1.Night guard bleaching refers to

A. Laser activated bleaching
B. Dentist prescribed home applied technique
C. Thermo bleaching
D. Photobleaching

2.Vital bleaching causes

A. Internal resorption
B. Cervical resorption
C. External resorption
D. Periapical periodontitis

3.Tooth discoloration is due to

A.Acute pulpal Abscess
B. pulpal hyperemia
C. Pulpal death
D. None of the above

4.In The Walking bleach technique

A. It uses a heat treatment
B. It requires the patient to report in 24 hours
C. Can be done with 35 percentage hydrogen peroxide
D. It uses a mixture of sodium perborate and hydrogen peroxide

5.The most common consequences of bleaching nonvital teeth is

A. Discoloration
B. Cervical resorption
C. Apical periodontitis
D. Root resorption

6.Which of the following is used to bleach a discoloured endodontically treated tooth

A. Ether
B. Chloroform
C. Superoxol
D. Sodium hypo chlorite

7.discoloration of teeth results from

A. Decomposition of the pulp
B. filling materials
C. Haemorrhage following pulp extraction
D. All of the above

8. bleaching is indicated in which of the following clinical situations

A. dentin discoloration
B. teeth with discoloured composites
C. tooth discoloration due to caries
D. Teeth with superficial discolorations

9.Discoloration of tooth in Tetra cycline therapy Is because of formation of

A. Calcium orthophosphate
B. Dicalcium phosphate dihydrate
C. Calcium oxide
D. Tetra calcium phosphate

10.The common sequels Following bleaching nonvital teeth are

A. Ankylosis
B. Periodontal pathology
C. External cervical resorption
D. Reinfection

Answer with explanation

1. B

2. D

3. C pulpal death is most common cause of tooth discoloration.There is breakdown of haemoglobin in to various pigments Like hemin, hemosiderin, hematoprphyrin. Hydrogen sulphide produced by bacteria combines with these pigments and darkens the tooth.

4. D

5. B. Cervical resorption is a common consequences of breaching of nonvital teeth whereas apical periodontitis is a common sequel Off bleaching of vital teeth. the possibility of cervical resorption can be reduced by sealing the root canal orrifice with Cavit to Prevent percolation of bleaching agent or by keeping a paste of calcium hydroxide and sterile water in the pulp chamber.

6. C

7. D

8. A. Bleaching agents like hydrogen peroxide can penetrate dentin And release oxygen that breaks down the double bond of organic and inorganic compounds inside the tubule.Option b, c and d Are Contra indications of bleaching.

9. A Tetracyclin causes discoloration during formation Period.It reacts with calcium to form calcium ortho phosphate complex. The minimum amount required to produce discoloration is 21 milligramme per kg per body weight.

10. C