# Of the following local anesthetics, which has intrinsic vasoconstrictive action? (MAN -97)

# Of the following local anesthetics, which has intrinsic vasoconstrictive action? (MAN -97)
a) Cocaine
b) Procaine
c) Xylocaine
d) Bupivacaine

The correct answer is : A. Cocaine

All local anaesthetics except cocaine are synthetic compounds and they are vasodilating in nature. Cocaine is a natural local anaesthetic agent and causes local vasoconstriction.

 (Cocaine increases the vasoconstrictive action of adrenaline. If LA with adrenaline is given risk of death is more in cocaine abusers. So they are known as  'walking time bombs.'

Which of the following is the preferred local anesthetic technique for hemophilics? (MAN -01)

# Which of the following is the preferred local anesthetic technique for hemophilics? (MAN -01)
a) Nerve block
b) Supraperiosteal
c) Intraligamentary
d) Field block

The correct answer is C. Intraligamentary.

 In hemophilics to avoid complications,  Intraligamentary  (an intraosseous technique) method of local infiltration technique is preferred. In this technique, the solution is deposited in depth of gingival sulcus. The needle should be inserted apically into the bone until resistance is met.

# Which of the following may least be used as an abutment: (PGI -2K)

# Which of the following may least be used as an abutment: (PGI -2K)
a) Tooth with minimum crown
b) Tooth with short tapered crown and conical roots
c) Rotated and tipped tooth
d) Pulp treated tooth

The correct answer is: B. b) Tooth with short tapered crown and conical roots

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# Epitheloid cells are seen in all of the following except (MAN -02):

# Epitheloid cells are seen in all of the following except (MAN -02):
a) Tuberculosis
b) Granulation tissue
c) Syphilis
d) Sarcoidosis

The correct answer is : B. Granulation Tissue

Epitheloid cells are a collection of modified macrophages present in granuloma. Granulomas occur in Tuberculosis, Leprosy, syphilis, Actinomycosis, Sarcoidosis, etc.

# The wetting of an adherent surface by an adhesive is related to: (AIPG-01)

# The wetting of an adherent surface by an adhesive is related to:
(AIPG-01)
A. Surface texture of the adherent
B. Surface energy of the adherent
C. Nature of the adherent that is crystalline or amorphous
D. Surface tension of the adherent

The correct answer is B. Surface energy of the adherent.

The property of wetting and adhesions are directly related to surface energy of adhesives. Substances with low surface energy like teflon are often used to prevent the adhesion of films to a surface. Metals because of their high surface energy, interact vigorouslywith liquid adhesives.

The surface energy of many restorative materials is higher when compared to that of tooth. So, there is greater tendency for the surface and margins of restorations to accumulate debris. This property will explain the relatively high incidence of marginal caries seen around dental restorations.

What is Proportional Limit?

# The proportional limit is defined as:
A. The maximum stress in a structure
B. The minimum force required to cause a structure to break
C. The maximum stress that can be induced without permanent deformation
D. The maximum elongation under tension that
 can be measured before failure

The correct answer is C. The maximum stress that can be induced without permanent deformation.

Stresses above proportional limit cause plastic deformation. This stress is called yield strength or proof stress. It  is the greatest stress, produced in a material such that stress is directly proportional to the strain. 

Phillip's Science of Dental Materials, 12th ed. Page no 57.

Most Common reason for removal of Impacted Mandibular third molars:

# Most common reason for the removal of impacted mandibular third molars is:
 A. Referred pain
 B. Recurrent pericoronitis
 C. Chronic periodontal disease
 D. Orthodontic treatment


The correct answer is B. Recurrent Pericoronitis

Pericoronitis is an inflammatory lesion occurring around the impacted or partially erupted tooth. An incomplete eruption of the tooth provides a large stagnation area for food debris under the gingival flap. This becomes infected easily and results in inflammation of the pericoronal flap. It exhibits chronic inflammation for a long period. If the debris and bacteria are deeply entrapped, an abscess may form which is called a pericoronal abscess. It is a mixed infection and various bacteria of the dental plaque (particularly anaerobes) play a significant role in the development of pericoronitis.

Clinical Features: The mandibular third molar is the commonly involved tooth. Pain and swelling of the pericoronal tissue around the affected tooth, difficulty in chewing, and difficulty in opening the mouth are the usual complaints. The patient may be mildly ill with fever, malaise, and regional lymphadenopathy.

Management: Entrapped food debris must be removed. When the upper tooth is involved, it should be grounded or extracted if it is malposed. Radiograph helps in assessing the position of the involved tooth. If impacted, the tooth must be removed. And if it is in a favorable position, surgical removal of the pericoronal flap is advocated after acute symptoms subside. The administration of antibiotics helps to relieve the symptoms and prevents the spread of infection to the adjacent tissue spaces.

Ref: Shafer's Textbook of Oral Pathology, 7E, Page: 400