Smart Dental Revision Suraj Kumar
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Dental Material, Operative Dentistry and ProsthodonticsCHAPTER 1

  • ➢ Physical Properties
  • ➢ Impression Material
  • ➢ Gypsum Product
  • ➢ Amalgam
  • ➢ Pin Retained Restoration
  • ➢ DFG
  • ➢ Cements
  • ➢ Composite
  • ➢ Denture Base Resin
  • ➢ Ceramic
  • ➢ Metallurgy
  • ➢ Caries
  • ➢ Instruments and Miscellaneous
  • ➢ Prosthodontics
  • ➢ Some More Notable Points from Prosthodontics
  • ➢ Some More Important Points from DM + OD + Prosthodontics
  • Glass Transition Temperature:
  • Benzold – Bruck effect (PGI 11) vs Metamerism
  • Munsell ‘s system measures and defines color quantitatively
    (AIIMS Nov. 10, AIPG 07)
  • Water contact angle:
  • 2Poisson's ratio:
  • Stress: It is the Internal [Q] resistance against applied force/load
  • Elastic Limit “Maximum stress” > proportional limit
  • Permanent distortion occurs when ELASTIC limit is exceede
  • Proportional limit = GREATEST stress
  • toughness
  • Bingham Body behavior:
  • 3Stress strain graph:
  • Moe:
  • Cote of different material in comparison to enamel (11.4):
  • COMPRESSIVE strength of:
  • ULTIMATE tensile strength:
  • High compressive strength + low tensile strength = Brittle (ceramic and amalgam)
  • Types of Stress and Force responsible:
    zoom view
    Fig 1.3: Shear
    • Shear stress – result of 2 set of forces parallel to each other
  • KHN values:
  • Hardness Test: Is the resistance to abrasion and indentation
  • NOTE:
  • Gold is the most ductile and malleable
  • Ag is the 2nd most ductile and malleable
  • Enamel is stiffer and brittle than DENTINE.dentine is flexible and tougher (resistance to fracture)
    zoom view
  • 5Brazillian Test:
  • Maxwell Voigt model:
  • Solid solution:
  • Eutectic alloy:
  • Peritectic alloys:
  • Concept:
  • M.p:
  • Thermoset material – chemically set material
  • Thermoplastic material – temperature affects setting
1. Angle between adhesive and aderend is zero. It me Ans.
(AIPG 08)
Ans. Complete wetting of surfaces (Ref: Craig's 12/e p18 -20)
2. The forces that hold atoms together are called:
(KCET 10)
Ans. Cohesive forces
3. If rate of loading is increased, the mechanical properties of a material:
(AIIMS Nov. 09)
Ans. Increases (Ref: Journal of the American Concrete Institute, 1980; 77: 1 – 212)
4. Which of the following decreases with strain hardening?
(PGI Dec 11)
  1. Hardness
  2. Strength
  3. Proportional limit
  4. Ductility
Ans. d. (Ref: phillip's 11/e p74)
5. Which decreases with surface hardening?
(PGI Dec 11)
Ans. Percentage elongation + corrosion resistance (Ref: Phillip's 11/e p576)
6. Wire hardening at low temperature of orthodontic wire would enhance all EXCEPT:
(PGI Dec 11)
  1. Stiffness
  2. Resiliency of wire
  3. Brittleness
  4. Ductility of wire
Ans. d. (Ref: Phillip's 11/e p576)
7. Tempering of steel:
(PGI Dec 10)
Ans. Increases it's toughness (Ref: Phillip's 10/e p641)
  • Dustless alginate: is made by coating with glycerine (if glycerine Not given in option go for Glycol/Dihydric Alcohol)
    (AIIMS Nov. 09)
  • Concept: Controlling S.T for alginate/ZnOE
  • 7ZnOE:
  • ZnOE:
  • for Dimensional Stability:
  • Agar and Gypsum Hardener:
    (AIIMS Nov. 10, AIPG 07) (Important for KCET)
  • Type 2 silicone impression material → additional silicone
  • Type 1 ZnOE → HARD type 2 ZnOE → SOFT
  • In NON-eugenol → HV – EBA is a substitute for eugenol (KCET)
  • The MOST COMMON impression material for INDIRECT CASTING: additional polysilicone [Q]
  • FLUORIDE release: [Q]
  • Stages of addition polymerization:
    zoom view
  • Clinical implication of high tear strength of PolyS:
  • 8Impression Compound:
    (PGI 10)
  • Polysulfide vs additional Silicone:
  • SNAP test:
  • W.T of dental materials:
  • Multiple pour/multiple casts → Addition polysilicone/polyether
  • Optimal thickness of elastomeric impression material → 2-4 mm
    (KCET Q)
  • Spacer thickness – 2 mm
  • Putty – Wash technique:
  • Surfactant → is added to polyvinyl siloxane to make it hydrophilic
    (AIIMS Q)
  • Multiple mix technique → heavy + light body
  • Single Mix technique → medium viscocity of elastomer is, single mix don't have high viscocity
  • Custom Tray: used in polysulfide. {advantage – less material required. So, less polymerization shrinkage} [Q]
  • Brush Heap → found in agar
  • ZnOE paste → most commonly used wash/final impression for edentulous jaw.
    (BHU 07)
  • Elastic Impression material: hydrocolloid + elastomer
  • BOTH silicones (addition and condensation) cannot be used with “Latex gloves”
  • Polysulfide vs Condensation Silicone:
  • C2H5OH [Q] is by product of condensation silicone is a larger molecule than H2O [Q], a by product of PolyS (Remember)
  • 9PolyS:
  • Polyether:
  • Too rapid polymerization + incomplete polymerization + improper P/L
  • Rough and irregular surface on impression (Very Important Q for NEET)
    (AIPG 10, 07)
  • Catalyst:
  • Addition silicone:
  • FLOW of type 1 impression compound:
  • Of type 2 impression compound:
  • Impression of hyperplastic tissue/flabby tissue:
  • Additional silicone → material of choice for OSMF patient in closed mouth technique as it has excellent flow
    (AIPG 08)
  • NOTE: (important for AIPG/AIIMS)
  • 10Plasticizer:
  • Accelerator vs retador:
    • ZnOE/impression paste
    • Zinc acetate (AIPG), CaCl2, ZnCl2 (AIPG 07),
      MgCl2, ZnSO4, alcohol, H2O [Q]
    • PGI 11
    • TRICK all oily compound
    • Mineral oil, waxes petroleum jelly, glycerine
    • agar
    • 2% K2SO4 (also called gypsum hardener)
    • Accelerate setting reaction of
    • Borax ses strength and
    • Ces viscosity of agar
    • alginate
    • Ti fluoride (gypsum hardener
    • Trisodium PO4
    • gypsum
    • K2SO4, Na2SO4, NaCl upto 2 %, gypsum (acts as nuclei of crystalisation)
    • TRICK:A B C
    • A – Acetate
    • B - Borax
    • C - Citrate
  • NOTE:
  • HYDROCOLLOIDS and ELASTOMERS should be removed by sudden jerky [Q] motion as they are viscoelastic material. This is to prevent permanent deformation [Q]
  • AGAR:
  • Laminate/agar – alginate method:
  • In case of Polyether, stone cast can be easily poured but removed with difficulty.
