Prosthodontics Flashcards
(213 cards)
1
Q
what is design transfer?
A
conveying the outline of the proposed prosthesis from the diagnostic cast to the master cast
2
Q
importance of the surveyor?
A
- height of contour
- undercuts
- draw the clasps
- draw the connectors
3
Q
tripoding is important for ?
A
path of insertion
4
Q
what does each color represents?
A
- Brown: metallic portion
- Blue: resin finish lines
- Red: retentive areas and rests
5
Q
what is waxout or blockout?
A
blocking the udesirable undercuts with wax
6
Q
what are the 3 types of blackouts?
A
- Parallel
- Ledging (shaped)
- Arbitrary
7
Q
what is the parallel blockout?
A
putting wax and trimming it parallel to the path of insertion
8
Q
what is the ledging blockout?
A
- on the primary abutment
- In relation to a connector or clasp
- from the tooth surface extending the lower border
9
Q
what is the arbitrary blockout?
A
- After finishing the other types of blackouts if there is any undercut or something we don’t need in the design for ex: soft tissue
- doesn’t have to be parallel to the path of insertion
10
Q
define relief?
A
it is placing a wax sheet in strategic areas using a wax spacer
11
Q
relief importance?
A
- Create a small space between the framework and cast or soft tissues
- relief tori and tender areas
- the most cool relief is associated with denture base.
12
Q
what is beading
A
we do it in the maxillary by scraping for not more than 1 mm depth to limit the wax extension but we don’t do it on the mandibular because we don’t have a palate
13
Q
what is the purpose of duplication?
A
- to preserve the cast from breaking
- To allow an investment (refractory) cast to be formed for framework fabrication
14
Q
list the duplicating materials:
A
- colloidal ( heat=gel into liquid)
- sillicon material
15
Q
if you used low heat alloy (gypsum bonded investment) which type of investment material you will use?
A
- reversible hydrocolloid with a water base
- burnout at 704
- like gold IV and ticonium ( cobalt -nickel - chromium ) which is the mostly used
16
Q
if you used high heat alloy which type of investment material you will use?
A
- phosphate bonded investment and glycerine base colloid
- burn out at 1037
17
Q
what is the importance of beeswax?
A
because the refractory cast is porous in nature everything we put will be absorbed so we dip it in the beeswax for 15 seconds to ensure smoothness.
18
Q
before the actual waxing begins we take the measurements of the cast using ?
A
boles gauge
19
Q
what is the most critical part of the transfer ?
A
the position of the clasp tip
20
Q
what are the differences between casting waxes and plastic pattern?
A
*casting waxes:
- No specifications
- Maximum flow 10% for 35
- Minimum flow 60% for 38
*Plastic pattern
- Mostly used
- Require tacky liquid before placing it
21
Q
Note:
A
when waxing the framework for a gold casting we use a heavier wax pattern because gold is lighter and we need heavier pattern to allow the gold to flow
22
Q
what is the diameter for sprues?
A
3.5-4mm
23
Q
what are the characteristics of a sprue?
A
it should be uniform without any angle because then it will block the flow
24
Q
spring can be classified into?
A
- single
- multiple ( when the pattern is long)
24
sprue consists of?
sprue former
reservoir
24
what will happen if there is constrictions in the sprue?
internal deformation and inclusion casting
25
when do we use the axillary sprues?
- Long span
- Heavy Pontic
- 1/3 or 1/4 the size of the main sprue
26
what will happen if there is insufficient burnout?
- Insufficient mold expansion
- short casting
27
what will happen if there is over burnout?
- breakdown and destruction of the mold
28
burnout purposes?
- drives off the moisture
- melt the wax and create spaces
- expand the mold to compensate the alloy contraction
29
what is casting?
introducing the molten metal
30
how the framework is divested?
aluminum oxide
31
advantages of CAD CAM in partial dentures?
- reduce lab steps
- No need for refractory cast
- Automatic blockout and surveying
32
what are the materials used in CAD CAM
cobalt chromium
titanium
poly ether ether ketone
33
advantages of PEEK
- mechanical stability
- chemical stability
- High temp resistance
- biocompatible
34
when do we use the precision attachment ?
when we have a big load on the prosthesis
35
what is the advantage of precision attachment ?
fixation
stability
retention
36
precision attachment is not used on a regular basis but in which Kennedy classification we can use them?
1 and 2
37
what are the synonyms for precision attachment ?
internal att
frictional
slotted
key and keyway
parallel
38
another synonyms of female att?
