wound healing after injury also its implications in dentistry. recent trends in wound dressing.

1. THE ABILITY TO HEAL IS INBUILT
IN OUR PHYSIOLOGY. WE ONLY
HELP BODY TO HEAL ITSELF AND
REMOVE ANY OBSTACLES IN THE
PATH OF HEALING.
1 / 69

2. Wound Healing and Repair
PRESENTED BY :-
ADITI CHANDEL
MDS 1ST YEAR
DEPARTMENT OF PERIODONTOLOGY
AND ORAL IMPLANTOLOGY 2/69
GUIDED BY :
DR. BALJEET SINGH
(PROFESSOR)
DEPARTMENT OF PERIODONTOLOGY
AND ORAL IMPLANTOLOGY

3. CONTENTS
• DEFINITION OF HEALING
• TYPES OF HEALING
• PHASES OF WOUND HEALING
• FACTORS INFLUENCING WOUND HEALING
• COMPLICATIONS OF WOUND HEALING
• FRACTURE HEALING
• PERIODONTOLOGY IMPLICATIONS
• HEALING IN IMPLANTS
• ENDODONTIC IMPLICATIONS
• HEALING AFTER EXTRACTION OF TOOTH
• HEALING OF REIMPLANTED TOOTH
• REMODELLING OF BONE IN ORTHODONTICS
• HEALING IN PATIENTS ON CHEMOTHERAPY/ RADIATION
THERAPY
• RECENT TRENDS IN MANAGEMENT OF WOUNDS
• CONCLUSION
• REFERENCES
3 / 69

4. HEALING
HEALING IS THE BODY RESPONSE TO INJURY IN AN ATTEMPT TO RESTORE
NORMAL STRUCTURE AND FUNCTION.
-
WOUND HEALING IS A PRIMARY SURVIVAL MECHANISM AND IS A PROTECTIVE
FUNCTION OF THE BODY THAT FOCUSES ON QUICK RECOVERY.
-WONG ET AL, 2013
HEALING
INVOLVES
REGENERATION REPAIR
4 / 69

5. 5 / 69
Robbins and cotran basic pathology 9th ed

6. REGENERATION
• WHEN HEALING TAKES PLACE BY PROLIFERATION OF PARENCHYMAL CELLS AND
IT USUALLY RESULTS IN COMPLETE RESTORATION OF THE ORIGINAL TISSUES
 PERIODONTAL REGENERATION is defined as the restoration of lost periodontium or
supporting tissues and includes formation of new alveolar bone, new cementum and new
periodontal ligament. Wang HL et al in 2005
THE FACTORS WHICH CONTROL HEALING AND REPAIR ARE COMPLEX AND THEY
INCLUDE THE PRODUCTION OF VARIETY OF GROWTH FACTORS:
EPIDERMAL GROWTH FACTORS
FIBROBLAST GROWTH FACTORS
ENDOTHELIAL GROWTH FACTOR
PLATELET DERIVED GROWTH FACTOR
TRANSFORMING GROWTH FACTOR- B
6 / 69
ESSENTIAL PATHOLOGY BY HARSHMOHAN, 4TH EDITION

7. TISSUE PROLIFERATION ACTIVITY
LABILE CELLS
STABLE CELLS
PERMANENT
CELLS
• CONTINUE TO MULTIPLY THROUGHOUT LIFE UNDER NORMAL
PHYSIOLOGIC CONDITIONS.
• E.G. SURFACE EPITHELIAL CELLS OF THE EPIDERMIS,
HAEMOPOIETIC CELLS OF BONE MARROW ETC.
• DECREASE OR LOSE THEIR ABILITY TO PROLIFERATE AFTER
ADOLESCENCE.
• CELLS FROM THESE TISSUE CAN UNDERGO RAPID DIVISION IN RESPONSE
TO STIMULI.
• E.G. PARENCHYMAL CELLS OF LIVER AND KIDNEY, BONE AND CARTILAGE
CELLS, FIBROBLASTS ETC.
• CANNOT UNDERGO MITOTIC DIVISION IN THE
POSTNATAL LIFE.
• E.G. NEURONS AND CARDIAC MUSCLE CELLS.
7 / 69
ESSENTIAL PATHOLOGY BY HARSHMOHAN, 4TH EDITION

8. CELL CYCLE
8 / 69

9. REPAIR
WHEN HEALING TAKES PLACE BY
PROLIFERATION OF CONNECTIVE TISSUE
ELEMENTS RESULTING IN FIBROSIS AND
SCARRING.
REPAIR IS THE REPLACEMENT OF INJURED
TISSUES BY THE FIBROUS TISSUE.
GRANULATIO
-N TISSUE
FORMATION
CONTRACTI-
-ON OF
WOUNDS
9 / 69
ROBBINS AND COTRAN, PATHOLOGIC BASIS OF DISEASE, 7TH ED.