    (KCET 11)
  • In case of condensation silicone, polymerization is accompanied with repeated elimination of small molecules
    (AIPG 10)
  • Concept:
  • 11“PPS”:
  • Buccal Frenum:
  • Remember: 8 muscles form modiolus EXCEPT zygomaticus MINOR and ala Nasi (COMEDK 07, PGI Dec 11)
  • For stability of denture tongue should rest on occlusal plane
  • Massetric notch:
    (AIPG 12)
  • Influence of CORONOID process on maxillary denture:
  • 12MOUTH temperature wax:
  • Hamular Notch = pterygomaxillary notch
  • Retromylohyoid curtain formed by:
    zoom view
    Fig 1.7: Retromylohyoid curtain
  • Influence of muscle on lingual flange:
  • Points to Remember from Impression Materials (a final conclusion)
1. Working time of elastomeric impression material is defined as:
(AIPG 10, 07)
Ans. Time from start of mixing till just BEFORE the elastic properties have developed (Ref: Phillips 10/e p142)
2. For ZnOE, all of the following are true EXCEPT:
(AIPG 08)
  1. Olive oil is used as plasticizer
  2. Addition of methylmethacrylate increases strength.
  3. Addition of o – EBA in concentration of 37 – 50 % increases strength
  4. Rosin decreases the brittleness of set cement
Ans. c (Ref: Craig's 12/e p498)
133. All of the following is used as accelerator in ZnOE except?
(PGI Dec 11)
  1. Acetic acid
  2. Znic acetate dehydrate
  3. Bromoglycerine
  4. Calcium chloride
Ans. c (Ref: phillips 10/e p181)
  • ADA number = 25
    (COMED K 11)
    to remember S.E:
  • Minimum requirement of SE for GP:
  • 14Factors affecting S.E of G.P: (ALL points have been asked as Q)
  • H2O of reaction for setting of G.P = 18.6 ml
  • Gauzing H2O does not react. So, S.T of G.P independent of it
  • Soluble plaster:
  • Setting reaction of G.P:
  • Cynoacrylate:
  • Fluidity measurements:
  • Terra Alba: set CaSO4. 2H2O act as accelerator [Q]
1. The safest method for soaking dental cast is:
(COMED K 11)
Ans. Placing in a saturated solution of calcium sulfate
2. The strength of gypsum products is generally expressed in terms of:
(KCET 10)
Ans. Compressive strength
  • Composition of amalgam: (a favourite topic of PGI)
  • 15HIGH Cu amalgam is formed by irregular + spherical particles
    (KCET 10)
  • Delayed Expansion:
  • Delayed Contraction:
  • NOTE: In composition of amalgam only Sn ↓ses expansion while Ag and Cu ↑Ses expansion.
  • SPHERICAL amalgam requires less condensation force than lathe cut
  • Phases in amalgam alloy:
  • Order of Corrosion Resistance:
  • Lathe cut vs Spherical alloy:
  • Indisper:
  • Compressive strength of amalgam:
  • Tensile strength of amalgam:
  • Appearance of amalgam:
  • Under/Over Trichuration:
  • BUT
    ↑ Ses CREEP in BOTH lathe cut and spherical
  • Creep and Mercuroscopic Expansion:
  • NOTE: Content of Hg is 2-3 % higher at margin
  • Degradation of high and low copper amalgam:
  • Marginal defect best measured by Mahler's scale
    Range of value – 1 to 11 for amalgam
  • Corrosion Products:
  • Penetrating type of corrosion NOT seen in high Cu AMALGAM
    (AIPG 10, 09, AIIMS Nov. 09)
  • Facts About Hg:
  • Cavity width for class 1 and 2
  • Axial wall pulpal depth (into dentine): for class 2
  • 20 retention in class 2:
  • 20 retention feature in class 3
    zoom view
    Fig 1.8: Secondary retention feature in class 3
  • 20 retention in class 5:
  • Internal and External line angle:
  • Locks and high Cu amalgam:
    Does not require locks as they exhibit less creep
  • Butt joint vs Slide fit:
  • Number of line angle and point angles for class 1, class 2 and MOD:
  • Supporting cusp = centric holding/stamp cusp/functional cusp
    (KCET 12)
  • cavosurface angle of amalgam cavity preparation should be at right angle
    (AIPG 07)
  • Clearance with adjacent tooth:
    • Of gingival seat
    • Of facial and lingual proximal wall
    • 0.5 mm
    • 0.2 mm
  • 20In class 3 preparation it is acceptable to place enamel margin in area of contact
  • Reverse ‘S’ curve:
  • Cavity preparation in class 1:
  • Gingival extension of restoration:
  • Concept:
  • Resistance form:
  • For class 2 cavity preparation on maxillary permanent 1st molar:
  • class 5 cavity
    (Important for NEET and AIIMS):
  • Class 3 cavity (Important for NEET and AIIMS):
1. Pre carve burnishing is useful for all except:
(AIPG 12)
  1. Removes old amalgam restoration
  2. removes excess Hg
  3. initiates carving
  4. margin of amalgam is well condensed.
Ans. a. (Ref: Sturdevant 4/e p682 – 683)
2. When bonding of amalgam is required in orthodontic practice which of the following is selected for the purpose:
(AIIMS Nov 12)
Ans. 4 – META (Ref: Orthodontics – current principle and practice by grabber 4/e)
3. Discoloured areas seen through the enamel in the teeth that have amalgam restoration are known as:
(KCET 11)
Ans. Amalgam blues.
