All Free Dental Materials MCQs with Answers

• A. Microfilled resin
• B. Macrofilled resin
• C. Hybrid
• D. Light cure activated

Explanation: Microfilled composites contain a greater proportion of resin matrix, and the matrix absorbs more water than inorganic filler.

• A. Composites
• B. Unfilled resins
• C. Amalgam
• D. Polycarboxylate

Explanation: Unfilled resin undergoes marked polymerization shrinkage because it contains a high proportion of monomer, leaving marginal gaps that…

• A. Nd:YAG
• B. CO2
• C. Argon
• D. ER:YAG

Explanation: Argon laser emits blue-green light that can activate photoinitiators in composite resin, so it was used for light curing.

• A. Parabane
• B. Ligane
• C. Chelane
• D. Silane

Explanation: Silane is an organosilicon coupling agent that chemically links the inorganic filler surface to the organic resin matrix.

• A. Separate etching step is still required
• B. Separate etching step not required
• C. 4th generation bonding agents
• D. Contains only primer

Explanation: A one-bottle adhesive combines primer and bonding resin, but in the conventional fifth-generation etch-and-rinse system a separate…

• A. Decrease coefficient of thermal expansion
• B. Decrease polymerization shrinkage
• C. Decrease micro leakage
• D. Decrease porosity in restorative material

Explanation: Acid etching creates microporosities and increases surface energy, allowing resin to penetrate enamel and form micromechanical retention…

• A. 200 um - 250 um
• B. 3 um - 9 um
• C. 50 um - 110 um
• D. 10 um - 20 um

Explanation: Thirty seconds of phosphoric-acid etching produces a relatively shallow micromechanical retention pattern in enamel, commonly around 10–20…

• A. Quartz
• B. Silicates
• C. Zinc particles
• D. Aluminium

Explanation: Quartz is a common inorganic filler in composite resin and improves strength, wear resistance and stiffness while reducing polymerization…

• A. 300 mw/sm2
• B. 350 mw/cm2
• C. 400 mw/cm2
• D. 450 mw/cm2

Explanation: A quartz-tungsten-halogen curing unit should provide at least about 300 mW/cm² to polymerize composite adequately.

• A. Low compressive strength
• B. High water absorption
• C. High abrasive resistance
• D. High polymerization shrinkage

Explanation: Inorganic fillers give composite resin greater resistance to abrasion than unfilled acrylic resin.

• A. Zinc oxide
• B. Methyl methacrylate
• C. Phosphoric acid
• D. Eugenol

Explanation: Phosphoric acid selectively dissolves the superficial mineral of enamel, creating microporosities for micromechanical bonding.

• A. Is fiber optic
• B. Need no protection while in use
• C. Will cure composite upto a depth of 5 millimeter thickness
• D. Should be held at a millimeter distance from the restoration

Explanation: The curing tip should be held very close, approximately 1 mm from the restoration, because light intensity falls rapidly with distance.

• A. Amalgam alloy
• B. Unfilled resin
• C. Composite resin
• D. Direct filling gold

Explanation: Unfilled resin has a relatively high coefficient of thermal expansion, so temperature changes produce greater dimensional mismatch and…

• A. Increased thermal conductivity
• B. Decreased thermal conductivity
• C. Decreased wear resistance
• D. None of the above

Explanation: Composites generally have lower wear resistance than amalgam, particularly in high-stress or posterior applications.

• A. Increasing the mechanical strength
• B. Decreasing the coefficient of thermal expansion
• C. Reducing the polymerization shrinkage
• D. All of the aboveConsult Online Doctors

Explanation: The inorganic filler strengthens the composite, lowers its coefficient of thermal expansion, and replaces some resin volume, thereby…

• A. Polymerization shrinkage is greater if bonded surface area is lesser than unbounded surface area
• B. Polymerization shrinkage is high if within the enamel margins
• C. Acid etching and priming will decrease polymerization shrinkage
• D. Microleakage can occur because of polymerization shrinkageTry Prep Courses

Explanation: Polymerization shrinkage causes greater stress when the bonded surface area is large relative to the free, unbonded surface area, not when…

• A. TEGDMA
• B. Ti02
• C. BIS-GMA
• D. None of the above

Explanation: Titanium dioxide is an opaque pigment that masks the underlying tooth structure and gives composite its opacity.

• A. 30 seconds
• B. 60 seconds
• C. 90 seconds
• D. 120 seconds

Explanation: The conventional enamel acid-etching time is about 30 seconds, which produces microporosities for resin retention.

• A. BIS GMA
• B. Polymethyl methacrylate
• C. Benzoin methyl ether
• D. Silica filter

Explanation: Bis-GMA is a common dimethacrylate resin monomer in composite resins, many bonding agents, and resin-based occlusal sealants.

• A. Silica glass
• B. Barium glass and strontium glasses
• C. Organic matrix
• D. Fluoride particles

Explanation: Barium and strontium glasses contain high-atomic-number elements that absorb X-rays and make composite radiopaque.