final material to study but all the NEW material Flashcards
1
Q
Teeth better able to tolerate vertical forces:
A
down long axis
[more PDL fibers activated to resist force]
2
Q
if there is excess force with rpd, what are 2 things that could happen
A
- bone resorption
- mucosal ulcerations
3
Q
listed are the forces acting on RPD. what are the requiremets of the RPD from these forces
1. vertical(dislodgement)
2. horizontal (lateral)
3. vertical (seating)
A
- retention
- stability
- support
4
Q
involved with RPD retention (vertical dislodgement)
A
- proximal plates
- retentive clasp
- indirect retainer
5
Q
involved with stability (horizontal, lateral movement)
A
- minor connectors
- proximal plate
- denture base
- lingual plates
6
Q
involved with vertical support (seating)
A
- rests
- major connectors: max tooth-tissue supported rpd
- denture base
7
Q
rotation in vertical plane through the longitudinal/sagittal fulcrum, the fulcrum is through:
this is when the rpd:
A
crest of ridge
when rpd rocks side to side
8
Q
rotation in sagittal plane around horizontal plane fulcrum, the fulcrum is:
this is when the rpd:
A
through the rests closest to the edentulous areas
class I or II
inferior superior denture base movement of distal end
9
Q
rotation in horizontal plane through vertical plane, the fulcrum is:
this is when rpd:
A
at center of dental arch
horizontal twisting results in buccolingual movement of RPD
10
Q
this type of RPD directs detrimental distal tourquing force to abutment teeth and the retentive clasp tip is anterior to the fulcrum line
A
combo clasp: distal rest, distal guide plate, distal extension
have to use distal rest and when teeth are mesially tilted/tissue undercut
-have to use wrought wire also
class I lever and not good compared to other options
11
Q
this rpd produces less leverage on abutment than compared to using a distal rest
A
mesial rest/distal guide plate/ distal extension RPD
retentive clasp tip is distal to fulcrum line= class II lever
*circumferential clasp moves mesially during function
12
Q
when a class I lever of distal RPD extension and NO indirect retention, this occurs
A
vertical dislodgement
13
Q
for distal extension RPDs that are class I levers WITH indirect retainers, what are some alternative options can do to not have indirect retainer with retentive clasp in front of fulcrum line?
A
- no retentive clasp
- clasp in less undercut
- non-retentive clasp (clasp not in undercut)
- wrought wire clasp
14
Q
with distal extension rpd and indirect retainer is present, what type of lever is this?
is there vertical dislodgement?
A
class II lever
MINIMAL vertical dislodgement
15
Q
when blocking out spaces with wax for relief, what are two areas that DO provide relief and have to be blocked out:
A
- space between the framework and cast/soft tissue
- beneath framework extension in edentulous areas
-provide attachment of denture base
-form internal finish line
16
Q
prepared master casts are duplicated to produce an exact copy of the master cast in investment material. this is known as a
A
refractory cast
17
Q
on what cast is the framework pattern made on with wax
A
refractory cast
18
Q
an impression using agar (reversible hydrocolloid) is made of the block out on the master cast to create
A
the refractory cast
19
Q
block out and RELIEF wax is placed on this cast
A
master cast
20
Q
the master cast at the lab is duplicated twice to make these casts
A
refractory cast: what the framework IS made on
duplicate cast: will try on once framework is done
21
Q
the wax-up of the RPD framework is completed on this cast. relief wax and block outs are present on this cast as well but as stone
A
refractory cast
22
Q
what are 4 examples of possible causes for framework misfit
A
- faulty impression technique
- faulty casts
- tooth movement
- casting inaccuracy
23
Q
framework should seat with/without click
A
without
24
Q
4 objectives of the insertion appointment
A
- fit denture base to edentulous ridge
- correct occlusal discrepancies
- adjust retentive clasp is needed
- home care
25
explain selective grinding
1. adjust opposing tooth not denture tooth
2. always adjust fossas
3. alter inclination of cusps so dont lower cusp height
26
how long must RPD be removed each day
8 hours
27
once RPD removed from mouth, must do this
soak to prevent distortion of acrylic
28
for adjustment appointments after insertion appt, patient must be seen at what two time increments
1. 24 hours after insertion
2. 1 week after insertion
29
if patient has cheek biting complaint this means
insufficient horizontal overlap between max and mand teeth
30
If patient has been missing teeth for long time, could have lost:
this is why they are having difficulty in chewing
will eventually go back to normal
neuromuscular skills
31
gagging complaint is due to
max RPD overextended or poor adaptation to hard palate
[junction of movable and immovable tissue] aka vibrating line
could also mean bulky
32
lacerations or ulcerations of the soft tissue surrounding denture base is due to
overextended denture base
33
the 4 following things should be evaluated BEFORE the fabrication of new RPD
1. max and mand tori
2. exostoses
3. sharp prominent myohyoid ridges
4. epulis fissuratum
34
localized or generalized chronic inflammation of the denture bearing mucosa.
