Final practical pdf - Final practical

ساليدات امتحان العملي

الصناعة الفصل االول

اعداد

سلطان الصفار

Introduction and

classification

Prosthetics & Prosthesis

Consequences of tooth loss

Removable
partial
dentures



2.Fixed

restoration

s –



conventio

nal

bridges

Treatment

options

Components of Removable Partial dentur

modifications

classification

modifications

Rests and rest seats

Occlussal Rest seat

(Conventional form)

Intracoronal
(precision)
rest

Rest & its

function

fulcrum line

&Indirect retention

& & rest function in

preventing rotation

The floor of the rest seat

should be inclined

towards the center of the

tooth, so that the angle

formed by the rest and

the minor connector

should be

less than 90°

The floor of the rest

seat should be

concave or spoon

shaped to create a

ball-and socket-type

of joint

The marginal ridge must be

lowered and rounded to permit a

sufficient bulk of metal to prevent

fracture of the rest from the minor

connector (1 to 1.5 mm)

Double

Embrasure or

inter proximal

rest

Double

Embrasure or

inter proximal

Rest Seat

EXTENDED OCCLUSAL REST

In Kennedy Class II, modification 1,

and Kennedy Class III

situations in

which the most posterior abutment

is a mesially tipped molar, an

extended occlusal rest should be

designed and prepared to

minimize further tipping of the

abutment and to ensure that the

forces are directed down the long

axis of the abutment.

This rest

should extend more than one half

the mesiodistal width of the tooth,

be approximately one third the

buccolingual width of the tooth,

and allow for a minimum of 1-mm

thickness of the metal, and the

preparation should be rounded

with no undercut or sharp angles .

Cingulum or

Lingual Rest

Seats

from the lingual

aspect is a broad

inverted "V'

From the incisal

view the rest seat

is broadest at the

central aspect of

the canine

(approximately

( 1mm).

The borders of

the rest seat are

slightly rounded

to avoid sharp

line angles in its

preparation

Positive

rest seats

The cingulum rest seat should be prepared in the bulk of the cingulum to

minimize tooth reduction.

The cavosurface should be less than 90° to prevent orthodontic

movements of the tooth

Cingulu

m rest

False

cingulu

m rests

Too high

cingulum

rest

preparati

(un

necessary

tooth

reduction

Preparation

Too Low

(excessive

tooth

reduction)

The interocclusal relationship of a maxillary tooth

with the incisal edge of the opposing mandibular

tooth.

Mounted diagnostic casts should be used to assess this

relationship The cingulum rest seat preparation draw a line on

the lingual surface of the maxillary abutment should be 1.5-2.0

mm below this line to allow for adequate framework strength.

Maxillary Cingulum Rest Seats overlapping

. When a

deep vertical overlap exists, care must be taken to

ensure that the mandibular tooth does not prematurely

contact the area of the planned metal framework.

Rounded rest, prepared

on mesial of the canine

teeth when typical

cingulum rest is

contraindicated

Incisal Rest

Inferior to

lingual rests mechanically

& esthetically not be used

unless it is impossible to

place a lingual rest seat or

a composite bonded rest

seat. It is used as indirect

retainer

Incisal rest seat

or preparation

surveying

Manual

Dental

surveyor

CAD/CAM SYSTEM.

With intra oral

surveying camera

B-Vertical Upright Column

C-Cross Arm with Spindle

Housing

D-The Vertical Spindle

With Tool Holder

E- Screw To Lock The

Spindle

F- Tool adaptor Holder

G- Surveying tool holder

J- Model Clamp

K- Model table lock nut

L- Model rotating ball &

socket

M- Ball rotating ring

N- Tool Rack

O- Storage Compartment

P- Model lock nut

Parts of a Dental

Surveyor

Surveying

Table

Surveying

Arm(all)

Analaysing

rod

Carbon Markers

Wax Trimmer

Height of

Contour (HOC)

or survey line

survey line

Tooth

Undercuts

Soft Tissues or bony

Undercuts

(on lingual

side of ridge)

Angle of

Cervical

Converge

nce

Path of

insertion

(or

removal)

Types of

undercuts

Preperation Of Guiding Planes

Guidin

planes

Guiding plane is Most effective when:

A- Parallel to each other
B- More than one common axial surface

C- Directly opposing each other

D- Prepared on several teeth

E- Cover a large surface

area(proximal & lingual)

Long

Cylindrical

Carbide or

Diamond)

Retentive Areas

Retentive arm should have a
different path of escapement

than guiding plane (path of

removal), so retentive arm must

be forced to flex over a convex

surface during placement and

removal (retention)

For a clasp to be retentive, its

path of escapement must be

other than parallel to the path

of removal of the denture itself.