- crypt
- slot
- Matrix
- Key way
- Receptacle
39
another synonyms of male att?
- Key
- Patrix
- Insert
- Flange
- Fitting
40
method of fabrication and fit tolerance
- prefabricated which if there is an error in the casting process it will not fit
- semi-percison att lab or custom made which have a space for movement
41
what are the classification of attachments?
-based on method of fabrication and fit tolerance
- based on primary abutment
- based on joint stiffness
- based on the geometric configuration and design of the attachment
42
based on primary abutment
- extra coronal ( outside the contour of the retainer)
- intra coronal (within the contour of the tooth)
43
based on joint stiffness
- Rigid
- Resilience ( non rigid)
44
characteristics of intra coronal precision att:
- prefabricated
- within the normal contour of the tooth
- applied occlusal forces are closed to the axis of the abutment
- require a box
- height, buccolingual, mesiodistal 5 mm
- rigid , doble abutting is preferred where the adjacent tooth to the abutment os crowned
45
intra coronal precision att retention:
- Frictional
- mechanical
- combination
46
what are the applications of intra coronal attachment
-Retainer for removable
- Connector for fixed
47
advantages of intra coronal att?
- eliminate food stagnation
- Occlusal forces are distributed close to the long axis of the tooth
- Reduced bulkiness
- Self cleansable
48
disadvantages of intra coronal att?
- Extensive preparation on the abutment tooth = pulp devitalization
- Adequate crown length and small pulp size
- Hrad to fabricate
- Handling by patient is more difficult
49
characteristics of extra coronal precision att:
- For distal extension
- Kennedy class I and II
- Double abutments are preferred
- We need inter occlusal space 5 mm
50
advantages of extra coronal att?
- Reduced tooth loss
- Reduced pulp devitalization
- easier insertion
- Normal tooth contour is maintained
51
disadvantages of extra coronal att?
- Lack of occlusal stability
- Improper occlusal force distribution
- Maintain of hygiene is difficult
- positioning the artificial tooth in the attachment region is more difficult
52
for the clasp assembly
- Support (rest)
- Retention (retentive arm)
- Stability ( reciprocal arm)
53
advantages of PA from clasp retained
- Esthetic
- Overloading is prevented
- functional load is equal
- efficiency of retention is not affected by the contour of the abutment tooth.
- food impaction is prevented
- rotation is prevented
- retention , reciprocation, support are all within the component
54
disadvantages of PA from clasp retained
- Cost
- Long clinical time
- Extensive preparation
- Wear and loss of the retentive component component
55
indications of PA from clasp retained
- Removable retainer
- Stress breaker
- Periodontal involvement where rigid FPD is contraindicated
- movable joints
- Divergent abutment with high survey line
56
which one is preferred for distal extension?
resilient extra coronal att because of less stress
57
where are the retentive areas?
just under the surveyor line where the retentive arm will be placed
58
on which position the cast should be placed? and what do we need to check?
- Zero tilt
- we need to check the undercuts, parallelism of the proximal surface of the abutments and the parallel path of insertion, also check the guiding planes
- if we are not able to detect we can tilt AP or lateral .
- If there are no undercuts and the guiding planes are not parallel we have to prepare the abutments.
59
how can we prepare the abutments?
- minimal invasive treatment
- Surveyed crowns
60
what is the minimal invasive treatment ?
- rest seat occlusally or lingually
- guiding plane by removing only 1.5 mm
- Composite on the labial surface of the abutments
61
what is surveyed crown?
is a restoration that have retentive contours, parallel guiding plane and rests within the crown
62
when do we use the partial coverage crown (three quarter crown)?
when the buccal or labial surface of the abutment is sound and the retentive undercuts are acceptable
63
if you are using full veneers or PM ?
adding or reducing porcelain
64
what are the indications of surveyed crowns?
- undesirable tooth contour and enamel modification can't be done
- Re establish proper occlusal plane
- Restore a cavity or badly broken tooth
- rests for anterior teeth
- correct the angulation
65
what is the treatment sequence if we want to use surveyed crowns?
- Diagnosis and surveying
- RPD design
- Surveyed crowns
- RPD fabrication
66
how much should we reduce for the surveyed crowns?
2mm
- 1.5 for the rest seat
- 0.5 for metal thickness
67
which type of recording jaw relationship we use for surveyed crowns?
- Interocclusal record
- Occlusal rims
and it should be recorded at the desired VDO
67
what is the polished surface ?
