Presentation on Major Connectors, Minor Connectors, Finish Lines and Metal tissue reactions. Chapter 5 from Mc Cracken Text Book

1. Mc Cracken’s
Removable Partial Prosthodontics
Edition - XII
Seminar Created By
Dr. Joel Koshy Joseph MDS

2. Chapter 5
Major and Minor Connectors

3. Chapter Outline
1. Major Connectors
1. Mandibular Major connectors
2. Maxillary Major Connectors
2. Minor Connectors
3. Finishing Lines
4. Reaction of Tissue to metallic coverage

4. Components of a typical removable partial denture

5. MAJOR CONNECTORS
• That component of the partial denture that connects the parts of the prosthesis
located on one side of the arch with those on the opposite side.

6. • Its that unit of the partial denture to which all other parts are directly or indirectly
attached.
MAJOR CONNECTORS

7. MAJOR CONNECTORS
• This component provides cross arch stability to help resist displacement by
functional stresses.

8. Major connectors are similar to that of a framework of a automobile or building.
HENCE IT HAS TO BE RIGID
If not- It leads to traumatic damage to periodontal support of the abutment teeth,
injury to residual ridges or impingement of underlying tissue.

9. LOCATION OF MAJOR CONNECTORS
• SHOULD BE FREE FROM MOVABLE TISSUES.
• IMPINGEMENT OF GINGIVAL TISSUES TO BE AVOIDED
• BONY AND SOFT TISSUE PROMINENSUS SHOULD BE
AVOIDED DURING PLACEMENT AND REMOVAL.
• RELIEF SHOULD BE PROVIDED BENEATH A MAJOR
CONNECTOR TO PREVENT ITS SETTLING INTO AREAS OF
INTERFERENCE (TORI, MID PALATINE SUTURES)
• IN DISTAL EXTENSION AREAS RELIEF SHOULD BE GIVEN
BECAUSE THE DENTURE ROTATES IN FUNCTION.

10. CHARACTERISTICS OF MAJOR CONNECTORS CONTRIBUTING TO HEALTH
AND WELL BEING
• To be made of alloy compatible with oral tissues.
• Rigid and provide cross arch stability – broad distribution of stress
• Does not interfere with and not irritating to tongue
• Do not alter the natural contour of lingual surface of mandibular alveolar ridge or palatal
vault
• Do not impinge oral tissue with the restoration
• Cover no more tissue than necessary
• Do not contribute to retention or trapping of food
• Have support from other elements of the framework to minimize the rotation tendencies
• Contribute to the support of the prosthesis.

11. MANDIBULAR MAJOR CONNECTORS
LINGUAL BAR
LINGUOPLATE
SUBLINGUAL BAR
LINGUAL BAR WITH CINGULUM BAR
CINGULUM BAR (CONTINUOUS BAR)
LABIAL BAR

12. LINGUAL BAR
• 6 - Gauge wax
• Located above moving tissue but far below
the gingival tissue possible.
• Polished
• Cross section- Half Inverted Pear shape.

13. Indications of Lingual Bar
• Lingual bar should be used for mandibular removable partial dentures when sufficient space (8mm) exists
between the slightly elevated alveolar lingual sulcus and the lingual gingival tissue.
Advantages of Lingual Bar
• Finishing Lines: Butt-type joint(s) with minor connector(s) for retention of denture base
• Minimum tissue coverage.
• Does not cover the teeth, so decalcification is minimized.
Dis-advantages of Lingual Bar
• Flexible if poorly constructed.
• Less rigid than lingual plate.

14. LINGUOPLATE
Linguoplate also act as an indirect retainer.
Indications of Lingual Plate
1. Should be used for mandibular removable partial dentures when in-sufficient space (<8mm) exists between
the slightly elevated alveolar lingual sulcus and the lingual gingival tissue.
2. In cases of high lingual frenum attachments.