Retentive

undercuts

equalized

interference

Prosthesis must be

designed so that it

may be placed and

removed without

encountering

tooth

soft tissue

interference

Interference

Bony

undercuts

Esthetics

A path of insertion should be

selected to provide the most esthetic placement
of artificial teeth and the least amount of
visible metal on the abutment teeth . the
retentive undercut and the height of contour
are not placed too far occlusally

Direct retainers

Intracoronal

(precision

attachemen

ts)

Extracoronal

retainer

(Infrabulge clasp)

the angle of the
cervical convergence

How far is the clasp

terminal is placed in angle

of cervical convergence

Diameter of

clasp arm

Cross sectional form of the clasp ar

round, half round )

reciprocati

The

principle of

encirclemen

Stabilizing and

reciprocal

components must

be rigidly connected

bilaterally (cross-

arch)

Each retentive terminal should be

opposed by reciprocal component

capable of resisting any transient

pressures exerted by the retentive

arm during placement and removal

Suprabulge

circumferential or

C-clasp (direct

retainer)

Ring

clasp

Ring clasp with

auxiliary bracing

arm*

Back-action

clasp*

Multiple

Clasp*

Half-and-

half clasp*

Reverse-

action

clasp*.

Combinatio

clasp*

C-claspال

يفضل

كتابة جميع

االنواع بنفس صيغة

(*)

Bar clasps

RPI AND RPA VS

CONVENTIONA

RPI

Clasp retention is base on

the resistance of the metal.

For a clasp to be retentive

<it must be placed in an

undercut area of the tooth

where it is forced to deform

upon application of vertical

force

Indirect retainers

Free end saddle partial

denture with indirect retention

FULCRUM LINE

Indirect

retainers should be placed

as far as possible from the

distal extension base

Location of fulcrum lines for

different classes of RPDs

1)Class1-passes through most

posterior abutments

2) Class2-passes diagonally

through most posterior teeth

on one side and abutment on

distal extention side

3) Class3-passes through two

principal abutments

4)Class4-passes through two

abutments adjacent to the

edentulous

space

Effectiveness and Placement:

- Usually it is a rest seat placed anterior the the fulcrum line on the side opposite the

extension base. Theoretically, the further anterior the rest seat is placed the more

effective it is. The rest seat is usually located on a canine or first premolar mesial fossae.

Auxiliary

occlusal rest

indirect retainer

REST

(CINGULUM

REST OR

LINGUAL REST

indirect

retainer

CANINE EXTENSION FROM

THE OCCLUSAL REST

Cingulum

bars

( Continuous

bars) and

Linguoplates

Modification

Areas as

indirect retainer

Rugae

Support

Maxillary

Major Connector

Gingival protection

Cross-Arch Stabilization

principle in major

connectors

(Counterleverage

To Increase Rigidity

Increase the bulk as the length increases

Corrugate linguo-plate or rugae areas

Non-Interference with the Soft

Tissues

It does not interfere with the tongue

and not impinge on oral tissue

when the restoration is placed,

removed, or rotates in function

Avoid terminating on Free gingival

margin

Minimize

Food

Impaction

Eliminate "traps"Locate margins away from

the FGM

or large concavities where food can collect

a major connector must promote patient comfort

Smooth transition from connector to denture base - butt joint

promote patient comfort

Line angles and edges should be smooth and rounded

Borders should not interfere with speech

Single palatal bar

Single palatal

strap

Single Palatal Strap

Strap should

be 8mm wide

approximately

as wide as the

combined

width of a

maxillary

premolar and

first molar

Single Palatal Strap

Usually use for Class III

Combination anterior and posterior

palatal strap type connector

Use in most

cases

Especially

torus

palatinus

Anterioposteior palatal strap

PALATAL MAJOR CONNECTOR

COMPLETE PALATAL

COVERAGE MAJOR

CONNECTOR

Or The complete palatal

plate

U-SHAPED PALATAL

MAJOR CONNECTOR

Use only where torus

prohibits other connectors

Flexes,

impinging

on soft

tissue

U-SHAPED PALATAL

MAJOR CONNECTOR

Use only where torus

prohibits other connectors

(

U-Shaped or "Horse-Shoe"

Palatal Connector

)

Never

use

unless absolutely necessary

Combination Anterior-

posterior palatal bar

Anterior-Posterior Palatal

Bar

Beading of the

Maxillary Cast

Special Structural Requirements of

Mandibular major connectors:

1. relief must be routinely provided

between mandibular major

connector and the soft tissue.

2. because of the need for relief under

all mandibular major connectors,

Beading is never indicated

Amount of relief depend on:

Determination of the

relative height of the

floor of the mouth

Lingual Bar

Characteristics and

location

(1) Half-pear shaped with

bulkiest portion inferiorly

located.

