Prosthodontics1 Flashcards
(100 cards)
1
Q
The shape and amount of
• the distobuccal extension of a complete mandibular edentulous impression is determined during border molding by the ?
• The distolingual extension is limited by the action of ?
A
- position and action of the masseter muscle
* the superior constrictor muscle
2
Q
The most important consideration in checking custom trays for accurate border molding is ?
A
stability and lack of displacement
3
Q
The primary reasons for obtaining the most extensive areal coverage for a mandibular complete denture are:
• to increase the capacity of underlying structures to withstand the stress due to biting force and to improve appearance
• to provide balanced occlusion and to increase tongue space
• to increase the capacity of the underlying structures to withstand the stress due to biting force and to increase the effectiveness of the seal
• to improve retention and to increase tongue space
A
to increase the capacity of underlying structures to withstand the stress due to biting force and to increase the effectiveness of the seal (underextension of the peripheral border of a complete mandibular denture decreases tissue-bearing surfaces, thereby affecting denture stability. Marked ridge resorption will occur if a mandibular complete denture base terminates short of the retromolar pad)
4
Q
Mandibular dentures do not rely on suction from a peripheral seal for retention (as do maxillary dentures) but rather on denture stability in ?
A
covering as much basal bone as possible without impinging on the muscle attachments
5
Q
? in mandibular border molding is often the most difficult area to manage.
A
Retromylohyoid area
6
Q
Immediate dentures should be scheduled for relines at: • 1 month and 3 months post extraction • 4 months and 7 months post extraction • 5 months and 10 months post extraction • 1 year and 2 years post extraction
A
5 months and 10 months post extraction (Recontouring of the healing ridge progresses rapidly from four to six months and does not become stable in form until 10 -12 months post extraction)
7
Q
When a patient wears a complete maxillary denture against the six mandibular anterior teeth, it is very common to have to do a reline every so often due to ?
A
the loss of bone structure in the anterior maxillary arch
8
Q
All new dentures should be evaluated: • 3 hours after delivery • 12 hours after delivery • 24 hours after delivery • 48 hours after delivery
A
24 hours after delivery (done for the purpose of correcting undetected errors and adjusting areas that are causing tissue trauma)
9
Q
Posterior teeth that are set edge to edge may cause: • gagging • cheek biting • reduced taste • speech aberrations
A
cheek biting
10
Q
Lip biting may be due to ?
A
reduced muscle tone and/or a large anterior horizontal overlap
11
Q
Tongue biting may be caused by having ?
A
posterior teeth too far lingually
12
Q
Maxillary anterior teeth in a complete denture are usually arranged:
• facial to the ridge
• lingual to the ridge
• exactly over the ridge
A
facial to the ridge (Setting anterior teeth directly over the ridge usually causes poor esthetics of dentures)
13
Q
For most patients, the labial surface of the central incisor should be approximately ? mm anterior to the center of the incisive papilla
A
8
14
Q
? should support the lower lip when the teeth are in occlusion.
A
The labioincisal one-third of the maxillary central incisors
15
Q
A patient who wears a complete maxillary denture complains of a burning sensation in the palatal area of his/her mouth. This is indicative of too much pressure being exerted by the denture on the: • incisive foramen • palatal mucosa • hamular notch • posterior palatal seal
A
incisive foramen
16
Q
A burning sensation in the mandibular anterior area is caused by ?
A
pressure on the mental foramen
17
Q
A patient having trouble swallowing may have ?
A
insufficient interocclusal space — decreased freeway space caused by excessive vertical dimension of occlusion
18
Q
The best dietary advice for an elderly denture patient is to eat foods rich in ?
A
protein and vitamins A, C, D, and B complex
19
Q
Learning to chew satisfactorily with new dentures requires at least ? weeks. This time is spent on establishing new memory patterns for both facial and masticatory muscles.
A
6-8
20
Q
? can be ruined by the use of denture adhesives and home-reliners. These agents can modify the position of the denture on the ridge and as a result, change both vertical and centric relations.