10. 10 / 69

11.  Granulation Tissue formation
• GRANULATION TISSUE IS THE HALLMARK OF HEALING.
• GRANULATION TISSUE PROGRESSIVELY INVADES THE SITE OF
INJURY
• THE TERM GRANULATION TISSUE DERIVES ITS NAME FROM ITS
PINK, SOFT, GRANULAR APPEARANCE OF TISSUE.
PHASE OF
INFLAMMATION
PHASE OF
CLEARANCE
PHASE OF INGROWTH
OF GRANULATION
TISSUE
11 / 69
ROBBINS AND COTRAN, PATHOLOGIC BASIS OF DISEASE, 7TH ED.

12. 1: INFLAMMATION:
BLOOD CLOTS, EXUDATION OF PLASMA,
NEUTROPHILS, MONOCYTES WITHIN 24 HOURS.
2: CLEARANCE:
PROTEOLYTIC ENZYMES LIBERATED FROM
NEUTROHILS, AUTOLYTIC ENZYMES FROM DEAD TISSUE
CELLS, PHAGOCYTIC ACTIVITY OF MACROPHAGES.
3: INGROWTH OF GRANULATION TISSUE:
ANGIOGENESIS
FIBROGENESIS
12 / 69
ROBBINS AND COTRAN, PATHOLOGIC BASIS OF DISEASE, 7TH ED.

13. -FORMATION OF NEW BLOOD VESSELS AT THE SITE
OF INJURY BY PROLIFERATION OF ENDOTHELIAL
CELLS FROM MARGINS OF SEVERED BLOOD VESSELS.
-THE PROCESS OF ANGIOGENESIS IS STIMULATED
WITH PROTEOLYTIC DESTRUCTION OF BASEMENT
MEMBRANE.
-VARIOUS FACTORS INFLUENCING ANGIOGENESIS:
VASCULAR ENDOTHELIAL GROWTH FACTOR
(VEGF), PLATELET DERIVED GROWTH FACTOR,
TRANSFORMING GROWTH FACTOR-B, BASIC
FIBROBLAST GROWTH FACTOR (bFGF).
13 / 69
ANGIOGENESIS
ROBBINS AND COTRAN, PATHOLOGIC BASIS OF DISEASE, 7TH ED.

14. 14 / 69

15. IN THE NEWLY
FORMED BLOOD
VESSELS,
FIBROBLASTS
ORIGINATE FROM
FIBROCYTES AS WELL
AS THE MITOTIC
DIVISION OF
FIBROBLASTS.
A
COLLAGEN FIBRILS
BEGIN TO APPEAR BY
6TH DAY.
B
AS MATURATION
PROCEEDS, MORE
COLLAGEN IS FORMED
WHERE AS THE
NUMBER OF
FIBROBLASTS
DECREASES.
C
THERE IS FORMATION
OF INACTIVE
LOOKING SCAR
KNOWN AS
CICATRISATION
D
15 / 69
FIBROGENESIS
ROBBINS AND COTRAN, PATHOLOGIC BASIS OF DISEASE, 7TH ED.

16.  WOUND CONTRACTION
• IT STARTS AFTER 2-3 DAYS AND THE PROCESS IS COMPLETED BY THE
14TH DAY.
• WOUND IS REDUCED BY 80% OF ITS ORIGINAL SIZE WHICH HELPS IN
RAPID HEALING SINCE LESSER SURFACE AREA OF THE INJURED
TISSUE HAS TO BE REPLACED.
MECHANISM OF
WOUND
CONTRACTION
CONTRACTION OF COLLAGEN
DEHYDRATION
MYOFIBROBLASTS
16 / 69
DAS. CONCISE TEXTBOOK OF SURGERY, 3RD EDITION

17. WOUND HEALING
A WOUND IS A BREAK IN THE INTEGRITY OF THE
SKIN OR TISSUES OFTEN WHICH MAY BE
ASSOCIATED WITH DISRUPTION OF THE
STRUCTURE AND FUNCTION.
( SRB 4TH EDITION)
A WOUND IS A CUT OR BREAK IN THE
CONTINUITY OF ANY TISSUE, CAUSED BY INJURY
OR OPERATION.
( BAILLIERE’S 23RD EDITION )
17 /69
JOURNAL OF BURNS AND WOUNDS (http://www.ncbi.nlm.nih.gov/pmc/journals/211/)

18. 18 / 69
ROBBINS AND COTRAN, PATHOLOGIC BASIS OF DISEASE, 7TH ED.

19. Growth Factors and Cytokines Affecting Various Steps in
Wound Healing
Monocyte chemotaxis PDGF, FGF, TGF-ß
Fibroblast migration PDGF, EGF, FGF, TGF-ß, TNF,
IL-1
Fibroblast proliferation PDGF, EGF, FGF, TNF
Angiogenesis VEGF, Ang, FGF
Collagen synthesis TGF-ß, PDGF
Collagenase secretion PDGF, EGF, FGF, TNF, TGF-ß
inhibits
PDGF- platelet-derived growth factor
FGF- fibroblast growth factor
TGF- transforming growth factor
EGF- epidermal growth factor
IL- interleukin
TNF- tumor necrosis factor
VEGF- vascular endothelial growth factor
19 / 69
ROBBINS AND COTRAN, PATHOLOGIC BASIS OF DISEASE, 7TH ED.

