MCQs in Endodontics - Biomechanical Preparation

# The root canal instrument most likely to break during use is a:
A. File
B. Broach
C. Reamers
D. Spreaders

# While root canal biomechanical preparation apical constriction is enlarged to 50 sized instrument. You would like to:
A. Use reverse filling technique
B. Reinstrument with larger instrument 1 mm short of previous preparation
C. Fit a 50 mm cone and condense carefully
D. Fill with 40 sized cone

# The first instrument to extirpate pulp is:
A. Barbed broach
B. K-type file
C. Reamer
D. H-type file

# The ideal instrument that is used to widen the canal is:
A. Broach
B. File
C. Fissure bur
D. Reamer

# The most effective means of reducing microbes in root canal:
A. Frequent medication of root canal
B. Complete debridement through instrumentation
C. Systemic antibiotics
D. All of the above

# A giromatic hand piece for endodontic instrumentation operates by a:
A. Rotating motion
B. Oscillating motion
C. Zig-Zag motion
D. All of the above

# File is manufactured from a:
A. Triangular blank
B. Round blank
C. Square blank
D. Diamond shaped blank

# The difference between a reamer and a file is in:
A. The number of flutes
B. The number of flutes and shape of the shaft
C. The number of flutes and the size of the shaft
D. The shape and size of the shaft

# An endodontic reamer is least likely to fracture when inserted in a:
A. Dry, clean canal
B. Wet, clean canal
C. Wet, debris laden canal
D. Dry, debris laden canal

# To prevent the fracture of an endodontic instrument the number of turns given inside the canal in a single motion should be:
A. Less than 1/4 of a turn
B. 1/4 to 1/2 turn
C. 1/2 of a turn
D. More than 3/4

# First instrument inserted into the root canal through the access cavity is:
A. Barbed broach
B. H file
C. K file
D. Any of the above

# Difference between physical characteristic of reamers and files is:
A. The cross-section of reamers in square and files are triangular in cross-section
B. The number of flutes on the blade are more in files than in reamers
C. The reamers have more flutes in the blade
D. Files have two superficial grooves to produce flutes in a double helix design

# Gates-Glidden drill is:
A. Flexible and used at Low speed
B. Flexible and used at high speed
C. Inflexible and used at low speed
D. Inflexible and used at high speed

# Which of the following is a disinfectant, sterilizing agent and an antiseptic?
A. Sodium hypochlorite
B. Glutaraldehyde
C. Hydrogen peroxide
D. Methylated spirit

# Power driven instrument is:
A. Gates glidden drill
B. Reamers
C. Giromatic
D. Racer-Engine

# Endosonics utilizes which instrument?
A. H file
B. K file
C. Endo box
D. Reamers

# The best instrument for cutting dentin is:
A. Reamer
B. File
C. Broach
D. Explorer

# The instrument most likely to push debris through the apex is:
A. Reamer
B. File
C. Broach
D. Smooth explorer

# D2 on the endodontic file indicates:
A. Diameter at tip of instrument
B. Angle of instrument
C. Length of instrument
D. 1/1OOth mm at end of cutting blade

# Working length of root canal is:
A. 0.5 to 1 mm short of radiographic apex
B. 1 to 2 mm short of apex
C. Exactly at apex
D. 1 to 2 mm apical to apex

# Gross debridement, lubrication, microbial destruction and tissue dissolution are done by this irrigating solution:
A. Sodium hypochlorite
B. Normal saline
C. RC prep
D. Hydrogen peroxide

# Reamers and files differ mainly in:
A. Cross sectional form
B. Colour coding
C. Number of flutes along the blade
D. Instrument formula

# Instrumentation well short of the apical foramen can result in:
A. Forcing necrotic material into the periapical region
B. Shelfing or ledging the canal
C. Traumatizing the periapical tissues
D. Grossly enlarging the apical foramen

# The safest instrument for removing the pulp from the very fine canal is:
A. Barbed broach
B. Small K type file
C. Tempered universal Headstroem file
D. Smooth broach

# Reaming action of the reamer is:
A. Pushing regenerating
B. Pushing, rotating & regenerating
C. Pushing & pulling
D. None

# Which of the following is correct about root canal preparation?
A. Retention form is provided by 2 mm of near parallel walls at the end of root preparation (apical 2/3 rd) to provide tug back of master cone
B. Resistance form is provided by parallel walls of apical seat to preserve the integrity of natural constriction (apical matrix)
C. Extension form - all instrumentation should terminate 0.5 mm of short of radiographic apex
D. All of the above are correct

