This presentation specifically deals with the maxillary and mandibular Major connectors used in a cast partial denture. it also mentions the uses, advantages and disadvantages of each,
2. Contents
Introduction
Major connectors
Role of major connectors
Types of maxillary major connectors
Review of indications
Steps in Designing
Types of Mandibular major connectors
Review of indications
Steps in Designing
Recent advances
Conclusion
References
2
3. Introduction
Name of components – descriptive of
function
Components
Major
connectors
Minor
connector
Rests
Direct
retainer
Indirect
retainer
Denture
base
3
4. Contents
Introduction
Major connectors
Role of major connectors
Types of maxillary major connectors
Review of indications
Steps in Designing
Types of Mandibular major connectors
Review of indications
Steps in Designing
Recent advances
Conclusion
References
4
5. Major connectors
A major connector joins the components of
the removable partial denture from one side of
the arch to the opposite side
5
6. Contents
Introduction
Major connectors
Role of major connectors
Types of maxillary major connectors
Review of indications
Steps in Designing
Types of Mandibular major connectors
Review of indications
Steps in Designing
Recent advances
Conclusion
References
6
7. Role of major connectors
Be rigid
Protect the associated soft tissue
Provide means for obtaining indirect
retention
Provide a means of placement of denture
base
Promote patient comfort
Self cleansing
7
8. Rigidity :
Permits broad distribution of
forces
Protect soft tissue:
Maxillary connector – 6mm
from marginal gingiva
Mandibular connector –
3mm from marginal gingiva
8
9. Provide means of
indirect retention:
By use of indirect retainers,
rotation around the fulcrum
line can be prevented
Promote patient
comfort:
Edges should be contoured
9
10. Major connector is based on the
principle of leverage
10
It will limit movement possibilities by acting
as a counter-acting lever
CROSS-ARCH STABILITY
12. Requirements of maxillary major
connectors
Borders – 6mm from gingival margins
Anterior border should blend with the
palatal anatomy
Borders should cross the margins at right
angles
Palatal strap – 8mm wide
Open central connectors – medial borders
should be located at the junction of
horizontal and vertical surfaces
12
13. Thickness of the plate should be uniform
Borders should be gently curved
Intaglio surface should not be highly
polished
13
14. Contents
Introduction
Major connectors
Role of major connectors
Types of maxillary major connectors
Review of indications
Steps in Designing
Types of Mandibular major connectors
Review of indications
Steps in Designing
Recent advances
Conclusion
References
14
15. Types of Maxillary major
connectors
• Palatal bar
• Palatal strap
• Antero-posterior palatal bar
• Horse-shoe shaped
• Antero-posterior palatal
strap
• Complete palate
6 types of
maxillary
major
connectors
15
17. Narrow, half oval
Thickest point at the centre
Gentle curved and should not form an
angle
Indications
class III (short span)
application
17
18. 18
*Palatal bar has few
advantages and
should be avoided
*Bulky – causes
discomfort to the
patient
*Narrow antero-
posterior width
Advantage/Disadvantage
20. Most versatile
Band of metal with a thin cross-sectional
dimension
A-P dimension should not be less than
8mm
20
21. Width should be increased with the length
of the edentulous span
Indication
Kennedy’s class II
21
22. 22
*Increased resistance
to bending and
twisting forces
*can be kept thin
*little interference with
normal tongue action
*increased tissue
coverage
*Excessive palatal
coverage
* Anterior border
should be positioned
posterior to rugae
* Prone to papillary
hyperplasia
Advantage/Disadvantage
27. Consists of a thin band of metal
Lingual surface of remaining teeth to
palatal tissue – 6-8 mm
Should be symmetrical – equal height
on both sides
27
28. Advantage/Disadvantage
*Strong connector
*Derives some
vertical support from
tissues of hard palate
*Designed to avoid
bony prominences
Tendency to deform
Does not provide
cross-arch
stabilisation
Should be considered
only if more rigid
connectors cannot be
used
28
29. Horse shoe major connector has a tendency to
Flex or deform. Hence it is not a good connector
When cross arch stabilization in required.