4. In case of deep carious lesion incomplete debridement is done to:
Ans. Prevent pulp exposure and allow a thin layer of a dentine to remain (Ref: Sturdevent 4/e p128)
5. In class 2 cavity for amalgam in case of permanent teeth, axiopulpal line angle is?
(PGI Dec 11)
Ans. Beveled in permanent teeth (Ref: Sturdevant 5/e p746)
6. LCOTE of amalgam as compared to tooth structure is about:
(PGI june 10)
Ans. 2.5 times (Ref: Phillips 11th ed pf 55, 419)
  • Provide MAINLY 1° retention [Q]
  • SELF threaded pin:
  • Cemented pin:
  • Contraindication for pin retained restoration is hypoplastic tooth. [Q]
  • Advantage of PIN retained restoration:
  • PIN retained restoration (Rule of Thumb)
  • Pin retained restoration ↓ses strength of amalgam
    (AIPG 11, 09)
1. One of the following is not true regarding pin retained restoration:
  1. Pin holes should never be prepared at different levels on the tooth
  2. A minimum of 0.5 mm clearance should be provided around the circumference of the pin for adequate condensation of the amalgam
  3. Pin hole should be located on a flat surface that is perpendicular to the proposed direction of the pin hole
  4. The pin hole should be positioned no closer than 1 mm to DEJ and no closer than 1.5 mm to the external surface
Ans. a
2. In pin – retained amalgam restoration, failure is more likely to occur at the:
Ans. Pin dentine interface (Ref: sturdevent 4/e p783)
  • It is an ideal material for class 5 cavity preparation
  • Bridging:
  • Difference of cavity for DFG from that of amalgam:
  • 23Classification of DFG:
  • 24 karat gold = 1000 fineness
  • Material providing BEST marginal seal/intergrity = DFG
  • Electra alloy RV:
  • Silicate cement has highest compressive strength while resin cement has highest tensile strength.
  • both GIC and silicate are contraindicated in mouth breadthers
  • Classification of GIC:
  • Metal Reinforced Gic:
  • 24Type 3 GIC i.e GIC Liner:
  • GIC:
  • High Viscosity GIC = RMGIC/light hardened GIC introduced in 1990
  • GIC adheres to tooth surface by carboxyl group of polymer chain
    (AIIMS May 10)
  • Compomer:
    • Properties inferior to composite BUT superior to GIC and RMGIC fluoride content:
  • GIC has maximum fluoride releasing capacity BUT silicate has maximum fluoride content. So, minimum 20 caries associated with GIC
  • bilayered/sandwich/laminated technique:
  • Main disadvantage of GIC → film thickness (thick film)
  • Remember: GIC recommended in root caries because of anticariogenic property
  • After 24 hrs of setting GIC has greater tensile strength BUT less compressive strength than ZnPO4
  • Concept:
  • 25Zynomer/buffered GIC:
  • Advantage of RMGIC over GIC:
  • Vitrabond/vitrebond:
  • RMGIC base/liner
    (PGI 12)
  • Resin cement = flowable resin base composite material
  • NON–eugenol cement → Vanilate ester
  • CERAMIC restoration/laminates are cemented using resin cement.
  • e.g of chelation reaction:
  • ZnPO4 cement:
  • Silicate cement:
  • Luting agent and their chief concern:
  • Varnish:
  • Concept:
  • 27Base:
  • Liners
  • VARNISH and ZnOE contraindicated under composite
  • W.T of dental materials:
1. A radiopaque area is observed in the dentine underlying a 3 month old class 2 amalgam restoration. Which base was used in this restoration?
(AIIMS Nov 10, Nov 08, AIPG 08)
Ans. Ca(OH)2 (NBDE Q)
2. To prevent damage to pulp in a deep cavity from acid etching, the cavity is lined by:
(AIIMS Nov 10, May 09)
Ans. RMGIC (Ref: sturdevant 4/e p175-76)
3. Sequence of setting of GIC is:
(AIPG 09)
Ans. Decomposition, migration, gelation, hardening
4. Which of the following is true for hybrid ionomers:
(AIPG 08)
  1. Release of fluoride more than compomer
  2. Fluoride release is comparable to conventional GIC
  3. More sensitive to water contamination compared to conventional GIC
  4. More ionic activity compared to conventional GIC
Ans. a.
5. A diagnosis of small occlusal cavities is most readily made by:
(AIPG 08)
Ans. An explorer and compressed air
6. Which GIC developes early resistance to water intake on setting?
(KCET 11)
Ans. RMGIC (Ref: Phillips science of dental materials 11/e p482)
7. For accurate interocclusal records the material of choice is:
Ans. ZnOE bite registration material
8. Which dental cement is most kind to pulp?
(AIIMS Nov. 09)
Ans. Zinc polycarboxylate (Ref: Albers. Tooth colored restoratives: Principles and Techniques 9th ed pg 71 – 73)
  • Composition:
  • Radio opacifier added to composite → TiO2 + Zr oxide
    (PGI Dec 11)
  • BIS – GMA in composite replaced methacrylate based matrix.
    (KCET 10)
  • higher filler content → reduced H2O absorption
  • Coupling agent → provides HydrolytiC stability (organic silanes)
  • Filler size: (favourite Q of PGI)
  • Visible light composite:
  • Shade matching should be done within 5 sec to avoid fatigue to eye
    (AIPG 12)
  • Bond:
  • Filler content: (favourite Q of PGI)
  • Microfilled composite shows more water absorption as compared to light cure composite/conventional/hybrid composite
    (AIPG 07).
  • Compomer:
  • 29Flowable composite: Used in
    (KCET 12)
  • Concept:
  • NOTE: Etching time for:
  • Curing time – 20 sec
  • Enamel rod gets dissolved by acid the most in head region
    (AIIMS Nov 09)
  • NOTE: Etching
  • In Acid etching GEL form is preffered over solution form for providing ease of placement over area to be etched
    (AIIMS May 12, Nov. 10, 08)
  • Type of acid etching:
  • Etchant concentration:
  • Etchant removes/modifies smear layer primer:
  • Concept:
  • Amalgam bonding system:
  • In PMMA P/L ratio:
  • Class 5 cavity:
  • Among lasers, only Argon laser is used to cure composite (AIPG 10, COMEDK 11). it emits single wavelength [Q]
  • Curing:
  • Depth of curing of composite by light → upto 2 mm (can correlate it with the effective depth of topical LA which is upto 2-3 mm)
  • Copolymerisation:
  • 31Smear layer thickness:
  • Conservative approach for restoration:
  • Bonding Agents (favourite Q of KCET)
  • Etching:
  • Uses of DBA:
    (PGI Dec 11)
  • Permeability of dentine depends on:
  • Fluoride release:
  • Curing:
  • Polymerization Shrinkage:
  • 32Polymerization stress can be minimized by:
  • C – Factor:
    • We have to minimize C – factor to reduce polymerization shrinkage
    • Class 1 = 5 class 2 = 2 class 3 = 1 class 4 = 0.5 class 5 = 0.25
      [Trick = 521 number ki BUS 0.5, 0.25]
    • [in KCET 2012 class 5 was asked but the answer was given as 0.5. we are sorry to say but even if it is given in sturdvent, you need to mark the same answer if Q is asked in future in KCET as they keep following their own key]
  • Microleakage in composite → more as LCTE is 3 times of teeth
  • Polishing:
1. While restoring a cavity, C factor is associated with:
(AIPG 12)
Ans. Polymerization shrinkage (Ref: Sturdevant 4/e p203, 243, 479)
2. Shade matching should be done within _______________ seconds to avoid fatigue of eyes to color.
(AIPG 12)
Ans. 5 seconds (Ref: Rosensteil, land, fujimoto 06, p724)
3. While restoring a tooth with composite resin, the etched surface gets contaminated with saliva accidently. what would be done next:
(AIPG 11,09)
Ans. Wash with water, dry area and continue restoration.
