Endo1 Flashcards
1
Q
Which of the following is a clinical diagnosis based on subjective and objective findings indicating that the vital inflamed pulp is incapable of healing and has the following additional descriptors: lingering thermal pain, spontaneous pain, and referred pain? • reversible pulpitis • asymptomatic irreversible pulpitis • symptomatic irreversible pulpits • none of the above
A
symptomatic irreversible pulpits
2
Q
Which of the following is an inflammatory reaction to pulpal infection and necrosis characterized by rapid onset, spontaneous pain, tenderness of the tooth to pressure, pus formation and swelling of associated tissues? • symptomatic apical periodontitis • acute apical abscess • chronic apical abscess • asymptomatic apical periodontitis
A
acute apical abscess
3
Q
Chronic Apical Abscess?
A
An inflammatory reaction to pulpal infection and necrosis characterized by gradual onset, little or no discomfort, and the intermittent discharge of pus through an associated sinus tract
4
Q
Which of the following are related to vital teeth and usually do not warrant endodontic therapy? Select all that apply. • apical scar • cementoma • traumatic bone cyst • globulomaxillary cyst • radicular cyst
A
• cementoma (usually lower anterior teeth which are vital)
• traumatic bone cyst (teeth are vital, scalloped appearance)
• globulomaxillary cyst (between upper 2&3, teeth are vital)
in apical scar and radicular cyst, teeth are nonvital
5
Q
The most superior of all other retrofilling material -- mineral trioxide aggregate (MTA) has all of the following advantages, EXCEPT two. Which TWO are not properties of MTA? • radiopaque • easy to manipulate • hydrophilic • biocompatible • not toxic • short setting time • induction of hard tissue formation
A
- easy to manipulate
* short setting time
6
Q
blood contaminants of MTA
A
not adversely effected
7
Q
Teeth that have ? and need to be retreated are the most common reason for an apicoectomy and a retrograde filling
A
posts in them
8
Q
The earliest and most common symptom associated with an inflamed pulp is: • a dull throbbing pain on mastication • sensitivity to hot and/or cold stimuli • a persistent feeling of discomfort • mild bleeding • pain on percussion
A
sensitivity to hot and/or cold stimuli (thermal sensitivity)
9
Q
The best method to elicit the most accurate thermal response is to ?. This is done because all other methods may stimulate the tooth at only one section of one surface.
A
individually isolate the suspected teeth with a rubber dam and then bathe each tooth in hot or cold water (usually stick of ice and warm stick of gutta percha are used)
10
Q
Thermal tests may be false-negative in ?
A
immature, recently traumatized teeth or because of premedication with an analgesic
11
Q
Although the percussion test does not indicate the health of the pulp, the sensitivity of the proprioceptive fibers does reveal ?
A
inflammation of the apical PDL
12
Q
A positive response to percussion indicates ?
A
- not only the presence of inflammation of the PDL,
* but also the extent of the inflammatory process
13
Q
A phoenix abscess is also known as a: • recrudescent abscess • granuloma • cyst • none of the above
A
recrudescent abscess (identical to those of an acute apical abscess, but a radiograph will show a large periapical radiolucency that indicates the presence of a chronic disease)
14
Q
A phoenix abscess is always preceded by ?
A
asymptomatic apical periodontitis.
15
Q
A massive invasion of pulpal contaminants to granuloma will result in the formation of ?
A
an acute abscess (phoenix abscess)
16
Q
A granuloma or a cyst can only be differentially diagnosed by ?
A
histological examination.
17
Q
Which of the following defines the difference between a chronic apical abscess and a periapical cyst/granuloma?