29
34. Provides ultimate rigidity and support
Maximum tissue coverage
Must be kept 6mm away from
gingival margins
Mechanical seal – presence of bead
line along posterior border
34
35. ADVANTAGES
All posterior teeth to be replaced
Remaining teeth are periodontally
compromised
Provides vertical support
Permits force distribution to the teeth as
well as the tissues
Comfortable
Coverage of multiple planes – L beam
effect 35
36. DISADVANTAGES
Adverse soft tissue reaction may occur
– soft tissue hyperplasia – poor oral
hygiene and prolonged periods of
denture wearing
36
37. Indications
Case Type of major connector
Weak periodontal support Wide palatal strap or complete
palate
Adequate periodontal support Palatal strap or A-P palatal strap
Long-span distal extension A-P palatal strap or complete
palate
Anterior teeth to be replaced A-P palatal strap, complete palate
or horseshoe major connector
Presence of torus A-P palatal strap, A-P palatal bar,
horse shoe connector
37
38. Design of maxillary major
connectors
:
Outline
primary
stress
bearing
areas
Outline
non
bearing
areas
Outline of
connector
areas
Selection
of
connector
type
Unification
38
39. Requirements of mandibular
major connectors
Rigid without being bulky
Must not impinge on the movable
floor of the mouth
Relief required between the rigid
metal connector and underlying
tissues
39
40. Contents
Introduction
Major connectors
Role of major connectors
Types of maxillary major connectors
Review of indications
Steps in Designing
Types of Mandibular major connectors
Review of indications
Steps in Designing
Recent advances
Conclusion
References
40
41. Types of mandibular major
connectors
• Lingual bar
• Lingual plate
• Double lingual
bar
• Labial bar
4 types of
mandibular
major
connectors
41
43. Most frequently used
Cross-section – half pear shaped
Broadest portion near the floor of the
mouth
8mm space between gingival margin
and floor of the mouth
Presence of mandibular tori –
surgical removal
43
44. *Minimal contact with
remaining teeth
*Simple design
*Decreased plaque
accumulation
*Increased soft tissue
stimulation
*If care is not taken,
frame work may not be
rigid
*Too thin or too flexible
– concentration of
potentially destructive
forces on individual
teeth
44
46. Half pear shaped – this solid piece of
metal extending from superior border
to lingual surfaces of teeth
Lingual border as low as possible -
avoid interferences with functional
movements
Plate must completely close the
interproximal surfaces
46
47. Superior border is knife-edged to
avoid “ledging”
Open embrasures or widely spaced
teeth – modification – “step back”
Metal should cross gingival margins
at right angles
To ensure rigidity – inferior border
should be made thicker
“Ledging” occurs when metal
margins are thick or linear
and provides unnatural
contours
“Step back” modification
requires the superior border
of the plate to cover the
cingulum of the individual
tooth
47
48. *Exceptional rigidity – des
not interfere with functional
movements
*Stabilize periodontally
weak teeth
*May provide additional
indirect retention
*If mandibular tori cannot be
removed, adequate relief
should be provided
*Extensive coverage –
decalcification of enamel
*Irritation of tissues in
patients with poor oral
hygiene
48
50. Lingual bar + lingual plate
Upper and lower borders are similar
to lingual plate
No continuous metal sheet
Upper bar – half oval cross-section
(2-3 mm height and 1mm thickness)
Two bars should be connected by
rigid minor connectors
50
51. Rests should be placed at each end
of the bar – no further posterior than
1st premolar
51
52. *Effectively
extends indirect
retention in an
anterior direction
*Free flow of
saliva – marginal
gingiva stimulation
Tendency to trap
debris
Uncomfortable –
multiple borders
and thickness
52
54. Runs across mucosa on facial
surface
Half pear shaped
