Final Flashcards
1
Q
What is the path of insertion for most RPDs?
A
Straight
2
Q
What are the indications for rotational path RPDs in the sagittal plane?
A
- Maxillary and mandibular class IVs without modification spaces where visible clasping isn’t an option (A-P path)
- Mandibular class IIIs with mesially tipped molar abutments and bilateral edentulous segments (P-A path)
3
Q
What are the indications for path of insertion for the frontal plane?
A
- Maxillary and mandibular class IIs (lateral path)
- Class IIIs (unilateral) with no modification spaces (lateral)
4
Q
Maxillary and mandibular class IIs as well as class IIIs with no modification spaces are best suited for what type of path of insertion?
A
Lateral path (frontal plane)
5
Q
Maxillary and mandibular class IVs without modification spaces are suited for what path of insertion?
A
Anterior-posterior path
6
Q
Mandibular class IIIs with mesially tipped molar abutments and bilateral edentulous segments and best suited for what path?
A
Posterior-anterior path
7
Q
What are design considerations for rotational path RPDs?
A
- If there is no straight path of placement
- Eliminate unesthetic clasps (esp class IV)
- Clasps replaced by rigid retainers
- Rigid retainers (struts or plates) engage undercuts
- Little tolerance for error
8
Q
Does changing the path of insertion increase or decrease the number of clasps?
A
decrease
9
Q
Is there usually minimal or aggressive tooth preparation when preparing RPDs with another path of insertion?
A
Minimal; maximal in mesial tipped molars and maxillary canines in class IV
10
Q
Are rotational path RPDs easier to clean?
A
Yes
11
Q
Are rotational path RPDs more esthetic?
A
Yes
12
Q
Can a rotational RPD be made if there is an absence of facial undercuts in a kennedy class IV?
A
Yes
13
Q
Which are easily more distortable: clasps or rigid plates?
A
Clasps - thus since rotational RPDs use rigid plates there is less distortion of retentive components
14
Q
Do rotational RPDs preserve the integrity of the arch more or less than traditional RPDs?
A
More arch preservation (for eg: no need for embrasure clasps)
15
Q
What are some disadvantages of rotational RPDs?
A
- Adjustment of retentive components is difficult
- Less tolerance for error
- Requires well prepared rest seats
16
Q
For what classes are lateral path of placement RPDs made for?
A
Class IIs and IIIs without modification spaces
17
Q
The struts on a lateral path of placement RPD engage what undercuts?
A
Palatal or lingual plating engage undercuts on the fully dentate side
18
Q
Is the occlusal rest connected or not connected in a lateral path of placement RPD?
A
Connected
19
Q
Class I’s and II’s require passive rotational placement. Does a lateral path of placement RPD require a reciprocal element?
A
No
20
Q
What part of the lateral path RPD engages the teeth first to stabilize it?
A
Rest
21
Q
What part of the lateral path RPD engages second to rotate the RPD into the undercut without deformation or pressure on abutment teeth?
A
The retentive plate or strut
22
Q
Is the lateral path RPD inserted from left to right or from right to left?
A
Left to right
23
Q
How is the lateral path RPD removed?
A
Right to left
24
Q
What class is indicated for the use of a P-A path of insertion?
A
Mandibular class III with mesially tipped molars
25
What is the primary retention of a P-A path RPD on the mandibular class III mesially tilted molar?
Mesial plate on a .01 undercut; no clasps
26
How are the occlusal rests on the molars prepared for a P-A RPD?
- Depth: 1.5-2mm
- Floor of the rest is perpendicular to the long axis of the tooth
- The length should extend more than the FL dimension of the abutment tooth
- Asymmetric outline
- Bilaterally parallel walls on the facial lingual
- Intimate contact of rest and minor connector
27
What is the depth of the extended occlusal rest for the mandibular molar abutments?
1.5-2mm
28
Which walls in the extended occlusal rest are bilaterally parallel? Facial and lingual or mesial and distal?
Facial and lingual
29
Is the extended occlusal rest symmetrical or asymmetrical?
Asymmetrical because it has to be more than the FL dimension of the tooth
30
Is the floor of the rest parallel or perpendicular to the long axis of the tooth?
Perpendicular
31
What engages first in a P-A path of placement RPD to initially stabalize the RPD?
The rest
32
What engages second in a P-A RPD that allows it to rotate into the undercut without deformation?
Retentive plate or strut
33
Is there any horizontal force on the P-A molar abutment tooth when placing the RPD?
No
34
Since there is no horizontal force of the abutment tooth in a P-A RPD, during placement, is there then a requirement for reciprocation?
No
35
What class is more readily indicated for an A-P path of placement?
Maxillary and mandibular class IV
36
Why is an A-P path of placement better suited for a class IV case?
Because anterior clasping is eliminated so it is more esthetic
37
Which teeth are used as anterior abutments for A-P path of placement RPDs?
Canines and 1st/2nd bicuspids with .01" mesial undercuts
38
Are the undercuts on the canines and 1st/2nd bicuspids for the A-P RPD on the mesial or distal?
Mesial
39
What rests are made on the canines for an A-P RPD?
Cingulum rest
40
What rests can be made on the occlusal surface of the bicuspids for an A-P RPD?
Mesio-occlusal of abutment teeth (1st/2nd) bi's
| Mesio-occlusal of 2nd bicuspids with 1st bicuspid abutments
41
What is the rest preparation depth for the cingulum rest on MX canines for an A-P RPD?
1.5mm
42
What is the shape of the strut made for the MX canine's cingulum rest?
Chevron shaped
43
What engages first when a A-P RPD is inserted into the mouth?
The retentive plate and rest engage simultaneously
44
When the A-P RPD is first inserted what is the initial path of insertion?
Straight
45
Does an A-P RPD need reciprocation?
No
46
What are the posterior abutment teeth for an A-P RPD?
1st or 2nd molars
47
Are the rests on the mesial or distal for the posterior abutment teeth (1st and 2nd molars) for a A-P RPD?
They can be mesial or distal but have to be bilateral
48
What clasps are used in the posterior abutment teeth for a A-P RPD?
C clasps
49
What major connector is used for a maxillary A-P RPD?
Horseshoe strap
50
What major connector is used for a mandibular A-P RPD?
Lingual bar
51
Which type of attachments are usually a prefabricated key or keyway with parallel walls, within the contours of the restoration?
Intracoronal
52
Intracoronal attachments produce (mechanical or frictional) resistance against RPD displacement?