4. Class 5 cavity prepared for amalgam and composite differs in:
(AIPG 09)
Ans. Cavosurface margin (Ref: Sturdevant 4/e p528 – 531)
5. HOW long does it take for an etched enamel to return to normal condition?
Ans. 30 days (Ref: Charbeneau's principle and practice of operative dentistry 3/e p163)
6. In etching of enamel, the depth achieved is:
(AIIMS Nov 10)
Ans. 5–50 μ (Ref: Heasmen. Restorative dentistry, pediatric dentistry and orthodontics p104)
  • In PMMA:
  • 33If acrylic resin is packed in sandy state → Porosity occurs
  • Properties:
  • Residual Monomer:
  • Concept:
  • Most important disadvantage of Acrylic resin is polymerization shrinkage like composite
  • Resin packed in dough state because the material will be more homogeneous and occurrence of porosity is minimized
  • Curing of denture base resin:
  • Repair of fractured denture base:
    Chemically cured resin → MORE stable → but durability decreased
  • Properties of PMMA:
  • 34Disadvantage of PMMA:
  • In resin gas inclusion porosity → seen in fluid resin porosity due to air incorporation [NOT due to heating of resin]
  • Self cure are more porous than heat cure. So, to prevent porosity, self cure resins are cured under “VACUMM” pressure
  • Insufficient closure of flask during packing of denture base resin results in increase in vertical dimension (AIPG 07)
1. During polymerization of acrylic resin above what temperature benzoyl peroxide form free radicals:
(AIIMS Nov 12)
Ans. 60°(Ref: Phillips 11/e p730)
  • Composition:
  • PFM:
  • Porcelain teeth:
  • Bonding of ceramic to metal occurs both by mechanical and Chemical
  • Self Glazed Porcelain
  • More permanent than apllied glaze
  • APF gel/other topical fluorides can cause staining
  • investment used for casting of ceramic → phosphate bonded
  • Castable glass ceramic/machinable glass ceramic → DICOR
  • Injection moulded ceramic → IPS empress
  • Glass infiltrated ceramic → inceram
    (KCET 10)
  • 35Method of decresing porosities in ceramic:
  • Firing in porcelain: (stages)
  • High fusing = 1290 °C – 1370 °C (1300)
  • (Used for denture teeth)
  • Medium fusing = 1090 °C – 1260 °C (1300 – 1100)
  • Low fusing = 870 °C – 1090°C (900 – 110
  • Condensation shrinkage during porcelain firing is determined by particle size and shape (AIIMS Nov. 10, AIPG 07)
  • NOTE:
  • Strengthening of porcelain
  • In aluminous porcelain alumina interrupts the crack propagation by the process of dispersion strengthening
  • CAD – CAM → No need for “impression” and “casting” procedure [Q]
1. Common between amalgam and ceramic is:
(AIPG 12)
Ans. High compressive strength and low tensile strength (Ref: Manapalli 2/e p372)
2. For a cast porcelain inlay, the facial wall should:
(AIPG 09)
Ans. Diverge facially (Ref: Sturdevant 4/e p579 – 580)
3. Ceramics fired to metals are processed by:
(KCET 11)
Ans. Sintering (Ref: craig's 11/e p553-554)
  • Co – Cr/elgiloy:
  • In austenite (18 – 8 steel):
  • Zn: Scavenger of O2 (Deoxidizing agent added to dental alloys)
    (PGI Dec 11)
  • Ti: Most corrosive resistant
  • Casting Difference between base metal and Au alloy:
  • Sensitization and stabilization of stainless steel:
  • The only nearly pure metal used for dental casting is PURE titanium (Cp Ti) [Q] [donot confuse with DFG. It is pure Direct restorative material]
  • Cp Ti is most biocompatible
    (PGI 11)
  • Noble metal alloy (casting) classification:
  • Noble metal are resistant to corrosion because they have positive EMF
  • Implant material:
    (KCET Q)
  • 37Fluoride flux:
  • Types of flux:
  • Antiflux:
  • Base metal vs Noble metal (e.g Au)
  • GRAIN refiners:
  • Nickel:
  • Soldering vs Brazing:
  • Ideal temperature of H2O bath for softening fluid wax 51 – 54°C
  • Heat treatment
    Softening Heat
    Hardening Heat Treatment/Age Hardening
    Cold Working/Strain Hardening/Work Hardening
    All Strength (Including Tensile Strength) Decreases Except Ductility (It Increases)
    • All strength increases
      EXCEPT ductility which decreases (PGI 11)
    • Increases strength BUT decreases ductility (PGI 11) (same improvement properties as after hardening heat treatment.
    • Grain elongation is the result of cold working
    • Corrosion resistance reduces
      (PGI 10)
    • Usually For Au Alloys
    • Done for DFG, stainless steel wire
  • 38NOTE: With surface hardening percentage elongation reduces
  • Cold working of Dfg:
  • Tempering of steel increases hardness
    (PGI 10)
  • Wrought alloy → “cold worked” metal → hardness and tensile strength increases but ductility reduces
  • Ni added to cast Au alloy → Strengthner
  • Berrilium increases castability of BASE metal alloys
  • Fig 16: change in properties with cold working and annealing
    zoom view
    Fig 1.16: Change in properties with cold working and annealing
  • Grain elongation seen in cold working:
  • Wax Patern
  • Best technique: Direct – indirect
    (PGI 12)
  • Wax Composition:
  • Impression wax is: Bite registration/corrective wax
  • Incomplete wax elimination → leaves CARBON → causes Shiny surface on cast
  • Distortion is most serious problem of pattern, due to release of Internal stress
  • Method to prevent Warpage in wax pattern:
    (AIPG 08)
  • Non – True wax:
  • PKT -2 is wax adding instrument
  • Indirect spruing:
  • Most common cause of incomplete casting → narrow sprue
  • Turbulence of alloy in sprue → due to position of sprue
  • Ideal Sprue: Hollow metal sprue
  • sprue attachment:
  • 40Investment material:
  • Ring Liner:
  • Success of removable die system associated to precise relocation on working cast
    (PGI 09)
  • DIE material:
  • Porosity in cast restoration
    (Very Important Topic)
  • Common Cause of porosity in denture:
  • Cavity preparation for Cast restoration:
  • Bevels: Types
  • Most important bevel for cast inlay → Gingival bevel
    (AIPG 11, 09)
  • Width of gingival bevel = 0.5 to 1 mm and merging with 2° flare
  • Onlay:
  • In inlay:
  • In onlay:
  • class 2 metal restoration:
  • 42Inlay vs Amalgam
  • In inlay lap – joint present:
  • Certain Clinical conditions and choice of restoration:
  • For Inlay:
  • Where to keep gingival seat?