Longer than lingual bar
Height and thickness must be greater
Successful treatment very limited
54
55. SWING LOCK MODIFICATION
Labial component does not serve as
major connector
Hinge at one end and locking device on
the other
Permits RPD to reach inaccessible
undercuts
55
56. Considered when
remaining major
connectors cannot be
used
*Patient acceptance is
poor-uncomfortable
*Bulk distorts the lower lip
*Labial vestibule not deep
enough to accommodate
a rigid connector without
encroaching on the
gingival margins
56
57. Indications
Tooth supported RPD Lingual bar
Insufficient room between floor of
mouth and gingival margins
Lingual plate
Anterior teeth with reduced
periodontal support
Lingual plate
Anterior teeth with reduced
periodontal support and large
interproximal spaces
Double lingual bar
Replacement of all mandibular
posteriors
Lingual plate
57
58. Design of mandibular major
connectors
I – outline basal seat area on the
diagnostic cast
II – outline inferior border of major
connnector
III – outline superior border of Major
connector
IV – unification
58
60. Contents
Introduction
Major connectors
Role of major connectors
Types of maxillary major connectors
Review of indications
Steps in Designing
Types of Mandibular major connectors
Review of indications
Steps in Designing
Acrylic dentures
Recent advances
Conclusion
References 60
61. Acrylic dentures
Most commonly used
Indicated when the life of the denture
is expected to be less
Or if relining may be necessary
Weaker and less rigid than the metal
alloys - more likely to flex or fracture
during function.
61Connectors -J. C. Davenport, R.M.Basker, J. R. Heath, J. P. Ralph, PO. Glantz,
and P. Hammond (BDJ)
62. INDICATIONS
During the phase or rapid bone
resorption after tooth loss
When remaining teeth have poor
prognosis, and an extraction and
replacement is expected
Interim denture
In growing individuals
62Connectors -J. C. Davenport, R.M.Basker, J. R. Heath, J. P. Ralph, PO. Glantz,
and P. Hammond (BDJ)
63. Design for the replacement of one or two
anterior teeth in young
people is the 'spoon' denture. It reduces
gingival margin coverage to a
minimum, but a potential hazard is the
risk of inhalation or ingestion.
A more stable and therefore more
widely applicable design is the
modified spoon denture. Here one
has the choice of relying on frictional
contact between the connector and
the palatal surfaces of some of the
posterior teeth, or of adding wrought
wire clasps.
63Connectors -J. C. Davenport, R.M.Basker, J. R. Heath, J. P. Ralph, PO. Glantz,
and P. Hammond (BDJ)
64. Another acceptable design is the 'Every'
denture which can be used for
restoring multiple bounded edentulous
areas in the maxillary jaw.
Acrylic RPDs in the mandible often lack tooth-support making
tissue damage highly probable. Such RPDs should therefore
be avoided whenever possible.
64Connectors -J. C. Davenport, R.M.Basker, J. R. Heath, J. P. Ralph, PO. Glantz,
and P. Hammond (BDJ)
65. Contents
Introduction
Major connectors
Role of major connectors
Types of maxillary major connectors
Review of indications
Steps in Designing
Types of Mandibular major connectors
Review of indications
Steps in Designing
Acrylic dentures
Recent advances
Conclusion
References 65
66. Recent advances
Recent work has shown that
CAD/CAM/RP technologies can be
successfully applied to the fabrication
of RPD alloy frameworks
66
70. Bibliography
McCracken’s removable partial prosthodontics –
12th edition
Stewarts removable partial prosthodontics – 4th
edition
Partial dentures – John osborne and George
Lammie – 4th edition
Connectors -J. C. Davenport, R.M.Basker, J. R. Heath, J. P.
Ralph, PO. Glantz, and P. Hammond (BDJ)
Use of CAD/CAM technology to fabricate a
removable partial denture framework (R. J. Williams, BA,
PhD,a Richard Bibb, BSc, PhD,b Dominic Eggbeer, BSc,c and John Collis,
BDS) (JPD)
70