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The biggest advantage of pulp revascularization in endodontics is:

 # The biggest advantage of pulp revascularization in endodontics is:
A. Achieving continued root development
B. No additional material such as TCP or MTA is required
C. No obturation is needed
D. After control of infection, it can be completed in a single visit


The correct answer is A. Achieving continued root development.

Revascularization is a new treatment method for immature (open apex) necrotic permanent teeth. This technique allows the growth of root even when the pulp is necrotic. This helps in strengthening and avoiding damage to the remaining thin and fragile walls of the immature apex. The main aim of this technique is stimulating the residual apical pulp stem cells which are able to survive due to the abundant blood supply in the open apex cases.

Revascularization procedure aids in:
- Stimulation of odontoblasts or undifferentiated mesenchymal cells at the periapex
- Deposition of the calcific material at the apex as well as lateral dentinal walls
- Normal maturation of the entire root

MTA can be dissolved by adjunct solution of:

 # Set white MTA can be dissolved by adjunct solution of:
A. Carbonic acid
B. Normal saline
C. Sodium hypochlorite
D. Hydrogen peroxide



The correct answer is A. Carbonic acid. 

Carbonic acid can be effectively used as an adjunct to set white MTA even after 21 days.

Indications for Prenatal Diagnosis by lnvasive Testing

 Principal Indications for Prenatal Diagnosis by lnvasive Testing

- Advanced maternal age (greater than 35 years)
- Previous child with de novo chromosomal aneuploidy
- Presence of structural chromosome abnormality in one of the parents
- Family history of a genetic disorder that may be diagnosed or ruled out by biochemical or DNA analysis
- Family history of an X-linked disorder for which there is no specific prenatal diagnostic test
- Risk of a neural tube defect (first degree relatives of patients with neural tube defects)
- Fetal abnormalities are suspected on Maternal serum screening and ultrasound examination 


Which of the following is not a sporicidal disinfectant?

 # Which of the following is not a sporicidal disinfectant?
A. Glutaraldehyde
B. Formaldehyde
C. Ethylene oxide
D. Benzalkonium chloride



The correct answer is D. Benzalkonium chloride.

Sporicidal agents are: 
E- Ethylene oxide
F- Formaldehyde
G- Glutaraldehyde
H- Halogens 

Benzalkonium chloride is quartenary ammonium antiseptic which is not sporicidal. Only aldehydes, halogens and ethylene oxide are sporicidal disinfectants. 

Formaldehyde is active against the amino group in the protein molecule. In aqueous solutions, it is marked bactericidal, sporicidal and virucidal. It is used to preserve anatomical specimens and for destroying anthrax spores in hair and wool. 10% formalin containing 0.5% sodium tetraborate is used to sterilize clean metal instruments. 

Glutaraldehyde has an action similar to that of formaldehyde. It is especially effective against the tubercle bacilli, fungi and viruses. 

Ethylene oxide is a colorless liquid with a boiling point of 10.7 degree centigrade and highly penetrating at normal temperature and pressure. Therefore, ethylene oxide can be used for sterilization of heat sensitive equipments like heart lung machine, respirators and dental equipment. 

Which of the following cannot be reliably used for handwashing?

# Which of the following cannot be reliably used for handwashing?
A. Lysol
B. Cresol
C. Isopropyl alcohol
D. Chlorhexidine



The correct answer is A. Lysol.

Lysol is a phenolic compound derived from coal tar and is highly toxic to humans. It is recommended for disinfection of surfaces in hospital. 

These can be reliably used for handwashing: 
- Chlorhexidine
- Alcohols (isopropyl alcohol, ethyl alcohol)
- Iodine
- Cresol
- Chloroxylenol (dettol)
- Hexachlorophane
- Tincture of iodine


Pseudomonal infection should not be cleaned by:

 # Pseudomonal infection should not be cleaned by:
A. Dettol
B. Hypochlorite
C. Chlorine
D. Betadine



The correct answer is A. Dettol.

Pseudomonas aeruginosa is heat-labile bacteria, readily killed at 55 degrees celcius in 1 hour. It is also highly susceptible to acid, silver salts, 2% alkaline glutaraldehyde, and disinfectants. 

Due to its sensitivity to silver salts, silver sulphonamide compounds have been used as topical cream in burns. However, Pseudomonas aeruginosa is very strongly resistant to common antiseptics and disinfectants, such as chloroxylenol (dettol), hexachlorophane and quartenary ammonium compounds. Indeed, selective media have been devised for isolation of Pseudomonas aeruginosa incorporating dettol or cetrimide. 

Extractions can be done in ANUG patients after:

 # Extractions can be done in ANUG patients after:
A. At first appointment
B. 4 weeks
C. 4 months
D. 1 week


The correct answer is B. 4 weeks.

Unless an emergency exists, extractions and periodontal surgeries are postponed until the patient has been symptom free for a period of 4 weeks to minimize the likelihood of exacerbation.