Dentosphere : World of Dentistry

# Dose adjustment of all of the  following drugs will be required in a patient with severe liver cirrhosis EXCEPT: a) Lorazepam b) Theophylline c) Paracetamol d) Metronidazole The correct answer is A. Lorazepam. PHARMACOKINETICS Most of the BZDS are metabolized in the liver to produce active products (thus long duration of action). Active metabolites may result in cumulative effects. After metabolism, these are conjugated and are excreted via kidney. Estazolam, lorazepam, oxazepam, temazepam and triazolam are directly conjugated without metabolism to active products. These drugs are thus short-acting and do not accumulate on repeated administration. Further these drugs can be safely administered in liver failure and in elderly because these are conjugated directly without undergoing metabolism in the liver. (Mnemonics: @  TO-LET ; Short-acting drugs are T riazolam, O xazepam, L orazepam, E stazolam and T emazepam,). Compounds with shorter half life are...

# 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) 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) 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.