Prosthodontics L4 -surveying and partial denture design principle Flashcards
what is this called
the surveyor
what are these
surveyor tools
what is the name of the rod and what is used for
analysing rod : analyses tooth and tissue undercuts and determines the path of insertion for the denture
what is the graphite marker used for
scribe tooth and tissue undercuts on the model with graphite marker
what is a undercut gauge used for
it is used to measure the desired amount of undercut for the clasp material used
what is the chisel used
used to trim the blocked out undercut areas on the model
the universal joint allows the platform to be moved in any direction. what are the names of the tilt and what do the tilts determine
the tilts are recognised as anterior and posterior tilt. these tilts help determine the path of insertion for the denture.
why would this tilt be unsuitable
Unsuitable: Note the space between analysing rod and tissue. The finished denture would also be fabricated with this space.
why is this tilt suitable
Suitable: the analysing rod is snug against the tissue the finished denture would fit like this also.
what is this image showing
no undercuts
what is this image showing
undercut present - space between analysing rod and tooth
once the path of insertion is decided what must be done using the analysing rod
Once the path of insertion is decided, a line is drawn on both sides of the model and one on the back of the model as shown using the analysing rod
This allows the model to be put back on a surveyor at the same angle at a later date. Ie: The table would be tilted so the analysing rod lines up with the lines on the model
where is the undercut area
below the survey line
what type of clasp would be used if you have a diagonal survey line
Occlusally approaching clasp.
Stainless steel or Cobalt Chrome, the clasp should taper towards the retentive tip of the clasp. The final third of the clasp is below the survey line and will flex over the tooth and into the undercut area.
what type of clasp would be used with a high survey line
Gingivally approaching clasp is used, as two thirds of an occlusally approaching clasp cannot approach from above the survey line.
Positioned on or below the survey line
what calsp would be used with a low survey line
Gingivally approaching clasp can be used and would be less visible than an occlusally approaching clasp may be positioned mesial, central or distal, distal may be more hidden so better aesthetically and is positioned on or below the survey line.
an undercute gauge determines the amount of undercut an occlusally approaching clasp can engage depending on the material it is made of.
Cobalt chrome clasp can utilise an undercut of up to
Stainless steel clasp can utilise an undercut up to
Gold clasp can utilise an undercut of up to
Cobalt chrome clasp can utilise an undercut of up to 0.25 (brittle material)
Stainless steel clasp can utilise an undercut up to 0.5mm (More flexible material can engage a deeper undercut)
Gold clasp can utilise an undercut of up to 0.75mm ( more flexible than both chrome and stainless steel)
occlusal rests habe three functions what are they
- Provide support for the denture.
- Directs occlusal loads down the long axis of the teeth.
- Can provide indirect retention
what are the cummer arms for in the lingual bars
Lingual bar with cummer arms to resist posterior uplift of the denture. (Indirect retention)
what is the minimum space required from the sulcus depth to the gingival margin to prescribe a lingual bar
a minimum of 7mm is required from sulcus depth to gingival margin
what must there not be in order to be prescribed a dental bar
To use this design ensure there is no spacing between anterior teeth.
what does the dental bar allow the freeing of
This design frees up the gingival margins and lingual mucosa so is more hygienic than the plate design
the dental bar requires a minimum total crown height of ………mm for this connector to be used
bar width of ………. mm and …………… mm clearance from the gingival margin and ………….. mm clearance from the incisal tip of the tooth.
The dental bar requires a minimum total crown height of 9mm for this connector to be used.
Bar width of 5mm and 2mm clearance from gingival margin and 2 mm clearance from the incisal tip of the tooth as shown.
what is the nae of this clasp
RING CLASP COBALT CHROME WITH OCCLUSAL REST
what is the name of this clasp
OCCUSALLY APPROACHING CIRCUMFERENTIAL CLASP,
COBALT CHROME WITH OCCLUSAL REST
what is the name of this clasp
THREE ARM CLASP COBALT CHROME WITH OCCLUSAL REST
what is the name of this clasp
STAINLESS STEEL OCCLUSALLY APPROACHING CLASP
what is the name of this clasp
GOLD GINGIVALLY APPROACHING CLASP
what are these two clasp variations of
variations of T clasp
what is the name of this clasp
t clasp
what is the name of this clasp
i bar clasp
what is the typical bar width of a mid palatal bar, posterior bar or anterior bar
typical bar width between 7 and 12mm
when inserting a denture into the mouth a force is applied to the clasped tooth, in order to prevent tooth movement. what is required to prevent a tooth movement
a reciprocal component is required as indicated in the image
