Wound healing

Wound healing, methods to
control hemorrhage, suturing
and bone grafts
www.indiandentalacademy.com

Contents :
Wound healing
Regeneration & repair
Healing by primary intention & secondary
intention
Healing of extraction socket & its complications
Methods of control of hemorrhage
Mechanical
Thermal
Chemical
Suturing
Needles
Suture materials
Bone graft materials
Classification & typeswww.indiandentalacademy.com

Introduction

HEALING OF TISSUE
Is the body response to injury to
restore normal structure and function
Involves 2 processes
Regeneration- parenchymal
Repair – CT

REGENERATION:

REPAIR:
Healing by connective tissue
Granulation tissue is formed in 3-5
days
2 steps in repair
1. granulation tissue formation
2. contraction of wounds

Granulation tissue formation
1. phase of inflammation
2. phase of clearance
3. phase of ingrowth
angiogenesis
fibrogenesis
Contraction of wounds

Scar formation
Fibroblast migration & proliferation
ECM deposition & Scar formation
Tissue remodeling (metalloprotenases)

Wound Healing:
Inflammation
Epithelialization
Granulation
Contraction
Remodeling

Healing by Primary
Intention:
Healing of clean, uninfected,
surgical incisions
Focal disruptions of basement
memb. Continuity
Within 24 hrs.
Netrophils…
Inc. mitotic activity of basal cells
Cells meet in midline below scab

Day 3 :
Neutrophils replaced by macrophages
Invasion of granulation tissue
Vertically oriented collagen fibers
Thick epithelial covering
Day 5 :
Neovascularisation – peak
Abundant collagen fibers
Differentiation - keratinisation

During 2nd
week:
Continued collagen accumulation &
fibroblast proliferation
Vascularity, edema, leukocyte
infiltration decrease
Collagen inc.
By end of 1st month:
Scar devoid of inflammatory cells
Dermal appendages lost permanently
Tensile strength inc. …www.indiandentalacademy.com

Healing by Secondary
Intention:
More extensive wounds – infarcts,
inflamm. Ulcers, abcess or large
wounds
Healing from below upwards &
margain inwards
Slow & leads to scar…

Intial hemorrhage:
Wound filled with blood & fibrin clot
Inflammatory phase:
Acute inflamm cells, then macrophages
Epithelial changes:
Proliferation from both margins
Surface not covered till granulation
tissue starts filling wound space
Scab cast off

Granulation tissue:
Main bulk
Fibroblasts & neovascularisation
Deep red, granular & fragile but – pale
Wound contraction:
Not seen in primary healing
Due to myofibroblasts
1/3 – ¼ the original size

Healing by secondary
intention

Wound Strength
Sutured wounds – 70% of
unwounded skin
1 week- 10%
4 week- inc
3 month- 70-80%
No further increase

Complications…
Infection
Pigmentation
Implantation
Deficient scar
Hypertropied scar & Keloid
Excessive contraction
Neoplasia
Incisional hernia

Conditions for Healing
• Well being
• Nutrition
• Vascular supply/drainage
• Clean wound
• Minimal trauma
• Moist environment
• Thermal regulation

Healing of
extraction socket

Healing Of Extraction
Socket
Immediate Reaction :
Blood fills the socket & coagulates
Torn blood vessels – sealed off
Vasodilation & engorgement
Leukoytes around the clot
Clot contraction
Unsupported gingival tissue
First Week Wound :
Fibroblast proliferation
Clot acts as scaffold
Mild mitotic activity
Clot organization, no osteoid formation

Second Week Wound :
Clot organization progresses
Remnants of PDL – degeneration
Epithelial Proliferation
Socket margins – osteoclastic activity
Third Week Wound :
Clot totally organized
Osteoid bone formation
Rounded crest
Complete epithelisation of surface
Fourth Week Wound :
Continuous remodeling & deposition
Crest below adjacent tooth
Radiographic evidence – 6-8 weeks

Complication of socket
healing
Dry Socket/Alveolitis Sicca
Dolorosa/Alveolitis Osteitis/Acute
Alveolar Osteomyelitis/Alveolagia
Most common
Focal osteomyelitis- disintegration of
clot
95% in lower premolars & molars
Within 1st
few days…
Extremely painful
Palliative medicine & allow healing
Tetracycline hydrochloride…
Pack socket with obtundant

Fibrous healing
Uncommon …
Loss of labial & lingual plates
Asymptomatic
Dense fibrous mass on exploration
Excision causes bony repair

