pros Flashcards

1
Q

CoCr indications

A

greater strength
more hygienic design possible

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2
Q

acrylic indications

A

temporary denture
poor OH or likely to have denture additions
cheaper
inadequate support from remaining teeth alone (need mucosa support too)

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3
Q

kennedy classification

A

anatomical classification that describes the number and distribution of edentulous areas present

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4
Q

kennedy class I

A

bilateral free end saddle

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5
Q

kennedy class II

A

unilateral free end saddle

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6
Q

keneedy class III

A

unilateral bounded saddle

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7
Q

kennedy class IV

A

anterior bounded saddle
crossing the midline

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8
Q

craddock classification

A

simple classifciation based on support

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9
Q

craddock class I

A

tooth bearing
preferred - most comfotable, natural feeling (load transmitted via PDL)

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10
Q

craddock class II

A

mucosa bearing supporting

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11
Q

craddock class III

A

mixed - tooth and mucosa borne

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12
Q

support
definition

A

resistance to occlusal directed forces
prevents/resists movement and distributes load

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13
Q

support can be provided by

A

utilising hard tissues (teeth, bony undercuts) and large surface coverage (palate)

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14
Q

functions of rests

A
  • Oppose movement of denture base towards tissue (support),
  • help distribute/direct occlusal loads (down long axis of abutment tooth),
  • provide anterior bracing,
  • involved in reciprocation and indirect retention,
  • determine axis of rotation for free-end saddle RPDs
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15
Q

how should rests be placed

A

Kennedy I/II - not immediately adjacent to saddles (free end)
Kennedy III/IV - immediately adjacent to saddles (bounded)

Craddock I - on tooth surface nearest base
Craddock III - on tooth surface not closest to base

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16
Q

rests

A

Components that provide mechanical support. Extension of the denture onto a tooth.

Described by the part of the tooth that they contact.

Rests in CoCr are rigid and strong and connect to base via connectors.
PMMA rests are flexible and have poor strength and are mechanically incorporated within the base and loads can cause stress

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17
Q

features f mucosal supported denture

A

As large an area as possible, base must be 3mm from gingival margin to adduct for soft tissue compressibility

every partial denture - Entirely mucosa-borne. Restores arch with contact points, wire stops prevent distal drift of most posterior teeth. Gingival margins not covered

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18
Q

retention

A

resistance to vertical displacement.

Mechanical, muscular, physical

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19
Q

direct retention

A

esistance to vertical displacement of denture. Clasps, guide planes, soft tissue undercuts, precision attachments

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20
Q

direct retention

A

esistance to vertical displacement of denture. Clasps, guide planes, soft tissue undercuts, precision attachments

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21
Q

indirect retention

A

resistance to rotation displacement of denture. Provided by placing components to resist rocking

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22
Q

ideal pattern of retention

A

Triangular, with one point on opposite side of the arch

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23
Q

retainers

A

Components that resist displacement of the denture

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24
Q

indirect retainers

A

Resist rotation about the clasp axis by acting on the opposite side to the displacing force.

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25
Q

fulcrum axis

A

Axis around which a tooth and Craddock III denture tends to rock when the saddles are loaded

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26
Q

mechanical retention
ways to provide

A

Clasps and guide planes

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27
Q

guide planes and how do they work

A

Retention through friction.
Supplementary direct retention.
Two or more parallel surfaces on abutment teeth used to limit the PoI and improve retention and stability

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28
Q

what do altered PoI provide

A

retention

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29
Q

what do clasps do
how to do they work

A

Provide retention by engaging the undercut of a tooth

If the clasp arm is seated below the undercut

30
Q

clasp efficacy depends on

3

A

Material,
cross-sectional thickness and shape,
length

31
Q

material and length for 0.25mm undercut

A

cast CoCr
at least 15mm

32
Q

0.5mm undercut material

A

wrought gold

33
Q

0.75mm undercut

A

wrought strainless steel

34
Q

how is muscular rentention achieved

A

action of surrounding musculature on the shape of the polished surface. Involves patient’s muscular control and denture extension into sulcus