  • Gingival extension of restoration:
  • For any Cast restoration (gold/porcelain):
1. Most common reason for incomplete casting when using a centrifugal casting machine is:
Ans. Narrow sprue
2. Which Zone of flame is used for melting alloys:
(AIPG 10, 07)
Ans. Reducing zone (Phillips 10/e p510, 627)
3. Fins and spines in casting may occur because of:
(AIPG 10)
Ans. Rapid heating (Ref: Phillips 11/e p328)
4. Which is not a noble metal?
(AIPG 08)
  1. Au
  2. 43Ru
  3. Ag
  4. Osmium
Ans. c
5. One of the following is NOT true about gypsum bonded investment:
(AIPG 08)
  1. Used for gold alloys
  2. 50 – 65% gypsum changes to form α – hemihydrates
  3. Heating range is 500 – 700 0C
  4. Heating of investment above 700 0C causes formation of SO2 from calcium sulfate
Ans. b (Ref: Phillips 10/e p472 – 473)
6. Which is not used as antiflux:
(AIIMS Nov 12)
  1. Graphite
  2. Boric acid
  3. Iron oxide
  4. Calcium carbonate with alcohol
Ans. b (Ref: Textbook of orthodontics – gowri Shankar 1st ed pg 761)
7. Solder and flux used for joining Elgiloy wires are:
(KCET 11)
Ans. Silver solder and fluoride flux
8. The ideal temperature for water bath for softening fluid wax is about:
(KCET 10)
Ans. 51 – 54 degree F
9. A casting shows round margins and smooth and shiny surface due to?
(PGI june 11)
Ans. Inadequate wax elimination (Ref: Dental materials and their selection by William J.O’Brien 3/e p435)
  • Difoti/Diagnodent
  • Pit and fissure caries vs smooth surface carie.
  • 44Forward caries:
  • Affected dentine has no bacteria
  • Earliest changes in incipient caries:
  • Eburnation/sclerotic dentine:
  • The non active carious lesion is distinguished by no pain on excavation of caries
    (AIIMS May 10, May 07, AIPG 07)
  • Reparative and sclerotic dentine deposition
  • NOTE: In response trauma/irritant all 3 types of dentine, i.e. reparative, 2°, and sclerotic are formed
  • minimum depth of demineralisation of carious lesion to be detected radiographically = 500 μm
  • Minimum dentinal destruction to be evident radiographically = 40 μm
  • dental caries associated with 8 serotypes of S. mutAns.
  • Streptococcus mutans and Lactobacillus:
  • Active caries → light brown
  • Non – active caries → dark brown/black
  • Root caries:
  • Arrested Caries:
  • 45Location of caries predominant organism: (very important in any examination)
  • TIME of progression from incipient to cavitated clinical caries on smooth surface = 18 month 6 month for deep pit and fissure caries:
  • Caries Diagnosis: Newer method of caries diagnosis
  • Different theories of caries:
  • Stephen Curve:
  • 46Generation of sealants:
  • Caries activity test:
  • Synder's test:
    • Colorimetric test. [Q]
    • Principle – measures salivary microorganism ability to form acid in carbohydrate media.
    • Medium has indicator – Br (green ph -5.4 → yellow ph 3.8) [Q]
    • Measures
    • Advantage: Simple, low cost.
    • Synder test – Measure speed/rate of acid production. [PGI].
    • Method/Yard Stick of detection is by Ph change. [PGI]
  • Lactobacillus count test:
  • Dyes used in staining fracture line in a suspected tooth – 2% iodine [Q]
  • Carisolv vs Caridex: They are alternative chemico-mechanical method for removal of caries.
  • Caries Vaccine:
  • 47Caries activity studies:
  • Sorbitol:
1. Streptococci is important organism in causing dental caries as it :
(NEET 13, AIPG 12)
Ans. Produces extracellular polysaccharides
2. Streptococci are acidophilic and aciduric. In this acidophilic means.
(AIPG 12)
Ans. Can survive in acid (Ref: Jawetz 23/e p65)
3. Which of the following is false regarding dental caries:
(AIPG 12)
  1. Infectious and transmissible
  2. Not caused by microbes
  3. Causes breakown of organic structure
  4. Possible without sucrose
Ans. b. (well known fact)
4. Bacteria are normally most populated in which area of teeth:
(NEET 13, AIPG 12)
Ans. Proximal
5. Caries assessment tool CAT developed by AAPD defines high risk group as all except:
(AIPG 12)
  1. Visible plaque on anterior teeth
  2. Atleast 1 area of demineralization
  3. Enamel hypoplasia
  4. Children with special health care needs
Ans. b (Ref: Mcdonnald)
6. Interproximal lesion Usually Begins:
(AIPG 11, 09)
Ans. Gingival to contact area (NBDE Q)48
7. Which is NOT true regarding S. mutAns.
(AIPG 10)
  1. Acidogenic and aciduric
  2. Requires specific conditions for growth
  3. Requires carbohydrate for metabolism
  4. Do not multiply easily
Ans. d (Ref: Clinical textbook of dental hygiene and therapy by Ireland, 2006 p77)
8. Which of the following is cariostatic?
(KCET 10)
Ans. Molybdenum and vanadium
9. Which of the following translucent area on hydration of tooth surface disappears?
(PGI Dec 10)
Ans. Incipient carious lesion (Ref: Sturdevant 4/e p408)
10. Best method for caries reduction is:
(AIPG 08)
Ans. Substitute sugar by alcohol based sugar.
11. Most cariogenic sugar is:
(AIPG 08)
Ans. Sucrose
12. Bacteria which adhere to tooth andcause caries is due to:
Ans. They produce extracellular polysaccharides.
