This document discusses the historical background and various methods of root biomodification, which involves chemically or mechanically modifying the root surface to promote periodontal regeneration. It describes how citric acid, tetracycline, fibronectin, and EDTA work to demineralize and detoxify the root surface in order to remove the smear layer and expose collagen fibers, making the surface more biocompatible and conducive to new attachment of periodontal tissues. Register and Burdick's 1975 technique using citric acid application for 2-3 minutes is outlined, along with modifications by Miller. The mechanisms and benefits of different agents are explained.

1. 1

2. • Deepu Mathews
• Associate Professor
• Malabar Dental College & Research Centre
• Manoor - Chekanoor Road, Manoor, Edappal, Kerala 679582
• https://macity.edu.in/

3. Introduction
The removal of bacterial deposits, arrest of periodontal
disease and regeneration of periodontal tissues that are
lost due to the disease process constitute the ideal and
main goal in periodontal therapy.
Thus, biocompatibility of root surface is of extreme
importance for achieving success of periodontal
therapy.
3

4. The oldest and most frequently attempted type of
periodontal regeneration, has involved chemical
modification of tooth surface.
The goal of this regeneration procedure is to
determine the alterations in the diseased root
surface that would create an appropriate and
hospitable surface for cell attachment and eventual
development of a fibre attachment.
4

5. Hence root biomodification procedures have been
introduced by using a variety of agents, in order to
detoxify, decontaminate and demineralize the root
surface, thereby removing the smear layer and
exposing the collagenous matrix of dentin and
cementum
5

6. HISTORICAL BACKGROUND
• In 1833, Marshall presented a case of pocket
eradication with “presumable clinical reattachment”
after the use of aromatic sulfuric acid.
• In the 1890s; Stewart described the use of acids in
conjunction with the mechanical removal of calculus
and cementum.
• Urist (1965) that suggested that dentin following
acid demineralization possessed inductive properties.
6

7. • Urist (1973) demonstrated in a series of
experiments that allogenic dentin matrix,
following partial or total demineralization with
O.6N HCl and transplanted in vivo in various
animal models, possessed the ability to induce
the formation of new bone or cementum.
7

8. • Register et al., in (1973) performed the first controlled
study on the use of acid on root surfaces. They
investigated whether new attachment,cementogenesis
and osteogenesis could be induced adjacent to tooth
roots demineralized in vivo.
Optimal cementogenesis and new connective tissue
attachment occurred when roots were demineralized
with citric acid, pH 1.0 for 2 -3min.
8

9. Root Biomodification
Root biomodification is a periodontal
regenerative procedure which involves
chemical or mechanical modification of
root surface.
9

10. Rationale :
 Root debriment generates a smear layer which contains micro-
organisms & toxins, that interfere in periodontal healing.
•Acid treatment causes demineralization of root planed dentin
•Exposes collagen fibrils of dentin matrix
•Help in adhesion of blood clot to root surface & favor migration of
fibroblasts
 Thus, the use of an agent to remove this smear layer and to
expose the collagen fibers is an important factor to obtain
biologically acceptable tooth surfaces.
10

11. Various Chemical Agents Used For
Root Biomodification :
 Citric Acid
 Tetracycline
 Fibronectin
 EDTA-(Ethylene Diamine Tetra Acetic Acid.)
 Sodium Deoxycholate
 Human Plasma Fraction
 Growth Factor
11

12.  Miscellaneous -
 Aqueous Ethyl Ether
 Lithium Aluminum Hydride
 Bile Salts
 Calcium Chelators
 Physical : Laser
12

13. Mechanical modification of root surface involves
scaling and root planing. This includes removal of
cementum removal of softened dentin, or the
smoothening of surface irregularities.However such
root modification may not completely remove
contaminated cementum particularly in apical
areas. A smear layer will inevitably cover the
instrumented surface.
13

14. I-Citric Acid
 Most common chemical agent used for root
biomodification.
 Citric Acid conditioning is based on the premise
that-
Demineralizies the root surface
Expose the collagen fibers
Forms a barrier against epithelial migration
Removal of smear layer formed by Instrumentation
14