Frictional
53
Which attachments create mechanical resistance to displacement through components attached to the external surface of an abutment tooth?
Extracoronal
54
Do extracoronal attachments create (mechanical or frictional) resistance in order to resist RPD displacement?
Mechanical
55
What are the advantages of extracoronal attachments?
Esthetics and mechanical resistance (functional loads are more apically directed and there is improved cross-arch load transfer and prosthesis stabilization)
56
What are the disadvantages of extracoronal attachments?
- Demanding crown prep (space for attachment)
- Vertical height (4-6 mm)
- Laboratory technique (path of insertion)
- Cost
- Wear of components/ maintenance
57
What contraindications are considered when deciding whether or not to place an extracoronal attachment?
- Poor periodontal health
- Poor crown to root ratio
- Compromised endo or restorative conditions
- Compromised manual dexterity
- Inadequate oral hygiene
58
Are the ERA male attachments located inside the RPD or inside the patient's mouth?
Inside the RPD
59
Are the female ERA attachments located in the RPD or in the patient's mouth?
Inside the patient's mouth
60
What is the main reason considered for choosing a type extracoronal attachment?
Vertical height requirement
61
What are the three types of extracoronal attachments that are considered reasonable choices and are widely used?
ERA, SA Swiss anchor/CEKA, Allergro DE
62
What reasons considered when choosing a type of extracoronal attachment?
- Cost
- Simplicity
- Vertical height requirement
- Easy to use
- Easy to adjust or change out parts
63
What is the first step taken when deciding to make an RPD?
Design the framework on a cast
64
What is the second step when making an RPD framework (after designing it on a cast?)
Crown preparation, impression and jaw relation record
65
Why are crowns normally prepped for an RPD?
To create extra space for an occlusal rest
66
After making a provisional for the prepped crown, what is done next?
VPS impression and then jaw relation record
67
What is the 3rd step when making an RPD?
Laboratory prescription; write every feature of the survey crown on the lab slip!
68
What features are described in the prescription?
Rests: location and type
Guide planes: location
Clasp type: retention/ reciprocation
Retentive undercut: location and amount
69
In the 4th step, what should be done before seating the crown in the patient's mouth?
Evaluate the survey crown on the master cast! Does it match? Is it in the right plane? Is the undercut in the right place? survey line? cingulum rest? Remember to add undercuts before seating the crown!
70
What should be done before the final crowns are cemented in the patient's mouth?
Check guide planes and retentive undercuts
71
What is the 5th step (after you have inspected the crown sent back from the lab?)
Seat the crown
72
After the crown is seated the clinican should do what on natural tooth abutments?
Prepare any rests, guide planes, tooth modifications
73
After the rests are made on the natural teeth what is the last step before the RPD framework is made?
Framework impression
74
What type of RPD is indicated for young patients who suffered from post traumatic tooth loss, rapid caries and partial anodontia as well as older patients with compromised medical conditions?
Interim RPD
75
How long should it take for an interim RPD to be completed?
As soon as possible
76
What are some uses for an interim RPD?
- Maintain space
- Re-establish occlusion
- Replace visible missing teeth
- Service during periodontal or implant therapy
- Condition the patient to an RPD
77
Do interim RPDs come in various sizes?
Yes
78
What specific design principles give the interim RPD its retention?
Wrought/ortho wire, ball claspsi; interproximal acrylic struts; surface tension and adhesives
79
What design principles allow for hard tissue support?
Cingulum and occlusal rests, wrought or orth wire rests, ball clasps
80
How far should an interim RPD extend for soft tissue support?
To the pterygomaxillary notch and to the retromolar pad and tuberosity
81
Interim RPDs are an (immediate or not immediate) replacement for teeth removed during a surgical appointment
Immediate
82
How often should the stability and retention of the interim RPD be checked?
Every 3-6 months
83
What materials are used to compensate for tissue changes as a result of post surgical healing of the interim RPD?
Soft tissue conditioners or hard chairside reline materials
84
What types of RPDs are used to aid a patient in making the transition to complete dentures?
Transitional RPDs
85
What type of RPD is made for a patient so that immediate extractions are avoided when some or all of the teeth are hopeless but the patient is not physiologically or psychologically ready for CDs?
Transitional
86
What is a quality that the transitional RPD has that is unique?
Teeth can be added as they are lost and relining is performed as needed.
87
When does a transitional RPD need to be replaced?
This is no absolute time restriction on the use of this prosthesis
88
What type of RPD is used as a vehicle for tissue conditioning?
Treatment
89
Which type of RPD is used to establish a new VDO or act as an occlusal guard to correct or control undesirable oral habits?
Treatment
90
What technique is used in order to repair an RPD? (change a clasp, repair a broken clasp, add teeth, extend a saddle etc)
Make a pick up alginate impression and pour a cast with the RPD in the impression- the RPD is then removed from the cast to make the necessary repairs.
91
Which kennedy classes saddles are treated as altered cast impression trays where a wash impression is made and the rests/clasps are engaged?
Class I and II
92
What is performed in order for occlusion to be finalized?
Clinical remount
93
What are some examples of critical data that is required in order to make an RPD?
- Medical history
- Dental history
- Radiographs
- Exam and charting
- Pre-pros perio, endo, restorative
- Design casts
- Intraoral photos
- Specialty consults
94
If a patient is on a significant number of medications what could be a clinical side effect?
Xerostomia
95
What type of radiograph should be taken if a patient is receiving an RPD?
Full mouth xray (FMX) to see if there are any perio, endo, or restorative issues. A Panorex can also be taken to see if there is any pathology
96
Should the patient have a perio charting prior to the consult?
Yes; to measure attachment loss and pocketing, bleeding, horizontal bone loss, mobility, and vertical defects
97
What considerations should be thought of when evaluating teeth for an abutment?
Periodontal health, endo health, occlusal health and restorative health
98
Can roots be clasped in an RPD?
No
99
If the teeth are mobile then it will be a problem when taking the alginate imression. How is the tooth position maintained in a stable position during this time?
Temporary splint or you can bond composite
100
Should the teeth be tested for any endo problems prior to making the prosthesis?
Yes
101
What type of abutments may require a post and core as well as a survey crown because they require special attention due to the torquing nature of the saddle?
Class I distal abutments
102
Should rests be placed on occlusal contacts?
No; always check occlusion before preparing the rests
103
If there is occlusal trauma or perio mobility on all teeth then what can be done?