Methods to controlMethods to control
HemorrhageHemorrhage
Control dependent on :Control dependent on :
Vessel contraction
Retraction
Clot formation

Techniques :Techniques :
Mechanical
Thermal
Chemical

Mechanical methodsMechanical methods
Pressure :Pressure :
Counter hydrostatic
pressure
5 min…
Most common
Use of Hemostats:Use of Hemostats:
Mosquito or straight
Larger vessels - ligation

Sutures & ligationSutures & ligation
Large artery – 3-0 non-absorbable
Small artery – catgut & polygalactin
Large pulsatile artery – double
transfixation
Embolisation of vesselsEmbolisation of vessels
Angiography – bleeding point
Steel coil, polyvinyl alcohol foam, gel
foam, silicon spheres & methyl
methacrylate
Contrast media – catheter…
Lesion mapped, & embolisation done

Thermal AgentsThermal Agents
CauteryCautery
Heat transmitted from instrument
Denaturation of proteins
ElectrosurgeryElectrosurgery
Induction
Large vessels

CryosurgeryCryosurgery
-20c - -180c
Cryogenic necrosis –dehydration & denaturation
of lipid mol.
Superficial hemangiomas
Argon beam coagulatorArgon beam coagulator
Monoplanar current – flow of argon
Vessels < 3mm
Tip kept 1-2 mm away
No gas embolism
LasersLasers

Chemical MethodsChemical Methods
Local agents:Local agents:
Astringent & styptics :
Monsel sol.- ferric subsulphate –
capillary & post-extraction bleeding
Tannic acid – ppt. proteins
Tea bag
Mann hemostatic- tannic acid + alum &
chlorambutol
Silver nitrate & FeCl3
Bone wax
Mechanical occlusion
Foreign body granuloma & infection

Thrombin
Fibrinogen to fibrin
Pack, gelatin sponge or surgicel
Gelfoam
No hemostatic action…
Pressure & scaffold for fibrin retention
Oxycel
Oxidized cellulose – affinity for Hb –
artificial clot
To be applied dry

Surgicel
Glucose polymer based knitted fabric
Hb – oxycellulose binding…
Does not inhibit epithelisation
Fibrin glue
Thrombin + fibrinogen + factor 13 + apoprotinin
Unstable clot
Stabilizes clot
Prevents degradation
Adrenaline
Vasoconstriction
Hypertensive & Cardiac pt.

SuturingSuturing
material
Stainless steel
Carbon steel
shape
straight
curved
tapered
cutting
tapered
cutting
Needles

Straight needle :Straight needle :
Skin closure – adequate access
Circumzygomatic & circummandibular wires
Curved needleCurved needle
Skin & mucus memb.
¼, 3/8, ½ & 5/8 circle…
Cutting edge :
Conventional
Reverse cutting
Suture attachments :Suture attachments :
Swaged
Eyed needle

Ideal property of suture material.:Ideal property of suture material.:
Strength
Good handling & knot tying
Sterlizable
Evoke little tissue reaction
No 3 largest & 7-0 smallestNo 3 largest & 7-0 smallest
5-0 , 6-0 – skin closure5-0 , 6-0 – skin closure
3-0 , 4-0 - intraoral3-0 , 4-0 - intraoral
Suture materialsSuture materials

CC
LL
AA
SS
SS
II
FF
II
CC
AA
TT
II
OO
NN

Suture SizeSuture Size
Sized according to diameter with “0” as referenceSized according to diameter with “0” as reference
sizesize
Numbers alone indicate progressively larger suturesNumbers alone indicate progressively larger sutures
(“1”, “2”, etc)(“1”, “2”, etc)
Numbers followed by a “0” indicate progressivelyNumbers followed by a “0” indicate progressively
smaller sutures (“2-0”, “4-0”, etc)smaller sutures (“2-0”, “4-0”, etc)
SmallerSmaller --------------------------------------------------------------------------
LargerLarger
.....”3-0”...”2-0”...”1-0”...”0”...”1”...”2”...”3”..........”3-0”...”2-0”...”1-0”...”0”...”1”...”2”...”3”.....

