RPD design - connectors Flashcards
what is a connector
- a term used to describe the rigid part of a partial denture that unites other components
- there are minor and major
what is a minor connector
- joins points of other components
what is a major connector
- provides rigidity and stableness
what does a minor connector do
- join components such as rests to a major connector
- transfer functional stresses to an abutment tooth
what should a minor connector be
- rigid
- finish above the survey line on teeth
- cross gingival margin at right angles
- keep area self cleaning
- cover as little gingival tissue as possible
why must the minor connector cross the gingival margin at right angles
- maintain gingival health
- if it had acute angles these would create little spaces called windows that can irritate the gingiva
what should you avoid in minor connectors
- mupltiple ‘Windows’
- these are food ad plaque traps
what should a major connector do
- connects components on one side of the arch to components on the other side
what should major connectors be
- rigid
- avoid covering the gingival margins
- be comfortable, as few edges as possible
- cover as little tissue as is consistent with rigidity
what modifications can be made for major connectors
- base distribution
- need for tissue support
- need for indirect retention
- anatomical limitations
- prognosis of dentition = planning on giving a denture but some of the teeth you know will not last long so design denture so that it can easily add on more teeth
- previous denture influence = patient is valuable resource on denture design = if they’re happy reproduce what they already had
what can a major connector be
either a plate or a bar
what is a plate connector like
- thinner
- covers wider area as not as thick
- option for Craddock class 2 designs
- cross sectional thickness can be as little as 0.5mm
- plate designs may cover gingival margin so are only recommended in mandibular is there is no space for a bar
- to maintain rigidity, depending on coverage and shape of mucosa areas, plate may require to be thicker in cross section
- general rule = less tooth support= more mucosa support
what are bar connectors like
- advantage of less mucosal coverage
- must be made suitably thick in cross section to maintain rigidity = bulky
- common choice for Craddock class 1
- as there is less space in mandibular arch a bar connector is default choice
what maxillary connectors can you get
- anterior palatal strap
- mid palatal strap
- anterior/posterior strap (ring)
- horseshoe
- posterior palatal strap
what different about acrylic designs compared to cobalt chrome
- design are pretty much the same
- but acrylic don’t tend to have bars = not good in cross sectional dimension, don’t have lower lingual bar in acrylic
what other type of maxillary connectors can you get in acrylic
- ‘spoon’
- modified ‘spoon’
- every
what does the ‘every’ design do
- maintains space between teeth
- doesn’t allow distal drift as has metal connector at back of last standing teeth
what mandibular connectors can you get
- lingual bar
- lingual plate
- dental bar
- sublingual bar
- labial bar
when is a lingual bar used
is the go-to design for lower dentures
what are the advantages and disadvantages of lingual plate
- advantage = thinner and gives indirect retention
- disadvantage = covers all gingival margins
what are the advantages and disadvantages of a dental bar
- lots of indirect retention
- but covers all cingulum of teeth
- dental bar is actually a continuous clasp
what are the advantages and disadvantages of a sublingual bar
- advantage = its below the tongue to patient is not as aware of it
- disadvantage = need to record function of the flow of the mouth well, as if not it will be very uncomfortable for the patient
when is a labial bar used
- used only when the lower anterior teeth are lingually inclined preventing lingual bar
- very rare
why are mucosal borne lower dentures generally not recommended
- due to lack of mucosal support