A
Residual ridges
21
Q
The treatment plan for a patient indicates that both mandibular and maxillary immediate dentures are to be fabricated. The ideal way to do this is:
• fabricate the maxillary immediate denture first
• fabricate the mandibular immediate denture first
• fabricate the maxillary and mandibular immediate dentures at the same time
A
fabricate the maxillary and mandibular immediate dentures at the same time
22
Q
The duplication of the master cast used for the construction of the surgical template to be used at the time of immediate denture insertion is best made after ?
A
wax elimination and after the cast is trimmed
23
Q
A major advantage with immediate dentures is being able to ?
A
duplicate the position of the natural teeth
24
Q
The first step in the treatment of abused tissues in a patient with existing dentures is to: • fabricate a new set of dentures • reline the dentures • educate the patient • excise the abused tissues
A
educate the patient (The patient should understand both the cause of the tissue deterioration and the eventual outcome if the process is not arrested) then we should remove the dentures
25
The most important benefit of an overdenture (root-retained denture) is:
• the psychological comfort of avoiding the loss of all teeth
• the continuous functional feedback for the neuromuscular system from proprioceptors in the periodontal membrane
• the preservation of the alveolar ridge
• the improved support and stability for the denture
• the increased retention of the denture
the preservation of the alveolar ridge
26
The incisal edges of the maxillary anterior teeth should just touch the wet/dry line of the lower lip when enunciating which sound(s):
• linguoalveolar sounds or sibilants (such as s, z, sh, and ch)
• fricatives or labiodental sounds (such as f, v, or ph)
• b, p, and m sounds
• linguodental sounds (such as this, that, or those)
• fricatives or labiodental sounds (such as f, v, or ph)
27
A whistling sound with dentures is indicative of having ?
a posterior dental arch form that is too narrow or high.
28
The b, p, and m sounds: are made by contact of the lips. Note: ? can affect the production of these sounds
Insufficient lip support by the teeth or the labial flange
29
Note: The two most probable causes of a patient complaining that whenever he/she tries to make an "s" sound, it sounds like "th" are ?
* Incisor teeth are set too far palatally
| * Palate is made too thick
30
To evaluate vertical dimension, have the patient pronounce the s sound; the interincisal separation should be ?. This is known as ?
* 1 to 1.5 mm.
| * the closest speaking space
31
• If the teeth are positioned too far ?, the "t" will tend to sound like a "d."
If the teeth are positioned too far ?, the "d" will sound more like a "t."
* lingually
| * labially
32
? can result in clicking of teeth
An increased occlusal vertical dimension
33
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The primary role of anterior teeth on a denture is:
• to incise food
• occlusion
• esthetics
• stability of the denture
```
esthetics
34
Whistling when a patient speaks with dentures (complete or partial which replaces the incisors) may be caused by any of the following:
* Vertical overlap is not enough
* Horizontal overlap is too much
* The area palatal to the incisors is improperly contoured (too high or too narrow)
35
Do not set mandibular molars over the ascending area of the mandible because ?
the occlusal forces in the area will dislodge the mandibular denture
36
A patient has worn a complete maxillary denture for 8 years against mandibular anterior teeth (the remainder of the mandibular teeth are missing). She complains of looseness of the denture. Examination of the mouth shows an excessive amount of hyperplastic tissue at the anterior part of the maxillary ridge. The maxillary denture teeth do not show below the upper lip. Radiographs show poor bone structure in the anterior part of the maxillae. The principal cause of difficulty with her maxillary denture is:
• fibrous tuberosities
• too great a vertical dimension of occlusion
• a lack of posterior occlusion
• the maxillary denture teeth that were used are too short
a lack of posterior occlusion (The patient's chief complaint will be looseness of the maxillary denture. They will also state that they can no longer sec their upper teeth on the denture. These signs and symptoms are caused by a lack of posterior occlusion)
37
* Denture ? is necessary to resist dislodgement of a denture in the horizontal direction
* Denture ? is the ability of the denture to withstand dislodging forces exerted in the vertical plane.
