prep of the mouth and teeth for RPD definitive impressions Flashcards
what are the 4 stages in a restorative tx plan?
immediate tx initial phase (hygienic or preparatory) reconstructive (corrective) phase maintenance
what are the clinical stages of RPD construction?
primary impressions primary jaw registration mounted, surveyed study casts design denture tooth prep and definitive impressions jaw registration trial delivery review
what may be included in mouth prep?
initial prosthetic tx pre-prosthetic surgery periodontal tx orthodontic tx fixes prosthodontic tx and endodontics tooth prep
what would be done in initial prosthetic tx?
repair and additions
temporary relines
occlusal adjustment
tx of denture stomatits
what is pre-prosthetic surgery?
remove retained roots/unerupted teeth
remove pathology
improve contours of edentulous areas-by reducing bony prominences and hyperplastic soft tissue
eliminate prominent fraenal attachments
what is periodontal tx?
establish health in periodontal tissues assess px motivation detailed instruction in oral hygiene procedures scaling and root planing periodontal surgery
what is orthodontic tx ?
to optimise space
to optimise abutment alignment
cleft, hypodontia, perio px
why is fixed prosthodontic tx used?
should follow denture design and precede denture construction
establishes clinical integrity of teeth before master impressions recorded
facilitates provision of crowns with guide planes rest seats etc.
what is the purpose of tooth preparation?
provide rest seats
establish guide surfaces
modify unfavourable survey lines
create retentive areas
what instrument is used to shape enamel surfaces?
rotary diamond instruments
what is ideal rest seat prep?
produce favourable tooth surface for support
prevent interference w/ occlusion
reduce prominence of rest
describe a maxillary anterior rest seat
a well-developed cingulum allows prep to stay w/i enamel
cylindrical diamond stone w/ rounded tip
describe a mandibular anterior rest seat
lingual surface undeveloped cingulum - incisal rest seats used as cingulum will penetrate enamel
what are the alternatives to rest seat prep?
produce rest seat in composite applied to cingulum area
bond a cast metal cingulum to tooth
describe a posterior rest seat
reduce marginal ridge
saucer shaped to allow horizontal movement and dissipation of occlusal forces
rest at least 1mm thick
what should be done if there is no space occlusally for a clasp to extend buccally from an occlusal rest?
prep must be extended as a channel on to the buccal surface
what are guide planes?
2 or more parallel axial surfaces on abutment teeth, which limit the path of insertion of a denture, may occur naturally but prob need prepared
what do guide planed provide?
increased stability
reciprocation
prevention of clasp deformation
improved appearance
how are guide planes prepared?
tooth surfaces prepared to be parallel to each other and the path of insertion
extend vertically 3mm kept away from gingival margin
no more than 0.5mm enamel removed
what would unfavourable survey lined cause?
clasp would be positioned too close to occlusal surface, causing occlusal interference -> px annoyance
deformation of clasp
how are retentive areas created?
addition of acid-etched composite
broad area of attachment of restoration to enamel
ultrafine/hybrid composites
what are the clinical stages of master impression?
obtain an accurate impression of the denture-bearing area
use individual tray
use an appropriate impression material
what are the lab stages of master impressions?
produce casts produce casting (if cobalt chrome) produce record blocks produce trial denture produce finished denture
what are individual trays?
made on primary casts from heat-cured or light cured acrylic
try in
adjust periphery as required
what are the options for impression material?
alginate
polyvinylsiloxane
polyether
+ adhesive
