OBTURATION

1. The main objective of obturation is (PGI-98)

a. Fill the canal and prevent apical percolation of

fluids

b. Fill the canal and prevent discolouration of

teeth

c. Fill the canal to give support to restoration

d. All of the above

2. Which of the following can be used as root

canal filling materials? (PGI-95)

a. Cements and plastic materials

b. G.P. Points

c. Silver points

d. All of the above

3. Most commonly followed obturation

technique

a. Lateral condensation

b. Vertical condensation

c. Thermoplastic injection technique

d. Carrier based GP

4. Mc Spadden compactor for thermo

mechanical compaction has flutes similar to

a. Reverse of H-file

b. H-file

c. K-file

d. K-flex file

5. Mc Spadden compactor is of _________

shape (AIIMS-97)

a. Reverse blade of K-file

b. Reverse blade of H-file

c. Endosonic instrument

d. None of the above

6. ‘Hermetic seal’ literally denotes

a. Fluid-impervious seal

b. Bacteria impervious seal

c. Blood-impervious seal

d. Air-impervious seal

The achievement of a “hermetic seal” is often cited

as a major goal of root canal treatment. According

to accepted dictionary definitions, the word

hermetic means sealed against the escape or entry

of air—or made airtight by fusion or sealing.

However, root canal seals are commonly evaluated

for fluid leakage—a parameter used to praise or

condemn obturation materials and techniques.

This occurs both apically and coronally. Somehow

the term hermetic has crept into endodontic

nomenclature in a manner probably quite similar

to the invention of an airtight seal. A god of

wisdom, learning and magic in ancient Egypt,

Thoth, better known as Hermes Trismegistus

(Hermes thrice greatest), is credited with this

invention.

His significant contribution to civilization allowed

the preservation of oils, spices, aromatics,

grains and other necessities in previously

porous, earthenware vessels. A simple wax seal

of the vessel walls helped to create the

“hermetic seal.” Endodontically speaking, the

term hermetic is inappropriate; instead, terms

such as fluidtight, fluid-impervious, or

bacteria-tight seals are more

contemporary.

7. Warm vertical compaction was

introduced by

a. Kuttler

b. Schilder

c. Vertucci

d. Pineda

8. Vertical compaction of warm gutta-percha

technique, was given by? (AP-2011)

a. Grossman

b. Ingle

c. Schilder

d. Cohen

9. The best time for giving permanent restoration

after obturation is

a. 1 week after obturation

b. 1 month after obturation

c. 3 months after obturation

d. Immediately after obturation in the same

appointment

10. About gutta-percha all are true, except

(AIIMS-05)

a. It contains 60-70% gutta-percha and 20%

ZnO

b. Can be sterilized by heating

c. With time they become brittle

d. It has two forms alpha and beta

11. The largest component of gutta percha

cones is (UPSC-01, TNPSC-99)

a. Gutta percha

b. Zinc oxide

c. Resins and waxes

d. Colouring agents

12. Gutta percha can be effectively sterilized

by (AIIMS-07)

a. Hot salt sterilizer

b. Autoclaving

c. Chemical solutions

d. Dry heat

13.The most practical method to disinfect

GP is with

a. NaOCl

b. H2O2

c Hot air oven

d. Glutaraldehyde

This can be done in 1 minute if the cone is

submerged in a 5% solution of Naocl.

After this the GP should be rinsed in ethyl

alcohol to remove crystallized Naocl

before obturation, such crystals impair

the obturation seal.

14. Rejuvenation of aged gutta-percha is done by

a. Immersion in hot water of 550C

b. Immersion in hot water of 550F

c. Immersion in hot water of 550C, followed by

instant cooling in cold water

d. Immersion in hot water of 550F, followed by

instant cooling in cold water

Gutta-percha becomes brittle with age, a process

hastened with warmth and delayed when

refrigerated. Sorin and Oliet described this aging

process and introduced a technique to rejuvenate

the aged brittle gutta-percha by momentary

immersion in hot tap water of 550C, followed by

instant cooling in cold tap water.

15. The advantage of silver point as obturating material is

that it (KCET-2011)

a. Can be used in fine tortuous canals

b. Is easier to retrieve if retreatment becomes necessary

c. Gives a perfect seal at the apical l/3rd of the root canal

d. Provides better adaptation to canal walls compared to

Guttapercha

16. Which one of the following is not a popular

method of root canal obturation (TNPSC

2006)

a Lateral condensation

b. Silver point technique

c. Vertical condensation

d. Thermo-plasticized core filler technique

With the introduction of rigid silver cones it became

possible to easily place them to length. This

resulted in clinicians often failing to properly

clean and shape the canal before obturation.

