(141-150) 141. Gutta percha can be effectively sterilized by:



1.       Hot salt sterilizer.
2.       Autoclaving.
3.       Chemical solutions.
4.       Dry heat.

142.        The most important aspect of the emergency treatment for an acute apical abscess is:

1.       Produce sedation.
2.       Establish drainage.
3.       Maintain obturations.
4.       Adjust the occlusion.

143.        A polyp may arise in connection with;

1.       Chronic open pulpitis.
2.       Pulp necrosis.
3.       Acute pulpitis.
4.       Chronic periapical region.

144.        Which of the following is used to bleach a discolored, endodontically treated tooth?

1.       Ether.
2.       Chloroform.
3.       Superoxol.
4.       Sodium hypochlorite.

145.        The primary function of access opening is to:

1.       Facilitate access for irrigation.
2.       Facilitate canal medication.
3.       Aid in locating root canal orifice.
4.       Provide straight-line access to the apex.

146.        A cold test localizes:

1.       Pain of pulpal origin.
2.       Pulp necrosis.
3.       Periodontal pain.
4.       Referred pain.

147.        Calcification of pulp:

1.       It is in response to aging.
2.       Does not related to periodontal conditions.
3.       Precedes internal resorption.
4.       Indicates the presence of an additional canal.

148.        Electric pulp testing may not be performed on patients who have:

1.       Hip implants.
2.       Pace maker.
3.       Dental implants.
4.       Prosthetic eye.

149.        For root canal therapy of maxillary canines (distal caries), the isolation done is:

1.       1st premolar to the opposite lateral incisor.
2.       1st molar to opposite lateral incisor.
3.       Adjacent two teeth of both the sides.
4.       Not required, only the tooth to be treated.

150.        Avulsed tooth may be stored in saliva for upto:

1.       2 hours.
2.       3 hours.
3.       4 hours.
4.       Indefinitely.

141         3      Grossman (11)-140
142         2      Grossman (11)-20,21
143         1      Grossman (11)-70
144         3      Grossman (11)-272
145         4      Grossman (11)-179
146         1      Grossman (11)-14
147         1      Grossman (11)-48
148         2     
149         4      Studervant (4)-450
150         1      Grossman (11)-332

