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1. D. All of the above
2. B. Chronic pulpitis
3. C. Lateral spread of caries along DE junction and
weakening of the overlying enamel.The caries forms a small area of penetration in the enamel at
the bottom of a pit or fissure and does not spread laterally to a
great extent until the DEJ is reached. Force of mastication
fracture the increasing amount of unsupported enamel as thecaries progress so choice (4) is wrong. Destructive potential is
due to acid formed by bacteria by degradation of carbohydrates
so choice (1 & 2) also wrong.
4. B. Vaseline is an ideal choice.A water-soluble lubricant applied in the area of punched holes
facilitates the proximal contacts. Rubber dam lubricant is
commercially available but other lubricants, even as Having
cream or soap slurry also satisfactory. Cocoa butter and
petroleum jelly, these two are not satisfactory rubber dam
lubricants because both are Oil based and not easily rinsed from
dam once the dam is placed.
5. C. Reversibly denatured collagen.Affected dentin is softened, demineralized dentin that is not yet
invaded by Bacterua (Zone 2 & 3) Infected dentin (Zone 4 &
5) is both softened contaminated with bacteria.
It includes the superficial, granular necrotic tissue and softened,
dry, lathery dentin. The outer layer (infected dentin) can be
selectively stained by caries detection solutions such as 1%
acid red 52 (acid rhodamine B or food red 106) in propylene
glycol. This solution stains the irreversibly denatured collagen
in the outer carious layer but not the reversibly denatured
collagen in the inner carious layer.
6. A. Maxillary first premolarApproximately 60% have two roots, one buccal and the other
palatal, each with a single canal. The two roots may becompletely separate or merely twin projections rising from the
middle third of the root to the apex (this is more common). The
two roots are usually equal in length from apex to cusp.
However, the lingual root and canal may be wider. In
approximately 40% of maxillary first premolars, only one root
is present, usually with two separate canals. A cross section at
the cervical line shows a canal shaped like a figure eight
(ellipse). The access opening is a thin oval. Be careful not to
perforate on the mesial (the concavity on the mesial makes
perforation very common). Maxillary second premolars: The
most common configuration in this tooth is a single root,
occurring approximately 85% of the time. Approximately 15%
of the time, two separate roots are present, each with a single
canal. The access opening is exactly the same as that for
maxillary first premolars (thin oval). When only one canal is
present (first or second premolar), it is usually found in the
center of the access preparation. If only one canal is found, but
it is not in the center of the tooth, it is probable that another
canal is present Overfilling either tooth may force materials
directly into the maxillary sinus.
7. C. MesiobuccalCanal orifices of a maxillary first molar are arranged in the
shape of a triangle. The orifice to the mesiobuccal canal is
usually the most difficult to locate, since It is under the
mesiobuccal cusp and must be entered from a dlstollngual
position. This canal is the small canal and often splits into two
canals. It maybe calcified and difficult to instrument. The
palatal canal is the straightest, widest, and most tapering canal.
The most common curvature of the palatal root is to the facial.
The distobuccal canal is also small and tapering. The orifice to
this canal has no direct relation to its cusp. The distobuccal
orifice is usually located by means of its relation to the
mesiobuccal orifice, with the distobuccal found approximately
2 to 3 mm to the distal and slightly to the palatal aspect of the
mesiobuccal orifice. In approximately 59% of maxillary firstmolar teeth, a fourth canal Is present with its orifice being just
lingual to orifice to the mesiobuccal canal. The canal is located
in the mesiobuccal root and may join the mesiobuccal canal or
exit through a separate foramen. If a lesion is present on the
mesiobuccal root prior to root canal therapy and doesn't heal in
the usual amount of time (6-12 months) following treatment, it
is most likely due to a missed canal (mesio-lingual). The U-
shaped radlopaclty commonly seen overlying the apex of the
palatal root of the maxillary first molar is most likely the
zygomatic process of the maxilla.
8. A .Maxillary central incisor
9. B. Have film thickness of 1-50 microns.Liners are relatively thin layers of material used primarily to
provide a barrier to protect the dentin from residual reactants
diffusing out of a Restoration or oral fluid.
Thin film liners (1-50 micron)
Divided into
Solution liners Suspension liners
(Varnish 2-5 micron) (20-25 micron)
Thicker liners are used for pulpal medication and thermal
protection. For moderate depth tooth preparation liners are used
for thermal protection and pulpal medication. In very deep
preparation calcium hydroxide liner are used under gloss
ionomer restoration.
10. B. Thin meslodistally but wide lablolinguallyMandibular canines usually have only one root but in rare cases
may have two separate roots. The access opening is a large oval
with the greatest width placed incisogingivally. This tooth
usually has a slightly labial axial inclination of the crown
therefore the access opening needs to be directed towards the
lingual surface.
11. C. It does not alter dentin permeability.Reduction in sensitivity may result from formation of Resin
tags and a hybrid layer when a dentin adhesive is used. The
precipitation of proteins from the dentinal fluid in the tubulesalso may account for the efficacy of desensitizing solutions. So
after excluding the three option we can have answer.
12. D. Globulomaxillary cystAn apical scar is represented by a periapical granuloma, cyst, or
abscess that heals with scar tissue. Well- circumscribed
radiolucency resembling a granuloma. Tooth is non-vital. A
radicular cyst usually occurs in a pre-existing granuloma.
Seldom is painful. Radiolucency at apex of non-vital tooth. A
chronic dental abscess is often a result of a periapical
granuloma. Radiolucent area at apex of non-vital tooth. Fistula
is often found leading from an abscess cavity. Once drainage is
established, the tooth stops being painful.
A globulomaxillary cyst is found at the junction of the globulus
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and maxillary processes of the maxilla, between the lateral
incisor and the canine roots. It is a developmental (hssural)
cyst which arises from cells in a fissural line of bone. Teeth are
vital.
13. B. Easy to manipulateShort setting time MTA is difficult to manipulate and has a
long setting time. Despite these disadvantages, it's the material
of choice today. A retrofllllng (also called a reverse filling or
retrograde amalgam filling) is placed to seal the apical portion
of the root canal. This procedure is used when an apicoectomy
alone will not yield a good result Whenever there is any chance
whatsoever that an apical seal may be faulty, a reverse filling
material must be placed. For example, if the root canal appears
calcified, it would be impossible to obturate most of the canal
and get a seal. If just the root apex were cut off (apicoectomy),
the incompletely filled canal might act as a source of
reinfection. To prevent this after the root tip is resected, the
foramen is found, enlarged, and filled with a zinc-free amalgam
to create a seal. An apicoectomy (root resection, root
amputation) is a procedure where the buccal tissue is flapped
back, the buccal bone about the apex is removed, the root apex
is removed, and the area is curetted out. Indications forapicoectomy:
1. A reverse filling needs to be placed.
2. It is necessary to gain access to an area of pathosis.
3. The poorly filled apical portion of the root is to be removed
to the level of canal obliteration.
A retrograde amalgam filling should always be done after an
apicoectomy. Teeth that have posts in them and need to be
retreated are the most common reason for an apicoectomy and a
retrograde filling. Remember Periapical curettage is the same
procedure as an apicoectomy (as far as flap and removal of
buccal bone) but without removing the root apex. Removal and
examination of the diseased tissue and determination of the
extent of the lesion are the objectives of apical curettage.
14. B. Sensitivity to hot, and or, cold stimuliThermal sensitivity is the earliest and most common symptom
of an inflamed pulp. As caries enters the dentin it begins with a
lateral spread at the DEJ. This is due to the increased organic
content and the involvement of many dentinal tubules. The
Tomes fibers react, causing fatty degeneration, then later
decalcification (sclerosis). As caries progresses, destruction of
dentin is followed by the bacterial invasion of the tubules and
complete destruction of dentin. Once odontoblasts are
Involved, pulpal changes occur. Initially there is vascular
dilation and local edema. The earliest common symptom of this
edema (acute pulpitis) is thermal sensitivity (usually increased
and persistent pain on application of cold). The only reliableclinical evidence that secondary dentin has formed is decreased
tooth sensitivity (usually seen a few weeks after placement of a
filling). When dentinal tubules become completely calcified,
the dentin is insensitive.
The best method to elicit a most accurate thermal response is to
individually isolate the suspected teeth with a rubber dam and
then bathe each tooth in hot or cold water. This is done because
all other methods may stimulate the tooth at only one section of
one surface. Thermal tests may be false-negative in immature,
recently traumatized teeth or because of premedication with an
analgesic.
15. B. Nickel-Cobalt-Chromium is never used in its
fabrication.
