management of non vital open apex roots/ orthodontic course by indian dental academy

MANAGEMENT
OF
NON –VITAL
WIDE OPEN APEX

MANAGEMENT OF NON VITAL WIDE OPEN APEX
INTRODUCTION
DEFINITIONS
Open apex (Incomplete Rhizogenesis)
Induction of apical healing
Apexogenesis
Maturogenesis
Apexification
Apexigenesis
One-visit apexification
ROOT DEVELOPMENT
Stages of root development
By Nolla
By Cvek
CAUSES OF OPEN APICES
Pulpal injury in teeth with developing roots
TYPES OF OPEN APICES
1. Non blunderbuss
2. Blunderbuss
PROBLEMS ASSOCIATED WITH INCOMPLETE RHIZOGENESIS
DIAGNOSIS AND CASE ASSESSMENT
APEXOGENESIS

MATUROGENESIS
METHODS FOR THE TREATMENT OF TEETH WITH AN
INCOMPLETELY FORMED APEX (OPEN APEX)
I. Blunt end or rolled cone (customized cone)
II. Short fill technique
IV. Apexification

INTRODUCTION
The golden rule in the practice of endodontology is to debride and
obturate the canals as efficiently and three dimensionally as possible in an
amount of time and appointments that are reasonable to the patient. It is
reasonable to assume that most endodontists have achieved the necessary
skills to manage predictably and comfortably most of the endodontic cases
in their practices. However, there are a group of patients that defy
predictable routine treatment.
The completion of root development and closure of the apex occurs up to
3 years after eruption of the tooth (1). The treatment of pulpal injury during
this period provides a significant challenge for the clinician. Depending
upon the vitality of the affected pulp, two approaches are possible
apexogenesis or apexification Article 46 Mary Rafter
As always, success is related to accurate diagnosis and a full understanding
of the biological processes to be facilitated by the treatment. Article 46 Mary
Rafter
The group of patients who present with non vital immature apical formation,
requires a specially tailored treatment plan, different from other patients,
oftentimes requiring much more than 1 year to complete, depending on the
degree of apical immaturity.

Before 1966 the clinical management of a “Blunder buss” canal usually
required a surgical approach for the placement of an apical seal into the
often fragile and flaring apex. Treatment was complicated when patient
management required conscious sedation or general anaesthesia, especially
with children.
Apexification with calcium hydroxide (Ca(OH)2 has proven to be a reliable
and most welcome addition to the therapeutic armamentarium since
Frank described it in 1966. Article 33 Howard S. Selden (2002)
This process of natural apical closure is more biologic and less traumatic
than the classic technique of apicoectomy and obturation of the apex with
gutta percha or a retrograde amalgam

DEFINITIONS
Open apex (Incomplete Rhizogenesis)
Refers to the absence of sufficient root development to provide a
conical taper to the canal and is referred to as a blunderbuss canal (this
means that the canal is wider toward the apex than near the cervical area)
Franklin S. Weine (6th
edition 2004).
Induction of apical healing
Defined as apical closure through formation of mineralized tissue and
repair of the periapical tissues.
Apexogenesis
Apexogenesis is 'a vital pulp therapy procedure performed to encourage
continued physiological development and formation of the root end' (2).
Maturogenesis
has been defined as physiologic root development, not restricted to the
apical segment. The continued deposition of dentin occurs throughout
the length of the root, providing greater strength and resistance to
fracture. Article 34 Rebeca Weisleder and Claudia R. Benitez
Apexification
. Apexification is defined as 'a method to induce a calcified barrier in a root
with an open apex or the continued apical development of an incomplete
root in teeth with necrotic pulp' (2).
Apexigenesis

One-visit apexification
Defined as the the non-surgical condensation of a biocompatible material
into the apical end of the root canal.
Morse et al. 1990

ROOT DEVELOPMENT
Root development begins when enamel and dentin formation has reached the
future cementoenamel junction. At this stage the inner and outer enamel
epithelium are no longer separated by the stratum intermedium and stellate
reticulum, but develop as a two layered epithelial wall to form Hertwig's
epithelial root sheath. When the differentiation of radicular cells into
odontoblasts has been induced and the first layer of dentin has been laid
down, Hertwig's epithelial root sheath begins to disintegrate and lose its
continuity and close relationship to the root surface. Its remnants persist as
an epithelial network of strands or tubules near Hertwig's epithelial root
sheath is responsible for determining the shape of the root or roots.
The epithelial diaphragm surrounds the apical opening to the pulp and
eventually becomes the apical foramen. An open apex is found in the
developing roots of immature teeth until apical closure occurs approximately
3 years after eruption the external surface of the root

STAGES OF ROOT DEVELOPMENT - M. Cvek
According to the width of the apical foramen and the length of the root,
Cvek has classified 5 stages of root development.
Stage 1
Teeth with wide, divergent apical opening and a root length estimated
to less than ½ of the final root length.
Stage 2
Teeth with wide divergent apical opening, and a root length estimated
to ½ of the final root length.
Stage 3
Teeth with wide divergent apical opening and a root length estimated
to 2/3rd
of the final root length.
Stage 4
Teeth with wide open apical foramen and nearly completed root
length.
Stage 5
Teeth with closed apical foramen and completed root development.

STAGES OF ROOT DEVELOPMENT
A. less than half of the final root length
B. half of the final root length
C. two third the final root length
D. nearly completed root length
E. closed apical foramen and completed root development

CAUSES OF OPEN APICES
1. Incomplete development
The open apex typically occurs when the pulp undergoes
necrosis as a result of caries or trauma, before root growth and development
are complete (i.e. during stages 1-4)
Some other causes of incomplete development are
dens in – dente
dentin dysplasia (type II)
An open apex can also occasionally form in a mature apex (stage 5) as a
result of
2. Extensive apical resorption
due to orthodontics, periapical pathosis or trauma
3. Root end resection
during periradicular surgery
4. Over-instrumentation

PULPAL INJURY IN TEETH WITH DEVELOPING ROOTS
Unfortunately traumatic injuries to young permanent teeth are not
uncommon and are said to affect 30% of children (3). The majority of these
incidents occurs before root formation is complete (4) in the 8 to 12 year age
range and most commonly involve maxillary anterior teeth. These injuries
often result in pulpal inflammation or necrosis and subsequent incomplete
development of dentinal wall and root apices.
The root sheath of Hertwig is usually sensitive to trauma but because of the
degree of vascularity and cellularity in the apical region, root formation can
continue even in the presence of pulpal inflammation and necrosis (5, 6).
Because of the important role of Hertwig's epithelial root sheath in
continued root development after pulpal injury, every effort should be made
to maintain its viability. It is thought to provide a source of undifferentiated
cells that could give rise to further hard tissue formation. It may also protect
against the ingrowth of periodontal ligament cells into the root canal, which
would result in intracanal bone formation and arrest of root development (7).
Complete destruction of Hertwig's epithelial root sheath results in cessation of normal
root development. This does not however mean that there is an end to deposition of hard
tissue in the region of the root apex. Once the sheath has been destroyed there can be no
further differentiation of odontoblasts. However, hard tissue can be formed by
cementoblasts that are normally present in the apical region and by fibroblasts of the
dental follicle and periodontal ligament that undergo differentiation after the injury to
become hard tissue producing cells.

TYPES OF OPEN APICES
These can be of two configurations
NON BLUNDERBUSS
Broadly opened apex (Cylinder – shaped root canals).
BLUNDERBUSS
Funnel shaped apex (Apical opening can be wider than the
coronal root canal orifice (inverted root canal conicity)
Non Blunderbuss
-the walls of the canal may be parallel to slightly convergent as the canal
exits the root
-the apex, therefore can be
broad (cylinder shaped) or
tapered (convergent)
Blunderbuss
-The word ‘blunderbuss’ basically refers to an 18th
century weapon with a
short and wide barrel. It derives its origin from the Dutch word
‘DONDERBUS’ which means ‘thunder gun’.
- The walls of the canal are divergent and flaring, more especially in the
buccolingual direction
- The apex is funnel shaped and typically wider than the coronal aspect of
the canal.

management of non vital open apex roots/ orthodontic course by indian dental academy

PROBLEMS ASSOCIATED WITH NON VITAL IMMATURE APEX
• Large open apices
- convergent
- parallel
- divergent
• Thin dentinal walls
- which are susceptible to fracture before, during or after treatment
• Frequent periapical lesions
- with or without associated apical resorption
• Short roots
- thus compromising crown-root ratio
• Fractures of crown
- compromising esthetics especially in the anterior region
- necessitating post endodontic rehabilitation of both crown and root
• Discoloration in long standing cases

DIAGNOSIS AND CASE ASSESSMENT
The importance of careful case assessment and accurate pulpal diagnosis in
the treatment of immature teeth with pulpal injury cannot be
overemphasized. Clinical assessment of pulpal status requires a thorough
history of subjective symptoms, careful clinical and radiographic
examination and performance of diagnostic tests.
In many instances, the patients symptoms are pain, swelling or the
appearance of a fistula, and the tooth may be slightly mobile.
An accurate pain history must be obtained. The duration and character of the
pain and aggravating and relieving factors should be considered. Duration of
pain may vary but pain that lasts for more than a brief period (a few seconds)
in a tooth with a vital pulp has been thought to be indicative of irreversible
pulpitis. When pain is spontaneous and severe, as well as long lasting, this
diagnosis is almost certain. If the pain is throbbing in character and the tooth
is tender to touch, pulpal necrosis with apical periodontitis or acute abscess
is likely. Confirmation from objective tests is necessary. These include
visual examination, percussion testing and thermal and electric pulp testing.
The presence of a swelling or sinus tract indicates pulpal necrosis and acute
or chronic abscess respectively. Tenderness to percussion signifies
inflammation in the periapical tissues. Vitality testing in the immature tooth
is inherently unreliable as these teeth provide unpredictable responses to
pulp testing. Prior to completion of root formation, the sensory plexus of
nerves in the subodontoblastic region is not well developed and as the injury
itself can lead to erratic responses (9) over reliance on the results of clinical
tests of pulp vitality, particularly by the use of electric pulp testing devices,
is not recommended (10). Radiographic interpretation can be difficult. The

radiograph may show periapical zone of radiolucency. A radiolucent area
normally surrounds the developing open apex of an immature tooth with a
healthy pulp. It may be difficult to differentiate between this finding and a
pathologic radiolucency resulting from a necrotic pulp. Comparison with the
periapex of the contralateral tooth may be helpful.
Unfortunately, it has not been possible to establish a close correlation
between the results of these individual tests and the histological diagnosis
(11 13) but it is hoped that by combining the results of the history,
examination and diagnostic tests, an accurate clinical diagnosis of pulpal
vitality can be made in most cases. When the pulp is deemed vital,
apexogenesis techniques can be attempted. A necrotic pulp condemns the
tooth to apexification.
LASER DOPPLER FLOWMETRY – A POTENTIAL AID TO
VITALITY TESTING AND PULP REVASCULARIZATION
A particularly difficult situation occurs following damage to the young
permanent tooth with an open apex. Revascularization is a possibility and is
highly desirable not only to maintain an infection free pulp space, but to
allow the tooth to continue to develop and strenghthen. On the other hand if
pulp vitality is lost, the resultant infection will initiate an inflammatory
resorption which can result in tooth loss in an alarmingly short time.
Unfortunately current sensitivity tests are poor indicators of
revascularizaiton, with the result that many pulps which were successfully

undergoing revascularization are removed unnecessarily due to the
seriousness of allowing a pulp to become necrotic with subsequent infection
and inflammatory resorption
Revascularization if highly desirable for a number of reasons.
Maintenance of vitality ensures a bacteria free pulp space and thus
inflammatory resorption is avoided.
The expense and danger of procedural accidents of endodontic therapy are
also avoided.
In addition, because tooth development continues, the possibility of post
treatment fracture due to thin, weakened dentinal walls is reduced.
In traumatized young permanent teeth, an objective, reliable test of the blood
supply to the pulp, would enable the clinician to accurately differentiate
between a pulp which is regaining its vitality and one which is becoming
necrotic. Early treatment decisions could then be made, herby reducing tooth
mortality.
Laser Doppler flowmetry is an objective test of the presence of moving red
blood cells within a tissue, which has been reported to be effective in the
detection of tooth pulp vitality as well.
Laser Doppler flowmeters, have several advantages to clinical use for pulp
resting in dentistry. They are objective, directly measure blood flow and do
not rely on sensory nerve response. Furthermore the procedure is completely
painless and should be reliable in teeth with immature apices.