- everything polished including the buccal and lingual
- Non articulating parts of teeth (buccal & lingual) AND the buccal, labial, lingual, and palatal parts of the denture base material.
68
what is the intaglio/internal/impression surface
- it is the surface attached to the mucosa
- Denture part in contact with the denture bearing area.
69
occlusal surface
-occlusal and incise edges
-Articulating surfaces of teeth that make contact during functional and parafunctional movements
70
how many visits are needed for conventional dentures:
1- Preliminary impression
2- Definitive
3- Registration
4- Try in
5- Insert
71
how many visits for digital dentures:
1- impression
2- Try in (may and may not)
3- Insert
72
the first two visits are to create which surface ?
impression surface
73
the third visit is for ?
occlusal and polished surface (VD, CO, aesthetics)
74
what is VD?
vertical distance between any 2 points one in the maxilla and one in the mandible
75
describe the resorption in the mandible:
-Anterior: labial
-premolar: equal
- posterior: lingual
-ridge in the anterior will be placed lingually and the ridge in the posterior will be placed bucallly
76
describe the resorption in the maxilla:
- Labial and buccal resorption
- the ridge will be placed palatally
77
what are the Registration Visit Objectives?
- Support and esthetics
- Vertical dimension and centric relation (inter maxillary relation)
- Teeth Selection according to the selected
occlusal scheme
78
what is the fox plane ?
- Ala-tragus (campers line)
- Inter-pupillary
79
what is occlusal rims?
occluding surfaces fabricated on interim or final denture bases for the purpose of making maxillomandibular relation records and arranging teeth
80
what is occlusal rims?
- wax rims+baseplate
- Similar to custom tray with some differences: extension (in the custom tray we want to be 2mm short for border molding but here we don’t do border molding) we do full extension to make it stable
81
what are the materials used for baseplate?
- Shellac (thermoplastic)
- Autopolymarization
- Light cured (mostly used)
- Wax baseplates
* Remember that the baseplate is just an interim stage it will not be in the final denture
82
Shellac (thermoplastic)
+ cheap, easy to adapt
- brittle, distort easily
83
Autopolymarization
+ Cheap, technician familiar with.
- Handling problems, needs to block undercut, may damage the cast
84
Light cured
+ Easy to make, quick.
- same as in Auto, problems of wax adherence, more difficult to polish
85
Wax baseplates
+ cheap, easy to use, good interocclusal space for setting.
- easily distorted.
86
how do we determine the form and contour of the dentures ?
- Occlusal plane
- Arch form
87
what are the dimensions of the occlusal rims ?
max:
- Anterior: height 22, width 8
- Posterior: height 18mm, width 10mm
man
- Anterior: height 18, width 8
- Posterior: height 2/3 of the retromolar pad, width 10mm
88
what do you know about Biometric technique
- Replacement upper teeth be placed in pre-extraction
- Fixed points of measurements : remnants of the lingual gingival margin
- help compensate for the facial changes after tooth loss
89
what is centric relation?
- maxillomandibular relationship, indepents of teeth where the condyle is in its anteriosuperior position against the articular eminence , the mandible will be restricted to a purely rotary movements and it is a repeatable reference point.
- Record anterior posterior and mediolateral surfaces
- when the condyle articulate with the thinnest avascular portion of the disk
- Repeatable
90
what is maximum intercupsation ?
independent of the condyle, when the teeth are occluding maximumly
91
what is the importance of the occlusal stop?
- prevent the jaw form closing further
- maintain the vertical height of the lower face
92
what is VDO?
distance measured between any two points on the patients face when the patient it as occlusion
93
CR is used in ?
edentulous and partially edentulous it depends on the teeth contact
94
which test is the most used for VD?
physiological (free way space)
95
what is the space required to have a good VD at rest?
2-4 mm in premolar region
96
what is the importance of phonetics ?
-The patient is instructed to pronounce the sound (s) to determine the approximate closest speaking space
-No average closest speaking space: varies from 0-10mm
-Best performed at the try in with teeth
97
For edentulous your guideline is to put the incisal edge at which level ?
0 mm or within 1 mm not more than that
98
which type of test depends on the patient comfort?
Neuromuscular
99
which type of test is more applicable for research ?
biting force
100
incisive papilla to the max and man?
6 mm from max
4 mm from man
101
what is the face bow record?
