Cr2 Exam #2 - Rpd

Front 1

Prosthesis

Back 1

An artificial replacement of an absent part of the human body.

Front 2

Prosthetics

Back 2

The art and science of supplying missing parts of the human body

Front 3

Prosthodontics

Back 3

That branch of dental art and science pertaining to the restoration and maintenance of oral function by replacement of missing teeth and structures with artificial devices

Front 4

Complete Dentures

Back 4

Dental prosthesis which replaces the entire dentition and associated structures of the maxillae or mandible

Front 5

Removable Partial Denture

Back 5

A prosthesis which artificially supplies teeth and associated structures in a partially edentulous jaw, and which can be removed from the mouth and replaced at will.

Front 6

Components of RPD

Back 6

- Major connector
- Minor connector
- Rests
- Direct retainers
- Reciprocal or bracing components
- Indirect retainers
- Bases supporting replacement teeth

Front 7

Abutment

Back 7

A tooth used for the support or anchorage of a fixed or removable partial denture

Front 8

Two main types of RPD

Back 8

1- Tooth supported ( tooth-borne )
2- tooth and tissue supported ( tooth and
tissue Borne )

Front 9

Tooth supported RPD

Back 9

A removable partial denture which drives its support from the abutment teeth at each end of the edentulous area

Front 10

Tooth and tissue supported RPD

Back 10

A removable partial denture that drives its support from both the teeth and the tissues of the residual alveolar ridge

Front 11

Denture base

Back 11

That part of the RPD which supports the artificial teeth and is in contact with the edentulous ridge

Front 12

Distal extension Base

Back 12

Denture base extending posteriorly in a tooth and tissue supported RPD

** in some dental schools, they call it “free end” (not accepted terminology)

Front 13

Dental surveyor

Back 13

An instrument used to determine the relative parallelism of two or more surfaces of the teeth or other parts of the cast of a dental arch.

Front 14

height of contour

Back 14

AKA "survey line" or "area of greatest convexity"

Front 15

Requirements of an acceptable method of classification of partially edentulous arches

Back 15

1- Immediate visualization of the type of edentulous arch.
2- Immediate differentiation between the tooth-supported and the tooth-and-tissue supported RPDs.
3-Should serve as a guide to the type of design to be used.
4- Should be universally accepted.

Front 16

Kennedy Classification of Partial Edentulous Classes

Back 16

Class I : Bilateral edentulous areas located posterior to the remaining natural teeth.

Class II: A unilateral edentulous area located posterior to the remaining natural teeth

Class III : A unilateral edentulous area with natural teeth remaining both anterior and posterior to it

Class IV: A single but bilateral (crossing the midline) edentulous area located anterior to the remaining natural teeth

Front 17

Kennedy Class I

Back 17

Class I : Bilateral edentulous areas located posterior to the remaining natural teeth.

Front 18

Back 18

Class I : Bilateral edentulous areas located posterior to the remaining natural teeth.

Front 19

Kennedy Class II

Back 19

Class II: A unilateral edentulous area located posterior to the remaining natural teeth

**can cross the midline

Front 20

Back 20

Class II: A unilateral edentulous area located posterior to the remaining natural teeth

** can cross the midline

Front 21

Kennedy Class III

Back 21

Class III : A unilateral edentulous area with natural teeth remaining both anterior and posterior to it

**does NOT cross the midline

Front 22

Back 22

Class III : A unilateral edentulous area with natural teeth remaining both anterior and posterior to it

**does NOT cross the midline

Front 23

Kennedy Class IV`

Back 23

Class IV: A single but bilateral (crossing the midline) edentulous area located anterior to the remaining natural teeth

Front 24

Back 24

Class IV: A single but bilateral (crossing the midline) edentulous area located anterior to the remaining natural teeth

Front 25

Applegate rules for Kennedy classification

Back 25

Rule 1: Classification should follow rather than precede any extraction of teeth that might alter the original classification
Rule 2: If the third molar is missing and not to be replaced, it is not considered in the classification.
Rule 3: If the third molar is present and is to be used as an abutment, it is considered in the classification.
Rule 4: If the second molar is missing and is not to be replaced, it is not considered in the classification.
Rule 5: The most posterior edentulous area (or areas) always determine the classification
Rule 6: Edentulous areas other than those determining the classification are referred to as MODIFICATIONS and are designated by their numbers
Rule 7: The extend of the modification is not considered, only the number of additional edentulous areas.
Rule 8: There can be no modification in class IV.

Front 26

Most Important Applegate Rules

Back 26

Rule 5: The most posterior edentulous area (or areas) always determine the classification

Rule 6: Edentulous areas other than those determining the classification are referred to as MODIFICATIONS and are designated by their numbers

Front 27

Rule 1: Classification should ________ rather than _______ any extraction of teeth that might alter the original classification

Back 27

Rule 1: Classification should follow rather than precede any extraction of teeth that might alter the original classification

Front 28

Rule 2: If the third molar is missing and not to be replaced, it (IS / IS NOT) considered in the classification.

Back 28

Rule 2: If the third molar is missing and not to be replaced, it is NOT considered in the classification.

