mouth preparation and master cast Flashcards
patient treatment phase I:
-relief of pain and infection
-collection of diagnostic data (diagnostic cast and mounting)
-develop treatment plan (design RPD)
-patient education and motivation
-occlusal equilibration
patient treatment phase 2:
-removal of deep caries, temp restorations
-extraction of non-retainable teeth
-preprosthetic surgery: tuberosity reduction
-periodontal treatment, plaque control
-interim prosthesis: function, esthetics
-occlusal equilibriation, may need changes after extractions
patient treatment phase III
-definitive endodontic treatment
-definitive restorative treatment (surveyed crowns if needed, fixed partial dentures, if appropriate)
-occlusal plane correction
patient treatment phase IV
construction RPD
patient treatment phase V
-post insertion care
-periodic recall
-continued plaque control
diagnostic casts
preliminary design of RPD
identify tooth modification areas
perform tooth modifications according to
according to RPD diagnostic cast design
-QA worksheet
enamoplasty for RPD steps
- develop guide planes
- enlarge embrasure for minor connectors
- lower height of contour
- create undercuts if needed
- prepare rest seats (occlusal and lingual: chevron)
with developing guide planes for enamoplasty for RPD (step 1) what are the requirements:
-proximal: adjacent to edentulous areas
-ML: stress-release clasps ML minor connector
-lingual: reciprocal clasp
with lowering height of contour for enamoplasty (step 3) what are the requirements
-proximal 2/3 circumferential retentive clasp
-reciprocal clasp
-lingual guide plate
confirm that the preparations are parallel to path of insertion in what following sequence (guide planes, embrasures, alter height of contour):
- prepare guiding planes
- enlarge embrasures for minor connectors
- reposition the survey line to reduce interferences to framework placement an enable most ideal clasp placement (make sure lowered enough)
used when slightly insufficient retentive undercut
-slopped buccal or lingual surface
undercut preparation
(need to reconsider other areas for undercut or need surveyed crown)
undercut preparation with
round-ended tapered diamond (where tip of retentive clasp will go)
this is done after adequate preparation for guiding planes, survey line alterations
rest seat preparations
if you are unable to attain adequate depth with enamel for rest seat
remove small amount of opposing tooth structure and be sure to remake impression of opposing arch
master cast class III RPD impression technique/preferred at UMKC
custom tray/elastomeric material
not border molded
medium bodied PVS
for master cast extension RPD impression, what is an important source of RPD support and what is important to accurately record
residual ridge important source of RPD support
-important to accurately record max tissue support area
concept where
-distribute occlusal forces over as many teeth and as much soft tissue as possible
-not overload teeth or tissue
-increased stability and retention
-less frequent reline
broad-stress distribution concept
what is the problem with tooth-tissue supported rpds
due to lever effect of distal extension base, occlusal pressure is concentrated on the distal end of the base
periodontal membrane allows 0.25+/- 0.1 mm (teeth basically)
and
muco-periosteum allows for 2+mm movement (palate or tongue area)
what is the solution for tooth/tissue supported RPDS
-equalize support derived from tissue and teeth
-to distribute load to both natural and artificial dentition and minimize base movement
master cast: extension RPD impression options
- custom tray/elastomeric material
-border-molded tray
-one step impression - corrected (altered) cast technique
-two-step impression - impression of teeth and residual ridge
- impression of residual ridge areas using framework
master cast: altered cast impression step one explained
- impression of teeth and residual ridge
-alginate/stock tray or alginate/custom tray
-framework fabricated on 1st cast (framework less precise than with elastomeric impression
master cast: altered cast impression step two explained
- impression of residual areas only
-sectional trays added to framework
-border-molded
-elastomeric material
master cast: altered/correct cast steps explained
- residual ridge removed from 1st cast
retentive dovetails created - framework/impression luted to altered cast
-cast and impression boxed
-residual ridge areas poured with yellow stone - final cast