* stability
| * retention
38
The primary indicator of the accuracy of border molding is:
• adequate coverage of tray borders with the material used for border molding
• contours of the periphery similar to the final form of the denture
• stability and lack of displacement of the tray in the mouth
• uniformly thick borders of the periphery
stability and lack of displacement of the tray in the mouth
39
After border molding is completed, some areas of the modeling compound should be relieved because the tissues are extremely displaceable and have probably been distorted during the border molding process. These areas include ?
around the maxillary labial frenum and over the retromolar pad areas
40
```
You are in the process of making a complete maxillary denture for a patient. Which of the following structure(s) will be the secondary support area (s):
• residual ridges
• palatal rugae
• incisive papilla
• maxillary tuberosity
• buccal vestibule
```
palatal rugae
| The primary support areas of the maxillary complete denture are the residual ridges (the maxillary and palatine bones).
41
In the mandibular arch,
• the primary support area is ?
• The secondary peripheral seal area for a mandibular complete denture is ?
* the buccal shelf
| * the anterior lingual border
42
The most important factor for providing retention for complete dentures is ?
the peripheral seal
43
```
An overextended distobuccal corner of a mandibular denture will push against which muscle during function?
• zygomaticus
• orbicularis oris
• temporalis
• masseter
```
masseter
44
```
After border molding the mandibular custom tray, it is important to check for dislodgement in order to detect areas of:
• underextension of the tray
• overextension of the tray
• thickness of the tray
• none of the above
```
overextension of the tray
45
The most critical area in the overextension of border-molding procedure for a maxillary denture is the ?. This area is extremely important for maximal retention.
mucogingival fold above the maxillary tuberosity area
46
Common areas of overextension of the mandibular impression are ?. This is suspected when the impression raises as the mouth is opened
the labial and the buccal
47
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Before an accurate face-bow transfer record can be made on a patient, which of the following must be determined?
• the inclination of each condyle
• vertical dimension of occlusion
• centric relation
• location of the hinge axis point
```
location of the hinge axis point — axial center of opening-closing (If the face-bow transfer procedure is properly done, the arc of closure on the articulator should duplicate that exhibited by the patient. This hinge-axis face-bow transfer enables alteration in vertical dimension on the articulator)
48
```
A plaster index is used to:
• maintain the vertical dimension of occlusion
• maintain bite registration
• preserve the face-bow transfer
• all of the above
```
preserve the face-bow transfer
49
```
A generalized speech difficulty with complete dentures is usually caused by which of the following? Select all that apply.
• faulty tooth position
• excess vertical dimension of occlusion
• faulty palatal contours
• faulty occlusion
```
* faulty tooth position
| * faulty palatal contours
50
Patients who have been edentulous for many years often have more distorted speech than those who have been edentulous for a short time. This is usually due to ?
a loss of tonus of the tongue musculature
51
At the first appointment after insertion of complete dentures, the presence of generalized soreness on the crest of the mandibular ridge is most likely due to:
• the newness of the denture
• defective tissue registration
• premature occlusal contacts
• incomplete polymerization of the denture base
premature occlusal contacts
52
```
The inferior surface of the maxillary occlusal rim should be parallel to:
• frankfort's plane
• camper's line
• fox plane
• horizontal condylar inclination
```
camper's line (which is an imaginary line traced from the inferior border of the ala of the nose to the tragus of the ear)
53
A good starting point for determining the vertical length of the maxillary occlusion rim is a point approximately ? mm below the upper lip when it is relaxed.
2
54
The most frequent cause of porosities in a denture is:
• insufficient pressure on the flask during processing
• insufficient material in the mold
• a rapid elevation in temperature to 212° F causing vaporization of the liquid
• insufficient time for processing
insufficient pressure on the flask during processing (under 20-30 psi air pressure)
Porosities will also occur if the packing and processing of the powder and liquid resin is too plastic (stringy or sandy). This permits the liquid to vaporize and, at the same time, does not allow sufficient pressure during closure of the flask
55
All of the following are disadvantages to immediate denture therapy. Which one is considered to be the major disadvantage to immediate denture therapy?
• increased post-insertion care
• increased post-insertion soreness
• not being able to have an anterior tooth try-in to evaluate esthetics
• greater complexity of clinical procedures
• a higher cost of treatment
not being able to have an anterior tooth try-in to evaluate esthetics
56
All of the following statements are true concerning a face-bow or a face-bow transfer EXCEPT one. Which one is the EXCEPTION?
