable or
resorbable membranes.

22. NON RESORBABLE MEMBRANES
 The first membranes used experimentally by Nyman’s
group in 1982, in their initial work were constructed
from Millipore® (cellulose acetate) filters.
 The first commercial membrane was produced
from Teflon® (e-PTFE).
 This membrane consisted of 2 parts: a collar
portion, having open pores to allow in-growth of
connective tissue and to prevent epithelial
migration; and an occlusive portion, preventing
the flap tissues from coming into contact with
the root surface

23.  Buser 1990, was one of the first to report successful
ridge augmentation with GBR in humans using an e-
PTFE membrane and tenting pins.
 Study: 12 patients, mucoperiosteal flap reflection,
cortical plate perforations, placement of titanium mini
screws to stabilize membrane.
 Result : Following a healing period of six to ten
months, the authors demonstrated an increase in bone
volume adequate to allow placement of dental
implants in nine of the twelve sites.
 The gain in new bone formation ranged from 1.5 to 5.5
mm.
 Biologic rationale: osteopromotion is highly predictable
for ridge enlargement or defect regeneration under the
prerequisite of complication-free healing.

24.  Becker et al 1994, conducted a clinical study that
determined the predictability for implants placed into
immediate extraction sockets and augmented with e-
PTFE barrier membranes.
 Study: A total of 49 implants were placed with e-PTFE
membranes.
 Result: The average bone formation for membrane-
retained sites was 4.8 mm, whereas the average bone
formation for sites in which the membranes were
prematurely removed (20) was 4 mm.
 Three implants were lost at abutment connection

25.  Fiorellini et al 2007, evaluated the percentage of bone-to-
implant contact following guided bone regeneration using e-
PTFE membranes and various bone fillers in a beagle dog
model.
 Study: Three months after bilateral extraction of the
mandibular premolars and first molars, rectangular, distal
extension defects that included the entire width of the ridge
buccolingually were surgically created in the alveolar
processes.
 All defects were covered with an e-PTFE membrane, and
several bone fillers were placed, in a randomized fashion,
under the membrane.
 Following an 8-month healing period, non submerged
titanium implants (36 total) were placed in regenerated

26.  Result: All sites demonstrated high percentages (50%
to 65%) of bone-to-implant contact, with no significant
differences across the various treatment groups.
 All tested bone fillers formed a complex that
supported and maintained the osseointegrated
implants in a healthy state, with no apparent signs of
peri-implantitis.
 Conclusion: Using a staged approach, this study
provided evidence that implants placed in entirely
regenerated bone can achieve and maintain
osseointegration, regardless of the type of bone fillers
used.

27. DISADVANTAGE OF USING NON RESORBABLE MEMBRANE IN GBR
 Membrane exposure caused by variable amounts of
flap sloughing during healing has been a frequent
post-surgical complication associated with the use of
non-resorbable membranes (Murphy et al 1995)
 Membrane exposure permits
between the oral environment
a communication
and newly forming
tissues, increasing the potential for infection and
decreasing the likelihood of regeneration.
 Non-resorbable membranes must be retrieved by
employing a second surgical procedure that can at
times be a tedious undertaking and can also disturb
healing (Wang et al 2001)

28. RESORBABLE MEMBRANES
 3 types of biologically resorbable membranes:
polyglactide (Resolute®),polyglactin
1. Polyglycoside synthetic copolymers: polylactic acid
910
(Guidor®),
(Vicryl®)
2. Collagen
3. Calcium sulfate (CalcigenOral®).
 Collagen membranes share in common with all
resorbable membranes the fact that they do not require a
second surgery for retrieval. This saves time and cost
and is also greatly appreciated by patients.
 Collagen is the principal component of connective tissue
and provides structural support for tissues throughout the

29. COLLAGEN MEMBRANE IN GBR PROCEDURE
 Sevor
resorbable
et al 1993,
collagen
evaluated
membrane
the usefulness of
for guided tissue
were surgically
regeneration. Buccal dehiscences
induced in 6 dog mandibles.
 Study: Twenty-four hydroxyapatite-coated and twenty-
four grit blasted implants were then placed in a
random pattern in both sides of the mandibles. A
resorbable collagen barrier membrane was placed
around one pair of implants on each side.
 Result: At 8 weeks, the mean defect fill was 80.29% in
the collagen membrane.

30.  Zitzmann et al 1997, compared a resorbable collagen
membrane (Bio-Gide®) to the conventional e-PTFE
material (Gore-Tex®) for guided bone regeneration in
situations involving exposed implant surfaces.
 Study: Over a 2-year period, 25 split-mouth patients
were treated randomly: one defect site was treated with
Bio-Gide® and the other defect site with Gore-Tex®; all
84 defects were filled with Bio-Oss® and covered with
the respective membrane.
 Result: Changes in defect surface for both types of
membranes were statistically significant. The mean
average percentage of bone fill was 92% for Bio-Gide®
and 78% for Gore-Tex® sites.

