endodontic surgery and its current concepts

1. Endodontic surgery and its current
concepts
Presented by Dr Boris Saha (AMU)
Supervisor : Prof Ashok Kumar
Co supervisor : Dr Shariq Alam
Contact details ph no 9804427359 , borissaha@gmail.com

2.  Introduction
 Definition
 History
 Indication
 Contraindication
 Classification of Endo. Surgeries
 Endodontic surgical Procedures
 Post operative Instruction
 Root End preparation
 Root end Filling materials
 Regenerative Materials
 Microsurgical Techniques & Procedures
 Nanorobotics

3. Endodontic treatment has been consistently high
but failures may arise due to infection, poor access cavity
preparation, inadequate instrumentation , obturation,
missed canals and coronal leakage.
Surgical intervention is required where endodontic
treatment has failed and tooth is to be retained
rather than extracted.

5. Surgical endodontics is not a recent innovation.
Trephination and incision and drainage are being done
since ancient times.
In 11th century, first case of endodontic surgery was
performed byAbulcasis.
Root end resection (Apicectomy ) was first
documented in 1871 and apicectomy with retrograde
cavity preparation and filling with amalgam was
documented in 1890.

6. Root amputation was first introduced by Black and Inlitch in 1886 , then
was dealt by Younger (1894) and Guerini (1909)
In 1930, indications for endodontic surgery were proposed.
In 1940, Triangular flap was first described by Fischer.
Neumann and Eikan descibed Trapezoidal flap in
1940.
Semilunar incision was first described by Partsch hence it is also
known as Partsch incision.

7. 1. Need for surgical drainage
2. Failed endodontic treatment
1. Irretrievable root canal filling material
2. Irretrievable intraradicular post
3. Calcification of the pulp space
4. Procedural errors
1. Instrument fragmentation
2. Non-negotiable ledging
3. Root perforation

8. 5. Symptomatic overfilling.
6. Anatomic variations.
A. Root dilaceration.
B. Apical root fenestration.
7. Biopsy.
8. Corrective surgery.
1. Root resorptive defects
2. Root caries
3. Root resection
4. Hemi-section
5. Bi-cuspidization

9.  Poor systemic health.
 Local anatomical considerations
 Poor periodontal status.
 Short root length.
 Acute infection.
 Non restorable teeth

10.  Success of surgical treatment over non-surgical
treatment.
 Medical history
 Periodontal evaluation
 Patient’s motivation
 Informed consent
PRESURGICAL CONSIDERATION

12. I. Surgical drainage
1. Incision and drainage
2. Cortical trephination (fistulative
surgery)
II. Periradicular surgery
1. Curettage
2. Biopsy
3. Root-end resection
4. Root-end preparation and filling

13.  In most cases drainage through the canal is all
that is needed to treat the periradicular abcess
of pulpal origin but there are times, when
invasion of anatomic spaces has extended to a
point that does not allow drainage through the
tooth, and effectively remove the pus then It
becomes mandatory to incise and drain the
abcess.

14. Principles and guidelines are applied to the location and
extent of incision.
Why should one follow the principles ???
“The adherence to these principles will ensure that the
flapped soft tissues will fit snugly in their original
position and will properly cover the osseous wound site
and provide an adequate vascular bed for healing”

15. PRINCIPLES:
 1. Avoid severing vessels and nerves
 2. Make incisions far away from the surgical
area to ensure that the wound margins are
over sound bone and there is room for
adjustments when unexpected extensions
are necessary.
3. Design the flap so that there is adequate
visibility without overexposure of bone.

16. 4. The base of the flap should be the widest
portion to maintain proper circulation.
5. There should be no sharp angles on the flap
6. Vertical or oblique incision should not be
over root eminence. It is best to incise in the
trough.

17. 7. Maintain the integrity of the interdental
papillae.
8. Use sharp instruments to avoid tearing the
mucoperiosteum.
9. Be gentle with the flap.
10.Do not incise close to the gingival sulcus
while using a horizontal or semilunar
incison

18. 11. Incise in the attached gingiva for
semilunar flaps.