Treatment failures were the result of leakage and

failure to remove the irritants from the root canal

system. When silver points contact tissue fluids or

saliva, they corrode.

The corrosion products have been found to

be cytotoxic and produced pathosis or

impeded periapical healing.The use of

silver cones today is considered to be

below the standard of care in

contemporary endodontic practice.

17. Which of the following Is Incorrect

regarding the use of silver points for root

canal obturation (AIIMS-2K, 01)

a. Silver corrodes in tissue fluids

b. A post cannot be used if a silver point is

cemented in root canal

c. The use of step back method of root canal

preparation in a circular configuration is

difficult to achieve in the apical segment

with silver point

d. It will not seal the middle and cervical

parts

Split Cone Technique

A variation of the silver cone technique was

employed where a post was needed to support

a coronal restoration. This variation had been

presented under many names, but it was

usually recognized as the split cone technique.

The silver cone was fitted carefully.

Before cementation, however, the cone was scored

deeply with a disk or bur at some distance from

its apical end. Cementation proceeded, but after

the cone had been seated well, its coronal end was

rotated repeatedly along its long axis. While

rotating, firm apical pressure was applied

through the pliers to prevent unseating at the root

apex.

As the rotary motion continued, the cone

would be severed at the score line and all

but the apical portion was removed. The

middle and coronal parts of the canal

were available for a post.

18. Which of the following best describes the resistance form in

endodontic root canal preparation? (AIIMS-06)

a. The establishment of apical tug back resistance to prevent the

apical root fracture during obturation

b. The cavity form which is obtained for application of condenser in

vertical compaction

c. The cavity form which is obtained for application of condenser in

lateral compaction

d. Cavity form which is designed to obtain for entry of condenser

during obturation

19. Lentulo spirals are endodontic

instruments used for (TNPSC 2006)

a. Exploration

b. Debridement

c. Cleaning and shaping

d. Obturation

20. The primary gutta-percha cone must fill the

canal wall tightly in the: (COMED-05, AP-05)

a. Apical third

b. Middle third

c. Cervical third

d. Entire canal

21. The technique of obturation for open

apex

a. Warm vertical condensation

b. Thermoplastisized injection technique

c. Lateral condensation

d. Roll cone technique

22. J. S. Quickfill is (COMDEK-08)

a. The original engine driven McSpadden's

compactor with guttapercha already coated

b. Like thermafill another obturator

c. No different than original Mcspadden's

compactor

d. Chemically softened gutta-percha

J.S. Quick-Fill system consists of titanium core

devices that come in ISO sizes 15 to 60, resemble

latch-type endodontic drills, coated with alpha-

phase gutta-percha. These devices are fitted to

the prepared root canal and then, following the

sealer placement, are spun in the canal with a

regular low-speed, latch-type handpiece.

Frictional heat plasticize the gutta-percha and it is

compacted to place by the design of the Quick-Fill

core. After compaction, there are two choices:

either the compactor may be removed while it is

spinning and final compaction completed with a

hand plugger or the titanium solid core may be

left in place and separated in the coronal cavity

with an inverted cone bur.

23. In Endodontics Endotec is used (COMEDK-

08)

a. With lateral condensation and heated gutta

percha

b. With cold lateral compaction

c. With vertical compaction

d. With Chlorapercha Technique

Considering the ease and speed of lateral

compaction as well as the superior density gained

by vertical compaction of warm gutta-percha,

Martin developed a device that appears to

achieve the best qualities of both techniques called

Endotec II. The device is a battery powered, heat-

controlled spreader/plugger that ensures complete

thermo-softening of any type of gutta-percha.

It is claimed that the “Endotec combines the best of the

two most popular obturation techniques:

warm/vertical and the relative simplicity of lateral

compaction”. Canal cleaning and shaping for this

technique is a continuous taper design with a definite

apical stop. The warm lateral compaction technique

involves adapting a master cone in the same manner

as with traditional lateral compaction.

An appropriate-size Endotec II tip is selected. Endotec

II tips are available in various taper and tip

diameters. The sizes consist of #.02/20 ,30 and #.02/40.

The device is activated and the tip is inserted beside

the master cone to within 2 to 4 mm of the apex, using

light pressure. The tip is rotated for 5 to 8 seconds

and removed. An unheated spreader can be placed in

the channel created to ensure

adaptation and then an accessory cone is

placed. The process is continued until the

canal is filled.

