2. Pag 350. #8
The level of streptococcus mutans has been shown to be significantly higher in the
bacterial plaque adjacent to which type of posterior restoration?
A. Glass-ionomer.
B. Composite resin. significantly higher growth of streptococcus mutans group in
Class II resin composite restorations and lactobacillus in amalgam restorations
C. Amalgam.
D. Gold castings
Clinical Apsect Dental material. Composite Resine (pag 399)

3. Pag355 # 7
Which statement is true with respect to Class II composite resin
preparations?
A. Extension for prevention is a key element.
B. Fissures are only included when carious.
C. Including occlusal grooves makes the restoration more fracture-
resistant compared to a slot preparation.
D. The preparation has a ―standard‖ shape for each individual
tooth
unlike conventional amalgam tooth preparations, the
conventional tooth preparation for composite does not
usually incorporate secondary retention features; does
not require 90-degree composite margins, is usually
more conservative in extensions; and is left with roughened,
rather than smooth, preparation walls.
Ref Art and science of operative dentistry Pg 551

4. Pag357 # 2
The most accurate indicator of caries activity in root caries
lesions is to
A. assess the colour.
B. evaluate the hardness
C. use bitewing radiographs.
D. apply caries detector dyes
Textbook of Operative Dentistry
edited by Nisha Garg, Amit Garg Pag 85

5. Pag357 # 3
An incipient lesion on an interproximal surface is usually located
A. at the contact area.
B. facial to the contact area.
C. lingual to the contact area.
D. gingival to the contact area.
E. occlusal to the contact area.
MCQs in Community Dentistry 2006
By Saravanan Pag 77

6. Pag358 # 5
Which of the following will result from a 2 week regimen of tooth whitening using a
10% carbamide peroxide gel in a custom tray for 8 hours each night?
A. Moderate demineralization of enamel.
B. Significant incidence of irreversible pulpitis.
C. Decreased bonding potential to enamel.
D. Decreased enamel surface porosity
It is evident from the literature that factors such as pH, acid concentration,
temperature, exposure time and frequency of exposure can all contribute to enamel
erosion and demineralization and may affect restorations as the patient attempts to
whiten his or her teeth. Further research is needed to study the effects of these factors
and to explore how the adverse effects of a low-pH tooth-whitening product could be
minimized (e.g., by adding small amounts of calcium to the product).
J Can Dent Assoc 2000; 66:421-6
Immediately after the bleaching procedure, the surface porosity of enamel had
increased (J Esthet Restor Dent. 2002;14(4):238-44.Effects of 10% carbamide peroxide
on the enamel surface morphology: a scanning electron microscopy study.)

7. Pag360 # 1
A 10-15 second application of 37% phosphoric acid on prepared dentin will result in
all of the following EXCEPT
A. elimination of the smear layer
B. opening of the dentinal tubules.
C. demineralization of the superficial dentin.
D. elimination of the collagen fibres
1. the uncovering of a large number of dentinal tubules
that had been covered by the smear layer (p<0,05);
2. dentinal tubule diameter to increase (p<0,05);.
3. dentinal tubule surface percentage increase over the
entire exposed dentinal surface (p<0,001);
4. intertubular dentin surface percentage decrease over
all exposed dentinal surface (p<0,001);
5. appearance of the dentin surface porous zone containing
smear layer and demineralized residual collagen
particles with dentin demineralization products in
acid globules (p<0,001); and
6. complete dissolving of peritubular dentin cuff (p<
0,001).
Influence of Different Etching Times on Dentin Surface Morphology
etching of dentin and rinsing removes the smear layer, leaving a
smooth surface with patent tubules. Demineralization of the dentin surface
and subsurface is known as the total etch technique;( Dental Materials at Glance Pg 71)

8. Pag360 # 8
A Class II amalgam preparation on a primary tooth does NOT require a gingival bevel
because the enamel rods in the area incline
A. gingivally.
B. horizontally.
C. occlusally.
D. vertically
Class 2 cavity preparation - Primary molars
• Complete class 1 using #330 bur
• Extend occlusal outline to marginal ridge
• Switch to #245 Bur - 3 mm length
• Sweep bur buccolingually in a pendulum motion
and in a gingival direction.
• Break contacts and check with explorer
• Axial wall should follow external contour
• Width of isthmus 1/2 of occlusal table
• Proximal box widest at gingival margin
• Rounded axiopulpal line angle
• No bevel at the gingival margins