19. “More trauma results from short incision rather
than long incision”.

20.  Vertical incision
 Sulcular incision
 Semilunar incision
 Modified semilunar incision
 Ochsenbein-Leubke incision

21. 1. Full mucoperiosteal flaps:
(a) Triangular (one vertical releasing incision)
(b) Rectangular (two vertical releasing incisions)
(c) Trapezoidal (broad-based rectangular)
2. Limited mucoperiosteal flaps
(a) Submarginal curved (semilunar)
(b) Submarginal scalloped rectangular (Ochsenbein-
Luebke)

22. A
A . Sin g le V e r t i c a l
(T ria n g u l a r ) B
B . D o u b le V e r t i c a l
(T r a p e z oid a l) c
C . D o u b le
V e r t ic a l
( R e c t a n g u la r)
0 . S c a l lo p e d
(L u e b k e - O c h s e n b ein )

23. TRIANGULAR FLAP.
 The triangular flap is formed by a intrasulcular
incision and one vertical releasing incision.

24.  Good wound healing as there is minimal disruption
of the vascular supply to the flapped tissue,

 Ease of flap reapproximation, with a minimal number
of sutures required.
 DISADVANTAGE:
 It provides Limited surgical access because of the
single vertical releasing incision.
 Difficult to expose the root apices of long teeth (eg,
maxillary cuspids and mandibular incisors.)

25.  Additional access can be easily obtained by placement
of a distal releasing incision.
 It is recommended for maxillary incisors and
posterior teeth.
 “It is the only recommended flap design
for mandibular posterior teeth”.

27.  ADVANTAGES:
 Increased surgical access to the root apex.
 This flap design is especially useful for mandibular
anterior teeth, multiple teeth, and teeth with long
roots, such as maxillary canines.
 DISADVANTAGES:
 Difficulty in reapproximation of the flap margins and
wound closure.
 Postsurgical stabilization is also more difficult as the
flapped tissues are held in position solely by the
sutures. This results in a greater potential for
postsurgical flap dislodgment.
 This flap design is not recommended for posterior
teeth.

29.  The angled vertical releasing incisions are designed
to create a broad-based flap with the vestibular
portion being wider than the sulcular portion.
 Flap design is made on the assumption that it will
provide a better blood supply to the flapped
tissues.

30.  Since the blood vessels and collagen fibers in the
mucoperiosteal tissues are oriented in a vertical
direction, the angled vertical releasing incisions will
severe more of these structures.

31.  This will result in more bleeding, a disruption of
the vascular supply to the unflapped tissues, and
shrinkage of the flapped tissues.

32.  The submarginal or semilunar flap is formed by a
curved incision in the alveolar mucosa and the
attached gingiva.

33.  The incision begins in the alveolar mucosa extending
into the attached gingiva and then curves back into
the alveolar mucosa.
 Advantages – No advantages
 Disadvantages-
1. Poor surgical access
2. Poor wound healing
 “This flap design is not recommended for periradicular
surgery”.

34.  The submarginal scalloped rectangular flap is a
modification of the rectangular flap in which the
horizontal incision is not placed in the gingival sulcus
but in the buccal or labial attached gingiva.

35.  DISADVANTAGES:
 Vertically oriented blood vessels and collagen fibers
are severed, resulting in more bleeding and a greater
potential for flap shrinkage, delayed healing, and scar
formation.

36.  FLAP REFLECTION:
 Flap reflection is the process of separating the soft
tissues (mucosa and periosteum) from the surface of
the bone.
 The periosteal elevator is used gently to elevate the
periosteum and its superficial tissues from the cortical
plate.

37.  After reflection of the attached gingival tissues,
elevation is continued more apically lifting the
alveolar mucosa along with periosteum until
adequate surgical access is obtained.
 A thin gauze may be used for reflection to prevent
tearing of the flap.

38.  Osteotomy is the removal of some portion of the
cortical plate to expose the root end.
 Clinician should precisely locate the root end.
 A number of factors should be considered to
determine the location of the bony window.
 The angle of the crown to the root should be
assessed.