# _____________ is helpful in making radicular access:
A. Gates glidden drill
B. K-File
C. K-reamer
D. Round bur

# Recapitulation:
A. Uses large files to flare the root canal
B. Removing debris with a smaller instrument than the instrument that goes to the apex
C. Use of larger files to flare the root canal but in between use of small instruments to confirm the initial length
D. The use of various types of reamers and files to enlarge the root canal

# When pulp cannot be extirpated in narrow canals, which of the following can be used:
A. Obtundant
B. Astringent
C. Haemostatic
D. Mummifying agent

# Root canal is flooded with antiseptic so as to:
A. Prevent the removal of the shavings from the root canal
B. Where there is an absence of instrumentation
C. Prevent infection during instrumentation
D. Avoid instrumentation

# Purple coloured reamer is numbered:
A. 08
B. 10
C. 15
D. 30

# During root canal instrumentation, the apical constriction is violated and enlarged to a size no. 50 instrument, which of the following is appropriate treatment for this canal:
A. Obturate with gutta-percha and surgically remove extruded excess
B. Fit a No. 50 gutta-percha cone with sealer and carefully condense
C. Fit a No. 50 gutta-percha cone with sealer but don't condense so as to keep the G. P. from being pushed into the foramen
D. Reinstrument 1 mm short of the fora men to a size No.60 or larger and obdurate using an appropriately sized master cone

# Barbed broach is used for:
A. Extirpation of pulp
B. Enlargement of canal
C. Obturation of canals
D. All of the above

# EDTA, which is an active ingredient in root canal preparation, has its principal action in:
A. Decalcification of dentine
B. Dissolution of necrotic debris
C. Lubrication of the canal during instrumentation
D. All of the above are correct

# Hypochlorite does not cause:
A. Bleaching
B. Remove smear layer
C. Lubricating
D. Flush out debris

# Angle of Tip of an endodontic instrument
A. 75+15
B. 75-15
C. 75 +/- 15
D. 80

# Smallest number file is:
A. 4
B. 6
C. 8
D. 10

# Sequence of endodontic instrumentation:
A. Broach-reamer-file
B. Reamer-Broach-file
C. File-Reamer-Broach
D. File-broach-reamer

# Most important step in root canal preparation:
A. Biomechanical preparation
B. Obturation
C. Access canal opening
D. None of the above

# Most important criteria in using irrigating solution is:
A. Volume of irrigation
B. Thickness of syringe used
C. Concentration of irrigant
D. None of above

# In endodontic practice, periapical radiographs are very useful in assessing the:
A. Length of the root canal
B. Presence of infection in the pulp
C. Vitality of the pulp
D. All of the above

# The most common error seen during access cavity preparation of maxillary and mandibular incisors is:
A. Perforation of the lingual or labial walls
B. Gouging of pulpal contents
C. Tooth fracture
D. All of the above

# RC-prep is a combination of?
A. EDTA with carbamide peroxide
B. EDTA with hydrogen peroxide
C. EDTA with sodium hypochlorite
D. EDTA with urea peroxide

# Resistance form of endodontics is:
A. Resists movement of gutta-percha in apical area
B. To allow use of spreader in lateral condensation
C. Fracture of root while vertical condensation
D. None of the above

# Peeso reamer is used for:
A. To remove lingual shoulder of anterior teeth
B. To enlarge root canal orifices
C. Post space preparation
D. To remove gutta percha

# Lentulospirals are used for:
A. Locating canal orifice
B. Pulp extirpation
C. Enlarging coronal third root canal
D. Application of root canal sealer

# Following movement of tip is seen in Giromatic hand piece:
A. Reciprocating 90 degree arc
B. 180 degree arc
C. Oscillating to and fro moments
D. Vertical displacement of tip

# The primary function of access openings is to:
A. Facilitate canal medication
B. Provide good access for irrigation
C. Aid in locating canal orifices
D. Provide straight line access to the apex

# The Massermann Kit technique for removing solid objects:
A. is very short procedure
B. is more successful in posterior teeth than in anterior ones
C. requires frequent radiographic monitoring
D. is better than the ultrasonic technique

# About gutta-percha all are true, except:
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

# H-file is used to:
A. Locate the canal orifice
B. Flare the root canal
C. For irrigation of root canal
D. All of the above