20. 20 / 69

21. TYPES OF WOUND HEALING
WOUND HEALING CAN BE ACCOMPLISHED IN ONE OF THE
FOLLOWING WAYS:
• HEALING BY FIRST INTENTION
(PRIMARY UNION)
• HEALING BY SECOND INTENTION
(SECONDARY UNION)
• HEALING BY TERTIARY INTENTION
21 / 69
ESSENTIAL PATHOLOGY BY HARSHMOHAN, 4TH EDITION

22. Healing by First Intention (Primary Union)
• CLEAN INCISED WOUND OR SURGICAL UNINFECTED WOUND.
• MORE EPITHELIAL REGENERATION THAN FIBROSIS.
• WOUND HEALS RAPIDLY WITH COMPLETE CLOSURE WITHOUT MUCH
LOSS OF CELLS AND TISSUE.
22 / 69
ESSENTIAL PATHOLOGY BY HARSHMOHAN, 4TH EDITION

23. EVENTS IN PRIMARY UNION
• OCCURS WITHIN 24 HOURS.
• APPEARANCE OF POLYMORPHS, WHICH ARE REPLACED BY MACROPHAGES ON
3rd DAY.
INITIAL HAEMORRHAGE
ACUTE INFLAMMATORY
RESPONSE
EPITHELIAL CHANGES
ORGANISATION
SUTURE TRACKS
• BLOOD CLOTS IN THE SPACE BETWEEN APPROXIMATED INCISED WOUND SURFACES.
• IT SEALS THE WOUND AGAINST DEHYDRATION AND INFECTION.
•PROLIFERATION AND MIGRATION OF BASAL CELLS OF EPIDERMIS AS EPITHELIAL
SPURS.
•SCAB FORMATION SEPERATING UNDERLYING VIABLE DERMIS FROM OVERLYING
NECROTIC MATERIAL AND CLOT.
•BY 5TH DAY MULTILAYERED NEW EPIDERMIS IS FORMED
•BY 3RD DAY FIBROBLAST INVADE WOUND AREA .
•BY 5TH DAY NEW COLLAGEN FIBRILS IS FORMED.
•IN 4 WEEKS SCAR TISSUE WITH SCANTY CELLULAR AND VASCULAR ELEMENTS.
•FILLING SPACE WITH HAEMORRHAGE, INFLAMMATORY CELL
REACTION, FORMATION OF YOUNG COLLAGEN.
•STITCH ABSCESS, IMPLANTATION OR EPIDERMAL CYSTS.
23 / 69
BOYD’S TEXTBOOK OF PATHOLOGY 9TH EDITION

24. Suture Classification
24/69
Suture materials can be described in three ways, according to
their structure, source and fate within the body:-
•Structure – Monofilament/Braided/Barbed
• Source – Natural or Synthetic
• Fate – Absorbable or Non-absorbable

25. HEALING BY SECOND INTENTION (SECONDARY UNION)
• OPEN WOUND WITH LARGE TISSUE DEFECT, AT TIMES
INFECTED.
• EXTENSIVE LOSS OF CELLS AND TISSUES.
• WOUND IS NOT APPROXIMATED BY SURGICAL SUTURES BUT
IS LEFT OPEN.
25 / 69
ESSENTIAL PATHOLOGY BY HARSHMOHAN, 4TH EDITION

26. EVENTS IN SECONDARY UNION
INITIAL HAEMORRHAGE
INFLAMMATION
EPITHELIAL CHANGES
GRANULATION TISSUE
WOUND CONTRACTION
26 /69
BOYD’S TEXTBOOK OF PATHOLOGY 9TH EDITION

27. HEALING BY TERTIARY INTENTION
27/69
Tertiary wound healing, or healing by delayed primary closure, occurs when
there is a need to delay the wound-closing process. This occurs when the
process of secondary intention is intentionally interrupted and the wound is
mechanically closed. This usually occurs after granulation tissue has formed.

28. FEATURES PRIMARY SECONDARY
CLEANLINESS CLEAN NOT CLEAN
INFECTION NOT INFECTED INFECTED
MARGINS SURGICALLY CLEAN IRREGULAR
SUTURES USED NOT USED
HEALING SMALL GRANULATION
TISSUE
LARGE GRANULATION
TISSUE
OUT COME LINEAR SCAR IRREGULAR WOUND
COMPLICATION NOT FREQUENT FREQUENT
28/ 69
DAS. CONCISE TEXTBOOK OF SURGERY, 3RD EDITION

