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MCQs in Endodontics - Disinfection and Obturation


# Obturation of a root canal should achieve:
A. Tug back
B. Hermetic seal
C. Fluid free seal
D. All of the above

# The purpose of a root canal sealer is to:
A. seal the tubules of the dentine
B. stimulate healing in periapical region
C. prevent discoloration
D. fill the space between solid core material and pulp canal walls



# Activity of all disinfectants is:
A. reduced by organic debris or blood
B. increased with heat
C. hastened by adding 5 % oxygen
D. nullified by ethylene dioxide gas

# Mc Spadden compactor is of _________ shape.
A. Reverse blade of K-file
B. Reverse blade of H-file
C. Endosonic instrument
D. None of the above

# An apical radiolucent area present in central incisor after 4 months of RCT is due to:
A. Inadequate obturation and leakage from main canal
B. Leakage from accessory canal
C. Leakage from gingival crevice
D. Leakage from access opening

# Gutta Percha (GP) is plasticized (softened) by:
A. Alcohol
B. Eugenol
C. Chloroform
D. EDTA

# Best material for obturating a root canal of a tooth is:
A. Thermoplastic GP
B. Silver cone
C. Resorbable paste
D. GP with sealer

# The microorganism previously present in the periapical tissues following obturation:
A. persist and stimulate the formation of a granuloma
B. are eliminated by the natural defenses
C. Re-enter and re-infect the sterile canal and are removed by surgery
D. are eliminated by the medicaments used in the endodontic treatment

# The largest component of gutta percha cones is:
A. Gutta percha
B. Zinc oxide
C. Resins and waxes
D. Coloring agents

# The vertical fracture of root seen with gutta percha obturation is due to:
A. The vertical compression of warm GP points
B. Lateral condensation of GP points
C. Use of spreader
D. Injection molding technique

# Endo-sealer containing polyketone is:
A. Cavit
B. Ah 26
C. Diaket
D. Hydron

# The success of a root canal filling is best assessed by:
A. Clinical observation
B. Size of gutta percha cone used
C. radiographs
D. the diameter of root canal reamer

# High heat obturation technique refers to:
A. Thermofill technique
B. Ultrafil technique
C. Sectional filling
D. Obtura II technique

# The function of a root canal sealer is:
A. to fill the gap between the tooth and the filling
B. as an antiseptic
C. to aid in healing
D. to provide strength

# Gutta percha is radio-opaque due to presence of:
A. Zinc oxide eugenol
B. Barium sulphate
C. Potassium sulphate
D. Barium oxide

# The crown of a 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:
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 retreat 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

# Which of the following is correct regarding the use of silver points for root canal obturation ?
A. Silver corrodes in tissue fluids
B. A post canal 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

# Main cause of failure of endodontic therapy:
A. Improper biomechanical preparation
B. Improper access cavity preparation
C. Incomplete obturation
D. Over extended filling

# The main aim of obturation is:
A. Fill the canal and prevent apical percolation of fluids
B. Fill the canal and prevent discoloration of teeth
C. Fill the canal and give support to the restoration
D. All of the above

# Best method of condensation is:
A. Lateral condensation
B. Thermoplasticized
C. Vertical condensation
D. None of the above

# Which of the following can be used as a root canal filling material?
A. Cements and plastic materials
B. G.P. Points
C. Silver points
D. All of the above

# Bismuth compounds are incorporated in root canal filling materials because they are:
A. Radio-opaque
B. Germicidal
C. Radiolucent
D. Adhesive

# Most common cause of RCT failure:
A. Incomplete removal of PA cyst
B. Non obturation of accessory canals
C. Incomplete debridement with improper obturation
D. Large size of PA pathology

# In post core which of the following gutta percha technique is used?
A. Thermoplasticized
B. Vertical
C. Sectional
D. Lateral

# Disinfection of root canal is obtained with:
A. Irrigation
B. Debridement
C. Intracanal Medicament
D. All of the above

# Calcium hydroxide is advocated as an inter appointment intracanal medication because of:
A. its ability to dissolve necrotic tissue
B. its antimicrobial property
C. its ability to stimulate hard tissue formation
D. Its powerful bleaching effect