50. Mesaros SV, Trope M,
In a case presented by Mesaros SV, Trope M the laser Doppler Flow meter
was utilized, and found to be more effective than CO2, ice in assessing the
occurrence of revascularization.
An eight year old child severely luxated both maxillary central incisors.
While only one of the incisors was weakly responsive to CO2 ice at 76 days
after replantation, the laser Doppler flowmeter indicated that
revascularization was occurring in both teeth at a much earlier time. Because
of the laser Doppler readings endodontic treatment was not initiated and the
teeth developed normally.
On average, the blood flow signal was 42.7% lower from teeth with necrotic
pulps compared to vital pulp measurements.

APEXOGENESIS
Apexogenesis involves removal of the inflamed pulp and the placement of
calcium hydroxide on the remaining healthy pulp tissue. Traditionally this
has implied removal of the coronal portion of the pulp. However, the depth
to which the tissue is removed should be determined by clinical judgment.
Only the inflamed tissue should be removed, but the difficulty in assessing
the level of inflammation is widely acknowledged. However a number of
investigators have demonstrated that, following mechanical exposures of the
pulp that were left untreated for up to 168 h, inflammation was limited to the
coronal 2-3 mm of the pulp (14). This has led to the development of the so-
called Cvek or shallow pulpotomy in which only the most superficial pulp is
removed. The goals of apexogenesis, as stated by Webber (15) are as
follows:
Sustaining a viable Hertwig's sheath, thus allowing continued development
of root length for a more favorable crown-to-root ratio.
Maintaining pulpal vitality, thus allowing the remaining odontoblasts to lay
down dentine, producing a thicker root and decreasing the chance of root
fracture.
Promoting root end closure, thus creating a natural apical constriction for
root canal filling.
Generating a dentinal bridge at the site of the pulpotomy. While the bridging
is not essential for the success of the procedure, it does suggest that the pulp
has maintained its vitality.

MATUROGENESIS
Although vital pulp capping and pulpotomy procedures of cariously exposed
pulps in mature teeth remain controversial, it is university accepted that vital
pulp therapy is the treatment of choice for immature teeth (incompletely
developed apices). Whenever a pulp exposure occurs in an immature tooth,
it is appropriate to use a clinical technique that preserves as much vital pulp
as possible. This step enables continued physiologic dentin deposition and
complete root development.
We would like maturogenesis to become the accepted term to use when
dealing with the treatment of immature teeth with vital pulps.
Matruogenesis shows a concern not only for a wide open apex
(apexogenesis) but also for roots having very thin and weak walls.
These teeth should be treated with total root development as the main
concern so that sufficient root strength can be attained to protect
against subsequent root fracture. Article 34 Rebeca Weisleder and
Claudia R. Benitez
The total time for achievement of the goals of the apexogenesis ranges
between 1 and 2 years depending on the degree of tooth development at the
time of the procedure. The patient should be recalled at 3-monthly intervals
in order to determine the vitality of the pulp and the extent of apical
maturation. If it is determined that the pulp has become irreversibly inflamed
or necrotic, or if internal resorption is evident, the pulp should be extirpated
and apexification therapy initiated.

METHODS FOR THE TREATMENT OF TEETH WITH AN
INCOMPLETELY FORMED APEX (OPEN APEX) AND A
NECROTIC PULP
55. Treatment of injured teeth with necrotic pulps and incomplete
apical development. Enrique Basrani
According to Enrique Basrani ,
In teeth that have not completed apical development, that anatomy of the
root canals walls may appear as follows.
The apical walls are convergent
The apical walls are parallel
The apical walls are divergent
When an apical stop is present in teeth with convergent apical walls the root
canal is obturated by standard techniques.
In teeth with parallel apical walls, the obturation techniques are called single
cone and inverted cone
In teeth with divergent apical walls, the technique uses an alkaline paste

According to Morse et al there are at least 5 methods of treating a
tooth that has a necrotic pulp and an open apex. These methods are
1. A customized cone (Blunt end, rolled cone)
filling the root canal with the large (blunt) end of a gutta percha cone
or customized gutta percha cones with a sealer.
2. A short fill technique
Filling the root canal well short of the apex (before the walls have
diverged) with gutta percha and sealer or zinc oxide eugenol (ZOE) alone.
3. Periapical surgery (with or without a retro grade seal)
Filling the root canal with gutta percha and sealer as well as possible
and then performing periapical surgery with or without a reverse seal.
4. Apexification (Apical closure induction)
Inducing apical closure by the formation of an apical stop [Calcium
hydroxide, Ca(OH)2) is generally used)] against which a permanent root
canal filling can subsequently be inserted.
5. One visit apexification
placing a biologically acceptable substance in the apical portion of the
root canal (Dentinal chips or tricalcium phosphate have been used) thus
forming an apical barrier. This is followed by filling the root canal with
gutta percha and sealer.

I. CUSTOMIZED CONE (BLUNT END OR ROLLED CONE)
The immature canal is complicated by a gaping foramen. The apical
opening is either
i. A non constructive terminus of a tubular canal (or)
ii. A flaring foramen of a “Blunderbuss” shape.
If apexification fails or is inappropriate special methods must be used to
obturate the canals without benefit of the constrictive foramen serving as a
confining matrix against which to condense.
Complete obturation requires the use of the largest gutta percha points
blunted or customized (“tailor made”) to fit the irregular apical stop or
barrier.
1. blunted points
2. inverted point technique
3. apical impression technique
-by heat
-by chemical
4. rolled cone
-by heat
-by chemical
5. thermoplasticized gutta percha
Cold lateral compaction is not the technique of choice because
1. The resistance of the canal walls for lateral pressure is reduced in
immature teeth.

2. Greater bulk of gutta percha requires an even greater force to
deform.
3. Gutta percha in seldom used sizes, can become brittle in storage and
requires even greater pressure to deform.
Warm gutta percha techniques are best suited for filling immature canals
and apices.
Tubular canals
SELECTION OR PREPARATION OF TRIAL POINT
The large tubular canal with little constriction at the foramen may best
be filled with
1. Blunted Points:
“Coarse” primary gutta percha cone that has been blunted by
cutting off the tip.
2. Tailor - made gutta percha roll/custom cone.
If the tubular canal is so large that the largest gutta percha point
is still loose in the canal; a tailor made point must be used as ‘a primary
point’.
This point may be prepared by
i. Heating
- a number of heated, coarse, gutta percha points are
arranged butt to tip, butt to tip on sterile glass slab.
- Points are rolled with spatula into rod shaped mass.
- By repeated heating and rolling, the roll of gutta percha
is formed to approximate size of canal to be filled.No
voids should exist in mass.

- The roll must be chilled with a spray of ethyl chloride
or ice water to stiffen the gutta percha before it is filled
in the canal.
- If it goes to full depth easily but is too loose, more gutta
percha must be added.
- If it is only slightly too large, the outer surface of the
gutta percha can be softened by flash heating over the
flame (or) flash dipping the point in chloroform,
eucalyptol, or halothane and the roll forced to proper
position. By this method, an internal impression of the
canal is secured
- It is dipped in alcohol to stop the action of this solvent.
Some shrinkage may alter the final impression and any compaction
before the solvent has evaporated will permit the point to continue to flow
under pressure.
Development of custom cone (From cohen)
- Two or more cones (either standardized, non
standardized, or a combination of the two) are chosen,
depending on the shape of the canal.
- The cones are softened with a light amount of heat until
they become tacky and adhere to each other.
- The cones are rolled and fused together between two
glass slabs to the desired shape and taper. Angle of the
top slab to the bottom slab determines the shape or
taper of the canal, whereas the amount of pressure on

the slab determines the thickness of the cone at any
point along its length.
- Finally, the apical portion of the cone is softened, either
with chemicals or heat, and adapted to the irregular
shape of the apical portion of the canal.
- Subsequent canal obturation can be with either lateral
or vertical compaction.

ii. Chemically plasticized cold gutta percha
A modification of the lateral compaction technique involves the use of
a solvent to soften the primary gutta percha point in an effort to ensure that it
will better conform to the aberrations in apical canal anatomy. This is a
variation of a very old obturation method, the so called Callahan – Johnston
technique.
Callahan – Johnston technique
This technique was first promulgated by Callahan in July of 1911. It
used a mixture of chloroform, rosin, and gutta percha. The problem with the
original technique centred around the use of too much of the chloroform
solvent, which resulted in a 24% decrease in volume in vitro. The
chloroform had evaporated leaving powdered guttta percha.
(In addition to Callahan Johnston technique) from Weine, 6th
Edition.
Partially dissolved gutta percha
Callahan and Johnston suggested techniques using solvents with gutta
percha to fill canals. The solvents were chloroform or oil of eucalyptol,
which were placed into the canal with a syringe, and then cones of gutta
percha were plunged into the solvent. From the evaporation of the solvent
and dissolving of the soluble gutta percha, a thick creamy mass developed,
which solidified to form a canal filling.
Disadvantages