Hand cutting instruments are manufactured from two main
material carbon steel & stainless steel In addition, some are
made with carbide inserts to provide more durable Cutting
edges. Carbon steel is harder than stainless steel, but when
unprotected, it will Corrode. Other alloys of Nickel, Cobalt &
Chromium are used in the manufacture of hand instruments but
they are usually restricted to instruments other than those used
for cutting of tooth structure.
16. B. AsymptomaticThe chronic apical abscess (also called suppurative apical
periodontitis) is sometimes so painless that it may go
undetected for years until revealed by an x-ray. It is a long-
standing, low-grade infection of the periapical bone with the
root canal being the source of the infection. This condition may
follow an acute alveolar abscess or unsatisfactory root canal
therapy. Radiographs will reveal a diffuse radiolucency and
PDL thickening. The tooth may be slightly loose or tender to
percussion. The chronic abscess may be differentiated from
cysts and granulomas by the fact that both cysts and
granulomas have well-defined radiolucencies associated with
them. The treatment is conventional root canal treatment. 30%
to 50% of bone calcium must be altered before radiographicevidence of periapical breakdown occurs (this alteration takes
place at the junction between the cortical and cancellous bone).
The acute apical abscess (AAA) is a localized collection of pus
in the alveolar bone at the root apex following death of the pulp
with extension of the infection into the periapical tissue. The
first symptom may be a slight tenderness of the tooth. This later
develops into a severe throbbing pain to percussion with
swelling of the overlying mucosa. The tooth becomes more
painful, elongated and loose. At times the pain may decrease or
disappear completely. The patient may appear weakened,
irritable and present with a fever. The diagnosis is based on the
history, exam, and radiographs. The tooth will not respond to
the EPT or cold test but may respond to heat Treatment of anacute alveolar abscess Includes establishing drainage and
debrldlng the canal system of necrotic tissue which will relieve
the acute symptoms. This Is followed at a later date by
conventional root canal therapy. If the abscess ruptures
through the periosteum into the soft tissue, the patient's
symptoms will subside.
17. C. Dental InfectionIt is not a particularly common disease. It is a serious sequela
of periapical infection that often results in a diffuse spread of
infection throughout the medullary spaces, with subsequent
necrosis of a variable amount of bone. Acute or subacute
osteomyelitis may involved either the maxilla or the mandible.
In the maxilla, the disease usually remains fairly well-localizedto the area of initial infection. In the mandible, bone
involvement tends to be more diffuse and widespread.
Clinically, the person afflicted with acute osteomyelitis is
usually in rather severe pain and manifests an elevation of
temperature with regional lymphadenopathy. The teeth in the
area of involvement are loose and sore so that eating is
difficult, if not impossible. Radiographically, acute
osteomyelitis progresses rapidly and demonstrates little
radiographic evidence of its presence until the disease has
developed for at least one to two weeks. At that time, diffuse
lytic changes in the bone begin to appear. A "moth-eaten"
radiolucent appearance is evident.
The general principles of treatment demand that drainage be
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established and maintained and that the infection be treated
with antibiotics to prevent further spread and complications.
18. C. Periapical abscessOf all the dental abscesses, the periapical is the most common
type. It is a localized collection of pus in the alveolar bone at
the root apex following death of the pulp with extension of the
infection into the periapical tissue. The first symptom may be a
slight tenderness of the tooth. This later develops into a severe
throbbing pain (acute abscess) with swelling of the overlying
mucosa. The tooth will not respond to the EPT or cold tests but
may respond to heat. Emergency treatment includes
establishing drainage (ideally through the canal) and
prescribing antibiotics and analgesics. This will relieve the
acute symptoms followed by conventional endodontic therapy
at a later date. For endodontic infections that do not respond to
penicillin, clindamycin is often recommended. It produces high
bone levels and is effective against anaerobic bacteria but must
be used with caution because of the potential for
pseudomembranous colitis. The periodontal abscess is an acute
abscess that develops through the periodontal pocket. Alveolar
bone loss, pocket formation and periodontal pathologic
conditions are suggestive of the periodontal abscess. The toothwill usually be palpation and percussion positive. It will
respond to the electric pulp tester (unlike the pehapical
abscess). Bacteria associated with this abscess include gram-
negative rods such as Capnocytophaga species, Vibrio-
corroding organisms and Fusobacterium species. The gingival
abscess is a relative rarity mat occurs when the bacteria invade
through some break in the gingival surface. Such abrasions may
be the result of mastication, oral hygiene procedures, or dental
treatment.
19. B. Irreversible pulpitisThe severity of the clinical symptoms will vary as the
inflammatory response increases. Pain will vary from a mild
and readily tolerated discomfort to a severe, throbbing andexcruciating pain. The pain is spontaneous and is intermittent in
nature. The pain lingers after the removal of the irritant. The
pain is usually not readily localized by the patient but is diffuse
in character. Lying down or bending over intensifies the pain of
irreversible pulpitis because the overall increase in cephalic
blood pressure is relayed to the confined pulp tissue. The tooth
may be tender to percussion, heat may intensify the pain
response while cold may relieve it (in advanced stages).
Usually they both will cause severe and lasting pain. The
radiographs will usually disclose no periapical pathology.
Treatment is root canal therapy.
Reversible pulpitis (hyperemia) -» the pain associated with
hyperemia does not occur spontaneously. It requires an externalirritant to evoke a painful response (i.e., cold, sweets). The
pains are sharp and of brief duration, ceasing when the irritant
is removed. Radiographs appear normal (may show deep caries
or cavity preparation). The tooth is usually percussion negative.
In thermal tests, the pulp responds more readily to cold stimuli
than to hot (the response leaves shortly after removal of the
stimulus). Treatment usually Is a sedative filling or new
restoration with a base. Pulpal Inflammation (hyperemia) is
most commonly caused by bacteria.
20. D. None of the aboveApexification Is a technique whose goal is to induce further
root development in a pulpless tooth by stimulating the
formation of a hard substance at the apex, so as to allow
obturation of the root canal space. Apexification may be
required after pulpectomy as at seven years of age the apex of
this tooth must be open. Remember: Apex closes 2-3 years
after eruption. The technique consists of isolation of the field
with a rubber dam, making an access cavity and removing all
pulpal tissue by the use of reamers and files. A premixed
syringe of a calcium hydroxlde-methylcellulose paste (for
example, a Pulpdent syringe) is injected into the canal until it is
filled to the cervical level. The paste must reach the apicalportion of the canal to stimulate the tissues to form a calcific
barrier. A double seal of cement is made to close off the access
cavity. The patient is recalled after three months to see if
apexification has taken place. If not, a fresh supply of paste is
placed. If apexification has occurred, conventional root canal
therapy is instituted. The action of calcium hydroxide in
promoting formation of a hard substance at the apex is best
explained by the fact that calcium hydroxide creates an alkaline
environment that promotes hard tissue deposition. If a
permanent tooth fractures and has a fully formed root and the
pulp is exposed (large exposure), the treatment of choice is
complete root canal therapy. Apexification is not needed
because the root is fully formed. If the exposure is small andthe length of time is short (1/2 hour to 1 hour), then a direct
pulp cap with CaOH followed by a restoration is the treatment
of choice.
21. C. Perform the amputation at a more apical levelUncontrolled bleeding is a sign of inflamed pulp tissue. The
radicular pulp must be uninflamed for the success of this
procedure. It is not uncommon to find uninflamed pulp at a
more apical level, especially in cariously exposed teeth. If
bleeding does not stop even after more apical amputation,
hemostatic agents are used as a compromise treatment. These
are closely monitored and if vitality is lost, apexification
(pulpectomy) procedures should be instituted. Pulpotomy is
removal of a portion of the pulp. The common Indicationsinclude: Cariously exposed deciduous teeth -> with healthy
radicular pulps. Traumatic or carious exposure of permanent
teeth with undeveloped roots. •An alternative to extraction
when endodontic treatment is not available. Emergency
treatment in permanent teeth with acute pulpitis. Unfortunately,
pulpotomy procedures performed in fully developed permanent
teeth are not found to be successful. For this reason it is
regarded as a temporary procedure in these teeth.
22. A. Accidental exposure of the pulpPulp of a young child Pulp capping is the placing of a sedative
and antiseptic dressing on an exposed healthy pulp in order to
allow it to recover and maintain normal function and vitality.
The dressing most commonly used is CaOH2 (Dycal). Pulpcapping is overused in dentistry today. In reality it has only
very few indications for its use. Young pulps are more
vascularized and, therefore, more amenable to repair. Pulp
cappings are more successful if the exposure was accidental
(trauma or with a dental bur) as opposed to carious. In addition,
the exposure should only be pinpoint to expect success. Repair
is accomplished by the formation of a dentin bridge at the site
of exposure. Even a small carious exposure should have root
canal therapy for the best long-term prognosis. A tooth may
stay asymptomatic for several weeks after pulp capping has
been performed. However, this may be only temporary.