# Rejuvenation of Gutta percha can be changed from alpha to beta form at:
A. 55-59 degree F
B. 55-59 degree C
C. 20-25 degree F
D. 20-25 degree C

# The flutes of McSpadden compactor are similar to:
A. Lentulo spiral fillers
B. Engine driven reamers
C. Flutes of Hedstroem in reverse
D. K-Flex file

# Fall in alkalinity of Ca(OH)2 when used as a root canal dressing starts at:
A. 1 week
B. 2 week
C. 4 week
D. 12 week

# The primary gutta percha cone must fill the canal wall tightly in the:
A. apical third
B. middle third
C. cervical third
D. entire canal

# The periapical radiograph of RCT treated tooth shows wiggly apical seal of master cone due to:
A. Apical perforation of aster cone
B. Excess cement in apical region
C. Obstruction of master cone at apical third
D. short master cone in apical third

# An ideal result of endodontic treatent is deposition of which of the following at the apex?
A. Bone
B. Cementum
C. Dentin
D. Periodontal ligament

# All are true for root canal sealer EXCEPT:
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

# Which is not a eugenol sealer?
A. Grossman sealer
B. AH-26
C. Tubli seal
D. Wach's paste

# MTA is used for:
A. Apexification of any dentition
B. Apexification of primary tooth only
C. Apexification of Permanent tooth only
D. Apexogenesis of any dentition

# When is an application of heated injected gutta percha potentially beneficial?
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

# Addition of synthetic resins to zinc oxide eugenol cement is said to:
A. Increase the strength
B. Reduce solubility
C. Reduce film thickness
D. None of the above

# With Obtura II system which has a high temperature, gutta percha cools to:
A. 70 degree C
B. 110 degree C
C. 130 degree C
D. 160 degree C

# Thermafil is:
A. An endodontic obturator
B. An enlarging instrument
C. An instrument to remove pulp
D. Is a cold gutta percha technique

# High heat obturation technique refers to:
A. Therofil
B. Ultrafil
C. Sectional filling
D. Obtura II

# Which of the following is urethane diethacrylate (UDMA) based endosealer?
A. Endorez
B. Real seal
C. Raeko sealer
D. Tubli seal

# The advantage of silver point as obturating material is that it:
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 third of root canal
D. provides better adaptation to canal walls compared to gutta percha

# Vertical compaction of warm gutta percha technique was given by:
A. Grossman
B. Ingle
C. Schilder
D. Cohen

# Master cone is:
A. Fully snug fit with accurate working length
B. used by master of staff
C. instrument first used in taking working length
D. last file to fit loosely

# AH plus and AH 26 are:
A. Root canal cements
B. Medicated root canal paste
C. Fillers
D. Root canal filling material

# True about vertical compaction technique is:
A. Softened heat and vertical compaction in three dimensions
B. One master cone and then filling
C. Cold plugger is used to make space
D. Softened by chemical and condense with hot plugger

# Ideal quality of root canal filling material:
A. make a seal of apically and laterally placed canals
B. shrink after insertion
C. should not permit easy removal
D. all of the above

# Silver cone used as a root canal filling material is indicated in:
A. Narrow curved canals in which enlargement beyond a no. 20/25 instrument is unadvisable
B. large canals of anterior teeth
C. Surgical cases in which root resection is anticipated
D. Incomplete large or irregular canals of a young patient

# The lorothidol added in non-eugenol paste has the function of:
A. Bacteriostatic
B. Fungicide
C. Accelerator
D. Preservative

# Advocated apical seal for dowel core is:
A. 2 mm
B. 5 mm
C. 8 mm
D. 10 mm

# The term 'Tug back' is used to indicate:
A. good fit of accessory gutta percha point at the apical third
B. good fit of master gutta percha point at the apical third
C. good fit of accessory cone in the main body of the canal
D. good fit of the initial file at the apical third