Subsequent studies revealed that a considerable amount of contraction
developed in the filling after solidification. This dimensional change
amounted to as much as 7% which could possibly destroy the apical seal.
Other studies indicated that the solvents used were more irritating to
periapical tissues than were most root canal sealers. For these reasons, the
techniques were only rarely employed.
Today’s use of solvents is quite modest in comparison with the older
methods.
3 b) CHEMICAL SOFTENING AND ADAPTATION
Chloroform dip technique
Usually on the tip of the point is dipped in the solvent and then only
for 1 second.
In this technique the primary point is blunted and fitted 2.0mm short
of the working length. It is then dipped in the solvent for 1 and set aside
while sealer is placed in the canal. This allows the solvent to partially
evaporate. Too much solvent, as with a two- or three- dip method, will
materially increase leakage. Not only does the gutta percha volume shrink as
the solvent evaporates in the canal, the sealer leaks as well, probably
because of solvent dissolution.
To begin the obturation by lateral compaction, one must immediately
position the customized master point to its full measured length and then
spread it aside to allow the softened gutta percha to flow. The spreader is
rotated out and is followed by additional points, spreader and points.
Because 2.0 mm of the master tip have been solvent softened, it will flow to
place to produce “smooth, homogeneous, well condensed gutta percha fills

closely adapted to the internal canal configurations in the apical third,
including the filling of lateral canals, fins and irregularities.
According to a study by Metzger et al (1988) the point should be
positioned and spread within 15 seconds of being softened, otherwise, it will
have lost its plasticity. After 30 seconds of air drying, it changes shape. This
simple chloroform dip shrank only 1.4%.
The principal solvent used in this technique is chloroform. At one
time there was concern that it was carcinogenic, but it has recently been
cleared for clinical sue in dentistry by the FDA, occupation safety and health
administration, and ADA. In any event, other solvents such as eucalyptol,
halothane, xylene, and rectified turpentine have been evaluated as substitutes
for chloroform. Customizing master points with solvents improves the seal
of gutta-percha.
From cohen
The apical 2 to 3 mm of a slightly oversized master cone is placed in a
solvent (eg chloroform, methylchloroform, rectified white turpentine,
eucalyptol) (Eucalyptus oil). For about 3 to 5 seconds, removed and placed
into the canal until the working length is achieved with a good apical fit. The
position of the cone in the canal is marked with regard to depth of placement
and orientation to curves. This can be done by scoring the cone with either a
cotton forceps or an explorer. The cone is fit into the canal when an irrigant
is present to prevent the adherence of the softened gutta percha to the canal
walls and to moderate the action of the solvent. Once fit the cone is checked
radiographically, removed and thoroughly irrigated with sterile water to
eliminate any residual solvent. Alcohol can also be used to remove the

solvent and the master cone should be allowed to dry for 1 or 2 minutes
before cementation and compaction.
Main disadvantages
1. Dramatic shrinkage of the solvent softened material.
2. High incidence of overfilling.
3. Potential toxicity of these materials.
4. The apical foramen is generally wider than the root canal orifice.
This would prevent proper condensation of the gutta percha, and proper
preparation of the canal would weaken the tooth considerably.
5. Difficulty of assessing the point of root development radiographically
because root formation in the buccolingual plane is less advanced than it is
in the mesiodistal plane. Completely obturation of these canals requires a
modification of the master gutta percha cone to better adapt to the irregularly
formed apical matrix or barrier. This may be accomplished by
1. Blunted points
2. Inverse point technique
3. Apical adaptation technique/direct impression technique
a. Heat softening of commercially available, large
cones.
b. Chemical softening of commercially available
large cones.
4. The creation of a large custom cone
- by heat
- by chemicals

The details of each technique are as follows
a. Heat softening and adaptation
- Heater water is used to soften the apical portion of the
master cone before it is placed in the canal. The cone is
dipped into the water (100o
to 120o
F, 37.8o
to 48.8o
C)
for 2 to 4. seconds to soften only the outer layers of the
apical portion of the cone.
- Flash heating over the flame
- End point of the primary gutta percha cone is
plasticized with a heated instrument.
The root canal is dried with sterile absorbent papers and a gutta percha
master cone is selected. The cone must have adequate ‘tug – back’ 0.5
mm short of the working length. The blade like end of a stainless steel
Woodson instrument is then heated for 6-7 seconds in a salt or glass
bead sterilizer (230 – 240o
C) and the hot instrument is used to transfer
the heat to the tip as well as the lateral surface of the apical 2-3mm of
the gutta percha master cone. The contact time of the heated
instrument on the gutta percha master cone is relatively quick (1-2
seconds). In cases where the size of gutta percha master cone is large
2-3 heating cycles may be needed to plasticize the tip of the cone
adequately.

Customized Master Cone Development (from Weine)
An imprint of the apical portion can be obtained by using a solvent,
and a master cone can be developed. The suggested solvent is chloroform,
preferred because it is more volatile than xylol or oil of eucalyptol, and no
solvent adhering to the cone is desired during condensation. Cotton pliers
with a lock or a hemostat are also mandatory in this technique because the
cone must be inserted into the canal several times in exactly the same spatial
relationship. By holding the cone with a locking device and using some
portion of the tooth usually a cusp tip or incisal edge as a landmark, the
dentist can reinsert the cone in the same path as frequently as necessary to
obtain a satisfactory imprint.
A master cone that has correct length and width is seized with pliers at
the predetermined length and dipped into a dappen dish containing
chloroform. Only the apical 5mm of the cone is dipped, for 1 to 2 seconds.
The softened cone is then placed into the prepared canal with slight apical
pressure, held for a few seconds, and withdrawn. This procedure should be
repeated at least one more time or until a satisfactory imprint is obtained. If
a correct preparation has been made, the cone will assume a pointed tip, and
striations will be noted along the lateral portion, recapitulating the canal
interior. It is advisable to have the canal filled with irrigant while the imprint
is taken. Either NaOCl or anaesthetic solution is very good for this purpose.
Otherwise, some of the softened gutta percha might stick to the dried dentin
walls and cause distortion of the cone.
When the cone has assumed what appears to be an accurate shape, a
radiograph is taken to verify the correctness of the apical position. During

the time that the radiograph is being developed, the cone should be removed
from the canal and retained in the locking pliers, so that it may be correctly
reinserted during filling. At this time, any residual solvent will volatilize and
the cone will regain its original rigidity.
If the cone is found to be too long, the dentist usually can easily tell at
which point it passes through the apical foramen. A constriction in the cone
is seen, with the area past this constriction being irregular and frequently
having residual blood. The error in working length is calculated and
corrected to the site of the constriction. The apical portion of the canal is
enlarged by one or two more sizes, and another customized cone obtained.
Once its correct length is verified the cone is used in one of the acceptable
cementing techniques.
Taking an imprint for a customized cone
a. Chloroform is poured into a dappen dish. A master cone with correct
length and width is grasped with the locking pliers at the working
length and dipped into the chloroform for a few seconds.
b. While being held with the cotton pliers, the cone (tip softened by the
chloroform) is inserted into the canal with slight apical pressure. The
canal has been irrigated with NaOcl for lubrication.
c. The cone assumes the shape of the interior of the canal with a pointed
tip and lateral striations.
d. If the cone passes through the apex into periapical tissue, residual
blood is seen near the tip. The true apical foramen is indicated by the
constriction prior to the indication of bleeding. To correct this
problem, measure the distance to the true apex, enlarge several sizes,
and then take a new custom cone.

2. Inverted point technique
The particular type of canal for which this method of filing is most
applicable is the tubular canal found in the tooth that suffered early depth of
the pulp, or one that has been ‘resurrected’ by apexification as cited above.
As a primary point, a “coarse” gutta percha cone is selected and the
serrated butt end of the point is carefully removed with a scalpel. The point
is inverted and tried in the canal, that is, it should visibly go to full depth,
but stop dead just short of the apex. It should exhibit “Tugback” when an
attempt is made to remove it. Finally it should appear in the radiograph to
be in optimum position to obliterate the foramen area of the canal.
If the inverted point is thought to fill correctly, the requirements of a
primary point, the canal is liberally coated with cement and the cement
coated is slowly pushed to full position. This point may act as a plunger
because of the shape of the canal and the tight fit of the point. If the point is
placed slowly, relatively little cement will be forced into the peri radicular
tissue.
When the primary inverted point is in place, additional gutta percha
points should be carefully added by lateral condensation with the spreader. It
is most important at this time to mark the length of the tooth on the spreader.
So the instrument will not penetrate into the peri radicular tissue. The
spreader is used repeatedly followed by auxiliary gutta percha points until
the canal is totally obliterated. The common error in this technique is an
outgrowth of fear of overfilling. Insufficient pressure is applied during
lateral condensations, resulting in poorly condensed filling. This in turn
allows subsequent leakage and uncrates failure.

Root canal obturation for large canal using inverted, blunted gutta
percha cone.
a. Inverted cone should adequately fill apical canal space. Spreader
should reach to within 1.0mm of foramen.
b. Total obturation with additional points. Excess gutta percha and
sealer are removed from crown filled by vertical compaction with
large plugger.
5. Special method of obturating tubular canals with closed apex
Simpson T and Natkin E. (1972)
Simpson and Nathin have suggested a specialized filling technique for
those teeth with tubular canals but closed apices. These are the roots that
were originally blunderbuss in shape, but have been induced to complete
their growth by the introduction into the root canal of a biologically active
chemical such as calcium hydroxide.
The canal is initially filled with a warmed and softened a tailor made
gutta percha roll cemented to place and several at the canal orifice with a hot
spoon excavator. Using a heavy plugger, the gutta percha is forced to apex
and compacted to place. Pressure with the plugger will leave a void in the
center of the mass when the plugger is removed with a twisting motion. It
may be necessary to hold the gutta percha in place with an explorer when
removing the plugger. The plugger is dipped in oxyphosphate of zinc
powder to prevent sticking and then used to collapse the gutta percha into
the space created by the initial plugging. If the gutta percha begins to set, the

plugger is heated to better compact the filling. With heavy vertical pressure,
the entire canal is obturated and the excess gutta percha seared off at the
gingival level.
a. Large cold plugger is used to force heat softened tailor made gutta –
percha to apex.
b. Twisting removal of plugger leaves a central void
c. Plugger is used to collapse gutta percha into void.
d. Heated plugger may be used to further compact filling.
e. Final obturation by adding sections of gutta percha with vertical
compression.

A. Cross section of tubular canal in “young” tooth, ovoid in shape.
B. Blunted, “coarse” gutta-percha cone or tailor made cone used
as primary point, followed by spreading and additional points
to totally obturate ovoid space. Final vertical compaction with
large plugger.

Root canal obturation for large canal using inverted blunted gutta-percha cone.
A. inverted cone should adequately fill apical canal space. Spreader should reach
to within 1.0 mm of foramen
B. total obturation with additional points. Excess gutta-percha and sealer are
removed from crown filled by vertical compaction with large plugger.

Special method of obturating tubular canals with closed apex.
By Simpson and Natkin
A. large cold plugger is used to force heat softened tailor made gutta percha to the apex
B. twisting removal of plugger leaves central void
C. plugger is used to collapse gutta percha into void
D. heated plugger may be used to further compact filling
E. final obturation with addition sections of gutta percha with vertical compaction

II. SHORT FILL TECHNIQUE
Moodnick proposed removal of the bulk of the necrotic tissue and
filling the root canal short of the apex with gutta percha. He advocated used
of Diaket (Premier Dental Products), a compound of beta ketones and zinc
oxide, in place of gutta percha to enhance healing. However with an
incomplete obturation microbes can be left remaining within the apical part
of the root canal system and healing may not take place or periapical
breakdown may occur later.