Unfortunately, if pulp capping fails and the tooth becomes
symptomatic, it may be difficult, If not Impossible, to treat with
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routine because of the severe calcifications in the root canal.
Perforations may occur during attempts to follow the
obliterated canal to gain patency to the apex. Note: Perforations
into furcations of multi-rooted teeth have the poorest prognosis.
Traumatic blows to teeth are also a cause for calcification of the
pulp space sometimes to a point where locating the canal is
very difficult. With primary teeth, trauma may cause
calcifications in the pulp chamber, which in turn cause a
yellowish discoloration of the tooth.
23. A. "Tugback" within 1 mm of working lengthSince studies show that solvent softening does not ultimately
result in a better apical seal, this time consuming procedure can
be reserved for the other indications listed on the front of the
card. This slight resistance to dislodgement is referred to as
"tugback." The cone should also have a definite apical seat -►
it should not be able to be pushed further apically. If the
preparation is properly flared, fitting the master cone is not a
time-consuming procedure. A gutta-percha cone the same size
as the file used last during preparation (MAF) is selected and
placed as far as possible into the canal, but not beyond the
working length. Once satisfactory tugback and apical
positioning appear to be obtained, a radiograph is taken toverify cone positioning. If an accurate determination and
careful enlargement have been performed, the x-ray will show
that the master cone reaches the most apical position of the
preparation or extends to a point just short of that (1 mm).
When the cone is slightly short, the pressure of condensation
plus the lubricating action of the sealer wilt be sufficient to
produce complete seating of the cone. If the cone is more than 1
mm from the radiographic apex, discard the cone and fit a
smaller one or instrument more in the apical third. The main
reason for recapitulation (using your MAF after each increase
in file size) during instrumentation of the canal is to clean the
apical segment of the canal of any dentin filings that were not
removed by irrigation.
24. D. The tooth responds to thermal testsThis indicates inadequate debridement as a pulpless tooth
should not respond to any stimuli. The most important
consideration before filling a root canal is proper cleaning
(debridement) and shaping (instrumenting) of the canal. Once
the canal is obturated, any organisms that have entered the
periapical tissues from the canal are eliminated by the natural
defenses of the body. Objectives of root canal obturation: To
develop a fluid-tight seal at the apical foramen Complete filling
of the root canal space To create a favorable biologic
environment for the process of tissue healing In endodontic
treatment the importance of canal obliteration (filling) is second
only to canal debridement. Approximately 40% of failures arebelieved to be caused by incomplete obliteration of the root
canal. If the canal is not filled, tissue fluid and microorganisms
from the periapical tissues are able to enter the voids, with
failure as the ultimate result. However, if an accessory canal is
not totally filled during obturation, the appropriate treatment is
to observe the tooth and evaluate every three months. After
endodontic therapy is completed on a tooth with a periapical
radiolucency, it usually takes 6-12 months before marked
reduction in the size of the radiolucency is evident on an x-ray.
Desired periapical tissue changes include regeneration of
alveolar bone, deposition of apical cementum, and re-
establishment of the PDL
25. A. Pseudomonas.
The microorganisms identified in periradicular infections of
endodontic origin are similar to bacteria isolated and identified
from within the root canal. Gram negative anaerobic micro
organisms are the main causative agent of endodontic
infections while pseudomonas is aerobic. Among aerobes alpha
hemolytic streptococci were the most commonly recovered
microorganism.
26. A. Eucalyptol is the reagent of choice to dissolve gutta-
perchagutta-percha is slightly soluble in Eucalyptol.
Highly concentrated chloroform is very effective but should be
used with caution. Its vapor is potentially hazardous so it is
dripped directly in the canal avoiding excessive flooding. Other
chemicals which can dissolve gutta-percha to a varying degree
include: xylol, halothane, benzene, carbon disulfide, essential
oils, methyl chloroform and white rectified turpentine. If a
gutta-percha cone has passed beyond the apex then a file must
be used beyond the apex in order to avoid breakage of the cone.
A broken cone in the periapical area may result in an
orthograde re-treatment failure. Techniques to remove gutta-
percha include: Rotary removal, Ultrasonic removal, Heat
removal, Heat and instrument, removal, File and chemicalremoval. Gutta-percha points may be disinfected by placing
them in a 5.25% NaOCI solution for one minute. A glass bead
sterilizer can sterilize endodontic files in 15 seconds at 220° C
(428° F).
27. D. It is also an excellent Irrigation solutionit has a limited value as irrigation solution. The decalcifying
process induced by EDTA is self-limiting and stops as soon as
the chelator is used up. Chelating agents are used to aid and
simplify preparation for very sclerotic canals after the apex has
already been reached with a fine instrument. These agents act
on calcified tissues only and have little effect on periapical
tissue. Their action is to substitute sodium ions, which combine
with the dentin to give soluble salts for the calcium ions that arebound in less soluble combination. The edges of the canal are
thus softer, and canal enlargement is facilitated. EDTA will
remain active in the canal for 5 days If not inactivated. For this
reason, at the completion of the appointment the canal must be
irrigated with a sodium hypochlorite (NaOCI) containing
solution. EDTAC is EDTA with the addition of Cetavlon, a
quaternary ammonium compound. It has greater antimicrobial
action than EDTA. However, it has greater inflammatory
potential to tissue as well. The inactivator for EDTAC is
NaOCI. RC-PREP combines the functions of EDTA plus urea
peroxide to provide both chelation and irrigation. The foamy
solution has a natural effervescence that is increased by
irrigation with NaOCI to aid in the removal of debris.
28. C. To achieve glassy smooth walls of the canalClean shavings are difficult to see on a file. The attainment of a
clean irrigating solution is considered an inaccurate way to
determine the end point of debridement. Debridement is
defined as the removal of foreign material and contaminated or
devitalized tissue from or adjacent to a traumatic infected lesion
until surrounded healthy tissue is exposed. Chemomechanical
debridement of the root canal system is the most crucial aspect
of root canal treatment. Complete debridement of the canal is
the most effective means to reduce root canal microorganisms.
It can be carried out in various ways as the case demands, and
may include instrumentation of the canal, placement of
medicaments and irrigants and / or surgery. The most common
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cause of root canal failure is incompletely and inadequately
disinfected root canal systems. The second most common cause
of failures of root canals is leakage from a poorly filled canal.
This is common even after apical curettage. Example: Root
canal treatment performed on a tooth with apical curettage of a
lesion that was found to be a cyst. Three years later the lesion is
even bigger than it was before. The most likely cause of this
failure is leakage from a poorly filled canal. When a canal is
properly prepared, any of the accepted methods of filling willalmost certainly produce a successful result (as long as the
canal is completely filled).
29. B. Permits restoration to withstand occlusal forces.
30. D. All of the aboveThe engine driven instruments, however, use only the reaming
motion. Nickel titanium instruments can be bom hand operated
and engine-driven. Generally, hand instrumentation is done by
either filing (push and pull) or reaming (repeated rotations).
Filing is a push-pull action with emphasis on the withdrawal
stroke. Its efficiency is greater with files than with reamers for
removing dentin because of the greater number of flutes in
contact with the canal walls during the rasping motion ofremoving the instrument. The appearance of the canal is
irregular and for this reason a canal prepared with this action
must be filled with gutta-percha in a condensation procedure.
Reaming is defined as the repeated clockwise rotation of the
instrument, particularly during Insertion. The appearance of the
canal is approximately round (this method is recommended if
using a silver cone to fill canal). Reamers are usually most
efficient for this function. Circumferential filing is a push-pull
action with emphasis on scraping the canal walls to create a
smooth, tapered preparation. It is a method of filing whereby
the instrument is moved first towards the buccal side of the
canal, then reinserted, and removed slightly mesially. This is
done all the way around the tooth until all the dentin walls have
been planed. This technique enhances preparation when aflaring method is used.
31. D. Long history of successful usageThis alone outweighs its disadvantages of staining, slow setting
time, non-adhesion and solubility. The primary function of a
root canal sealer is to fill in the discrepancies between the core-
filling material and the dentin wall. In fact it is said that it is
more important than the core filling material. Other purposes or
functions of a root canal sealer include: To act as a lubricant,
facilitating placement of the gutta-percha To form a bond
between the filling material and the dentin walls To exert
antibacterial activity (some exert more than others). This
activity is the highest In the period of time Immediately after
Its placement Most root canal sealers are some type of zinc
oxlde-eugenol cement and are capable of producing a seal
while being well-tolerated by periapical tissues. All sealers
display some degree of radiopaclty (caused by metallic salts in
the sealer); therefore their presence can be demonstrated on a
radiograph. This is an important property, since it may disclose
the presence of accessory canals, resorptive areas, root
fractures, and the shape of the apical foramen and other
structures of interest. After filling a tooth with gutta-percha, if
you see a horizontal line of material (gutta-percha or sealer)
extending both mesial ly and dlstally from the canal to the
periodontal ligament space, this is Indicative of a root fracture.
