Dentosphere : World of Dentistry

# 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 Reply Forward

# 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) 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.

# 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 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 aff...

# In lead poisoning, gingival discoloration presents as: A. Blue black line B. Yellow line C. Grayish black line D. Steel gray line # Dilaceration occurs due to: A. Trauma to the tooth germ during root development B. Abnormal displacement of the tooth germ during root development C. Abnormal displacement of enamel epithelium during tooth development D. Abnormal displacement of ameloblasts during tooth development

CLICK HERE TO REVEAL ALL ANSWERS AFTER YOU HAVE MARKED ALL YOUR ANSWERS IN A SEPARATE PAPER AND CHECK YOUR SCORE. # Which one of the following is a junction of frontal,parietal, temporal and greater wing of sphenoid bone? A. Pterion B. Lambda C. Vertex D. Inion # A non synovial joint with dense connective tissue between two bony surfaces is termed as: A. Synchondrosis B. Syndesmosis C. Symphysis D. Suture