III. ENDODONTIC SURGERY ON IMMATURE TEETH
The idea of surgical manipulation and repair of an incisor tooth with
open apex is not a new concept, but one that has been around for quite some
time. Frank and Leubke during the 1960’s presented cases involving necrotic
incisors with immature apices and discussed their surgical intervention and
repair with amalgam. However, this treatment alternative never become
popular or accepted. Calcium hydroxide apexification became the standard
by which to treat these cases. Retrospectively, one reason for the dismissal
of such a practical one appointment treatment was poor patient selection.
But most importantly, amalgam that was used as an apical repair material in
these specific cases was, and is, inadequate.
(EARLIER) REASONS FOR NOT ADVOCATING SURGICAL
APPRAOCH
Article 36
I.C. Mackie, E.M. Bentley and H.V. Worthington.
1. Relative to the already shortened roots, further reduction during the
apicectomy could result in an inadequate crown to root ratio.
2. General anaesthesia is frequently required for the apicectomy in these
young patients and surgery could be both physically and
psychologically traumatic to the young patient.
3. The young patient is not apt to be cooperative.
4. Surgery would remove the root sheath and prevent the possibility of a
further root development.
5. The apical walls of an immature root canal are thin due to lack of
dentine apposition and could shatter when touched by a rotating bur.

6. The thin walls, are prone to fracture during the preparation of an
undercut for the apical amalgam seal
7. The thin walls would make condensation of a retrograde material like
amalgam difficult. This can result in an inadequate seal.
8. The peri apical tissue may not adapt to the wide and irregular surface
of the amalgam.
9. The delayed expansion of amalgam and its effects in the thin root
canal walls of these immature incisors.
10.The well recognized phenomenon of argyrophilic gingival tattooing
was a common unacceptable clinical sequela of amalgam apical repair
of teeth with immature apices.
Currently with the decline in use of amalgam as a retrograde material and
with the availability of newer retrograde filling materials, surgical treatment
of these teeth in a one step apexification model is being considered as a
possible alternative.
Indication
- Initially, when large chronic apical lesions are present
on an immature tooth at an evolutionary stage, which
no longer corresponds to the patients age.
- Secondly, after failure of apexification.

Advantages
- Rapidity of treatment by fewer appointments than in the
treatment by apexification.
- Reduction of the risk of fractures by reinforcing dentin
walls with dentin bonding materials like GIC.
- Immediate suppression of periapical lesions
- An efficient, reliable apical barrier, ensuring better and
easier 3 dimensional canal filling.
Possible causes of unsuccessful treatment.
- Hidden root failure
- Inefficient leakage resistance of the retrograde closure
resulting from inappropriate handling of GIC.
- Inefficient curing of the periapical lesion resulting in
the appearance of further lesion.
Not recommended
- For patients whose general health is poor.
- For children not inclined to cooperate.
- When there is insufficient bone substance for the tooth
needing treatment.

MATERIALS PROPOSED FOR USE IN ENDODONTIC SURGERY
1. Super ethoxy benzoic acid.
2. Mineral Trioxide Aggregate
3. Autopolymerizable glass ionomer cement.
CHARACTERISTICS OF RETRO-FILLING MATERIAL FOR
ENDODONTIC SURGERY
1. Autopolymerizable glass ionomer cement
- Chemical adherence to the dentine resulting in good
sealing ability.
- Efficient leakage resistance.
- Biocompatibility of the material with the apical tissues.
- Little tendency to dissolves in tissue fluids after setting.
- Ease of handling and of insertion because of its
condensable and auto polymerizable quantities
- Ease with which it can be polished resulting in a better
link with the peri apical tissues
- Radio-opacity.
- Good mechanical properties
- Low cost.
2. Super ethoxy Benzoic Acid (Super-EBA) cement
- The material is dimensionally stable and eliminates the
risk of root fracture by delayed expansion.
- Has high compressive and tensional strength

- Neutral pH.
- Low solubility
- Is biocompatible with the periapical tissues
- No tendency for tattooing the gingiva.
- (Some investigators suggest) sound adhesion to dentin)
- Improved leakage resistance with time.
- Exhibits minimal cyto toxicity
Disadvantages
- Hard to handle by the beginner
- Tacky and difficult to keep in place if not mixed to an
adequate consistency

Advantages of surgical alternative
i Cases are always complete
ii. Multiple appointments and long follow ups are not
necessary
iii. Inter appointment fracture are not a problem.
iv. Some of these immature apices are associated with large
apical lesions usually of necrotic pulpal etiology. But
surgical apexification permits the complete removal of the
lesion with its subsequent submission to an oral pathologists
for histological interpretation.
Limitations of surgical techniques
1. Should note be used in short rooted teeth with extreme apical
immaturity. The ostectomy and apical preparation, in these cases,
would compromise alveolar bone support and stability.
2. In young children who are dentally under developed and in whom
such a surgical procedure might lacerate an adjacent developing
tooth but, another vital immature root end, or hinder alveolar bone
development.
3. Medically compromised young adults or school children.
4. Patients who for one reason or another cannot be selected.

SEALERS TO BE USED
Ketac Endo (ESPE Ginbh, Seefeld, Germany)
- Glass ionomer cement endodontic sealer.
- Introduced by Ray HL, Seltzer S in 1991.
- Biocompatible in bone.
- Exhibits modified working and setting times
- No shrinkage upon setting.
- Superior adaptation to the canal walls.
- Radio opacity
- Dentinal bonding property makes root more resistant to
fracture.
- Earlier only a single GP cone was advocated when
using Ketac – Endo.
This also prevents vertical root treatment associated with gutta percha
condensation techniques.
- Highly resistant to resorption by tissue fluids
- Technically less demanding of effecting apical seals.
- Has an inherent, potential for providing for providing a
more stable apical seal.
- ZnO component of GP cones may chelate with the
polyacrylic acid and form salt bridges.
JOE, Vol.21, July No. 7, 1995 (Shimon Fried man)
In a clinical study using Ketac Endo concluded.
- Teeth with single canals showed a higher success rate
than teeth with multiple canals.

- Failure rate in teeth with infected canals and resulting
periapical lesions was almost 3 times higher than in
teeth without lesion.
- Treatment results significantly poorer in symptomatic
teeth.
- Treatment in single session resulted in a 10% higher
success rate than multiple session treatment.
- Teeth filled with a single cone or laterally condensed
GP comparable results.
- Extruded KE is not resorbed. It becomes an implant in
the peri apical tissues allowing bone growth in its
immediate proximity without a fibrous tissue interface.
It does not stimulate as osteoclastic response.
- The type of restoration and the presence /absence of a
post did not significantly affect the success rate (KE
may have sufficiently sealed the canal even after post
placement and reinforced the roots against treatment)
JOE : Vol 23 No. 4 April 1997 –
- Absence of chemical bonding to cones.
- GP surface altered – by etching effect
- More of a mechanical /physical phenomenon

IV. APEXIFICATION
Reasons for introduction of apexification
In the past, techniques for management of the open apex in non-vital teeth
were confined to custom fitting the filling material (16, 17), paste fills (18)
and apical surgery (19). A number of authors (16, 17) have described the use
of custom fitted gutta-percha cones, but this is not advisable as the apical
portion of the root is frequently wider than the coronal portion, making
proper condensation of the gutta-percha impossible. Sufficient widening of
the coronal segment to make its diameter greater than that of the apical
portion would significantly weaken the root and increase the risk of fracture.
The disadvantages of surgical intervention include the difficulty of obtaining
the necessary apical seal in the young pulpless tooth with its thin, fragile,
irregular walls at the root apex. These walls may shatter during preparation
of the retrocavity or condensation of the filling material. The wide foramen
results in a large volume of filling material and a compromised seal.
Apicoectomy further reduces the root length resulting in a very unfavorable
crown root ratio. The limited success enjoyed by these procedures resulted
in significant interest in the phenomenon of continued apical development or
establishment of an apical barrier, first proposed in the 1960s (20, 21).
DIFFERENT METHODS OF APEXIFICATION
1. Removal of infected necrotic pulp tissue
Moller et al. (23) have shown that infected necrotic pulp tissue induces
strong inflammatory reactions in the periapical tissues. Therefore removal of
the infected pulp tissue should create an environment conducive to apical

closure without use of a medication. McCormick et al. (24) have
hypothesized that debridement of the root canal and removal of the necrotic
pulp tissue and microorganisms along with a decrease in pulp space are the
critical factors in apexification. A number of authors (25-28)have described
apical closure without the use of a medicament. Some believe that
instrumentation may in fact hamper root development and that preparation
of these canals should be done cautiously, if at all (29). Cooke and
Robotham (30) hypothesize that the remnants of Hertwig's epithelial root
sheath, under favorable conditions, may organize the apical mesodermal
tissue into root components. They advise avoidance of trauma to the tissue
around the apex. This theory is supported by Vojinovic (31) and Dylewski
(32).
2. Use of antiseptic or antibiotic pastes
Much of the early work in the area of induced apical closure focused on the
use of antiseptic and antibiotic pastes. A number of investigators (33, 34)
demonstrated apical closure using an antiseptic paste as a temporary filling
material following root canal debridement and Ball (35) successfully
reproduced these results using an antibiotic paste. conditions for
conventional root canal filling. Rule and Winter used a polyantibiotic paste
to close the apex, and in some cases, described continued root development.
3. Induction of a blood clot in the peri radicular tissues