- an instrument used to record the spatial relationship of the maxillary arch to some anatomic reference point or points and then transfer this relationship to an articulator; it orients the dental cast in the same relationship to the opening axis of the articulator; customarily the anatomic references are the mandibular transverse horizontal axis and one other selected anterior reference point
- Relate the max to the hinge axis
102
which type determine the true position of the terminal hinge axis?
Kinematic
103
imp note:
Use of facebow is not essential for the success of CDs, it could be needed in fixed prosthodontics but for CD it is not that significant
104
what are the steps for complete denture procedure?
1- Maxillary rim
2- Mandibular rim
3- VD
4- CR
5- Grooves for CR registration
6- face bow?
7- Teeth selection
105
what type of material we can use for bite registration ?
- PVS
- Zinc oxide eagunoul
- wax (Alu wax)
- Impression compound
106
what is overjet and what is the normal range ?
horizontal distance between the labial upper rim to the labial lower rim , 1-2mm
107
what are the techniques to guide the mandible in CR?
Active (unguided)
passive (guided)
108
list the active unguided methods:
- Using the tongue
- Protrusion and recursion of the mandible
- Exclusive movements (gothic arc tracer)
- swallowing
109
list the passive guided methods:
- Relaxation of the temporalis and masseter muscles
- Chin point guidance
- Downs's bimanual manipulation
110
which method is the best for positioning the mandible in CR?
using active and passive by trying to push the mandible backward and ask the pt to touch the ball on the plate.
111
what is the movement if we are doing manual manipulation ?
downward and then upward
112
notices on the occlusal rim should be in which area?
posterior area (premolar/molar)
113
what is the depth for the notches?
1-2 mm
114
why do we record jaw relationship?
1- establish and maintain harmonious relationship with the oral structures
2- to distribute the forces as equal as possible
3- to prevent deflection
4- to prevent rotation
115
how can we record maxillary mandibular relationship?
- Direct apposition of casts
- Interocclusal record
- Occlusal rims
116
Direct apposition of cast:
- Missing few teeth (1-2) with existing opposing teeth
- Few teeth to be replaced on short denture base
- Can be positioned by hand
117
Interocclusal record :
- For Kennedy class III and IV
- Can't be positioned by hand
- Sufficient teeth remaining
- Fixed restoration
- Wax and bite registration
118
Occlusal rims:
- Kennedy calls I and II
- when we don't have sufficient teeth remaining or occluding
- Tooth bounded (Kennedy class III) edentulous area is large
- Opposing teeth do not meet
119
what is record base:
- recording maxillomandibular relationship
- For teeth arrangement
- Baseplate+occlusal rim
120
what is the suitable thickness for the baseplate?
2-3 mm
121
what are the uses of occlusal rims?
- Occlusal level
- Teeth arrangment
- Arch form
- Maxillary mandibular relationship
122
what are the types of facebow?
- Arbitrary
- Kinematic
123
what is the arbitrary facebow?
- Approximately located on the hinge axis 5 mm
- Uses posterior points and locate the condylar rods
- Earpiece and fascia
124
what is the kinematic facebow?
- Determine the true hinge axis
- More accurate
- For FPD and full mouth rehabilitation
125
what is the hinge axis ?
imaginary line between the mandibular condyles which the mandible may rotate in a sagittal plane
126
the third reference point is ?
we have 2 posterior points (condyle ) and 1 anterior with (nation or infraorbitale)
127
what is the difference between direct and indirect articulator?
for the indirect we will need a transfer
128
uses of simple hinge?
- not advisable
- cause occlusal interference
- used for observing intercuspal relationship
- Used for single crowns
129
uses of Average value?
fixed prosthodontics
130
what is the altering component of Average value?
incisive guidance
131
what is the altering components in Semi-adjustable?
- Bennett angle (15)
- Incisal guidance
- Condylar guidance
132
what is Bennett angle?
formed between the sagittal plane and the average path of the non working side
133
what are the types of semi adjustable ?
Arcon and non arcon
134
what is he difference between the arcon and non arcon
Arcon: Condyle attached to the mandibular arm of the articulator which is anatomically correct
Non arcon: Condyle attached to the maxillary arm housed in a track to the mandibular component which is anatomically incorrect
135
what is the altering component of fully adjustable?
- Bennett angle
- Incisal guidance
- Condylar guidance
- Intercondylar distance
136
the incisal pin should be at which marking?
zero
137
what is retruded contact position ?
the initial tooth contact upon closure when the condyles have purely rotated whilst in their most superior unrestrained position in the glenoid fossae.
