Minor connectors

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


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


Disadvantages : encroach tongue space ↑ potential space for food entrapment


When minor connector contacts tooth surfaces on either side of the embrasure, it should taper to the teeth.


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


If clasp assembly not on adjacent teeth, lingual embrasure

Unobtrusive Should never be kept on convex surface of teeth


Minor Connectors Joining Indirect Retainers Or Auxiliary Rests To Major Connectors

Form right angle with major connector Junctions gently curved Positioned in lingual embrasure


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


Maxillary arch Distal extension; extend entire ridge, cover tuberosity Should extend as posterior as possible


Mandibular arch Extend 2/3 rd of edentulous arch


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


Positioning of longitudinal strut along crest

Interferes with placement of artificial teeth

Predisposes denture base to fracture


Transverse struts: Positioned to facilitate placement of artificial

teeth Adequate room for teeth placement Should pass between necks of artificial teeth


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


Mesh Construction Rigid metallic screen Relief and border extension similar to open

construction


Channels pass through connector ↓ permits acrylic resin penetration ↓ resin encirclement ↓ mechanical retention of denture base


Drawbacks

Difficulty during packing of acrylic resin

Interference with arrangement of prosthetic teeth

When restorative space minimal, compromised esthetics


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


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.


Advantage: Improved hygiene and enhanced thermal stimulation

Disadvantage- difficulty in adjusting and relining cast metal bases Attachment of resin is relatively weak


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.

Minor connectors

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