24. High heat obturation technique refers to

(KAR-02)

a. Thermofill technique

b. Ultrafil technique

c. Sectional filling

d. Obtura II technique

25. Thermafil is (COMEDK-08)

a. An endodontic obturator

b. An enlarging instrument

c. An instrument to remove pulp

d. Is a cold gutta percha technique

26. Wiggly appearance of master cone in the

apical third of IOPA is due to (AIPG-07)

a. Extrusion of sealents.

b. Master cone not reaching the apical third due

to any obstruction.

c. Smaller sized master cone.

d. Inadequate coating of sealent.

If the cone goes to length and

radiographically exhibits a wiggly or S-

shaped appearance, the cone is too small

for the canal and a larger cone must be

selected.

27. When is an application of heated Injected gutta

percha potentially beneficial (COMDEK-08)

a. When there is an open apex

b. When there are aberrations or irregularities of the

canal

c. When the clinician cannot master lateral condensation

d. When the canals are curved and small after

preparation

28. Best material for obturating a root canal

of a tooth is (PGI-2K)

a. Thermoplastic GP

b. Silver cone

c. Resobable paste

d. GP with sealer

29. G.P. is plasticized (softened) by (AP-01)

a. Alcohol

b. Choroform

c. Eugenol

d. EDTA

30. Bismuth compounds are incorporated in root

canal filling materials because they are:

(AIPG-89)

a. Radio-opaque

b. Germicidal

c. Radiolucent

d. Adhesive

31. Gutta-percha is radio-opaque due to

presence of: (AIPG-99)

a. Zinc oxide eugenol

b. Barium sulphate

c. Potassium sulphate

d. Barium oxide

Heavy metal sulphates are added as radio-

opacifier to GP.

32. Main cause of failure of endodontic

therapy: (PGI-98, 02 ; AP-04)

a. Improper biomechanical preparation

b. Improper access cavity preparation

c. Incomplete obturation

d. Over extended filing

33. An apical radiolucent are present in central

incisor after 4 months of RCT is due to: (AIIMS-

97)

a. Inadequate obturation & leakage from main canal

b. Leakage from accessory canal

c. Leakage from gingival crevice

d. Leakage from access opening

34. The purpose of a root canal sealer is to

(AIPG 99, PGI 99)

a. Seal the tubules of the dentin

b. Stimulate healing in periapical region

c. Prevent discolouration

d. Fill the space between the solid core material

and the pulp canal walls

Root canal sealers are necessary to seal the

space between the dentinal wall and the

obturating core interface.

35. Endo sealer containing polyketone is

(AP-2K, 03)

a. Diaket

b. Cavit

c. Ah 26

d. Hydron

36. Which is not a eugenol sealer? (AIPG-

07)

a. Grossman sealer

b. AH-26

c. Tubli seal

d. Wach's paste

Kerr Pulp Canal Sealer, Pulp Canal Sealer EWT

(Extended Working Time), Procosol, Roth’s

Sealer, Tubliseal, Wach’s Cement are various

Zinc-oxide eugenol sealers. Nogenol was

developed to overcome the irritating quality of

eugenol. The product is an outgrowth of a non-

eugenol periodontal pack. AH-26 is a epoxy resin

based root canal sealer.

37. Which of the following is urethane

dimethacrylate (UDMA) resin based

endosealer? (AIIMS-09)

a. Endorez

b. Real seal

c. Raeko sealer

d. Tubli seal

38. All are true for root canal sealer except: (AIPG-07)

a. Excessive use of sealer tends to extrusion in periapical

areas

b. Sealer mediates immune reaction in periapical region

c. Loss of sealer causes porosity between root filter and

tooth surfaces

d. Sealer occupies the space between root filler and tooth

surfaces

39. After root canal filling the apical

foramen is closed by: (AIPG-07)

a. Dentin deposition

b. Cementum deposition

c. Never closed

d. Root canal material

40. The crown of an RC treated tooth is fractured

near the gingival margin. The coronal end of the

silver cone used in filling that canal is visible at that

level. Treatment is: (AIPG-02)

a. To prepare post space alongside the silver cone

using burs and Peso reamers

b. To grind away the coronal part of silver cone using

round burs or end cutting burs

c. To remove the silver cone and re-treat the

canal using a gutta-percha; and then to

create the needed post space

d. To remove the silver cone, notch it, coat it

with a freshly mixed sealer replace it in the

canal and twist off the coronal segment