3. REGENERATIVE ENDODONTICS
The American Association of Endodontics defines
regenerative endodontics as “ biologically based
procedures designed to physiologically replace
damaged tooth structures, including dentin and root
structures as well as cells of the pulp-dentin complex.”
4. RECOMMENDATIONS FOR REGENERATIVE
ENDODONTICS
Type of tooth injury
Fracture type
Presence of necrosis or infection
Periodontal status
Presence of periapical lesions
Stage of tooth development
Vitality status
Patient age and health status
5. STEPS TO ACCOMPLISH REGENERATIVE ENDODONTIC
TREATMENT
Immature permanent tooth vitality
Non vital teeth with necrotic pulp
Non surgical root
canal
MTA
apexification
Root canal
revascularization
Endodontic
regeneration
Vital teeth with
healthy pulp
Root canal
apexogenesis
6. COMPONENTS OF REGENERATIVE ENDODONTICS
The three key elements for tissue regeneration are :
1) Stem cells (hard tissue formation)
2) Growth factors (cellular
stimulation,proliferation,differentiation)
3) Scaffold (support cell growth and differentiation)
7.
8. RECOMMENDATIONS FOR REVASCULARIZATION
The traumatized tooth must be non vital and not suitable
for apexogenesis,apexification,partial pulpotomy.
The tooth must be permanent and immature with a wide
open apex and exposed pulp
Anesthetic without a vasoconstrictor should be used
Endodontic sealer is not biocompatible for regeneration
and cannot be used.
A thin layer of MTA or calcium hydroxide should be placed
above the blood clot since the restorative materials
(amalgam,GIC,composite) are not biocompatible to the
exposed pulp tissues
The tooth should be restored with a resin modified glass
ionomer to prevent microleakage
9. PHASES OF PULP REVASCULARIZATION PROCEDURES
First phase of treatment : consists of debridement and
antibacterial medication
Interim phase : consist of interim medication
replacement
Final phase : completion of regenerative treatment in
an immature permanent tooth with a necrotic pulp. It
does not include final restoration.
10. SCAFFOLDS:
Scaffold provides the framework for cell growth and
differentiation at a local site.
A scaffold should be porous,biocompatible with the
host tissues , the correct shape and form to allow for
replacement of the lost tissues and biodegradable.
11.
12. TYPES OF SCAFFOLDS :
It includes two types. They are
1) Natural Scaffold
Blood clot
PRF
2) Artificial Scaffold
Collagen
poly glycolic acid (PGA)
polylactic acid (PLA)
poly lactic co glycolic acid (PLGA)
13. Natural scaffolds
- Good biocompatibility and bioactivity.
- Can cause discomfort to the patient due to
intentional periapical filling to induce blood clot
Artificial scaffolds
- Control over degradation rate and mechanical
properties.
- Allows for replacement with natural tissues after
undergoing degradation.
14. CASE STUDY :
Aim :
To evaluate and compare the regenerative potential of
natural autologous scaffolds (blood clot and PRF) with
artificial scaffolds (collagen and poly-lactic-co-glycolic
acid ( PLGA ) polymer) .
Materials and Methods :
- Necrotic immature permanent maxillary incisors
(with or without radiographic evidence of periapical
lesion)
15. REVASCULARISATION :
It is a new treatment method for immature necrotic permanent teeth.
It stimulates the apical development and root maturation of immature
permanent teeth. It is an alternative treatment method for the apexification.
Steps in revascularization :
under rubber dam isolation , access opening was done in teeth with #2 round
diamond bur.
Axial wall extensions were done with safe tip fissure carbide bur.
Minimal canal instrumentation was done with k-files to remove the necrotic
tissue
Canals were copiously irrigated with 2.5% sodium hypochlorite solution using a
syringe and side vented needle.
16. Triple antibiotic paste (400 mg metronidazole(bactericidal),250
mg ciprofloxacilin(bactericidal), 50 mg minocycline) was used
as the medicament for 4 weeks and the access cavity was
sealed with temporary restorative material.
Disadvantage includes the discoloration of tooth due to the
use of minocycline. The discoloration can be prevented by
the use of cefuroxime or by the application of bonding
agent in the coronal dentin to seal the dentinal tubules.
The alternative for the antibiotics includes the calcium
hydroxide insertion . But the calcium hydroxide insertion
should be limited to the cervical third of the root canal
since there are increased incidences of root fracture due to
disruption of the link between hydroxyapatite crystals and
the collagenous network in dentin.
17. After 4 weeks :
- Teeth were re-accessed under rubber dam isolation
- Triple antibiotic paste was washed out of the canal
using copious amount of 2.5% sodium hypochlorite
solution
- Canals were dried and further revascularization
procedure was carried out only if the tooth was
asymptomatic with no drainage from the canal.
18. 16 cases selected for the study divided into four groups
with each group containing four cases.