  • Bur Description:
  • Antirust agent:
  • Formula for instruments:
  • 49Caries:
  • Enamel Bevel – given by GMT which is a type of Chisel [Q]
  • Noise levels in excess of 75 decible → causes hearing damage
    (AIIMS 06)
  • Enamel hatchet + GMT → chisel
  • Angle former → excavator
  • Thickness of matrix band (CLASS 2):
  • Burs:
  • Thickness of rubber dam:
  • Distance between 2 holes in rubber dam = 6.3 mm
  • Thick rubber dam provides better retraction of gingiva → so, used in class 5 cavities
  • Concept: A rubber dam does not require anything to pass
  • Isolation:
  • Size of diamond abrasive:
  • Abrasive hardness:
  • 50Air Abrasion:
  • Limit of Eccentricity:
  • Principal of Balance (for instrument)
  • Pressure applied:
  • Cavity preparation and temperature rise:
    Not > 60 °C/130 °F
  • factor influencing cutting efficiency of a bur:
  • Rake angle:
  • Cracked tooth syndrome:
  • Bitewing with RVG:
  • Crocus cloth = Pumice
  • Heat content of propane [Q] and butane is highest
  • 51Sterilisation:
  • Important Values:
    (Very Important)
  • Wedge:
  • Seperator:
  • Chisel:
  • 52Differentiating features of enamel hatchet from chisel:
    (AIIMS 06)
  • Excavator:
  • Speed:
  • Horning machine: Mechanical sharpener
    (KCET 02)
  • In Bur → increased edge angle → decreases chances of bur to
  • Fracture
  • Change in bur neck diameter, shape and size of the bur and clearance angle affects efficiency of bur But not taper of bur head/height of bur head
    (AIIMS 06)
  • For better efficiency and longer shelf life of a carbide bur, it should be rotated fast before entering cavity.
    (AIPG 11, 09)
  • Rubber dam clamp:
  • Critical/Non Critical instrument:
  • 53Laser:
  • Polishing Agent:
  • After amalgam polishing, the metal surface is flattened. This layer is called as Beilby's layer
    (AIIMS May 11, 08)
  • Agents for treating hypersensitivity are: NaF, SnF2, potassium nitrate
    (AIIMS 08)
  • 2 % NaF is commonly used in iontophoresis
    (AIIMS 06)
  • While restoring a tooth, following rules should be followed for maintaining aesthetics:
    (AIIMS 06)
1. It is essential to lubricate dam before applying it. Which of these is not a suitable lubricant?
(AIIMS May 11, AIPG 09)
  1. Shaving gel
  2. Liquid soap
  3. Scrub gel
  4. Vaseline
Ans. d (Ref: Sturdevant 5/e p467)
2. Which is the wrong way to apply dam using a wingless clamp?
(AIIMS May 11, AIPG 09)
  1. Put the clamp on the tooth, and then pull the dam over it.
  2. Place the dam on the tooth with fingers and then position the clamp over it.
  3. Attach the dam over the clamp and frame outside the mouth, and then put the assembly over the tooth using clamp holders over the dam.
  4. 54Place the dam over the clamp and frame outside the oral cavity and then on tooth using a holder under the dam.
Ans. c. (Ref: Sturdevant 5/e p471)
3. Interdental papilla are seen protruding beneath the rubber dam mostly when:
(AIIMS Nov 11)
Ans. Holes are placed too close (Ref: Sturdevant 5/e p469)
4. FACIAL occlusal line in maxillary arch is formed by:
(KCET 11)
Ans. Non supporting cusps (Ref: Sturdvent 4/e p38)
5. Right rear operator position refers to:
(KCET 11)
Ans. 11 O'clock position
6. The disadvantage of winged rubber dam retainer is that it interferes with the placement of:
(KCET 11)
Ans. Matrix band
7. Which of the following items in the dental operatory cannot be classified as a semi critical item?
(KCET 11)
  1. Suction tip
  2. Hand piece
  3. Endodontic file
  4. Water syringe tip
Ans. c.
8. Function of water retraction system is:
(KCET 10)
Ans. Retracts water whenever spray is stopped
9. Rubber dam is particularly adaptable to primary 2nd molar because the:
(KCET 10)
Ans. Cervical constriction of crown favours its retention
10. Which of the following laser is is having a wavelength in the visible light spectrum?
(PGI Dec 11)
Ans. Argon (Ref: Skinner's 11/e p412)
11. Safe level of Ni according to OSHA in clinics is?
(PGI June 11)
Ans. 1 mg (Ref: Sturdevant 5/e p165)
  • Working condyle/laterotrusive condyle
  • Non-working condyle/mediotrusive condyle
  • Bennet movement
  • 55Bennet angle:
  • Border Movements:
  • Vertical jaw relation:
  • Centric Relation:
  • Discrepency between centric relation and centric occlusion:
  • Thickness of inter – occlusal record – 2 mm
  • Orbitoaxial opening is determined by lateral pterygoid relining technique:
  • 56Note: If there is CR and CO discrepancy then it needs NEW denture face bow:
  • Tissue conditioner:
  • Main disadvantage of relining and rebasing:
  • Main disadvantage of SCD:
  • Immediate denture:
  • Jiffy denture is interim immediate denture hinge movement possible upto:
  • Condylar inclination – 20 - 25°
  • Average intercondylar distance in CD patient = 110 mm
  • Relationship of denture base that resists the dislodgement of denture in horizontal direction is stability (AIIMS 06)
  • Problems in new denture bearers:
  • Deflective occlusal contacts results in denture becoming loose several hours after wearing.
    (AIPG 08)
  • 57Anterior deprogramming device:
  • NOTE: Ideal support for implant – lamellar bone in patients requiring lingual frenectomy:
  • Biting Force: Measured by Gnathodynometer [Q]
  • Metallic Denture:
  • Appointment of Asthmatic patient is preffered in LATE morning/afternoon (AIIMS 06) patient type:
  • Denture cleanser:
  • Denture adhesive:
  • Shunting effect in CD:
  • Die hardener:
  • 58Mastication vs bruxism:
  • Contraindication for relining and rebasing: [Q]
  • Haspburg Jaw:
  • Arrangement of artificial teeth depends on ridge shape and arch form
    (AIPG 08)
  • Atwood classification of ridge:
  • Implant:
    (Very Important Topic for PGI)
  • Epulis fissuratum is the tissue reaction commonly seen due to overextension of labial flanges of complete denture
    (AIPG 08)
  • Rx of papillary hyperplasia:
  • Rx for hyperplastic ridge:
  • 59Factors affecting tooth preparation:
  • For abutment selection:
  • Crown: Root
  • Lateral incisor cannot be used as abutment as it has insufficient pericemental area.
