Prosthetics Flashcards
what are the causes of tooth loss ?
caries,
periodontal disease,
trauma,
planned orthodontic extractions
what are the consequences of tooth loss ?
anatomical,
aesthetics,
functional,
psychological
what are the anatomical consequences of tooth loss ?
bone loss,
lip support,
tooth movement,
TMJ
what are the options for replacing missing teeth ?
nothing,
conventional or resin retained bridges,
dentures,
implant retained prostheses
what is meant by the ‘shortened dental arch concept’?
able to function well with 5-5
in what case are people with missing teeth unlikely to have removal partial dentures ?
when they still have 21 remaining natural teeth
what are the advantages of fixed bridges ?
better patient acceptance,
better tolerance,
easier to keep clean,
less plaque accumulation
what are the disadvantages of fixed bridges ?
cost,
invasive (conventional)
operator sensitive,
more technically demanding
what are the advantages of removable dentures ?
non invasive, reversible, young people, can be added to following further tooth loss, atraumatic, restore long spans, less expensive, can be modified
what are the disadvantages of removable dentures ?
psychological,
removable,
less acceptable,
damaging effects
what are the possible damaging effects of removable dentures ?
decalcification, caries, inflammation of gingival tissues, inflammation of mucous membrane, plaque, direct trauma from components e.g. clasps
what are the advantages of implants ?
good success rate,
excellent stability and retention
what are the disadvantages of implants ?
cost,
operator sensitive,
cannot restore alveolar bone
what factors need to be considered for partial dentures ?
number and distribution of missing teeth, stats of abutment teeth, soft tissue loss, anterior tooth spacing, restoration of occlusal face height, patient preference and cost, interim replacement
what are the hygienic principles of RPD design ?
avoid unnecessary coverage of gingival tissues,
RPD components 3 mm from gingival margins,
create space for natural cleansing and OH measures
how do indirect restorations affect RPD design ?
should be planned in conjunction with RPD,
rest seats, undercuts and milled guide planes can be incorporated,
improved fit, retention and reduced bulk of RPD for the patient,
cast restorations should not be construed without a final denture design
what is the process of design for an RPD ?
logical sequence of 6 core elements
- saddels
- support
- retention
- reciprocation
- indirect retention/anti-rotation
- major connector
define support
resistance of movement towards the mucosa
what are the 3 types of denture support ?
tooth,
tooth and mucosa,
mucosa
what are the 3 types of tooth rest ?
cingulum,
occlusal,
incisal
what is required for a mucosally supported denture ?
maximum extension -
hamular notch, tuberosities,
retromolar pad
define retention
resistance away from the tissues
how is direct retention achieved ?
mechanical eg clasps and precision attachments,
path of insertion,
physical
what are the key points of RPD design ?
avoid unnecessary gingival coverage,
use tooth support where possible,
wide extension of mucosally supported saddles,
only two retainers per denture if possible,
rigid connectors
bilateral, even occlusal contacts
what are the advantages of acrylic dentures ?
cheap,
easy to construct,
easy to modify
what are the disadvantages of acrylic dentures ?
weak,
non rigid,
require bulk for strength,
potential soft tissue damage
what are Every’s principles ?
point contact between adjacent standing and artificial teeth,
wide embrasures,
no occlusal interferences,
3 mm gingival clearance,
correct denture extension with accurate fit and the polished surfaces to assist muscular control,
distal stop
acrylic
how are dentures classified ?
kennedy's classification (saddles) Craddock classification (support)
describe Kennedy’s classification
I - bilateral free end saddle
II - unilateral free end saddle
III - bounded saddle
IV - anterior bounded saddle that crosses the midline