39.  When a root prominence or eminence in the
cortical plate is present, the root angulation and
position are more easily determined.
 Measurement of the entire tooth length on well-
angled radiograph and transferred to the
surgical site by the use of a sterile millimeter
ruler.

40.  When the cortical plate is intact, locate the body of
the root coronal to the apex where the bone covering
the root is thinner.
 Once the root has been located and identified, the
bone covering the root is slowly and carefully
removed with light brush strokes, working in an
apical direction until the root apex is identified.

41. 
 (1) Root structure generally has a yellowish color,
 (2) Roots do not bleed when probed,
 (3) Root texture is smooth and hard as


compared to the granular and porous
nature of bone, and
 (4) The root is surrounded by the periodontal
 ligament.

42.  Hard tissue management in endodontic surgery
involves 3 stages:
1.Trephination
2.Periradicular curretage
3. Periradicular surgery
(i) Root end resection (Apicectomy)
(ii) Root end preparation & filling

43.  Definition- It is the perforation made through the
 cortical plate or apical foramen to accomplish the
release of pressure in the periapical area from
the accumulation of exudate within the
alveolar bone.
 Indications-
 This technique is employed in cases of periapical
abcess in which there is no swelling or drainage
but much pain.

44.  Small incision is made over the periapical
region .flap is reflected and bone is
examined.
 Radiograph is taken with radiopaque marker
for confirmation. So that there is no chance of
penetration in the wrong area.

45.  Perforation of the cortical plate to accomplish the
release of pressure from the accumulation of exudate
within the alveolar bone.

46.  The treatment of choice for these patients is
drainage through the root canal system (apical
trephination) whenever possible.
 Apical trephination involves penetration of the
apical foramen with a small endodontic file and
enlarging the apical opening to a size No. 20 or
No. 25 file to allow drainage from the
periradicular lesion into the canal space.
 The decision about whether to perform apical or
cortical trephination is based primarily on clinical
judgment regarding the urgency of obtaining
drainage.

47.  PERIRADICULAR CURETTAGE:
 Involves removal of the periradicular inflammatory
tissue and is best accomplished by using various sizes
and shapes of sharp surgical bone curettes and angled
periodontal curettes.

49. Once the soft tissue lesion has been freed
along with the periphery, the bone curette
should be turned with the concave portion
toward the soft tissue and used in a scraping
manner to free the tissue from the deep walls
of the bony crypt.

50. 
 ROOT-END RESECTION (APICOECTOMY)
 Historically, many authors have advocated
periradicular curettage as the definitive
treatment in endodontic surgery without
root-end resection.
 Their rationale was to maintain a cemental
covering on the root surface and to maintain as
much root length as possible for tooth stability.

51.  These indications may be classified as,
1) Biological
2) Technical.
Biologic factors:
 Persistent symptoms,
 Persistent periradicular lesion.

52. Technical factors:
Periapical infection in teeth with…
 Radicular posts,
 Crowned teeth without posts,
 Irretrievable root canal filling materials,
 Procedural accidents.

53.  There are three important factors for the
surgeon to consider before performing a
root-end resection:
(1) Instrumentation,
(2) Extent of the root end resection,
(3) Angle of the resection.

54.  1.Instrumentation:
 Ingle et al. recommended that root-end resection
is best accomplished by the use of tapered
fissure bur or round bur in a low-speed straight
handpiece.
 Gutmann and Harrison, have suggested the use
of a high-speed handpiece and a surgical length
plain fissure bur.

55.  NOTE:
 “Plain fissure burs, at high and low speed,
produce the smoothest resected root
surface”.
“Round burs produces less heat and less
inflammation compared to others “
Cohen

56.  Earlier, it was believed that it is necessary to
resect the root at the level of healthy bone.

57. Average length of root resection is 3mm which
is considered enough to eliminate the source
of infection.
 however surgeon must evaluate the patient on
an individual basis.
1.Visual and operative access to the surgical site
2.Anatomy of the root (shape, length,
curvature).
3.Number of canals and their position in the
root

58. 4. Need to place a root-end filling surrounded
by solid dentin.
5. Presence and location of procedural error
6. Presence and extent of periodontal defects.