Occlusal and periodontal splinting with RPD framework
104
What type of tray should be used for a maxillary complete denture final impression?
Custom triad tray
105
What type of material and tray should be used for a mandibular RPD final impression?
alginate with metal tray
106
Where is the relief wax placed when waxing up the framework?
Under the saddles
107
In the first clinic appointment, of fabricating an RPD, what is accomplished?
Rest preparations, tooth modifications and final impressions
108
In the second clinic appointment, when fabricating an RPD, what is accomplished?
Mandibular framework try in and altered cast
109
In the third clinic appointment, when fabricating an RPD, what is accomplished?
Jaw relations- wax rims, VDO/VDR, facebow, CR, MI, select teeth
110
In the fourth clinic appointment what occurs when making an RPD?
verify articulator mounting, esthetics, phonetics, posterior palatal seal, patient acceptance form
111
After the denture is processed, what occurs?
Delivery of mandibular RPD- fit the RPD and verify occlusion; remount it clinically
112
How many times is the RPD adjusted after it is delivered and what days?
24hrs, 48 hrs, 1 week, 1 month
113
What are some solutions posed to control rotation in Kennedy class I and II RPDs?
Indirect retention, clasps with M rests and saddle extension and fit to soft tissues
114
What is the purpose of the dual impression technique?
Equalize support derived from the edentulous ridge and abutment teeth
115
When is the dual impression technique used?
When there are two unequal support systems which require equalization
116
Is soft tissue (like gingiva and mucosa) displaceable?
Yes
117
Is hard tissue (like enamel) displaceable?
No
118
The broader the coverage of the endentulous ridge the (greater or less) distribution of occlusal load
Greater
119
Should the maximum amount of surface area of the distal extention edentulous ridge be covered in an RPD?
Yes
120
What is the single most important factor in minimizing abutment tooth movement?
Fit of the base
121
Should the tissue be distorted under the fit of the denture base?
No
122
What kennedy classes are indicated for distal extension base stabilization?
- All mandibular distal extensions (class I, II)
- Some long span maxillary distal extensions
- Some long span anterior edentulous ridges (class IV) where the ridge supports the RPD
123
Should depressible, displaceable soft tissue (eg: flabby ridge) have distal extension base stabilization?
Yes
124
How far should a mandibular RPD extend in order to be stable and have retention?
Retromolar pad, buccal shelf and extend fully into the vestibules
125
How far should a maxillary RPD extend in order to be stable and have retention?
Cover the tuberosity, extend into the pterygomaxillary notch and buccal vestibule
126
What comprises the selected pressure technique?
The vestibular border has active tissue contact and the support area is impressed at rest
127
What is fabricated for the selected pressure technique and how far does this extend?
A light cured composite resin tray from triad is fixed to the framework and extended to within 2mm of the normal CD base
128
Which part, the (active or inactive), component of the impression is border molded?
Active- the periphery is border molded
129
The intaglio surface of the tray is relieved to provide space for impression material. This is the _______ component of the impression
static
130
What is the impression material of choice used for the selected pressure technique?
Light or medium bodied VPS
131
Should the framework be fully seated with the selected pressure technique?
Yes- rests have to be fully engaged under finger pressure
132
Should the saddle area be depressed when the impression is setting?
NEVER
133
Where should the pressure be kept if the saddle is never touched when the impression is setting?
Rests and clasp assemblies and border mold
134
The saddle is not depressed while the impression is setting. This ensures that the tissue is recorded in the (active or static) state
Static
135
The altered cast final impression is made with what type of impression material?
ethyl/ isobutyl metacrylate
136
Is the post root canal amputated tooth kept in a removable partial overdenture?
Yes
137
Are the retained teeth attached to the RPD saddle?
No
138
What materials are used to restore the RCT treatment access of the teeth used in a removable partial overdenture?
Amalgam, gold coping and glass ionomer
139
Root canal teeth beneath RPD saddles have several benefits. What are these benefits?
Proprioception, bone preservation (stability and retention)
140
The teeth underneath the RPD saddle of a removable partial overdenture is not connected to the saddle. What components are?
ERA, O-ring or Ball, Zest/ ZAAG or locator abutments
141
Are ERA's easy to change in the office?
Yes
142
What is the wear, in months, of an ERA attachment?
6-9 months
143
What is the vertical height requirement for an ERA attachment?
4.85 mm
144
To what degree of angle width can be used to correct for path of insertion in an ERA?
0, 5, 11, 17
145
Which attachment requires 6.4mm in vertical height (which is alot)
O-ring/ Ball
146
Are O-rings easy to remove and replace?
Yes; the patient can do it
147
Which attachment is least desirable due to its short wear factor?
Ball/O-ring
148
Does an O-ring/ Ball attachment need a parallel path of insertion?
Yes; 10 degrees because they deform at a larger angle
149
Which attachment for implant retained RPD saddles is the most user friendly?
Locator
150
What is the most common RPD?
Kennedy class I
151
What are the three basic components of an RPD?
Metal framework, acryllic saddle and prosthetic teeth
152
Why does a patient usually opt for the use of an RPD?
- Replace missing teeth (esthetics)
- Increase function (mastication)
- Maintain teeth alignment and arch integrity
- Splint periodontally involved teeth
- Transition to a complete denture
- Lower cost alternative!
153
Bilateral edentulous areas located posterior to the natural teeth is known as what kennedy class?
Kennedy class I
154
A unilateral edentulous area located posterior to the remaining teeth is known as what kennedy class?
Class II
155
A unilateral edentulous area with natural teeth remaining both anterior and posterior to it is known as what kennedy class?
Class III
156
A single bilateral edentulous area located anterior to the remaining teeth is known as what kennedy class?
Class IV
157
What determines the path of insertion for an RPD?
The abutment teeth- the external surfaces of the teeth and their relationship (parallelism) defines the path the RPD framework and acryllic follows
158
What is considered the height of contour of a tooth? What is drawn at this area?
The HOC designates the greatest circumference of the teeth. Drawn here is the survey line
159
Is the portion of the tooth apical to or gingival to the survey line retentive or resistant?
Retentive
160
Is the portion of the tooth ,apical to the height of contour, suprabulge or infrabulge?
Infrabulge
161
Does a retentive arm at the infrabulge undercut help with horizontal displacement or vertical displacement?
Vertical displacement
162
Is the portion of the tooth coronal, incisal or occlusal to the survey line known as suprabulge or infrabulge?