# Gutta Percha can effectively be sterilized by:
A. Hot salt sterilizer
B. Chemical solutions
C. Autoclaving
D. Dry heat

# The Last solution used in root canal treatment to avoid painful surgical emphysema before dressing is:
A. Normal saline
B. EDTA
C. Hydrogen peroxide
D. Sodium hypochlorite

# Location of root canals is best done by endodontic:
A. Probe
B. Explorer
C. Ultrasonic system
D. File

# A 15% solution of EDTA has a pH of:
A. 5.5
B. 7.3
C. 7.9
D. 7

# According to ISO standardization, root canal files and reamers should have a taper of:
A. 0.02 mm per cm
B. 0.02 mm per mm
C. 0.03 mm per cm
D. 0.03 mm per mm

# K-flex file is traditionally made from:
A. Rhomboidal
B. Circular
C. Spiral
D. Double helix

# All of the following are true regarding removal of dentin smear layer during root canal preparation except:
A. Removal of dentin smear layer is done by using 37% EDTA
B. Dentin smear layer contains debris and microoroganism
C. Removal of dentin smear layer removes microorganism
D. Removal of dentin smear layer is enhanced by EDTA

# Recently used irrigation solution is:
A. MTAB
B. MTAC
C. MTAD
D. MTAE

# Best method to sterilize absorbent points is:
A. Autoclaving
B. Chemical sterilizer
C. Glass bead /salt sterilizer
D. Passing in ethanol flame

# Two pulp canals are usually found in:
A. Mesial root of permanent mandibular first molar
B. Distal root of permanent mandibular first molar
C. Palatal root of permanent maxillary first molar
D. Distal root of permanent mandibular second molar

# Rat tail file is also known as:
A. Barbed broach
B. R file
C. H file
D. Rasp

# The root canal instrument most Likely to break during instrumentation is:
A. H-file
B. K-file
C. Reamer
D. Pathfinder

# In Endodontics Endotec is used:
A. with Lateral condensation and heated gutta percha
B. with cold lateral compaction
C. with vertical compaction
D. with Chloro Percha Technique

# Step down technique is:
A. Preparation from apical to middle third
B. Preparation from apical to coronal third
C. Preparation from coronal to middle third
D. Preparation from coronal to apical third

# Hedstroem file is an instrument used for:
A. Canal enlargement
B. Length determination
C. Obturating with gutta percha in Mcspadden technique
D. Endodontic implants

# Ni-Ti instruments are flexible because of their:
A. Plasticity
B. Rigidity
C. Superelastcity
D. Hardness

# Instrument having Shank with alternating cutting edges:
A. Real world endo
B. Endotech endo. instrument
C. RACE
D. K-6

# All of the following may result in under filling of a root canal EXCEPT:
A. Apical perforation
B. Edge formation
C. Short length estimation
D. Lateral perforation

# Electronic apex locator is used in Endodontics to determine the:
A. Root canal morphology
B. Working length
C. Pulp stone Location
D. Pulp vitality

# The most suitable instrument to remove gutta percha from the root canal is:
A. barbed broach
B. peeso reamer
C. tapering fissure bur
D. round bur

# In Ingle's method of Endodontic working length determination, safety allowance is for:
A. Possible image distortion or magnification
B. To confirm with apical termination
C. Periapical bone resorption
D. Recording final working length

# The potentially hazardous irrigant causing an emergency during treatment is:
A. Saliva
B. Chlorhexidine
C. Sodium Hypochlorite
D. Metrogyl

# In an endodontic file, D2 will be:
A. At the tip of the instrument
B. At 2mm from the tip of the instrument
C. At 3mm from the tip of the instrument
D. At 16mm from the tip of the instrument

# The file which has a non-cutting side is:
A. K-files
B. Safety K-files
C. Hedstrom files
D. Safety Hedstrom files

# Most root canals that have not been instrumented are too narrow to be reached effectively by:
A. Microbes
B. Disinfectants
C. Gutta percha
D. None of the above

# Ultrasonic devices are instruments for the removal of dentin from root canal walls have proved to be:
A. Effective
B. Disappointing
C. Lethal
D. None of the above

# H type endodontic instrument has a spiral edge arranged to allow cutting during:
A. Pushing stroke
B. Pulling stroke
C. Circular stroke
D. Oblong stroke