15.  REGISTER & BURDICK (1976)
 Performed series of studies that showed-
Citric Acid at 1 PH, when applied for 2-3 minutes on
root surface causes:-
1) Surface demineralization
2)Induces cementogenesis & attachment of collagen
fibers.
He suggested that “It contains two or more groups in
its molecule which can combine with calcium and act
as chelating agent. It can participate in surface
exchange; with citric ions replacing phosphate ions in
the hydroxyapatite crystals. Citric acid acts on dentinal
hydroxyapatite by releasing hydrogen ions which
demineralizes the crystalline structure. 15

16. Mechanism of Action:
1. Antibacterial effect
2. Root detoxification
3. Exposure of root collagen
4. Removal of smear layer
5. Initial clot stabilization
6. Demineralization prior to cementogenesis
7. Enhanced fibroblasts growth
8. Attachment by direct linkage with or without
cementogenesis
9. Prevent epithelial migration along denuded root
surface
10. Accelerated healing and new cementum
attachment
16

17. Recommended Technique :
-By Register & Burdick (1975)
(i) Raise a mucoperiosteal flap
(ii)Throughly instrument the root surface-removing
calculus & underlining cementum.
(iii)Apply cotten pellets soaked in saturated solution of
citric acid.
*20-30% concentration PH1(61 gm of citric acid per
100 ml of distilled water is added to achieve pH of 1)
*Leave for 2-4 minutes
(iv) Remove pellets
*Irrigate root surface profusely with water.
(v) Replace the flap & suture it. 17

18. Technique of Register & Burdick:
- Modified by Miller (1983)
(i) Brushing application (Versus rubbing)
(ii)5 minutes application
(iii)Use of high concentration 50% and PH
2
18

19. Strerret et al (1989) :
 Found that- use of miller's technique on native
dentin removed the smear layer and opened the
dentinal tubules.
But did not expose collagen fibers.
Han's (1985)
 Have reported increase in new attachment.
Daly (1982)
 Immersed periodontally involved roots in citric
acid at PH1 followed rinsing in 0.85% Nacl for 1
minute. Found significant reduction in the
microflora in former.
19

20. • The use of citric acid has also been
recommended in conjunction with coverage of
denuded roots using free gingival grafts.
• The drawback of Citric acid conditioning is that
it creates an extremely acidic pH in the
surrounding tissues, which may result in
unfavorable wound healing responses and also
denaturation of the collagen.
20

21. II-Tetracyclines
 Broad spectrum antibiotics & effective against
periodontal pathogens.
 Have low PH in concentrated solution
Act as calcium chelator resulting in
deminerilazation.
 Action
(i) Enhances binding of matrix proteins
(ii)Stimulate the fibroblast attachment &
growth.
21

22. Widening of Dentinal tubules
after tetracycline application
Narrowed dentinal tubules
22

23. (iii)Suppress epithelial attachment & migration.
(iv) Removes amorphous layer & exposes dentinal tubules.
(v) Maintains anti-microbial activity for 14 days.
In vitro treatment of the dentin surfaces with tetracycline
increases binding of fibronectin,which in turn stimulates
fibroblast attachment and growth while suppressing epithelial
cell attachment and migration.It also removes an amorphous
surface layer and exposes the dentin tubules.
A human study showed a trend for greater connective tissue
attachment after tetracycline treatment of roots.
23

24. • Terranova et al. in 1986 have shown that the tetracycline
treatment of root surface suppresses laminin binding and
epithelial cell growth and attachment.
• Tetracycline treated dentin surfaces increased the binding of
fibronectin and stimulate fibroblast attachment and growth.
• It can also inhibit bone resorption by inhibiting osteoblast
and osteoclast derived MMPs, alteration of osteoclast
response to extracellular Ca++ concentration.
• Tetracycline also been found to enhance osteoblast activity,
increase collagen and bone formation when these processes
are suppressed during the disease.
24

25. III-Fibronectin
 High glycoprotein found on the surface of the
cells, in plasma, extracellular matrix and in
basement membrane.
 It is a glycoprotein required by fibroblasts to
attach to the root surfaces.
 Plays an important role in -
Promoting attachment of cell to one another to
extracellular matrix & collagen
25

26.  Possess therapeutic utility in promoting
connective tissue attachment for periodontal
regeneration.
 Biologic mediator that enhances the tissue
response in early phases of wound healing
prevents seperation of flap & favours haemostasis
& regeneration.
26