Suprabulge
163
Does suprabulge arm placement help with vertical displacement or horizontal displacement (bracing)?
Bracing- resists unwanted lateral stress
164
Is the suprabulge arm conceptually for retention or reciprocation?
Reciprocation
165
What is retention?
Friction and resistance of vertical displacement
166
Which features of an RPD add to its retention?
Clasps and guide planes
167
What is reciprocation?
Bracing an abutment tooth to protect it from lateral stress during the placement and removable of an RPD
168
What part of the RPD aids in providing reciprocation?
Reciprocal clasp arm
169
Which is the most stress relieving because all the forces are supported by the abutment teeth? Quadrilateral, tripod or bilateral?
Quadrilateral clasp placement
170
Which kennedy classes allow for quadrilateral clasp placement?
Kennedy class III and IV
171
Where should the clasps on the dentate side of a Kennedy class II be placed?
As far from each other as possible
172
How many clasps are used in a Kennedy class II?
3; tripod
173
Which is the worst stress reducer? Quadrilateral, tripod or bilateral?
Bilateral
174
What kennedy class uses bilateral clasp placement?
Kennedy class I
175
What feature will significantly reduce the rotational stresses imparted to the abutment teeth?
Proper clasp design
176
What areas are most important for the support of the RPD?
Soft tissue (absolute distal extension) and teeth rests
177
Occlusal, cingulum and incisal rests help with support because they direct the force down the ____________
long axis of the tooth
178
What feature is most important for the stability of the RPD?
Passive fit of the metal framework
179
What determines the occlusion of the RPD?
The opposing occlusion (canine guided, group fxn or bilaterally balanced)
180
How should the surveyor table be placed when surveying the diagnostic cast?
Horizontal or parallel to the horizon because that is how the RPD is inserted into the patient's mouth
181
What is first determined when surveying the dental cast to design an RPD framework?
Path of placement
182
Are all proximal surfaces adjacent to edentulous spaces involved in the path of placement?
Yes
183
How is an undercut found on the diagnostic cast?
The horizontal disc should meet the tooth surface and the barrel is tangent to the survey line
184
How is cast position recorded so that the lab can reposition the cast on their own surveyor?
Tripoding or indexing
185
Should kennedy classification follow the extraction of teeth that may alter the original class?
Yes
186
If a 3rd molar is missing, and is not going to be replaced, is it considered in the classification?
No
187
If a 3rd molar is present, and is to be used as an abutment, should it be considered in the classification?
Yes
188
If a second molar is missing, and not to be replaced, is it considered in the kennedy classification?
No
189
What area ALWAYS determines the classification?
the posterior edentulous area
190
Are the posterior edentulous areas, involved in the classification, considered a modification?
No
191
Can there be any modifications on a class IV?
No
192
The longer the edentulous span the (less or greater) the force transmitted to the abutment teeth?
Greater
193
What shape of the edentulous ridge is excellent and allows for better distribution of force?
inverted U
194
Is a knife edged, narrow or resorbed ridge less favorable for RPD placement than an inverted U ridge?
Yes
195
What are some qualifications that a dentist would want in the alveolar ridge of a patient that they are designing an RPD for?
Large, in height and width, will withstand considerable lateral, horizontal and vertical force
196
What is the function of a major connector?
Cross arch stability; resists displacement of the RPD during function
197
What is necessary for the major connector of the RPD?
Rigidity
198
What does rigidity help the major connector of the RPD do?
Helps to avoid flexure of the framework that will cause stress on teeth and damage to supporting structures and it helps give stability by distributing forces throughout the arch
199
In order for the gingival tissue to have sufficient blood supply, the borders of the maxillary major connector should by how many millimeters away from the gingival margins?
6 mm
200
What is the posterior limit of all maxillary major connectors?
Terminates at or anterior to the vibrating line
201
The major connector should cross the midline at ______ angles for better patient adaptation and biomechanical rigidity
Right; 90 degrees
202
Can a major connector go over the gingiva and onto the teeth?
Yes; full palate
203
How many millimeters wide should the anterior posterior strap major connector struts be?
8 mm
204
What Kennedy classes use a anterior posterior strap?
All classes
205
How long should the posterior strap of the A/P strap major connector be?
8 mm
206
Should the posterior strap of the anterior/posterior strap major connector be at or anterior to the vibrating line?
Anterior
207
Are the struts of the A/P major connector linked at right angles or diagonally?
Right angles- forms a square frame
208
What major connectors can be used to encircle a small torus?
Most can avoid tori; palatal strap, A/P strap and a horseshoe
209
What class most frequently uses a single palatal strap major connector?
Kennedy class III
210
What major connector is the most preferred among patients?
Single palatal strap
211
What is the minimum width needed for the single palatal strap major connector to have sufficient rigidity?
8mm
212
How far from the gingiva should the maxillary single palatal strap start to allow for sufficient blood supply?
6 mm
213
What major connector is indicated in situations where the remaining abutment tooth on either side is a canine or 1st premolar or in cases with severe ridge resorption?
Full palate major connector
214
Is a full palate major connector well accepted by patients?
Yes; it has close adaptation to the palate, thinness and thermal conductivity
215
Which is the least desirable of all major connector designs but is helpful in class IV RPDs with an A/P placement?
U-shaped major connector
216
Which major connector lacks the most rigidity and allows lateral flexure under occlusal loads leading to torquing of the abutment teeth?
U-shaped major connector
217
What is the primary indication for a U-shaped major connector?
A large inoperable torus that extends posteriorly inhibiting placement of a posterior strap
218
The superior border of a lingual bar major connector should be located _____ mm below the free gingival margin
3
219
How long is the lingual bar in vertical height?
4 mm
220
Which is preferred more by patients: a lingual bar or lingual plate?
Lingual bar
221
Is the lingual bar located above or below the floor of the mouth?
Above
222
What is the millimeter requirement for a lingual bar from the free gingival margin to the base of the bar or lingual vestibule?
7 mm
223
Is the lingual plate placed above or below the cingula of the mandibular teeth?
Above
224
Should the lingual plate extend further above the middle 1/3 of the teeth?
No
225
In Kennedy class _______ the linguoplate must have occlusal or cingulum rests to prevent horizontal forces against anterior teeth?
1 and 2
226
What is the most common indication for a linguoplate to be used?