• chronic apical abscess is asymptomatic
• chronic apical abscess is symptomatic
• only histological examination can differentiate
• the border of the radiolucent lesion
A
only histological examination can differentiate
18
Q
? of bone calcium must be altered before radiographic evidence of periapical breakdown occurs
A
30% to 50%
19
Q
the best treatment of an acute apical abscess includes ? which will relieve the acute symptoms. This is followed at a later date by conventional root canal therapy
A
establishing drainage and debriding the canal system of necrotic tissue
20
Q
A patient is diagnosed with symptomatic apical periodontitis and refuses treatment due to fear of needles. Your statement to the patient should include the fact that:
• eventually, the acute nature of the lesion will progress into a chronic and nonpainful lesion
• this lesion can progress into the bone causing osteomyelitis, a more severe condition
• the apical lesion has been there for years and the tooth needs treatment immediately
• none of the above
A
this lesion can progress into the bone causing osteomyelitis, a more severe condition (Osteomyelitis is not a particularly common disease. It is a serious sequela of periapical infection that often results in a diffuse spread of infection throughout the medullary spaces, with subsequent necrosis of a variable amount of bone)
21
Q
Radiographically, acute osteomyelitis progresses ? and demonstrates little radiographic evidence of its presence until ?. At that time, diffuse lytic changes in the bone begin to appear. Note: A ? radiolucent appearance is evident.
A
- rapidly (more in mandible)
- the disease has developed for at least 1 to 2 weeks
- “moth-eaten”
22
Q
The general principles of acute osteomyelitis treatment demand that ?
A
drainage be established and maintained and that the infection be treated with antibiotics to prevent further spread and complications.
23
Q
An acute apical abscess will not respond to pulp vitality tests.
An acute apical abscess is only observed in association with a necrotic pulp.
• both statements are true
• both statements are false
• the first statement is true, the second is false
• the first statement is false, the second is true
A
both statements are true
24
Q
Emergency treatment of acute apical abscess includes ?
A
establishing drainage (ideally through the canal) and prescribing antibiotics (only if indicated by systemic signs and elevated temperature) and analgesics.
25
When diffuse swelling exists, the swelling has dissected into fascial spaces. The most important objective is ?
the removal of the irritant via canal debridement or extraction of the offending tooth. Swelling may be incised and drained followed by drain insertion and systemic antibiotics
26
Condensing Osteitis is a diffuse radiopaque lesion representing a localized bony reaction to a low-grade inflammatory stimulus, usually seen at apex of tooth.
Reversible pulpitis is a clinical diagnosis based upon subjective and objective findings indicating that the inflammation should resolve and the pulp return to normal.
• both statements are true
• both statements are false
• the first statement is true, the second is false
• the first statement is false, the second is true
both statements are true
27
A 7-year-old boy arrives at the office with a complaint that tooth #8 is draining pus into his mouth. The tooth had been traumatized earlier. The vitality tests reveal no response. What is the treatment of choice? Select all that apply.
• extraction
• apexogenesis / pulpotomy
• pulpectomy
• periodontal surgery to remove sinus tract
• it is only necessary to give the child analgesics and antibiotics for pain and infection
• apexification
• pulpectomy
• apexification
The goal of apexification is to induce further root development in a pulpless tooth by stimulating the formation of a hard substance at the apex, so as to allow obturation of the root canal space. Apexification may be required after pulpectomy if the apex of the tooth is open. Remember: Apex closes 2-3 years after eruption
28
The patient of apexification is recalled after ?
3 months to see if apexification has taken place. If not, a fresh supply of paste is placed. If apexification has occurred, conventional root canal therapy is instituted.
29
All of the following statements regarding adjuncts to endodontic treatment are true EXCEPT one. Which one is the EXCEPTION?
•transplanted teeth with partial root development have a better prognosis than do those with developed roots
• orthodontic extrusion is commonly indicated prior to implant placement
• intentional replantation is a viable alternative to endodontic surgery
• a major disadvantage of endodontic implants is the lack of an apical seal
intentional replantation is a viable alternative to endodontic surgery (Intentional replantation is not a substitute for endodontic surgery whenever endodontic surgery can be performed)
30
Which of the following is the most characteristic radiographic evidence of a vertical root fracture?