Front 29

Back 29

Class II, Modification 1

Front 30

Back 30

Class III, Modification 1

Front 31

Back 31

We usually don’t replace third molars, unless there is an opposing tooth that we need to stabilize, so classify this without it…Class III, Modification 1

Front 32

Back 32

Class III, Modification II

Front 33

Back 33

Class III, Modification I

**you can NOT modify class IV

Front 34

Back 34

Class III

“Single edentulous area that does not pass the midline’

If you extract #9, it becomes a Class IV

Front 35

Dental surveyor

Back 35

An instrument used to determine the relative parallelism of two or more axial surfaces of the teeth and to locate and delineate the contours and relative positions of the abutment teeth

Front 36

Carbon marker

Back 36

Carbon marker: used to mark the height of contour of tooth
Undercut gauges: determines amount of undercut on teeth

Front 37

Undercut gauges

Back 37

Carbon marker: used to mark the height of contour of tooth
Undercut gauges: determines amount of undercut on teeth

Front 38

Surveying

Back 38

The procedure of locating and delineating the contour and position of the abutment teeth and associated structures before designing a removable partial denture.

Front 39

Use of the Surveyor

Back 39

1-Surveying the diagnostic cast.****
2-Contouring wax patterns.
3-Surveying ceramic crowns.
4-Placement of intra-coronal retainers.
5-Machining cast restorations.

Front 40

Purpose of surveying

Back 40

1-Determine the most acceptable PATH OF INSERTION.
2-Identify proximal tooth surfaces that can act as GUIDE PLANES.
3-Locate and measure areas of the teeth that may be used for RETENTION.
4-Determine soft or bony tissue undercuts that would act as INTERFERENCE.
5-Determine the most suitable path of insertion to satisfy ESTHETICS.
6-Aid in determining restorative procedures and TOOTH PREPARATION
7-Delineate HEIGHT OF COUNTOUR and LOCATE UNDERCUTS to be blocked out before duplication of master cast

Front 41

most important purposes of surveying

Back 41

1-Determine the most acceptable PATH OF INSERTION.
2-Identify proximal tooth surfaces that can act as GUIDE PLANES.
3-Locate and measure areas of the teeth that may be used for RETENTION.
4-Determine soft or bony tissue undercuts that would act as INTERFERENCE.

Front 42

Path of insertion (Placement)

Back 42

The direction in which a restoration moves from the point of initial contact of its rigid parts with the supporting teeth to its terminal resting position, with rests seated and the denture base in contact with the tissues.

Front 43

Guide planes (Guiding planes)

Back 43

Axial tooth surfaces made parallel to the path of insertion to direct the prosthesis during placement and removal.

Front 44

Retention

Back 44

The quality inherent in the removable partial denture that resists the vertical forces of dislodgement

Front 45

Height of contour

Back 45

A line encircling a tooth, designating its greatest circumference at a selected position determined by a dental surveyor

Front 46

Undercut (in reference to an abutment tooth)

Back 46

That portion of the tooth that lies between the height of contour and the gingivae

Front 47

Undercut ( in reference to other oral structures )

Back 47

The contour or cross section of a residual ridge or dental arch that would prevent the placement of a denture

Front 48

Torus mandibularis

Back 48

These are bony exostoses, which can serve as undercuts (apically)

Mostly found on the lingual premolar area and sometimes require surgical removal

Front 49

Factors determining the path of insertion

Back 49

1-Guide planes.
2-Retentive areas.
3-Interferences.
4-Esthetics.

Front 50

The end result of selecting a suitable antero-posterior tilt should be to

Back 50

provide the greatest area of parallel proximal surfaces that may act as guide planes

Front 51

The end result of selecting a suitable lateral tilt should be to

Back 51

provide reasonable uniformity of retention (angle of cervical convergence)

Front 52

When surveying... what is the order of the tilt?

Back 52

1) anteroposteral
2) lateral

Front 53

Reciprocal clasp arm

Back 53

Reciprocal clasp arm: rigid, straight & completely above survey line

Retentive clasp arm: flexible, tapered & terminal 1/3rd under survey line

Front 54

Retentive clasp arm

Back 54

Reciprocal clasp arm: rigid, straight & completely above survey line

Retentive clasp arm: flexible, tapered & terminal 1/3rd under survey line

Front 55

Tripoding

Back 55

Recording the relation of the cast to the vertical arm of the surveyor by placing three widely divergent dots on the tissue side of the cast on a fixed plane.

mark two posterior parts and one anterior part, which would create a triangle – 3 points will create a figure that only 1 plane can pass through

Front 56

Impression Materials

Back 56

Mucostatic (e.g. Zinc Oxide eugenol paste)
- More Fluid (Very low viscosity)
- Minimal displacement of tissues
- Will capture anatomical form of the ridge

Mucodisplacive (e.g. polyvinylsiloxane, polysulphide)
- More Viscous
- More displacement of tissues

Front 57

Mucostatic Impression Materials

Back 57

Mucostatic (e.g. Zinc Oxide eugenol paste)
- More Fluid (Very low viscosity)
- Minimal displacement of tissues
- Will capture anatomical form of the ridge

Mucodisplacive (e.g. polyvinylsiloxane, polysulphide)
- More Viscous
- More displacement of tissues

Front 58

Mucodisplasive Impression Materials

Back 58

Mucostatic (e.g. Zinc Oxide eugenol paste)
- More Fluid (Very low viscosity)
- Minimal displacement of tissues
- Will capture anatomical form of the ridge

Mucodisplacive (e.g. polyvinylsiloxane, polysulphide)
- More Viscous
- More displacement of tissues

Front 59

Advantages of Hydrocolloid Impression Materials

Back 59

- Hydrophilic (Can be used in the presence of moisture)
- Pour well with stone
- Pleasant taste and odor
- Nontoxic
- Nonstaining
- Inexpensive

Front 60

Disadvantages of Hydrocolloid Impression Materials

Back 60

- Must be poured immediately (dimensionally unstable) - Have low tear strength
- Less surface detail

Front 61

How to Pour Stone Casts

Back 61

- Technique to pour alginate is always: DOUBLE POUR TECHNIQUE
- Cover all the border with the stone and let it set
- After it sets, soak it in the water
**Soaking is critical because if you don’t soak it, the stone will not stick to the previously poured stone
- Make the base

Front 62

Custom Tray

Back 62

- 2 – 3mm thick Stepped or small handle
- Border 2mm short of depth of sulcus
- Cover the hamular notches and retromolar pads with distal extension dentures
- VLC Resin – Triad

- Idea is similar to the CD
- Only difference is that there is intact teeth remaining, so we have to provide more space. - Otherwise, the tray we make will get stuck on the case and it will break the cast.