32. D. Its absorption is faster than the plain gut sutures.
Chromic gut sutures consist of plain gut treated with chromium
trioxide this result in delayed absorption rate. Evidence indicate
that plain gut is more biocompatible with oral soft tissues than
is chromic gut. Collagen is basic component of plain gut suture
material. The collagen is treated with diluted formaldehyde to
increase in strength.
33. C. Round In shapeStudies have shown that the action of using the instrument,
rather than the instrument used, determines the general shape of
the canal preparation. Therefore, a reaming action produces a
canal that is relatively round In shape while a filing action
produces a canal that is irregular In shape. A canal should be
instrumented and shaped so that it has a continuously tapering
funnel shape. The widest diameter would be at the canal
opening and the narrowest at the dentinocemental junction (.5
to 1.0 mm from the radiographic apex). This is where all teeth
should be filed to and filled to (ideally).
34. C. BroachesThe barbs are notched out of the instrument shaft and represent
a weakened point If the broach is not used with the utmost of
care or if it is forced apically, the barbs wilt be bent and willengage the walls, making removal difficult.
K-type instruments: Flies are the most useful instruments in
for the removal of hard tissue in canal enlargements. They are
manufactured by twisting a blank, which is a square rod,
producing a series of cutting flutes. The action used for placing
this type of file into a canal should resemble a clockwise-
counterclockwise motion with pressure directed apically (can
be a filing or reaming action). These files are the strongest of
all files and cut the least aggressively. A modifcation to this
type of file is the K-flex file. Reamers are manufactured in a
manner similar to files, only they have fewer flutes. They are
used in canal preparations to shave dentin with a reaming
action only. They remove intracanal debris with clockwise
reaming action. They are also used to place materials into theapical potion of the canal by using a counterclockwise rotation.
H-type Instruments: Hedstrom flies are manufactured by using
a sharp, rotating cutter to gauge triangular segments out of a
round blank shaft. This produces a very sharp edge and
therefore an effective cutting instrument. If used carefully, with
filing action only, it will successfully plane the dentin walls
much faster than K-type files or reamers. A modification of this
file is the S-file. All of the above are made of stainless steel.
35. D. Polymorphonuclear (PMN) LeucocytesThe onset of pulpal inflammation is an insiduous process and is
characterized by a chronic cellular response (plasma cells,
macrophages and lymphocytes). There is no direct exposure of
the pulp to dental caries and the response, therefore, is not
acute. After pulp exposure, the acute inflammatory cells
(mainly PMN cells) are chemotactically attracted to the area.
Histologically, the tissue is likely to show signs of acute
inflammation near the site of the exposure and a band of
chronic inflammatory cells between the acute inflammation and
the underlying normal pulp. The response of vital pulp to
microbial Invasion is very resistant. You can have an idea
about its resistance from the observation that even after two
weeks of traumatic exposure of the pulp, only 2 mm of the
coronal pulp may "give in* to microorganisms. Non-vital pulp,
incontrast, is a "fertile ground" for the growth of
microorganisms. Carious exposures in permanent teeth
generally require root canal treatment. Immature (open apex)
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permanent teeth with carious exposures can be treated by pulp
capping or pulpotomy procedures. Pulp capping is not
recommended in primary teeth with carious exposures due to
its high failure rate and because pulpotomy, having similar time
requirements, has shown to be very successful. Pulp capping
can be done, however, in mechanical exposures.
36. B. A vertical fracture of the toothRadiographic examination seldom reveals the fracture because
the crack is usually parallel to the x-ray film. One of the most
puzzling and frustrating dental conditions involving the
possible need for endodontic treatment is the cracked tooth
syndrome. Symptoms from this condition usually are
characterized by a sharp but brief pain occurring unexpectedly
only when the patient is chewing. Having a patient bite
forcefully on a bite stick and noticing the cusps that occlude
when the pain occurs will aid in the location of the offending
tooth. Vertical fractures through root structure, however, have
an almost hopeless prognosis. If the fractured segment can be
removed and gingivoplasty and alveoloplasty performed,
treatment can be successful. However, unrealistic or
overambitious case selection leads to a high degree of failure.
When an anterior tooth fractures, it generally occurs in a morehorizontal plane and may show up on the x-ray. The cause is
usually accidental trauma such as a blow to the jaw or teeth. If
the fracture line is not too far down the root of the tooth, it may
be able to be saved with a root canal and a crown. Inlays have
been shown to be a cause of fractures. If a patient complains of
pain on mastication since the placement of an inlay, suspect a
fractured cusp (using a bite stick wilt help determine which
cusp may be fractured).
37. D. 0.005 – 0.01 microns.Nano fillers are about 7 mm range and used in modern
composite as they penetrate the typical key hole etch pattern of
enamel as well as smallest dentin channels. Microdentristry
uses A12O3 particles of 27 micron range.New composites are being developed with nanofillers that
ranges in size from 0.005 – 0.01 micron which is below the
wavelength range for visible light (0.02 – 2 µm) Because these
particles do not interact with visible light they do not produce
scattering or significant absorption.
38. A. A submarginal curved flapA submarginal curved flap also called semilunar flap
This half-moon shaped flap is raised with a curved horizontal
incision in the mucosa or attached gingival with the concavity
towards the apex. Although it's simple and does not impinge on
the surrounding tissue, the disadvantages outweigh its
advantages. These include: 1) Limited access and visibility 2)Tearing of comers of the incisions when an attempt is made to
improve accessibility by stretching the flap 3) If somehow a
lesion is found to be bigger than anticipated, the incisions come
to lie over the bony defect. Healing occurs by scarring 4) Its
extent is also limited by attachments (e.g., frenum, muscles
etc.) Submarginal triangular and rectangular flap (Ochsenbein-
Leubke) requires at least 4 mm of attached gingiva and a
healthy peridontium. It is raised by a scalloped incision in the
attached gingiva with one or two vertical incisions. Less risk of
incising over bony defects and no post-surgical recession of
gingiva. Its disadvantages include hemorrhage from the cut
margins and scarring. Access and visibility is better (and
acceptable) than semilunar flap but not as good as full
mucoperiosteal flap. Full mucoperiosteal flap allows maximal
access and visibility. It is raised from the gingival sulcus
(elevating gingival crest and interdental gingiva). This wide
outline of the flap precludes any incisions over bony defects
and allows various periodontal procedures including curettage,
root planing and bone re-shaping. A large flap may be difficult
to reposition, suture and make alterations. Post surgical
gingival recession is also a possibility.
39. A. Tooth socket
40. A. A conical shaped probingIn "blow-out type" and "sinus tract type" probings, another clue
for diagnosis is a non-vital (necrosed) pulp -» these two lesions
can completely heal after root canal treatment. Acute or blow-
out lesions -» a tooth with this type of lesion will show normal
sulcus depth all the way around the tooth until the area of the
swelling is probed. At this point, the probe drops suddenly, to a
level near the apex. The probing depths in all other areas are
within normal limits. Periodontal lesions characteristically
show bone loss which begins at the crestal bone level and
progresses apically. Hence probing defect would be conical in
shape. This type of lesion may not be amenable to root canaltreatment alone even if it is associated with a pulpless tooth.
However, endodontic treatment must be completed prior to
tackling the periodontal problem.
A narrow sinus tract type lesion --> the probing reveals normal
depths all around the tooth except at one very narrow area.
Here, the probe can pass down the root surface to some
distance and sometimes even to the apex. The tooth is pulpless
(non-vital). Once the root canal treatment is completed, the
lesion heals within one week. A perio-endo abscess is a
combined lesion. The lesion usually demonstrates radiographic
involvement of the periodontium and the apex of the involved
tooth. A common clinical finding of a periodontal problem is
pain to lateral percussion on a tooth with a wide sulcular
pocket.
41. D. Threaded screw posts are preferred over parallel
sided and tapered postsThese may actually increase the chance of fracture. The
parallel-sided posts are preferred. Options available when
restoring endodontically treated posterior teeth: Restoration of
occlusal opening only -» in rare Instances the access opening
and caries destruction do not encroach on the cusps and
marginal ridges. These teeth may be restored with an occlusal
amalgam; however, a cuspal coverage restoration would
provide protection from fracture.
Onlay restoration -> In most cases it is Imperative that root
canal treated teeth be protected from fracture by a cusp-
coverage type of restoration. The minimum (most conservative)
preparation should be for an onlay covering the cusps and
marginal ridges.