there is redness and a burning sensation with or without discomfort
can treat when nystatin, improved OH. tissue conditioners, and new well fitting rpd
denture stomatitis
35
red patch of atrophic or erythematous red and painful mucosa
acute atrophic candidias
36
antibiotic sore mouth, a common form of atrophic candidiasis should be suspected on a patient that develops symptoms of:
oral burning
bad taste
sore throat during or after therapy with broad spectrum antibiotics
37
found on the palatal vault. the causes are local irritation, poor-fitting dentures, poor OH, and leaving dentures in 24 hours a day
bumpy and red
papillary hyperplasia
38
best impression technique for patient with loose hyperplastic tissue is to register the tissue in its
passive position
39
most important reason for treatment/removal of hyperlastic tissue before construction of RPD is to:
provide a firm, stable base for the denture
40
kelly's combination syndrome is refered to as a specific pattern of:
bone resorption in the anterior portion of edentulous maxilla
41
what results from the anterior bone resorption in kelly's combination syndrome
mandibular distal extensions resorption occurs causing downward growth of the maxillary tuberosities and tipping of the occlusal plane
42
treatments for kelly's combo syndrome
1. mand posterior implants
2. reline/rebase/tissue conditioner
43
Soft materials that are applied to the intalgio surface of complete or RPD to allow a more equitable distribution of forces throughout the dental arch
"SHORT insert/term'; lasts 1 week
tissue conditioner
44
To be effective in treating abused oral tissues, tissue conditioners must be changed every
3-5 days
45
when using tissue conditioner, what must the patient do if there are posterior artifical teeth present and you have applied the conditioner
patient MUST close the teeth together while conditioner is still capable of flowing in order to align the teeth properly with opposing occlusion
46
wrought wire clasp must have elongation percentage of
more than 6%
47
the mechanical properties of (wrought wire/cast structure) such as tensile strength, hardness and strength, are superior to the other
wrought wire is superior to cast metal (by 25%)
48
the physical characterisitics of wrought wire can be reduced drastically by
too much heat
this happens by change in microstructure of WW with process known as recrystallization or grain growth and is the most undesirable occurrence on WW arms
49
this metal is used most for fabrication of cast framework
Chromium Cobalt
50
Chromium cobalt is most used for cast frameworks because of their
low density, high modulus of elasticity (stiffness), low material cost, resistance to tarnish
51
compositions of chromium alloys:
chromium:
cobalt:
nickel:
chromium: resist tarnishing
cobalt: strength ,rigidness, hardness
nickel: increases ductility
52
HIGH modulus of elasticity and therefore LOWER FLEXIBILITY
CHROMIUM COBALT ALLOYS
elastic (ability to return to original shape)
flexibility (ability to bend without breaking)
53
what are 4 possibly causes of failure of Cr-Co:
1. cold-working (reduces % of elongation that causes decrease in hardness)
2. shrinkage porosity (shrink 2.3%)
3. low % elongation (directly related to greater brittleness)
4. excessive carbon in the alloy (reacts with other stuff to form carbides)
54
Cr-Co 4 advantages
1. high elastic
2. low flexibility
3. low cost
4. low density (weight)
55
most basic of rpd maintenance techniques and involves adding new denture base material to existing resin to make up for loss of tissue contact caused by resorption of alveolar ridge
relining
56
alginate mixture ratio that is enough not to displace soft tissues and set quickly so can evaluate space under denture
1 scoop of alginate and 2 measures of hot water
57
if at least ____mm of alginate is present under the denture base or if the indirect retainer lifts ____mm or more, the patient can be considered for a reline or rebase
if existing denture is short of ideal coverage, a rebase should be used instead of reline
2mm
2mm
58
If there is a bulk of alginate impression material at the buccal shelf area and at the crest of the ridge what is indicated
reline
59
2 reasons why denture resin must be removed from intaglio surface before impression
1. enough space so impression material will not apply under pressure to soft tissues
2. remove contaminants and ensure good bond
60
what tissue being impressed uses free-flowing, zinc-oxide eugenol impression material
mobile tissue on crest of ridge
61
what tissue being impressed uses polysulfide rubber bases, polyethers, PVS, and mouth temp waxes
dense, firm denture base tissue
62
Most critical step in reline process for impression:
Maintenance of tooth-framework relationship during the set of the impression material
patient CANT bring teeth into contact during impression making procedure.