35
Q

how is muscular rentention achieved

A

action of surrounding musculature on the shape of the polished surface. Involves patient’s muscular control and denture extension into sulcus

36
Q

how is physical retention achieved

A

Existing forces of **adhesion, cohesion, surface tension, atmospheric pressure. **

Includes closeness of adaptation, extent of base and peripheral seal

37
Q

how is indirect retention achieved

A

Extension of the base to provide a fulcrum of a class II lever, preventing rotation. Stability for free-end/very long bounded saddle

38
Q

reciprocation
how to achieve

A

Movement/force of the opposing element to prevent pressure from the retentive clasp arm acting on the tooth (resistance to lateral movement).

Provided via reciprocating (non-retentive) clasp arm (or reciprocal connector) above maximum bulbosity of the tooth remaining in contact with the tooth, prevent horizontal tooth movement caused by action of clasp flexing.

39
Q

RPI system

A

Stress reliving clasp system. Used in Craddock III and commonly for Kennedy I/II.
Used to reduce load on such teeth

Mesial rest, proximal guide plate, gingivally-approaching I-bar clasp
* As the saddle sinks into the denture bearing mucosa there is a rotation of the denture around the mesial rest
* Both the distal guide plate and the I bar rotate downwards and mesially and disengage from the tooth
* Potentially damaging torque avoided

Retention, indirect retention (via proximal plate and minor connector) and reciprocation (if gap between plate and connector is less than width of tooth)

39
Q

RPI system

A

Stress reliving clasp system. Used in Craddock III and commonly for Kennedy I/II.
Used to reduce load on such teeth

Mesial rest, proximal guide plate, gingivally-approaching I-bar clasp
* As the saddle sinks into the denture bearing mucosa there is a rotation of the denture around the mesial rest
* Both the distal guide plate and the I bar rotate downwards and mesially and disengage from the tooth
* Potentially damaging torque avoided

Retention, indirect retention (via proximal plate and minor connector) and reciprocation (if gap between plate and connector is less than width of tooth)

40
Q

major connectors
role
types

A

connect components on one side of the arch to the other

plate
bar
ring

41
Q

space needed for lingual bar

A

8mm (3mm from gingival margin, 4 mm height of bar, 1mm clearance to Fom)

42
Q

3 key anatomical features for complete dentures

A

Hamular notch
* area between distal surface of tuberosity and hauler process of medial pterygoid plate; ideal site for distal border,
* helps with post seal

Retromolar pad
* triangular pad of soft tissue at the posterior end of the lower edentulous ridge.
* Support

Retro-mylohyoid space
* space at distal end of lingual sulcus, posterior to mylohyoid.
* Aids in retention and stability

43
Q

impression definition

A

reverse/negative form of the tissue

44
Q

Cawood and Howell ridge classification

A

I. I - dentate;
II - post-extraction;
III - broad alveolar process;
IV - knife-edge;
V -flat ridge (no alveolar process);
VI - submerged ridge (loss of basal bone)

45
Q

what is support in C/C

A

Resistance to vertical movement of denture (occlusal directed forces).

46
Q

ways support is provided in upper C/C

2

A

hard palate, residual ridge

47
Q

ways support provided in lower C/C

3

A

residual ridge, buccal shelf, retromolar pad

48
Q

retention

A

reistance to displacmeent in a vertical direction

49
Q

3 ways to get retention

A

Peripheral seal, contact area between denture and tissues,
denture extension,
close fit,
viscosity/volume of saliva** (adhesion cohesion)**

50
Q

stability

A

Resistance to horizontal movement

51
Q

ways to get stability

A

Stable/flat occlusal plane,
denture teeth in neutral zone,
correct denture extension.