When there is not 7 mm of vertical height from the free gingival margin to the floor of the mouth
227
What major connector is used to stabilize periodontal mobile teeth by splinting in the mandibular arch?
A linguoplate
228
Should a lingual bar or linguoplate be used when there is anticipated tooth loss? (This should be used because teeth can be added to it)
Linguoplate
229
What connects the major connector to all the other RPD components?
Minor connector
230
What is the function of a minor connector?
- Transfer stresses to abutment teeth or underlying supporting tissue
- Support clasp and rest assembly
- connect major connector to all other RPD components
231
Where is a guide plane placed in an RPD?
On the mesial or distal of abutment teeth facing an edentulous space
232
How are guide planes drilled?
Created to follow the contour of the tooth and define the path of insertion
233
What is the size of the guide plane usually?
2-3 mm x 2-3 mm
234
What part of the framework engages a guide plane during insertion and removal of the RPD?
Guide plate
235
Is a guide plate used for mostly retention or resistance?
Resistance- helps maintain arch integrity by anterior posterior bracing action. They also act as retainers due to frictional contact
236
Can guide plates also be used for stability, support and retention?
Yes
237
What connects rests to the major connector?
Minor connectors
238
Are the rest seats created in enamel, restorative materials or dentin?
They are created in enamel and restorative materials mostly
239
Do rests provide horizontal support or vertical support?
Vertical
240
What are the functions of rests?
- Prevent impingement of soft tissues by resisting tissue ward movement
- Direct and distribute occlusal loads to supporting abutment teeth
- Preserve established occlusal relationships
241
Describe the outline of an occlusal rest seat. How wide should the base of the rest seat be?
2.5 mm; should be as long as it is wide and it is a triangle or sppon shape with the apex pointing toward the the center of the tooth
242
How much should the marginal ridge be reduced to allow bulk of metal for strength and rigidity?
1-1.2 mm
243
The floor of the rest seat should be apical to the marginal ridge by how many millimeters?
1.5 mm
244
Should the walls of the occlusal rest seat be parallel, convergent or divergent?
Divergent
245
Why are guide planes created?
To eliminate interferences in the path of insertion
246
Why would the height of contour or survey line change?
To create, decrease, or increase an undercut area
247
Guide planes extend from the ________ to the junction of the middle and coronal thirds
Marginal ridge
248
Changes in the survey line can be accomplished by what 3 methods?
Enameloplasty, composite resin bonding and a survey crown
249
Does moving the survey line occlusally increase or decrease retention apical to the survey line?
Increase
250
Does moving the survey line gingivally increase or decrease retention apical to the survey line?
Decrease
251
Should occlusal rests be made in dentin?
Whenever possible it should not due to recurrent caries. More favorable in enamel
252
Can occlusal rests be made on amalgam or composite?
Yes (for eg it can be made on composite on a tooth devoid of a cingulum)
253
What types of minor connector retaining denture base design is preferred?
Open lattice or ladder
254
The mandibular distal extension should extend at least _______ the length of the edentulous span
2/3
255
The angle formed by the occlusal rest and minor connector should be (more than, equal to, or less than) 90 degrees so that forces can be directed down the long axis.
Less than; if it is more than 90 degrees tooth movement may result
256
Is it important to inform and obtain consent from the patient ahead of time if there is a chance of perforation (when making a rest seat) through an existing restoration that may need repair (eg: crown)?
Yes
257
Which is preferred: a cingulum rest or an incisal rest?
Cingulum; more esthetic and less tendency to tip the tooth
258
Where is an incisal rest placed?
At the incisal angles of anterior teeth
259
Is an incisal rest favorable?
It is the least desirable placement of a rest seat due to esthetics and possibility of tooth movement
260
What are two types of manufactured extracoronal attachments?
Clasps, dalbo, ERA etc
261
Intracoronal direct retainers have parallel walls to create a _______ which limits movement and resists displacement
Frictional contact within the crown
262
What are the six requirements for clasp retainers?
retention, reciprocation, bracing, adequate encirclement, support, and passivity
263
What is resistance to vertical dislodging forces and is a requirement for clasp retainers?
Retention; apical to the height of contour
264
Are the retentive arms of a clasp flexible or rigid?
Flexible
265
What is the concept that describes resistance to horizantal forces applied to a tooth by an active clasp during insertion and removal?
Reciprocation
266
What area of the tooth are used for the placement of stabilizing non-retentive reciprocating clasp components?
Coronal to the HOC
267
What is resistance to horizontal components of masticatory forces?
Bracing
268
What components of an RPD are important for bracing it during mastication?
minor connectors, guide plates, and clasp arms
269
What aspect of a clasp prevents horizontal tooth movement away from the confines of the clasp assembly and assists in bracing?
Adequate encirclement
270
Adequate encirclement of the clasp should be (more than, equal to or less than) 180 degrees at the largest circumference of the tooth?
More than
271
What concept describes resistance to vertical seating and occlusal forces?
Support
272
What aspect of the clasp is the most important in providing support?
Rests
273
What is the quality of inactivity or rest assumed by the teeth, tissues and prosthesis when a RPD is in place but not under masticatory pressure?
Passivity
274
What part of the retentive arm is located in the undercut area of the tooth?
The terminal 1/3
275
The clasp tip ______ upon insertion and removal as it passes over the insertion line.
Flexes or deforms; this is crucial
276
The (shorter or longer) the clasp length, the more flexible
Longer
277
The (smaller or bigger) the clasp diameter the more flexible.
Smaller
278
Which clasp shape cross sectional form is universally flexible?
Round
279
Which clasp shape is flexible in one direction only (away from and back to the tooth surface?)
Cast half round
280
As the retentive arm engages the height of contour, what part of the clasp should contact the tooth to stabilize it during this deformation.
Reciprocal arm
281
What clasps are considered suprabulge clasps?
Akers, circlet, or C clasp
282
Does the reciprocal arm of a suprabulge clasp cross the survey line?
No
283
Where does the retentive arm originate in a suprabulge clasp?
Minor connector of the abutment tooth
284
An embrasure clasp is used in a _______ with no modification spaces on the opposite side of the arch
Kennedy class II or III
285
Do embrasure clasps require aggressive tooth preparation?
Yes
286
What does an embrasure clasp consist of?
Two C clasps originating from a common minor connector
287
An infrabulge clasp (crosses or does not cross) the height of contour when the RPD is fully seated.
Does not cross- it is only crossed during insertion and removal
288
What are some examples of infrabulge clasps?