Crown -» a full-coverage crown is preferred when the
remaining coronal tooth structure does not afford sufficient
tooth structure for an onlay.
Crown with post and core -» to reinforce the treated tooth and
provide suitable coronal tooth structure for an optimum crown
preparation, the use of a post and core is often indicated. Be
very careful when placing posts. Perforations and vertical root
fractures can occur. If you are performing a pulp chamber-
retained amalgam, you need to place amalgam 3 mm Into each
canal for retention. Endodontically treated posterior teeth are
more prone to fracture than untreated posterior teeth due mainly
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to the destruction of the coronal tooth structure -* they have
reduced structural integrity.
42. C. Of the most apical portion of the rootAn apicoectomy is best accomplished by obliquely resecting
the most apical portion of the involved root. If a tooth has had
previous endodontic therapy and becomes reinfected, it is
usually best to try and retreat it conventionally -> remove
filling material, debride the canals, and refill. However, if the
tooth has been restored with a post, core, and crown then apical
curettage, apicoectomy, and a retrofill should be performed.
Indications for apicoectomy: A reverse filling needs to be
placed. It is necessary to gain access to an area of pathosis. The
poorly filled apical portion of the root is to be removed to the
level of canal obliteration. Indications of peiiradicular surgery:
Non negotiable canal, blockage or severe root curvature in
which non-surgical treatment is impossible. Complications
arising from procedural accidents (e.g., separation of
instruments, ledging and/ or perforations) which cannot be
handled without surgical exposure of the site. Failed
treatment due to irretrievable posts or root fillings. Horizontal
apical fractures in which apical end of the pulp becomes
necrotic. Biopsy -> to diagnose non-odontogenic causes ofsymptoms, (e.g., patient with a history of previous malignancy,
lip parsthesia or anesthesia).
43. C.The size of the pulpAs the pulp ages there is a decrease in reticulln fibers (the pulp
becomes less cellular and more fibrous). The size of the pulp
also decreases because of the continued deposition of dentin.
As the pulp ages there is an increase in the number of collagen
fibers and calcifications within the pulp (called denticles or
pulp stones). The pulp contains both myelinated and
unmyelinated nerve fibers. They are afferent and sympathetic.
The myelinated fibers are sensory and the unmyelinated fibers
are motor -» they play a role in the regulation of the lumen size
of the blood vessels. Proprioceptors (which respond to stimuli
regarding movement) are not found in the pulp. The only type
of nerve ending found in the pulp is the free nerve ending,
which is a specific receptor for pain. Regardless of the source
of stimulation (heat, cold, pressure), the only response will be
pain. Pulp stones are associated with chronic pulpal disease -
»from advanced carious lesions or large restorations.
44. C. PredentinImmediately adjacent to the odontoblast layer in the pulp, 10-
47 iim of the dentin matrix remain unmineralized. If this
unmineralized layer of dentin is lost (e.g., due to trauma or
infectious process) it predisposes the dentin to internal
resorption by odontoclasts.Mantle dentin -> is first-formed dentin which is laid before
odontoblast layer gets organized. Hence the pattern of
deposition and size of collagen fibers is different from
circumpulpal dentin.
Clrcumpulpal dentin -> represents most of the dentin which is
formed.
Secondary dentin -» forms after eruption of a tooth and
throughout life resulting in a gradual but asymmetric reduction
in pulp size.
Tertiary dentin or reparative dentin -» is an irregular and
disorganized layer of dentin laid down in response to any
injurious / irritant stimuli. Dentin formation is the primary
function of pulp. Other functions include:
Induction -» forms dentin which in turn induces enamel
formation
Nutrition -» dentinal tubules are linked to the pulp which
maintains its hydration and formation of peritubular dentin.
45. D.Digital Fibre optic trans-illumination
46. C. Saliva can allow storage of the tooth up to 6 hours'This is false; saliva is hypotonic and can therefore allow
storage up to 2 hours. Maximum storage time of 6 hours isreported for milk. Note: All of the other statements on the front
of the card are true and must be remembered. Five factors that
are critical to the management of traumatic avulsion injuries to
teeth: Time -> the time interval from injury to replacement of
the tooth is a major factor in the maintenance of ligament
viability and subsequent root resorption. Teeth replanted within
30 minutes have been reported to exhibit very little resorption,
whereas most of the teeth replanted after 2 hours show a lot of
external root resorption (which is the main cause of failure of
replanted teeth).
Storage media -» if the tooth cannot be immediately replanted,
the proper storage of the tooth can favorably influence the
viability of PDL cells. Milk is considered best for this purposebecause of its near neutral pH (6.5-6.8) and osmolality,
conducive for the survival of cells. Other storage media are
physiologic saline and saliva.
Tooth socket -» should not be damaged by curettage or forceful
replantation.
Splint stabilization -» a splint that allows the physiologic
movement is placed for a maximum of 2 weeks. This time
period allows for the initial reattachment of the periodontal
ligament fibers.
Root surface -» should not be scraped, dried, or manipulated
with caustic chemicals. The above information changes when a
tooth has been out of the mouth for more than 2 hours -*
mainly the treatment of the tooth socket and root surfaces as
well as the time for splint stabilization.
47. D. Curettage of the socket to remove periapical pathoslsThis is probably unnecessary. In fact, socket wall should be
minimally manipulated. Intentional replantation implies that a
tooth requiring endodontic therapy is purposely removed from
its socket, some type of canal or apical preparation and / or
filling is performed, and the tooth is returned to its original
socket. Indications for intentional replantation (also called
replant surgery): When routine endodontic therapy of a tooth is
Impractical or Impossible When an obstruction of a canal is
present, such as a broken instrument or a calcification, and
periapical surgery is impractical (a lower molar with the
mandibular canal in close proximity). When perforating
Internal or external resorption is present, yet surgery isimpractical When a previous treatment has failed but
nonsurgical treatment or surgery is impractical. Intentional
replantation should be considered only when there's no other
alternative treatment to maintain a "strategic" tooth. Long term
follow up is required to monitor for complications including
periodontal defects and ankylosis with replacement resorption.
48. C. Leave the tooth and come to the office ImmediatelyReplantation of a primary tooth is not recommended because of
the potential danger to the permanent successor from sequels of
trauma (e.g., infection, ankylosis, or damage due to
manipulation during procedure itself). Proper management of
an avulsed permanent tooth that has been replanted within two
hours of the accident: Ten days to two weeks after replantation,
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the root canal is prepared (cleaned and shaped) and a calcium
hydroxide paste is placed into the canals. This paste is replaced
every three months for one year. If after one year, it appears
that resorption has reversed or stopped, a permanent gutta-
percha filling can be placed. Important: If a tooth is out of the
mouth for more than two hours : Ankylosis and external root
resorption will probably result within two years. Ankylosis
resulting from replacement would give a better prognosis than
external resorption, which lead to failure. Root canal therapy isperformed in its entirety prior to replantation. The tooth is
soaked In a 2.4% fluoride solution acidulated at pH 5.5 for 20
minutes or more. The fluoride will slow the resorptive process,
Gently curette blood clot out of the alveolar socket and Irrigate
with saline. Rinse tooth with saline, replant into socket, and
splint for 4-6 weeks. Resorption is the most frequent sequela to
replantation. Three different types of resorption have been
identified: surface, inflammatory and replacement (ankylotic
resorption). Replacement resorption refers to resorption of the
root surface and its substitution by bone, resulting In ankylosis.
49. C. Inflammation due to an infected coronal pulpThis condition is frequently precipitated by traumatic injury to
the tooth. Undifferentiated reserve connective tissue cells of thepulp are activated to form dentinoclasts, which resorb the tooth
structure in contact with the pulp. Internal (inflammatory)
resorption is usually asymptomatic and is discovered on
routine radiographic evaluation. The anatomic configuration of
the root canal is altered and increases in size with internal
resorption. It will appear as an irregular radiolucency anywhere
along the canal space. The tooth involved may respond to pulp
vitality tests.When internal resorption is detected, a pulpectomy
should be performed. Once the pulp tissue responsible is
removed, all resorption ceases. To "wait and see" may result in
sufficient destruction of the tooth to create a perforation of the
root. Typical radiographic appearance of internal resorption
Although, internal resorption can occur only when some of thepulp tissue is still vital, a negative sensibility test does not rule
out this etiology. Also remember that sometimes on a
radiograph, an external resorptive lesion can superimpose the
canal space to mimic internal resorption. In such cases, another
radiograph should be exposed at an angle to the tooth. The
radiolucent lesion inside the canal space will not shift.
