Raju major n minor connectors/dental courses

Maj or and minor
connect ors
INDIAN DENTAL ACADEMYINDIAN DENTAL ACADEMY
Leader in continuing Dental EducationLeader in continuing Dental Education
www.indiandentalacademy.com

CONTENTS
 Introduction
 Definition
 Functions of major and minor connectors
 Basic principles of design of a major and minor
connector
 Types of major and minor connectors
 Tissue stops and finish lines
 Review of literature
 Summary and conclusion
 References

Definition:Definition:
Major connectorMajor connector:: The part of removable partialThe part of removable partial
denture that joins the components on one side ofdenture that joins the components on one side of
the arch to those on the opposite sidethe arch to those on the opposite side

COMPONENT PARTS
1. Major connector
2. Minor connector
3. Occlusal rests
4. Direct retainer
arm
5. Stabilizing or
reciprocal
component
6. Indirect retainer

MAJOR CONNECTORS
 Connects parts of the
Prostheses located on one
side of the arch to those on
the opposite side
 All other parts of the
Partial Denture are
attached to it either
directly or indirectly.

REQUIREMENTS
To function effectively and minimise potentially damaging
effects, All major connectors must be
1. be rigid
2. provide vertical support and protect the soft tissues
3. provide a means of obtaining indirect retention where
indicated
4. Provide a means for placement of one or more denture
bases .
5. Maintain patient comfort.

 Not create food entrapment areas, as far as possible self
cleansing.
 Should not interfere with and is not irritating to the
tongue.
 Should not impinge on oral tissues when the restoration is
placed, removed or rotates in function.
 Covers no more tissues than is absolutely necessary.

Design considerations for major connectorDesign considerations for major connector

MAXILLARY MAJOR CONNECTORS
1. Palatal Bar
2. Palatal Strap
3. Antero-Posterior palatal Bar
4. Antero-Posterior palatal strap/ closed horseshoe
5. Horse shoe/ U shaped connector
6. Palatal plate

PALATAL BAR
Narrow half-oval bar with thickest
point at the center.
1. For many years it was widely
used
2. Now Mainly used as interim
partial denture

DISASDVANTAGES
1. Bulky, difficult for
patient
2. Derives little vertical
support
3. Limited to replacing
one/two teeth on either
side of arch Only in
Class-3 arch
4. Should Not be placed
anterior to II premolar
( bulk produces
discomfort and alteration
of speech )

PALATAL STRAP
1. Most widely used
2. Strap extends over 3
planes
3. Width increases with
edentulous span
4. More rigid with less bulk 8 mm

Indications
1. Class 2 arches
2. Class 3 arches.
3. should not be used
in Class 1

advantages
1. “ L “ beam principle
2. Excellent resistance against
bending and twisting forces
3. Enhanced retention due to
increased adhesion and
cohesion
4. Strong so it can be kept thin
Disadvantages
Papillary hyperplasia
Large palatal coverage

ANTERO-POSTERIOR PALATAL BAR
 Excellent rigidity, strong
 L-beam effect
 Limited soft tissue
coverage
 Provides less support,
completely dependant on
remaining teeth

INDICATIONS
1. Indicated in pts with
large palatal torus where
surgery is ruled out
2. support is not a major
consideration
3. Anterior and posterior
abutments are widely
separated
4. Class 2 modification 1
5. Class 4

DISADVANTAGES
 Not first choice connector
 Bulky and interfere with
phonetics
 Contraindicated in
patients with reduced
periodontal support
 Contraindicated in high
narrow vault-phonetics

CLOSED HORSE-SHOE
A-P PALATAL STRAP
1. Most commonly used
2. Structurally rigid
3. Better support than A-P Bar
4. Indicated in Class 1 & 2
arches where more teeth to be
replaced
5. Tori
6. Encirclement provides rigidity
7. L beam principle
20x15 mm

disadvantages
 Interference with
phonetics
 Extensive length of
borders may cause
irritation to tongue