I bar, modified T bar and all bar clasps
289
The retentive clasp of an I bar is always on the (lingual, facial, mesial or distal)
Facial
290
What are the reciprocating elements of an I bar clasp?
The minor connector, mesial rest and distal guide plane
291
What clasp is usually used in a Kennedy class III design?
C clasps
292
A Kennedy Class III RPD is known as _______ because its support are mainly the remaining teeth.
Tooth bourne
293
How many clasps are used for a kennedy class III?
4 clasps (K class +1)
294
What is the most common maxillary major connector used for a Kennedy class III?
Palatal strap
295
How many clasps are used in a Kennedy class IV?
4 clasps (breaks the rule)
296
The (shorter or longer) the edentulous space, the more potential for rotation around the fulcrum line and the more need for indirect retention
Longer
297
What are the most common maxillary major connectors used for a Kennedy class IV?
horseshoe or A-P strap
298
A clasp is an extracoronal retainer. An extracoronal attachment is what?
Retention via components attached to the external surface of abutment teeth which interlock with another component in the RPD
299
What are some advantages of infrabulge clasps?
- Minimal tooth contact
- Precise placement of retention contact
- Minimal interference with natural tooth contour
- Passive functional movement of a distal extention
- More esthetic; less display of metal
300
What type of lever may result in tooth mobility and loss?
Class 1 lever
301
Which kennedy classes have the least potential for rotation and destructive forces?
Kennedy class III and IV
302
Which kennedy class has the greatest potential for rotation around a fulcrum line since there is no tooth support posteriorly?
Kennedy class I
303
What is the fulcrum line?
the axis of rotation and passes through the two most distal rests (or most anterior rests in a class 4)
304
In what direction is the abutment tooth moved when there is a first class lever effect?
Distal and superiorly (like a crowbar)
305
What clasp should never be used on a distal abutment of a distal extension RPD with a distal rest?
C clasp
306
What are the problems when using a C clasp with a distal rest on kennedy class I and II?
- Formation of a class 1 lever
- Potential for distal rotation of clasp
- Potential to compromise the abutment teeth
307
What solutions can be offered in order to eliminate a class 1 lever effect in a Kennedy class I and II?
- Control rotation by indirect retention or a better fitting saddle
- Put a different clasp (not a C clasp)
308
What clasp engages the .02 undercut on the facial and has a cast reciprocal arm on the lingual for kennedy class I and II?
Wrought wire
309
How does a wrought wire clasp reduce sagittal plane rotation in a class 1 and 2?
It is a more flexible clasp so it is easier to disengage and cause less stress to the tooth- limits torquing and rotation
310
What wire is used in a wrought wire clasp?
18 gauge round wrought wire
311
When there is a loading force on the wrought wire clasp, the arm moves _______ to direct the distal torquing force
Occlusally
312
What are the disadvantages of a wrought wire clasp?
- Unnecessary distal torque
- May be distorted by patient manipulation
- May distort with function and not engage the tooth
313
We want a ______ lever; which means that the force, rotation and occlusal load are on the same side
Second class
314
A __________ rest on a distal abutment creates the least force on the abutment
Mesial
315
A mesial rest with either ________ or a ______ clasp exerts the least force to abutments
Wrought wire or I bar
316
There is (decrease/ increased) abutment movement when indirect retainers are removed?
Increased
317
When the fulcrum is moved forward (mesial instead of distal rest) the resistance arm changes and there is a (higher/ lower) engaging effect.
Lower- you change from class 1 to class 2 lever
318
A modified RPA has what types of components?
Mesial rest, distal guide plate, 19 gauge cast round wire clasp
319
A modified RPA engages what undercut?
Mesiofacial .01"
320
A wrought wire clasp engages what undercut?
Mesiofacial .02"
321
A reverse C clasp has what components?
Mesial rest, distal guide plate, retentive and reciprocation clasps
322
What undercut does a reverse C clasp engage?
Distofacial .01"
323
What undercut does an I bar usually engage?
Midfacial .01"
324
What undercut does a modified T bar usually engage?
Distofacial .01"
325
What design concept was developed in order to prevent rotation around the fulcrum line?
Indirect retention
326
What kennedy classes absolutely need indirect retention?
Class 1 and 2 and sometimes 4
327
Where is indirect retention placed?
Occlusal or cingulum rests anterior to and perpindicular to the fulcrum line- as far from the fulcrum line as possible
328
Indirect retention helps to avoid the __________ effect which pushes anterior teeth anteriorly
Inclined plane effect
329
Does indirect retention limit rotation of the RPD in the superior direction or inferior direction?
It limits superior displacement
330
What aspect of the RPD is controlled through saddle fit to tissue?
Inferior displacement
331
Does a plate alone offer enough retention to be considered an adequate indirect retainer?
No; there must be an associate rest beneath the plate or at the terminal end to function as an indirect retainer
332
What clasp is the first choice considered for a distal extension in a Kennedy class 1 and 2?
I bar- infrabulge class
333
How are the bar clasp arms classified?
By the shape of the retentive tip
334
What are the indications for using a bar clasp?
- Tooth-supported RPD
- Modification spaces in a Kennedy class II
- Distal extension cases with appropriate undercut (class 1 and 2)
335
A bar clasp is used on an abutment tooth with a .01" undercut in the cervical 1/3 that can be accessed from the (occlusal or gingival) aspect
Gingival
336
When should a bar clasp not be used?
- Severe buccal or lingual tilt
- Soft tissue undercuts within 3mm of the free gingival margin
- Shallow vestibule (minimum 3-4 mm)
- Prominent buccal frenum
337
What is the minimum amount of buccal vestibule necessary in order to use a bar clasp?
3-4 mm
338
When there is an occlusal force on an I bar, in what direction does the clasp move to ensure a class II lever?
Mesiogingival
339
Where is the minor connector of an I bar located?
Mesiolingual embrasure
340
The mesial rest directs the center of rotation of the clasp _________ disengaging the tooth during functional loading
Mesiogingivally
341
What two aspects, necessary for a clasp to function, does the minor connector of an I bar provide?
Adequate encirclement and reciprocation
342
What do the mesial rests of an I bar provide (this is a necessary trait for a clasp to function)?
Vertical support
343
The undercut should exist (above/ below) the guide plane, of an I bar, to permit disengagement of the proximal plate under functional loading of the saddle.
Below
344
How thick is the proximal guide plate of an I bar?