27. The use of fibronectin as a supplement to demineralization is,
therefore, strongly supported by the following factors :
1. The initial stage after demineralization and prior to new
attachment is fibrin formation and linkage.
2. It is the coronal growth of cells from the periodontal ligament
that is responsible for new attachment and fibronectin
stimulates this growth.
3. Favours the growth and attachment of fibroblasts over epithelial
cells to the root surface.
4. Speeds the linkage process by being Chemoattractive for
fibroblasts and stabilizing the clot between the exposed root
surface collagen and new fibers within the tissue.
27

28. • Smith et al., reported the effect of citric acid and
fibronectin on healing after periodontal flap surgery
in dogs. Results showed significant increase in new
connective tissue attachment in all surgical sites
where fibronectin had been applied.
• In another study 46 patients were evaluated after
treatment with citric acid and fibronectin and reported
significant gains in clinical attachment and probing
depth reduction.
• Caffesse et al. evaluated the effect of citric acid root
demineralization and fibronectin application on
periodontal flap surgery wound healing in beagle dogs
with naturally occuring periodontitis. They found that
the use of citric acid and fibronectin in combination with
flap procedure resulted in a greater gain of attachment 28

29. IV-EDTA (Ethylene Diamine Tetra acetic
Acid)
 It is a polyaminocarboxylic acid and a colourless,
water-soluble solid.
 EDTA is mainly synthesised from
ethylenediamine, formaldehyde sodium cyanide
 Chelating agent, for treating mercury and lead
poisoning
 Functions by forming a calcium chelate solution
with calcium ions.
 Softens Root surface.
 Removes smear layer.
 Effects partial demineralization to a depth of 20-
30 micro meter in 5 minutes. 29

30. • A set of studies have shown that root surface
demineralized by 18% EDTA facilitates the
attachment, migration and contraction of
fibroblasts.
• Results also showed that supersaturated (24%)
solution of EDTA was significantly more effective
than lower concentrations of EDTA with regard to
smear removing capacity.
30

31. Growth factors
• Growth factors are polypeptide molecules, released
by cells in the inflamed area, that regulate events in
wound healing.
• These are the proteins responsible for coordinating
these cellular repair processes. They can be
considered hormones that are not released into the
blood stream and have a very localized action.
31

32. • Currently, the factors which are believed to
contribute to periodontal regeneration include the
• Platelet Derived Growth Factor (PDGF)
• Insulin Like Growth Factor (IGF)
• Transforming Growth Factor (TGF)
• Epidermal Growth Factor (EGF)
• Fibroblast Growth Factor (FGF)
• Bone Morphogenetic Protein (BMP)
32

33. Platelet derived growth factor
• Platelet derived growth factor is composed of two
disulfide bonded polypeptide chains that are encoded by
two different genes (3 and 11), the PDGFA and PDGFB.
PDGF can exist as a heterodimer (PDGF-AB) or a
homodimer (PDGF-AA or PDGF-BB).
• Sources of PDGF include the alpha granules of platelet,
monocytes, macrophage,fibroblasts, endothelial cells, and
bone matrix. PDGF has been identified as a competence
growth factor and act synergistically with progression
growth factor such as the insulin like growth factor (IGF).
33

34. • Bartold examine the effect of PDGF-BB on human gingival
fibroblasts. He found that it significantly elevates hyaluronate
synthesis which correlates with early events seen in wound healing
and repair.
• Oates et al. found that TGF-b enhanced the response of the PDL
cells to the PDGF. Together, PDGF and TGF-b also stimulated
gingival fibroblast as measured by increased cell number
• In vivo study was done by Lynch et al., which demonstrated that a
topical application of PDGF and IGF-1 in beagles dog with
naturally occuring periodontitis resulted in substantial new bone
and cementum as well as the formation of the PDL
34

35. Transforming Growth Factor (TGF)
• TGF growth factor = sources included the platelets, osteoblast,
macrophages.
• TGF-b main storage site is bone, and it is activated when there
is a drop of pH as in during osteoclastic bone resorption.
• TGF-b also been reported to induce osteoblast chemotaxis and
stimulate extracellular matrix formation via the synthesis of
type I collagen, fibronectin, and osteonectin.
• In mature bone, it stimulate bone resorption by prostaglandin
dependent mechanism. In immature bone, it stimulate bone
proliferation and inhibit bone resorption by prostaglandin
independent mechanism. 35