• a persistent periodontal defect
• a radiolucent halo surrounding the root of the fracture
• a radiopaque lesion at the sight of the fracture
• a visible fracture when transillumination is used
a radiolucent halo surrounding the root of the fracture (Also, persistent periodontal defects are often caused by vertical root fractures; however, this is not radiographic. Radiographs (without first wedging the tooth) rarely will show vertical fractures.)
31
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A patient complains of a slight tooth ache that has been "on and off" for a week. The tooth in question #18. Which of the following teeth would be optimum to use as a baseline?
• #19 -virgin
• #15 - primary cavitation on occlusal
• #3 - full gold crown
• #30 - occlusal amalgam
```
#19 -virgin
32
electric pulp tester (EPT) checks the sensibility of a tooth by stimulating nerve endings with ? in voltage
a low current and high potential difference (it stimulates the A-delta sensory fibers in the pulp)
33
If a patient's medical history reveals that a cardiac pacemaker has been implanted, the use of an electric pulp tester is ?
contraindicated
34
The main concept of the cone shift technique is that as the vertical or horizontal angulations of the x-ray tube head changes, the object buccal or closest to the tube head moves to ? the side of the radiograph when compared to the lingual object.
• same
• opposite
opposite
35
A disadvantage of the cone shift technique is that it results in ?, which is directly proportional to cone angle
blurring of the object
36
```
Your practice is involved with a local minor hockey team, the Millwrights. A player gets hit with a stick, and his central incisors are intruded. Which of the following is the least useful examination procedure?
• soft tissue exam
• hard tissue exam
• radiograph
• vitality test
• percussion test
```
vitality test (This test is contraindicated. The percussion test is usually not performed because of its pain. However, the vitality test will give you a truly false reading, because of temporary paresthesia in the area)
37
? require endodontic treatment more often than any other tooth, while ? have the highest endodontic failure rate.
• mandibular first molars, maxillary first molars
• mandibular first molars, maxillary second molars
• maxillary second molars, mandibular first molars
• maxillary first molars, mandibular first molars
mandibular first molars, maxillary first molars
38
In mandibular first molars, you must look for the fourth canal if ?
the first-found canal in the distal root lies more toward the buccal instead of being located in the center
39
* Maxillary molars have ? outline of the chamber
| * Mandibular molars have ? outline of the chamber
* a triangle
| * a trapezoidal
40
Which of the following are correct associations? Select all that apply.
• maxillary incisors most often refer pain to the forehead region
• maxillary second premolars most often refer pain to the temporal region
• maxillary molars most often refer pain to the ear
• manbibular molars most often refer pain to posterior region of the neck
* maxillary incisors most often refer pain to the forehead region
* maxillary second premolars most often refer pain to the temporal region
* manbibular molars most often refer pain to posterior region of the neck
41
```
Which of the following teeth is most likely to have two canals, in fact, it has two canals most of the time?
• tooth #4
• tooth #12
• tooth #20
• tooth #28
```
tooth #12 (maxillary first premolars almost always have two canals)
42
Remember: Maxillary second premolars have a higher incidence of ? , than do maxillary first premolars
accessory canals (60%)
43
One year after performing endodontic treatment on tooth #3, you take a new periapical radiograph and notice that there is still a lesion present. What is the most likely problem?
• you failed to locate a second mesiobuccal canal
• you failed to locate a second distobuccal canal
• you failed to locate a second palatal canal
• nothing, it takes more than 12 months for the bone to heal
you failed to locate a second mesiobuccal canal
44
The DB orifice to this canal has no direct relation to ?. The distobuccal orifice is usually located by means of ?, with the distobuccal found approximately 2 to 3 mm to the distal and slightly to the palatal aspect of the mesiobuccal orifice.
* its cusp
| * its relation to the mesiobuccal orifice
45
The U-shaped radiopacity commonly seen overlying the apex of the palatal root of the maxillary first molar is most likely ?
the zygomatic process of the maxilla.