Front 63

Custom Tray Fabrication

Back 63

- 1st layer of baseplate wax over teeth
- 2nd layer of baseplate wax over teeth and edentulous areas
- Occlusal stops to maintain space for impression material

Front 64

Where do you provide the occlusal stops in custom tray fabrication?

Back 64

Do not want stops in the area that are important (i.e. abutment teeth for RPD, rest seats, clasps…etc)

Front 65

Things to consider for Support for the distal extension denture base

Back 65

- Contour and quality of the residual ridge Extent of residual ridge coverage by the denture
base
- Type and accuracy of the impression registration - Accuracy of the fit of the denture base
- Design of the partial denture framework
- Total occlusal load applied

Front 66

Where do you bordermold?

Back 66

- Areas that will be important in terms of providing proper extensions
- Edentulous areas

Front 67

What areas are border molded ?

Back 67

Edentulous areas are border molded !!

Lingual area of the mandible: ALWAYS border-molded no matter what. Reason is because this is the area where you really need to know the size/depth of the area
- Either lingual bar (preferred connector) or lingual plate

Front 68

Types of Impression Registration

Back 68

The anatomic form:
- The surface contour of the ridge when it is not supporting an occlusal load.
---> types for when you make teeth-supported RPD

The functional form
- The residual ridge is the surface contour of the ridge when it is supporting a functional load
---> distal extension example

Front 69

anatomic form of impression registration

Back 69

The anatomic form:
- The surface contour of the ridge when it is not supporting an occlusal load.
---> types for when you make teeth-supported RPD

The functional form
- The residual ridge is the surface contour of the ridge when it is supporting a functional load
---> distal extension example

Front 70

functional form of impression registration

Back 70

The anatomic form:
- The surface contour of the ridge when it is not supporting an occlusal load.
---> types for when you make teeth-supported RPD

The functional form
- The residual ridge is the surface contour of the ridge when it is supporting a functional load
---> distal extension example

Front 71

Border Molding

Back 71

- Modelling compound sticks
- Added to tray in sections
- Must be adequately softened/tempered - Preshaped to proper contour with fingers
- Must be tempered in a water bath
- Chilled after removal from mouth
- Rounded contours

Front 72

Maxillary Border Molding***

Back 72

Anterior
- Lip - elevated & extended out, downward & inward

Buccal Frenum
- Cheek – elevated, pulled downward & inward, moved backward and forward

Posterior
- Cheek – outward, downward and inward
- Patient opens wide and moves mandible form side to side (Achieves the movement of the coronoid notch you get the proper fit and the denture does not get dislodged in the future)

Front 73

Mandibular Border Molding***

Back 73

Anterior Labial
- Lip – lifted outward, upward & inward
- these are the only movements that will minimize the sulcus extension

Buccal Frenum
- Cheek – lifted outward, upward & inward moved backward and forward

Posterior Buccal
- Cheek – outward, upward and inward
- Patient exerts a closing force while applying downward pressure (masseter muscle)
- To capture the masseteric notch, distal to the buccal shelf, you must hold the tray with your fingers and ask patient to exert a closing force

Anterior Lingual Region
- Tongue protruded - determines length of lingual flange
- Tongue pushed against front part of palate – determines thickness

Mid Lingual Region
- Tongue touches cheek on both sides
Posterior Lingual Region
- Tongue protruded – activates the superior constrictor muscle

Retromolar Pad
- Patient opens wide – determines length of posteromedial border

Front 74

Things need to do before you do tray preparation

Back 74

- Excess modeling compound removed
- Soft tissue undercuts relieved
- Adhesive applied to tray

Front 75

Impression Materials

Back 75

Elastic: flexible after they set

Thermoplastic: softened in the warm temperature and hardened by cooling them down

Rigid: set hard (metallic oxide paste are the rigid ones, but this may only be good for CD. They may not be applicable for RPD)

Front 76

Elastic Impression Materials

Back 76

Can be withdrawn from tooth and tissue undercuts without permanent deformation
- Reversible hydrocolloids
- Irreversible hydrocolloids
- Mercaptan rubber-base
- Polyether
- Silicone/ PVS: what most people use today because of its superior characteristic; high coefficient for elastic recovery. Low permanent deformation

Front 77

Thermoplastic Impression Materials

Back 77

Thermoplastic impression materials become plastic at higher temperatures
- Modelling compound
- Iowa wax and Korecta waxes
---> have the ability to flow /equalization of pressure and prevent overdisplacement

*** - Technique sensitive and require a lot of training for use

Front 78

Rigid Impression Materials

Back 78

- Plaster of Paris
- Metallic Oxide Paste

Front 79

Reasons for remaking impressions

Back 79

- Incorrect positioning of the tray
- Large voids or discrepancies
- Incorrect consistency of impression material - Movement of the tray before final set
- Incorrect border molding procedures
- Using too much or too little impression material

Front 80

Boxing Impressions

Back 80

- Preserves functional width of sulcus
- Preserves functional depth of sulcus
- Boxing wax strip attached 2-3mm
below border
- Vertical wall extends 10-15mm above impression
- Seal wax with hot spatula

Front 81

McLean/Hindels Technique

Back 81

Before access to materials such as PVS. McLean/Hindels technique: the custom tray is made to cover only the edentulous areas, and there is a space that has been created under the parts that connects the sites.

