The future of dentistry and periodontics lies in regeneration. The goals of periodontal therapy lies in not only the arrest of periodontal disease progression but also regeneration of the lost periodontal structures. This presentation provides a review of the current understanding of the regeneration of the periodontium and the procedures involved to restore the periodontal tissues around the teeth.

3. Contents
• Goals of periodontal regenerative surgery
• Melchers concept
• Indications
• Evaluation of periodontal regeneration
• Objectives of periodontal regeneration
• Requirements for predictable regeneration
• Periodontal Regeneration can be achieved by:
• Guided Tissue Regeneration (GTR)
• Guided Bone Regeneration (GBR)
• Bone Replacement Grafts
• Biologic mediators
• Combined techniques

4. Goals of periodontal surgery

5. To reduce or eliminate gingival inflammation
caused by bacterial plaque and its byproducts
To correct anatomic defects caused by the
disease process.

6. The goal of regenerative periodontal therapy
is to reconstruct what has been destroyed by
periodontitis.

7. The goal of regenerative periodontal therapy
is to histologically regenerate lost alveolar
bone, periodontal ligament and cementum
over a previously diseased root surface

8. Melchers concept (1976)
The type of cell that repopulates
the root surface after
periodontal surgery, determines
the nature of the attachment

9. After surgery the root surface may be repopulated
by four different cell types:
Epithelial cells
Cells derived
from the
gingival
connective
tissue
Cells derived
from bone
Cells derived
from the
periodontal
ligament

10. Epithelial
cell leads to
formation of-
LONG
EPITHELIAL
ATTACHMENT

11. Cells derived from
the gingival
connective tissue
leads to formation of-
CONNECTIVE
ATTACHMENT WITH
RADICULAR
RESORPTION

12. Cells derived
from bone leads
to
ANKYLOSIS WITH
RADICULAR
RESORPTION

13. Cells derived from
the periodontal
ligament leads to
formation of-
PARTIAL
PERIODONTAL
REGENERATION

14. Melchers concept (1976)
He further added that surgical
procedures should be designed such
that both periodontal ligament and
bone be allowed to migrate
coronally, that can regenerate and
maintain the periodontium

15. Indications Of Regenerative Therapy
Deep intraosseous
defects
Tooth retention
Support for
critical teeth Aesthetics

16. Indications
Bone defects
associated with
aggressive
periodontitis
Furcation defects

17. Evaluation of periodontal regeneration
Clinical Radiographic
Surgical
re- entry
Histological
evaluation
(Best
evaluation)

18. Objectives of periodontal regeneration
Pocket reduction
and Clinical
attachment gain
Bone fill of the
osseous defect
Regeneration of
new cementum,
PDL, and bone as
determined by
histologic analysis.
To obtain healthy
maintainable
environment

19. Requirements for predictable regeneration
Undisturbed
Healing
Wound Stability Space Provision
Thorough Root
Planing
Preparation of
Osseous Defects
For New
Attachment

20. Periodontal Regeneration can be
achieved by

21. 1. Non-Bone Graft – Associated
Procedures
Removal of Junctional
Epithelium
Impeding or slowing
the migration of
Junctional
epithelium
Root biomodification

22. 2. Graft – Associated Procedures
Guided Tissue
Regeneration
Bone Grafts
Biologic mediators
(growth factors) &
enamel matrix
proteins
Combination
techniques

23. Non-Bone Graft
– Associated
Procedures

24. Removal of Junctional Epithelium
Can be achieved by curettage, chemical agents and
surgical methods.
Curettage being closed procedure not reliable.
Chemical agents - depth of penetration can not be
controlled, so not used nowadays.

25. Removal of Junctional Epithelium
Surgical methods: Gingivectomy was used, but not
indicated now.
Modified Widman flap is indicated as it removes
pocket epithelium and provide knife edge margins.
This technique is used to elevate flap for better
exposure of underlying area.

26. Impeding or slowing the migration of
Junctional epithelium
Coronally advanced flap: increases distance between
epithelial wound edge and underlying healing area
Principle of this flap is based on the fact that
epithelium from excised margin proliferate rapidly
downwards, thus impeding regeneration from bone
and periodontal ligament.