50. B. Inflammatory resorptionBowl-shaped areas of resorption involving cementum and
dentin characterize external inflammatory root resorption. This
type of resorption is rapidly progressive and will continue if
treatment is not instituted. Since both a necrotic pulp and the
presence of bacteria are necessary components of inflammatory
resorption, the process can be arrested by immediate root canaltreatment. The tooth is opened and the canal is cleaned and
shaped. A calcium hydroxide paste is placed in the canal. This
is replaced every three months for one year. If after one year, it
appears that the resorption has stopped, a permanent root canal
filling (gutta-percha) can be placed. A calcium hydroxide-based
root canal sealer is strongly recommended. Surface resorption
is caused by acute injury to the periodontal ligament and root
surface. If injury is not repeated, healing takes place with new
cementum and PDL. Replacement resorption refers to
resorption of the root surface and its substitution by bone,
resulting in ankylosis. This is often seen in unsuccessful replant
cases. The etiology of external and Internal resorption:
External resorption -* periradicular inflammation, dental
trauma (resulting in damage to attachment apparatus),
excessive orthodontic forces, impacted teeth, bleaching of non-
vital teeth. Internal resorption -» dental trauma (resulting in
loss of vitality and subsequent infection), dental caries, pulp
capping with calcium hydroxide, cracked tooth.
51. B. periodontal cyst
52. C. Intentional replantation Is a viable alternative to
endodontic surgeryIntentional replantation is not a substitute for endodontic
surgery if it can be undertaken. All of the other statements on
the front of the card are true and must be remembered.
Transplantation is the transfer of a tooth from one alveolar
socket to another either in the same person or in another person
Orthodontic extrusion is defined as force-controlled vertical
tooth movement occlusally in the socket. Indications include
unbeatable subgingival pathoses e.g., cervical caries, cervial
fracture, periodontal defects, resorptive lesions and perforations
in the cervical area. Crown lengthening is a procedure used to
apically position the gingival margin and / or to reduce the
cervical bone. It is employed during the treatment of
subgingival caries perforations and resorptions. Rootsubmersion involves resection of tooth roots 3 mm below the
alveolar crest and then cover with a mucoperiosteal flap.
Indications include rampant caries, adverse periodontal
conditions and in cases that have had repeated prosthetic
failures. The submerged roots will prevent alveolar resorption
and maintain better proprioception. This is especially useful in
medically compromised or handicapped patients requiring
better denture control. Sometimes, this is also done to avoid
formation of an esthetic defect that may result after extraction.
53. C. Stieglitz forceps
54. D. "Pink" tooth Is considered to be pathognomonic of
replacement resorption
Traditionally pink tooth has been considered pathognomonic ofinternal resorption but it is not an uncommon feature of cervica
root resorption as well. It is characterized by a pinkish
appearance of the tooth due to growth of granulation
undermining the coronal dentin. Replacement resorption, which
accompanies dento- alveolar ankylosis resulting from extensive
trauma to the attachment apparatus of the tooth is characterized
by progressive replacement of the root by the bone.
Histologically, it shows direct contact between dentin and bone
with no intervening PDL or cemental layer. This condition's
pathognomonic signs are: Lack of mobility Metallic sound to
percussion Infra-occlusion of the involved tooth in the
developing dentition
55. C. Endodontic treatment followed by periodontic
treatmenttn a combined perio-endo lesion, endodontic treatment
generally takes precedence over periodontal management.
Combined endodomtic-periodontal therapy is widely used
because the anatomic and clinical connections between the pulp
and periodontal structures are close and numerous. In most
cases of this nature, endodontic procedures are preformed first
and, when necessary, are followed by periodontal measures. In
these cases, the value of precise pocket probing and correc
appraisal of the vitality of the pulp is crucial. In some doubtfu
cases, the better part of wisdom is to wait until after the
completion of the root canal therapy to see whether
spontaneous resolution (pocket closure and osseous fill-in) wil
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occur before surgical periodontal procedures are begun.
Periodontal therapy should be initiated first only in the case of
a primary periodontal lesion with subsequent secondary
endodontic involvement. A common clinical finding of a
periodontal problem is pain to lateral percussion on a tooth with
a wide sulcular pocket.
56. B. Chemical solutionsThe method of choice for sterilization of gutta percha is
chemical solutions. Gutta percha cones may be kept sterile in
screw-capped vials containing alcohol. To sterilize a gutta-
Percha cone freshly removed from the manufacturer’s box, one
should immerse it in 5.2% sodium hypochlorite for 1 min, then
rinse the cone with hydrogen peroxide and dry it between 2
layers of sterile gauze. It has been demostrated that 5.2%
sodium hypochlorite is more effective than sporicidin and as
effective as activated dialdehyde (cidex) for sterilizing guta-
percha cones.
57. B. The numbers of flutes on the blade are more in files
than in reamers.
58. C. Pulp & supporting tissue59. B. Establish drainageAn acute apical abscess is accompained by a severe local
reaction and, at times, a general reaction of systemic toxicity
such as elevated temperature, gastrointestinal disturbance,
malaise, nausea, dizziness and other symptoms related to
continuous pain and lack of sleep. To relieve this constant pain
as an emergency measure, one should establish drainage
through the root canal, preferably, and through the soft tissue
and bone, if necessary. The open-drainage technique is
preferable to one in which the prepared root canals are sealed,
followed by incision of the soft tissue and artificial fistulation
of the bone to establish drainage. Open root canals permit
drainage and frequently eliminate the need for a surgicalincision as well as the routine administration of oral antibiotics
and analgesics. The prognosis for the tooth is generally
favourable, depending on the degree of local involvement and
the amount of tissue destruction.
60. D. All of the above
61. C. Both a & b
62. A. Chronic open pulpitisChronic hyperplastic pulpitis or “pulp polyp” is a productive
pulpal inflammation due to an extensive carious exposure of a
young pulp. It is characterized by the development of
granulation tissue, covered at times with epithelium and
resulting from long-standing, low-grade irritation. Slow,progressive carious exposure of the pulp is the cause. A large
open cavity, a young, resistant pulp, and a chronic, low-grade
stimulus are necessary for the development of hyperplastic
pulpitis. Mechanical irritation from chewing and bacterial
infection often provide the stmulus. The condition is usually
symptomless and is generally seen only in the teeth of children
and young adults. The appearance of the polypoid tissue is
clinically characteristic; a fleshy, reddish pulpal mass pulpal
mass fills most of the pulp chamber or cavity or even extends
beyond the confines of the tooth.
63. C. Grey matter of spinal cord
64. B. Immature teeth
65. C. SuperoxolWalking bleach technique is used for bleaching a discolored,
endodontically treated tooth. Superoxol can be used alone or
mixed with sodium perborate into a paste for use in the
“walking bleach”. Superoxol is a 30% solution of hydrogen
peroxide by weight and 100% by volume in pure distilled
water. Sodium perborate is a stable, water soluble white
powder which decomposes into sodium metaborate and
hydrogen peroxide, relaeasing oxygen. When mixed into apaste with superozol, this paste decomposes into sodium
metaborate, water and oxygen. When sealed into the pulp
chamber, it oxidizes and discolors the stain slowly, continuing
its activity over a longer period of time.
66. D. Dentinal chips along with a & b
67. A. Proper instrumentation
68. A. Pain of pulpal originThermal testing involves the application of cold and heat to a
tooth, to determine sensitivity to thermal changes. A response
to cold indicates a vital pulp, regardless of whether that pulp is
normal or abnormal. When a reaction to cold occurs, the patient
can quickly point to the painful tooth. Cold can be applied inseveral different ways such as: Stream of cold air Ethyl
chloride spray/cotton pellet saturated with ethyl chloride Ice in
wet gauze/ ice pencils Carbondiozide (dry ice) snow – 780C
temperature.
69. B. Remineralization
70. B. Irrigation of root canal
71. B. Does not relate to the periodontal conditionCalcification of pulp tissue is a very common occurrence and is
unrelated to the periodontal condition of the tooth. In the
coronal pulp, calcification usually takes the form of discrete,
concentric pulp stones, whereas in the radicular pulp,
calcification tends to be diffuse. The cause of pulpalcalcification is largely unknown, Calcification may occur
around a nidus of degenerating cells, blood thrombi, or
collagen fibers. Many authors believe that this represents a
form of dystrophic calcification. Calcification may occur
around a nidus of degenerating cells, blood thrombi, or
collagen fibers. Many authors believe that this represents a
form of dystrophic calcification. Calcification replaces the
cellular components of the pulp and may possibly hinder the
blood supply. Luxation of teeth as a result of trauma may result
in calcific metamorphosis, subsequently causing partial or
complete radiographic obliteration of the pulp chamber.
72. B. It is not successful in wet field
73. D. Periphery, at the bottom
74. D. Provide straight line access to the apexThe objectives of access cavity preparation are:
1. To achieve straight or direct-line access to the apical foramen
or to the initial curvature of the canal.