Impression of the edentulous areas is first obtained, you can use fingers to apply a certain amount of pressure, and as the next step you use the tray. That tray has two holes which are used by your fingers to support the distal extension bases while a second impression is taken to pick up the details of the soft tissues.

Front 82

Corrected Cast Procedure***

Back 82

- Framework is made on a cast that doesn't have proper extensions. You pick up the extensions in a compressed state.
- block undercuts w/ wax.. and then create a resin base that is properly extended
- The area is border molded using traditional techniques. The impression of the edentulous area is made. The impression will not fit on the cast, so you have to alter the cast to make sure that it fits. You cut off, or remove, the edentulous part completely. Only the teeth that aren't involved will create a resin base that has been extended.
- it is now retrofitted back to the framework and the teeth allow the precise position . You then turn it over and box & pour

Front 83

Rests

Back 83

A rigid (stabilizing) extension of a fixed or removable partial denture which contacts a remaining tooth or teeth to dissipate vertical or horizontal forces

Front 84

rest vs. rest seat

Back 84

Rests are the extension of the framework – metal part that comes in contact with the tooth and rests on it.

Rest seats are the areas of teeth or restoration that will accept the rest.

Front 85

Purpose of a rest?

Back 85

- Direct occlusal forces along long axis of the abutment tooth
-minimize or prevent the movement of the denture framework towards the soft tissue – minimizing chances of trauma to free gingival margin (right next to the teeth).
- maintain the retentive clasp in that specific position

Front 86

Occlusal rests

Back 86

seated on the occlusal surfaces of posterior teeth

Front 87

Lingual or cingulum rests

Back 87

seated on the lingual surfaces of the anterior teeth, usually maxillary canines

Front 88

Incisal rests

Back 88

- seated on the incisal edges of anterior teeth
- not used as often anymore – they present an esthetic challenge and most of the practitioners don’t use them (substituted with other types of rests).

Front 89

where are rests usually placed?

Back 89

Rests are usually placed on abutment teeth next to every edentulous space except with the RPI clasp assembly

Front 90

Guide plane and bottom of the rest should form an angle which should be :

Back 90

less than 90 degrees

Front 91

T/F - All the line angles in the preparation (especially the line angle on left marked with arrow) should be rounded.

Back 91

TRUE

Front 92

Minimal reduction for the rest should be _____mm

Back 92

1.0 to 1.5mm

Front 93

Rests may be placed on

Back 93

- Sound enamel
- Restorative material resistant to fracture & distortion
- Metal restoration
- Metal ceramic restoration

Front 94

How would you place a rest seat onto exposed dentin?

Back 94

- Place amalgam then complete rest seat preparation
- Place metal or metal ceramic restoration into which rest seat has been incorporated

Front 95

When are rest seats contraindicated?

Back 95

- Dentin
- Composite
- Porcelain

Front 96

What do you need to prepare rest seats?

Back 96

Cylindrical diamond stones to prepare the guide plane.
Inverted cone diamond stones to prepare cingulum rests.

Some other option equipment you can use if you’d like to…
Round-end tapered diamond stones help you get rid of any undercuts (if there is any).
Materials you can use for polishing or preparing rest seats.

Front 97

Buccolingual Dimensions of Molar Rest Seat

Back 97

Buccolingual
One-half width between lingual & buccal cusp tips

Mesiodistal
One quarter of the occlusal surface

Front 98

Mesiodistal Dimensions of Molar Rest Seat

Back 98

Buccolingual
One-half width between lingual & buccal cusp tips

Mesiodistal
One quarter of the occlusal surface

Front 99

Buccolingual Dimensions of Premolar Rest Seat

Back 99

Buccolingual
One-half width between lingual & buccal cusp tips

Mesiodistal
One third of the occlusal surface

Front 100

Mesiodistal Dimensions of Premolar Rest Seat

Back 100

Buccolingual
One-half width between lingual & buccal cusp tips

Mesiodistal
One third of the occlusal surface

Front 101

Advantages of Rest Seats in Restorations

Back 101

- Complete control of design
- Accommodates teeth with caries, faulty restorations or unacceptable morphology
- Longevity

Front 102

Embrasure rest seats

Back 102

- One of the types of occlusal rests is embrasure rests – try not to plan for embrasure rests unless there is a clear indication for it.
- But there are some cases you have to use them – typically being used in areas where pt has unilateral defect (only missing teeth on one side) – so since the other side does not have any missing tooth, you may have to use the embrasure rest.

Front 103

Which rests are best to use?

Back 103

occlusal > cingulum > incisal

Front 104

Lingual or Cingulum rests

Back 104

- prepared with inverted cones (diamond/carbide burs)
- Preferred over incisal rest –
closer to center of rotation of tooth esthetics advantage
- Requires adequate bulk of tooth structure for preparation
- 1.5 – 2 mm buccolingual & 1.5 mm incisogingival

Front 105

Incisal Rests

Back 105

Used when:
- Teeth show little or no enamel wear
- Esthetics is not an important consideration
- Occlusion allows adequate thickness for minor connector

Measure 2.0 mm width by 1.5 mm depth

Front 106

Which is made first... guide plane or rest seat?

Back 106

GUIDE PLANE is always made first !!!!

Front 107

What is one indication where you would use the embrasure clasp?

