mandibularmajorconnectors-220110094500.pptx

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1. MANDIBULAR MAJOR CONNECTORS DEPT. OF PROSTHODONTIC

2. CAST P A R T I A L DENTURE Components of a typical removable partial denture are: Major connectors Minor connectors Rests Direct retainers Indirect retainers Denture base Denture teeth

3. MAJOR CONNECTOR “ the part of a removable partial denture that joins the components on one side of the arch to those on the opposite side.” - Glossary of Prosthodontic Terms- 9

4. FUNCTIONS OS MAJOR CONNECTOR unification of the major parts of the prosthesis distribution of the applied force throughout the arch to selected teeth and tissue minimization of torque to individual teeth cross- arch stabilization

5. REQUIREMENTS OF A MAJOR CONNECTOR Are made from an alloy compatible with oral tissue. Are rigid and provide cross- arch stability through the principle of broad distribution of stress. Do not interfere with and are not irritating to the tongue. Do not substantially alter the natural contour of the lingual surface of the mandibular alveolar ridge or of the palatal vault. Do not impinge on oral tissue when the restoration is placed, is removed, or rotates in function. Cover no more tissue than is absolutely necessary. Do not contribute to retention or trapping of food particles. Have support from other elements of the framework to minimize rotation tendencies in function. Contribute to the support of the prosthesis

6. MANDIBULAR MAJOR CONNECTORS Lingual bar Linguo- plate Double lingual bar Labial bar

7. LINGUAL BAR

8. 1. LINGUAL BAR Most commonly used Shape: 🢝 flat on tissue side 🢝 convex or tear- drop on tongue side (1/2 pear shape, with thin edge toward teeth) Size: 🢝 occluso- gingival width = 4 to 6 mm. 🢝 thickness = l.5 to 2 mm.

9. 1. LINGUAL BAR Lingual bar major connector should be located at least 4 mm inferior to gingival margins and farther if possible. The vertical height of a finished lingual bar should be at least 4 mm for strength and rigidity. If less than 8 mm exists between gingival margins and the movable floor of the mouth, linguoplate may be used.

10. 1. LINGUAL BAR Simple to fabricate. Indicated for all tooth-supported removable partial dentures unless there is insufficient space between the marginal gingivae and the floor of the mouth. Minimal tooth contact = less plaque accumulation. If not designed properly, the framework may become too weak and flexible.

11. SUB- LINGUAL BAR A modification of the lingual bar where in the placement is inferior and posterior to the usual placement of a lingual bar, lying over and parallel to the anterior floor of the mouth. It can be substituted for lingual plate if the lingual frenum does not interfere, or in the presence of an anterior lingual undercut that would require considerable blockout for a conventional lingual bar. Contraindications: interfering lingual tori high attachment of a lingual frenum interference with elevation of the floor of the mouth during functional movements.

12. LINGUO- PLATE

13. 2. LINGUO- PLATE The lingual plate consists of a lingual bar plus an extension over the cingula of anterior teeth. A linguoplate should be made as thin as is technically feasible and should be contoured to follow the contours of the teeth and the embrasures. Shape: 🢝 convex or tear- drop on tongue side (1/2 pear shape, with thin edge toward teeth).

14. 2. LINGUO- PLATE Indications: When the lingual frenum is high or the space available for a lingual bar is limited. (Available sulcus depth <8 mm) In Class I situations in which the residual ridges have undergone excessive vertical resorption. (Reduces horizontal rotations) For stabilizing periodontally weakened teeth. (Splinting) When the future replacement of one or more incisor teeth will be facilitated by the addition of retention loops to an existing linguoplate.

15. INTERRUPTED LINGUO- PLATE Interrupted linguoplate in the presence of interproximal spaces.

16. DOUBLE LINGUAL BAR

17. 3. DOUBLE LINGUAL BAR (KENNEDY BAR) A double lingual bar = lingual bar + lingual plate major connectors. INDICATIONS: A double lingual bar is indicated primarily when contact with the remaining mandibular anterior teeth is indicated, but open embrasures exist.

18. 3. DOUBLE LINGUAL BAR (KENNEDY BAR) SHAPE: The lower component of this major connector should be half- pear shaped in cross section, with its greatest diameter at the inferior margin. The upper bar should be half oval in cross section. This bar should be 2 to 3 mm in height and 1 mm thick. It should present a scalloped appearance. The two bars should be joined by rigid minor connectors at each end.

19. 3. DOUBLE LINGUAL BAR (KENNEDY BAR) ADVANTAGES: Indirect retention and horizontal stabilization. Because the gingival tissues and the interproximal embrasures are not covered, a free flow of saliva is permitted and the marginal gingiva receives natural stimulation. DISADVANTAGES: Accumulation of debris. Discomfort to tongue.

20. CINGULUM BAR A cingulum bar located on or slightly above the cingula of the anterior teeth may be added to the lingual bar or can be used independently. In addition, when wide diastemata exist between the lower anterior teeth, a continuous bar retainer may be more esthetically acceptable than a linguo- plate.

21. LABIAL BAR

22. 4. LABIAL BAR INDICATIONS: Extreme lingual inclination of the remaining lower premolar and incisor teeth prevent the use of a lingual bar major connector. When a mandibular torus interferes with placement of a lingual bar. Use of a labial bar connector should be avoided.

23. SWING LOCK DESIGN

24. SWING LOCK DESIGN Linguoplate + labial bar + hinge. Support is provided by multiple rests on the remaining natural teeth. Stabilization and reciprocation are provided by a linguoplate that contacts the remaining teeth and are supplemented by the labial bar with its retentive struts. Retention is provided by a bar type of retentive clasp with arms projecting from the labial or buccal bar and contacting the infrabulge areas on the labial surfaces of the teeth.

25. SWING LOCK DESIGN INDICATIONS: Missing key abutments Unfavorable tooth contours Unfavorable soft tissue contours Teeth with questionable prognoses CONTRAINDICATIONS: Poor oral hygiene or lack of motivation for plaque control by the patient. Presence of a shallow buccal or labial vestibule or a high frenal attachment.

26. SUMMARY

27. EXAM ORIENTED QUESTIONS

28. EXAM ORIENTED QUESTIONS LAQ: Define major connectors. Classify maxillary/ mandibular major connectors and describe them in detail with diagrams. SAQ: Requirements and functions of major connectors. Lingual bar major connector Lingual plate major connector Swing lock major connector Factors determining choice of mandibular major connectors

29. REFERENCES

30. THANK YOU