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Major Connectors

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    Major Connectors

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    Functions of a Major Connector

    Unification

    Partial denture acts as one unit

    Connects various parts

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    Functions of a Major Connector

    Stress Distribution

    Distributes functional loads to both

    teeth & mucosa

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    Functions of a Major Connector

    Cross-Arch Stabilization

    (Counterleverage)

    Bracing elements on one side of thearch providing stability to the other

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    Requirements of a Major Connector

    Rigidity

    Functions as one unit

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    To Increase Rigidity

    Use a more rigid alloy

    Chrome-cobalt > gold alloys; cast > wrought

    Shape

    1/2 round > 1/2 pear shaped > flat bars

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    To Increase Rigidity

    Increase the bulk as the length increases

    Corrugate linguo-plate or rugae areas

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    Requirements

    Non-Interference with Tissues

    Should not enter undercut areas

    avoid by changing path of insertion

    or by using blockout

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    Non-Interference With Tissues

    Avoid terminating on:

    Free gingival margin

    Cross abruptly at 90o

    Relief is used to minimize

    impingement

    (Fig 2-17, Stewart's)

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    Non-Interference With Tissues

    Avoid terminating on:

    Hard structures such as the mid-

    palatal suture or mandibular tori

    Place relief

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    Non-Interference With Tissues

    Avoid terminating on: Lingual frenum & the movable soft palate

    Soft tissue movements must also be allowed

    Careful intraoral exam

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    Minimize Food Impaction

    Locate margins away from the FGM

    Eliminate "traps" or large concavities

    where food can collect

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    Unobtrusive

    Smooth transition from connector to

    denture base - butt joint

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    Unobtrusive

    Line angles and edges should be smooth

    and rounded

    Borders should not interfere with speech

    (Fig 2-21, Stewart's)

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    Mandibular Major Connectors

    Lingual Bar

    Lingual Plate

    Continuous Bar

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    Mandibular Major Connectors

    Lingual Bar

    Most common in mandibe

    Use whenever possible

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    Mandibular Major Connectors

    Lingual Bar

    Shape

    Flat on tissue side

    Convex or tear-drop on

    tongue side

    (1/2 pear shape, with

    thin edge toward teeth)

    (Fig 2-35, Stewart's)

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    Mandibular Major Connectors

    Lingual Bar

    Size

    Occluso-gingival width = 4 to 6 mm

    Thickness = l.5 to 2 mm

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    Inferior Border Mandible

    Patient lifts tongue

    Activates floor of mouth

    Measure from tip of probe to free

    gingival margin

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    Inferior Border Mandible

    Record values in chart, transfer to cast

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    Lingual Bar Position

    Superior border

    l.5-2.0 mm or more below FGM

    As far from gingival margin aspossible

    (Fig 2-15, Stewart's)

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    Potential Impingement

    Anterior major connector moves toward tissueas the posterior portion is loaded

    Space needed more when ridge is less vertical

    (Fig 2-33, Stewart's)

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    Mandibular Major Connector Relief

    Eliminates impingement Wax spacer (relief) placed under major

    connector

    one thickness of 30 gauge wax

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    Lingual Plate (Linguoplate)

    Lingual bar with extension over cingula ofanterior teeth

    Use where a lingual bar cannot be used

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    Lingual Plate Indications

    Potential Impingement from lingual bar

    High floor of the mouth

    Prominent lingual frenum

    Lingual tori

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    Lingual Plate

    Rest at each end of lingual plate

    Prevents forces being directed facially

    Easier denture tooth addition than bar

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    Lingual Plate Variations

    May show through embrasures

    (Fig 2-41 & 43, Stewart's)

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    Continuous Bar Retainer(Kennedy Bar, Double Lingual Bar)

    Lingual bar with secondary bar above

    cingula

    Secondary bar acts as indirect retainer

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    Continuous Bar Retainer

    Potential food trap between two bars

    Normally avoid

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    Maxillary Major Connectors

    Anterior-Posterior Palatal Strap

    Full Palatal Strap

    Palatal Strap

    Anterior Palatal Strap

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    Maxillary Major Connectors

    Terminate 4.0 mm or more from free

    gingival margin when possible

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    Anterior-Posterior Palatal Strap

    Maximum rigidity

    Minimum bulk

    Use in most cases

    Especially torus palatinus

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    Anterior-Posterior Palatal Bar

    A narrow (A-P) variation of anterior-

    posterior palatal strap

    Double palatal bar connector

    Requires greater bulk for rigidity

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    Anterior-Posterior Palatal Bar

    More objectionable to the patient

    Strap connectors provide greater

    distribution of stresses

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    Full Palatal Plate

    Maximum tissue support

    Connector of choice in long distal

    extension cases

    Six or less anterior teeth remain

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    Full Palatal Plate

    Abutments are periodontally involved

    Maximum stress distribution

    Flabby tissue

    Shallow palatal vault

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    Full Palatal Plate

    Greater stability and stress distribution

    Not used with torus

    Increases retention

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    Full Palatal Plate

    Connector should:

    Be fabricated of uniformly thin metal

    Have accurate anatomic reproduction

    of the ruggae

    improves strength and rigidity

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    Full Palatal Plate

    Connector should:

    Cover same area as complete denture

    posteriorly

    Have large surface area of mucosal contact

    improves potential for retention

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    Full Palatal Plate

    Generally of cast metal

    Acrylic resin used in interim prostheses

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    Palatal Strap

    Usually use for Class III & IV cases

    Wide anterio-posteriorly

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    Palatal Bar Dont use

    Narrow anterio-posteriorly

    Thick occluso-gingivally

    Palatal bar objectionable due to bulk

    (Fig 2-24, Stewart's)

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    Palatal Strap (or Bar)

    Neveruse in cases involving distal extensions orreplacement of anterior teeth since it must be

    made bulky for rigidity

    Relief may be required over bony midline

    Not used with torus

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    Anterior Palatal Plate(U-Shaped or "Horse-Shoe" Palatal Connector)

    Poor connector

    Neveruse unlessabsolutely necessary

    Requires bulk in the

    rugae area (where

    the tongue requires

    freedom) for rigidity

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    Anterior Palatal Plate

    Too flexible

    Allows movement at the posterior Traumatic to the residual ridge

    Use only where torus prohibits other

    connectors

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    Flexes, impinging on soft tissue

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    Unilateral RPD

    Dangerous

    Avoidaspiration

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