29. EXTRACELLULAR MATRIX : WOUND
STRENGTH
• THE ECM IS A STRUCTURAL SUPPORT NETWORK MADE
UP OF DIVERSE PROTEINS, SUGARS AND OTHER
COMPONENTS.
• IT INFLUENCES WIDE NUMBER OF CELLULAR
PROCESSES INCLUDING MIGRATION, WOUND HEALING
AND DIFFERENTIATION.
• ECM COMPRISES OF:
(1) FIBROUS STRUCTURAL PROTEIN – COLLAGENS AND
ELASTIN
(2) ADHESIVE GLYCOPROTEIN
(3) PROTEOGLYCANS AND HYALURONIC ACID
• THESE MACROMOLECULES ARE PRESENT IN
INTERCELLULAR JUNCTIONS AND CELL SURFACES
AND FORM TWO GENERAL ORGANIZATIONS:
 INTERSTITIAL MATRIX
 BASEMENT MEMBRANE 29 / 69
ESSENTIAL PATHOLOGY BY HARSHMOHAN, 4TH EDITION

30.  COLLAGEN:
- TYPE I: FOUND IN SKIN, BONE, AND
MATURE SCARS.
- TYPE II: CARTILAGE.
- TYPE III: ABUNDANT IN EMBRYONIC AND
PLIABLE TISSUES. FIRST COLLAGEN
DEPOSITED IN WOUND HEALING.
- TYPE IV: BASEMENT MEMBRANES AND
ASSOCIATED WITH LAMININ AND OTHER
MATRIX COMPONENTS.
30 / 69
ROBBINS AND COTRAN, PATHOLOGIC BASIS OF DISEASE, 7TH ED.

31.  COLLAGEN PROVIDES TENSILE
STRENGTH, WHEREAS ELASTIC FIBERS
PROVIDE RECOIL, AND THUS TEND TO BE
FOUND IN THE AORTA, SMALLER
ARTERIES, SKIN, LUNG, AND UTERUS.
ELASTIC FIBERS
31 / 69
ESSENTIAL PATHOLOGY BY HARSHMOHAN, 4TH EDITION

32. STRUCTURAL GLYCOPROTEIN
• FIBRONECTIN: (NECTERE, TO BIND)
• BINDS TO COLLAGENS, PROTEOGLYCANS,
FIBRINOGEN, FIBRIN, CELL SURFACES,
BACTERIA AND DNA.
• ONE OF THE FIRST STRUCTURAL MOLECULES
DEPOSITED DURING EMBRYONIC
DEVELOPMENT.
• FOUND IN TISSUE AND PLASMA.
• SYNTHESIZED BY HEPATOCYTES.
32 / 69
ESSENTIAL PATHOLOGY BY HARSHMOHAN, 4TH EDITION

33. • PROTEOGLYCANS:
• USED TO BE CALLED MUCOPOLYSACCHARIDES, BUT ARE NOW
REFFERED TO AS GLYCOSAMINOGLYCANS.
• HIGHLY HYDROPHILIC, AND FORM HYDRATED GELS, EVEN AT LOW
CONCENTRATION.
• SEEN IN EARLY WOUND HEALING
33 / 69
ESSENTIAL PATHOLOGY BY HARSHMOHAN, 4TH EDITION

34. FACTORS INFLUENCING HEALING
SYSTEMIC LOCAL
NUTRITION :- e.g. Protein and Vit.C
deficiency inhibit collagen Synthesis and
Retard Healing .
Infection- cause delay in wound healing.
Circulatory Status:- inadequate blood
supply caused by arteriosclerosis or
venous abnormalities also impair healing.
Mechanical factors:- such as early motion
of wounds cause delay in healing.
Hormones:- such as glucocorticoids will
inhibit collagen synthesis.
Foreign bodies:- ununecessary sutures or
fragments of steel, glass or even bone can
impede healing.
Systemic Conditions Retarding Healing:
AIDS/HIVinfection,Menopause,
Connective Tissue Disorder such as
EHLER DANLOS SYNDROME, CVS
Disease etc
Size, location and type of wound:- wound
in richly vascularized areas heals faster ,
small wounds produced intentionally
heals faster than larger ones caused by
trauma
34 / 69
ROBBINS AND COTRAN, PATHOLOGIC BASIS OF
DISEASE, 7TH ED.

35. SYSTEMIC MEDICATION AFFECTING
WOUND HEALING
- BISPHOSPHONATES: E.g. Etidronate,
Alendronate, Pamidronate
- GLUCOCORTICOIDS: E.g. Prednisone,
Beclomethasone
- NSAIDS: E.g. Diclofenac, Naproxen, Ibuprofen
- CYCLO OXYGENASE - 2 INHIBITORS: E.g.
Celecoxib, Rofecoxib
35 / 69
TEXTBOOK OF ESSENTIAL PATHOLOGY BY HARSHMOHAN, 4TH EDITION

36. COMPLICATIONS OF WOUND
HEALING
• INFECTION
• IMPLANTATION CYST (EPIDERMAL)
• PIGMENTATION
• DEFICIENT SCAR FORMATION
• INCISIONAL HERNIA
• HYPERTROPHIED SCARS AND
KELOID FORMATION
• EXCESSIVE CONTRACTION
• NEOPLASIA
36 / 69
COHEN’S , 11TH EDITION