27. Impeding or slowing the migration of
Junctional epithelium
Coronally advanced flap can be used with root
biomodification and grafting procedures
Particularly helpful in mandibular molar furcations

28. Root Biomodification
Root biomodification is a periodontal
regenerative procedure which involves
chemical modification of root surface

29. Rationale of Root Biomodification
Periodontitis induces
alterations on the root surface
like reduced collagen fiber
insertion, alterations in mineral
density or surface composition,
and root surface contamination
by bacteria and their
endotoxins.
Root debridement generates a
smear layer that contains
micro-organisms & toxins, that
interfere in periodontal
healing

30. Rationale of Root Biomodification
These agents remove
smear layer
Expose the collagen
fibers to obtain
biologically acceptable
tooth surfaces
Thus, it promotes linking
of biomolecules (eg-
extracellular matrix
proteins) to exposed
collagen in the root
surface

31. Agents used are
Citric acid
(Not used now
as pH=1)
EDTA
Tetracycline Fibronectin

32. Functions
Demineralizes the
root surface
Expose the
collagen fibers
Removal of
smear layer
formed by
instrumentation
Eliminates
endotoxins &
bacteria

33. Functions
Makes the
tubules appear
wider
Forms a barrier
against
epithelial
migration
Accelerated healing &
new cementum
formation.

34. Tetracycline: Broad Spectrum antibiotic
• Enhances binding of extracellular matrix proteins
• Stimulate fibroblast attachment & growth.
• Suppress epithelial migration.
• Removes smear layer & exposes dentinal tubules.
• Maintains anti-microbial activity for 14 days

35. Fibronectin: Glycoprotein required by
fibroblasts to attach to the root surfaces.
• Promotes attachment of cell to one another and to
extracellular matrix & collagen
• CHEMO ATTRACTANT for fibroblast & periodontal
ligament cells.
• enhances early phases of wound healing, prevents
separation of flap, favours haemostasis & regeneration.

36. EDTA:
• Chelating Agent
• Removes smear layer.
• Effects partial demineralization to a
depth of 20-30µ

37. Method of Application of Root
Biomodifier
• Raise a mucoperiosteal flap
• Instrumentation of the root surface.
• Apply cotton pledgets soaked in agent and keep there
for 2-5minutes,depending on the application time.
• Irrigate the root surface thoroughly with water

38. Graft –
Associated
Procedures

39. Guided Tissue Regeneration

40. Guided Tissue Regeneration
Guided tissue regeneration (GTR) is the method of
preventing the epithelial migration along the
cemental wall of the pocket while maintaining space
for clot stabilization.
The classical studies on GTR were done by Nyman,
Lindhe, Karring and Gottlow

41. Principle of GTR
Based on the principle that the periodontal
ligament cells have the potential to regenerate the
lost attachment apparatus of the tooth. Since
migratory rate of epithelium is more, so by placing
membrane over bone and periodontal ligament,
overlying gingival epithelium and connective
tissue are excluded, thus guiding periodontal
ligament and bone cells to form new attachment
apparatus at defect site.

42. Objectives of GTR
Maintain space in which regenerating tissues
may form.
Protect and stabilize blood clot.

43. Objectives of GTR
Promote cellular growth from periodontal
ligament.
Exclude gingival epithelium and connective
tissue which may interfere with regeneration.
Gain new clinical attachment

44. Indications of Guided Tissue
Regeneration (GTR)
Grade II and
Grade III
Furcation
Defects
Narrow 2-wall or
3-wall infrabony
defects
Ridge
deficiencies
augmentation
Root Recession
Coverage

45. Indications of Guided Tissue Regeneration
Sinus lift
procedures
Healing of
extraction
sockets.
Repair of
apicoectomy
defects

46. Contraindications of Guided Tissue
Regeneration
Poor oral
hygiene
Inadequate zone
of attached
gingiva

47. Barrier design criteria
47
Scantlebury, Gottlow and Hardwilk(1993) described these five criterias
TISSUE INTEGRATION
CELL OCCLUSIVITY
CLINICAL MANAGEABILITY
SPACE-MAKING
BIOCOMPATIBILITY

48. Tissue integration
The membrane outer surface should integrate
completely with full thickness flap to prevent
membrane exposure and bacterial infection
The membrane inner surface should allow the
blood clot under the membrane to be
stabilized.