46
```
Which of the following teeth have pulp chambers that can be characterized as oval or ovoid? Select all that apply.
• maxillary central incisor
• mandibular central incisor
• maxillary lateral incisor
• mandibular lateral incisor
```
* mandibular central incisor
* maxillary lateral incisor
* mandibular lateral incisor
47
```
Approximately what percentage of mandibular first premolars may have two canals with two apical foramina?
• 5%
• 20%
• 45%
• 65%
```
20% (-25%)
48
If a straight-on preoperative radiograph of a mandibular first premolar shows the pulp canal disappearing (or going from dark to light) in midroot, this is an important indication that ?
two canals are present
49
A mandibular canine typically requires an oval access preparation.
The access should be directed slightly toward the lingual surface due to slight labial axial inclination of the crown.
• both statements are true
• both statements are false
• the first statement is true, the second is false
• the first statement is false, the second is true
both statements are true
50
```
Which of the following teeth is most likely to have a curved root?
• maxillary central incisor
• maxillary lateral incisor
• maxillary canine
• mandibular central incisor
```
maxillary lateral incisor (distal curve)
51
While doing a vital pulpotomy on a young, immature permanent tooth, the hemorrhage after pulp amputation could not be controlled with cotton pellets, even after several minutes. What is the next step in completing this treatment?
• control the hemorrhage with hemostatic agents
• apply formocresol with cotton pellets at the amputation site
• irrigate the canal with sodium hypochlorite then apply calcium hydroxide
• perform the amputation at a more apical level
• stop the procedure and close the tooth with an interim restoration
• all of the above
perform the amputation at a more apical level (If bleeding does not stop even after more apical amputation, hemostatic agents are used as a compromise treatment)
52
Uncontrolled bleeding in puplotomy is a sign of ?
inflamed pulp tissue
53
Pulpotomy indication?
* Cariously exposed deciduous teeth — with healthy radicular pulps
* Traumatic or carious exposure of permanent teeth with undeveloped roots
* An alternative to extraction when endodontic treatment is not available
* Emergency treatment in permanent teeth with acute pulpitis
54
```
Which of the following situations offer better success for pulp capping? Select all that apply.
• accidental exposure of the pulp
• pulp of a middle-aged person
• carious exposure of the pulp
• pulp of a young child
```
* accidental exposure of the pulp
| * pulp of a young child
55
pulp capping means?
sedative and antiseptic dressing (Dycal) on an exposed healthy pulp to allow it to recover and maintain normal function and vitality
56
In which of the following scenarios would you consider using solvent-softened custom cones? Select all that apply.
• lack of an apical stop
• an abnormally large apical portion of the canal
• an irregular apical portion of the canal
• after an apexification procedure
• lack of an apical stop
• an abnormally large apical portion of the canal
• an irregular apical portion of the canal
• after an apexification procedure
Studies show that solvent softening does not ultimately result in a better apical seal.
57
The main reason for recapitulation (using your MAF after each increase in file size) during instrumentation of the canal is ?
to clean the apical segment of the canal of any dentin filings that were not removed by irrigation
58
During the master cone fitting procedure in the endodontic treatment of a patient's tooth, the patient says he has a "sharp shooting pain in the same tooth that ached earlier." What should be your response and why?
• continue with obturation, the anesthetic is simply wearing off
• continue with obturation, this is a normal complaint during this part of the procedure
• consider looking for an accessory canal and refiling, there is likely pulpal tissue that has not been properly debrided
• irrigate further, the sodium hypochlorite should take care of this problem
• temporize the tooth and obturate at a later date
consider looking for an accessory canal and refiling, there is likely pulpal tissue that has not been properly debrided (This indicates inadequate debridement, as a pulpless tooth should not respond to any stimuli)
59
canal obturation (filling) and canal debridement (cleaning), which is the key to success?
canal debridement
60
The presence of a periapical lesion before root canal treatment will reduce the success rate of the treatment by ?