Many techniques have been suggested for induction of apical closure in
pulpless teeth to produce more favorable conventional root canal filling.
Most of these techniques involve removal of the necrotic tissue followed by
debridement of the canal and placement of a medicament.
However, it has not been conclusively demonstrated that a medicament is
necessary for induction of apical barrier formation. Nygaard-Ostby
hypothesized that laceration of the periapical tissues until bleeding occurred
might produce new vital vascularized tissue in the canal. He suggested that
this treatment 'may result in further development of the apex' (22).
Ham et al 1972 also reported closure of the end of the root, by ‘induced
blood clot’. The periapical tissues were deliberately probed with a file until
bleeding occurred. Closure was achieved, but not as often as with calcium
hydroxide. Article 36 I.C. Mackie, E.M. Bentley and H.V. Worthington.
It is accepted that in luxated or avulsed teeth with open apices,
revascularization is a possibility. In fact, under ideal conditions and with
chemical decontamination of the root surface, it is almost predictable. The
explanation for this positive outcome is that although the pulp is devitalized
after avulsion, it will stay free of bacteria for some time. The necrotic but
sterile pulp will act as a matrix into which new tissue can grow. Because in
traumatized teeth the crown is usually intact, it will take bacteria a long time
to advance into the pulp space. If in this time, the new vital tissue fills the
canal space, the ingress of bacteria will be stopped.
Regeneration of a necrotic pulp is considered possible only after avulsion of
an immature permanent tooth. The advantages of pulp revascularization lie

in the possibility of further root development and reinforcement of dentinal
walls by deposition of hard tissue, thus strengthing the root against fracture.
After reimplantation of an avulsed immature tooth, a unique set of
circumstances exists that allows regeneration to take place. The young tooth
has an open apex and is short. Which allows new tissue to grow into the
pulp space relatively quickly. The pulp is necrotic but usually not infected,
so it will act as a matrix into which the tissue can grow. It has been
experimentally shown that the apical part of a pulp may remain vital and,
after reimplantation, may proliferate coronally, replacing the necrotized
portion of the pulp. In addition, the fact that, in most cases, the crown of the
tooth is intact ensures that bacterial penetration into the pulp space through
cracks and defects will be a slow process. Thus, the race between the new
tissue and infection of the pulp space favors the new tissue.
However, if it were possible to create a similar environment in a
necrotic infected tooth with apical periodontitis as described for the avulsed
tooth, regeneration should occur. Thus, if the canal was effectively
disinfected, a matrix into which new tissue could grow was created, and the
coronal access was effectively sealed, regeneration should occur as in an
avulsed immature tooth.
Revascularization or regeneration of pulp tissue of necrotic immature tooth
has been assumed to be impossible because it is extremely difficult to
disinfect these canals. Mechanical instrumentation, an important step in root
canal treatment, cannot be performed in these teeth because the walls are so
thin. Thus, the disinfection relies solely on irrigants and intra canal
medications. Traditionally, calcium hydroxide has been used as the

intracanal medication in apexfication procedures destroying tissues with the
potential to differentiate into new pulp. Thus, with calcium hydroxide
therapy, there is no expectation that the root canal walls will be thickened or
strengthened. To the contrary, in a recent study, it was claimed that long
term calcium hydroxide treatment will in fact weaken the tooth and
predispose it to fracture
Article 17
Francisco Banchs and Martin Trope 2004
Francisco Banchs and Martin Trope 2004 in a case report describes the
treatment of an immature second lower right premolar with radiographic and
clinical signs of apical periodontitis with the presence of a sinus tract. The
canal was disinfected without mechanical instrumentation with the use of
copious irrigation followed by a mixture of antibiotics. A blood clot was
then produced to the level of the cementoenamel junction (CEJ), followed
by a deep coronal restoration. With clinical and radiographic evidence of
healing as early as 22 days, the large radiolucency had disappeared within 2
months, and at the 24months recall, it was obvious that the root walls were
thick and the development of the root apical to the restoration was similar to
that of the adjacent and contra lateral teeth.
However with respect to the origin of the new pulp tissue, the authors could
not be sure whether the vital tissue was pulp. However, based on the fact
that the root continued to grow and that the walls of the root appeared to
thicken in a conventional manner, it is likely that in the particular case, the
tissue was in fact pulp with functioning odontoblasts. It was possible that
some pulp tissue may have survived apically, even though most of the pulp
was devitalized and heavily infected. Therefore, even though a large apical

lesion was present, it is probable that some vital pulp tissue and Hertwig’s
epithelial root sheath remained. When the canal was disinfected and the
inflammatory conditions reversed, these tissues could proliferate.
Apexification of wide open apex due to resection
Article 35
C.M. Sedgley and R. Wagner 2003
This report describes a case where orthograde root canal treatment,
retreatment and root apex resection were unsuccessful in the treatment of an
infected mandibular right first molar. The periapical radiolucency eventually
disappeared following second orthograde retreatment, and the tooth
remained functional and asymptomatic 5years after aburation. Placement of
intra canal calcium hydroxide for 12 months promoted root end closure and
allowed obturation without extrusion of material into the periapical tissues.

NUMEROUS PROCEDURES AND MATERIALS HAVE BEEN
RECOMMENDED TO INDUCE APEXIFICATION IN TEETH WITH
IMMATURE APICES (LONG TERM APEXIFICATION
PROCEDURE).
v. No treatment
vi. Infection control
vii. Induction of a blood clot in the peri radicular tissues
viii. Antibiotics pastes.
Polantibiotic paste by Winter
ix. Calcium hydroxide mixed with various materials
x. BMP
xi. Collagen calcium gel.
Artificial apical barrier (that allows immediate obturation of the canal).
i. MTA
ii. Ca(OH)2 powder
iii. Super EBA
iv. Tricalcium phosphate

Although a variety of materials have been proposed for induction of apical
barrier formation, calcium hydroxide has gained the widest acceptance. The
use of calcium hydroxide was first introduced by Kaiser (20) in 1964 who
proposed that this material mixed with camphorated parachlorophenol
(CMCP) would induce the formation of a calcified barrier across the apex.
This procedure was popularized by Frank (21) who emphasized the
importance of reducing contamination within the root canal by
instrumentation and medication and decreasing the canal space temporarily
with a resorbable paste seal.
Calcium hydroxide is used because it biologically stimulates the hand tissue,
it is easy to prepare, any material beyond the apex is rapidly resorbed, it is
easy to prepare, any material beyond the apex is rapidly resorbed,it has a
high alkalinity.
Calcium hydroxide is a finely ground white powder that has little or no
solubility. It must be mixed with another substance to get it to the apical area
of the root in concentrations that remain constant and that do not weaken its
therapeutic properties. Generally the paste should contain as much calcium
hydroxide as possible whatever vehicle is used. The hydroscopic pastes
resorb more rapidly than do the oil base pastes.
Calcium hydroxide is not easily seen on the radiograph when well
condensed in the root canal, it may reach the radiopaque level of the dentin.
The addition of an element of a higher molecular weight than calcium will
permit better visualization of the paste. Iodoform, barium sulfate, or
strontium may be added.

TYPES OF Ca(OH)2 PRODUCTS USED FOR APEXIFICATION
- Prepared products
- Commercially available products
Prepared products
Alkaline pastes
These are primarily composed of calcium hydroxide in paste form mixed
with radio opaque substances and or medication
Alkaline pastes do not harden. They are quickly resorbed in the periapical
area and within the root canal. The speed of resorption iof indirect
proportion to the diameter of the root canal and in inverse proportion to the
density of the paste, its condensation, and the vehicle used. It may be used
alone or combination with cones of solid filling material. Actually this type
of filling materials is of a temporary nature, used only until apexification
has been achieved . The alkaline paste most frequently used are the
following.
Maisto capurro paste
Calcium hydroxide and iodoform in equal parts with distilled water or a 5%
solution of methylcellulose

Small cylinders of calcium hydroxide and iodoform implanted I the
subcutaneous tissue of the rat were resorbed at the same rate as those
containing only calcium hydroxide (Maisto and Masruffo 1964)
The calcium hydroxy is eliminated much more slowely than the iodofoorm
but this is not seen in the radiograph because it appears to be eliminate at the
same time as the iodoform.
These pastes are rapidly resorbed in the periapical region.the average time or
resorption is 1 to 10 days for each square millimeter of surface of over
obturated materials as seen in the radiograph
Frank’s Paste : Calcium hydroxide and camphorated parachlorophenol
The irritating properties of camphorated parachlorophenol hav ebeen dtudied
by many authors whoa re of the opinion that this material procedures a
severe inflammatory reaction on initial application.However Frank (1966)
Steiner et al (1968) Van Hassel (1970) and Stevart (1975) used this material
for the obturation of root canals of teeth with underdeveloped apices.
The fact that this paste was well tolerated by the adjacent periapical tissue
without any inflammation and with the deposition of osteodentin was
demonstrated histologically by Dyleskly in 1971 Souza,in his experimental
research in 1976,showed that the addition of camphorated parachlorophenol
did not change the capacity of the calcium hydroxide to induce the formation
of calcified tissue.It is possible that the camphored parachlorophenol is
absored and checking it irritating action.

Frank stated that camphorated parachlorophenol is an oily substance that
slows resoprtion of the paste and is an assurance that the paste will remain in
the areas of application for a longer time.
Calcium hydroxide and camphorated parachlorophenol (CMCP)
A number of studies (32, 36, 37) have reported a high level of clinical
success with the use of calcium hydroxide in combination with CMCP.
Leonardo’s paste
Calclium hydroxide barium sulfate, resin and polythyleneglyol
Leonardo called this paste, ”calcium hydroxide No.9” it is used
1. as a dressing between visits in cases of biopulpetomy
2. To protect the vital apical and pericapical tissues in the aobturation of
the root cananls.
3. As a temporary obturation inc ases of incomplete apexification to
induce mineralization and allow formation of new cementum.
Leonardo : calcium hydroxide 2 grams
Barium sulfate 1gram
Rosin 0.05gms
Polyethylene glycol 4000 1.75gms

Other combinations are
2. Calcium hydroxide and cresatin
Klein and Levy (38) and others (39, 40) described successful induction of an
apical barrier using calcium hydroxide and Cresatin (Premier Dental
Products). Cresatin had been shown to have minimal inflammatory potential
as a root canal medicament (41) and to be significantly less toxic than
CMCP (42).
3. Calcium hydroxide and saline/sterile water/distilled water
To further reduce the potential for cytotoxicity, the use of calcium hydroxide
mixed with saline (43), sterile water (44, 45) or distilled water (46) has been
investigated with similar clinical success.
Obtuartion with a hygroscopic paste has its disadvantages for it does not
slide easily along the entire length of the canal. On the contrary,the compact
consistency and the low mobility of the paste gives the feel that the root
canal has totally obturated when in reality the apical part of the canal is free
of paste. For this reason, it is preferable that the vehicle for the calcium
hydroxide be oily.
Commercially available products
1.Reogan Rapid
Reogan Rapid contains calcium hydroxide, barium sulfate, calcium oxide,
magnesium oxide, casein and distilled water

2.Pulpdent
Heithersay (47, 48) and others (49, 50) have used calcium hydroxide in
combination with methylcellulose (Pulpdent Corporation, Watertown, MA,
USA). Pulpdent has the advantage of decreased solubility in tissue fluids and
a firm physical consistency (51).
Pulpdent (consists of only calcium hydroxide, methyl cellulose and barium
sulfate
3.Calasept
Ghose et al., achieved a high success rate of 96% using Calasept to treat
teeth that had become non-vital following complicated crown fractures
4.Calcicur
5.Hypocal
Article 29 Mackie IC, Hill FJ, Worthington HV:
Because in 1989 it was found that Reogran Rapid was no longer going to be
marketed in the United Kingdom Mackie IC, Hill FJ, Worthington HV,
was decided to compare another readily available proprietary calcium
hydroxide paste, Hypocal, with the remaining stock of Reeogan Rapid.
Successful apical closure was achieved in all the teeth. However,the
differences in the mean time to achieve apical closure were not statistically
significant but they did show a trend in favour of shorter time and less visits
for apical closure in teeth treated with Hypo-cal.

