Dentosphere : World of Dentistry

 # High content of cholesterol is present in: A. Coconut oil B. Egg yolk C. Hydrogenated fat D. Ghee (Unsaturated) The correct answer is B. Egg yolk. Cholesterol is exclusively found in animals and is the most abundant animal sterol. It is a major component of cell membranes and lipoproteins. Elevation of serum cholesterol beyond 200 mg/dL increases the risk of atherosclerosis and coronary heart diseases.  CLICK HERE FOR MORE MCQs

 # The first heart sound is loud in all of the following EXCEPT:  A. Mitral stenosis B. Short PR interval C. Tachycardia D. Mitral valve calcification The correct answer is D. Mitral valve calcification. The intensity of the first sound is primarily related to the position of the atrioventricular valves at the onset of ventricular systole. The first sound is usually louder in subjects with a short PQ interval than in those with a long PQ interval. Loud first heart sound: is seen in mitral stenosis, left atrial myxoma, conditions that increase myocardial contractility, including hyperadrenergic states (e.g. exercise, anxiety, anemia, fever, pregnancy, and thyrotoxicosis) and in patients with thin chest walls.  A loud first heart sound is a hallmark of hemodynamically significant mitral stenosis. Mobile but stiff mitral leaflets produce a loud S1 unless the leaflets are heavily calcified. The main reason for the increase in the intensity of S1 in these conditions is the inc...

 # Instrument of choice for biomechanical preparation in fine root canals of double curved canals is:  A. H file B. K flex file C. Unifile D. Reamer The correct answer is A. H file. H file or S file is also used for finishing coronal third of root canal. It is also used for biomechanical preparation of fine canals. Used for flaring the fine and double curved root canals and is used in McSpadden compaction technique. CLICK HERE FOR MORE MCQs

 # Triangular instruments while cutting canals will have to rotate _______ to complete one turn. A. ¼ turn B. ½ turn C. 1/3 turn D. Full turn The correct answer is C. 1/3 turn. The triangular shaft requires a one-third (120 degrees) rotation of the instrument to complete a cutting circle of the root. For cutting action in a canal, a traingular shaft instrument requires 1/3 turn. These cutting points are at 120 degrees to each other and they move simultaneously. So, a 1/3 turn or 120 degree turn will bring about a complete cuttting circle.  CLICK HERE FOR MORE MCQs

 # The best instrument for cutting dentin is: A. Reamer B. File C. Broach D. Explorer The correct answer is A. Reamer. Reamer contains sharp cutting edges that are spaced further apart than the file and therefore it is engaged in dentin more rapidly and readily facilitates dentin removal. CLICK HERE FOR MORE MCQs

 # Chief cells are located in gastric gland in the region?  A. Fundus  B. Isthmus C. Neck D. Equally spread The correct answer is A. Fundus. Gastric gland is composed of three types of cells: A. Mucous neck cells - secrete mainly mucus but also some pepsinogen B. Peptic/chief cells - Secrete pepsinogen in body and fundus C. Parietal/Oxyntic cells- Secrete hydrochloric acid and intrinsic factor CLICK HERE FOR MORE MCQs