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MINOR CONNECTORSDR. SILPA ABRAHAMIst MDSDEPT. OF PROSTHODONTICS
DEFINITION The connecting link between the major connector
or base of a partial removable dental prosthesis and the other units of the prosthesis, such as the clasp assembly, indirect retainers, occlusal rests, or cingulum rests.
-GPT 8
FUNCTIONS Join remaining components of RPD to major
connector Transfers functional stress to abutment teeth Transfers the effects of retainers, rests and
stabilizes components
-McCracken’s Removable Partial Prosthesis
FORM AND LOCATION Sufficient bulk to be rigid Minor connector which connects axial surface of
an abutment should be located in an embrasure rather than on a convex surface
McCracken’s Removable Partial Prosthesis
Should conform to interdental embrasure pass vertically from major connector, gingival
crossing abrupt
Should be thick towards lingual and tapering towards contact area
McCracken’s Removable Partial Prosthesis
Evidence suggests that gingival attachment loss is more probable on the proximal aspect, thus minor connectors located in embrasures cover susceptible sites.
- A variation in minor connector design for partial dentures, Radford DR Waltor JD.Int J Prosthodontics 1993 Jan-Feb;6(1):50-4.
A modification was proposed limited to maxilla. Minor connector located on lingual surface of
maxillary abutment tooth.Advantages: ↓ gingival tissue coverage Enhanced guidance for insertion and removal ↑ stabilization against horizontal and rotational
forces
McCracken’s Removable Partial Prosthesis
Disadvantages : encroach tongue space ↑ potential space for food entrapment
McCracken’s Removable Partial Prosthesis
When minor connector contacts tooth surfaces on either side of the embrasure, it should taper to the teeth.
McCracken’s Removable Partial Prosthesis
TYPES OF MINOR CONNECTORS
Stewart's Clinical Removable Partial Prosthodontics
Major Connectors Joining Clasp Assemblies To Major Connectors
Rigid; sufficient bulk Support rests Mostly located on proximal surfaces of teeth
adjacent to edentulous areas Broad buccolingually; thin mesiodistally
Stewart's Clinical Removable Partial Prosthodontics
If clasp assembly not on adjacent teeth, lingual embrasure
Unobtrusive Should never be kept on convex surface of teeth
Stewart's Clinical Removable Partial Prosthodontics
Minor Connectors Joining Indirect Retainers Or Auxiliary Rests To Major Connectors
Form right angle with major connector Junctions gently curved Positioned in lingual embrasure
Stewart's Clinical Removable Partial Prosthodontics
Minor Connectors Joining Denture Bases To Major Connectors
Described as, Open construction Mesh construction Bead, wire or nail head components on a metal base
Strong Rigid Minimal interference with arrangement of
artificial teeth
Stewart's Clinical Removable Partial Prosthodontics
Maxillary arch Distal extension; extend entire ridge, cover tuberosity Should extend as posterior as possible
Stewart's Clinical Removable Partial Prosthodontics
Mandibular arch Extend 2/3 rd of edentulous arch
Stewart's Clinical Removable Partial Prosthodontics
Open Construction Consists of longitudinal and transverse
struts; ladder like network Strut placement critical; posterior teeth
arrangement This type made using preformed 12guage
half round & 18 guage round wax strips Longitudinal struts
Mandibular arch: 1 strut buccal to crest of ridge, other strut lingual to
crest of ridgeStewart's Clinical Removable Partial Prosthodontics
Maxillary arch 1 strut buccal to ridge crest, Border of major connector 2nd strut
Stewart's Clinical Removable Partial Prosthodontics
Positioning of longitudinal strut along crest
Interferes with placement of artificial teeth
Predisposes denture base to fracture
Stewart's Clinical Removable Partial Prosthodontics
Transverse struts: Positioned to facilitate placement of artificial
teeth Adequate room for teeth placement Should pass between necks of artificial teeth
Stewart's Clinical Removable Partial Prosthodontics
Provide relief under gridwork:Adequate mechanical retention
This space provided by relief wax placed on cast before framework fabrication
About 1mm relief Relief should begin 1.5-2mm from abutment
tooth
Removable Partial Denture Manual, Robert W.Loney
Figure 1 Figure 2
Figure 3
Junction of this gridwork should be of strong butt type joints, with appreciable bulk
Angles formed should not be >90̊
Removable Partial Denture Manual, Robert W.Loney
INDICATION AND ADVANTAGES
When multiple teeth are to be replaced Provides strongest attachment of acrylic resin to
framework Facilitates relining and rebasing of RPD
Stewart's Clinical Removable Partial Prosthodontics
Mesh Construction Rigid metallic screen Relief and border extension similar to open
construction
Stewart's Clinical Removable Partial Prosthodontics
Channels pass through connector ↓ permits acrylic resin penetration ↓ resin encirclement ↓ mechanical retention of denture base
Stewart's Clinical Removable Partial Prosthodontics
Drawbacks
Difficulty during packing of acrylic resin
Interference with arrangement of prosthetic teeth
When restorative space minimal, compromised esthetics
Stewart's Clinical Removable Partial Prosthodontics
CAST STOPS
Distal extension cases Relief -support only at one end ↓ bend when load is applied To prevent bending, a small area at free end of
minor connector should contact master cast→CAST STOP
Stewart's Clinical Removable Partial Prosthodontics
Bead, Nail Head Or Wire Construction
Used in conjunction with metal denture bases Resin attached to free surface of such bases,
retention by encompassing surface projections Nail head same manner.
Stewart's Clinical Removable Partial Prosthodontics
Advantage: Improved hygiene and enhanced thermal stimulation
Disadvantage- difficulty in adjusting and relining cast metal bases Attachment of resin is relatively weak
Stewart's Clinical Removable Partial Prosthodontics
FINISH LINES
The interface between metal and acrylic is referrred to as finish line.
If located outer surface of major connector- external finish line
If located on inner or tissue surface- internal finish line
Internal Finish Line
Formation: relief wax placed on edentulous ridge of master cast prior to duplication
24-26 guage Create elevated area on refractory cast Margins of relief wax-establish internal finish
lines Margins of wax: sharp and well defined
External Finish Lines Sharp Should be slightly undercut to help lock acrylic
resin to major connector Internal angle<90 Formation: placement of carving of wax during
fabrication
Originate at lingual extent of rest seat Continue down lingual aspect of minor
connector occlusal perspective: Occlusal perspective: external lingual sueface
MINOR CONNECTORS IN SERVE AS APPROACH ARM FOR VERTICAL PROJECTION/BAR-TYPE CLASPS
Neednot be rigid Support direct retainers Approaches from apical direction Approach arm should display smooth, even, taper
from origin to terminus.
REFERENCES
Stewart’s removable partial prosthodontics McCracken’s Removable partial Prosthodintics Robert W Loney, removable partial denture
manual A variation in minor connector design for partial
dentures, Radford DR Waltor JD.Int J Prosthodontics 1993 Jan-Feb;6(1):50-4.