10%-20%.
61
```
Which of the following are suggested as irrigants during root canal therapy? Select all that apply.
• orea peroxide (Gly-Oxide)
• hydrogen peroxide
• sodium hypochlorite
• calcium hydroxide
```
* orea peroxide (Gly-Oxide) (The best use for Gly-Oxide is in narrow and/or curved canals, utilizing the slippery effect of the glycerol)
* hydrogen peroxide (3% solution)
* sodium hypochlorite (A 5.25% solution is mostly used and provides excellent germicidal solvent action)
62
```
You are retreating a previously root canal treated tooth. Which of the following might you possibly use? Select all that apply.
• rotary files
• chloroform
• glass bead sterilizer
• ultrasonic
• heated instruments
```
* rotary files
* chloroform
* ultrasonic
* heated instruments
63
Which of the following statements regarding ethylene diamine tetra-acetic acid (EDTA) are true? Select all that apply.
• it is a chelating agent with the capability to remove the mineralized portion of the smear layer
• it can decalcify up to a 50 mm thin layer of the root canal wall
• it is also an excellent irrigation solution
• normally used in a concentration of 17%
• RC-Prep and EDTAC are other preparations of EDTA
• it can be used in place of NaOCI
* it is a chelating agent with the capability to remove the mineralized portion of the smear layer
* it can decalcify up to a 50 mm thin layer of the root canal wall
* normally used in a concentration of 17%
* RC-Prep and EDTAC are other preparations of EDTA
64
EDTA will remain active in the canal for ?
5 days
65
The most acceptable method to achieve adequate root canal debridement is:
• to obtain clean shavings of the canal
• to attain a clean irrigating solution
• to achieve glassy smooth walls of the canal
• all of the above criteria are reliable
• none of the above criteria is acceptable
to achieve glassy smooth walls of the canal (Clean shavings are difficult to see on a file. The attainment of a clean irrigating solution is considered an inaccurate way to determine the end point of debridement)
66
While cleaning and shaping the canal, an instrument seperates in the canal. As you attempt to retrieve it, the broken instrument passes partially through the apex, thus partly protruding into the periapical lesion. How do you manage this case?
• use a smaller H file to bypass it and try retrieving it
• use Gates Glidden drills to widen the canal and then try retrieving it
• raise a flap and remove the instrument surgically followed by filling the canal with gutta-percha
• extract the tooth as irreparable damage has occurred to the apex
• just inform the patient, fill the canal with gutta-percha, and monitor
raise a flap and remove the instrument surgically followed by filling the canal with gutta-percha
(past the apex is the key)
67
When an instrument breaks off anywhere in the canal and a periapical radiolucency is present and minimal canal enlargement has been performed before breaking the file, ? since the periapical tissues have had little opportunity for healing to be stimulated. You would prepare and obturate to the point of blockage and then perform an apicoectomy and retrofilling.
surgery is indicated
68
However, when an instrument is broken off in the apical third and is lodged tightly with no periapical radiolucency evident, the remaining root canal space ?
can be filled. The patient should be informed of this and placed on a 3-6 month recall. (Important: Prognosis of a tooth with a broken instrument is best if the tooth had a vital pulp and no periapical lesion)
69
```
Which of the following are acceptable methods to clean and shape a canal using nickel titanium instruments?
• push and pull stroke
• reaming motion
• engine-driven rotary motion
• All of the above
```
All of the above (The engine-driven instruments, however, use only the reaming motion)
70
? is recommended if using a silver cone to fill canals.