1-1.5 mm
345
The proximal guide plate can extend lingually to connect with the ______ of the mesial rest to provide encirclement
Minor connector
346
What two major aspects does the proximal plate provide? (necessary for RPD fxn)
Reciprocation and encirclement
- helps with retention due to parallelism
- provides guidance
- reunite and stabilize the arch
- distributes occlusal forces
347
Is an I bar placed in the distobuccal undercut?
No because it will not disengage under function (should be placed in the midfacial or slightly mesiofacial)
348
When should a suprabulge clasp be used in a Kennedy class 1 and 2?
- When there are soft tissue or bony undercuts apical to the free gingival margin in the first 3 mm of tissue
- Shallow vestibule
- Patient factors (medical/physical conditions)
349
What type of wire does a modified RPA have?
19 gauge cast round wire retentive arm
350
Which suprabulge clasp is the first choice in a kennedy class 1 and 2?
modified RPA
351
Which clasp is considered the most flexible?
RPW
352
Which clasp is difficult to keep in contact with the tooth surface?
RPW
353
Where does the retentive arm of the reverse C clasp originate from?
The mesial rest to engage the .01 DF undercut
354
If a modification space is present on the dentate side of a class 2 then which teeth should be clasped?
The teeth adjacent to the space
355
If no modification space is present on the dentate side of a kennedy class II then what teeth should be clasped?
The most anterior and posterior (as far away from each other as possible)
356
Final impressions for RPD frameworks are made with what material and what type of tray?
Metal perforated trays and alginate
357
Why are metal trays used?
Because of their rigidity
358
What is the function of the work authorization or prescription?
- Instructions to the lab technician
- Protects the public from illegal practice of dentistry
- Protective legal document for dentist and lab technician
- Completely delineates the responsibilities of the dentist and the lab technician
359
What type of acrylic retention is preferred?
Open lattice or ladder
360
What steps are involved in fitting an RPD framework?
- Evaluation of the framework prior to the patient's visit
- Clinical fitting
- Adjust framework
- Repolish adjusted surfaces
361
The acrylic retention of the framework should have ________ on the distal extensions
Tissue stops
362
How are the internal metal surfaces checked, for hard and soft tissue interference, during the clinical fitting of framework?
Disclosing wax or occlude spray
363
Should the distal extension be depressed with finger pressure during clinical fitting of the framework?
No there is always movement; the frame is unsupported due to the absence of a saddle
364
How should interferences in the metal framework be adjusted?
Composite finishing burs on high speed or green stones on slow speed
365
What specific composite finishing burs should be used to adjust the metal framework so it is stable, flush with teeth and engaged?
4 round, 6 round, 274 finishing
366
Which exerts more force on abutment teeth? An adjusted RPD framework or an unadjusted RPD framework?
Unadjusted RPD framework
367
What are the common problems associated with the clinical fitting of the framework?
- Guide plates
- Origin of circumferential clasps
- Under embrasure clasps
- Interproximal projections of lingual plates
- Beneath rests
368
Should the occlusion be supported by occlusal rests or any part of the framework?
No; unless the RPD is specifically designed to change the VDO or occlusal plane
369
Should a framework create new occlusion, working side contacts, non working side contacts, or protrusive contacts?
No it shouldn't have interferences of any kind
370
How are interferences on the framework recognized?
Articulating paper
371
How thick should metal framework components be?
1- 1.2 mm
372
Should the occlusion be adjusted with both maxillary and mandibular frameworks in the mouth or should they be adjusted separately?
Adjust first independently and then with both inserted
373
How are metal frameworks re-polished?
Finishing stones, hard rubber wheels, and points (tripoli and rouge)
374
What degree teeth match the residual dentition and are usually used in the RPD framework?
10-22 degree teeth; 0 degree teeth are not used in the RPD arch
375
The RPD occlusion is determined by what?
The occlusion of the opposing arch (if it is a denture then it is bilaterally balanced non-working balance)
376
How can protrusive balance be achieved when adjusting an RPD to the occlusion of a maxillary CD?
Balancing ramp
377
Should unerupted teeth be removed in saddle areas?
It depends on the amount of overlying bone, history of the tooth, evidence of pathology
378
Are maxillary tori more common in women or men?
Women
379
Is surgery necessary for a maxillary torus?
Most major connectors circumvent but it may be required
380
Are mandibular tori usually bilateral?
Yes
381
Are mandibular tori more common than maxillary tori?
No; maxillary are more common in 20-25%
382
Should mandibular tori be removed?
Yes; it compromises in design, rigidity and placement of major connector. It is very thin, easily traumatized and should be removed
383
Are maxillary exostoses or undercuts more common than mandibular?
Yes
384
Should maxillary and mandibular undercuts be removed?
Yes; if in critical base areas of RPD saddle extensions then they should be removed h/o path of insertion or design may compensate for some undercuts
385
What is the treatment of choice for maxillary tuberosities?
Compromises vertical space so they should be reduced
386
If a labial frenum is at the crest of the ridge and hypertrophic then what should be done?
Frenectomy
387
Evaluation for most pre-prosthetic surgery is best accomplished how?
By putting diagnostic casts on a surveyor while designing the RPD
388
What material is predominately used for a framework?
Cobalt-chromium or nickel chromium
389
What are the advantages of cobalt chromium alloys?
- Higher strength
- Fatigue resistance
- Lighter weight
- Lower cost
390
Which material has the high biocompatibility and low cytotoxicity (used in implants)?
Titanium
391
What are some advantages of titanium?
- Low weight to volume
- High strength to weight
- High fatigue resistance
- High corrosion resistance
392
What are some examples of cobalt-chromium alloys and what is their composition?
Vitallium, Nobilium, Wironium; 30% Cr and 60% cobalt
393
Which has the highest density: gold, cobalt chromium, nickel chromium and titanium?
Gold
394
Which has the lowest density: gold, cobalt chromium, nickel chromium and titanium?
Titanium
395
Which material requires special expensive equipment to make the framework?
Titanium
396
Maxillary frameworks will have improved retention if the weight is (higher or lower)
Lower
397
Which has the highest modulus of elasticity: gold, cobalt chromium, nickel chromium and titanium?
Cobalt chromium
398
Which has the lowest modulus of elasticity: gold, cobalt chromium, nickel chromium and titanium?
Gold
399
Which requires less retention because it is twice as stiff as the other materials?