Absorbable SuturesAbsorbable Sutures
Gut :Gut :
Oldest…
Sheep intestinal mucosa & bovine intestinal
Serosa
Monofilamentous but microscopically…
Smallest tensile strength – Herrmann(1971)
Enzymatic degradation…
3-5 days…
Disadvantage:
Stiff
Insecure knot tying when wet

Chromic gut :Chromic gut :
Tanned with Cr
Cr salts :
Cross linking agent
Increase tensile strength
Resistance to absorption
Degraded in 7 days
CollagenCollagen
Deep flexor tendon of cattle
Not used

Polyglyolic acid & polygalactin 910Polyglyolic acid & polygalactin 910
Resorbed by hydrolysis
Synthetic polymers – little tissue
reaction
Polygalactin 910 – copolymer of
glycolide & lactide
Strongest absorbable suture mat.
Last in excess of 14 days (Wallace,
Maxwell & Calavaris) – so cut at 5 days
Difficult in tying… wet with saline

Non-Absorbable SuturesNon-Absorbable Sutures
SilkSilk
Most common
Slow proteolysis
Moderate response
Low tensile strength
3 ties per knot

NylonNylon
Braided or monofilamentous
Minimal tissue reaction – antibacterial
‘Memory’ …
Knots slip & untie
‘one knot for every day ‘
Good tensile strength
Not used intraorally :
Large knot needed
Tendency to tear non-keratinized mucosa
Stiffness
Cotton & linenCotton & linen
Noncontinous natural fibres of cotton
Linen stronger than cotton

Dacron polyester, polypropylene,Dacron polyester, polypropylene,
polyethylene, silicone coated dacronpolyethylene, silicone coated dacron
polyester:polyester:
Greatest tensile strength & knot holding
ability
Minimal tissue reaction
High coefficient of friction…
Metal :Metal :
Stainless steel & tantalum
Braided or monofilamentous
Strongest & most secure knot
Stiff materials…
Suspension of splints & arch bars

Steri-stripsSteri-strips
Sterile adhesiveSterile adhesive
tapestapes
Available inAvailable in
different widthsdifferent widths
Frequently used withFrequently used with
subcuticular suturessubcuticular sutures
Used followingUsed following
staple or suturestaple or suture
removalremoval
Can be used forCan be used for
delayed closuredelayed closure

StaplesStaples
Rapid closure ofRapid closure of
woundwound
Easy to applyEasy to apply
Evert tissue whenEvert tissue when
placed properlyplaced properly

Principles of Suturing:Principles of Suturing:
Grasp needle at ¾ from pointGrasp needle at ¾ from point
Needle to enter perpendicularNeedle to enter perpendicular
To follow curvatureTo follow curvature
Equal distance & depth fromEqual distance & depth from
incision lineincision line
From free to fixed sideFrom free to fixed side
From deeper to superficial sideFrom deeper to superficial side

Distance in tissues greater thanDistance in tissues greater than
distance from tissue edgedistance from tissue edge
No closure under tension thusNo closure under tension thus
approximated not blanchedapproximated not blanched
Knot not over incision lineKnot not over incision line
3-4 mm apart3-4 mm apart
Prevent dog-ear formationPrevent dog-ear formation

Simple SuturesSimple Sutures
Simple interruptedSimple interrupted
stitchstitch
Single stitches,
individually knotted
(keep all knots on one
side of wound)
Used for
uncomplicated
laceration repair and
wound closure
Suturing techniques:

Mattress SuturesMattress Sutures
Horizontal mattressHorizontal mattress
stitchstitch
Provides added strength
in fascial closure; also
used in calloused skin
(e.g. palms and soles)
Two-step stitch:
Simple stitch made
Needle reversed and 2nd
simple stitch made
adjacent to first (same
size bite as first stitch)

Mattress SuturesMattress Sutures
Vertical mattressVertical mattress
stitchstitch
Affords precise
approximation of skin
edges with eversion
Two-step stitch:
Simple stitch made –
“far, far” relative to
wound edge (large bite)
Needle reversed and
2nd simple stitch made
inside first – “near,
near” (small bite)

Subcuticular SuturesSubcuticular Sutures
Usually a runningUsually a running
stitch, but can bestitch, but can be
interruptedinterrupted
IntradermalIntradermal
horizontal biteshorizontal bites
Allow suture toAllow suture to
remain for a longerremain for a longer
period of timeperiod of time
without developmentwithout development
of crosshatchof crosshatch
scarringscarring

Bone Graft Materials :
Definition :
‘A graft is a viable tissue that
after removal from a donor site is
implanted within the host tissue
which is then restored, repaired
or regenerated.’
GRAFT
SOFT TISSUE GRAFT BONE GRAFT COMPOSITE GRAFT