Horse-shoe/ U shaped connector
1. Borders must be 6mm
from gingival margin or
extend onto lingual
surface
2. medial borders should
extend at junction of
horizontal & vertical
slopes of hard palate
3. Symmetric on both sides
Indications
1. Tori is present
2. Class 4

advantages
1. Reasonably strong
2. Derives vertical support
from tissues of hard
palate
3. Hard palatal suture line
& inoperable tori
4. Moderate indirect
retention and support

disadvantages
1. Less rigid, not used in
Cl.1 & 2.
2. Tendency for connector to
deform

PALATAL PLATE TYPE CONNECTOR
INDICATIONS
 In most situations in which
only some or all anterior
teeth remain
 Class II arch with a large
posterior modification
space and some missing
anterior teeth

PALATAL PLATE
1. Ultimate rigidity & support, covering
half/more of hard palate
2. Post border – junction of hard & soft
palate
3. Class 1 & Class 2 with modifications
4. Remaining teeth are periodontally
compromised
5. Thermal conductivity
6. Metal exhibits less porous surface –
resistance to microorganisms
colonisation
7. Heavy occlusal forces , flat/flabby
ridges, shallow vault, transition to CD,
cleft patients

Disadvantages
1. Extensive coverage-soft tissue reaction
2. inadequate oral hygiene
3. Soft tissue hyperplasia
4. Problems with phonetics

BEADING
 Denotes scribing of a
shallow groove on the
maxillary master cast
outlining the palatal major
connector exclusive of
rugae areas.
 Depth & width of 0.5 to
1mm
 Fades out 6mm from
Gingival margin

Purpose of beading
1. To transfer the major
connector design to the
investment cast
2. To provide a visible finish
line for the casting

3) To ensure intimate tissue
contact of the major
connector with selected
palatal tissue
4) Prevents food debris under
the connector
5) Enhances retention &
stability

Design procedure for maxillary majorDesign procedure for maxillary major
connectorconnector

Summary of Indications
1. Perio support of remaining teeth weak – Palatal
strap/complete palate
2. Good periodotal support – Palatal strap/A-P bar
3. Long distal extension bases – Complete palatal
plate/antero posterior palatal strap
4. Cl. 4 – Horseshoe, Closed horseshoe, complete palate
depending on no. & location of posterior missing teeth,
support of remaining Teeth, and opposing occlusion

 Inoperable torus – Horseshoe, closed A-P Bar
 Horse shoe connector should be used very sparingly
 Single palatal bar rarely indicated.

MANDIBULAR
 Lingual bar
 Lingual plate
 Double lingual bar/ Kennedy bar
 Labial bar

STRUCTURAL REQUIREMENTS
1. Long and relatively narrow because of space limitations
2. Rigidity without addition of bulk
3. Relief should be provided . Amount of relief depends on
type of connector.
4. Beading is never indicated.

Lingual bar
 Most frequently used, half pear shaped
 Atleast 8mm space required

4 mm
3 mm

1. Half pear shaped with bulkiest
portion inferiorly located.
2. Superior border tapered to soft
tissue, located 4 mm inferior to
gingival margins.
3. Inferior border located at the
asertained height of the alveolar
lingual sulcus when the patients
tongue is elevated
Lingual bar

 Simplicity in design and construction
 Indicated in all tooth supported dentures
 Minimal contact with the remaining teeth and
soft tissues

Linguoplate
Pear shaped lingual bar with metal extending
onto lingual tooth surface

 Adequate blockout & relief
under Major connector
 Superior border placed
above cingula to close space
upto contact points
 Always supported by a rest
located no farther posterior
than mesial fossa of 1st
premolar

Lingouplate - Indications
When lingual frenum is high / space available
for lingual bar is limited (Min 8mm) gingival recession,
High muscle attachments, high frenum attachments

Lingual plate
1. Maximum rigidity
2. In Class 1, where residual ridges
have undergone excessive vertical
resorption
3. Stabilizing periodontally
weakened teeth
4. Linguoplate modification with
incisal rests to prevent mand. ant
teeth from supraeruption
5. Future replacement of one/more
anterior teeth will be facilitated by
addition on retention loops

Disadvantages
1. Extensive coverage may lead to decalcification of enamel
surfaces
2. Irritation of soft tissue with poor oral hygiene
Advantages
1.Most rigid and stable
2.Provides indirect retention when rests are provided
3.Additional tooth can be added

Double lingual/ Kennedy Bar
 Upper bar 2-3 mm in height
and 1 mm thick
 It should follow scalloped
appearance
 Rests placed for indirect
retention.
 Indicated primarly when
contact with remaining
mandibular teeth is
indicated, but open
embrasures exists.