Ca(OH)2 APEXIFICATION PROCEDURE
1. Measurement of apical opening
2. Access cavity preparation
I.C. Mackie, E.M. Bentley and H.V. Worthington recommends
preparing an access cavity that was large enough to permit
instrumentation of the walls of the wide pulp chamber and canal, but
did not weaken the crown of the tooth excessively
Article 36 I.C. Mackie, E.M. Bentley and H.V. Worthington.
3. Establish a working length
Because of the irregular shape of many incompletely formed teeth it may
not be possible to make the length determination with the same degree of
precision that is possible in fully formed teeth.
According to Robert J Oswald Henry j Van Hassel since the canal walls
in the apical region may be paper thin, there is probably some advantage to
establishing working length approximately 2mm coronal to the most apical
root edge. By working at this slightly coronal level, there is less likelihood
that the thin apical root structure will be torn by files. By restricting filing to
within the root canal there is also less likelihood that periapical tissue that
may still have the potential to participate in further root development will be
damaged, hence additional root structure may form apical to the level to
which calcium hydroxide was placed.
54. Robert J Oswald Henry j Van Hassel

4. Instrument the canal
Large sized files are recommended. Instrumentation in these instances could
be thought of as planing of all walls of the canal without an attempt to
increase the size of the canal. In particular it is difficult to adequately
debride the labial and lingual portions of the canal, since, as noted above, the
pulp chambers in the apical portion of these roots are frequently much wider
labio-lingually than they are in a mesio distal dimension.
According to Robert J Oswald Henry j Van Hassel in order to contact all
surfaces of the canal, it is necessary to place a curvature on the file.
3. Methods to control infection in the canal
According to Mackie IC, Hill FJ, Worthington HV if infection was
present, as indicated by pus in the root canal, this was controlled with a
polyantibiotic paste which was introduced using Lentulospiral root canal
filler to fill the canal. The access cavity was sealed using a cotton wool
pledget and zinc oxide eugenol cement. Where the infection was acute, the
first dressings was changed after 48 hours, subsequent polyantibiotic paste
dressings were replaced at weekly intervals until the infection was
controlled, a maximum of three being required before beginning treatment
with calcium hydroxide paste.

4. Methods to introduce Ca(OH)2 pastes in the canal
Webbers technique –using amalgam carrier and endodontic pluggers
Messing gun technique by Krell & Madison
Lentulospiral at very low speed
Mc Spadden compactor
Disposable syringe with a thick needle
Reamers turned counter clockwise
Leonardo’ssyringe
Article 36
The calcium hydroxide paste was introduced into the dry canal using the
needle dispenser provided. This allowed the paste to be injected well into the
root canal, with the needle being slowly withdrawn as the material was
injected. A spiral root canal filler was then used to ensure that the paste
filled the root canal to the full working length (ie 1 mm short of the
radiographic apex). More calcium hydroxide was injected into the canal if
necessary, and when the canal was completely full, a cotton wool pledget
was used to compress the paste gently before sealing the access cavity with a
zinc oxide/eugenol cement.

Plugging the Ca(OH)2 pastes in the canal can be done by moving the paste
into the apical canal with a long plugger that can be introduced to within 2 to
3 mm of working length without binding on any of the canal walls. Although
pluggers work well, some operators prefer to tamp the paste in place with
the butt ends of large sized paper points.
A large dry cotton pellet is then placed over the canal office, and additional
condensation with a large plugger is performed.
5. Timing of change of Ca(OH)2 dressing
Controversy exists as to whether or how often the calcium hydroxide
dressing should be changed.
Chawla (71) suggests that that it suffices to place the paste only once and
wait for radiographic evidence of barrier formation while Chosack et al. (72)
found that after the initial root filling with calcium hydroxide there was
nothing to be gained by repeated root filling either monthly or after
3 months. Proponents of a single application claim that the calcium
hydroxide is only required to initiate the healing reaction and therefore
repeated applications are not warranted.

The first calcium hydroxide dressing was replaced after one month.
Subsequent dressing were changed every 3 months until a calcific
barrier formed at the apex
A number of authors (73, 74) propose that the calcium hydroxide should be
replaced only when symptoms develop or the material appears to have
washed out of the canal when viewed radiographically.
Abbot (75) points out that radiographs cannot be relied upon to determine
the amount of calcium hydroxide remaining in the canal or to demonstrate
whether or not the barrier is complete. He concludes that regular
replacement of the dressing has a number of advantages. It allows clinical
assessment of barrier formation and may increase the speed of bridge
formation (). Abbot (75) suggests that the ideal time to replace a dressing
depends on the stage of treatment and the size of the foramen opening. This
must be assessed for each individual tooth at each stage of development.
As long as the patient remains asymptomatic the first scheduled recall
should be at approximately 6 months. At that time a radiograph is taken, in
addition to making a clinical evaluation of mobility palpation and percussion
tenderness and the status of the temporary filling. The radiograph should be
examined to determine
1. If any calcification has occurred in the apical region.
2. If paste can still be seen inn the root canal.
It root end closure is occurring but is not complete, the paste can be seen in
the canal, and the temporary filling is in act, the paste should not be
disturbed. In the event that you cannot see signs of apical closure, the paste

is not evident in the canal, or the temporary filling is breaking down, the
tooth should be reopened and the instrumentation procedures and calcium
hydroxide placement should be repeated.
Recall visits should be continued at 6 months intervals until there is good
radiographic evidence that the root end has closed
6. Procedures to detect barrier formation
In the methodology used by Ghose et al., immediately following the
placement of the calcium hydroxide paste, a radiograph was taken to ensure
that the paste completely filled the canal and, if voids were present, the
dressing was repeated. The patients were then recalled monthly and a
periapical radiograph taken to check for barrier formation and whether the
calcium hydroxide paste was being absorbed at the apex. Only when the
paste was not evident in the canal, or if it had been partially absorbed, was
the tooth redressed.
In these days when there is growing concern about the amount of radiation
to which children are exposed, the technique described by Mackie IC, Hill
FJ, Worthington HV keeps the number of radiographs taken to a minimum
by checking for the formation of a barrier at the apex clinically rather than
radiographically

A very precise procedure was used to detect barrier formation. First the
calcium hydroxide paste, which was non setting, was washed out of the
canal with a disposable syringe and needle. After drying the canal, a paper
point was then used to check the apical end of the canal when the presence
of a resistant “Stop” and the absence of haemorrhage, exudates or sensitivity
indicated successful barrier formation.
Article 36
The presence of a barrier was initially investigated by use of a thin paper
point. A calcific barrier was felt was a definite hard tissue stop at the root
apex. If a stop was located, a file was gently introduced to confirm that the
barrier completely occluded the root apex.
When you have radiographic evidence of root end closure, the tooth should
be isolated and reopened. The final test that the root end has in fact calcified
is made with #25 file. Since in some cases the bridge will be incomplete
regardless of the radiographic appearance. The files should be incomplete
regardless of the radiographic appearance. The files should be used to probe
the entire surface of the calcified bridge. If the clinical test demonstrate a
“dead stop” in all areas, obturation with gutta percha can be performed. If on
the other hand voids are found in the bridge, consideration should be given
to replacing the calcium hydroxide paste for another 6 months or until the
bridge is complete.

MECHANISM OF ACTION OF Ca(OH)2 TO INDUCE FORMATION
OF A SOLID APICAL BARRIER
The continuous absorption/depletion of Ca(OH)2 paste from the root
canal suggests that it is continuously used in the formation of the bridge. The
mechanism by which Ca(OH)2 acts in the formation of the bridge is still not
fully understood.
Number 2 Tarun Walia / Harpinder Singh Chawla And Krishan Gauba
However, Holland described in vivo, a phenomenon when calcium
carbonate crystals were produced by a reaction between the carbon di-oxide
in the pulp tissues and the calcium of the capping materials.
Alkaline pH and calcium ions might play a part either separately or
synergistically. The calcium required for the apical bridge formation comes
through the systemic route as demonstrated by Sciaky and Pisanty. Pisanty
and Sciaky using radiolabled Ca(OH)2.
As the calcium ions from the calcium hydroxide dressing do not come from
the calcium hydroxide but from the bloodstream (52, 53) the mechanism of
action of calcium hydroxide in induction of an apical barrier remains
controversial. Some of the postulated mechanisms of the osteoconductive
effects of Ca(OH)2 are as follows:
1. Presence of high calcium concentration increase the activity of
calcium dependent pyrophosphatase
Mitchell and Shankwalker (54) studied the osteogenic potential of calcium
hydroxide when implanted into the connective tissue of rats. They concluded

that calcium hydroxide had a unique potential to induce formation of
heterotopic bone in this situation. Of 11 other materials used in comparative
studies, only plaster of Paris (calcium sulfate hemihydrate) and magnesium
hydroxide demonstrated any osteogenic potential.
Heithersay (47, 48, 51) has postulated that calcium hydroxide may act by
increasing the calcium concentration at the precapillary sphincter, reducing
the plasma flow. In addition, the calcium ion can affect the enzyme
pyrophosphatase, which is involved in collagen synthesis. Stimulation of
this enzyme can facilitate repair mechanisms.
2. Direct effect on the apical and periapical soft tissue
Holland et al. (55) have demonstrated that the reaction of the periapical
tissues to calcium hydroxide is similar to that of pulp tissue. Calcium
hydroxide produces a multilayered necrosis with subjacent mineralization.
Schroder and Granath (56) have postulated that the layer of firm necrosis
generates a low-grade irritation of the underlying tissue sufficient to produce
a matrix that mineralizes. Calcium is attracted to the area and mineralization
of newly formed collagenous matrix is initiated from the calcified foci.
Schroder and Granath showed that OH ions induced the development of a
superficial necrotic layer acting as a surface to which the pulpal cells gets
attached, leading to bridge formation.

3. High pH, which may activate alkaline phosphatase activity
It appears that the high pH of calcium hydroxide is an important factor in its
ability to induce hard tissue formation. Javelet et al (57) compared the
ability of calcium hydroxide (pH 11.8) and calcium chloride (pH 4.4) to
induce formation of a hard tissue barrier in pulpless immature monkey teeth.
Periapical repair and apical barrier formation occurred more readily in the
presence of calcium hydroxide.
4. Antibacterial activity
It has been demonstrated that apical barrier formation is more successful in
the absence of microorganisms (58) and the antibacterial efficacy of calcium
hydroxide has been established). The antimicrobial activity is related to the
release of hydroxyl ions, which are highly oxidant and show extreme
reactivity. These ions cause damage to the bacterial cytoplasmic membrane,
protein denaturation and damage to bacterial DNA.

MECHANISM OF ACTION OF Ca(OH)2 BEYOND THE APEX IN
CASES WITH PERIAPICAL LESIONS
How the calcium hydroxide resorbs
Another aspect of calcium hydroxide that deserves comment is the
resorption of this material from within the root canal.
Several authors such as Sparagberg (1967) Tsushima(1970) Yamada (1970)
and Holland (19770 advise that the resorption of calcium hydroxide is in
keeping with the injury caused to the apical tissue by endodontic instruments
or by excessive filling.
Holand 91977) showed evidences in dogs teeth that,when pastes are grossly
overfilled,tehya re resorbed at different levels within the root cannal This
does not occur when the obturation is not overfilled.
According to strindberg (1956) the elimination of the filling paste is
facilitated by phagocytic action and or the dissolving of the filling material
by the tissue fluids.