31.  Taguchi et al 2005, focused on histological changes
and cellular events in osteogenesis induced by GBR
with a collagenous membrane, Bio-Gide®.
 This membrane appears to have osteoconductivity,
resulting in a well-augmented alveolar ridge, which is
suitable for the subsequent placement of dental
implants.
 This material represents an excellent choice for GBR
by promoting osteoblastic activity.

32. GBR WITH BONE GRAFTING
 Bone filler materials may serve several purposes in
guided bone regeneration (GBR) procedures:
 Support the membrane to avoid membrane collapse
 Act as a scaffold for bone in growth from the recipient
site
 Stimulate bone in growth from the recipient site
 Supply a mechanical shield against pressure from the
overlying soft tissues
 Protect the augmented volume from resorption

34. INTRAORAL BONE HARVESTING.

35. INTRAORAL BONE HARVESTING TECHNIQUES

42. GBR WITH BONE GRAFT
 Proussaefs et al 2006, reported on three patients who underwent localized
alveolar ridge augmentation using block autografts harvested from the
mandibular tori.
 Study: Autogenous particulate bone graft was placed at the periphery of the
block. Resorbable collagen membrane was placed above the graft material.
Implant placement surgery followed at 6 to 16 months after bone grafting.
 Result: Laboratory measurements revealed 13% resorption at 6 months after
bone grafting while 0.53 mL of ridge augmentation was achieved 6 months after
bone grafting. Linear tomographs indicated 4.33 mm of

43.  Llambes et al 2007, performed vertical ridge
augmentation on 11 patients at the time of implant
placement.
 Study: The part of the implant out of bone was covered
with autogenous bone/graft, and a collagen membrane
was placed on top. Second-stage surgery was
performed 4 to 6 months later, and healing abutments
were placed.
 Result: Measurements revealed that the mean implant
out of bone was 3.5 mm at stage 1 and 0.5 mm at
stage 2. Mean bone gain was 3 mm. Histology from
one successful case showed new trabecular bone with

44.  The clinical outcome of horizontal ridge augmentation
using autogenous block grafts covered with an organic
bioabsorbable
von Arx and
bovine bone mineral (ABBM) and a
collagen membrane was analysed by
Buser in 2006.
 Study: In 42 patients with severe horizontal bone
atrophy, a staged approach was chosen for implant
placement following horizontal ridge augmentation. A
block graft was harvested from the symphysis or
retromolar area, and secured to the recipient site with
fixation screws. The block graft was subsequently
covered with ABBM and a collagen membrane.
 Result: The mean initial crest width measured 3.06 mm.
At re-entry, the mean width of the ridge was 7.66 mm,

45.  Hammerle et al 2008, Twelve patients in need of implant therapy participated in this
study.
 Study: Soft tissue flaps were carefully raised and blocks or particles of deproteinized
bovine bone mineral (DBBM/ Bio- Oss®) were placed in the defect area. A
collagenous membrane (Bio- Gide®) was applied to cover the DBBM and was fixed
to the surrounding bone using poly-lactic acid pins.
 Result: Before the regenerative procedure, the average crestal bone width was 3.2
mm and increased to 6.9 mm at the time of implant placement. This difference was
statistically significant.
 Conclusion: After a healing period of 9-10 months, the combination of DBBM and a
collagen membrane is an

46. FACTORS AFFECTING OUTCOME OF GUIDED BONE REGENERATION
 GTR and GBR procedures shares many factors in common; patient factors,
defect morphology, membrane properties.
 Hermann and Buser 1996, discussed 5 surgical factors that are required to
achieve predictable results with GBR procedure:
1. Use of appropriate membrane.
2. Achievement of primary soft tissue healing.
3. Maintenance of membrane protected space.
4. Adaptation and stabilization of membrane.
5. Long healing period.

47.  Wang and Boyapati 2006, described “PASS”
principles for prediction of bone regeneration:
1. Primary wound closure.
2. Angeogenesis
3. Space maintenance.
4. Stability of both blood clot and implant fixtures.

48.  Other factors:
 Incision location
 Tension in the flap

49. CONCLUSION
 GUIDED BONE REGENERATION (GBR) HAS BECOME AN IMPORTANT TOOL
IN THE IMPLANT SURGEON'S ARMAMENTARIUM TO DELIVER THE DESIRED
PROSTHETIC RESULT.
 THE CONCEPTS OF GBR ARE NOW WIDELY USED TO LOAD IMPLANTS IN
IMMEDIATE, DELAYED AND LATE EXTRACTION SOCKETS, IN TREATMENT
OF DEHISCENCE AND FENESTRATIONS IN PERI-IMPLANTITIS AND IN
RIDGE AUGMENTATION PROCEDURES SUCH AS HORIZONTAL AND
VERTICAL RIDGE AUGMENTATION.
With the present-day techniques, it ispossible to regenerate the
osseous tissue predictably when the principles and concepts of guided
bone regeneration are followed properly:

50.  The predictability of this procedure have been proved and established through
various experimental and clinical studies.
 Diagnosis, treatment planning, careful execution of the surgical treatment,
post-operative follow-up and appropriate implant loading are all important
factors in achieving success.
 Carefully designed clinical studies with sufficient statistical power would be
instrumental in elucidating the impact of site and patient related factors on the
effectiveness and predictability of the GBR treatment.