AdvantagesAdvantages
1. Indirect retention in antero posterior direction when supported
by rests
2. Horizantal stabilisation since stress is transferred to teeth
3. Since gingival tissues and interproximal embrasures are not
covered free flow of saliva is present and marginal gingiva
recieves natural stimulation

disadvantages
1. Tendency to trap debris
2. In Crowding cases adaptability becomes difficult
3. Irritation to tongue

Labial bar
 Lingually inclined teeth
 Mandibular tori
 Difficult for patient to adjust

Disadvantages of labial barDisadvantages of labial bar
1.1. Patients acceptance is generally poorPatients acceptance is generally poor
2.2. Bulk distorts the lower lipBulk distorts the lower lip
3.3. Esthetically unpleasingEsthetically unpleasing

Swing lock
Dr Joe J simmons in 1963
Has a hinge device at one end & locking device in the other.
This allows it to be positioned more intimately against
Gingival tissue.

Minor connectors

Definition
Minor connectors can be defined as the connecting link
between the major connector or base of a removable partial
denture to other units of a prosthesis such as clasp
assembly,indirect retainers,rests etc

FUNCTIONS OF A MINOR
CONNECTOR
1. It connects the major connector to other parts like
clasps, rests, indirect retainers and denture bases
2. To transfer functional stress evenly to edentulous ridge
and remaining teeth

Basic principles of design of a minor
connector
1. Should have sufficient bulk to be rigid
2. When contacting an axial surface it should not be
located on a convex surface but instead should be
located in an embrasure where it will be least
noticeable to the tongue.

Types of minor connectors
1. Join clasp assembly to the major connector.
2. Join indirect retainers and auxilary rests to major connector.
3. Join denture base to the major connector
4. Serve as an approach arm for a vertical projection or bar type
of clasp

1.Minor connectors joining clasp assembly to major connector

 When an artificial tooth is to be placed the thickest portion
should be at the lingual line angle of the abutment tooth.This
way bulk is ensured with least interference to the placement
of the artificial tooth.

2. Minor connectors that join indirect retainers or auxiliary
rests to major connector
1. Should form a right angle with the major connector
2. Should lie in embrasure between teeth to disguise its bulk as
much as possible.

Minor connectors that join the denture base to
the major connector
3 types:
1. Lattice work construction
2. Mesh construction
3. Bead,wire or nail head minor connector

1.Open latticework construction

Advantages
1. Provides the strongest attachment of the acrylic
resin denture base to the removable partial
denture.
2. Easiest to reline if necessary

2.Mesh construction

disadvantagesdisadvantages
1. Main drawback is that it is more difficult to pack acrylic
resin dough because more pressure is needed against the
resin to force it through the small holes.
2. It also does not provide as strong an attachment for the
acrylic denture base as compared to the lattice framework

Tissue stops
Used on all distal extension partial dentures using latticework or
mesh retention.
2x2 mm

Bead ,wire or nail head retention minor
connector
Used with a metal denture base which is cast to fit directly against
the edentulous ridge.

1. Indicated when inter arch space is limited and acrylic
resin by itself would not have sufficient strength to
withstand the forces of occlusion.
2. Retention of the acrylic resin is obtained by projection of
metal on its surface These projections may be in the form
of beads,wires or nail heads.

AdvantagesAdvantages
1.1. Improved hygieneImproved hygiene
2.2. Thermal stimulationThermal stimulation
disadvantagesdisadvantages
1. Cannot be adequately relined in case of ridge
resorption.
2. Weakest attachment.