Phagocytes takes place at pH6.9 and the pH of calcium hydroxide is
approximately 12.8The resorption would only be possible with the reduction
of the pH by the dissolving of the material in the tissue fluids.
Maisto and Erasquin (1965) were of the opinion that macrophages and
polymorphonuclear leukoctes can take part in the resorpton of material
within the root canal.
Souza believed that calcium hydroxide can be resorbed until the apex is
closed with calcified connective tissue, after the resorption will not be
possible.
55. Enrique Basrani

NATURE AND SOURCE OF CELLS PARTICIPATING IN
APEXIFICATION PROCESS
There has been considerable differences in opinion regarding the nature and
source of cells participating in apexification process
I. Mesenchymal or pluripotent precursor cells in the periapical region
(Hertwig’s epithelial root sheath )
Nevins A J et al 1978.
Herthersay G S 1970
Piekoff MD 1976
II. Cells of the dental sac which surround the apex (and retain their genetic
code) Klein and Levy 1974.
III. Hard tissue comes from 2 sources
1. Odontogenic activity of residual pulp cells. (Most prevalent and most
productive).
2. Connective tissue – cells maybe mesenchymal or fibroblastic in
origin (With the possibility that they have retained their
predetermined genetic pattern to form cementoblasts).
Torneck and Coworkers (1970, 1973)
IV. Pluripotent cells located within bone tissue (and that these cells are not
necessarily specific to the periapical region). Ohara PK, Torabinejad M
V. Hertwig’s epithelial root sheath

TYPES OF CANAL CLOSURE
1. 4 types by Frank (Frank A. L.)
2. Cathey’s apexification treatment 5th
type of canal closure
(Gerald M. Cathey)
The apical development continues with the growth of the tooth. According
to the studies done by Alfred Frank the types of maturation can be as
follows.
a. The apex keeps its blunderbuss form but is closed by a thin walled
calcific bridge.
b. The apex keeps its blunderbuss form and the bridge of calcified tissue
is formed beneath it.
c. Apical maturation is produced without the root canal changing its
form
d. The apex develops normally.
4 patterns of closure following apexification by Frank
1. Continued apical development with a definite though minimal,
recession of the root canal.
2. Continued apical development without any change in the root canal
space (dome apexification ) JOE : 1996. No.12.
3. Thin calcific bridge, formation at the apex without apical
development.
4. Lack of apical development with a calcific bridge just coronal to the
apex.
5th
type of canal closure (Cathey’s apexification treatment)

5. Continued apical development with calcific bridge just coronal to
apex.
(When the apical pulp can be retained in a vital condition, the root end
and canal usually with assume a relatively normal size and shape.
However when the pulp is completely non vital, root end develops in a
short plunted condition, where as canal remains rather wide when
apexification procedures are employed).

Article 33 Howard S. Selden (2002)
Although the radiographic shape of the apexification induced calcified
“Cap”, is variable. The most frequently seen closure seems to be a horizontal
bridge spanning the tips of the flared apex (type 3).
Howard S. Selden (2002) demonstrated in an interesting case the rare
occurrence of a type 1 closure pattern that morphologically resembled
normal root end formation in a lower left cuspid of a 12 year old male using
Ca(OH)2 paste which was changed only once every year for 2 years.
The unexpected formation of a mature apex served to demonstrate its
possibility, but not its predictability.
Successful treatment occurred with only two applications of Ca(OH)2
paste spaced 1 year apart, where as the widely accepted protocol
recommended changing the paste every 3 to 6 months.
The hard tissue barrier has been described by Ghose et al. (65) as a
Cap
bridge
ingrown wedge

NATURE OF INDUCED APICAL DEPOSITIONS
1. Cementum
2. Bone
3. Osteocementum
4. Osteodentin
5. Cementoid
Ghose et al. (65) described the hard tissue barrier as composed of cementum,
dentin, bone or 'osteodentin' (32). This osteodentin appears to be formed by
connective tissue at the apices, in that Hertwig's epithelial sheath is not seen.
Torneck et al. (66) reported that a bonelike material was deposited on the
inner walls of the canal while Steiner and Van Hassel (67) demonstrated
apical closure by formation of a calcific bridge that satisfied the usual
histological criteria for identification as cementum. Study of the serial
sections gave the impression that cementum formation proceeds from the
periphery of the original apex towards the center in decreasing concentric
circles. Scanning electron microscopy and histological analysis of the apical
barrier (70) demonstrated that the outer surface of the bridge extended in a
'cap like' fashion over the root apex, displaying irregular topography with
indentations and convexities throughout. The histological sections showed
distinct layers. The outer layer appeared to be composed of a dense acellular
cementum-like tissue. This surrounded a more central mix of irregular dense
fibrocollagenous connective tissue containing foreign material with irregular
fragments of highly mineralized calcifications.

CONSISTENCY OF NEW APICAL FORMATION
There are conflicting views regarding the structures of calcified bridge.
According to one school of thought, the bridge is a solid structure, consisting
predominantly of the cementoid tissue, while others are of the opinion that
bridge is porous with loose connective tissue inclusions in between.
In a clinical case by Tarun Walia / Harpinder Singh Chawla And
Krishan Gauba it was seen that following apical closure, the sealer (ZnOE)
used along with gutta percha for obturation had extruded beyond the bridge.
The author s concluded that if the calcified bridge would have been a solid
structure, the sealer could not have gone in the periapex. The bridge formed,
therefore is a porous structure.
Swiss cheese configuration (not solid)
In spite of radiographic and clinical evidence of complete apical bridge
formation, histological examination reveals that the barrier is porous (
55. Enrique Basrani
IN many cases, there is a slight overfill with the sealer which confirms the
histologic observation that the bridge of mineralized tissue is not complete.
But in some instances shows a sieve like appearance on microscopic slides.

MEAN TIME FOR APICAL BARRIER FORMATION
Studies vary in assessment of the time required for apical barrier formation
in apexification using calcium hydroxide.
In a review of ten studies, Sheehy and Roberts (79), reported an average
length of time for apical barrier formation ranging from 5 to 20 months.
Finucane and Kinirons (78) reviewed 44 non-vital immature incisors
undergoing calcium hydroxide apexification and found that the mean time to
barrier formation was 34.2 weeks (range 13-67 weeks).

FACTORS INFLUENCING TIME TAKEN FOR APICAL BARRIER
FORMATION AND HEALING.
1. Apical width
According to Finucane and Kinirons (78) a barrier formed more rapidly
in cases with narrower initial apical width.
Number 2
Tarun Walia / Harpinder Singh Chawla And Krishan Gauba Size of the
apical foramen at the start of treatment – Teeth with apices < 2 mm in
diameter have significantly shorter treatment times
Article 36
Root apices that were 2 mm in diameter or less took a geometric mean of 6.2
months to close. This was in contrast to those more than 2 mm in diameter,
which took 11.0 months to close, a significant increase. Since less calcific
material would be needed to occlude a narrow apex as opposed to a wide
apex, it would be expected that the former would require the shorter per for
treatment. This was confirmed by the results of this study, but contrasts with
those of Ghose et al., who failed to demonstrate a similar relationship.
2. Age
According to Finucane and Kinirons (78) age may be inversely related to the
time required for apical barrier formation. In one study patients who were

11 years or older had significantly shorter treatment times (76). Others,
however, refute this finding (80, 81).
Number 2
Tarun Walia / Harpinder Singh Chawla And Krishan Gauba
It was found that older children having narrow open apex had a shorter
treatment time than the younger children (NS); The calcified bridge formed
following apexification is a porous structure.
Age – May be inversely related to ABF time. Since less calcified material
would be needed to occlude a narrow apex as compared to wide apex, it
is understandable that the former would require shorter period for
apexification. In the study conducted by Mackie, patients, who were 11
years and older had significantly shorter treatment times. In the present
study also, the mean time required for ABF in younger age group (7 to 11
year) was 7.0 months, while for older age group (12 to 16 year), it was
5.0 months.
Article 36
I.C. Mackie, E.M. Bentley and H.V. Worthington. There was significant
differences in the time taken to achieve apical closure between the three age
groups ; 6-8 years, 9-10 years and 11-15 years. Significant differences were
also found between the times to achieve closure and the width of the apex.
There were no significant differences between closure times for the sex of
the patient, shape of the apex or the presence / absence of periapical
radiolucency.

3. Infection / periapical radiolucency
Cvek (73) has reported that infection and/or the presence of a periapical
radiolucency at the start of treatment increases the time required for barrier
formation but other studies indicate no relationship between pretreatment
infection and periapical radiolucency and barrier formation time (65, 76, 80,
81).
Number 2
teeth without periapical infection showed some amount of root growth and
closing of apex that was faster than those with periapical infection
(p<0.001).
Infection – Some studies have reported that presence of periapical radio
lucency at the start of treatment, increases the barrier formation time,
whereas others have not. In the present study, the former holders have
not. In the present study, the former holds true. In teeth without
periapical infection, the average time required for apical closure was 4.9
months, while whose with periapical radio lucency, the corresponding
figure was 8.5 months. The presence of periapical infection also
determines the number of dressings required for the apexification.
Article 36

. It was also interesting to note that the presence of a periapical radiolucency
did not affect the time taken for treatment. This is in agreement with Ghose
et al., but in contrast to Cvek and Sundstrom.
4. Inter-appointment painful symptoms
Kleier and Barr (80) found that in the presence of symptoms the time
required for apical closure was extended by approximately 5 months to
an average of 15.9 months.
Number 2
Inter-appointment painful symptoms – May delay time taken for apical
healing.
5. Frequency of Ca(OH)2 dressings
According to Finucane and Kinirons, the strongest predictor of rapid
barrier formation was the rate of change of calcium hydroxide
Number 2

Frequency of Ca(OH)2 dressings – there is no census on how frequently
Ca(OH)2 should be changed to induce apical healing. In the present study
calcium hydroxide paste was replaced, if it has resorbed in the apical one
third of the root canal until apical barrier formation is complete
6. Evidence of external resorption
7. Type of injuries
8. Method of detection of apical barrier
Article 29
Mackie IC, Hill FJ, Worthington HV:
The mean times to achieve apical closure of 6.8 and 5.1 months are
considerably less than those reported by Mackie et al of 10.3 months. The
reason for this is probably a change in the method used to detect the barrier.
Mackie et al used a fine file to check that the apical barrier completely
occluded the apical foramen and if any small deficiency was detected the
tooth was redressed for a further three month period. In this present study a
paper point rather than a file was used and this may not have detected small
deficiencies in the barrier. However, this change of method proved to be
acceptable since none of the final root fillings appeared radiographically to
have breached or broken the barrier

SUCCESS RATES
In a review of 10 studies, Sheehy and Roberts (79) reported that the use of
calcium hydroxide for apical barrier formation was successful in 74-100% of
cases irrespective of the proprietary brand used. They do point out that
follow-up is necessary and information regarding long-term outcomes is
limited. Problems such as reinfection and cervical root fracture may occur.
Number 2
A retrospective study on 15 non-vital immature incisor teeth was done using
Ca(OH)2 Pulpdent paste. A success rate of 100 percent was achieved within
one year.
The formation of apical barrier in all the fifteen teeth proves the
effectiveness of Pulpdent paste in apexification procedures. Majority of the
studies has reported high success rate using different Ca(OH)2 pastes for
apexification. Heithersay used Ca(OH)2 and methylcellulose in 21 teeth and
achieved apical closure in 90 percent of the teeth in the time range of 14 to
75 months.
Chawla treated 26 non-vital teeth using Reogen Rapid paste and the
success rate was 100 percent with 35 percent teeth showing apical closure in
twelve months and 65 percent teeth in six months
Thater used Pulpdent paste in 34 teeth, but achieved a lower success
rate of 74 percent as compared to 100 percent in our study. However, Kleier

achieved 100 per cent success rate as achieved in the present study using
Pulpdent paste on 48 teeth within 1 to 30 months.
Mackie used both Reogen Rapid and Hypocal on 19 teeth each for
apical closure and achieved 100 percent success using both the brands with
the mean time period of 6, 8 months for Reogen Rapid and 5.1 months for
Hypocal respectively.
Article 36
Successful closure of the apex of the root was achieved in 108 of the 112
incisors, representing a 96% success rate. three of the four failures occurred
in replanted teeth, while the other was displaced from its socket.