59.  NOTE:
“Conservation of tooth structure during
root-end resection is desirable; however,
conservation should not compromise the
goals of the surgical procedure”.

60. It should be 30 ° -45 ° from the
line perpendicular to the long
axis of the tooth facing toward
the buccal or facial aspect of the
root.
The purpose is to provide
enhanced visibility to the root end
and operative access to
accomplish a root end
preparation.

61.  NOTE:
 Recent literature states that beveling of root end
results in opening of dentinal tubules on the
resected root surface that may communicate with
the root canal space and result in apical leakage,
even when a root end filling has been placed.

62. The purpose of a root-end preparation
in periradicular surgery is to create a
cavity to receive a root-end filling.
It is performed by the use of small round or
inverted cone burs and straight low-speed
handpiece.
It should be done parallel to the long axis of
the root.

63. Root-end
filling

64.  The purpose of a root-end filling is to establish a
seal between the root canal space and the periapical
tissues.
 Suitable root-end filling material should be,
(1) Able to prevent leakage of bacteria and their
biproducts into the periradicular tissues,
(2) Nontoxic & Noncarcinogenic,
(3) Biocompatible with the host tissues,
(4) Insoluble in tissue fluids,
(5) Dimensionally stable,
(6) Unaffected by moisture during setting,
(7) Easy to use

65. Numerous materials have been suggested
for use as root-end fillings, including:
 Gold Foil
 Amalgam,
 Gutta-percha,
 Glass ionomers,
 Composite resins,
 Carboxylate cements,
 Zinc phosphate cements,
 Zinc oxide–eugenol cements
 MTA

67.  Several authors have compared the effects of
continuous and interrupted suture techniques.
 Their findings indicate that the interrupted suturing
technique provides better flap adaptation than does
the continuous technique and, therefore, is the
recommended technique, and the most commonly
used, for endodontic surgery.

69. 1. Ask not to drink alcohol or use any form of tobacco.
2..Ask not to lift up the lip or pull back the cheek to
look at where surgery was done. This may pull the
sutures and cause bleeding.
3.Alittle bleeding from the surgical site is normal.
This should only last for a few hours. There may be
little swelling of the face. This should only last for a
few days.

70. done. Leave it on for 20 minutes and take it off for
20 minutes. Do this for 6 to 8 hours.
5. After 8 hours, the ice bag should not be used. The
day after surgery, warm saline gargle. Do this as
often as possible for the next 2 to 3 days. Advice for
warm saline gargle.
7.Rinse the mouth with 1 tablespoon of chlorhexidine
mouthwash two times a day, once in the morning and
once at night for 5 days.
8. Recall for removal of sutures after 7 days,

72.  Advances in technology including specially
designed instruments, improved root end
filling materials, and along with a more
thorough understanding of the biology of
wound healing, have all contributed to the
contemporary concept of “Microsurgical
Endodontics.
INTRODUCTION

73. magnification Illumination instrumentation

74.  Illumination and magnification are provided by the
surgical operation microscope
 With bright, focused light on a × 4 to × 31 magnified
surgical site, the surgeon can see every detail of the
apical structures and can execute treatment more
precisely.
 additional benefit, the magnification has also
resulted in smaller osteotomies

75.  instrumentation. Working in a magnified
surgical site required a different set of
surgical instruments such as Ultrasonic tips,
condensers, pluggers, curettes, and mirrors
were reduced in size to comfortably fit into
an osteotomy no larger than 5 mm to gain
access to the canals.