37. FRACTURE HEALING
• PRIMARY UNION OF FRACTURE
• SECONDARY UNION OF FRACTURE
HEMATOMA
INGROWTH OF
GRANULATION TISSUE
REMODELLING
CALLUS COMPOSED OF
WOVEN BONE AND
CARTILAGE
OSSEOUS CALLUS
FORMATION
37 / 69
TEXTBOOK OF ESSENTIAL PATHOLOGY BY HARSHMOHAN, 4TH EDITION

38. HEALING OF ORAL WOUNDS
Oral wounds heal faster and with less scarring than extra oral wounds.
It is mainly due to:
• Saliva
• Bacteria
• Phenotype of cells
FACTOR MECHANISM
Saliva
Moisture,ionic strength,ions-Mg
and Ca
growth factors( EGF,VEGF,TGFB
etc}
Bacteria
Stimulation of macrophage influx,
Direct stimulative action on
keratinocyte and fibroblast.
Phenotype of cells
Fetal like fibroblasts with unique
response, specialized epithelium
and Connective Tissue
38 / 69

39. HEALING FOLLOWING SCALING &
ROOT PLANING
• 2 hours:
• Numerous
polymorphonuclear
leucocytes can be
seen b/w residual
epithelial cells &
crevicular surface.
• Dilation of blood
vessels, oedema &
necrosis in the
lateral wall of the
pocket
• 24 hrs: widespread
infiltration of
inflammatory cells
and migration of
keratinocytes have
been observed, in
all areas of the
remaining
epithelium
• 2 days: Entire
pocket is
epithelialized
39 / 69
NEWMAN, TAKEI,KLOKKEVOLD,CARRANZA. 10TH EDITION.

40. Healing following Curettage
A blood clot forms between the root surface & the lateral wall of the pocket,
soon after the curettage
Large number of polymorphonuclear leucocytes after the procedure
rapid proliferation of granulation tissue
 Epithelisation of the inner surface of the lateral wall is completed in 2-7 days
 The junctional epithelium is also formed in about 5 days
40 / 69
NEWMAN, TAKEI,KLOKKEVOLD,CARRANZA. 10TH EDITION.

41. 41
Healing after Surgical Gingivectomy
Initial response
formation of a protective surface clot
Clot is then replaced by granulation tissue
By 24 hours
There is an increase in new connective tissue cells, mainly angioblasts just
beneath the surface layer of inflammation and necrosis.
By the 3rd day
numerous young fibroblasts are located in the area which start granulation
tissue formation.
The highly vascular granulation tissue grows coronally, creating a new free
gingival margin and sulcus .Capillaries derived from the blood vessels of the
periodontal ligament migrate in to the granulation tissue
41/ 69

42. 42
within 2 weeks they connect with gingiva vessels
After 5-14 days surface epitheliazation is complete
During first 4 weeks keratinization is less than it was before surgery
1 month Complete epithelial repair
7 weeks Complete repair of the C.T.
Flow of GCF is initially increased after gingivectomy and diminishes as
healing progresses.
42/ 69
NEWMAN, TAKEI,KLOKKEVOLD,CARRANZA. 10TH EDITION.

43. HEALING FOLLOWING FLAP SURGERY
Clot formation
1-3 days, migration of epithelial cells
by 1 week, epithelial attachment by means of hemidesmosomes
granulation tissue replaces clot
by 2nd week, collagen fibres appear & arranged parallel to root surface
by end of 1 month, well formed epithelial attachment
43 / 69
LINDHE’S CLINICAL PERIODONTOLOGY 7TH ED.

44. SOCKET HEALING WITH GRAFT MATERIAL
PEDRO DE SOUSA GOMES ET AL CONCLUDED THAT:
Graft materials act as solid scaffolds which assist on coagulum stabilization during
the early phases of healing, by impeding the interference of destabilizing factors on
the clot maturation process.
Some graft materials may have a direct modulatory effect on the cellular behaviour,
leading to an increased production of extracellular matrix and its subsequent
maturation.
Socket grafting seems to be effective on allowing for the formation of mature bone,
further promoting ridge preservation by limiting the physiologic reduction, as
compared to ungrafted healing.
44 / 69
Journal of oral and maxillofacial research 2019 July-sep

45. HEALING FOLLOWING GINGIVAL DEPIGMENTATION
The initial response
formation of protective
surface clot
Within 2 weeks,
capillaries connect with
gingival vessels
Capillaries derived from
blood vessels of PDL,
migrate into the GT
The underlying tissues
become acutely
inflamed,with some
necrosis.
Clot is then replaced by
granulation tissue.
Complete epithelial
repair takes about
1 month.
After 5-14 days surface
epithelization is
generally complete.
Vascularity returns to
normal in about 2-3
weeks.
Vascularity increases
thn begins to decrease
gradually as healing
takes place.
45 / 69
NEWMAN, TAKEI,KLOKKEVOLD,CARRANZA. 10TH EDITION.