Back 107

pt is missing posterior teeth on one side (all the teeth behind canine is missing, on one side) and have a whole compliment of teeth on the other side

To successfully make the partial, it cannot just be made unilaterally – it has to have an extension (that will be extended) that has some support and retention from teeth from the other side.

Front 108

Major Connectors

Back 108

The component of the RPD that connects the parts of the prosthesis located on one side of the arch with those on the opposite side.

Front 109

Characteristics of Major connectors

Back 109

1-It should be made of alloy compatible with oral tissues.
2-It should be rigid and use the principles of broad distribution of stress.
3-It should not interfere with and is not irritating to the tongue.
4-It should not substantially alter the natural contour of the lingual surface of the mandibular alveolar ridge or the palatal vault.
5-It should not impinge on oral tissues when the prosthesis is inserted or removed or rotates in function.
6-It should cover no more tissues than is absolutely necessary.
7-It should not contribute to the retention or trapping of food particles.
8-It should have support from other elements of the framework.
9-It should contribute to the support of the prosthesis ( Maxillary ).

Front 110

Should major connectors be rigid?

Back 110

YES

Lateral forces are transferred through the major connector to the component on the other side, and those components can resist that lateral movement. If the major connector is flexible, it will not transfer the forces, and can break.

Front 111

Requirements of the major connectors

Back 111

1- Rigidity
2-Location:
A- Free of movable tissues.
B-Avoid impingement of gingival tissues
C-Avoid bony and soft tissue prominences during placement and removal.
D-Provision of relief ( tori, median palatal
suture ).

Front 112

In the max arch, the lateral border of the major connector should be at least ____ mm away from the gingival margin.

Back 112

In the max arch, the lateral border of the major connector should be at least 5-6 mm away from the gingival margin. This is b/c its a sensitive area and restriction can lead to loss of blood circulation, bone loss, etc.

Front 113

In the max arch, the lateral border of the major connector should be at least ____ mm away from the gingival tissues.

Back 113

3-4mm. Clearance

Front 114

Maxillary major connectors

Back 114

1- Palatal bar
2- Palatal strap
3- U-shaped palatal connector
4-Anter-posterior (A-P) connector
5- Palatal plate

Front 115

Palatal Bar

Back 115

- in order to be used, needs to be rigid.. in order to be rigid.. must be bulky & thick
- may interfere with the tongue / speech of the patient

Front 116

Palatal Strap

Back 116

- rigid. ... but NOT bulky
- minimum 8mm in width
- Made very thin. B/c it lies in different planes, it is very rigid.

Front 117

The borders of a maxillary major connector should always cross the palatal midline ... how ?

Back 117

- The borders of a maxillary major connector should always cross the palatal midline at 90 degrees.
- In other words, it should look symmetrical.
- The width of the anteroposterior dimension of a palatal strap major connector should never be less than 8 mm; otherwise it will be flexible.

Front 118

U-shaped palatal connector

Back 118

- Least desirable.
- Lack of rigidity.
- Mostly used when an inoperable torus exists

Front 119

Which type of major connector is LEAST desirable for the maxilla ?

Back 119

U-shaped palatal connector
- Lack of rigidity.
- Mostly used when an inoperable torus exists

Front 120

Palatal Plate

Back 120

- Covers half or more of the palate.
- It is a thin and broad plate.
- Increased retention by adhesion and cohesion (like in a complete denture)
- can be completely metal or a combination of metal and resin

Front 121

Antero-posterior connector (AP)

Back 121

- One of the most rigid connectors
- Could be used in almost any designs

Front 122

What is an advantage of having an acrylic/metal base compared to an all-metal base for a full palatal plate?

Back 122

- Advantage over full metal is that you can adjust the metal very easily if you have thickness of acrylic.
- It is hard to adjust full metal if patient comes back with a sore spot, for ex.
- Also, acrylic lets you relign the denture later on. For ex., if the ridge undergoes resorption you can adjust for that easily.

Front 123

Location of the major connector in relation to the teeth and gingival tissues

Back 123

Either support the connector by definite
rests on the teeth contacted, bridging the
gingivae with adequate relief, or locate the
connector far enough away from the
gingivae to avoid any possible restriction
of blood supply and entrapment of food
debris.

Front 124

Location of the anterior border of the major connector

Back 124

- Follow the outline and contour of the rugae
- Termination in the valley between the folds

Front 125

Beading the master cast

Back 125

- The process of scribing a shallow groove(0.5mm) on the maxillary master cast, outlining the palatal major connector.
- So when you place this in a patients mouth, food will not get in there because it compresses the tissue.

Front 126

Purpose of beading the maxillary
cast

Back 126

1- To transfer the major connector design to the refractory cast.
2- To provide a visible finishing line for
casting.
3 - To insure intimate, passive tissue contact of the major connector with the selected palatal tissues (peripheral seal/compression).

Front 127

Blatterfein systematic approach to major connector design

Back 127

1- Outline the stress bearing areas.
2- outline the non-bearing areas.
- Free gingival margin
- Mid palatal suture- torus
-Tissues located posterior to the vibrating line
3- Outline the connector areas.
4- Select the type of connector.
5- Unification.

Front 128

Mandibular major connectors

Back 128

1-Lingual bar
2-lingual plate ( linguoplate )
3-Lingual bar with continuous bar retainer
4- Labial bar

--> The most universally used is the lingual bar.
If there is a contra-indication to the lingual bar, you go to lingual plate or lingual bar w/ continuous bar retainer.
The labial bar is used very rarely.

Front 129

what is the most commonly used mandibular major connector?