36. • In vivo study of Lynch et al, which reported the topical
application of TGF-b to epidermal wound in pig and
caused inhibition of reepithelialization and increased
connective tissue volume, collagen synthesis, and
angiogenesis.
• Selvig et al. found no increase in bone regeneration
when a combination of TGF-b1, IGF-2, and basic FGF
topically applied to the surgically created defects in
dogs
36

37. Fibroblast growth factor (FGF)
• Fibroblast growth factor (FGF) are a family of polypeptides that
are potent mitogens and chemoattractants for endothelial cells as
well as for a variety of mesenchymal cells, including the
fibroblasts, osteoblasts, chondrocytes, smooth muscle cells and
skeletal myoblasts.
• Acidic FGF and Basic FGF. Basic FGF is 30 times more potent
• A characteristic unique to the FGFs is that they are potent
angiogenic factors critical to the wound healing and the
formation of granulation tissue.
37

38. • Terranova et al. reported that FGFs can stimulate
mitogenesis and chemotaxis in PDL cells.
• Feres-Filho and Trackman reported that basic FGF down-
regulated lysyl oxidase messenger RNA and enzyme
activity in a dose and time dependent manner.
• Lysyl oxidase is the limiting enzyme for collagen cross
linking to form collagen matrix, which is neccessary for
the differentiation of osteoblastic cells and bone
mineralization.
38

39. Insulin like growth factors (IGF)
• Insulin like growth factors (IGF) are a family of single chain
serum protein that shared similar amino sequences and
therefore similar spectrum of activities to that of insulin.
Two most common members in this group are the IFG-1 and
IFG-2
• Lynch et al. reported the combination of IGF-1 and PDGF,
resulted in 95% increase in epidermal thickness and a two
fold increase in the width of the newly formed connective
tissue.
39

40. Epidermal growth factor (EGF)
• Epidermal growth factor (EGF), is structurally related
to TGF-a and possess similar property. Its major source
are urine and salivary gland. In vitro, EGF stimulates
DNA synthesis and cell growth of epithelial cells
endothelial and mesodermal origin.
• Studies done in vitro has reported of EGF significantly
enhance reepithelialization and wound healing in term
of fibroblast proliferatoin and angiogenesis.
40

41. Bone Morphogenetic Protein (BMP)
• In 1965 Marshall and Urist demonstrated
that cellular events associated with
embryonic development could be
reproduced in other sites
• In late 1960’s and 1970’s – dentin contains
BMP’s
41

42. 42

43. Tissucol
• A fibrin — fibronectin sealing system (FFSS)
has been commercially available (Tissucol —
Tisseel) in Europe since 1975.
• It is a human plasma cryoprecipitate, which
consists of highly concentrated fibrinogen,
fibronectin,factor XIII, platelet — derived
growth factor (PDGF antiplasmins and
plasminogen. Aprotinin (bovine antiplasmin),
thrombin and calcium chloride are added
43

44. Enamel Matrix Protein (EMP)
• It is based on the biologic concept that the application
of Enamel Matrix Protein (amelogenins) may promote
periodontal regeneration as it mimics events that take
place during the development of periodontal tissues
• In a clinical study long term effect of Enamel Matrix
Protein treatment as an adjunct to modified Widman
flap surgery vs modified Widman flap plus a
placebo was assessed. The results in the EMP group
were better, as shown by a gain in the clinical
attachment level, probing depth reduction and
restoration of bone radiographically
44

45. • Microscopic examination after four months
revealed formation of new acellular cementum, new
PDL with inserting and functionally oriented
collagen fibers, and associated alveolar bone..
45

46. Emdogain
• It is a resorbable, implantable material that consists of
enamel matrix proteins extracted from developing
embryonic enamel of porcine origin supplied in sterile form.
• Emdogain contains a protein preparation that mimics the
matrix proteins that induce cementogenesis. During root
development, the Hertwig’s epithelial sheath deposits
enamel matrix proteins on the newly formed root dentin
surface. These proteins stimulate the differentiation of
surrounding mesenchymal cells into cementoblasts, which
form acellular cementum
46