9. Pag361 # 5
Which is the most appropriate method to minimize loss of dental amalgam and
mercury from dental offices into sewage systems?
A. Use of ISO approved amalgam separators.
B. Storage of amalgam capsules in sealed containers.
C. Use of mercury vapour scavengers.
D. Disposal of scrap amalgam in a landfill site.
What is an ISO 11143 Certified Amalgam Separator?
An ISO 11143 Certified Amalgam Separator is a device which enables dental clinics
to capture pieces of amalgam from new amalgam fillings or amalgam extractions,
so that these tiny pieces of amalgam – which contain mercury - are prevented from
being flushed back into municipal water systems where they can contaminate the
environment.
The unit is attached to a compressor unit which controls the suction and water flow
for a dental clinic. The units will fill up with amalgam waste over a period of time
and need to be periodically changed.
Note: Environment Canada has published the FINAL NOTICE requiring every
Canadian Dentist to have an ISO 11143 Certified Amalgam Separator and
Recycling Program in place.

10. Pag361 # 7
What is the name of the process by which carbamide peroxide bleaches the teeth?
A. Oxidation.
B. Addition.
C. Subtraction.
D. Hydrogenation.
Carbamide
peroxide, a weaker oxidizing agent, breaks down into hydrogen
peroxide and urea.
Clinical aspects dental material Pg 226

11. Pg363#4
Compared to heat cured acrylic resins, cold cure acrylic resins are
A. stronger and more colour stable.
B. weaker and more colour stable.
C. weaker and less colour stable.
D. stronger and less colour stable
Products that are properly heat-cured are a bit stronger and
tougher than cold-cure acrylic resins
Clinical Aspect dental Material Pag 155

12. Pag367 # 1
The earliest colonizers of dental plaque are
A. Gram-positive rods.
B. Gram-positive cocci
C. Gram-negative rods.
D. Gram-negative cocci
The first event in the development of caries is the deposit of plaque on the teeth.
Dental plaque is a highly organized gelatinous mass of bacteria that adheres to the
tooth surface. Streptococcus mutans produce great amounts of lactic acid
Streptococcus mutans and Lactobacilli are the most common cariogenic
bacteria in coronal caries.
■ Actinomyces viscus (gram posotive) is the most common cariogenic bacteria in root
surface
or smooth surface caries.
■ Dental plaque organisms—Streptococcus sanguis found earliest
■ Other offenders: Actinomyces naeslundi, Veillonella, Streptococcus salivarious

13. Pag366 # 7
Which of the following is the most reliable indication of an active root caries lesion?
A. Brown discolouration.
B. Abfraction deeper than 1.5mm.
C. Discoloured lesion with the same hardness as healthy root surface.
D. Soft or leathery consistency.
Textbook of Operative Dentistry
edited by Nisha Garg, Amit Garg Pag 85

14. Pag366 # 8
What is the most likely cause of food impaction at the site of a recently placed
Class II composite resin restoration?
A. Inadequate proximal contact
B. Gingival overhang
C. Inadequate marginal ridge morphology.
D. Poor oral hygiene
Ideal contacts serve by
Maintaining the dental arch stability by transmitting forces along the long axis of
teeth, Protecting the interdental papilla by preventing food impaction and,
Influencing speech and cosmetics, especially in the anterior region.[
Conserv Dent. 2011 Oct-Dec; 14(4): 330–336
Optimizing tooth form with direct posterior composite
restorations

15. 368 pag 6
Which is the most appropriate treatment for a patient who reports persistent thermal
sensitivity 4 weeks after placement of a posterior composite resin restoration with
acceptable occlusion?
A. Adjust the restoration slightly out of occlusion.
B. Replace the restoration with a reinforced zinc oxide eugenol restoration.
C. Replace the restoration with a bonded amalgam restoration.
D. Replace the restoration with a bonded composite resin restoration.
The American Dental Association 2 (ADA) has indicated the appropriateness of composites for use as pit and-
fissure sealants, preventive resins, initial Classes I and II lesions using modified conservative tooth preparations,
moderate-sized Classes I and II restorations, Class V restorations, restorations of esthetically important
areas, and restorations in patients allergic or sensitive to metals. The ADA does not support the use of
composites in teeth with heavy occlusal stress, sites that cannot be isolated, or patients who are allergic or sensitive
to composite materials. If composites are used as
indicated, the ADA further states that "when used correctly
in the primary and permanent dentition, the expected
lifetime of resin-based composites can be comparable to
that of amalgam in Class I, Class II, and Class V restorations.“(Operative dentistry 2000)
Bonded amalgams have "bonding" benefits:
• Less microleakage
• Less interfacial staining
• Slightly increased strength of remaining tooth Structure
• Minimal postoperative sensitivity
• Some retention benefits
• Esthetic benefit of sealing by not permitting the amalgam to discolor the adjacent tooth structure