15. 3. In Class I situations where residual ridge have undergone
excessive vertical resorption compromising Horizontal
stability.
Presence of lingual plate prevents horizontal movements of
the denture.
4. Stabilizing periodontally weakened teeth by splinting with a
lingual plate.
5. Future replacement of one or more incisor teeth can be done.
Advantages of Lingual Plate
• Horizontal stability.
• Less food entrapment.
• Provision for splinting periodontally weak tooth.
• Indirect retention.
Dis-advantages of Lingual Plate
• Decalcification of teeth

17. SUBLINGUAL BAR
Modification of Lingual Bar.
Indicated when the available space above the superior border is less than 4mm.
Contra- indicated in the presence of lingual tori and high lingual frenal attachment.
Dis-advantage- possible hindrances from tongue and floor of the mouth during functional movements.

18. LINGUAL BAR WITH CINGULUM BAR / DOUBLE LINGUAL BAR
/ KENNEDY’S BAR

19. CINGULUM BAR / CONTINUOS BAR
When the axial alignment of the anterior teeth is such that excess blockout of interproximal undercuts
must be made, a cingulum bar may be considered.
A cingulum bar located on or slightly above the cingula of the anterior teeth may be added to the lingual
bar or can be used independently.

20. LABIAL BAR
• Indicated when extreme lingual inclination of the remaining lower premolar and incisor teeth prevent
the use of lingual bar major connector.
• In the presence of Lingual tori.
• Modification of labial bar : Hinged Continuous labial bar.
Indicated : in cases of missing key abutments.
unfavorable tooth counters or soft tissue contours
teeth with questionable prognoses

21. How to design of Mandibular major connector??
Step 1: Outline the basal seat areas on the diagnostic cast?

22. Step 2: Outline the Inferior border of Mandibular major connector?

23. How to determine the height of the Floor of the mouth?
Measure the distance between the incisal edge to
the floor of the mouth while the tip of the tongue
touching the vermillion border of the upper lip.

24. OR
Take impressions with functionally border molded
lingual border.

25. Step 3: Outline the Superior border of Mandibular major connector?

26. Step 4: Connect the basal seat area to the inferior and superior borders of the major connector,
and add minor connectors to retain the acyrlic resin denture base material.

27. MAXILLARY MAJOR
CONNECTORS
SINGLE PALATAL STRAP
COMBINATION ANTERIOR AND POSTERIOR PALATAL STRAP
PALATAL PLATE- TYPE CONNECTOR
U SHAPED PALATAL CONNECTOR
SINGLE PALATAL BAR
ANTERIOR-POSTERIOR PALATAL BAR

28. SINGLE PALATAL STRAP
• Indicated for Short bilateral edentulous posterior spaces.
• Should be rigid and thin (not interfering with the tongue).
• Because of speech, torque and leverage, they should not be used for replacing anterior
edentulous spaces.

29. COMBINATION OF ANTERIOR POSTERIOR PALATAL STRAP
• Rigid, palatal connector which can be used in almost any maxillary partial denture design.
• Flexure is non existent here.
• Major connectors should always cross midline in right lines and never diagonally.

30. PALATAL PLATE – TYPE CONNECTOR
• Thin, broad, contoured palatal coverage.
• They are readily more acceptable to the tongue and underlying tissue because of its uniform thickness and
thermal conductivity.
• Corrugated palate adds strength to the castings, only electrolytic polishing is necessary.
• Greater retention is achieved here.

31. Complete palate – type connector can be used in one of the three ways
Plate covering 2/3rd of the
palate
Plate terminating at the
junction of hard and soft
palate
Palato linguo plate with
provisions for the attachment
of acrylic (Relining possible,
cheaper)
Indicated when the last abutment tooth is either canine or 1st pre molar in cases of Class I Kennedy’s arch.

32. U SHAPED PALATAL CONNECTOR
Indicated in cases of
• Large inoperable palatal torus.
• When anterior teeth are to be replaced.

