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MINOR CONNECTORS

MINOR CONNECTORS

DR. SILPA ABRAHAMIst MDSDEPT. OF PROSTHODONTICS

definitionThe 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

functionsJoin remaining components of RPD to major connectorTransfers functional stress to abutment teethTransfers the effects of retainers, rests and stabilizes components

-McCrackens Removable Partial Prosthesis

Form And LocationSufficient bulk to be rigidMinor connector which connects axial surface of an abutment should be located in an embrasure rather than on a convex surface

McCrackens Removable Partial Prosthesis

Transfer of functional stresses to the supporting teeth and tissue will not be effective.4

Should conform to interdental embrasure pass vertically from major connector, gingival crossing abrupt

Should be thick towards lingual and tapering towards contact area

McCrackens Removable Partial Prosthesis

Covers as little of gingival tissue as possible.Deepesst portion of embrasure should be blocked out 5

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 coverageEnhanced guidance for insertion and removal stabilization against horizontal and rotational forcesMcCrackens Removable Partial Prosthesis

Disadvantages :encroach tongue space potential space for food entrapment

McCrackens Removable Partial Prosthesis

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

McCrackens Removable Partial Prosthesis

This avoids sharp angles, which could hinder tongue movementand eliminate spaces that dould trap food9

Types of minor connectors

Stewart's Clinical Removable Partial Prosthodontics

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Major Connectors Joining Clasp Assemblies To Major Connectors

Rigid; sufficient bulkSupport restsMostly located on proximal surfaces of teeth adjacent to edentulous areasBroad buccolingually; thin mesiodistally

Stewart's Clinical Removable Partial Prosthodontics

As they connect active components- retentive claspsSupport prevents vertical movement of prosthesis toward underlying tisueResultant shape helps in easier placement of prosthetic tooth in natural position12

If clasp assembly not on adjacent teeth, lingual embrasureUnobtrusiveShould never be kept on convex surface of teethStewart's Clinical Removable Partial Prosthodontics

Minor Connectors Joining Indirect Retainers Or Auxiliary Rests To Major Connectors

Form right angle with major connectorJunctions gently curved Positioned in lingual embrasureStewart's Clinical Removable Partial Prosthodontics

Gently curved;Prevent stress concentration

Lingual embrasure; disguise bulk & promote pt comfort

15

Minor Connectors Joining Denture Bases To Major Connectors

Described as,Open constructionMesh constructionBead, wire or nail head components on a metal baseStrongRigid Minimal interference with arrangement of artificial teethStewart's Clinical Removable Partial Prosthodontics

Strong enough to anchor denture baseRigid enoug to resist fracture and displacement17

Maxillary archDistal extension; extend entire ridge, cover tuberosityShould extend as posterior as possibleStewart's Clinical Removable Partial Prosthodontics

In certain case it extends beyond most prominent portion of tuberosity or terminated anterior to this area18

Mandibular archExtend 2/3 rd of edentulous arch

Stewart's Clinical Removable Partial Prosthodontics

Open ConstructionConsists of longitudinal and transverse struts; ladder like networkStrut placement critical; posterior teeth arrangement This type made using preformed 12guage half round & 18 guage round wax stripsLongitudinal strutsMandibular arch:1 strut buccal to crest of ridge, other strut lingual to crest of ridge

Stewart's Clinical Removable Partial Prosthodontics

Maxillary arch1 strut buccal to ridge crest, Border of major connector 2nd strut

Stewart's Clinical Removable Partial Prosthodontics

Stewart's Clinical Removable Partial Prosthodontics

Transverse struts:Positioned to facilitate placement of artificial teethAdequate room for teeth placementShould pass between necks of artificial teethStewart's Clinical Removable Partial Prosthodontics

Aid in tooth arrangementImprove eshetics 23

Provide relief under gridwork:Adequate mechanical retentionThis space provided by relief wax placed on cast before framework fabricationAbout 1mm relief Relief should begin 1.5-2mm from abutment tooth

Removable Partial Denture Manual, Robert W.Loney

Allows acrylic to flow under gridworkMetal-tissue contact immediately adjacen to toothMetal surface is preferable since it wears less, less porous. Thus hygiene

24

Figure 1Figure 2Figure 3

Junction of this gridwork should be of strong butt type joints, with appreciable bulkAngles formed should not be >90 Removable Partial Denture Manual, Robert W.Loney

Provides maximum blk of acrylic resin denture base at matel junctn, to prevent creation of thin, weak, feather edges which can easily fracture or distort

26

Indication and advantagesWhen multiple teeth are to be replacedProvides strongest attachment of acrylic resin to frameworkFacilitates relining and rebasing of RPDStewart's Clinical Removable Partial Prosthodontics

Mesh ConstructionRigid metallic screenRelief 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

DrawbacksStewart's Clinical Removable Partial Prosthodontics

Cast stopsDistal extension casesRelief -support only at one end bend when load is appliedTo prevent bending, a small area at free end of minor connector should contact master castCAST STOP Stewart's Clinical Removable Partial Prosthodontics

2X2mm wax removed, where posterior strut of minor connector crosses center of the ridgeDepression incoporated in refractory castUpon casting framework and returning it to master cast, cast stp shold contact cast surface

33

Bead, Nail Head Or Wire ConstructionUsed in conjunction with metal denture basesResin attached to free surface of such bases, retention by encompassing surface projectionsNail head same manner.

Stewart's Clinical Removable Partial Prosthodontics

Advantage:Improved hygiene and enhanced thermal stimulationDisadvantage-difficulty in adjusting and relining cast metal basesAttachment of resin is relatively weakStewart's Clinical Removable Partial Prosthodontics

Finish linesThe interface between metal and acrylic is referrred to as finish line.If located outer surface of major connector- external finish lineIf located on inner or tissue surface- internal finish line

Internal Finish LineFormation: relief wax placed on edentulous ridge of master cast prior to duplication24-26 guageCreate elevated area on refractory castMargins of relief wax-establish internal finish linesMargins of wax: sharp and well defined

External Finish LinesSharpShould be slightly undercut to help lock acrylic resin to major connectorInternal angle

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