FINISH LINES
 To provide sufficient bulk of acrylic resin to produce a
smooth and even joint with the metal framework,
provision must be made to provide space for a butt joint so
that the acrylic resin can be finished evenly with the major
connector.
2 types
-Internal finish line
-External finish line

4. Minor connectors that serve as an
approach arm for vertical projection or bar
type of clasp

Review of literatureReview of literature

The effect of design modifications on the torsionalThe effect of design modifications on the torsional
and compressive rigidity of U shaped palatal majorand compressive rigidity of U shaped palatal major
connectors. J prosthet dent 2003;vol 89;page 400connectors. J prosthet dent 2003;vol 89;page 400
1.1. Doubling the thickness of U shaped maxillary majorDoubling the thickness of U shaped maxillary major
connector significantly increased the rigidity ofconnector significantly increased the rigidity of
framework when tested in compression and torsionframework when tested in compression and torsion
2.2. The addition of posterior strap significantly increased theThe addition of posterior strap significantly increased the
rigidity of maxillary major connector with an anteriorrigidity of maxillary major connector with an anterior
strap when tested in compression and torsionstrap when tested in compression and torsion
3.3. U shaped maxillary major connector becomes moreU shaped maxillary major connector becomes more
flexible as the length of the arch is increased. The additionflexible as the length of the arch is increased. The addition
of posterior strap is more effective in countering thisof posterior strap is more effective in countering this
increased flexibility when tested in compression andincreased flexibility when tested in compression and
torsiontorsion

Stiffness of different designs and cross sections ofStiffness of different designs and cross sections of
maxillary and mandibular major connectors ofmaxillary and mandibular major connectors of
removable partial dentures j prosthet dent 1999;removable partial dentures j prosthet dent 1999;
vol81; page 526vol81; page 526
1.1. In the maxillary arch the most rigid major connector wasIn the maxillary arch the most rigid major connector was
anteroposterior palatal bar combination placed onanteroposterior palatal bar combination placed on
different horizantal and vertical planes.different horizantal and vertical planes.
2.2. The most flexible was the u shaped design.The most flexible was the u shaped design.
3.3. In mandibular arch the most important factor inIn mandibular arch the most important factor in
achieving rigidity was the cross-sectional shape of theachieving rigidity was the cross-sectional shape of the
major connectormajor connector
4.4. The half pear shaped cross section proved to be moreThe half pear shaped cross section proved to be more
rigidrigid

CONCLUSIONCONCLUSION
““The importance of each requirement depends onThe importance of each requirement depends on
the type of partially edentulous arch that is being treated.the type of partially edentulous arch that is being treated.
Hence, the type of major or minor connector should beHence, the type of major or minor connector should be
selected on the basis of an individual patient needs”.selected on the basis of an individual patient needs”.

BIBLIOGRAPHYBIBLIOGRAPHY
1. Glossary of Prosthodontic Terms -8 th Edn, 2005.1. Glossary of Prosthodontic Terms -8 th Edn, 2005.
2. Stewart, Rudd, Kuebker : Clinical Removable Partial2. Stewart, Rudd, Kuebker : Clinical Removable Partial
Prosthodontics.Prosthodontics.
3. Removable partial prosthodontics,2nd
edition ,
Ernest L Miller
4. McCracken’s : Removable Partial Prosthodontics -4. McCracken’s : Removable Partial Prosthodontics -
11 edition11 edition
5. J c davenport ; A colour atlas of removable partial dentures.5. J c davenport ; A colour atlas of removable partial dentures.

6. James s brudwik : Advanced removable partial denture6. James s brudwik : Advanced removable partial denture
7. John Osborne : partial dentures, iv edition7. John Osborne : partial dentures, iv edition
8. The effect of design modifications on the torsional and8. The effect of design modifications on the torsional and
compressive rigidity of U shaped palatal major connectors. Jcompressive rigidity of U shaped palatal major connectors. J
prosthet dent 2003;vol 89;page 400prosthet dent 2003;vol 89;page 400
9. Stiffness of different designs and cross sections of maxillary9. Stiffness of different designs and cross sections of maxillary
and mandibular major connectors of removable partialand mandibular major connectors of removable partial
dentures j prosthet dent 1999; vol81; page 526dentures j prosthet dent 1999; vol81; page 526

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Raju major n minor connectors/dental courses

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