1. Most cutting procedures with electrosurgery in the oral cavity are best accomplished with
A. fully filtered, fully rectified current
B. coagulation current
C. fully rectified current
D. partially rectified current
Answer C.) Fully rectified currents produce good cutting and adequate hemostasis
2. In the use of electrosurgery in the oral cavity, profound anesthesia is
A. usually needed
B. never needed
C. almost always needed
D. not needed for endodontically involved teeth
Answer C.) Profound anesthesia is needed because of the vital tissue which contains nerve ending. In addition, the electrode tip will stimulate the pulp much like a pulp-testing device.
3. Electrosurgery is
A. the same as electrosurgery
B. accomplished with a cold electrode and an electronic arc
C. performed by a heated electrode
D. accomplished with a hot electrode and an electronic arc
Answer B.) Heat is produced by the impedence of the tissue and not in the electrode. Arcing occurs in the tissue at the point of electrode contact.
4. A factor determining the setting for the cutting current is
A. room temperature
B. amount of anesthesia
C. size of the machine being used
D. tissue thickness
Answer D.) The setting for the cutting current is directly proportional of the thickness of the tissue. The ticker the tissue, the greater is the resistance to the passage of current. The nature, type, density and the amount of hydration all affect the resistance of tissue.
5. Electrosurgical preparation of the sulcus for impression taking
A. requires healthy gingival tissue
B. requires the use of coagulation current
C. eliminates the need for retraction cord
D. requires the need of retraction cord
Answer A.) Healthy gingival tissue is a prerequisite for any impression taking procedure, whether preceded by electrosurgical techniques or the use of gingival retraction impregnated cor. The level of healing is unpredictable in unhealthy tissue.
6. A too low setting of the control dial for cutting results in
A. fulguration
B. dessication
C. more damage to tissue
D. less damage to tissue
Answer C.) Too low a setting for cutting purposes with electrosurgical equipment result in more damage to the tissue because this reduces the impedence and the progress of the electrode through this tissue will be too slow. Greater heat will be produced on either side of the incision, which may result in necrosis.
7. Tissue adhering to the electrode
A. impedes the progress of the electrode through the tissue
B. is of little importance
C. requires the use of lower current settings
D. usually volatilizes before it becomes a problem
Answer A.) Tissue adhering to the electrode will impede the progress of the electrode through the tissue because the retained tissue tags will reduce impedence. This will result in heat build-up latreral to the incision which may cause necrosis.
8. The indifferent plate is used
A. primarily for fulguration
B. because it permits the use of higher currents
C. primarily for electrodessication
D. because it allows the use of lower currents
Answer D.) Although high frequency rediowaves do not require a circuit, the use of an indifferent plate allows more efficient return of energy to the source, thereby allowing the use of lower current settings which are less damaging.
9. The foot control should be
A. activated before cutting the tissue
B. activated upon touching the tissue for cutting
C. activated intermittently while cutting the tissue
D. activated only for fulguration
Answer A.) The foot control should be activated prior to cutting the tissue because of the initial surge of energy that is generated at the tip which will cause tissue damage and coagulation.
10. The crown-root ratio
A. can easily be increased in periodontally involved posterior teeth
B. should never be decreased in periodontally involved anterior teeth
C. can be decreased in periodontally involved anterior teeth
D. none of the above
Answer C.) The crown root ratio can be decreased in periodontally involved anterior teeth to reduce the mobility factor and diminish the load on the anterior teeth. Reducing the crown root ratio in periodontally involved posterior teeth can result in the reduction of the vertical dimension.
11. Decreasing the crown-root ratio in the posterior segment will
A. result in an increased vertical dimension
B. have no effect on facial height
C. decrease vertical dimension
D. none of the above
Answer C.) Shortening the crown to root ratio in the posterior segment can potentially decrease the primary holding or supporting cusps and result in a closed bite.