Reaming
71
```
The major advantage of zinc oxide-eugenol based sealer types is:
• non-staining property
• fast setting time
• adhesion
• insolubility
• long history of successful usage
```
long history of successful usage (staining, slow setting time, non-adhesion, solubility are disadvantages)
72
The primary function of a root canal sealer is to ?. In fact, it is said that it is ? than the core-filling material
* fill in the discrepancies between the core-filling material and the dentin wall
* more important
73
After filling a tooth with gutta-percha, if you see a horizontal line of material (gutta-percha or sealer) extending both mesially and distally from the canal to the periodontal ligament space, this is indicative of a ?
root fracture
74
Which tooth is IMPROPERLY matched with the reason for difficulty of its access preparation?
• maxillary first premolar - mesial concavity
• maxillary molar - proximity of canals to distobuccal line angle
• mandibular molar - mesio lingual tilt of tooth
• mandibular incisor - narrow mesial distal dimension
maxillary molar - proximity of canals to distobuccal line angle
75
A facial approach is recommended for an access opening on ?
maxillary primary incisors.
76
The action of using a file often dictates the shape of the canal.
A reaming action produces a canal that is relatively round in shape.
• both statements are true
• both statements are false
• the first statement is true, the second is false
• the first statement is false, the second is true
both statements are true (Studies have shown that the action of using the instrument, rather than the instrument used, determines the general shape of the canal preparation. Therefore, a reaming action produces a canal that is relatively round in shape while a filing action produces a canal that is irregular in shape)
77
Which of the following statements are true regarding files? Select all that apply.
• broaches can be used for canal enlargement
• k-type files can be machined or twisted
• significant apical pressure is needed when using a broach
• stainless steel files are less flexible than NiTi files
* k-type files can be machined or twisted
| * stainless steel files are less flexible than NiTi files
78
A size-10 file (with .02 taper) is indicated to be ? mm in width at D1 and .10 mm plus 0.30 mm (or 0.40 mm) at a point 16 mm farther up the shaft (D2)
0.10
79
```
Which cells do not characterize the cellular response at the onset of chronic pulpal inflammation?
• plasma cells
• macrophages
• lymphocytes
• polymorphonuclear (PMN) leukocytes
```
polymorphonuclear (PMN) leukocytes (these are for acute pulpal inflammation)
80
pH of Calcium hydroxide ?
12.5 (high, cauterizes tissue and causes superficial necrosis. This necrotic zone encourages the pulp to induce hard tissue repair with secondary odontoblasts laying down reparative dentin.)
81
```
A patient presents with all the characteristics of pulpal pathosis. Your assistant hands you an x-ray that shows no evidence of any restoration or caries. At first you don't believe that the x-ray is from the right patient, but it is. This scenario is pathognomonic of:
• condensing osteitis
• a vertical fracture of the tooth
• periodontal abscess
• secondary occlusal trauma
```
a vertical fracture of the tooth
82
There are multiple techniques for internal bleaching.
Hydrogen peroxide is a key ingredient in all of them.
• both statements are true
• both statements are false
• the first statement is true, the second is false
• the first statement is false, the second is true
both statements are true (sodium perborate is more easily controlled and safer than Superoxol; therefore, it is the material of choice.)
83
Tooth # 9 requires root-end surgery. Which flap design is generally NOT indicated?
• a submarginal curved flap (semilunar)
• a submarginal scalloped flap (Ochsenbein-Luebke)
• a full mucoperiosteal flap (triangular, rectangular, trapezoidal, horizontal)
• none of the above
a submarginal curved flap (semilunar)
84
? flaps allow maximal access and visibility. They are raised from the gingival sulcus (elevating gingival crest and interdental gingiva). This wide outline of the flap precludes any incisions over bony defects and allows various periodontal procedures including curettage, root planing, and bone reshaping.
Full mucoperiosteal (triangular, rectangular, trapezoidal, horizontal)
85
In which of the following cases could a dentist choose not to perform root canal therapy even when it is advised?