76.  Kim and Kratchman classified periradicular lesions into
categories A–F. Lesion

78.  The most frustrating aspects of microscopic surgery is the
correct positioning of the dental operating microscope relative to
the patient and operative field
 The patient is positioned in a supine to slightly Trendelenberg
attitude so that the surgical osteotomy site is most superior in
the operating field.
 The patient can then be stabilized for comfort in this new
position using rolled-up surgical towels, “donut” style headrests
or memory foam pillows
 The surgeon then takes a position of 11–12 O’clock orientation

79.  The operator’s chair height is adjusted so that the angle
formed between the thigh and lower part of the foot is a
minimum of 90°, and the spine is comfortably straight
 The patient’s chair is then raised or lowered so that the
surgeon can maintain his or her elbows close to his body,
passively bent at a neutral 90°.
 Once positioned, the surgeon’s arms and hands should
not deviate from the core-centric position; this affords the
greatest dexterity and precise micro-control while limiting
fatigue and strain trembling.
 The microscope is last positioned with the line of sight axis
perpendicular to the soft tissue field of the intended flap,
and the binocular eyepieces adjusted to a comfortable
height relative to the operator

80.  Inclinable optics allow for the microscope to assume
different vertical attitudes relative to 90°, and a shift of
as little as 20° in either direction will enable the surgeon
to look past the head of the handpiece to the end of a
burr, or use direct vision to examine a resected root
end.

82.  The design and manufacturer of the first generation of
micro-instruments are Dr. Garry Carr
 Examination instruments are a mirror, periodontal
probe, explorer, and micro explorer.
 Incision and elevation instruments-15 and 15 C blade,
mini scalpels and blades, Periosteals Molt 9, Prichard
PPR3, PPB user, P145S, P9HM, P4 elevators
 Curettage instruments - mini jacquette 34/35 scaler, a
Columbia 13–14, and minimolten and miniendodontic
curettes.

83.  Inspection Instruments-Micro-Mirrors. Retrofilling carrier
and plugging instruments.
 Osteotomy instruments - The Impact Air 45 handpiece,
The H 161 Lindemann Bone Cutting Bur.

84.  Suturing instruments - Laschal microscissors, or any
small-beaked scissors, and the castroviejo needle
holder.
 Tissue retraction instruments - Kim-Pecora tissue
retractors, Rubinstein retractors, Prichard retractors.
 Miscellaneous instruments are a small ball burnisher
and a bone file, microrongeur

85.  1st designed by Dr. Garry Carr are known as Carr tips or CTs.
 1/4 mm in diameter and about 1/10 the size of a conventional
microhead handpiece
 The CT 1 and CT 5 tips are used mainly for maxillary and
mandibular anterior teeth.The CT 2 and CT 3 have a double angle
to facilitate workin posterior teeth.

86.  The Kim surgical (KiS) ultrasonic tip is the next
generation microsurgical tips.
 It is coated with zirconium nitride and has an irrigation
port near the tip rather than the shaft (as with CTs). The
cutting tip is of 3 mm.
 These advanced tips cut faster and smoother and cause
fewer microfractures because of the improved
positioning of the irrigation port.

87.  Long-acting anesthetic agent such as
bupivicaine should be given to obtain a
sustained level of anesthesia beyond the
duration of the surgery.
 Once the regional anesthesia has been
achieved, then a local infiltration of lidocaine
1:50,000 epinephrine is injected over the
intended flap extent, concentrating the bulk of
the infiltration over the surgical site

88.  Presurgical : Inject two carpules of 1:50,000 epinephrine containing
local anesthetic, e.g. 2% xylocaine, into multiple infiltration sites
buccal/lingual and palatal throughout the entire surgical field.
 Surgical : Place an epinephrine pellet into the bone crypt followed by
dry sterile cotton pellets until the crypt is filled. Apply pressure for 2
min, then apply cotton pellet soaked with ferric sulfate solution. ferric
sulfate deposits must be carefully and thoroughly removed by a saline
flush, as they are a major irritant to the tissues if left in-situA large
osteotomy site is filled with freshly mixed calcium sulfate paste.
Although the paste is not designed for hemostasis per standard error,
it is a very effective agent for hemostasis for a large bone crypt.
 Postoperative phase Moist gauze compresses should be applied to the
tissues before and after suturing

89.  The semilunar incision, the most popular flap design technique
with anterior teeth, is no longer recommended because of
inadequate access and scar formation
 The removal of sutures is done within 48–72 h
 New suture materials are monofilament, gauge 5 × 0 or 6 × 0 to
provide rapid healing
 The papilla base incision has been developed to prevent loss of
interdental papilla height with sulcular incisions
 Flap retraction during the surgery is facilitated by making a
resting groove in the bone, especially during mandibular
posterior surgery to ensure retraction