46. STEM CELLS FOR REGENERATION
• Dental Stem cells can be isolated from dental tissues like
periodontal ligament, pulp of human exfoliated teeth or dental
follicle.
• Dental stem cells could be feasible tools for dental tissue
engineering.
• Stem cells are defined as ‘clonogenic cells capable of both self
renewal and multi-lineage’.
 IN GENERAL ,THREE CATEGORIES CAN BE
IDENTIFIED:-
• Embryonic stem cells(pluripotent)
• Adult stem cells(multipotent)
• Reprogrammed stem cells(either pluripotent or multipotent)
46 / 69

47. STEM CELLS OF DENTAL TISSUE ORIGIN
• SHED: STEM CELLS FROM EXFOLIATED
DECIDUOUS TEETH
• DFSC: DENTAL FOLLICLE STEM CELLS
• DPSC: DENTAL PULP STEM CELLS
• PDSC: PERIODONTAL LIGAMENT STEM CELLS
• APICAL PAPILLA STEM CELLS
• EMBRYONIC STEM CELLS
47 / 69

48. STEM CELLS FOR PERIODONTAL REGENERATION
• Procedures to achieve periodontal regeneration have included root surface
conditioning, bone graft placement and growth factor application.
• One approach to periodontal regeneration involves incorporation of
progenitor cells in periodontal defect.
• Periodontal ligament stem cells have been shown to give rise to adherent
clonogenic clusters resembling fibroblasts that may develop into adipocytes,
osteoblast like cells and cementoblast like cells in vitro.
48 / 69

49. 49 / 69
STEM CELLS IN REGENERATIVE ENDODONTICS
• UNSPECIALIZED CELLS.
• CAN DIVIDE THROUGH MITOSIS
• DIFFERENTIATE INTO SPECIALIZED CELL TYPES
• SELF RENEW TO PRODUCE MORE STEM CELLS

50. ENDODONTIC IMPLICATIONS
ENDODONTIC IMPLICATIONS
ENDODONTIC IMPLICATIONS
• THE REACTION OF THE PERIRADICULAR TISSUES TO NOXIOUS
PRODUCTS OF TISSUE NECROSIS, BACTERIAL PRODUCTS AND
ANTIGENIC AGENTS FROM THE ROOT CANAL HAS BEEN DESCRIBED BY
FISH.
• FOUR WELL-DEFINED ZONES OF REACTION GIVEN BY FISH-
ZONE OF INFECTION
ZONE OF
CONTAMINATION
ZONE OF IRRITATION
ZONE OF
STIMULATION
50 / 69
COHEN’S , 11TH EDITION

51. WOUND HEALING AFTER
ENDODONTIC SURGERY
• THE INTIAL REPAIR THAT FOLLOWS A PERIRADICULAR
SURGICAL PROCEDURE OCCURS ACROSS THE MARGINS OF THE
LINE OF INCISION.
• THIS HEALING BY 1ST INTENTION USUALLY OCCUR WITHIN 5
DAYS, PROVIDED THE SUTURE REMAIN INTACT.
• IF THE SUTURES TEAR OR FAIL, THEN HEALING OCCUR BY
FORMATION OF GRANULATION TISSUE ( 2ND INTENTION) WHICH
LASTS FOR 4-6 WEEKS.
• REPAIR OF PERIRADICULAR TISSUES IS USUALLY COMPLETED
WITHIN A YEAR, AND A PROGRESSIVE REPAIR SHOULD BE
NOTICEABLE ON A RADIOGRAPH 6 MONTHS AFTER THE
OPERATION.
51 / 69
COHEN’S , 11TH EDITION

52. DENTAL IMPLANTS AND HEALING
Soroush Irandoust & Sinan Müftü Concluded That:
Long-term bone healing/adaptation after a dental implant treatment starts with diffusion of
mesenchymal stem cells to the wounded region and their subsequent differentiation.
The healing phase is followed by the bone-remodeling phase.
The first and most important healing phase, osteoconduction, relies on the recruitment and
migration of osteogenic cells to the implant surface, through the residue of the peri-implant
blood clot.
The most important aspects of osteoconduction are the knock-on effects generated at the
implant surface, by the initiation of platelet activation, which result in directed osteogenic
cell migration.
There is de novo bone formation, which results in a mineralized interfacial matrix
equivalent to that seen in the cement line in natural bone tissue.
52 / 69
EUROPEAN CELLS AND MATERIALS , VOL. 38, 2019

53. PLATELET RICH FIBRIN (PRF) IN
TISSUE HEALING AND
REGENERATION
JOHAN HARTSHORNE AND HOWARD GLUCKMAN
CONCLUDED THAT:
PRF IS INCREASINGLY BEING INVESTIGATED AND USED BY CLINICIANS
WORLDWIDE AS AN ADJUNCTIVE AUTOLOGOUS BIOMATERIAL TO PROMOTE
BONE AND SOFT TISSUE HEALING AND REGENERATION. IT IS DERIVED FROM
PATIENT’S OWN BLOOD, EASY TO MAKE AT CHAIRSIDE, EASY TO USE WITH
DAILY CLINICAL ROUTINE, WIDELY APPLICABLE WITH NO RISK OF REJECTION,
WHILST BEING FINANCIALLY REALISTIC FOR THE PATIENT.
53 / 69