# Ultrasonic devices operate at:
A. 25-30 KHz
B. 35-40 KHz
C. 2-3 KHz
D. 5-10 KHz

# When it is made up of same steel, size 55, which will be more prone to fracture?
A. Triangular reamer
B. Rhomboid cross section file
C. Square cross section file
D. Hedstroem file

# In K-file the most common type of motion is:
A. Watch winding
B. Linear
C. Rotating through 90° arch
D. Linear & clockwise

# File commonly used for flaring of the canal & retreatment:
A. H-file
B. K-file
C. K-flex file
D. Lentulospiral

# In order to complete a cutting circle of canal wall, the triangular shaft instrument requires:
A. One-fourth turn
B. One-third turn
C. One-half turn
D. One full turn

# The significance of free eugenol in root canal sealer cements is an increase in:
A. Dimensional stability
B. Setting time
C. Cytotoxicity
D. Strength

# The objectives of cleaning and shaping are all the following EXCEPT:
A. To debride the root canal
B. To shape/contour the root canal walls
C. To aid condensation of an inert filling material
D. Should keep the apical foramen as small as practical

# The commonly used root canal irrigant, which was used for irrigation wounds during world war 1 by Dakin is:
A. Saline
B. Hydrogen peroxide
C. Buffered sodium hypochlorite
D. Distilled water

# Cleaning of files in between of endodontic treatment is done by:
A. Gauze soaked in hypochlorite solution
B. 15 seconds in glass bead sterilizer
C. 30 seconds in glass bead sterilizer
D. Chlorhexidine

# In root canal treatment, the canal orifices are located by:
A. Endodontic excavator
B. DG-16 Endodontic explorer
C. C+ file
D. H-file

#The number on the handle of a root canal instrument denotes:
A. Length of the instrument in 1/10 of a millimetre
B. Length of the instrument in millimetres
C. Diameter at the tip in 1/100 of a millimetre
D. Diameter at the tip in 1/10 of a millimeter

# File with R phase technology:
A. Protaper
B. Wave one
C. Twisted
D. Race

# When root canal instruments (files and reamers) are sterilized in a glassbead sterilizer at 450 degree F., they should be placed in the sterilizer for:
A. 2 seconds
B. 5 seconds
C. 10 seconds
D. 20 seconds

# The primary principle of treating endodontic periapical lesions is:
A. To eradicate irritants in the root canal system
B. To reduce the inflammation in the periapex
C. To maintain the health of the periodontium
D. To relieve the symptoms

# Instrument used for lateral condensation of gutta percha along the canal wall:
A. Barbed broach
B. Plugger
C. Reamer
D. Spreader

# Instruments used for removal of lingual shoulder and enlarge orifices of a root canal are:
A. Gates Glidden drills
B. Peeso reamers
C. Compactor
D. H File

# All of the following are true about H-files EXCEPT:
A. They have good cutting efficiency
B. They are fragile and tend to break easily
C. They are used in torquing action
D. They have more positive rake angle

# Which of the following is not a function sodium hypochlorite?
A. Organic tissue solvent
B. Bleaching
C. Antibacterial
D. Inorganic tissue solvent

# Advantage of NiTi over K-files:
A. Increased flexibility
B. Low resiliency
C. Resistance to breakage
D. Less expensive

# The superelastic property of the NiTi wire is due to:
A. Stress induced phase transition from the austenitic to the martensitic phase
B. Temperature induced phase transition from the martensitic to the austenitic phase
C. Stress induced phase transition from the martensitic to the austenitic phase
D. Temperature induced phase transition from the austenitic to the martensitic phase

# In case of retreatment which is ideal for removal of Gutta percha?
A. H-file
B. K-file
C. GT-file
D. Lentulospiral

# All the following are the objectives of access cavity preparation EXCEPT:
A. To remove all caries
B. To completely unroof the pulp chamber
C. To achieve straight line access to apical foramen
D. To have converging axial walls for preservation of tooth structure

# The shape of head of a Gates Glidden drill is:
A. Flame shaped
B. Cone shaped
C. Ball shaped
D. Diamond shaped

# Anderson and Hillman in 1971 introduced this into orthodontics:
A. Beta NiTi
B. NiTinol
C. Chinese NiTi
D. Sentalloy

# Schielder principle is:
A. Minimal enlarged apical foramen
B. Shape of the canal can be changed
C. Use of 3-5 times larger than first binding file
D. Original canal curvature should be altered to make it compatible with obturating material