Bone graft materials support bone
growth by :
Osteogenesis :
– Direct formation through osteoblasts
Osteoinduction :
– Transformation of mesenchymal cells to
osteoblasts
Osteoconduction :
– Stimulation of attachment, migration &
distribution of vascular & osteogenic cells

Osteoconduction depends on :
Porosity
Pore-size
3-D architecture
Osteoinduction involves :
Pluripotent & BMP

Kazanjian’s rules : (1952)
Adequate blood supply of recipient site
Bone to bone contact – ‘ creeping
substitution’
Rigid fixation
Bone graft to be placed in healthy tissue

BONE GRAFTS are used —
Management of non union & delayed
union
Filling of osseous defects
Replacement of bone & joint loss
Augmentation of skeletal deficiency
Fusion of growth plate cartilages

Ideal requirements of bone grafts:
Biologically acceptable
Predictability
Clinical feasibility
Minimal operative hazards
Minimal post-operative sequelae
Patient acceptance

Classification of bone grafts
BASED ON ---
1.ORIGIN
- autograft
- allograft
- xenograft
- bone substitute material

2. STRUCTURE
- cortical graft
- cancellous graft
- corticocancellous
3. BLOOD SUPPLY
- non-vascularized graft
- vascularized graft

Autografts :
defined as tissue transplanted from one
site to another within the same individual.
considered as gold standard
ADVANTAGES:
No immunologic sequelae
Rapid technique
Disadvantages :
insufficient amount
cortical bone is obtained

Osseous coagulum : (Robinson)
Bone dust + blood mixture
Uses particles from cortical bone
Bone blend:
Bone dust + Saline
Bone used is cortical & cancellous

Areas for obtaining bone grafts
Head & neck
Cranium
Mandible
Thorax
Ribs
Scapula
Forearm
Lower limb
Hip (Iliac crest)
Tibia
Fibula
2nd
metatarsal www.indiandentalacademy.com

Allografts : Defined as a tissue graft between
individuals of same species (i.e.,humans) but
of non-identical genetic composition
Cadavers are common source
Allograft
Fresh frozen Freeze dried bone
Decalcified freeze
dried bone

FRESH FROZEN
- Harvested under sterile condition
- kept frozen at -80—does not undergo enzymatic
destruction
FREEZE DRIED (lyphophylized) bone (FDB)
- Mainly used as a composite
- bending strength is lowered to 55-90%
- retain its antigenicity
DECALCIFIED FREEZE DRIED BONE (DFDB)
- retains its osteoinductiveness
Treated with radiations, freezing & chemicals

Advantages :
Sufficient quantity can be obtained
Bone banks
Can be stored at room temperature
Disadvantages :
Difficulty in finding donor
Risk of disease transmission
Immunological reaction
Sophisticated lab procedureswww.indiandentalacademy.com

XENOGRAFT-- defined as a tissue
graft between two different species
Examples :
- Kiel bone
- Frozen calf bone
- Freeze dried calf bone
- Decalcified Ox bone
- Ospurum
- Anorganic bone
- Boplant

Alloplasts / non- bone graft materials:
Examples :
- POP
- cartilage
- sclera of eye
- collagen material
Ceramic or synthetic bone grafts:
Resorbable
– Tricalium phosphate, resorbable hydroxyapatite
Non-resorbable
– Dense HA. Porous HA, Bioglasswww.indiandentalacademy.com

Advantage :
No processing
Biocompatible
Ease of manipulation
Disadvantage :
Cost

…..Conclusion

1. Robbin’s & Cotron Pathological basis of
diseases -7th
edn.
2. Essential pathology for dental students –Harsh
mohan,3rd
edn.
3. Text book of oral pathology – Shafer 4th
edn.
4. Contemporary oral & maxillofacial surgery –
Peterson.
5. Textbook of oral and maxillofacial surgery –
Neelima Malik
6. Textbook of oral and maxillofacial surgery –
Laskin vol 1
7. Short practice of surgery – Bailey and Love 23rd
edi.
REFERENCESREFERENCES
and maxillofacial surgery –and maxillofacial surgery –

Thank you

Next journal club on Saturday (13-5-06):

Wound healing

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (10)

Similar to Wound healing

Similar to Wound healing (20)

More from Indian dental academy

More from Indian dental academy (20)

Recently uploaded

Recently uploaded (20)

Wound healing