2. To locate all root canal orifices
3. To conserve sound tooth structure.
A properly prepared access cavity creates a smooth, straight-
line path to the canal system and ultimately to the apex. When
prepared correctly, the access cavity allows complete irrigation
shaping and cleaning and quality obturation. Ideal access
results in straight entry into the canal orifice, with the line
angles forming a funnel that drops smoothly into the canal.
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Modifications of the outline form may be needed to facilitate
location of canals and to create a convenience form.
75. B. Compaction method
76. B. Bacterial
77. B. PacemakerElectric pulp tests are contraindicated in patients who have
cardiac pacemakers because they can interfere with the function
of the pacemaker. Attachments that reduce the amount of
surface contact necessary to conduct the electric stimulus are
available, and bridging the tip to a small area of tooth structure
with an explorer has been suggested. However, use of even this
small electric stinulus in patients with pacemakers is not
recommended; any such risk would outweigh the benefit. The
same caution holds true for electrosurgical units.
78. A. middle 1/3rd premolars
79. A. At the same appointment
80. A. 2 hoursAvulsed tooth may be stored in saliva for upto 2 hours. Storage
of avulsed teeth in saliva for 2 to 3 hours causes swelling andmembrane damage to periodontal ligament cells owing to
saliva’s nonphysiologic osmolality. The nonphysiologic
osmolality, less favorable composition and presence of
microorganisms makes saliva a less desirable storage medium
for the avulsed tooth. However, it is preferable to dry storage
for short peroids.
81. A. Root crown ratio
82. B. Chemical solutions
83. A. Sodium hypochloriteThe ultrasonic instrument consists of a piezoelectric ceramic
unit that generates ultrasonic waves, which activates a
magnetostrictive stack hand piece. The hand piece holds a K-file or a diamond file that produces movements of the shaft of
the file when activated. This oscillating movement produces the
cutting edge of the file. Sodium hypochlorite irrigant solution is
delivered alongside the file into the root canal.
84. C. H2O2 & sodium perforate bleaching
85. D. None of the above
86. B. Used to stabilize periodontally weakened teeth with a
poor ‘crown:root’ ratioAn endodontic implant is a metallic extension of the root, with
the object of increasing the root-to-crown ratio to give the tooth
better stability in the arch. Endodontic implants are useful for
treatment of- Periodontally involved teeth requiringstabilization. Transverse root fractures. Pathological resorption
of root apex (due to abscess). Pulpless teeth with short roots.
Root affected by internal resorption.
87. A. Penicillin
88. C. Culture for 48 – 96 hrs at 37°°°° C and plating of
positive findings
89. B. HermannHermann introduced Ca(OH)2 as a successful pulp capping
agent in 1930. He demonstrated the formation of secondary
dentin over the amputation sites of vital pulps capped with
Ca(OH)2.
90. C. Biting on rubber wheel
91. D. Triangular
92. B. Maxillary central incisorThe teeth most vulnerable to injury in order of frequency are-
1.Maxillary central incisors.
2. Maxillary lateral incisors.
3. Mandibular incisors.
Commonly observed dental trauma is fracture of enamel, or ofenamel and dentin, but without pulp involvement.
93. B. 0.12 to 0.38 mm
94. A. Fibrinolysin and polymorphonuclear leukocytes
95. B. Zone of irritationFish described the reaction of peri-radicular tissues to noxious
products of tissue necrosis, bacterial products, and antigenic
agents into 4 well defined zones of reaction.
ZONE CHARACTERIZED BY
Zone of infection PMNs
Zone of contamination Round cell infiltration
Zone of irritation Macrophages and osteoclasts
Zone of stimulation Fibroblasts and osteoblasts
96. C. 08 to 150
97. D. Full crown preparationsPalpal injuries may be caused by-
1. Heat generated by injudicious cutting.
2. Restorative materials having high thermal conductivity in the
absence of proper pulp protection.
3. Chemical ingredients of restorative materials.
4. Galvanic currents.
5. Ingress of microbes due to microleakege.
98. C. Post space preparation
The two popular engine-driven instruments are-1. Gates Glidden drill: It is used for initial opening of canal
orifices and deeper penetration, in both straight and curved
canals. 2. Piezo reamer: It is most often used in preparing the
coronal portion of the root canal for a post and core.
99. A. Notched
100. A. Gram positive organisms
101. D. EDTA with urea peroxideRC-Prep is a chelating agent used for removal of smear layer.
RC prep is composed of EDTA and urea peroxide in a base of
carbowax. It is not water soluble. Its popularity in combination
with sodium hypochlorite is enhanced by the interaction of urea
peroxide in RC-Prep with sodium hypochlorite, producing abubbling action thought to loosen and help float out dentinal
debris.
102. A. Cell free zone
103. B. Pulp polyp104. A. Pulp is bounded by rigid dentinThe encasement of pulp in the dentin creates an environment
that allows only small amounts of intracellular accommodation
of exudate during inflammatory reactions. This inability of the
pulp to swell creates an abnormally high pressure in an area of
Inflammation, with interruption of blood flow due to collapse
of the pulpal veins which Results in anoxia and localized
necrosis.
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105. D. All of the above
106. C. Presence of inflammation in the apical portion of
the periodontal ligament
107. A. Flare the walls of root canalsHedstroem files (H – files) are manufactured from a round
stainless steel blank, machined to produce spiral flutes
resembling cones of a screw. H-files have higher cutting
efficiency than K-files. They cut in one direction only(retraction). H-files are fragile and fracture easily.
108. D. Fibroblasts
109. D. 5 seconds
110. B. Root canal treatment
Condition of the pulp Treatment indicated
Pulp exposure not over
24 hours
Pulp capping
Pulp exposure within 72
hours
Pulpotomy/Apexogenesis
Pulp exposure greater
than 72 hours
Pulpectomy/ Apexification
111. B. Penicillin or erythromycin
112. C. Since it will reduce the flora
113. A. Apical thirdThe primary gutta percha should seal the apical canal
approximately 1 mm short of the pulpoperiapical juncture.
The purpose of fitting the primary cone short of the canal apex
is to avoid inadvertent overfilling of the root canal during
condensation.Gutta perchan can also be used as a root end
filling material. At least 5 mm of gutta percha should be
retained apically in case of post space preparation.
114. D. Produce a hermetic seal when set
115. B. Removal of broken instruments
116. B. 3 mmIndications for apical resection/root end resection/apicoectomy
are- 1. Persistent symptoms and continued presence of a
periradicular lesion.
2. Interradicular posts.
3. Irretrievable root canal filling material.
4. Procedural accidents (perforations etc).
5. Apical root fracture.
Two important points to be considered while doing this
procedure are-
1. Extent of apical resection-removing 3mm of the root tip.
2. Bevelangle-root resection must be done perpendicular to thelong axis of the root.
whenever possible. Bevel greater than100 are undesirable and
structurally destructive.
117. C. Streptococci and staphylococci
118. C. Lentulo
119. C. Flutes of a Hedstroem file in reverseMc Spadden Compactor is a type of thermoplastic gutta percha
delivery system, where a large cone of gutta percha is placed
into the root canal and a special bur –the compactor-is used in a
low speed hand piece to both plasticize it and pack it against
the root canal walls. It is similar to a Reverse Hedstroem file
that drives the material back into the canal rather than removes
it. It can be best used in canals of size 50 and larger canals and
also in those that are relatively straight. Formerly, it was very
popular for filling teeth having resorptive defects. Its major
disadvantage is that it can not be used in narrow and curved
canals.
120. C. Fine argyrophillic fibers
121. C. Loss of apical seal
122. D. Carbamide peroxideNight Guard/Mouth Guard bleaching technique is widely used
as a hone bleaching technique. Carbamide peroxide is generally
used.
Intracoronal bleaching Sodium perborate
Extracoronal bleaching Hydrogen peroxide &
Carbamide peroxide
123. B. Streptokinase
124. B. Apical third of the root
125. D. Mineral Trioxide Aggregate (MTA)MTA is a root end filling material. The main molecules present
in MTA are calcium and phosphorus ions. MTA is a newmaterial developed for endodontics that appears to be a
significant improvement over other materials for procedures in
bone. It is the first restorative Material that consistently allows
for the overgrowth of cementum, and it may facilitate the
regeneration of the periodontal ligament. It is mixed with a
sterile liquid such a saline or local anaesthetic solution on a
sterile glass slab.