Back 129

--> The most universally used is the lingual bar.
If there is a contra-indication to the lingual bar, you go to lingual plate or lingual bar w/ continuous bar retainer.
The labial bar is used very rarely.

Front 130

Lingual Bar

Back 130

- Half pear shaped in cross section.
- Flat on the tissue side.
- Superior border 3-4 mm away from the free gingival margins.
- 4mm in width.
- Greatest bulk in the lower third.
- Tapered superiorly.
- NO TISSUE CONTACT
- Made of 6 gauge wax (reinforced with 24 gauge
wax).

Front 131

Does the lingual bar touch lingual gingival tissues?

Back 131

NO !!!!

--> if you don't have space,

Front 132

Determination of the height of the floor of the mouth

Back 132

An important factor in designing the mandibular connector is to know exactly how deep the lingual sulcus is w/o impinging on the movement of the lingual frenum.
There are two techniques we have to achieve this:
1. Use of the periodontal probe: determine and measure the depth of the sulcus intra-orally.
2. We can border mold the individualized impression tray to register the depth of the sulcus and the movement of the lingual frenum.

Front 133

Lingual Plate ( linguoplate)

Back 133

- Inferior border same as lingual bar.
- Superior border on the middle third of the lingual surface of the teeth.
- Terminal rests at each end.

--> Lingual plate is the next favorable major connector after the lingual bar. It is used when the lingual bar is contra-indicated.

Front 134

Indication of linguoplate

Back 134

1. So remember that if you have less than 8 mm of space, you can't use the lingual bar. Obviously, if the patients lingual frenum is too high, then you won't have the 8 mm of space and would therefore opt for the lingual plate.
2. Since the lingual plate attaches to the middle third of teeth, it is indicated when you want to stabilize periodontally week teeth.
3. It can be a contingency plan, i.e. when you want to replace teeth in the future.
4. If you have excessive vertical ridge resorption like in a Class I edentulous patient.

Front 135

Continuous bar retainer

Back 135

1- When a linguoplate is otherwise indicated but excessive interproximal block-out is required.
2- When diastema exists between the teeth low enough where a lingual bar would be seen between the teeth

- The continuous bar retainer is a lingual bar to which a continuous bar is added. Another way of describing it is having a lingual plate to which a window in the middle was opened.
- The continuous bar is in the middle third of the tooth.

Front 136

when is a continuous bar retainer indicated?

Back 136

1- When a linguoplate is otherwise indicated but excessive interproximal block-out is required.
2- When diastema exists between the teeth low enough where a lingual bar would be seen between the teeth

- The continuous bar retainer is a lingual bar to which a continuous bar is added. Another way of describing it is having a lingual plate to which a window in the middle was opened.
- The continuous bar is in the middle third of the tooth.

Front 137

What is a requirement for lingual plate and continuous lingual bars?

Back 137

- Lingual plate and continuous lingual bar should be supported by terminal rests.
- Connector borders resting on unprepared tooth surfaces can lead only to slippage of the prosthesis along inclines, to orthodontic movements of the teeth, or both

--> W/o a rest preps, the two implant inclined surfaces are going to slide over each other and the major connector will push the teeth in the opposite direction.

Front 138

What will happen if you do not support lingual plate and continuous lingual bar by terminal rests?

Back 138

W/o a rest preps, the two implant inclined surfaces are going to slide over each other and the major connector will push the teeth in the opposite direction.

Front 139

Labial Bar

Back 139

- This placement on the labial ridge is very uncomfortable.
- You will be able to see the lip of the patient bulging out.
- The labial bar is mostly used when you have teeth that are excessively recline VERY lingually.
- The picture shows I-bars coming from the labial bar, an even rarer RPD type.

Front 140

indications of the labial bar

Back 140

Indications of the labial bar:
1. Extreme lingual inclination of the teeth.
2. Inoperable mandibular tori.

Front 141

Systematic approach to mandibular major connector design

Back 141

1. First, you outline the basal support/seat areas
2. Outline the inferior border of the major connector
3. Outline the superior border of the connector (w/ consideration of a 3mm distance from the free gingival margin)
4. Unification of the design.

Front 142

After measuring the lower border of the bar to the free gingival margin.... If you have ___ mm+, use lingual bar. If not, use lingual plate.

Back 142

7-8

Front 143

Minor connector

Back 143

Part of the partial denture that connects different components to the major connector
--> should be connected by a right angle

Front 144

How should minor connectors be placed in relationship to the major connectors.

Back 144

Minor connectors should be placed at right angles of the major connectors.

Front 145

In the mand arch, the minor connector goes how far down the length of the edentulous space?

Back 145

In the mand arch, the minor connector goes only 2/3rds of the anteroposterior length of the edentulous space

Front 146

Tissue Stop

Back 146

Part of the retention meshwork that contacts the ridge and prevents distortion of the framework during processing of the acrylic resin.

Tissue stops basically prevents the rotation and compression of metal meshwork and packing of the factory resin.

Front 147

Finishing line

Back 147

Junction between the metal framework and the acrylic denture base
--> It should be a butt joint

Front 148

Finishing line has to be _________

Back 148

Finishing line has to be a butt joint.

Front 149

Direct retainer

Back 149

Any unit of a removable partial denture that engages an abutment tooth in such a manner as to resist displacement of the prosthesis away from the basal seat tissues

Front 150

Intracoronal Direct Retainers

Back 150

use of frictional resistance
between 2 parallel wall = provide retention
---> "Lock & Key-principle"

**There HAS to be a crown on the adjacent tooth in order to support the lock-and-key mechanism
--> would break a real tooth

Front 151

What is one restriction of an intracoronal attachment?