47. • The major constituents arc amelogenins. Other proteins
identified include ameloblastin and enamelin. It uses
propylene glycol alginate (PGA) as a carrier.
• EMD is absorbed into the hydroxyapatite and collagen fibers
of the root surface, where it induces cementum formation
followed by periodontal regeneration.
• Emdogain has two presentation forms: One is in liquid and
powder form, in 2 separate bottles containing the vehicle and
the protein powder and the other is in the form of gel in
syringe. The material is stored in the refrigerator, at 2-8°C. It
should be used in no more than 2 hours from opening,
because it gelifies and hardens.
47

48. The technique by Mellonig
1. Raise a mucoperiosteal flap
2. Remove all granulation tissue and tissue tags, exposing
the underlying bone, and remove all root deposits by
hand, ultrasonic scaling, or both.
3. Completely control bleeding within the defect.
4. Demineralize the root surface with citric acid pH 1, or
preferably with 24% ethylene diamine tetracetic
acid(EDTA Biora) pH 6.7 for 15 seconds. This removes
the smear layer and facilitates adherence of the Emdogain. 48

49. 5. Rinse the wound with saline and apply the gel to fully cover
the exposed root surface. Avoid contamination with blood or
saliva.
6. Close the wound with sutures. Perfect abutment of the flaps is
necessary; if this cannot be obtained, correct the scalloping of
the gingival margin or perform a slight osteoplasty. Although
placement of the dressing is optional, it may protect the wound.
49

50. Laminin
• Laminin is a glycoprotein of high molecular
weight. It is capable of adhering to various
substrates. Laminin promotes gingival epithelial
and fibroblast chemotaxis. It also promotes
epithelial cell adhesion and growth to
tetracycline and glycoprotein conditioned
surfaces.
50

51. V- Sodium Deoxycholate & Human
Plasma Fraction
 These agents dissociate endotoxin into
subunits & detoxify the diseased root surfaces.
 Human - Plasma fraction- contains fibronectin
Increases connective tissue attachment.
Content - 69% alpha1 & alpha2 globulins
10% beta globulin
20% gamma globulin
51

52. VI- Miscellaneous
Aqueous Ethyl Ether
 Used to extract endotoxin
Lithium Aluminium Hydride
 Can cleave ester linkage in endotoxin.
Bile Salts
 Dislocate endotoxin into sub units which
reaggrate upon removal.
52

53. Laser
• Misra et al., showed that CO laser produced surface
charring and carbonization, and were totally ineffective
in exposing the dentinal tubules.
• The CO laser, when used with high-energy output,
especially in a continuous wave mode, is not appropriate
for root surface debridement due to major thermal side-
effects, such as carbonization.
• In vivo study by Liu et al., showed no additional benefit
when laser treatment was used secondary to traditional
SRP therapy
53

54. • Results from in vitro studies with Nd:YAG
laser have shown its efficacy in removing the
smear layer and inactivating the endotoxin
in the superficial layer of the root
surfaces.
• In vitro studies with Er:YAG laser have
shown its efficacy in removing the smear
layer.
54

55. Limitation of Chemical Substances
 May give rise to secondary endodontic
involvement via dentinal tubules.
 Depth of action is not controlled.
 Increased size of dentinal tubules
More penetration of micro-organism
may cause root caries.
 Chemicals may infavourably alter the
morophology of collagen.
55

56. COMPLICATION
 New attachment with regeneration is the
ideal outcome of the therapy.
 However, certain complication may be seen
(1) Healing with a long junctional epithelium.
(2) Ankylosis and resultant root resorption
(3) Recurrence of the pocket.
(4) Combination of above
56

57. CONCLUSION
• The use of root biomodification is divided into two different schools
of thought. Some authors favours it while others don’t.
• It is well established that the periodontally diseased root surface
does not favour regeneration of the periodontium due to its surface
characteristics.
• The in vivo and in vitro studies clearly indicate a greater potential
for cell and fiber attachment to demineralized root surfaces.
• However evidence does not support the use of citric acid,
tetracycline and EDTA to reduce probing depth or enhance clinical
attachment levels. They may have a role in removal of smear layer
and detoxification but this too has been proved only in in-vitro
and animal studies .
• The best method for ascertaining the clinical efficacy of acid-treated
root regeneration would be to conduct a randomized clinical trial
with sufficient statistical power.
57

58. REFERENCES
 Periodontology 2000
 Journal of clinical periodontology
 Text book of clinical periodontology
-Carranza & Newman
 Textbook of clinical periodontology and
implantology-Jan Lindhe
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