126. B. Fibrin and epithelial cells
127. D. Magnesium carbonate
128. A. Cemented.
129. B. 10
130. C. 6.5 and below
131. A. Periapical abscessPeriapical abscess/Dento-alveolar abscess/Alveolar abscess is
an acute or chronic suppurative process of the dental periapical
region. It usually arises as a result of infection following
carious involvement of the tooth and pulp, but it also does
occur after traumatic injury to the teeth resulting in necrosis of
the pulp and in cases of irritation of the periapical tissues either
by mechanical manipulation or by the application of chemicals
in endodontic procedures. Acute exacerbation of a chronic
periapical lesion is called a Phoenix abscess.
132. C. None of the above133. A. Prevention
134. A. The pulp is necroticApexification is defined as a method of inducing apical closure
by the formation of osteocementum or a similar hard tissue.
Treatment by apexification should be tried when the pulp has
died in a developing tooth with incomplete root formation.
Ca(OH)2 paste is used. The calcific barrier at the root apex
serves as a stop for a gutta percha filling and ensures an
adequate seal.
135. C. 2 -3 mm
136. A. Hyaline bodies
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137. B. Its antimicrobial propertyThe antiseptic action of Ca (OH)2 is probably because of its
high pH and its leaching action on necrotic pulp issue.
Ca(OH)2 causes a significant increase in pH of circumpulpal
dentin when the compound is placed in the root canal.
Ca(OH)2 paste is best used as an intracanal medicament when
one anticipates an Excessive delay between appointments,
because it is efficacious as long as it remains within the root
canal.
138. C. The blood stream
139. B. 6.6%
140. C. Enamel, Dentin and Pulp are involvedClassification of Ellis and Davey (1960) is as follows-
Class I Simple fracture of the crown involving little or no
dentin
Class II Extensive fracture of the crown involving
considerable dentin, but not the pulp
Class III Extensive fracture of the crown involving
considerable dentin and exposed dental pulp
Class IV The traumatized tooth which becomes non-vital
with or without loss of crown structure.Class V Loss of tooth
Class VI Root fracture with or without loss of crown
structure
Class VII Displacement of a tooth without fracture of crown
or root
Class
VIII
Fracture of crown enmass
Class IX Traumatic injuries of deciduous teeth
141. B. MB
142. B. 873.63
143. C. Barbed broachK file – K-file is an ISO Group I instrument traditionally made
from a square blank. H file – H-type files are made by cutting
spiraling flutes into the shaft of a piece of a round, tapered,
stainless steel wire. They cut in one direction only and are very
efficient in cutting. Barbed broach- Barbed broaches are short-
handled instruments used primarily for vital pulp extirpation.
They are also used to loosen debris in necrotic canals or to
remove paper points or cotton pellets.
Reamer – Reamers are instruments that ream. It is specificically
a sharp edged tool for enlarging or tapering holes. They cut by
reaming action.
144. D. Black
145. B. Anachoretic pulpitisAnachoresis refers to the attraction or fixation of blood-borne
bacteria in areas of inflammation. One probable cause of this
phenomenon is increased capillary permeability in the
particular area. Anachoretic pulpitis probably occurs in a
clinically insignificant number of cases of pulpitis compared
with the number of cases occurring as a result of dental caries.
146. C. 6 to 12 months
147. D. All of the above
148. D. All of the aboveOther contraindications include:
A non-strategic tooth -»a tooth not in occlusion A tooth with
massive Internal or external resorption A tooth that has a canal
unsuitable for instrumentation or for surgery (i.e., broken
instalments, dentinal sclerosis, sharp dilacerations, etc.) A
medical condition such as hemophilia is not a contraindication
to conventional endodontic therapy. However, it is strongly
recommended that a dentist obtain clearance from the patient's
physician prior to treatment. Any teeth not contralndlcated are
excellent candidates for successful endodontic therapy.
Example of a special case: A previously traumatized tooth mayshow complete obliteration of the pulp chamber and canal. The
periodontal ligament may appear normal. The patient will be
asymptomatic and the tooth will not respond to pulp vitality
testing. The treatment of choice is to observe as long as the
tooth remains asymptomatic and no periapical changes are
evident.
149. D. None of the above
150. A. Porphyromonas and PrevotellaThese species, which were previously classified under
bacteroids species merited a separate genus due to their distinct
characteristics. Predominant bacterial species isolated from
Infected root canals include: Eubacterium speciesPeptostreptoccus species ■ Fusobacterium species
Porphyromonas species Prevotella species Virulence factors
which play a role in periradlcular pathosis include:
Llpopolysaccharide (LPS) -> found on the surface of gram
negative bacteria Enzymes -+ neutralize antibodies and
complement components
Extracellular vesicles -»involved in bacterial adhesion,
proteolytic activities, hemagglutination and hemolysis
Fatty acids -* affect chemotaxis and phagocytosis
A vital pulp resists bacterial invasion. Even if the pulp is
exposed to microorganisms for 2 weeks, the penetration of
bacteria may extend no more than 2 mm into the pulp. In
contrast, non-vital pulp is a fertile ground for the growth of
microorganisms and leads to necrosis. RememberStreptococcus spp. may not be as important in the progress of a
carious lesion (leading to pulp exposure) as much as it is, in the
initiation of the lesion. Strict anaerobes are found to play a
significant role in periapical pathoses.
151. A. 2.0% Sodium nitriteItems sensitive to elevated temperatures can not be autoclaved.
Autoclaving tends to corrode the steel neck and shank portions
of some diamond instruments and carbide burs. For autoclave
sterilization, burs can be protected by keeping them submerged
in a small amount of 2% sodium nitrite solution.
152. D. Presence of a fistula
153. D. Submaxillary space
154. D. Mandibular lateral incisorClass-III restorations are indicated for defects located on the
proximal surface of anterior teeth that do not affect the incisal
edge. A. lingual access preparation of the distal surface of the
maxillary canine is recommended because the use of amalgam
in that location is more likely. Usually the outline form
includes only the proximal surface, however, a lingual dovetail
may be indicated if one existed previously or if additional
retention is needed for a larger restoration.
155. A. 16 mm
156. C. Phoenix abscess
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157. B. Permit chemical bonding between resin and enamelAcid –etching transforms the smooth enamel into a very
irregular surface, and also increases its surface free energy.
When a fluid resin-based material is applied to the irregular
etched surface, the resin penetrates into the surface, aided by
capillary action. Monomers in the material polymerize, and the
material becomes interlocked with the enamel surface. The
formation of resin micro tags within the enamel surface is the
fundamental mechanism of adhesion of resin to enamel.
158. D. Carious exposure
159. D. Co –Cr alloy
160. B. Barium and strontium glassesFiller compositions often are modified with other ions to
produce desirable changes in properties.
Lithium and Aluminium make the glass easier to crush to
generate small particles.
Barium, Zinc, Boron, Zirconium, Yttrium have been used to
produce radiopacity.
161. D. None of the above
162. A. Sodium hypochlorite
163. B. Occlusally diverging mesial and distal wallsIn Class –I cavities for dental amalgam facial & lingual walls
are occlusally converging for retention and mesial & distal
walls are occlusally diverging. In Class-I cavities for direct
filling gold or gold inlays, facial & lingual walls as well as
mesial & distal walls are occlusally diverging.
164. A. Mesiobuccal
165. D. None of the above
166. A. Calciumhydroxide cementOlder calcium hydroxide liners without Barium, Lead or Zinc
(added to lend radiopacity) appear radiolucent and may
resemble recurrent or residual caries. Despite the calciumpresent, the relatively large proportion of low atomic number
material in calcium hydroxide causes its radiodensity to be
similar to a carious lesion. Composite, plastic or silicate
restorations also may simulate carious lesions. It is often
possible however, to identify and differentiate these radiolucent
materials from caries by their well-defined and smooth outline
reflecting the preparation.
167. B. Labiolingual
168. C. Silicate
169. B. 1500This cavosurface design helps seal and protects the margins. A
cavosurface enamel angle of more than 1500 is incorrect
because it results in a less defined enamel margin and if its
angle is less than 300, the marginal cast metal alloy is too thin
and weak. Conversely, if the enamel margin is 1400 or less, the
metal is too bulky and when the angle is greater than 400, it is
difficult to burnish.
170. D. Removal of the pulp tissue
171. D. irritant
172. C. AtropineThe use of drugs to control salivation is rarely indicated in
restorative dentistry and is generally limited to the
anticholinergic drug-atropine. Atropine is contraindicated in
nursing mothers and in patients with glaucoma.
173. A. Apexification with calcium hydroxide
174. B. Apical scar
175. B. Traction principleThere are two principle methods of tooth movement-
1) Rapid/immediate tooth movement: - Wedge method
Eg: Elliot separator
Wood / plastic wedges
- Traction method
Eg. Non-interfering; true separator
Ferrier double-bow separator
2) Slow/delayed tooth movement
Separating wires, Oversized temporaries,Orthodontic
appliances.
176. B. Seepage of saliva into the canal
177. C. Both a & b
178. D