33. Least Desirable because
• Its flexible.
• Induces lateral forces to
abutment teeth
• Poor support
• To increase rigidity if thickness
is increased then the design
may lead to hinderance to
tongue

34. SINGLE PALATAL BAR
Indicated:
Short Posterior edentulous
areas
Must be centrally located
between the halves of the
denture.
Disadvantage:
For adequate rigidness,
thickness of the bar has to
be increased, which

35. COMBINATION OF ANTERIOR AND POSTERIOR PALATAL
BAR – TYPE CONNECTORS
Indicated:
Long span posterior edentulous spaces.
Disadvantage:
Bulky
Interfere with tongue function.

36. Design of Maxillary Major Connectors
Step 1: Outline of Primary bearing areas:
The primary bearing areas are those that will be covered by the denture
bases.

37. Step 2: Outline of nonbearing areas: The non bearing areas are the lingual
gingival tissue within 5-6 mm of the remaining teeth, hard areas of the
medial palatal raphe (including tori) and palatal tissue posterior to the
vibrating line.

38. Step 3: Outline of Connector areas. Outline areas that are available to
place components of major connector.

39. Step 4: Select the type of connector bases on
1. Mouth comfort
2. Rigidity
3. Location of denture bases
4. Indirect retention.

40. Beading of Maxillary Cast
Beading means to scribe a shallow groove on the maxillary master cast outlining the palatal major connector
design exclusive of rugae areas.
Purpose:
1. To transfer the design of major connector to the investment cast.
2. To provide a visible finishing line for the casting
3. To ensure intimate tissue contact of the major connector with the palatal tissue.

41. A cleoid carver is used to create a groove no larger than
0.5mm in width and depth

42. MINOR CONNECTORS
Those components that serve as the connecting link between the major connector or the
base of removable partial denture and the other components of the prosthesis ( Clasp,
indirect retainers, occlusal rests, cingulum rests. etc).

43. Functions of Minor Connectors
1. Transfers functional stress to the
abutment teeth: Occlusal forces
applied to the artificial teeth are
transferred to the abutment teeth
through occlusal rests.
2. Transfers the effects of the retainers,
rests and stabilizing components
throughout the prosthesis:
the stabilizing component on one
side of the arch may be placed to resist
horizontal forces that originate on the
opposite side.

44. Form and Location of Minor Connectors
• Rigid
• Bulk of the minor connector should
be objectionable.
• Minor connector contacts the axial
surface of abutment should not be
located on a convex surface instead
located in an embrasure.
• Thickest toward the lingual surface
and tapering toward the contact
area.

45. • Form of minor connector
supporting denture bases should be
completely embedded within the
acrylic resin.
• Ladder like pattern should also be
placed in between the tooth.
• Butt joint is requi-
red.

46. Tissue Stops
• Tissue stops are integral parts of minor
connectors designed for retention of acrylic
resin bases.
• They provide stability to the framework during
the stages of transfer and processing.
• Engage buccal and lingual slopes of the
residual ridge for stability.

48. Finishing Index Tissue Stops
Located distal to the terminal abutment and is a continuation of minor
connector contacting the guiding plane.
Its purpose is to establish a definitive finishing index tissue stop for acrylic
resin base after processing.

49. Finishing lines
• The junction between the major
connector and minor connector
should form an angle not greater
than 90 degrees.
• The line should not to placed too
medially, altering the natural contour
of the palate.
• Also the line should not be placed
too far buccally, as it would be
difficult to create a natural contour of
the acrylic resin on the lingual
surface of the artificial teeth.

50. Reaction of tissue to metallic coverage
• Tissue reactions can result from pressure caused by lack of support, lack of adequate
hygiene measures and prolonged contact through continual use of a prosthesis.
• Regions which are incapable of supporting the prosthesis are not relieved adequately.
Eg. Gingival region, mid palatine raphe, incisive papilla. Etc.
• Failure of rest design because of improper design, caries involvement or fracture of
the rest itself or intrusion of abutment teeth under loading.
• Setting of the dentb caused by loss of tissue support.
• Lack of adequate hygiene measures.
• Longer duration of prosthesis usage. Mucous membranes cannot tolerate the constant
contact with a prosthesis without inflammations and breakdown of the epithelial
barrier.

51. References
1. Mc Cracken Removable Partial Prosthodontics Edition 13.
2. Picture Source: Google Search Engine.