PGCEE MDS 2022: Preventive and therapeutic measures for dealing with the periodontal problems during fixed appliance therapy

 # 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. 

PGCEE MDS 2022: The common site for necrotizing sialometaplasia:

 # 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. 

PGCEE MDS 2022: The preferred gingival finish line for veneer is:

 # 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.

PGCEE MDS 2022: Vasoconstrictor in local anesthetic (LA) solution:

 # 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 it remains for longer periods, thereby increasing (in some cases significantly, in others minimally) the duration of action of most local anesthetics.

5. Vasoconstrictors decrease bleeding at the site of administration; therefore they are useful when increased bleeding is anticipated (e.g., during a surgical procedure).