Back 151

There HAS to be a crown on the adjacent tooth in order to support the lock-and-key mechanism
--> would break a real tooth

Front 152

Advantages of intracoronal attachments

Back 152

- Esthetics (will not show clasp)
- Favorable forceq distribution

Front 153

Disadvantages of Intracoronal attachments

Back 153

- Preparations and castings
---> Must crown prep the abutment, but what if it's a sound tooth?
- Complicated clinical and laboratory
---> Must be parallel, require very precise procedures
procedures
- Wear and loss of retention
- Difficult to repair and replace
- Least effective on short teeth
- Difficult to place completely within tooth circumference

Front 154

Limitation of the use of Intracoronal attachments

Back 154

- Size of the pulp
---> young patient or others with larger pulp
- Length of the clinical crown
---> shorter = less contact
- Cost (more expensive)
- Distal extension cases
---> rigid components will loosen up very quickly

Front 155

What is the major difference between a circumferential clasp and a bar clasp ?

Back 155

- circumferential clasp appraoches the undercut from the occlusal direction

- bar clasp approaches the undercut from the gingival direction

Front 156

circumferential clasp appraoches the undercut from the _____ direction

Back 156

- circumferential clasp appraoches the undercut from the occlusal direction

- bar clasp approaches the undercut from the gingival direction

Front 157

bar clasp approaches the undercut from the ________ direction

Back 157

- circumferential clasp appraoches the undercut from the occlusal direction

- bar clasp approaches the undercut from the gingival direction

Front 158

clasp retention

Back 158

- Once seated, clasp should have no force exerted on the teeth
---> Passive retention
- Over retention by opening up minor connector will exert excessive force on the teeth, also it will not equalize

Front 159

Amount of clasp retention

Back 159

1) Size of the angle of cervical convergence.
2) How far into the angle of cervical convergence the clasp terminal is placed.
3) Flexibility.

Front 160

Factors influencing the flexibility of the clasp arm

Back 160

- Length.
- Diameter.
- Cross sectional form.
- Material used.
- Method of fabrication.

Front 161

How does the length of the clasp arm, affect its flexibility?

Back 161

- Flexibility is directly proportional to the length
- Longer the clasp, flexibility is higher
--> Thus deeper into the undercut to gain same retention

Front 162

How does the diameter of the clasp arm, affect its flexibility?

Back 162

- Flexibility is inversely proportional to the diameter
- Thinner is more flexible
- Thicker is less flexible

Front 163

How does the cross-sectional form of the clasp arm, affect its flexibility?

Back 163

Circle, --> flexibility is higher
(open up into all the directions)

Half Circle, --> flexibility is less

Front 164

How does the material used in the clasp arm, affect its flexibility?

Back 164

1-Chromium Cobalt --> material of choice nowadays
2- Type IV gold --> more flexible and expensive

Front 165

How does the method of fabrication of the clasp arm, affect its flexibility?

Back 165

1- Cast clasp arm
--> microscopic structure lessen flexibility


2- Wrought Wire clasp arm
--> higher flexibility

Front 166

Clasp Assembly

Back 166

- Retentive clasp arm
- Reciprocal clasp arm
- Rest
- Minor connector

Front 167

Basic principle of clasp design

Back 167

- More than 180 degrees tooth coverage.
- Provision of an occlusal rest.
- Reciprocation.
- Guide planes.
- Stress breaking action ( distal extension).
- Location of retentive and reciprocal components.

Front 168

Clasp has to cover more than ______ degrees from diverging to converging walls

Back 168

180

Front 169

If Occlusal rest is not present...

Back 169

1. Tissue compression under the denture base
2. Loss of contact of denture and sound teeth
3. The location of reciprocal & retentive clasp will not be maintained

Front 170

Ideal Location of the survey line **

Back 170

The ideal location of the survey line is in the middle of the middle third of the tooth in the near zone and slightly lower in the far zone.

Front 171

The ideal location of the survey line in the near zone is

Back 171

The ideal location of the survey line is in the middle of the middle third of the tooth in the near zone and slightly lower in the far zone.

Front 172

The ideal location of the survey line in the far zone is

Back 172

The ideal location of the survey line is in the middle of the middle third of the tooth in the near zone and slightly lower in the far zone.

Front 173

Types of Circumferential Clasps

Back 173

1- Basic circumferential.
2- Embrasure clasp.
3- Ring clasp.
4- Back action clasp.
5- Reverse action clasp.
6- Half and half clasp.
7- Multiple clasp.

Front 174

Where is the retentive clasp arm usually?

Back 174

1/3 bellow and 2/3 above the survey line

usually on the buccal side of the tooth

Front 175

Where is the reciprocal clasp arm usually?

Back 175

usually on the lingual

1. Equalize lateral forces exerted by the Retentive Clasp
2. Also stabilize partial denture cross arch

Front 176

When would you use an embrasure clasp?

Back 176

mostly used when you don't have any edentulous spaces in the back

Front 177

how would you prepare an embrasure clasp

Back 177

at the contact... both teeth should be slightly reduced occlusally , but NOT enough to break contact !!!

Front 178

half and half clasp

Back 178

- no real indication for the use of this
- basically, they cut and separate the 2 halfs of the circumferential clasp

Front 179

multiple clasp

Back 179

- indicated in situation when you dont have an edentulous space

Front 180

combination clasp

Back 180

- also used in distal extension cases
- posterior there is no abutment.. so there is tissue support

Front 181

advantages of combination clasp

Back 181

- flexibility
- adjustability
- esthetic advantage
- minimum tooth coverage

Front 182

disadvantages of the combination clasp

Back 182

- extra lab work
- easily distorted

Front 183

bar clasp

Back 183

a clasp that originates from the framework and approaches the undercut from a gingival direction

Front 184

Types of Bar Clasps

Back 184

- I-Bar
- T-Bar
- Y-bar
- Modified T-bar

Front 185

Before submitting the case to the laboratory, there are a few things you need to prepare & have ready:

Back 185

1) Work authorization
2) Properly surveyed diagnostic cast
3) Properly articulated master cast (reproducing hard and soft tissues)

Front 186

Beading must be how deep ?