• the face-bow is a caliper-like device used to record the patient's maxilla/hinge axis relationship (opening and closing axis)
• if the transfer is done properly, the arc of closure on the articulator should duplicate that exhibited by the patient
• the face-bow transfer is a maxillo-mandibular record
• the face-bow transfer is used to transfer the maxilla/hinge axis relationship to the articulator during the mounting of the maxillary cast
the face-bow transfer is a maxillo-mandibular record
57
The posterior palatal seal for a maxillary denture:
• is placed 3 mm posterior to the vibrating line
• is not necessary when fabricating a complete denture on a patient with a flat palate
• is not necessary if a metal base is used
• will vary in outline and depth according to the palatal form of the patient
will vary in outline and depth according to the palatal form of the patient
58
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Which of the following landmarks is least relevant to the location of the posterior palatal seal area?
• pterygomaxillary notch
• vibrating line
• hamular process
• fovea palatinae
```
hamular process
59
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Which of the following are morphological changes associated with the edentulous state. Select all that apply.
• deepening of nasolabial groove
• loss of labiodental angle
• retrognathic appearance
• decrease in horizontal labial angle
• narrowing of lips
• increase in columella-philtral angle
```
* deepening of nasolabial groove
* loss of labiodental angle
* decrease in horizontal labial angle
* narrowing of lips
* increase in columella-philtral angle
60
? is considered an essential starting point in the design of the artificial denture
The recording of centric relation
61
In metal-ceramic restorations, failure or fracture usually occurs:
• in the porcelain
• at the porcelain-metal interface
• in the metal
in the porcelain
62
* The necessary thickness of the metal substructure is ?mm
| * The minimal porcelain thickness is ?mm
* 0.5
| * 1.0-1.5
63
Porcelain fracture in all-ceramic restorations can be avoided by ?
keeping the angles of the preparation rounded
64
```
The strength of a solder joint is proportional to its:
• porosity
• thickness
• surface area
• all of the above
```
surface area (A good solder joint between 2 castings requires clean surfaces and free electrons present on the surfaces)
65
? solders are generally used for fixed bridgework and ? solders for orthodontic appliances
* Gold
| * silver
66
Which of the following are indications for fixed bridgework or important considerations to think about when contemplating (فکر کردن) the fabrication of fixed bridgework for a patient?
• a limited number of edentulous areas which would not otherwise be more satisfactorily restored with a removable partial denture
• the need to prevent the over-eruption of opposing teeth and the drift of teeth neighboring the edentulous space
•the presence of suitable abutment teeth — favorable crown/root ratio, adequate alveolar support, absence of apical pathology, etc.
• esthetics
• patient motivation, including time availability
• clinical and technical ability
• all of the above
all of the above
67
The bonding of the solder is contingent (مشروط) upon ? of the joined surfaces by the solder, and not upon ?
* wetting
| * melting of the metal components
68
```
Endodontically treated teeth that have been restored with a cast post and core, and crown, are subjected to the high incidence of:
• periodontal disease
• recurrent caries
• vertical root fracture
• the need for an apicoectomy
```
vertical root fracture (The main symptom will almost always be pain when biting. The radiograph usually appears normal)
69
All of the following are indications for porcelain veneers EXCEPT one. Which one is the EXCEPTION?
• coverage of labial surface defects — hypoplasia of the enamel
• masking of discolored teeth—tetracycline staining, discoloration following loss of vitality
• the severe imbrication of teeth
• repair of structural damage—fractured incisal edges
• improvement of tooth contour—peg-shaped lateral incisors
• reduction of spacing in cases when orthodontics would be inappropriate
the severe imbrication of teeth — this is a contraindication to porcelain veneers
70
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The absolute maximum number of posterior teeth, which can be safely replaced with a fixed bridge, is:
• one
• two
• three
• four
```
three — and three teeth should be replaced only under ideal conditions *** Any bridge replacing more than two teeth should be considered high risk
71
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A reverse 3/4 crown is most frequently fabricated for a:
• maxillary premolar
• mandibular premolar
• mandibular molar
• maxillary molar
```
mandibular molar (This design preserves the lingual surface and is indicated for restoring mandibular molars with damaged buccal surfaces and intact lingual surfaces. It is also useful on teeth with severe lingual inclinations where large quantities of tooth structure would be destroyed if a full veneer crown were to be used.)
