Treatment Plan + Denture Design (clinic) Flashcards
At the initial appointment, what examinations and histories should be undertaken? What else should be done?
- MHx
- DHx
- Extra oral exam (soft tissues + overall appearance)
- Soft tissues (intra oral)
- Occlusal
- Pros Assessment (assess any existing dentures)
- Periodontal (gingival)
- Hard tissue
- Radiographic Exam
- Study casts
- Radiographs
-Take primary impression
What should be included in the DHx?
Pt attitude, expectation, previous dental experience
What should be checked in an extra-oral exam?
- Facial form
- Lip form and support
- Facial height
- Appearance
- Interocclusal distance
What should be checked in an intra-oral exam?
- Hard and soft palate
- Cheeks and lips
- Tongue and floor of mouth
- Oropharynx
- Upper and lower ridges of edentulous areas
What should be checked in the gingival exam?
- Colour, contour, consistency, texture
- Signs of pathology (e.g. hyperplasia and exudate)
- Plaque + calculus scores
What should be checked in an occlusal exam?
- Arch form
- Axial inclination of teeth
- Interocclusal distance
- Intercuspal and retruded contact positions
- Movement to eccentric contact positions
- Interfering coontacts
- TMJ movements
- Mandibular movements
What should be checked in a Pros assessment?
Out of mouth:
- denture design
- Material used
- Maintenance and modifications
- Unusual patterns/rate of wear
- Denture hygiene
Inside mouth:
- Extensions
- Retention and stability
- Compatability with neutral zone and hard/soft tissues
- Appearance
What radiographs should be taken for denture design?
OPG to detect adverse anatomical or pathological conditions
-Supplementary BWs and PAs if necessary
What impression material should be used for study casts? What material should be used to create teh casts? What sort of articulator should be used for exam?
- Alginate
- Yellow stone
- Semi-adjustable
What should be done if there are insufficient opposing teeth to reliably relate casts in intercuspal position?
- Construction of temporary bases and wax rims (using wax, shellac base-plate or cold cure acrylic resin)
- Obtain jaw relation records
What sequence should be followed in designing a partial denture?
- Saddle
- Support
- Retention
- Connectors
- Simplification
What is involved with the saddle stage?
- Consider teeth to be replaced and whether you can justify each artifical tooth provided.
- Outline proposed saddles on “Dental Prosthesis Design Record”
What is involved in the support stage?
- Basically the part of the denture that prevents vertical displacement towards gingiva/soft tissue (the circular part that sits on the tooth and that clasps attach to)
- Assess ability of remaining teeth to support saddles
- If short saddles bounded by healthy teeth should be tooth supported
- Distal rests on anterior abutment and mesial rests on posterior abutment
- For free-end saddles rests on mesial aspect of occlusal surface of abutment teeth to minimise unfavourable forces
- Rests should be drawn on Dental Prosthesis Design Record in red pencil
What is involved in the retention stage?
-Placement of clasps to facilitate retention (vertical displacement in occlusal direction)
What other forces besides clasps provide retention?
-Adhesive forces between saliva and denture base, cohesive forces within saliva and shape of denture
What should be considered when placing the clasps?
Location of retentive undercuts
- Should be easily approached by clasp arm
- Canine and premolar gingival approaching
- Molar occlusal approaching
- 2mm clear of gingival margin to avoid irritation
Clasp properties:
- Length: Co/Cr clasps 15mm to be resilient
- Sufficient flexibility?
- Sufficient rigidity when necessary?
- Cover minimum tooth surface and gingival tissue?
Horizontal undercut depth
- 0.25mm for Co/Cr
- 0.75mm for stainless steel
Undesirable undercuts
- May modify the design of denture clasps
e. g. buccal undercut might prevent gingival approach clasps - High survey line on lingual might require recontouring of surface or selection of alternate tooth
Aesthetics
-Avoid metal display when speaking, smiling, eating
Number of clasps
- Bilateral tooth borne saddles: diagonal clasping (anterior abutment on one side, posterior abutment on the other)
- Bilateral tooth borne saddles with long saddle: 3 clasps (Clasp both ends of the longer saddle + one of the abutments on the opposite side)
- Free end saddle: bilateral gingival approaching clasps extending to the MB to minimise distal displacement
- All clasps need to be reciprocated by a reciprocating arm or extension of denture base above survey line
- Clasps should be marked in place on Dental Prosthesis Design in red pencil
- A reciprocal arm on the opposite side above the survey line needs to be placed so clasp so that lateral forces are not exerted on the tooth resulting in displacement
What are the reasons for partial denture?
- Mastication: but very limited improvement
- Speech (tongue may not have appropriate places for tongue to lean against)
- Appearance
- Comfort
- Prevent further breakdown
