Week 2 - Components of RPD Flashcards
(44 cards)
What is the function of a major connect
- unification of the major parts of the prothesis
- distribution of the applied force throughout the arch
- minimization of torque to the teeth
- restricting movement (cross arch stability)
where should a major connector be located
- away from moveable tissue
- no impingement on gingival tissue or oral mucosa
- clear from bony and soft tissue prominences during placement and removal
what angle do minor connects join the major connect at
right angle
What are types of mandibular major connectors
- lingual bar
- linguoplate
- sub lingual bar
- lingual bar with cingulum bar
- cingulum bar (continuous bar
- labial bar
lingual bar
- basic form of major connector, pear shape, tapered superior border with 4mm width
- should be 7mm space between gingival margin and floor of the mouth
- runs along the lingual side of the lower teeth, positioned just above the floor of the mouth
- its the most common choice due to its simplicity and patient comfort
What is the depth of a lingual bar
4mm
What is a sublingual bar
- variation of the lingual bar
- placed lower and closer to the floor of the mouth often extending slightly under the tongue in comparison tot he lingual bar
- it’s used when there’s limited vertical space (less than 8mm) due to high floor of the mouth or tori
- offers stability without compromising tongue space
linguoplate
- plate bordered by a lingual bar, minor connectors, anterior teeth contact and cingula
- mandibular major connector
*cannot serve as an indirect retainer
superiorly where should a linguoplate be located
should not be located above the middle 1/3 of lingual surface and should follow the curvature of the tooth surface
can a linguoplate serve as a indirect retainer
no,
because it is a major connector, not a retentive element. It rests on unprepared lingual surfaces and provides indirect retention and stability, but it lacks the specific designs (like clasps) needed to actively engage undercuts on teeth for direct retention
why use a linguoplate
- lack of space or high lingual frenum
- in case of flat ridge (by splinting the remaining teeth to help resist horizontal movements)
- for stabilising teeth with mobility
- when future replacement of anterior teeth is expected
What are disadvantages of a linguoplate
- impairs periodontal health (the least favorable MC)
- maximizes the tissue coverage
- poor aesthetic if the teeth are spaced
What are the types of maxillary major connectors
- single palatal strap
- anterior posterior palatal strap
- palatal plate
- U-shape
- single palatal bar
- Anterior posterior palatal bar
single palatal strap
- maxillary major connector
advantages of a single palatal strap
- suitable rigidity without excessive bulk can be achieved
when is a single palatal strap used
bilateral tooth supported prothesis
Specific for class 3 edentulous ridge
disadvantages of single palatal strap
distal extensions ridges (due to the excessive bulk required to achieve enough rigidity) thus not ideal for free-end saddles
anterior- posterior palatal straps/bars
- maxillary major connector
- specific for class 2 and 4
Requirements for anterior-posterior palatal straps/bars
- posterior palatal strap more than or equal to 8mm
- located as far posteriorly as possible, but anterior to vibrating line
- all straps/bars should cross the midline at right angles
- anterior strap can be extended to restore anterior edentulous area
U-shaped palatal connectors
- maxillary major connector
- lest desirable major connector
when use a u shaped palatal connector
inoperable large palatal torus and rarely to replace several anterior teeth
disadvantages of a U shape palatal connectors
- lack of rigidity (damage to soft tissue and teeth)
- uncomfortable for patient and poor vertical support
- edges may cause tissue irritating
- shape can trap food particles
- poor vertical support
What is a direct retainer
A components (like a clasp) that engages a specific tooth to resist dislodgement of the denture in an occlusal direction (away from the tissues)
It provides primary retention by physically gripping an abutment tooth, preventing the denture from lifting off.
What is a indirect retainer
A component (often a rest or connector) positioned on a tooth away from the denture’s fulcrum line to resist rotational forces or tiliting
It doesn’t directly hold the denture in place but stabilizes it by counteracting leverage, especially when sticky foods or forces lift the denture base