GROUP
I Blood clot
II PRF
III collagen
IV PLGA
19. GROUP I
(BLOOD CLOT)
GROUP II
(PRF)
GROUP III
(COLLAGEN)
GROUP IV
(PLGA)
Under local anesthesia
without adrenaline, a
sterile 23 gauge needle was
passed beyond the working
length and bleeding was
induced in the canal.
A tight cotton pellet was
inserted in the coronal
portion of the canal and
pulp chamber for 7-10 min
to induce clot formation in
the apical two third of the
canal.
Access cavity was sealed
with GIC.
PRF was prepared by
drawing 5 ml of venous
blood from the patient in a
dried glass test tube and
immediately centrifuging at
3000 rpm for 10 min.
Base layer of RBC
Top layer of acellular
plasma
PRF clot in the middle
The clot was then pressed
between two gauge pieces
to form a membrane.
PRF was carried to the
apical part of the canal
using the endodontic
pluggers.
Access cavity was sealed
with GIC.
Blood clot was induced in
the root canal as done in
group I .
Sterile collagen sponge
was inserted into the root
canal with the endodontic
pluggers.
Access cavity was sealed
with GIC.
Blood clot was induced in
the root canal as done in
group I .
Sterile PLGA crystals was
inserted into the root canal
with the endodontic
pluggers.
Access cavity was sealed
with GIC.
20. SCORING CRITERIA :
SCORE RADIOGRAPHIC HEALING
0 No healing / improvement from baseline
1 Fair healing / improvement from baseline
2 Good healing / improvement from baseline
3 Excellent healing / improvement from baseline
*Pre-operative intra oral periapical radiograph was taken as baseline record.
21. RESULTS :
The evaluations were done at 6 and 12 months after the
procedure and compared with baseline records.
Clinical evaluation :
- Patients were completely asymptomatic throughout the
study period with no tenderness to palpation and
percussion.
- Swelling and sinus had resolved completely and did not
reappear.
22. Radiographic evaluation :
All 16 cases showed improvement in terms of
periapical healing,periapical closure, root lengthening,
dentinal wall thickening.
23. GROUP I – BLOOD CLOT
Teeth No. 11,21 Pre-Operative After 6 months After 12 months
24. GROUP II - PRF
Tooth No. 21 Pre-Operative After 6 months After 12 months
25. GROUP III - COLLAGEN
Tooth No.21 Pre- operative After 6 months After 12 months
26. GROUP IV – PLGA
Tooth No. 21 Pre – operative After 12 months
27. COMPARATIVE EVALUATION OF PERIAPICAL HEALING :
GROUPS FAIR (%) GOOD (%) EXCELLENT (%)
I (Blood clot) 25 50 25
II (PRF) - 25 75
III (Collagen) - 75 25
IV (PLGA) 75 25 -
28. COMPARATIVE EVALUATION OF APICAL CLOSURE :
GROUPS FAIR (%) GOOD (%) EXCELLENT (%)
I (Blood clot) 25 75 -
II (PRF) - 50 50
III (Collagen) 25 25 50
IV (PLGA) 50 50 -
29. COMPARATIVE EVALUATION OF ROOT LENGTHENING :
GROUPS FAIR (%) GOOD (%) EXCELLENT (%)
I (Blood clot) 25 75 -
II (PRF) 100 - -
III (Collagen) 75 25 -
IV (PLGA) 50 50 -
30. COMPARATIVE EVALUATION OF DENTINAL WALL THICKENING :
GROUPS FAIR (%) GOOD (%) EXCELLENT (%)
I (Blood clot) 50 50 -
II (PRF) 25 75 -
III (Collagen) 25 50 25
IV (PLGA) 75 25 -
31. GROUP
PRF Rich quantities of growth factors required for
cellular proliferation,differentiation and
angiogenesis.
COLLAGEN Formation of mineralized tissues in teeth with
incomplete root development and apical
periodontitis. It also helps in stem cell
adhesion,proliferation and differentiation.
BLOOD CLOT It serves as a source of stem cells from granulation
tissue, PDL , apical papilla.
Collagen along with blood clot gives better results
due to the risk for the blood clot disintegration
PLGA Stimulates bone growth . Acts as a suitable matrix to support dental
stem cells and their differentiation to form an organized dentin/pulp
like tissue. The osteoblast will reproduce on the scaffold.
Differentiation will take place subsequently, forming the required
bone as the scaffold degrades. It breaks down into lactic acid and
glycolic acid, which are metabolised in the body and excreted as
carbon dioxide and water. This process typically occurs over a time
frame of two to six months.
32. CONCLUSION :
Revascularisation procedure is more effective and
conservative over apexification in the management of
necrotic immature permanent teeth.
PRF and Collagen are better scaffolds than blood clot
and PLGA for inducing apexogenesis in immature
necrotic permanent teeth.