dentist must HOLD framework against abutment teeth
63
explain intraoral reline
1. inferior to lab relines
2. porous and will lack color stability
3. quick improved relationship between denture base and soft tissues
64
what are the 3 indications of rebasing
1. does extend to cover all denture bearing tissues
2. fractured
3. discolored
65
lab technique is which bulk of denture base removed and replaced using new resin
rare, will typically just make a new one. do if new
rebasing
66
When both the denture base and the denture teeth are involved, RPD must be
remade
67
Prior to RPD treatment, students complete:
1. Comp exam and oral diagnosis
2. All necessary consults (medical and dental)
3. Develop comp treatment plan
4. Survey articulated dx cast
5. Draw rpd design cast and have faculty approval
6. NEED MOUNTED CASTS BEFORE TALKING TO FACULTY
68
patients first appointment this is done:
1. medical and dental hx
2. pano and PAs of potential abutment teeth
3. complete perio and restorative charting
4. Dx casts!
5. pulpal evaluations of abutment teeth
69
patients second appointment this should be done
1. review x-rays
2. take any additional x-rays
3. identify any additional teeth needing ext
4. pulpal test potential abutment teeth if not done already
5. dx necessary restorations [some done at first appt; surveyed crowns]
6. soft tissue/residual ridge support
7. vertical space
consider ortho before even touching tooth!
70
when typing treatment info into axium, begin with this appt first
begin with disease control procedures first
71
When do you decide to do surveyed crown
1. restore badly broken down crown
2. establish proper occlusion (like supra-erupted tooth)
3. create proper rest/good undercut
72
it is essential that re-contouring procedures be completed _______ crown (fixed restoration) procedures are begun. this includes the preparation of guiding planes and rest seats
before
73
The occlusal or cingulum rests are constructed in:________
Areas that engage retentive clasps can be in: _______
Guide planes in: _____
metal
metal or porcelain
metal
74
how should the guiding planes be compared to the guiding planes on the remaining teeth
parallel
this improves parallelism between guiding planes and gets better result
75
how are the guiding planes created on a surveyor crown
using wax knife in vertical arm of dental surveyor
76
dental ceramics are strong in ________, but weak in ________
strong compression
weak tension
77
explain optimal functional occlusion aka mutually protected occlusion
1. even occlusal contacts of posterior teeth in MIP with mandible in CR position (MIP and CR same)
2. anterior teeth have lighter occlusal contact compared to posterior teeth in MIP
3. posterior teeth are axially loaded in MIP
4. excursive movements, there is canine guidance and anterior guidance
78
Posterior teeth withstand majority of the load in MIP, protecting the anterior teeth from
high loads
79
Anterior teeth disclude the posterior teeth in excursive movements, thereby protecting the posterior teeth from
off-axis loading
80
3 occlusal schemes during excursive movements
1. canine guidance- anterior guidance
2. group function (unilateral balance)
3. balanced occlusion (bilateral balance) [DONT WANT IN NATURAL DENTITION] [contacts both sides with movements]
81
optimal functional occlusion during excursive movements has canine-anterior guidance meaning the canines on the _____side guide the movement when the mandible moves laterally causing all other teeth to disclude
working side
82
in anterior guidance, Contacts between the posterior teeth during excursive movements are considered ________ than can create effect on teeth and periodontium
interferences
83
why is canine guidance/anterior guidance the optimal occlusal scheme?
1. mandible = class III lever
the more anterior (away from the fulcrum), the resistance (load) occurs, the lesser the impact (magnitude)
2. the canines have the longest root and best bone support
84
anterior guidance is a ______rather than a fixed factor
variable
85
anterior guidance is controlled by
position and contours of anterior teeth
86
anterior guidance is altered by
caries, restoratins, exts, ortho, habit, tooth wear
87
the angle formed by the intersection of the horizontal plane and the disclusive pathway of the anterior teeth
anterior guidance angle
88
what two things is the anterior guidance angle influenced by
HO and VO
horizontal overlap and vertical overlap
89
increase in VO=
increase in HO=
increase VO= increase anterior guidance angle
increase HO= decrease in anterior guidance angle
90
in group function, when the mandible moves laterally, the outer inclines of the mand buccal cusps on the working side, slide along
the inner inclines of the buccal cusps of max posterior teeth, guiding the movement
91
this occlusion is not acceptable for dentate patients, promotes tooth wear on natural teeth, and non-working side contacts are extremely destructive and must be avoided.
this CAN be acceptable form of occlusion for removable prostheses
balanced occlusion
contacts working and non working sides at same time
92
Lack of posterior occlusion,
Significant wear of maxillary and mandibular anterior teeth,
Mand anterior teeth are supererupted, posterior teeth are supraerupted
malocclusion
93