Cobalt chromium
400
Which materials are the easiest to adjust: gold, cobalt chromium, nickel chromium and titanium?
Gold and titanium
401
Which is the easiest to solder: gold, cobalt chromium, nickel chromium and titanium?
Gold
402
Which materials are the most cost effective: gold, cobalt chromium, nickel chromium and titanium?
Co-Cr and Ni-Cr
403
Which is the most expensive material: gold, cobalt chromium, nickel chromium and titanium?
Gold
404
Why is nickel less used?
Allergy
405
Why is beryllium not grinded in the lab or chairside?
Toxic
406
If a patient is still concerned that there are red cadmium salts in the acrylic (even though it was all removed 20 years ago) what can be recommended?
Heat-processed clear acryllic
407
Hand articulation of casts is acceptable in what kennedy classes?
Class III and IV because there are bilateral anterior/posterior occlusal stops that are clear and solid
408
Which kennedy classes require a wax rim and record base (made with PVS and Alluwax)
Kennedy class 1 and 2
409
What should be placed below the framework first (if there is no triad base) before the wax rim is built up?
Wax
410
What must seat completely before making the wax rim for the RPD?
Rests
411
The wax rim should be cut once VDO is recorded. What stops should be preserved?
One in the anterior and one in the posterior
412
Which cast is mounted using the PVS index at the VDO?
the mandibular cast
413
Do lateral path of placement struts engage the facial surface?
No
414
Name the steps in order for how to create an RPD
1) treatment plan
2) study casts and design
3) final impressions
4) fit and correct framework
5) bite registration
6) wax rims and set teeth
7) deliver
415
What connects the RPD to the existing dentition?
Abutment teeth
416
What two aspects are most important for the retention of the RPD
Clasps
| Guide planes/ plates
417
What two parts of an RPD are most important for support?
Tooth rests and soft tissue extension
418
The occlusion of an RPD is considered _______ because it depends on the occlusion of the opposing arch
Harmonious
419
What is instrument on a surveyor is used to figure out path of insertion and cast orientation?
Stylus
420
Are base metals more rigid than gold?
Yes
421
Which has more friction associated with it: metal to metal or metal to enamel/ porcelain
metal to metal
422
The border of the maxillary major connector should be 6 mm away from and (perpindicular or parallel) to the gingival margins?
Parallel
423
Why should maxillary major connectors cross the midline at right angles?
Better patient adaptation (tongue acceptance) and biomechanical rigidity
424
A single palatal strap is indicated for what situations?
situations with bilateral tooth-support and posterior edentulous spaces
425
When is a full palate major connector indicated to be used?
In situations where the remaining abutment on either side is a canine or 1st premolar and in cases with severe ridge resorption.
426
Where is a lingual bar major connector located?
Above the floor of the mouth and as far as possible below the gingival margins
427
Guide plates act as ______ secondary due to frictional contact with parallel guiding planes
Retainers
428
The deepest portion of an incisal rest is ______ to the incisal edge
Apical- the incisal rest is a rounded notch
429
Are the keyways in the crowns or in the RPD?
Crowns
430
What components are most important for bracing the RPD (stabilizing it during horizontal masticatory forces)
Minor connectors, guide plates, and retentive/ reciprocal arms
431
Is contact continuous or discontinuous with adequate encirclement?
It can be either
432
Which of these clasp shapes "rolls" onto the tooth surface? (round or cast half round)
Round
433
What kennedy classes predominately use an embrasure clasp?
Kennedy class II and III without modification spaces on the opposite side of the arch
434
What are the reciprocating elements of an I bar clasp?
Mesial rest, minor connector and distal guide plane
435
The parts of an RPD (like clasps) that resist displacement of the RPD away from the basal seat tissues provides _______
retention
436
Secondary retention of an RPD is provided by what RPD aspects?
Intimate frictional fit of the minor connector contact to guiding planes, denture bases to soft tissue and Major connectors in maxillary arches (surface tension)
437
Rotation around the (frontal or sagittal plane) causes lever forces
Sagittal
438
In a first class lever the fulcrum line is located ______ the force and the resistance (rotation) to that force
Between
439
In a second class lever, the force, fulcrum line and resistance to the force (rotation) are on (opposite sides or the same side)
Same side
440
What part of mesial rest clasps are important for reciprocation?
Minor connector and distal guide plates
441
What part of the mesial rest clasps is important for retention?
Clasp
442
Is the tooth engaged or disengaged during functional loading?
Disengaged
443
The minor connector of the mesial rest clasps provide ________ and ___________
reciprocation and encirclement
444
The proximal guide plate of the mesial clasps has to be _____ mm thick and _______ at the gingival tissue so that it is relieved
1-1.5 mm and highly polished
445
Proximal plates in mesial rest clasps provides _________ and ____________
reciprocation and encirclement. It also provides horizontal stability, stabilizes the arch, retention, and guidance and it distributes occlusal forces
446
What are the most important uses for an Interim RPD?
Replace visible missing teeth and service during perio and implant therapy
447
Ball clasps offer _________ and ________ hard tissue support of an interim RPD
interproximal and marginal ridge
448
There are _________ rests in acrylic for hard tissue support in an Interim RPD
Cingulum and occlusal rests
449
The soft tissue support in interim RPDs should extend to what part of the maxilla and mandible?
Pterygomaxillary notch and retromolar pad and tuberosity
450
Which RPD is used for tissue conditioning, as a split and as an occlusal guard?
Treatment
451
How are relines for Kennedy class I and IIs done?
Treated altered cast impression trays, wash impression is made, rests/ clasps engaged with the teeth out of occlusion
452
What is done in order to finalize the occlusion?
Clinical remount
453
What is the spider?
An RPD on one tooth with two clasps- we don't use this because it is easily swallowed
454
Which attachment has 3 retentive sleeve choices?
Allegro DE
455
Which path of placement RPD has passive rotational placement so it requires no reciprocal element?
Lateral
456
The Lateral path rpd is first inserted on what side? Fully dentate or the edentulous side?
Fully dentate - it is removed from the edentulous side
457
What is the only retention on a P-A rotational path rpd?
Mesial plate on the molar
458
Which type of rotational path rpd requires no reciprocation because there is no horizontal force on the abutment tooth?
P-A path of placement
459
What are the major reasons to do an altered cast or selective impression technique?
MANDIBULAR CLASS 1 AND 2, depressible displaceable soft tissue and when there is a need to define peripheral extensions for any RPD