52
Q

neutral zone

A

Area where muscular displacing forces are in balance. Ideal tooth position where displacing forces of cheeks and lips are balanced with the opposing displacing forces of the tongue

53
Q

6 ways to optimise retention and stablity of denture

A

Maximum extension of denture base,
close adaptation to mucosa,
teeth in neutral zone,
correct shape of polished surfaces,
good border seal,
balanced occlusion

54
Q

alginate

5 properties

A

mucostatic,
cheap,
easy to use,
elastic,
poor tear resistance

55
Q

impression compound

3 properties

A

non-elastic,
mucocompressive,
difficult to use

56
Q

polyether (impregum)

3 properties

A

dimensionally stable
very accurate,
hydrophilic

57
Q

occlusal stops

A

Allow accurate correction of posterior borders of tray by pre-forming impression material, improving peripheral seal

58
Q

fucntion of border moulding

A

Full the functional sulcus (depth of sulcus during normal movement)

59
Q

3 objectives of jaw registration

A

Determine occlusal plane and jaw relationship,
define shape of maxillary rim and position of lower teeth
select shade and mould of teeth

60
Q

stages in jaw registration

A

measure RVD and OVD with willis bite gauge
adjust upper record block to anterior and posteiror occlusal plane and check buccal corridors
mark lip line, midline and canine line
establish face height but adjusting lower block to upper
identify lower tooth position
take bite registration
select appropriate tooth

61
Q

assess during jaw reg

A

SOARE - Extension, retention, stability, occlusion, appearance.
LIMBO - lip line, incisive level, midline, buccal corridor, occlusion

Upper centrals 10mm anterior to incisive papilla, occlusal plane parallel to ala-tragus line

62
Q

checks for delivery

A

Function, aesthetics, 3 denture surfaces, satisfactory occlusal contacts, extension, retention, stability, incisal plane orientation, occlusal plane orientation, OVD, porosity, undercut areas, sharp areas, comfort, looseness, appearance, speech, extension, retention, stability, occlusion, occlusal planes, OVD, FWS,

63
Q

4 components of denture stomatitis (chronic pseudomembranous candidiasis)

A

Candidal infection, poor denture hygiene, night-time wear, high sugar intake, systemic factors (iron deficiency, steroid use, xerostomia).

Mx - denture hygiene, miconazole gel to fitting surface, systemic fluconazole if indicated

nystatin if on statins or warfarin

64
Q

4 components of denture stomatitis (chronic pseudomembranous candidiasis)

A

Candidal infection, poor denture hygiene, night-time wear, high sugar intake, systemic factors (iron deficiency, steroid use, xerostomia).

Mx - denture hygiene, miconazole gel to fitting surface, systemic fluconazole if indicated

nystatin if on statins or warfarin

65
Q

post dam helps in

A

Retention, stability

66
Q

reasons for looseness

8

A

Tori, flabby ridge, high renal attachment, recent extractions, incorrect peripheral extension, teeth not in neutral zone, unbalanced articulation, hyposalivation

67
Q

reasons for pain

12

A

Over-extension, blebs, residual monomer, poor fit, excessive post dam, retained roots, bruxism, premature occlusal contact, non-balanced occlusion, locked/wedged occlusion, rough fitting surface, errors in occlusion

68
Q

eating problems

A

FWS, looseness, pain, chewing at side

69
Q

speech problems

A

Incisors to palatal, incorrect OJ/OB, palatal PMMA too thick, lack of retention, reduced OVD

70
Q

overdenture
what
adv
disadv

ideal abutments

A

Denture that derives support from one or more abutments or implants - seated over the top of these

Preserve alveolar bone around retainer tooth, improved support, retention and stability, preservation of proprioception via PDL, psychological benefit of maintaining natural teeth

RCT likely required, increased fracture risk, more maintenance required by patient and dentist, roots prone to caries, base may be required to be thinned to avoid excessive bulk in the region of the retained tooth

Canines > molars > premolars > incisors
Ideally bilateral and symmetrical with minimum of one tooth space between them; healthy attached gingiva, good perio support, no mobility