16. 368 pag 7
During matrix band removal, the risk of marginal ridge fracture of an amalgam
restoration is reduced by
A. completing most of the shaping of the marginal ridge before removal.
B. leaving an excess of amalgam in the occlusal area before removal.
C. contouring and wedging the band.
D. using universal circumferential retainers and bands
MARGINAL RIDGE FRACTURES
Causes of marginal ridge fractures
• Axiopulpal line angle not rounded in Class II tooth
• preparations
• Marginal ridge left too high
• Occlusal embrasure form incorrect
• Improper removal of matrix
• Overzealous carving
Operative dentistry 2000 pag 667

17. Pag 368 # 8
Bevelling the enamel at the gingival cavosurface margin of a Class II cavity
preparation for amalgam is
A. contraindicated because of the weak edge of amalgam.
B. provided by a steep cavosurface bevel of the enamel margin.
C. unnecessary since the remaining tooth structure is strong.
D. needed to remove unsupported enamel rods
Operative dentistry 2000 pag 667

18. 369#1
Which is the best initial treatment for a 16 year old patient presenting with
multiple extensive carious lesions on 20 teeth?
A. Place amalgam restorations as quickly as possible.
B. Excavate and place provisional restorations.
C. Place the patient on a preventive regime and delay any treatment.
D. Restore all teeth with gold inlays to utilize the strength of the material
Operative dentistry 2000 pag 126

19. 369#2
A dry and crumbly mix of amalgam can be the result of
A. under trituration
B. over trituration
C. high copper content
D. lack of zinc content
Under-triturated amalgam has a mushy grainy feel because not all of the particles
are broken up.
The process of mixing the alloy with mercury in the amalgamator.
■ Undertriturated = dull, crumbly, ↓strength, ↑creep.
■ Overtriturated = wet, runny, sticky, ↓↓strength, ↑corrosion, ↓setting expansion
time, ↑creep.
■ Properly triturated = shiny, smooth, and homogenous.

20. 369#8
A 2½ year old lives in a community with 0.5ppm fluoride in the drinking water.
What is the most appropriate preventive management?
A. Regular recall appointments.
B. Fluoride varnish at 3 month intervals.
C. Daily fluoride drops.
D. Fissure sealants on the second primary molars.(23 months of age complete
primary teeth eruption)
2 - 6 Years
1. Repeat 12- to 24-month procedures every 6 months or
as indicated by the individual patient's needs/susceptibility
to disease. Provide age-appropriate oral
hygiene instructions.
2. Complete a radiographic assessment of pathology
and/or abnormal growth and development, as indicated
by the individual patient's needs.
3. Scale and clean the teeth every 6 months or as indicated
by the individual patient's needs.
4. Provide topical fluoride treatments every 6 months or
as indicated by the individual patient's needs.
5. Provide pit and fissure sealants for primary and permanent
teeth as indicated by the individual patient's
needs.
Dentistry for the Child and Adolescent by Mcdonald Pag 4
.

21. 372#1
A 10 year old child with no previous caries experience has proximal carious lesions
in the enamel only of several primary molars. How should the lesions be managed?
A. No treatment
B. Be treated with topical fluoride, proper home care and observation.
C. Be smoothed with abrasive strips
D Be treated with fissure sealants
E.. Be restored with amalgam.
http://www.aapd.org/assets/1/19/Tinanoff11-02.pdf

22. 371#1
Which of the following is NOT a function of the wedge in the restoration of a Class
II cavity with amalgam?
A. It separates the teeth to allow restoration of the contact.
B. It assists in the adaptation of the matrix band to the proximal portion of the
preparation.
C. It absorbs moisture from the cavity preparation, allowing the restoration to be
placed in a dry field.
D. It provides stability to the matrix band and retainer assembly.
preoperative wedge
should be placed firmly into the gingival embrasure. This causes separation of the
operated tooth from the adjacent tooth and creates some space to compensate for
the matrix thickness that will be used later in the procedure
• depress the gingiva apically
■ cause minimal separation
■ minimize oozing of fluids through the rubber dam