72
* High noble alloys (old term was precious metal):
* Noble alloys (old term was semiprecious metal):
* Base metal alloys (old term was nonprecious metal):
* >60% noble metal content (gold > 40%)
* >25% noble metal content (no gold required)
* less than 25% noble metal content (no gold required)
73
Periodontal health of the gingival tissues is a major concern when planning any fixed prosthodontic treatment. For optimum periodontal health, restoration finish lines should be:
• within the sulcus at least 1.0 mm and away from the free gingival margin without encroaching on the biologic width
• terminated at the free gingival margin
• supragingival whenever possible (at least 0.5 mm from the free gingival margin) to allow for hygienic cleansing
• as far as possible subgingivally into the attachment apparatus
supragingival whenever possible (at least 0.5 mm from the free gingival margin) to allow for hygienic cleansing
74
The optimum margin for a casting is ? edge with a nearby bulk of metal. This acute edge or angle can be easily burnished to improve its fit.
an acute
75
? is the poorest type of finish line that can be used with cast metal restorations
A butt joint, as typified by a shoulder,
76
When casting conventional gold alloys, which type of investment material is used?
• silica-bonded investments
• phosphate-bonded investments
• gypsum-bonded investments
gypsum-bonded investments
77
Two types of Phosphate-bonded investments: Type I is used when casting ? for metal-ceramic crowns and Type II is used for ?. Are capable of withstanding high temperatures
* base metal alloys
| * removable partial denture frameworks
78
All of the following statements regarding metal-ceramic restorations are true EXCEPT one. Which one is the EXCEPTION?
• the metal and porcelain must have compatible melting temperatures as well as compatible coefficient of thermal expansions
• the metal's melting temperature should be at least 300-500°F higher than the fusing temperature of the porcelain
• the metal coping should preferably have sharp surfaces to prevent shrinkage of the porcelain
• in function, glazed porcelain on the occlusal surface removes 40 times as much of the opposing tooth structure than gold
the metal coping should preferably have sharp surfaces to prevent shrinkage of the porcelain
79
When preparing a tooth for either a full-or partial-veneer casting, the functional cusp bevel is an integral part of the occlusal reduction phase. The functional cusp bevel:
• enhances resistance form when buccal-to-lingual forces are applied
• serves as a positive stop when the casting is seated during cementation
• relieves the functional cusp from additional stresses when the restoration is loaded in the long axis of the tooth
• provides space for restorative material of adequate thickness in an area of heavy occlusal contact
provides space for restorative material of adequate thickness in an area of heavy occlusal contact
80
The path of insertion of an anterior three-quarter crown parallels ?. For a posterior three-quarter crown it parallels ?
* the incisal 1/2 to 2/3 of the labial surface, not the long axis of the tooth
* the long axis of the tooth.
81
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The preparation for a full veneer crown is begun with occlusal reduction. There should be ? clearance on the functional cusps and about ? on the non-functional cusps.
• 0.5 mm; 1.0 mm
• 1.5 mm; 1.0 mm
• 2.0 mm; 1.5 mm
• 2.5 mm; 2.0 mm
```
2.0 mm; 1.5 mm
82
Occlusal point contacts between opposing teeth are preferred to ? to prevent wear.
broad, flat occlusal contacts
83
Type ? gold alloys are used for inlays
| The most commonly used type of gold for all-metal crowns and bridges is Type ?
* I and II
| * III
84
Which of the following best describes "strain hardening" or "work hardening"?
• hardening (or deformation) of a metal at room temperature
• hardening (or deformation) of a metal at a very high temperature
• softening a metal by controlled heating and cooling
• softening a metal at room temperature
hardening (or deformation) of a metal at room temperature
85
Which of the following best describes the term "quenching"?