138
When the mandible moves, teeth slide over each other. This partly determined by:
- Shapes of the teeth( anterior guidance)
- Anatomical constraints of the TMJ (Posterior guidance).
139
Lateral movements is guided by
- condyle- fossa relationship
- teeth relation ships
140
what is the AG?
it’s the effect of the contact between the incisal edges of the lower teeth and that of palatal surfaces of the upper teeth on mandibular movement.
141
what is Steep incisal guidance:
- when we have increased separation in the posterior teeth
- It will cause heavy load on the anterior teeth
142
how much is the condylar guidance ?
30-60
Average: 45
143
what is christens phenomenon ?
when the teeth are edge to edge and we have posterior teeth separation
144
Requirements for Anterior Guidance
- Patient comfort
- Smooth guidance, that is , there are no mandibular deflection.
- Acceptable aesthetics & phonetics.
- Minimal movement of guidance teeth
- Posterior disocclusion.
- No cementation failure of fracture of the interim restorations.
145
Manifestations of problems with guidance:
- wear
- fracture
- tooth mobility/ migration
- tmj dysfunction
146
what type of occlusion is recommended in complete denture?
Balanced occlusion
147
In natural dentition if you are edge to edge but you have posterior occlusion also what dies it mean?
occlusal interference and should be corrected
148
what are the Posterior teeth-cuspal inclination?
- Anatomic (30,33,45)
- Semi anatomic (20)
- non anatomic Flat (0)
149
Anatomic teeth?
- effective in chewing food.
- aesthetically pleasing.
- designed to be set in balanced articulation.
- If it is not in a balanced position trauma of the denture bearing area will occur.
150
Non-anatomic teeth?
- Not effective in chewing
- Not aesthetically pleasing
- Flat teeth
- Allow even contact without deflection
- Set in a simple hinge articulator
- Used in a monoplane occlusal schemes
- When we have resorbed alveolar ridge
151
advantages to anatomic teeth
- Effective in chewing
- Aesthetic
- Resist rotation
- Harmony with TMJ
- Mechanical and physiological occlusion
152
disadvantages to anatomic teeth:
- Lateral torque
- Relining and rebasing are difficult
- Require good registration
153
Advantages of non anatomic ?
-1. They don’t lock the mandible into one position.
-2. They minimize horizontal pressure due to no inclined planes.
-3. Closure can occur in more than one position---centric relation can be an area rather than a point.
-4. They can easily adapt to Class II & III jaw relationships.
-5. They accommodate to changes in vertical and horizontal relations of ridges.
-6. Relining and rebasing is easier.
-7. They improve denture stability.
154
Disadvantages of non anatomic
-1. Less efficient mastication---do not penetrate food well.
-2. Clogging of occlusal surfaces with food occurs.
-3. They are esthetically inferior to anatomic teeth
155
which type of material for teeth is mostly used ?
Acrylic
156
Acrylic
- Easy to bond chemically
- Easy to adjust
- Disadvantage: Low resistance to wear
157
Porcelain
- High wear resistance
- Difficult to adjust
- Difficult to bond (mechanically)
- Noise when eating
158
Composite
- Similar to acrylic
- When we have natural opposing teeth
159
Metal onlay
on top of the acrylic teeth restorations can be incorporated onto the acrylic teeth in cases in which the rate of wear of the acrylic teeth has been extremely rapid
160
Balanced occlusion =
- CG*IG/CI*CC*OP
161
which curve is for mediolateral or anteriorpopsterior?
mediolateral (curve of wilson)
162
what is the condylar guidance ?
it is the angle between the horizontal plane and the superior wall of the glenoid fossa
163
one factor that the dentist has no control over since it is the property of the patient
Condylar guidance
164
what should the incisal guidance
the anterior guidance should be reduced for the anatomical the overbite should be 0.5 and overate 1-2 and for the non anatomical it should be 0
165
which factors the dentist can modify ?
- Cuspal inclination
- Compensating curve
166
which cusp is occluding in the lingalized?
palate cusp
167
which one can be effectively used when a complete denture opposes a removable partial denture.
lingualized
168
what is the main indication for immediate denture?
periodontal disease
169
when remounting is needed ?
- when there is no contact in the posterior
170
if you have a small space during say "S" what does it mean and if you have a big space ?
small : whistle
big : lisp "sh"
171
size of the teeth is determined by ?
interalar distance or commissure of the mouth
172
characterization of the maxillary lateral incisors ?
soft effect (mesial flare)
173
what are the systemic conditions that are contraindicated for tooth extraction ?