    (AIPG 07)
  • Concept:
  • Taper:
  • Occlusal offset → given for structural durability [Q]
  • Functional cusp bevel→ provides adequate bulk to the restoration in area of heavy occlusal contact→ provides structural durability
  • Good ridge support required for FPD [Q]
  • If canine is missing abutments used is:
  • Resistance:
  • Grove should be atleast 1 mm wide
  • 60Cusp Reduction:
  • Angulation of functional cusp bevel:
  • Indication of partial veneer crown:
  • Concept:
  • Modifications 3/4th crown: (facial surface intact)
  • So, in tilted tooth → go for 3/4 th crown→ beter aesthetic + conservative
  • Compared to ALL ceramic, poor colour matching is main disadvantage of PFM
  • Fracture of PFM→ mainly due to inadequate design fabrication of restoration (NBDE Q)
  • Tooth Reduction:
  • Finish line:
  • 61Any crown is indicated in case of gross carious destruction but contraindicated in case of uncontrolled caries
  • All ceramic → incisal edge sloping towards lingual (not straight)
  • This bevel (17°) necessary for stress distribution
  • PFM → wing formation/vertical wall → increases retention and resistance
  • Aesthetic laminates:
  • Stainless steel:
  • For temporary restoration: among various material ZnOE is most commonly used
  • Natural glaze/self glaze → more permanent than applied glaze
  • For gingival retraction under chemicomechanical method:
  • Types of FPD:
  • RCT treated tooth with short root is contraindicated as abutment
  • Resin bonded bridge:
  • 62Connector: Non rigid
  • Pontic:
  • Post and Core:
  • DIE:
  • Bucco lingual edentulous space requiring cross arch stability RPD preffered
  • Too great bone resorbtion → RPD preffered as FPD requires proper ridge support
  • Pulp capped tooth should not be used as Abutment
  • Tooth with greatest pericemental area:
  • Maxillary 1St Molar (433 mm2) (Manipal)
  • in RPD:
  • Principals of Design of Rpd:
  • Major Connector: (very important)
  • 65Retention in RPD:
  • Direct retainer
    (Important topic for KCET)
    • TYPES:
      • Extracoronal
      • Intracoronal/internal attachment:
        • Mainly given for aesthetic reasons. abutment tooth shoud have a sound pdl + should fill all the criteria of abutment tooth + should be avoided in Distal extension cases without stress breaker (i.e can be given in distal extension cases with stress breaker)
        • Used in tooth supported prosthesis
        (PGI 12)
    • Clasp Passivity: It should be passive until dislodging force is applied
    • Circumferential clasp provides greater Stability due to “Rigid Shoulder” which is absent in bar clasp
    • Distal extension case and choices of direct retainer:
      • As in distal extension case there are high forces on abutment. So, we have to protect it from damage. choice of direct retainer are as follows:
        1. Circumferential clasp:
          zoom view
          Fig 1.29: Circumferential clasp
          zoom view
          Fig 1.30: Circumferential clasp
          Single circlet clasp:
          • High forces on abutment as very Rigid. So, can't be used
          • Reverse circlet clasp:
            Can be used with opposite rest, i.e. MesiaL rest involving distobuccal undercut.
        2. Bar Clasp:
          • Fulcrum line shifts mesially so, less force on the abutment.
          • But if only mesio – buccal undercut is retentive, then use
          RING clasp:
          zoom view
          Fig 1.31: Ring clasp
          zoom view
          Fig 1.32: Combination clasp
          Indications are:
          • Tipped molar (KCET 12)
          • Mandibular molar tipped mesio – lingually [Q]
          • Maxillary molar tipped mesio – buccaly [Q]
          • Back action clasp is a modification of ring clasp
      • Hair Pin/Reverse action/Fish Hook clasp: Uses mesial rest and engages same mesio – buccal undercut
      • Combination clasp:
        Flexible retentive arm of wrought alloy. So, less force on the abutment
      • Embrassure clasp: is always used with 2 occlusal rest
      • Multiple clasp: indicated when denture replaces entire half of the dental arch/when EXTRA retention is needed (KCET) as in case of periodontally weakened principle abutment (KCET 08)
      • HALF and HALF clasp: 2 minor connector for retentive and reciprocal arm
      • Advantage is DUAL retention [Q]
      • Indication is the isolated rotated abutment
  • Circumferential vs bar clasp:
  • Contraindication of BAR clasp:
    • Shallow vestibule
    • Large soft tissue undercut
  • Rest and Rest seat:
  • Indirect Retainer:
  • Non–anatomic teeth:
  • PPS + fovea palatine + vibrating line → Movable soft palate
  • 68Acrylic teeth vs Porcelain teeth
  • The mesial inner inclines of lingual cusp of maxillary 1st premolar is the most common initial Supracontact at resting centric position.
  • Selective grinding:
  • Curve of occlusion:
  • Incisal guidance:
  • For selective grinding and for clearly detecting discrepancy in occlusion
  • Remount on articulator with new inter-occlusal record
  • NOTE: It's an NBDE Q which has been asked in NEET 13. So, be thorough with all NBDE questions to crack NEET/AIIMS
  • 69Interim immediate denture/JIFFY denture:
  • In Overdenture:
  • Concept: Implant placement
  • Tooth most likely causing lateral balancing interferences: premolars (NBDE Q)
  • CD patients have a preference for which tooth while chewing hard food – premolars
  • Denture stomatitis/denture papillary hyperplasia:
  • Proximal groove :
  • Ferrule: Main advantage is to prevent vertical root fracture
  • New Concept:
  • In Co – Cr – Ni alloy/elgiloy:
  • The average distance between upper and lower sulcus in anterior region is 36 – 39 mm (38 mm) (AIPG Q, AIIMS 05)
  • Anterior lingual border forms 2° peripheral seal in mandible (NBDE Q)
  • The posterior determinant of occlusion has the greatest effect on the restoration of which tooth? (NBDE Q)
    Ans. Mandibular 2nd molar
  • Indication for Non-Rigid Fpd:
  • 70Occlusion:
  • The usual 1st STEP in occlusal adjustment is to eliminate prematurities in centric relation (NBDE Q)
  • NESBIT appliance:
  • While recording protrusive interocclusal record:
  • Height of contour:
  • Abutment tilted > 20°
  • Implant:
  • Applegate's Rule for classification of edentulous span:
    (Very Important for KCET and COMEDK)
1. While setting condylar guidance on a 3 pin articulator, the incisal pin is:
(AIPG 12)
Ans. Out of contact with the guide table (NBDE Q)
2. The chamfer finish line is used in:
(AIIMS May 10, May 08, AIPG 07)
Ans. Lingual surface of PFM (Ref: Shillinburg 3/e p132)
3. The replacement of missing part/artificial substitute is called as:
(AIIMS May 10, May 08, May 07, AIPG 07)
Ans. Prosthesis (Ref: Nallaswamy 1/e p810)
4. A porcelain laminate veneer during adhesion gets bonding interface from:
(AIIMS May 10)
Ans. Composite resin matrix, luting agent, etched enamel and silane coupling agent
5. A patient with complete denture complains of pain while swallowing. There is overextension of the denture in the distolingual aspect. The muscle involved is:
(AIIMS Nov O9)
Ans. Superior constrictor (Ref: Winkler, prosthodontics 1988 p76)
6. A complete denture patient with poor neuromuscular control wants correction of denture. it may be achieved by which of the following?
(AIIMS Nov O9)
Ans. Interocclusal records are made and corrected on articulator (winkler. essentials of complete denture prosthodontics 2/e p328)
7. After complete denture fabrication, if teeth are in end to end relation in patient, it can be corrected by:
(AIIMS Nov O9)
Ans. Grinding of the inclines so that the upper teeth move buccally and lower tooth move lingually.