Ans. 141. C. Chemical solutions.
               (Ref: Grossman-11th Ed/ Pg 140)
  Gutta-percha cones may be kept sterile in screw capped vials containing alcohol.
  To sterilize a Gutta-percha cone freshly removed from the manufacturer’s box, one should immerse it in 5.2% Sodium Hypochlorite solution for One minute.
  The cone is then rinsed with Hydrogen peroxide and dried between two layers of sterile gauze.
  It has been demonstrated that Sodium Hypochlorite is more effective than Sporicidin and 7 times as effective as activated dialdehyde for sterilizing Gutta percha.
  Also remember that Silver cones are sterilized by slowly passing them back and forth through a Bunsen burner flame, 3 or 4 times or by immersing it in a hot salt sterilizer for 5 seconds- a temperature of 425 to 475 F. The special kind of plier used to insert or remove silver cones is called as Stieglitz pliers or forceps.
Ans. 142. B. Establish drainage.
               (Ref: Grossman-11th Ed/ Pg 20, 21)
  To relieve this (of acute alveolar abscess) constant pain, one should establish drainage through the root canal preferably, and through the soft tissue and bone, if necessary- Pg 20.
  “The value of test cavity in treating teeth with acute alveolar abscess is two fold. First, it tests for any remaining vital pulp that could require anesthesia and second, it initiates emergency therapy quickly, because the pulp chamber can be penetrated painlessly without delay, waiting for anesthesia to take effect.
  Leaving the tooth open for drainage, reduces the possibility of continued pain and swelling.
Ans. 143. A. Chronic open pulpitis
               (Ref: Grossman-11th Ed/ Pg 70)
Chronic hyperplastic pulpitis or pulp polyp is a productive pulpal inflammation due to extensive carious exposure of a young pulp. It is characterized by the development of granulation tissue”
The causes of pulp polyp include:
1.   Slow, progressive carious exposure of the pulp is the cause for development of hyperplastic pulpitis. A large open cavity, a young resistant pulp and chronic low grade stimulation are necessary.
2.   Mechanical irritation from chewing and bacterial infection can often provide the desired stimulus.
Ans. 144. C. Superoxol.
               (Ref: Grossman-11th Ed/ Pg 272)
  Superoxol is 30% solution of Hydrogen peroxide by weight and 100% by volume in pure distilled water.
  It is stored in a light proof, amber colored bottle, away from heat.
  In a refrigerated, sealed container it can be stored for approximately 3 to 4 months.
  It has an ischaemic effect on the skin and the mucous membrane that resembles a chemical burn.
  It is especially painful, if it comes in contact with the nail bed or the soft tissues under the finger nail.
  The amount needed for the bleaching operation is about 1 to 2 ml, dispensed in a clean dappendish.
  For bleaching endodontically treated teeth, the solution can be used alone or mixed with sodium perborate into a paste- a technique called as Walking Bleach.
  When placed into the pulp chamber the mixture oxidizes slowly and discolors the stain over a period of time.
Ans. 145. D. Provide straight line access to the apex.
               (Ref: Grossman-11th Ed/ Pg 179)
Endodontic treatment can be divided into three main phases:
1.   Biomechanical preparation of the root canal
2.   Disinfection of the canal
3.   Obturation of the prepared canal.
               The initial step for cleaning and shaping the root canal is proper access to the chamber that leads to a straight line penetration of the root canal orifices.
               The next step is exploration of the canal, extirpation of the remaining pulpal tissue or gross debridement of necrotic pulp tissue and the verification of the instrument length.
               This step is followed by proper instrumentation, copious irrigation and disinfection of the root canal.
               Obturation usually completes the procedure.
      The principle aim of access opening is thus to obtain a straight line access to the apex. 
Ans. 146. C. Pain of pulpal origin
               (Ref: Grossman-11th Ed/ Pg 14)
THERMAL TESTING
  A response to cold indicates a vital pulp regardless of whether the pulp is normal or abnormal.
  A heat test is not a test of pulpal vitality. An abnormal response to heat generally indicates the presence of a pulpal or a peri-apical pathology requiring endodontic treatment.
  When a reaction to the cold test occurs the patient can easily point out to the painful tooth.
  The heat response when described by the patient can be localized or diffuse and at times referred to different sites.
  The preferred temperature for heat testing is 65.5C and that for the cold test is 5C.
  The temperature of Dry ice or solid Carbon-di-oxide is around -78C. The major disadvantage of its use is that infarction lines may result.
Ans. 147. A. It is in response to aging.
               (Ref: Grossman-11th Ed/ Pg 48)
The text states that “the origin of pulp calcification is controversial. The occurrence of this phenomenon in both old and young pulps prevents the exposition of a reasonable theory”.
Mineralization of Pulp
  Although their presence has been related to age and diseases, the calcifications also occur in young, healthy pulps.
  They are present as nodules called as denticles.
  Denticles predominate in the pulp chamber where as diffuse calcifications are predominantly found in the root canals.
  Denticles can be true or false.
  True denticles are usually found near the apex of the root canal.
  False denticles are found free in pulp tissue attached to the dentinal walls or embedded in the dentin.
  Calcifications in the root canals are usually not seen radiographically but may be detected during the exploration of the canal.
Ans. 148. B. Pace maker.
               (Ref: Operative Dentistry-Vimal Sikri-1st Ed/ Pg 64)
  If the patient has a medical history of a Cardiac pacemaker, electric pulp testing is contraindicated as it may interfere with the electrical activity of the pacemaker.
  EPT uses electrical excitation to stimulate the A-delta nociceptor sensory fibres within the pulp.
  Teeth that temporarily or permanently lose their sensory function, as after trauma or Orthognathic surgery are generally non-responsive to EPT.
  False positive results may be obtained in necrotic pulps.
  False negative response may occur with pre-medications, alcohol, immature teeth, trauma, poor contact with tooth, inadequate media and partial necrosis.
  In initial few days after an injury, a temporary paresthesia of the nerves may occur and make them unresponsive to testing. If the pulp retains its vitality, it will respond within normal limits after 30 to 60 days.
Ans. 149. D. Not required, only the tooth to be treated.
               (Ref: Sturdevant-4th Ed/ Pg 450)
Isolation of a minimum of three teeth is recommended except when endodontic therapy is indicated, and in that case only the tooth to be treated is isolated”.
Remember
  When operating on the incisors and the mesial surfaces of the canine, isolate from 1st premolar to the 1st premolar.
  When operating on a canine, it is preferred to isolate from the first molar to the opposite lateral incisor.
  To treat class V lesions on the canine, isolate posteriorly to include the first molar to provide access for the cervical retainer placement on the canine.
  When operating on the posterior teeth, it is beneficial to isolate anteriorly to include the lateral incisors on the opposite side.
  When operating on the premolars punch holes to include two teeth distally and extend anteriorly to include the opposite lateral incisor.
  When a cervical retainer is to be applied to isolate a class V lesion, a heavier dam is usually recommended for better tissue retraction, and the hole for tooth should be punched slightly facial to the arch form to compensate for the extension of the dam in the cervical area.
  When a thinner rubber dam is used, smaller holes must be punched to achieve an adequate seal around the teeth because the thinner dam has greater elasticity.
Ans. 150. A. 2 hours.
               (Ref: Grossman-11th Ed/ Pg 332)
“Blomtof has shown that milk preserves the vitality of periodontal ligament longer than saliva, 6 hours versus 2 hours respectively
  Once the tooth has been avulsed, effort should be made to preserve the vitality of the PDL.
  The avulsed tooth should be immediately rinsed in water and replanted into the socket by the patient.
  The best storage medium for storage of the avulsed tooth, for maintaining the vitality of the PDL is the tooth socket.
  The second order of preference is to rinse the tooth in water and submerge it in a container of milk, with the patient instructed to report to the dentist immediately with the tooth.
  The next option is to place the tooth in the buccal vestibule.
  The least preferable method is to rinse the tooth and place it in a cup of water and have it replanted by the dentist immediately.
           Another preferable medium is HBSS- Hanks Balanced Salt Solution, which consists of NaCl, KCl and glucose. 
 


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