1. Hypomineralized structure of the enamel rods and the inter rod substance is called

A. Enamel tuft
B. Enamel lamellae
C. Striae of Retzius
D. Prismless enamel

Answer- A

Enamel tufts consist of hypocalcified enamel rods and interprismatic substance that extend in the direction of the long axis of the crown.

2. True about dentin

A. Hardness 1/5th of enamel
B. Hardness less at the DEJ
C. Modulus of elasticity is 40 Gpa
D. Compressive strength is 384 Mpa

Answer – A

DEJ usually exhibits the presence of mantle dentin n which is less mineralized than the rest of the dentin. Modulus of elasticity of dentin is approximately 30Gpa. Compressive strength of dentin ranges from 250-350Mpa
The hardness value of enamel (HV = 274.8 ± 18.1) was around 4.2 times higher than that of dentin (HV = 65.6 ± 3.9).

3. Cusps that contact opposing teeth during maximum habitual intercuspation

A. Non functional cusp
B. Stamp cusp
C. Non holding cusp
D. Both A and B

Answer- B

Stamp cusps are also called supporting cusps or central holding cusps. These include the buccal cusps of the mandibular and palatal cusps of the maxillary posteriors cusps.

4. Stratum spinosum contains

A. Cuboidal cells
B. Extremely flattened cells
C. Extremely flattened and dehydrated cells
D. Tonofibril bundles

Answer- D

This layer comprises of irregular polyhedral cells with abundant tonofibrils and prominent intercellular bridges

5. False about the circumvallate papillae

A. 8-12 in number
B. Located adjacent and posterior to the sulcus terminalis
C. Surrounded by a sulcular groove
D. None of the above

Answer- B

Circumvalllate papillae are partially keratinized papillae that are located anterior to the sulcus terminalis

6. Diameter at D16 for No.20 Reamer

A. 0.20
B. 0.32
C. 0.52
D. 0.62

Answer : C

Diameter at D0 for No.20 Reamer = 0.20 mm
Taper = Diameter increase per millimeter = 2 % = 2/100 = 0.02 mm
Diameter increase at 16 mm = 0.02 X 16 = 0.32 mm
Diameter at D16 = 0.20 + 0.32 = 0.52

7. Distance from one cutting edge to the next in an endodontic instrument is called

A. Land
B. Pitch
C. Flute
D. None of the above

Answer- B

Pitch is the distance between two cutting edges Flute is the space between two cutting edges Helical angle is the angle formed by the blade to the long axis

8. Risk indicators for caries

A. White spots
B. Visible plaque
C. Deep pit and fissures
D. Both B and C

Answer- A) White Spots

9. Recommended instrument to detect caries in ICDAS assessment

A. No 23 explorer
B. CPITN probe
C. JW 17explorer
D. DG 16 explorer

Answer: B

International Caries Detection and Assessment System (ICDAS) is a new paradigm for the measurement of dental caries, which was developed from the systematic reviews of literature on the clinical caries detection system and other sources. The ICDAS I was developed in 2002 and was later modified to ICDAS II in 2005. The ICDAS measures surface changes and possible histological depth of the carious lesions depending on surface characteristics. Examination of clean and dry teeth is the primary requirement for applying the ICDAS system. The instrument used is a ball ended explorer to remove any plaque or food debris.

From code 3 onwards CPI/WHO probe is used to confirm the findings.

10. Axiopulpal depth of proximal box in Amalgam class II preparation

A. 2-2.2 mm
B. .2-.8 mm
C. .5 to 1 mm
D. 1-1.5 mm

Answer B) .2- .8 mm