90.  Two simple techniques: interrupted suturing
and sling suturing are recommended.
Usually the interrupted suture technique is
used for the vertical releasing incision, and
the sling suture technique is used for the
interproximal and sulcular incisions

92.  Once the surgeon is sure of the exact location of the apex, the
cortical bone is removed slowly and carefully with copious water
spray under low magnification
 The H 161 Lindemann bone cutter and the Impact Air45
handpiece are best suited for creating an osteotomy.
 The bone cutter bur is specially designed to remove the bone
while minimizing the frictional heat.
 The advantage of the Impact Air 45 handpiece is that water is
directed along the bur shaft, while air is ejected out of the back
of the handpiece. This creates less splatter than conventional
handpieces and decreases the chance of emphysema and
pyemia.

93.  The smaller the osteotomy, the faster the healing. For
instance, a lesion smaller than 5 mm would take on
average 6.4 months
 With the microsurgical techniques, the size of the
osteotomy is significantly smaller, just 3–4 mm in
diameter. This is just larger than the ultrasonic tip of 3
mm in length, yet allows the tip to vibrate freely within
the bone cavity

94.  Once the lesion and the root tip are exposed, Columbia #13 and
#14 curettes and Molten or Jacquette 34/35 curettes are used to
completely remove the granulation tissue under medium
magnification (×10 to × 16). Large curettes, such as a 33 L spoon
excavator or a #86 Lucas bone curette are suitable for the
enucleation of large lesions.
 The Jacquette 34/35 scaler allows efficient removal of tissue from
the junction of the bone crypt and the root

95.  Von Arx et al.[13] recommended a resection of the
apical 3 mm, followed by the preparation of a
root-end cavity 3 mm deep, making the “therapeutic
length” 6 mm.
 Hess found out that that resecting 1 mm off the
apex reduces 52% of apical ramifications and 40%
of lateral canals; 2 mm off the apex reduces 78% of
apical ramifications and 86% of lateral canals.
Three millimeters off the apex reduces 93% of
apical ramifications and 98% of lateral canals.[

96.  There are, however, 2 notable exceptions to this
rule. First, if the level of resection is such that it
leaves a root geometry that is significantly curved at
that level, then the root end preparation will be
compromised. Hence, the preparation will be
shallower than required because of the tip’s impact
on the curve or, if forced longer, can, in fact,
perforate the external root surface
 The other exception occurs when the root in
question has undergone a resorptive process and is
shorter than normal
 Comparison of the root length of the contralateral
tooth can assist in determining how much more of
the apex needs to be removed if any.

97.  With the traditional rotary bur, the steep bevel angle of 45–
60° was recommended
 The purpose of this steep bevel was simply for access and
visibility.
 In fact, beveling causes significant damage to the tissue
structures, that is, buccal bone and root
 (1) The amount of leakage increased as the slope of the
bevel increased; (2) increasing the depth of the retrograde
filling decreased the micro leakage; and (3)
optimum/minimum depths for the retrograde were as
follows: 0° =1 mm, 30° =2.1 mm, 45° =2.5 mm.

99.  A complete and critical inspection of the resected root surface requires
staining of the surface with a contrasting medium, such as methylene
blue that stains the PDL and pulp tissues selectively.
 After a few seconds, the root and the bone crypt are rinsed with
isotonic saline to remove the excess stained then dried with a Stropko
irrigator/drier.
 The stained area can then be examined under the microscope
 If the entire root tip has been resected, the PDL appears as an
unbroken line around the root surface. A partial line indicates that only
part of the root has been resected
 If no definable line can be seen, it probably means that only the bone,
and not the root, has been stained. The staining also helps to
distinguish craze lines from microfractures; microfractures stain but
craze lines do not

100.  An isthmus is defined as a narrow strip of land connecting two larger land
masses or a narrow anatomic part or passage connecting two larger structures
or cavities
 Type I was defined as either two or three canals with no noticeable
communication
 Type II was defined as two canals that had a definite connection between the
two main canals.
 Type III differs from the latter only in that there are three canals instead of two.
Incomplete C-shapes with three canals were also included in this category.
 When canals extend into the isthmus area, this was named Type IV.
 Type V was recognized as a true connection or corridor throughout the section.

