The most common cell found in healthy periodontal ligament is:

 # The most common cell found in healthy periodontal ligament is:

A. Neutrophil

B. Fibroblast

C. Epithelial cell

D. Osteoblast

The correct answer is B. Fibroblast.

Connective tissue cells include fibroblasts, cementoblasts, and osteoblasts. Fibroblasts are the most common cells in the periodontal ligament; they appear as ovoid or elongated cells oriented along the principal fibers, and they exhibit pseudopodia-like processes. These cells synthesize collagen and possess the capacity to phagocytose “old” collagen fibers and degrade them via enzyme hydrolysis.

Thus, collagen turnover appears to be regulated by fibroblasts in a process of intracellular degradation of collagen that does not involve the action of collagenase.

Reference: Carranza's Clinical Periodontology, 12th Edition, Page no: 25

CLICK HERE FOR MORE MCQs

Listerine is contraindicated in patients taking:

 # Listerine is contraindicated in patients taking:

A. Phenytoin

B. Cyclosporin

C. Nifedipine

D. Disulfiram

The correct answer is D. Disulfiram.

Listerine antiseptic and its generic counterparts are approved by the ADA Council on Dental Therapeutics to help prevent and reduce supragingival plaque and gingivitis. The active ingredients

in Listerine are methyl salicylate and three essential oils (eucalyptol, thymol, and menthol). Listerine has been shown to be effective in reducing plaque and gingivitis compared with placebo rinses in young healthy adults. Listerine may exacerbate xerostomia because of its high alcohol content, ranging from 21.6% to 26.9%. Listerine is generally contraindicated in patients under treatment for alcoholism

who take Antabuse (disulfiram). Listerine may benefit patients who do not tolerate the taste or staining of chlorhexidine and who prefer OTC medicaments that are less expensive and easier to obtain.

Reference: Carranza's Clinical Periodontology, 12th Edition, Page no: 450

CLICK HERE FOR MORE MCQs

Only antibiotic in periodontal therapy to which all strains of A. actinomycetemcomitans are susceptible:

 # The only antibiotic in periodontal therapy to which all strains of A. actinomycetemcomitans are susceptible:

A. Azithromycin

B. Ciprofloxacin

C. Cvefidipine

D. Metronidazole

The correct answer is B. Ciprofloxacin.

Ciprofloxacin

Pharmacology: Ciprofloxacin is a quinolone that is active against gram-negative rods, including all facultative and some anaerobic putative periodontal pathogens.

Clinical Use: Because it demonstrates a minimal effect on Streptococcus species, which are associated with periodontal health, ciprofloxacin therapy may facilitate the establishment of a microflora that is associated with periodontal health. At present, ciprofloxacin is the only antibiotic in periodontal therapy to which all strains of A. actinomycetemcomitans are susceptible. It has also been used in combination with metronidazole.

Reference: Carranza's Clinical Periodontology, 12th Edition, Page no: 519

CLICK HERE FOR MORE MCQs

Most aggressive bacteria penetrating connective tissue and resulting in bone destruction

 # Which of the following contains most aggressive bacteria penetrating connective tissue and resulting in bone destruction?

A. Subgingival unattached plaque

B. Subgingival tooth attached plaque

C. Subgingival attached plaque

D. Supragingival plaque

The correct answer is A. Subgingival unattached plaque.

The total width of the plaque-free zone varies according to the type of tooth (i.e., it is wider in the molars than in the incisors) and the depth of the pocket (i.e., it is narrower in deeper pockets). It is important to remember that the term plaque-free zone refers only to attached plaque, because unattached plaque contains a variety of gram-positive and gram-negative morphotypes, including cocci, rods, filaments, fusiforms, and spirochetes. The most apical zone contains predominantly gram-negative rods and cocci.

Reference: Carranza's Clinical Periodontology, 12th Edition, Page no: 285.

CLICK HERE FOR MORE MCQs 

The predominant immunoglobulin in gingival fluid is:

 # The predominant immunoglobulin in gingival fluid is:

A. IgA

B. IgG

C. IgM

D. IgE

The correct answer is B. IgG.

High levels of antibodies appear in GCF (in addition to those in the circulation), and these are produced locally by plasma cells in periodontal tissues. Antibodies to periodontal pathogens are primarily IgG, with few IgM or IgA types produced.

Reference: Carranza's Clinical Periodontology, 12th Edition, Page no: 97

CLICK HERE FOR MORE MCQs

Following are the examples of indirect retainers EXCEPT:

 # Following are the examples of indirect retainers except:

A. Occlusal rest

B. Auxillary occlusal rest

C. Canine rest

D. Continuous bar retainers and linguoplates

The correct answer is A. Occlusal rest.

Continuous clasp: “A metal bar usually resting on the lingual surface of teeth to aid in their

stabilization and to act as an indirect retainer”-GPT.

Canine rest

• If the mesial marginal ridge of the first premolar is close to the fulcrum line, canine rest is used.

• This design can be modified by placing the minor connector anterior to the canine. The minor connector hooks back into the cingular rest seat. This increases the efficacy of the indirect retainer (due to increase in distance from the fulcrum line).

Types of Indirect Retainers

The most commonly used type of indirect retainer is a rest connected to a minor connector. In some cases indirect retention is obtained without a rest.

Types:

1. Auxiliary occlusal rest

2. Canine extension from the occlusal rest

3. Canine rest

4. Continuous bar retainers and linguoplates

5. Modification areas

6. Rugae support

7. Direct indirect retention

8. Indirect retention from major connectors

Reference: Nallaswamy, 2nd Edition, Page 375

CLICK HERE FOR MORE MCQs

Main advantage of the palatal plate major connector is:

 # Main advantage of the palatal plate major connector is:

A. Thick metal plate

B. Thin metal plate

C. Surface irregularity of plate

D. Corrugated plate

The correct answer is D>B. 

Advantages:

• Intimate contact with the palatal tissues over a large area provides good retention due to the presence of interfacial surface tension.

• Provides good vertical support.

• Numerous surface corrugations due to very thin metal provide a very natural feel.

Reference: Nallaswamy, 2nd Edition, Page No 331

CLICK HERE FOR MORE MCQs