49. Cell occlusion
Barrier membrane should be impermeable for overlying epithelial
cells; as these faster growing cells will populate the wound site
and form long junctional epithelium, thus inhibiting the
regeneration.
Clinically manageability
Should be cut, shaped easily with
good clinical handling

50. Space-provision & Biocompatibility
The membrane should provide adequate
space for the regenerating cells and should
not fall over the bone defect.
Should not cause any foreign body immune
response

51. Types of barrier membranes
Nonresorbable
membranes
•eg. Millipore,
PTFE, Rubber
dam barrier
membrane
Biodegradable/Resorbable
membranes
•eg. Collagen
membranes,
PLA, PGA910
51

52. Non resorbable membrane
The most common among these is
polytetrafluoroethylene (PTFE) membrane.
It is biocompatible, good stiffness that helps
maintaining space between membrane and bone defect;
and has shown good regenerative effects, but it has to
be removed after 3-6 weeks. 52

53. Resorbable GTR membranes fall into two
major categories:
Natural
• Collagen
• Duramater
• Cargile membrane
• Oxidized cellulose
• Laminar bone
• Periosteum
Synthetic
• Polyglycolic acid
& polylactic acid
• Polyurethane
membrane
53

54. Resorbable membranes
Elimination of second
surgery for barrier removal
Reduce operatory time
Reduced total cost
54

55. Some available Resorbable
membranes
Bioguide: A bilayer collagen membrane (porcine derived).
Most popular membrane
BioMend: Tendon collagen (bovine derived)
Atrisorb: Polylactic acid gel
55

56. Surgical procedure
Incisions
Defect
preparation
Placement of
suitable
membrane.
Suturing
Membrane
removal
(in case of
nonresorbable
membrane)
56

57. FACTORS AFFECTING OUTCOME OF GTR
THERAPY
Oral hygiene Smoking
Diabetes
Mellitus
Root surface
preparation
Adequate
amount of
attached gingiva

58. FACTORS AFFECTING OUTCOME OF GTR
THERAPY
Resorbable membranes are
commonly used nowadays; but
tends to fall on bony defects,
leaving no space for bone
regeneration. Thus, greater
regenerative results when
membranes combined with
bone grafts

59. Guided Bone Regeneration (GBR)
Technique of bone regeneration that has evolved from guided tissue regeneration
(GTR)
GTR is used for regeneration of lost periodontium (root cementum, periodontal
ligament, and alveolar bone) while GBR is for the regeneration of supporting bone
In GBR procedure, cell-occlusive physical barrier is placed between the connective
tissue and the alveolar bone defect

60. Uses
GBR increase bone volume in the areas with bone resorption due to long
standing lost of tooth/teeth.
Implants placement is difficult in such areas due to bone resorption.
GBR procedure increases bone volume, thus facilitating implant placement
with long term stability.

61. Principles of guided bone regeneration
1. Cell exclusion
2. Tenting
3. Scaffolding
4. Stabilization
5. Framework
Wang et al 2006Wang et al 2001

62. Indications of Guided Bone Regeneration
(GBR)
Horizontal or
vertical alveolar
ridge
deficiencies
Dehiscence and
fenestrations
associated with
implants
Bone defects
associated with
failing implants
Residual bone
lesions

63. Indications of Guided Bone Regeneration
(GBR)
Repair of sinus
membrane
perforations.
Osseous fill
around
immediate
implants

64. Advantages of GBR/GTR with Bone
Grafting
Support the
membrane to avoid
membrane collapse
Act as a scaffold for
bone in growth or
stimulate bone in
growth from the
recipient site
Protect the
augmented volume
from resorption
Supply a mechanical
shield against
pressure from the
overlying soft
tissues

65. BONE REPLACEMENT GRAFTS

66. • New bone formed by live osteoblasts in the grafted material
Osteogenic
• Grafted material does not contribute to new bone formation
• Acts as a scaffold for bone formation that originates from
adjacent bone
Osteoconductive
• Bone formation is induced in the surrounding soft tissue
immediately adjacent to the grafted material by release of
growth factors or other stimulatory mediators
Osteoinductive