54. FURTHER:
THE GOLD STANDARD FOR IN-VIVO TISSUE HEALING AND REGENERATION REQUIRES THE
MUTUAL INTERACTION BETWEEN A SCAFFOLD (FIBRIN MATRIX), PLATELETS, GROWTH
FACTORS, LEUKOCYTES, AND STEM CELLS. THESE KEY ELEMENTS ARE ALL ACTIVE
COMPONENTS OF PRF AND WHEN COMBINED AND PREPARED PROPERLY ARE INVOLVED IN
KEY PROCESSES OF TISSUE HEALING AND REGENERATION , WHILST AT THE SAME TIME
REDUCING ADVERSE EVENTS.
IT IS USED IN IMPLANTOLOGY, PERIODONTOLOGY, ORAL AND MAXILLOFACIAL SURGERY,
AND LATELY IN REGENERATIVE ENDODONTICS TO PROMOTE WOUND HEALING AMD
REGENERATION.
54 / 69
ENDODONTIC REGENERATION : MATTHIAS WIDBILLER ET AL

55. HEALING OF SINUS TRACT
• SINUS IS A TRACT LEADING FROM AN ENCLOSED AREA
OF INFLAMMATION TO AN EPITHELIAL SURFACE, AND IS
ONE OF THE SEQUELAE OF INFLAMMATORY DISEASE.
• A SINUS TRACT IS A DRAINAGE DUCT FOR THE
SUPPURATION PRODUCED BY ABSCESSES.
• SUPPURATION FROM THE PERIAPICAL INFLAMMATORY
PROCESS MAY BE RESORBED BY THE HOST ORGANISM,
OR ELSE IT WILL FLOW THROUGH THE LESS RESISTANT
TISSUE AREA.
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DAS. CONCISE TEXTBOOK OF SURGERY, 3RD EDITION

56. TREATMENT OF SINUS TRACT
• TREATMENT IS DIRECTED TOWARDS ELIMINATION OF THE SOURCE OF
INFECTION.
• OFFENDING TOOTH IS REMOVED IF IT IS TOO BADLY DECAYED, OR IF THERE
IS EXTENSIVE LOSS OF THE SURROUNDING ALVEOLAR BONE.
• IN MOST CASES, THE SINUS TRACT HEALS SPONTANEOUSLY IF THE INFECTED
PULP IS REMOVED, AND THE ROOT CANAL DEBRIDED AND FILLED.
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DAS. CONCISE TEXTBOOK OF SURGERY, 3RD EDITION

57. HEALING AFTER EXTRACTION OF
TOOTH
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DAS. CONCISE TEXTBOOK OF SURGERY, 3RD EDITION

58. HEALING OF RESIDUALALVEOLAR RIDGES
- RESIDUAL RIDGE IS THE TERM USED TO DESCRIBE THE
SHAPE OF THE CLINICAL ALVEOLAR RIDGE AFTER
HEALING OF THE BONE AND SOFT TISSUES AFTER
TOOTH EXTRACTION.
- AFTER TOOTH EXTRACTION, A CASCADE OF
INFLAMMATORY REACTIONS IS IMMEDIATELY
ACTIVATED, AND EXTRACTION SOCKET IS
TEMPORARILY CLOSED BY THE BLOOD CLOT.
- THERE IS PROLIFERATION AND MIGRATION OF
EPITHELIAL TISSUE WITHIN FIRST WEEK AND
DISRUPTED TISSUE INTEGRITY IS QUICKLY RESTORED.
- THE MOST STRIKING FEATURE OF THE EXTRACTION
WOUND HEALING IS THAT EVEN AFTER HEALING OF
THE WOUNDS, THE RESIDUAL ALVEOLAR RIDGE BONE
UNDERGOES A LIFE LONG CATABOLIC REMODELLING.
58 / 69
DEEPAK NALLASWAMY VEERAIYAN, 2ND EDITION

59. HEALING OF REIMPLANTED TOOTH
Clot
Fibroblast Proliferation
Reconnection
Reattachment of epithelium by 7th day
Complete regeneration of pdl within
2-4 weeks
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NEWMAN, TAKEI,KLOKKEVOLD,CARRANZA. 10TH EDITION.

