Dentosphere : World of Dentistry

 # Which of the following are typical and acceptable preventive and therapeutic measures for dealing with the periodontal problems during fixed appliance therapy? a) Elimination of gingivitis prior to placing orthodontic appliances b) Home care instruction regarding the use of the toothbrush and water pik during orthodontic treatment c) Megavitamin therapy d) Scaling and curettage immediately after appliance removal The correct answer is A. Elimination of gingivitis prior to placing orthodontic appliances Maintaining oral hygiene becomes more challenging once the fixed orthodontic brackets are placed. Pre-existing gingivitis should be treated and eliminated before placing the brackets. 

 # The common site for necrotizing sialometaplasia: a) cheeks  b) dorsum of tongue c) palate  d) gingival The correct answer is C. Palate. Necrotising sialometaplasia is a benign, inflammatory reaction of salivary gland that mimics a salivary gland malignancy. Etiology is mostly due to local ischemia. Most common intraoral site is palate followed by buccal mucosa and the type of necrosis is coagulative necrosis. Similar type of lesions in skin are called as syringometaplasia. 

 # The preferred gingival finish line for veneer is: a) Shoulder  b) Chamfer c) Shoulder with bevel  d) Radial shoulder The correct answer is B. Chamfer. The preferred gingival finish line for veneer metal restorations is the chamfer. This finish line has been shown experimentally to exhibit the least stress, so the cement underlying it will have less likelihood of failure. It can be cut with the tip of a round-end diamond while the axial reduction is being done with the side of that instrument.

 # Vasoconstrictor in local anesthetic (LA) solution: a) Reduces toxic effects of LA solution.  b) Decreases depth & duration of LA.  c) Increases bleeding.  d) Has no effect on efficacy of LA solution. The correct answer is A. Reduces toxic effects of LA solution. Vasoconstrictors are drugs that constrict blood vessels and thereby control tissue perfusion. They are added to local anesthetic solutions to oppose the inherent vasodilatory actions of the local anesthetics. Vasoconstrictors are important additions to a local anesthetic solution for the following reasons: 1. By constricting blood vessels, vasoconstrictors decrease blood flow (perfusion) to the site of drug administration. 2. Absorption of the local anesthetic into the cardiovascular system is slowed, resulting in lower anesthetic blood levels. 3. Local anesthetic blood levels are lowered, thereby decreasing the risk of local anesthetic toxicity. 4. More local anesthetic enters into the nerve, where i...

 # In winter's WAR line, Amber line represents the: a) Relative depth of the III molar b) Point of application of the elevator c) Bone level covering the impacted tooth d) Axial inclination of the impacted tooth relative to Second molar The correct answer is C. Bone level covering the impacted tooth. Winter's lines include 3 imaginary lines that are drawn on the radiographs. • White line • Amber line • Red line White Line: It is drawn touching the occlusal surfaces of 1st and 2nd molars and is extended posteriorly over the 3rd molar region. It indicates the difference in occlusal level of 2nd and 3rd molars. Amber Line: It is drawn from the crest of interdental bone between 1st and 2nd molars and extends posteriorly distal to 3rd molar or to the ascending ramus. It indicates the amount of alveolar bone covering the impacted tooth and the portion of tooth that is not covered by the bone. Red line: It is drawn perpendicular from the amber line to an imaginary point of application...

 # Gracey’s curette no 15/16 is used for: A. Anterior teeth B. Premolars C. Mesial surface of posterior teeth D. Distal surface of posterior teeth The correct answer is C. Mesial surface of posterior teeth.  Double-ended Gracey curettes are paired in the following manner: Gracey #1-2 and 3-4: Anterior teeth Gracey #5-6: Anterior teeth and premolars Gracey #7-8 and 9-10: Posterior teeth: facial and lingual Gracey #11-12: Posterior teeth: mesial Gracey #13-14: Posterior teeth: distal  Recent additions to the Gracey curette set have been the Gracey #15-16 and 17-18. The Gracey #15-16 is a modification of the standard #11-12 and is designed for the mesial surfaces of posterior teeth. It consists of a Gracey #11-12 blade combined with the more acutely angled #13-14 shank. When the clinician is using an intraoral finger rest, it is often difficult to position the lower shank of the Gracey #11-12 so that it is parallel with the mesial surfaces of the posterior teeth, especially ...

 # Jug handle view is another name for: a. occipitomental view  b. submentovertex view  c. lateral cephalogram  d. lateral oblique view The correct answer is B. Submentovertex view. Submentovertex projection or jug handle view:   The image receptor is positioned parallel to the patient’s transverse plane and perpendicular to the midsagittal and coronal planes. To achieve this position, the patient’s neck is extended as far backward as possible, with the canthomeatal line forming a 10-degree angle with the image receptor.