8. A patient has come for relining and rebasing. You do relining if:
(AIIMS Nov O9)
Ans. If the patient is poor and cannot afford new denture (Ref: Nallaswamy 1/e p2003, p239-48)
9. In an edentulous patient, the average distance between the upper and lower sulcus in the anterior region is:
(AIPG 08)
Ans. 38 mm
10. To transfer the axis orbital plane we require:
(AIPG 08)
Ans. Either arbitrary/kinematic face bow (Ref: Bouchers 8/e p243)
11. Retentive arm in a clasp always points towards:
(AIIMS Nov 11)
Ans. Occlusal (Ref: Stewart. Textbook of RPD 2/e p67 – 68)
12. For strength and rigidity, the vertical height of a finished lingual bar should be atleast:
(KCET 11)
Ans. 4 mm
7213. A reliable guide for positioning maxillary anterior teeth in CD patient is:
(KCET 11, NEET 13)
Ans. Incisive papilla
14. Articulated diagnostic casts help in the following EXCEPT:
  1. Diagnostic wax up to evaluate outcome
  2. Detailed analysis of occlusal plane and occlusion
  3. Fabrication of wax patterns for casting
  4. Performing mock tooth preparation
Ans. c.
15. Height of contour term was coined by:
(KCET 11, COMEDK 11)
Ans. Kennedy
16. The functional occlusal force applied to the periodontal tissues during one deglutition is for a duration of:
Ans. 1 sec
17. The 1st person to employ mechanical device to determine the relative parallelism of tooth surface was:
(KCET 11)
Ans. Fortunati
18. Occlusal offset in an anterior partial veneer crown may generally be necessary to provide:
(KCET 11)
Ans. Structural durability
19. Mode of failure during dislodgement of prosthesis cemented with zinc polycarboxylate cement is usually seen at the:
Ans. Cement prosthesis interface (Ref: Phillips 11/e p112)
20. Hanau H2 articulator has an intercondylar distance of:
(KCET 11)
Ans. 110 mm (Ref: Wrinkle 2/e p23)
21. The technique to produce limited removal of epithelial tissue in the sulcus while a chamfer finish line is being created in tooth structure is called:
Ans. Gingettage (Ref: Shillingburg 3/e p268)
22. The ultimate finish line which produces an acute margin of metal is:
Ans. Knife edge (Ref: Shillingburg 3/e p132)
23. Schubiger attachment has a screw base common to the:
Ans. Gerber attachment (Ref: Wrinkler 2/e p23)
24. While arranging artificial teeth, the labial surfaces of the maxillary central incisors are usually ___________ in front of the posterior border of the incisive papilla:
(NEET 13, KCET 10)
Ans. 8–10 mm
25. Torus mandibularis is common on which area:
(KCET 10)
Ans. Lingual, premolar area
26. Functional cusp bevel has to be placed in following cusps EXCEPT:
(KCET 10)
  1. Mesiopalatal cusp
  2. Distopalatal cusp
  3. Distolingual cusp of mandibular molar
  4. Distobuccal cusp of mandibular molar
Ans. c.
27. Wing preparation for metal ceramic restoration helps in:
(KCET 10)
Ans. Retention and resistance.
28. During recording centric relation, compound occlusion rims with styli in maxillary arch are used in:
(KCET 10)
Ans. Needles house technique
7329. Mechanism of action of indirect retainers resembles:
(KCET 10)
Ans. 2nd class lever.
NOTE: Distal extension RPD is an example of 1st order lever.
30. Which of the following case is contraindication for FPD?
(PGI Dec 11)
Ans. Patients with high caries index
31. Which of the following is the most biocompatible material for dental prosthesis?
(PDI June 11)
Ans. Commercially pure titanium (Ref: Peterson 2/e p189)
32. Margins for all ceramic are?
(PGI June 11)
Ans. Shoulder on both buccal and lingual (Ref: Rosenstiel 3/e p175)
33. Which of the following position of mandible is in non-interfering occlusion?
(PGI June 11)
Ans. Centric occlusion (Ref: Boucher's 12/e p277)
34. In tooth preparation procedure, the foremost principle is:
(PGI Dec 10)
Ans. Conservation of what is remaining (Ref: Nallaswamy 1/e p567)
35. During jaw relations protrusive records are used for:
(PGI Dec 10)
Ans. Condylar measurement of both side (Ref: Winkler 2/e p195)
36. Golden proportion rule applies:
(PGI Dec 09)
Ans. 62 % (Ref: Sturdevant's 5/e p628)
37. The success of removable die system is based upon:
(PGI Dec 09)
Ans. Precies relocation of the die in the working cast (Ref: Shillinburg 3/e p314)
38. Inter papillary distance is equivalent to:
(PGI June 09)
Ans. Distance between the corners of mouth (Ref: Nallaswamy 1/e p234)
  • Addition polysilicones → type 2 silicone impression
  • Silicone impression materials → have Low W.T and S.T
  • In ZnPO4 cement → ‘Al’ present in liquid which is essential for cement forming reaction
  • Activator in composite:
  • Glycol ether/phthalate:
  • Glycol dimethacrylate → cross linking agent in denture resin → provide craze resistance [Q]
  • Bevel:
  • Microporosities and localized shrinkage porosities are Not seen in dentine base resin
  • Tooth Reduction:
  • Functional cusp bevel = 2 mm
  • Wing formation in PFM → for retention and resistance (Not aesthetic)
  • 74Resin Bonded bridge: main advantage is that it is Conservative [Q]
  • Pontic:
  • Major connector:
  • Tissue stops and beading:
  • Indirect retainer based on → class 2 lever [Q]
  • Implant:
    (Very important for PGI)
  • Hardness test:
  • Mercury/(Hg):
  • Compressive strength of dentine (268) < amalgam (310) < enamel (384)
  • 75Denture:
  • During lateral excursion:
  • Interferences in centric relation:
  • Loosening of denture while smiling → inadequate relief of buccal frenum [Q]
  • Gauze of wax:
  • Disadvantage of autoclave → causes fibro optic dimming
  • 24 karat = 1000 fineness
  • Fluoride flux → KF + boric acid (1: 1) [Q]
  • Bennet movement → 1 – 1.5 mm/side
  • Bennet angle → 15° [30° in edentulous patient]
  • Lingual flange in mandibular denture is characteristic ‘S’ shaped due to action of mylohyoid muscle [Q]
  • Tissue Conditioner → tends to harden in 4-8 weeks
  • Fluidity measurement of gypsum product:
  • Stages in addition polymerization: (KCET Very Important)
  • Indisperse → 10 % indium admix → decreases Hg vapour