FACTORS INFLUENCING SUCCESS RATES
1. Type of trauma
2. Age
3. Presence of horizontal / vertical root fracture

INHERENT DISADVANTAGES OF CONVENTIONAL Ca(OH)2
APEXIFICATION
1. Patient Compliance
More apexification cases are started than completed. Patients or
parents lose interest in such a length to complete, multiple appointment
procedure.
2. Fracture before completion of treatment
Although crown and root fractures are an unpredictable happening,
they do occur occasionally in these immature wide canal incisors with in
root walls.
3. Referring dentists
referring dentists generally do not like the idea of waiting for nearly 1
year to have the case back in their practice.
4. Inconvenience of multiple appointments in the young adult scenario
In these cases, a discolored tooth is commonly the motivator. It is
usually after initial diagnosis by their dentist that patients know about their
apical immaturity and its relationship to the discoloration. However the
multiple appointments entailed by the apexification procedure. Obscures the
real chief complaint of this young adult group, which is improving esthetics
quickly.

5. Precise prognostic assessment sometimes impossible
An incisor with a hidden root fracture could be unwisely and
wastefully treated by apexification before the true nature of the problem is
noticed. This is an ever present possibility in immature teeth usually
devitalized by trauma.
6. Patient management
Behavioral problems in young patients are difficult to manage and
sometimes exacerbated by multiple appointments.
7. Economics
After tallying the cost for multiple appointments, plus the time taken
off from the work in the case of an adult, it is evident that apexification is an
expensive, time consuming proposition.
INHERENT DISADVANTAGES OF Ca(OH)2 apexification
1. Variability of treatment time.
2. Unpredictability of apical closure
3. Difficulty to patient follow up.
4. Delayed treatment.

MINERAL TRIOXIDE AGGREGATE
Although calcium hydroxide has been the material of choice for
apexification, a number of authors have worked with other materials. In the
1970s interest was expressed in the use of tricalcium phosphate for induction
of apical barrier formation with some success (82, 83). Nevins et al. (84)
reported favorable outcomes using collagen-calcium phosphate gel. In recent
times interest has centered on the use of mineral trioxide aggregate (MTA)
for apexification. This material was first introduced in 1993 and received
Food and Drug Administration (FDA) approval in 1998. MTA is a powder
consisting of fine hydrophilic particles of tricalcium silicate, tricalcium
oxide and silicate oxide. It has low solubility and a radiopacity that is
slightly greater than that of dentin (85). This material has demonstrated good
sealability and biocompatibility (86, 87). MTA has a pH of 12.5 after setting
which is similar to the pH of calcium hydroxide and it has been suggested
that this may impart some antimicrobial properties (88). It has been used in
both surgical and non-surgical applications including root end fillings (86,
87, 89), direct pulp caps (90), perforation repairs in roots (91) or furcations
(92, 93) and apexification (94, 95). Shababhang et al. (94) compared the
efficacy of osteogenic protein-1 and MTA with that of calcium hydroxide in
the formation of hard tissue in immature roots of dogs. They concluded that
MTA produced apical hard tissue formation with significantly greater
consistency. The difference in the amount of hard tissue formed among the
three test materials was not statistically significant.

BONE MORPHOGENIC PROTEINS
Used to promote bone formation
Osteogenic protein – 1 (OP-1)
Uses
- To induce bone formation
- Use as pulp capping agent.
- Root end induction.
- is believed to attract and recruit mononuclear
phagocytes to ectopic sites of bone formation.
- Stimulates proliferation of mesenchymal cells that
subsequently differentiate into osteogenic lineages.
- Purified BMP is highly soluble in vivo and hence for
hard tissue formation, is used with carrier – mostly
collagen carrier (collagen matrix carrier resorbs slowly
over a 3 week period when implanted in bone that
allows gradual release of the BMP) (Rate of resorption
may be slower when placed within confines of the root
canal).
- OP-1 induced an apical hard tissue formation with the
same frequency as seen in calcium hydroxide, however
in larger quantities (Similar to MTA)

While the objective of apexification is to stimulate apical barrier formation,
in the belief that continued root formation cannot occur, there are a number
of reports of continued apical development in spite of a necrotic pulp (109,
110). Yang et al. (111) reported a case in which apical barrier formation was
accompanied by a separate disto-apically growing root. Histological
evaluation revealed immature hard tissue mixed with calcium hydroxide,
connective tissue and bone apically in the original root canal. In the separate
newly formed part of the root, pulp tissue, odontoblasts, predentin,
cementum and an apical foramen could be identified. Selden (112) also
described a case in which the outcome morphologically closely resembled
normal root formation. It has been suggested that for continued root
development to occur the area of calcific scarring must not extend to
Hertwig's root sheath or to the odontoblasts in the apical area (113).

V. ONE VISIT APEXIFICATION
Induction of apical healing, regardless of the material used, takes at least 3-
4 months and requires multiple appointments. Patient compliance with this
regimen may be poor and many fail to return for scheduled visits. The
temporary seal may fail resulting in reinfection and prolongation or failure
of treatment. The importance of the coronal seal in preventing endodontic
failure is well established (). For these reasons one-visit apexification has
been suggested. Morse et al. (99) define one-visit apexification as the non-
surgical condensation of a biocompatible material into the apical end of the
root canal. The rationale is to establish an apical stop that would enable the
root canal to be filled immediately. There is no attempt at root end closure.
Rather an artificial apical stop is created. A number of materials have been
proposed for this purpose including tricalcium phosphate (100, 101),
calcium hydroxide (100, 102), freeze dried bone (103) and freeze-dried
dentin (104). Favorable results have been reported. Recently there have been
a number of reports describing the use of MTA in one-visit apexification.
Witherspoon and Ham (105) describe a technique using MTA. They assert
that MTA provides scaffolding for the formation of hard tissue and the
potential of a better biological seal. They conclude that this technique is a
viable option for treating immature teeth with necrotic pulps and should be
considered as an effective alternative to calcium hydroxide apexification.
Steinig, Regan and Gutmann (106) consider that the importance of this
technique lies in the expedient cleaning and shaping of the root canal
system, followed by its apical seal with a material that favors regeneration.
Furthermore the potential for fractures of immature teeth with thin roots is

reduced, as a bonded core can be placed immediately within the root canal.
A number of authors (95, 107, 108) have reported clinical success using
MTA for one visit apexification.

Tooth restoration following apexification
Although treatment of the immature apex is manageable, the thin dentinal
walls, particularly in the cervical area, present a clinical problem. Should a
second injury occur, teeth with thin dentinal walls are more susceptible to
fractures that can render them nonrestorable. It has been reported that ~ 30%
of these teeth will fracture during or after endodontic treatment.
Consequently, some clinicians have questioned the advisability of the
apexification procedure and have opted for more radical treatment
procedures, including extraction, followed by expensive restorative
procedures such as dental implants and a fixed partial denture.
Because of the thin dentinal walls there is a high incidence of root fractures
in teeth after apexification. Restorative efforts should be directed towards
strengthening the immature root. A number of studies have demonstrated
that the use of the newer dentin bonding techniques can significantly
increase the resistance to fracture of these teeth to levels close to that of
intact teeth (114). Goldberg et al. (115) have recently demonstrated the
reinforcing effect of a resin glass ionomer in the restoration of immature
roots. The risk of root fracture during apexification is a concern, but during
this time it is essential that access to the apical portion of the canal is
preserved. Katebzadeh et al. (116) have described a technique in which the
access is restored with a composite restoration. A clear curing post is
inserted into the soft composite and cured. The post is then removed leaving
a patent channel for calcium hydroxide replacement and subsequent
obturation of the canal.

Article 12
Nooshin Katebzadeh, B. Clark Dalton and Martin Trope 1998
Recent studies have shown that intracoronal acid-etched bonded resins can
internally strengthen endodontically treated teeth and increase their
resistance to fracture. In fact, the newer dentin bonding systems can
strengthen endodontically treated teeth to levels close to that of intact teeth.
This technique has been suggested as a restorative method to strengthen
teeth against fracture subsequent to apexification. Because the apexification
procedure takes up to 18 months to complete, these fractures may occur
during active treatment, before obturation of the canal. Rabie et al suggested
a modified acid etch technique to strengthen the tooth during the
apexification procedure. No data currently exist supporting the clinical
advantage of this strengthening technique.

MANAGEMENT OF OTHER PROBLEMS ASSOCIATED WITH THE
IMMATURE APEX
Thin dentinal walls
Without fracture
- intraradicular rehabilitation
glass ionomer cement
composite
With fracture
- non surgical management
calcium hydroxide
intraradicular rehabilitation
mineral trioxide aggregate
- surgical management
glass ionomer cement
mineral trioxide aggregate
- Extraction in untreatable cases
Frequent periapical lesions
- Non surgical treatment
calcium hydroxide
intracanal medicaments
- Surgical treatment

Fractures of crown
- Full crowns with / without post and cores
Discoloration in long standing cases
- Post endodontic bleaching
- Full crowns with / without post and cores

Conclusions
Every effort should be made to attain the genetically programmed closure of
the foramen that remains open because of early pulp death. This can be
accomplished by apexification a method of recharging the growth potential
and restoring root growth and foramen closure
Calcium hydroxide apexification remains the most widely used technique
for treatment of necrotic teeth with immature apices. Success rates are high.
However techniques for one-visit apexification provide an alternative
treatment option in these cases. Prospective clinical trials comparing these
alternative techniques are required.
Thus as can be seen from above, successful obturation of an incompletely
developed non vital tooth forms only one part of the treatment for such teeth.
Complete rehabilitation of these teeth requires that all the other associated
problems be taken into consideration while formulating a treatment plan.

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