• on a nonrestorable tooth
• on a periodontally insufficient tooth
• on a tooth with a vertical root fracture
• on an asymptomatic tooth with a calcified chamber
• on a tooth that has massive external resorption
on an asymptomatic tooth with a calcified chamber (In all the other scenarios, root canal therapy is contraindicated)
86
The only systemic contraindications to endodontic therapy are ?
uncontrolled diabetes or a very recent myocardial infarction (within the past 6 months). In hemophilia we can do endo, but with a clearance from his physician
87
```
A periodontal probing defect that may not be managed by endodontic treatment alone is:
• a conical shaped probing
• a narrow sinus tract type probing
• a blow-out (acute) type probing
• none of the above
```
a conical shaped probing (this is typical primarily of a periodontal problem) (In "blow-out type" and "sinus tract type" probings, another clue for diagnosis is a nonvital (necrosed) pulp — these two lesions can completely heal after root canal treatment)
88
To distinguish a periodontal lesion from an endodontic lesion, ? are essential
pulp vitality tests along with periodontal probing
89
A common clinical finding of a periodontal problem is pain to ? on a tooth with a wide sulcular pocket
lateral percussion
90
Regarding the restoration of endodontically treated teeth, all of the following are generally believed to be true EXCEPT one. Which one is the EXCEPTION?
• a major disadvantage of posts/dowels is that they do not reinforce the tooth structure, in fact, they weaken it
• all post designs are predisposed to leakage
• at least 4 mm of gutta-percha must remain to preserve the apical seal
• threaded screw posts are preferred over parallel-sided and tapered posts
• pins add to stresses and microfractures in dentin and should not be used
• cusps adjacent to lost marginal ridges should be restored with an onlay
threaded screw posts are preferred over parallel-sided and tapered posts
91
If you are performing a pulp chamber-retained amalgam, you need to place amalgam ?mm into each canal for retention
3
92
Endodontically treated teeth do not become brittle. The moisture content of endodontically treated teeth is not reduced even after 10 years. Key point: ?
Teeth are weakened by the loss of tooth structure
93
Retreating a tooth with a post is the most common reason for an apicoectomy and retrograde filling.
Whenever a reverse filling procedure is to be used, apicoectomy is mandatory to provide a table into which the preparation and filling will be placed.
• both statements are true
• both statements are false
• the first statement is true, the second is false
• the first statement is false, the second is true
both statements are true
94
Endodontic procedures involve taking multiple radiographs. How should you protect yourself or your staff while taking radiographs if there is no barrier available to stand behind?
• stand at least 4 feet away anywhere around the patient
• stand at least 5 feet away exactly opposite the x-ray beam source
• stand at least 6 feet away and in the area that lies between 90 to 135 degrees to x-ray beam
• stand at least 7 feet away and in the area that lies between 60 to 90 degrees to x-ray beam
• never take an x-ray without a barrier
stand at least 6 feet away and in the area that lies between 90 to 135 degrees to x-ray beam
95
Dental personnel who may get exposed to occupational x-radiation must wear film badges to record exposure and must never exceed the maximum permissible dose (MPD) of ?
0.05 Sv/year
96
Most bacteria in endodontic infections are strict anaerobes.
The diversity of polymicrobial endodontic infections has been well established isolating anywhere from 3 to 12 species of microbes in the majority of endodontic infections.
• both statements are true
• both statements are false
• the first statement is true, the second is false
• the first statement is false, the second is true
both statements are true
97
During a routine radiographic evaluation, you notice bone loss extending from the cementoenamel junction to the apex of tooth #21. Further evaluation reveals that probing depths are above normal limits all around the tooth. However, at one point, the probe drops precipitously to an even greater depth. Vitality test is negative. This patient may require:
• extensive periodontal treatment followed by vitality reassessment
• endodontic treatment only
• endodontic treatment followed by periodontic treatment
• root-end surgery
• periodontic treatment followed by endodontic treatment
endodontic treatment followed by periodontic treatment
98
The combination lesion (perio-endo) is dominated by ? bacteria
gram-negative anaerobic