12. Hemisection means
A. the separation and removal of the roots of a tooth
B. separating the roots of a tooth
C. sectioning the roots of a tooth in half
D. sectioning both the root and the crown of a tooth
Answer . D.) Hemisection means dividing the tooth essentially in half, sectioning and removal of any part of a root or roots is usually referred to as root amputation.
13. A telescopic retainer is
A. a special type of overcastting for crowns
B. an additional casting underneath the crowns of a bridge
C. an undercasting for posterior abutments only
D. used primarily under partial denture abutments
Answer D.) Telescopic retainer is an additional casting underneath the crowns of a fixed bridge or a removal partial denture. It is usually constructed of gold alloy which is very thin in dimension. After the preliminary undercasting is made, impressions are taken to fabricate overcastting for a fixes bridege or a removable partial denture.
14. A major limitation to the use of the anterior teeth is
A. its added thickness
B. its cost
C. the length of treatment
D. esthetics
Answer A.) A major limitation in the use of telescopic retainer, especially in anterior teeth, is that it will provide additional thickness. Consequently, it is imperative that, in a construction of telescopic retainers, additional tooth structure is removed to provide space to accommodate both an undercasting and an overcastting.
15. To cement the telescopic retainer to the abutment tooth
A. a weaker cementing medium should be used than that for the overcase and retainer
B. a stronger cementing medium should be used than that for the overcase and retainer is advantageous
C. same type of cement is used as that for both overcase and telescope
D. none of the above
Answer B.) It is generally advisable to cement the undercasting directly to the abutment tooth with permanent cement. If this is not done the undercasting can, potentially, be dislodged. Other possible sequale marginal leakage, sensitivity, recurrent caries and loss of tooth vitality.
16. The use of floss under a ridge lap pontic
A. is an irritant when there is inflammation present
B. adequately removes plaque
C. improves the ridge tissue
D. seldom is necessary
Answer A.) The use of loss under a ridge lap pontic will cause irritation to the tissue whether there is existing inflammation or not. The floss under a ridge lap pontic would rest upon the buccal and lingual extension of the cervical portion of the pontic; consequently the use of floss would further insult the ridge tissue.
17. More important than the material used for a pontic is
A. the shape of the ridge
B. the position of abutment teeth
C. the design of the pontic
D. the number of the missing teeth
Answer C.) The design of the pontic is of utmost consideration in the fabrication of a fixed bridge because improper pontic design can result in chronic inflammation of the infrapontic space area which ultimately will involve the abutment teeth. Any material can be used for pontics provided that the modified ridge lap concept is employed, the surface of the pontic is highly polished and does not exert pressure on the residual ridge.
18. The buccal and lingual shunting mechanism of a pontic
A. can be narrower than that of the adjacent teeth
B. should conform to those of the adjacent teeth
C. can be disregarded in short span bridges
D. should be designed differently in the anterior segment as opposed to the posterior segment
Answer B.) The buccal lingual shunting mechanism of a pontic should conform to those of adjacent teeth to prevent food impactions at the abutments. Food impaction will result if the pontic has a narrower buccal/lingual dimension than the adjacent abutment teeth.
19. In cases where the shape of the ridge is grossly aberrant
A. compensate by the design of the pontic
B. don’t consider fixed prosthetics
C. consider the use if implants
D. consider surgical correction
Answer D.) Grossly aberrant ridge tissue should be surgically corrected prior to the final impression. Apontic designed to aberrant ridge tissue will trap plaque and debris in the infrasurface portion, resulting in inflammation.
20. Where there is a decrease by half or less of the inter-tooth space
A. make the pontic half size
B. use orthodontics to enlarge it
C. recontour adjacent teeth with inlay, onlay, or crown
D. extract a tooth to provide additional space
Answer C.) It is very important that one avoid match stick type pontics for this design usually causes plaque and food entrapment. It is more desirable to recontour adjacent teeth with inlays, onlays or crowns to close up a space that has been decreased by half or less of the intertooth space originally provided. These can be single, unsoldered units to allow for maintenance.
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