• a metal is elevated to a temperature above room temperature and held there for a length of time
• a metal is rapidly cooled from an elevated temperature to room temperature or below
• softening a metal by controlled heating and cooling
• none of the above
a metal is rapidly cooled from an elevated temperature to room temperature or below (It is usually performed when a complete gold crown is cast and immediately quenched in water. This softens the alloy, making it more malleable for finishing procedures)
86
Gypsum bonded investment material can be used for:
• dowel crowns to be cast in silver-palladium alloys
• titanium crowns and copings
• the substructure for metal ceramic crowns
• type IV gold alloys
• none of the above
• all of the above
dowel crowns to be cast in silver-palladium alloys (Dowel cores do not require as much expansion as do crowns. So even though they are cast with Ag-Pd alloys (alloys that require a high temperature for expansion), a gypsum bonded mold is used and heated to only 1200°F. Type I, II, and III Gold alloys can also be cast in gypsum bonded investment material)
87
The path of insertion for an anterior 3/4 crown should:
• be perpendicular to the incisal one-half of the labial surface rather than the long axis of the tooth
• be parallel to the incisal one-half to two-thirds of the labial surface rather than the long axis of the tooth
• be parallel to the long axis of the tooth
• be parallel to the cervical one -third of the labial surface rather than the long axis of the tooth
be parallel to the incisal one-half to two-thirds of the labial surface rather than the long axis of the tooth (If the path of insertion is made parallel to the long axis of the tooth, the labioincisal comer will be sacrificed and an unnecessary display of gold will result)
88
When treatment planning for fixed prosthodontics, which of the following information can be obtained by studying diagnostic casts? Select all that apply.
• the length of the abutment teeth can be accurately gauged
• the true inclination of the abutment teeth will be evident
• the presence of periodontal pockets
• the crown-to-root ratio of potential abutment teeth
• mesial/distal drifting, rotation, and faciolingual displacement of potential abutment teeth can be clearly seen
• curvature of the arch in the edentulous region can be determined
* the length of the abutment teeth can be accurately gauged
* the true inclination of the abutment teeth will be evident
* mesial/distal drifting, rotation, and faciolingual displacement of potential abutment teeth can be clearly seen
* curvature of the arch in the edentulous region can be determined
89
?, the more favorable the surface area:volume ratio and the lower the susceptibility to water loss or gain and, therefore, unwanted dimensional change
The greater the bulk that the alginate has
90
The alginate impression should be rinsed and disinfected with ?
glutaraldehyde or iodophor before pouring
91
All of the following statements concerning pontics are true EXCEPT one. Which one is the EXCEPTION?
• with regard to the ease of cleaning and good tissue health; proper pontic design is more important than the choice of material used in fabricating the pontic
• the contour and nature of the pontic contact with the ridge is very important
• the area of contact between the pontic and the ridge should be small
• the portion of the pontic approximating the ridge should be as concave as possible
• the pontic should exert no pressure on the ridge (passive contact with no blanching of the tissue)
the portion of the pontic approximating the ridge should be as concave as possible
92
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The ideal crown-to-root ratio of a tooth to be utilized as a bridge abutment is:
• 3:1
• 2:1
• 1:2
• 1:1
```
1:2 (A ratio of 1:1 is the minimum ratio that is acceptable for a prospective abutment under normal circumstances)
93
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Soldering flux is composed of all of the following EXCEPT one. Which one is the EXCEPTION?
• sodium pyroborate
• alum
• borax
• silica
```
alum
94
The recommended distance (width) between the parts to be joined by soldering should be ? mm.
0.25
95
When it melts, the flux displaces gases and removes corrosion products by ?
either combining with them or reducing them
96
Note: Antiflux is a material used to outline the area to be soldered in order to restrict the flow of solder. The most common antiflux is ?
a soft graphite pencil
97
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What type of pontic design would you use in a patient with a high esthetic demand when preparing teeth numbers 9-11 for a fixed partial denture?
• the saddle-ridge-lap pontic
• the sanitary (hygienic) pontic
• the modified ridge-lap pontic
• an ovate pontic
• a conical pontic
```
the modified ridge-lap pontic
98
? pontic design leaves a space between the pontic and the ridge
The sanitary (hygienic)
99
The faciolingual dimension of the occlusal portion of pontics is determined by ?
the faciolingual position of the opposing centric holding contact areas
100
The most important clinical property of a cement is solubility.
Increasing a cement's powder-to-liquid ratio increases the solubility of the cement.
• 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
the first statement is true, the second is false
