SIUST, College of Dentistry Removable Prosthodontics II, Lec.6

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Components of Metal

Removable Partial Denture

Basically, RPDs composed of:

1. Major connector.

2. Minor connectors.

3. Rests.

4. Direct retainers.

5. Stabilizing or reciprocal components (as of a clasp assembly).

6. Indirect retainers (if the prosthesis has distal extension bases,

i.e. free-end saddles).

7. One or more bases, each supporting one to several teeth.

In general, when using a prosthesis that can be removed from the

mouth, i.e. R.P.D., the prosthesis must extend to both sides of the

arch. This enables direction of functional forces to supporting teeth

and tissue for optimum stability.

SIUST, College of Dentistry Removable Prosthodontics II, Lec.6

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The Major Connectors

  It is that part or unit of a R.P.D. which joins the parts located on

one side of the arch to those on the opposite sides. It is that

unit to which all other parts of a R.P.D. are directly or indirectly

attached.

Those major connectors are either bars or plates, they differ

according to the amount of covered tissues, where plates are broad

and thin and bars are thick and bulky.

The major connector helps in the support of the prosthesis.

SIUST, College of Dentistry Removable Prosthodontics II, Lec.6

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Where should the major connector be located?

Generally, major connector should be designed and located with

following guidelines in mind:

1. Should be a way from movable tissues.

2. Impingement of gingival tissue should be avoided.

3. Bony and soft tissue prominences should be avoided during

placement and removal.

4. The maxillary major connector should be (6-8) mm away from

gingival margin.

5. The mandibular major connector should be (3-4) mm away from

the gingival margin.

SIUST, College of Dentistry Removable Prosthodontics II, Lec.6

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Characteristics of Major Connector:

1. Rigidity, strength and free from sharp margins.

2. Does not interfere with tongue.

3. Does not alter the natural contour of the lingual surface of the

mandibular alveolar ridge, or the palatal vault.

4. Does not impinge on the oral tissues at insertion and removal

from the mouth or during function.

5. Does not cause food stagnating or trapped.

6. Covers the minimum necessary amount of tissue.

7. Aids in support of the prosthesis.

8. The design of the major connector should be made so as to

avoid any soft tissues or bony prominence during insertion or

removal.

Beading of Maxillary Cast

Beading is the scribing of a shallow groove on the maxillary master

cast outlining the maxillary palatal major connector exclusive of the

rugae area, thus insuring intimate tissue contact of major connector

with the palatal tissues, avoiding food from passing beneath the

maxillary major connector.

Framework design on master cast

before preparation for duplication in

refractory investment. Shallow groove

(0.5 mm) has been scribed on outline of

anterior & posterior borders of the

major connector. Anterior outline

follows valleys of rugae.

SIUST, College of Dentistry Removable Prosthodontics II, Lec.6

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Types of Major Connectors for Maxillary Arch:

1. Single posterior palatal bar or plate.

2. Single anterior palatal bar, Or

maxillary lingual plate.

3. Double palatal bar.

4. Palatal plate or strap.

5. Full palatal coverage.

Types of Major Connectors for Mandibular Arch:

1. Lingual bar.

2. Lingual plate or blanket (linguoplate).

3. Double bar (Kennedy bar).

4. Cingulum bar.

5. Mandibular labial bar.

By

Noor Al-Deen M. Al-Khanati