(2) Superior border

tapered to soft tissue.

(3) Superior border

located at least 4 mm

inferior to gingival margins

and more if possible.

(4) Inferior border located

at the ascertained height

of the alveolar lingual

sulcus when the patient's

tongue is slightly elevated.

MANDIBULAR

LlNGUOPLATE
( Lingual plate)

correct

incorrect

Characteristics and Location

(

) Half-pear shaped with bulkiest portion

inferiorly located.

(2)

Thin metal apron (sold piece) extending

superiorly to contact cingula of anterior teeth

and lingual surfaces of involved posterior

teeth at their height of contour.

(3)

Apron extended interproximally to the

height of contact points, i.e., closing

interproximal spaces.

(4)

Scalloped contour of apron

as dictated by interproximal

blockout.

(5)

Superior border finished and

knife edged to continuous

plane with contacted teeth.

(6)

inferior border at the

ascertained height of the

alveolar lingual sulcus when

the patient's tongue is

slightly elevated

lingual plate must be

supported by rests located

no farther posterior than

the mesial fossae of first

premolars

lingual plate may include "step

backs" to minimize or eliminate the

appearance of metal

Sublingual

bar major

connector

sublingual bar major connector

Characteristics and Location

A modification of the lingual bar that has been demonstrated to be useful when the height

of the floor of the mouth does not allow placement of the superior border of the bar at

least 4 mm below the free gingival margin is the

sublingual bar.

The bar shape remains essentially the same as that of a lingual bar, but placement is

inferior and posterior to the usual placement of a lingual bar, lying over and parallel to

the anterior floor of the mouth.

CINGULUM BAR
(continuous bar)

Characteristics and location

(l)

Thin, narrow, ( 3 mm) metal strap located on

cingula of anterior teeth, scalloped to follow
interproximal embrasures with inferior and
superior borders tapered to tooth Surfaces.

(2)

Originates bilaterally from incisal , lingual,

or occlusal rests of adjacent principal
abutments.

MANDIBULAR LINGUAL BAR WITH CINGULUM

BAR (Double lingual bar, Kennedy

bar)

Characteristics and location

(1) Conventionally shaped and located Same as lingual

bar major connector component when possible.

(2) Thin, narrow (3 mm) metal strap located on cingula

of anterior teeth, scalloped to follow interproximal

embrasures with inferior and superior borders

tapered to tooth surfaces.

(3) Originates bilaterally from incisal, lingual, or occlusal

rests of adjacent principal abutments

MANDIBULAR LINGUAL BAR

WITH CINGULUM BAR (Double

lingual bar, Kennedy bar)

The swing-lock

design

is a variation of

the labial bar.

Hinge at one

end and

locking

device at the

opposite end

Minor

Connectors

The minor

connector:

• Connects

components to

the major

connector

• Direct retainer

• Indirect retainer
• Rest

Minor connector

must not impinge on marginal gingival tissues

Slight relief is required when crossing the gingival margin

especially in tooth-mucosa borne dentures.

Minor connectors should be located at least

5mm

from other vertical components.

Embrasure

Minor

Connectors

Between two adjacent

teeth

Gridwork minor connectors

that connect the denture

base and teeth to the major

connector.

Mesh type

Triangular shaped in cross

section

Joins major connector at

right angles

Relief placed so connector

not directly on soft tissue

Proximal minor connector

mesial and distal minor

connectors and proximal plates

adjacent to the edentulous areas

should swing back to join the

major connector in a rounded

acute angle in order to increase

gingival exposure.

Lattice Type

Gridwork Minor Connectors

Open lattice work

mesh types

Bead, wire, or nail-head minor connectors

Gridwork Relief

Usually one thickness of baseplate wax is about

1 mm

of relief sufficient

The minor connector for the mandibular

distal extension base should extend

posteriorly about two-thirds the length of

the edentulous ridge and should have

elements on both lingual and buccal

surfaces.

Mandibular Gridwork Design

هنا

ايض

Minor connectors for maxillary distal

extension denture bases should

extend the entire length of the residual

ridge and should be of a ladderlike

and loop design.

Those that serve as an approach arm for

a vertical projection or bar-type clasp.

The junction of gridworks to the major

connector should be in the form of a

butt joint with a slight undercut in the

metal. The angle formed by the metal

at this juncture must not be greater

than 90 degrees.

If these butt joints occur on the

outer aspect of the major

connector they are called external

finish lines; if they are on the

internal or tissue side of the major

connector ,they are internal finish

lines .

Angle the

finish line

forms with

major

connector

– less than

90 degree.

90-degree butt-

type joints

Tissue stop

Closure of the flask under

hydraulic pressure can

causes distortion of the

framework, pushing it

tissue ward

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