67. BONE GRAFTS (CLASSIFICATION)
Autogenous grafts
Transferred from one site to another in same individual
Harvested extraorally (iliac crest) or intraorally (mandibular symphysis)
Osteogenic graft
Allogeneic grafts
Between genetically dissimilar members of the same species
eg. Demineralized freeze dried bone (DFDBA): Osteoinductive
Freeze dried bone (FDBA): Osteoconductive

68. BONE GRAFTS
Xenogeneic grafts
Taken from a donor of another species
eg. Bovine Bio-Oss: osteoconductive
Non Bone Graft materials
Synthetic or inorganic materials that can be used as bone
substitutes.
eg Hydroxyapatite, β-tricalcium phosphate, polymers:
Osteoconductive

69. Graft Materials
Bone Graft None-Bone Grafts
Auto Graft
Intra Oral
Extra Oral
Osseous Coagulum
Bone Blend
Cancellous Bone marrow
Bone Swaging
Iliac Autografts
Allografts
Decalcified Freeze Dried Bone
Undecalcified Freeze Dried Bone
Xenograft
Bovine derived bone
replacement graft

70. NON BONE GRAFT MATERIALS
Sclera Cartilage Plaster of Paris Biomaterials
Calcium phosphate biomaterials
(TCP, HA)
Bioactive Glass
Coral- Derived Materials

71. AUTOGENOUS BONE GRAFTS
 Autogenous bone still remains gold standard of the bone
graft materials.
 Contains viable bone cells (osteoblasts) and thus yields
most predictable results.
 It can be cortical graft or cancellous graft

72.  A cortical graft is strong initially but weakens overtime before
regaining strength.
 Cancellous grafts tend to be weak initially due of their open
architecture but gain strength over a period of time.
 Cancellous grafts have the ability to revascularize sooner due
of their spongy architecture. This revascularization starts
around the fifth day.

73. Osseous Coagulum
Described and termed by R. Earl Robinson.
Sources
 Lingual Ridges of mandible
 Exostoses
 Edentulous ridges
 Bone distal to last tooth
 Bone removed during osteoplasty or ostectomy techniques

74. Method
 carbide bur # 6 or # 8 at speeds between 5000 and 30,000 rpm are
used to remove cortical bone. Small particles in the form of bone
dust is placed in a sterile dappen dish.
The mixture of bone dust and blood is used to fill the defect.
Small particle size increases its surface area for cellular and vascular
interaction.

75. Disadvantage
 Predictability is low
 Inability to get adequate material for large bone defects

76. Bone Blend
Sources include - extraction socket, exostosis, edentulous area
Bone is removed, triturated in the autoclaved capsule with pestle to plastic-
like mass that can be easily packed into bony defects.
Proposed to overcome the problems associated with osseous coagulum, but
lack of effectiveness is major drawback

77. Intraoral Cancellous Bone Marrow Transplants
Sources include - extraction socket, maxillary tuberosity, edentulous area
Maxillary tuberosity usually contains a good amount of cancellous bone, particularly when the third molars
are absent. After healing period of 8-12 weeks in extraction sockets, area is re-entered and bone is removed
from apical areas.
Lack of effectiveness is major drawback

78. Bone Swaging
Requires the existence of an edentulous area near the defect
The bone is pushed into defect area without fracturing it from its base.
Limitation of this Technique – Chances of fracture.

79. Disadvantage of auto grafts from intra-
oral sites
Amount of available graft material
Second surgical site created with their
harvest

80. BONE FROM EXTRAORAL SITES
In 1923, Hegedus pioneered the use of extraoral sites, with use
of tibia into periodontal osseous defects. Schallhorn and Hiatt in
1960s proposed the use of iliac crest.