60. REMODELLING OF BONE IN ORTHODONTIC TOOTH
MOVEMENT
- BONE REMODELLING IS A COUPLED PROCESS IN
WHICH THERE IS LOCALIZED REMOVAL OF OLD
BONE (RESORPTION) AND REPLACEMENT WITH
NEWELY FORMED BONE.
-THE MAJOR REASON FOR REMODELLING IS TO
ENABLE THE BONE TO RESPOND, AND ADAPT TO
MECHANICAL STRESSES AS SEEN DURING
MECHANICAL LOADING DURING ORTHODONTIC
TOOTH MOVEMENT, AND IN ROOT RESORPTION.
- IN PRESSURE SIDE, OSTEOCLASTS RELEASE H
IONS TO DISSOLVE THE INORGANIC MATRIX AND
ENZYMES SUCH AS MMPs AND CATHEPSINS
RESORB ORGANIC MATRIX IN BONE.
- IN THE TENSION SIDE, OSTEOBLASTS FORMS NEW
BONE BY PRODUCING NEW ECM AND THEN
MINERALIZING IT.
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INTERNATIONAL JOURNAL OF ORAL SCIENCE, (2021)13:20 BY YUAN LI ET AL

61. HEALING IN PATIENTS ON CHEMOTHERAPY/ RADIATION THERAPY
- THERE IS IMPAIRED HEALING RESPONSE.
-PULP MAY BECOME NECROTIC DURING RADIATION THERAPY.
-SYMPTOMATIC NONVITAL TEETH SHOULD BE ENDODONTICALLY
TREATED 1 WEEK BEFORE INITIATING RADIATION OR
CHEMOTHERAPY WHEREAS ASYMPTOMATIC NONVITAL TEETH MAY
BE DELAYED.
-DUE TO THE RISK OF OSTEORADIONECROSIS, ALL INVASIVE
SURGICAL PROCEDURES SHOULD BE AVOIDED FOR ATLEAST 6
MONTHS AFTER RADIATION THERAPY.
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INGLE’S ENDODONTICS, 6TH EDITION

62. RECENT TRENDS IN MANAGEMENT OF WOUNDS
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• Biopolymers, polymers that produced by living microorganisms are commonly
used as wound management.
• The used materials in wound dressings involve films, sponges, fibers or
hydrogels from natural and synthetic polymers and their combinations

63. 63 / 69
Wound dressings from naturally-occurred polymers:
Naturally-occurring polymers are generally chosen for wound management over
synthetic polymers because they are economical, non-toxic to human body and
environmental-friendly. Polysaccharides are natural polymers which are frequently
applied as wound dressing materials. Cellulose, chitosan, pullulan, starch and β-
glucan, as well as collagen, hyaluronic acid and alginate are among the most used
polymers as wound dressings.
Chitosan (CS) is a well studied natural polymer, frequently used in biomedical
applications because of its antimicrobial activity and healing stimulation. It also
promotes drainage, prevents the buildup of exudates, and serves as auto-grafting bed
in wound therapy.

64. SUMMARY
The process by which healing occurs in a tissue is dependent on several factors:
-TYPE OF CELL, EXTENT OF INJURY ETC.
Depending on the type of wounds, healing process follows two pathways:
-HEALING BY PRIMARY INTENTION
-HEALING BY SECONDARY INTENTION
There are systemic and local factors which may delay wound healing (e.g. vitamin
deficiency, systemic conditions such as diabetes, cardiovascular diseases, drugs such as
nsaids, bisphosphonates etc.)
Complications of wound healing includes keloid formation, implantation cyst formation,
infection etc.
Factors which promotes healing includes good blood supply, nutrition, age , site of
wound etc.
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65. CONCLUSION
UNDERSTANDING OF WOUND HEALING IS AS IMPORTANT AS
KNOWING THE PATHOGENESIS OF DISEASE, BECAUSE
SATISFACTORY WOUND HEALING IS THE ULTIMATE GOAL OF
TREATMENT.
IF WE ARE ABLE TO UNDERSTAND THE MECHANISM OF
PERIAPICAL WOUND HEALING, WE CAN DESIGN TREATMENT
APPROACHES THAT CAN MAXIMIZE FAVOURABLE CONDITIONS
FOR WOUND HEALING TO OCCUR.
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66. • TEXTBOOK OF ESSENTIAL PATHOLOGY BY
HARSHMOHAN, 4TH EDITION
• ROBBINS AND COTRAN, PATHOLOGIC BASIS OF
DISEASE, 7TH EDITION
• BOYD’S TEXTBOOK OF PATHOLOGY 9TH EDITION
• DAS. CONCISE TEXTBOOK OF SURGERY, 3RD
EDITION
• LINDHE’S CLINICAL PERIODONTOLOGY 7TH
EDITION
• JOURNAL OF BURNS AND WOUNDS
(http://www.ncbi.nlm.nih.gov/pmc/journals/211/)
REFERENCES
66 / 69

67. 67 / 69
• DEEPAK NALLASWAMY VEERAIYAN, 2ND EDITION
• ASIAN JOURNAL OF PHARMACEUTICAL SCIENCES 2020
• PHILLIPS’ SCIENCE OF DENTAL MATERIALS, 12TH
EDITION
• NEWMAN, TAKEI,KLOKKEVOLD,CARRANZA. 10TH
EDITION.
• BAU JOURNAL- HEALTH AND WELLBEING , ARTICLE 7,
VOLUME 2, ISSUE 1
• SRB’ S MANUAL OF SURGERY, 4TH EDITION
• Basic Considerations of wound Healing.Periodontology 2000 vol
19

68. 68

69. 69