Back 186

- 0.5 mm deep
- Produces a raised edge at the border of the major connector
- Ensures positive contact with the palatal tissues to minimize food impaction

***maxilla ONLY (mandibular mucosa doesn't tolerate pressure that well.)

Front 187

do you bead on the maxilla, mandibke, or both ?

Back 187

- 0.5 mm deep
- Produces a raised edge at the border of the major connector
- Ensures positive contact with the palatal tissues to minimize food impaction

***maxilla ONLY ( mandibular mucosa doesn't tolerate pressure that well. )

Front 188

What is the point of "beading" ?

Back 188

- Creates a raised border on the periphery of the connector w/ palatal tissues to minimize food impaction

- major connector for the mandible is blocked out.. So it will be AWAY from the tissues… maxillary is INTIMATE with the tissues

Front 189

Blockout andRelief

Back 189

Surveyed for hard and soft tissue undercuts

Surface sealer to protect design during blockout and duplication
--> acetone, diethyl phthalate, and cellulose acetate

Front 190

What materials do you use for a blockout and relief?

Back 190

Surveyed for hard and soft tissue undercuts

Surface sealer to protect design during blockout and duplication
--> acetone, diethyl phthalate, and cellulose acetate

Front 191

Arbitrary blockout

Back 191

Arbitrary blockout to minimize distortion/tearing during duplication (reversible hydrocolloid rebound is < 3 mm)

Front 192

Duplication

Back 192

Make a replica of the model you just blocked out. This replica is where you'll make the framework.

Flask is being used for duplication purposes. Bottom portion of flask is used to attach and seal master casts. Top portion of flask then attached over.

Front 193

Duplicating colloids

Back 193

- Can be remelted and used repeatedly
- Working temperature of 63°C (145°F) ‐lower than melting temperature of blockout material

Front 194

Refractory materials/ Investments Properties

Back 194

- Higher melting temp than the melting range of the alloy
- No chemical reactions between the alloy and the investment
- Should yield a fine surface finish on the casting
- Permeable to gases molten metal displaces air as it flows.
- Adequate strength to withstand the incoming alloy
- Should be expandable to compensate for cooling shrinkage

Front 195

Plaster‐bonded (low‐heat) investments

Back 195

Used with alloys with melting temperatures up to about 700‐1000ºC (primarily gold casting alloys)

If subjected to higher temperatures, may cause porosity or corrosion.

Front 196

Phosphate bonded (high‐heat) investments

Back 196

- Used with chromcobalt alloys with melting temperatures of 1400-1500ºC
- Set by way of an acid‐base reaction
- Must be vacuum mixed

Front 197

Ti investments

Back 197

- Used with Ti ,melting temperatures of 1700ºC
- Based on alumina, zirconia, or magnesia

Front 198

Refractory cast

Back 198

Drying oven at 93°C (200°F) for 30 to 60 minutes

Trimmed on DRY cast trimmer to within 6 mm of the proposed design

Dipped into beeswax at 138°C to 149°C (280°F to 300°F) for 15 seconds to seal up the surface

Front 199

Design transfer

Back 199

Freehand design transfer

Ledges created in blockout wax shows the positions of retentive clasp tips

Front 200

Burnout during wax elimination

Back 200

- drives off moisture
- vaporizes / eliminates the pattern
- expands the mold to compensate for contraction of the metal on cooling.

Front 201

Electropolishing

Back 201

- Anodic dissolution or "reverse plating“
- Atoms from rough projections dissolve first
- Orthophosphoric acid heated to 49°C (120°F) to 60°C(140°F)
- 1 square inch of surface area = 2 amperes of current for 6 minutes (average is 6 amp for 6 min)

Front 202

Final polish

Back 202

- Rubber wheels
- Polishing compounds on rag and felt wheels
- Ultrasonic cleaning
- Returned on the master cast

Front 203

Wax elimination

Back 203

- Boiling water for 5 minutes
- Flushed with boiling slurry

Front 204

Packing

Back 204

- Polymer‐monomer ratio is 3:1 by volume
- Mixed for 30 seconds

Tightly closed for 1 minute or until doughlike

Front 205

During packing, what is the polymer:monomer ratio?

Back 205

- Polymer‐monomer ratio is 3:1 by volume
- Mixed for 30 seconds

Tightly closed for 1 minute or until doughlike

Front 206

Long cure cycle processing the RPD

Back 206

Long cure cycle
- curing unit with room‐temperature water
- temperature is raised slowly to reach 74°C (165°F) in 1 hour
- maintained for 7 hours
- brought to a boil for 30 minutes

Short cure cycle
- From room‐temperature raised to 74°C (165°F) in 1 hour
- maintained for 90 minutes
- brought to a boil 30 minutes

Front 207

short cure cycle processing the RPD

Back 207

Long cure cycle
- curing unit with room‐temperature water
- temperature is raised slowly to reach 74°C (165°F) in 1 hour
- maintained for 7 hours
- brought to a boil for 30 minutes

Short cure cycle
- From room‐temperature raised to 74°C (165°F) in 1 hour
- maintained for 90 minutes
- brought to a boil 30 minutes