101.  Incidence At the 3-mm level from the original
apex, 90% of the mesiobuccal roots of
maxillary first molars have an isthmus, 30%
of the maxillary and mandibular premolars,
and over 80% of the mesial roots of the
mandibular first molars have one.[

102.  The ideal root-end preparation can be defined as a Class I
cavity at least 3 mm into root dentine, with walls parallel to
and coincident with an anatomic outline of the root canal
space.
 Problems encountered with traditional root end preparation
1) Access to the root-end is difficult, especially with limited
working space 2)There is a high risk of a perforation of the
lingual root-end or cavity preparation, when it does not
follow the original canal path 3) insufficient depth and
retention of the root-end filling material4) root-end
resection procedure exposes dentinal tubules 5) Necrotic
isthmus tissue cannot be removed

103.  The USREP procedure is carried out under the microscope at
low to middle magnifications (×4 to × 16)
 In single canal roots, the tip is placed into the center of the canal
space.
 The tip is energized, with enough coolant delivered through the
tip to cool and flush the preparation site.
 The tip is allowed to seek passively its way down the canal, and
this will happen readily if Gutta-percha is in the canal.

 Any high-pitched squeal from the tip indicates either binding in a
small, uninstrumented canal, or that the tip is traversing
off-angle.

104.  The preparation is complete when the full depth of the tip
is reached, usually 3 mm.
 In a root with multiple canals and an isthmus joining them
(i.e. the MB root of the maxillary first molar), the two
canals (MB1 and MB2) are prepared separately to
establish the correct angulation of the preparation, then
the isthmus connecting them is prepared at the same
angle, but caution should be exercised not to overheat the
tip or the root end by prolonged dry cutting
 Maddalone and Gagliani showed overall healing of 92.5%
they used 4 loupes, ultrasonic tips and Super EBA
root-end fillings.[

105.  As the ultrasonic unit is activated, Gutta-percha
is thermo plasticized and comes out of the
preparation in long strings.

106. Caution: this instrument must be used
without excessive pressure, at the lowest
possible efficient power setting.

107.  After the retro preparation is completed, the
prepared cavityis inspected with a micro
mirror at a high magnification (×16 to × 25).

108.  Stropko instrument allows reliable and
successful irrigation and drying of a prepared
canal

109.  The ideal root-end filling material should be
biocompatible, bactericidal, or at least
bacteriostatic; should be neutral to
neighboring tissues, and should provide
excellent sealing. Furthermore, it should
promote regeneration of the original
tissues.

110.  Castor Oil polymer (obtained from Riccinus communis , biopolymer
chain of fatty acids ) decreased dye penetration compared to mta
 Bioaggregate (modification of mta containing ceramic )
 Biodentine (calicum silicate based )
 Epoxy resin & portland cement
 Capasio (calcium phospho aluminosilicate based cement)
 Endobinder (new calcium aluminate cement)
 Generex A ( calcium slicate based by dentsply)
 ceramicerete (hydoxyapatite +cerium oxide )
 Endosequence Bc
 iRootBP plus (water based bioceramic )

114.  CONCLUSION :
 During the last 20 years, endodontics has
encountered dramatic shift in the use of
periradicular surgery
 Endodontic surgery has now evolved into
endodontic microsurgery. By using state-of the-art
equipment, instruments and materials that match
biological concepts with clinical practice, it can be
believed that microsurgical approaches produce
predictable outcomes in the healing of lesions of
endodontic origin

115.  Ananad S, Soujanya E, Raju A, Swathi A. Endodontic microsurgery:
An overview. Dent Med Res [serial online] [cited 2018 Mar 27];3:31-
7. Available from:
http://www.dmrjournal.org/text.asp?2015/3/2/31/159172
 https://www.aae.org/specialty/wp-
content/uploads/sites/2/2017/07/ecfefall2010final.pdf