- necrosis, osteoporosis, xerostomia and poor diabetes control
- Keratotic and dyskeratosis form vB and A deficiency
- Psychogenic symptoms
- Mucosal diorders
- Cerbero/cardivascular with clotting disorder.
174
what is the first and second surgical phase in conventional?
1: posterior extraction
2: Anterior extraction
175
where are the common ares that will have sore spots after wearing denture for 24 h?
- retromylohyoid
- Lateral to tuber-sixties
- Cuspid eminence
- Posterior limit areas
176
collapsed posterior bite results in ?
- Anterior flaring
- tooth loss
- Tooth fremitus/mobility
- Loss of VD
- Secondary occlusal trauma
177
Prolonged tooth loss without replacement may cause complications:
- (TMJ) disorders
- Mandibular deviation movements
- super-eruption of opposing teeth
178
what are the signs and symptoms of loss of VD:
- Inverted smile
- Toothless smile
- Frequent chipping or breaking the teeth
- Angular chelitis
- Low face height
179
What are the indications to change (increase) the OVD?
a) harmonizing dentofacial esthetics;
b) providing adequate space for the restorative material; and
c) improving incisal and occlusal relationships.
180
what are the ways for processing ?
- Conventional (compression molding)
- Injection molding
181
what are the steps for processing ?
1- Flasking
2- Boil out
3- Packing
4- Curing
5- Deflasking
6- Lab remount
7- Decasting
182
what are the changes that could happen during flasking ?
1- Dimension changes in the wax after teeth setup
2- Polymerization shrinkage
3- Expansion of the investment material
4- flask pressure
183
Advantages of CAD/CAM for fabrication?
1- Decreased porosity = decreased candida albican adherence
2- Files are saved
3- Lab steps are reduced
4- Polymerization shrinkage is prevented
184
which type of implants is the mostly used?
endosteal
185
what are the problems associated with subperiosteal (epos teal) implant ?
- invasive surgery
- impression of the bone - mucosal perforation and infection
186
what is the load bearing capacity for implants in the maxilla and mandible ?
100 kg mandible
30-50 kg maxilla
187
what made the implants successful ?
osteointegration
188
the reason behind branemark success ?
- biocompatible titanium
- Adequate and quality of the bone
- Primary stability
- avoid excessive heating
- prevent contamination
- free of load
189
what is a successful implant?
- Not mobile
- No bonne résorption
- Hugh survival rate
- No radiolucinces
- No pain
190
what is the disadvantage of acid etching ?
damage the mechanical performance
191
how osteointegration can be accelerated?
- Increasing surface area
- Increase surface chemistry
192
which type is the most stable surface treatment ? for roughness
sand blasting (silica particles )
193
what is the disadvantage of hydroxyapatite for surface chemistry ?
peel off which will cause a gap btw the implants and the bone = infection and failure
194
what is the advantage or micro thread?
reduce bone resorption or loss
195
what is the characteristics for better thread design?
- micro thread coronally (disadvantage in the mechanical stability )
- apical drilling blade
- increased screw thread lead
- double thread
196
what is the advantage of internal connection
- Force distribution
- Mechanical stability
- Mostly used
197
which type of impression is the best for IRO?
abutment level impression
198
in the maxilla and mandible how many implants do you need?
2 for the mandible and 4 for the maxilla
199
endocrown concept is a ?
monoblock concept
200
what are the indications of endocrown ?
- Extensive coronal loss
- Short clinical crowns
- Cavity depth 3 mm and 2 mm width cervical margin
- posterior tooth with extensive tissue compromising associated endodontic treatment
201
why enodcrown is useful
because here we avoid post preparation of the rc
202
which type of margin is in endocrown?
butt joint margin
203
what is the most problem with endocrown?
debonding
204
which material is the best for endocrown
lithium disilicate
205
what are the main advantages of rubber dam in endocrown ?
1- visibility of the margin
2- Dryness
3- Adjustments
206
207
type of etch in endocrown ?
internal surface for the crown - hydrofluoric acid
teeth surface - phosphoric acid
208
what are the mode of failure in endow crown and traditional crown?
endocrown :
- Loss of retention (debonding)
- Periodontitis
- Fracture
Traditional crown:
- Fracture
- Root fracture
- Irreversible pulpits
209
209
steps for initial placements and adjustments
1- Inspection
2- Framework
3- Fit