81. Iliac Autografts
This fresh or preserved iliac cancellous
marrow has been extensively used by
orthopedic surgeons; in periodontal defects
and furcation areas

82. PROBLEMS ASSOCIATED WITH ITS USE (NOT
USED NOW IN PERIODONTAL DEFECTS)
Infection
Exfoliation
and
sequestration
Recurrence
of defects
Increased
cost
Difficulty in
procuring the
graft

83. Allograft
Derived from human
cortical bone within 12
hours of donor death
No need to create second
surgical site as required
for autografts
Antigenic potential of
allografts and xonografts
are suppressed by
radiation, freezing,
chemical treatments
during processing

84. Allograft: It is of two types
Freeze-dried
bone allograft
(FDBA)
• Osteoconductive
Demineralized
freeze-dried bone
allograft (DFDBA)
• Osteoinductive
• “Gold standard”
graft in
periodontal
regeneration84

85. Freeze dried bone allograft (FDBA)
Freeze-drying the
bone decreases
the antigenicity
of the allograft
Formation of
bone by
osteoconduction
Radiopaque as it
is not
demineralized

86. Demineralized freeze dried bone
allograft (DFDBA)
Demineralization in cold and
dilute HCl exposes bone
morphogenetic proteins (BMP’s)
BMPs are bone-inductive
proteins that induce bone
formation by differentiating
undifferentiated mesenchymal
cells into osteoblasts
It is both osteoinductive and
osteoconductive; better than
FDBA; efficacy equivalent to
autografts

87. Particle size
Particle size of range of
250 to 750um is
recommended for
periodontal bone grafting
procedures
A pore size in the range
of 100 to 200 um is
considered optimal for
endothelial and
fibroblastic in growth
Pore size is distance between
two graft particles. It is
important when considering new
bone growth.

88. Xenografts
Derived from other
species
Osteoconductive
Calf bone (Boplant), Kiel bone
(calf or ox bone), Anorganic
bone (ox bone) are few
xenografts that are not used
nowadays

89. Bovine derived bone replacement
graft- Bio-Oss (Osteohealth)
Organic part is eliminated leaving a
hydroxyapatite structure of cortical and
cancellous bone, similar to that of human bone
Act as osteoconductive scaffold that
enables clot stabilization,
revascularization and osteogenesis with
subsequent migration of osteoblasts.

90. Bovine derived bone replacement
graft- Pepgen P-15 (Dentsply)
Recently Yukna et al combines Bio-Oss with a
cell binding polypeptide that is a synthetic
clone of the 15 amino acid sequence of type I
collagen.
Enhanced bone regenerative potential
as compared to Bio-Oss

91. Nonbone Graft Materials
Sclera, Cartilage and Plaster of Paris are no
longer in use for periodontal regeneration
Calcium phosphate biomaterials,
Bioactive glass, Coral derived materials
are used

92. Nonbone Graft Materials
Osteoconductive Unlimited quantity
No risk for disease
transmission (As it
is synthetic
material)
No additional
surgical site

93. Calcium phosphate biomaterials (Non-
antigenic, osteoconductive)
Hydroxyapatite
(HA)
•Nonresorbable
•Calcium to
phosphate ratio
is 1.67 (similar
to bone)
Tricalcium
phosphate (TCP)
• Partially resorbable
material
• Calcium to
phosphate ratio is
1.5 (is B-
whitlockite)
93

94. Bioactive Glass
Available as Perioglas with particle size 90-
170um; BioGran with particle size 300-355um
‘bioactive’means ability to bond to
bone and enhance bone-tissue
formation.

95. Bioactive Glass
It bonds directly to bone by
formation of a surface layer of
carbonated hydroxyapatite
(calcium phosphate-rich layer),
promotes adsorption of proteins
like chondroitin sulphate and
gylcosaminoglycans and attracts
osteoblasts to form bone.

96. Natural Coral & Coral derived porous
hydroxyapatite
Compatible, but slow resorbtion hindered
their regenerative results

97. BIOLOGIC MEDIATORS

98. Biologic Mediators
Bone grafting in periodontal defects have
shown regeneration in only apical aspect of
defect, that is not sufficient in quantity and
has low predictability
Thus, there arises need of growth
factors that accelerates cells in defect
area to proliferate and differentiate to
fibroblasts, cementoblasts and
osteoblasts

99. Biologic Mediators
Various biologic mediators like
Platelet-derived growth factor
(PDGF), Bone Morphogenetic Proteins
(BMPs), Enamel Matrix Derivatives,
Platelet-rich plasma (PRP) are being
used along with bone grafts to
enhance regeneration

100. Platelet-derived growth factor
(PDGF)
Recombinant human PDGF (rhPDGF)-BB has been combined with beta-tri calcium
phosphate (β-TCP) and available as GEM 21S. It has shown regeneration in
periodontal defects.
rhPDGF-BB has been approved by the FDA for periodontal regeneration
rhPDGF-BB has also been combined with DFDBA and has shown periodontal
regeneration histologically.

