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 castingsClinical Apsect Dental material. Composite Resine (pag 399)

Pag355 # 7Which 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 toothunlike conventional amalgam tooth preparations, theconventional tooth preparation for composite does notusually incorporate secondary retention features; doesnot require 90-degree composite margins, is usuallymore conservative in extensions; and is left with roughened,rather than smooth, preparation walls.Ref Art and science of operative dentistry Pg 551

Pag357 # 2The most accurate indicator of caries activity in root caries lesions is to A. assess the colour. B. evaluate the hardnessC. use bitewing radiographs. D. apply caries detector dyes

Textbook of Operative Dentistryedited by Nisha Garg, Amit Garg Pag 85

Pag357 # 3An 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 2006By Saravanan Pag 77

Pag358 # 5Which 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.)

Pag360 # 1A 10-15 second application of 37% phosphoric acid on prepared dentin will result in all of the following EXCEPTA. elimination of the smear layerB. 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 tubulesthat 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 theentire exposed dentinal surface (p<0,001);4. intertubular dentin surface percentage decrease overall exposed dentinal surface (p<0,001);5. appearance of the dentin surface porous zone containingsmear layer and demineralized residual collagenparticles with dentin demineralization products inacid globules (p<0,001); and6. complete dissolving of peritubular dentin cuff (p<0,001).Influence of Different Etching Times on Dentin Surface Morphologyetching of dentin and rinsing removes the smear layer, leaving asmooth surface with patent tubules. Demineralization of the dentin surfaceand subsurface is known as the total etch technique;( Dental Materials at Glance Pg 71)

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 motionand 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

Pag361 # 5Which 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.

[click here to read article]

Pag361 # 7What is the name of the process by which carbamide peroxide bleaches the teeth? A. Oxidation. B. Addition. C. Subtraction. D. Hydrogenation.

Carbamideperoxide, a weaker oxidizing agent, breaks down into hydrogenperoxide and urea.Clinical aspects dental material Pg 226

Pg363#4Compared 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 stableProducts that are properly heat-cured are a bit stronger andtougher than cold-cure acrylic resinsClinical Aspect dental Material Pag 155

Pag367 # 1The earliest colonizers of dental plaque are A. Gram-positive rods. B. Gram-positive cocciC. 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 acidStreptococcus mutans and Lactobacilli are the most common cariogenicbacteria in coronal caries.■ Actinomyces viscus (gram posotive) is the most common cariogenic bacteria in root surfaceor smooth surface caries.■ Dental plaque organisms—Streptococcus sanguis found earliest■ Other offenders: Actinomyces naeslundi, Veillonella, Streptococcus salivarious

Pag366 # 7Which 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 Dentistryedited by Nisha Garg, Amit Garg Pag 85

Pag366 # 8What is the most likely cause of food impaction at the site of a recently placed Class II composite resin restoration? A. Inadequate proximal contactB. Gingival overhangC. Inadequate marginal ridge morphology. D. Poor oral hygiene

Ideal contacts serve byMaintaining 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): 330–336Optimizing tooth form with direct posterior composite restorations

368 pag 6Which 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 importantareas, and restorations in patients allergic or sensitive to metals. The ADA does not support the use ofcomposites in teeth with heavy occlusal stress, sites that cannot be isolated, or patients who are allergic or sensitiveto composite materials. If composites are used asindicated, the ADA further states that "when used correctlyin the primary and permanent dentition, the expectedlifetime 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

368 pag 7During 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 FRACTURESCauses 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 carvingOperative dentistry 2000 pag 667

Pag 368 # 8Bevelling 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

369#1Which 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 materialOperative dentistry 2000 pag 126

369#2A dry and crumbly mix of amalgam can be the result of A. under triturationB. over triturationC. high copper contentD. lack of zinc content

Under-triturated amalgam has a mushy grainy feel because not all of the particlesare 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 expansiontime, ↑creep.■ Properly triturated = shiny, smooth, and homogenous.

369#8A 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 Years1. Repeat 12- to 24-month procedures every 6 months oras indicated by the individual patient's needs/susceptibilityto disease. Provide age-appropriate oralhygiene instructions.2. Complete a radiographic assessment of pathologyand/or abnormal growth and development, as indicatedby the individual patient's needs.3. Scale and clean the teeth every 6 months or as indicatedby the individual patient's needs.4. Provide topical fluoride treatments every 6 months oras indicated by the individual patient's needs.5. Provide pit and fissure sealants for primary and permanentteeth as indicated by the individual patient'sneeds.Dentistry for the Child and Adolescent by Mcdonald Pag 4

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372#1A 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 treatmentB. Be treated with topical fluoride, proper home care and observation.C. Be smoothed with abrasive stripsD Be treated with fissure sealantsE.. Be restored with amalgam.

http://www.aapd.org/assets/1/19/Tinanoff11-02.pdf

371#1Which 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 wedgeshould 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