101. Bone morphogenetic proteins
Bone Morphogenetic Proteins (BMPs) is a unique group of proteins
within the Transforming Growth Factor beta (TGFb) superfamily.
BMPs demonstrate chemotactic properties and they
induce the differentiation of mesenchymal progenitor
cells into osteoblasts.

102. Bone morphogenetic proteins
BMP-2 has shown strongest bone producing property; BMP-7
(osteogenic protein -1) and BMP-3 (osteogenin) also stimulate
bone formation.
Bovine type I collagen combined with rhBMP-2 is
available commercially and cleared by FDA. Bovine
type I collagen allows slow release of BMP over a
period of 2-3 weeks, that slowly allows osteoblasts
differentiation over period of time forming new bone.

103. Enamel Matrix Derivatives
During tooth development, the inner cells of Hertwig’s epithelial root sheath
secrete enamel matrix proteins called amelogenin that eventually lead to
cementum formation, PDL and bone formation.
Enamel matrix protein derivatives obtained from developing porcine teeth
has been approved by the FDA and is marketed as Emdogain.
Histologic evidence of periodontal regeneration when Emdogain used with
autograft and allograft.

104. Platelet Rich Plasma (PRP)
Platelet Rich Plasma is first generation platlet concentrate. Blood
is mixed with sodium citrate dextrose (anticoagulant) in test tube
and centrifuged at 1300rpm for 10 minutes (slow spin). Second
centrifugation is done at 2000rpm for 20 minutes(hard spin)
Its in liquid form, not used nowadays due to life
threatening reactions by use of anticoagulant.

105. PROBLEMS ASSOCIATED WITH PRP
Requirement of
anticoagulant
Time period of
release of
growth factors
is less
Liquid nature of
PRP complicates
handling

106. Platelet Rich Fibrin
It is second generation platlet concentrate. Blood is placed in
test tube and centrifuged at 3000rpm for 10 minutes without use
of anticoagulant
In PRF 3-dimensional cross linked fibrin matrix act as
binding medium for platelets and WBC (that release
growth factors)

107. Platelet Rich Fibrin as membrane
As a thick matrix it stimulates migration of fibroblasts and
endothelial cells, resulting in angiogenesis; aids in clot
stabilization and prevent migration of non desirable cells into the
bony defect
Release growth factors like platelet derived growth
factors(PDGF), insulin like growth factors(IGF),
fibroblast growth factor(FGF), Transforming growth
factor(TGF), Vascular endothelial growth factor(VEGF)

108. Advantages of PRF
Used as
membrane (high
flexibility)
3D fibrin network
aids in release of
growth factors for
extended periods
Anticoagulant not
required
Can be used with
graft

109. Indications of PRF
Socket
preservation
Root coverage
Furcation
defects
Palatal wound
healing after
free gingival
graft

110. Indications of PRF
Ridge
augmentation
Horizontal
bone loss
Vertical bone
loss

111. Injectable Platelet Rich Fibrin (iPRF)
It is second generation platlet concentrate. Blood is placed in
test tube and centrifuged 700rpm for 3 minutes without use of
anticoagulant
More prolonged release of growth factors as compared
to PRF

112. Injectable Platelet Rich Fibrin (iPRF)
It is second generation platlet concentrate. Blood is placed in
test tube and centrifuged 700rpm for 3 minutes without use of
anticoagulant
Has high number of platelets, more prolonged release
of growth factors, higher fibroblast migration and
higher microbial activity as compared to PRF and PRP

113. Injectable Platelet Rich Fibrin (iPRF)
Its in liquid state, can be mixed with powered graft particles to
form sticky bone, that makes the graft particles clumped
together, more retentive, mouldable according to defect site with
higher number of growth factors.
iPRF has shown to increase gingival thickness

114. COMBINED TECHNIQUES

115. Combined Techniques
It is being proposed that combined use of
root conditioning agents, bone grafts,
biologic mediators, resorbable membrane
along with coronally advanced flaps can
result in an increased percentage of cases
with successful new attachment and
periodontal reconstruction.