Preparation of the mouth/teeth Flashcards
What are the 4 stages of a restorative treatment plan
- Immediate
- Hygienic (preparatory phase)
- Corrective (reconstructive) phase
- Maintenance
Which stage of a restorative treatment plan does the provision of an RPD fit in
corrective (reconstructive) phase
Clinical stages of partial denture construction
- primary impressions
- primary jaw registration (if required)
- mounted, surveyed study casts
- design denture
- tooth prep and master impressions
- jaw registration
- trial
- delivery
- review
Do you always need record blocks
no, if enough teeth that you can occlude then you don’t need one but if someone is lacking teeth then it may be difficult to occlude.
Ask lab to make primary record blocks so you can see how the teeth meet and then put it into the articulator
How do you know what to prep
by surveying the cast to determine undercuts and path of insertion
how much prep should you do
minimal
What comes under ‘mouth preparation’
- initial prosthetic treatment
- surgery
- periodontal treatment
- orthodontic treatment
- fixed prosthodontic treatment and endontics
- tooth preparation
What is involved in initial prosthetic treatment
- repairs and additions
- temporary relines
- occlusal adjustment
- treatment of denture stomatitis
What is involved in pre-prosthetic surgery
- remove retained roots/ unerrupted teeth
- remove pathology
- improve contours of edentulous areas by reducing bony prominences and hyperplastic soft tissue
- eliminate prominent fraenal attachments e.g. torus palitinus(?)
What is involved in periodontal treatment
- establish health in periodontal tissues
- assess patient motivation
- detailed instruction in OH procedures
- scaling and root planing
- periodontal surgery (if pockets >6mm)
What is involved in orthodontic treatment
- to optimise space
- optimise path of insertion
- to optimise abutment alignment
- cleft patients, hypodontia patients, periodontal patients
What is involved in fixed prosthodontic treatment and endodontics
- should follow denture design and precede denture construction
- establishes clinical integrity of teeth before master impressions recorded
- facilitates provision of crowns (and/or teeth) with guide planes, rest seats r.g. cingulum rests on canines etc
- endo is better done before placing a crown
What is involved in tooth preparation
- provide rest seats
- establish guide surfaces
- modify unfavourable survey lines
- create retentive areas
Why might we want to prepare a rest seat
- to produce a favourable surface for support
- to prevent interference with occlusion
- to reduce prominence of the rest
How do we prepare rest seats on maxillary anterior teeth, why
Cingulum rests
a well developed cingulum allows prep to stay within enamel
use a cylindrical diamond stone with a rounded tip
How do we prepare rest seats on mandibular anterior teeth, why?
Incisal rest seats are used.
The lingual surface is too vertical and cingulum too poorly developed to avoid penetrating enamel
What are 2 alternatives to tooth preparation
- produce a rest seat in composite applied to cingulum area
2. bond a cast metal cingulum to tooth
How should you prepare rest seats on posterior teeth
- reduce marginal ridge
- saucer-shaped rests to allow some horizontal movement and dissipation of occlusal forces
- should be deep enough to allow a rest of at least 1mm thick
- if no space occlusally for a clasp to extend buccally from an occlusal rest, the preparation must be extended as a channel to the buccal surface
What are guide planes
two or more parallel axial surfaces on abutment teeth, which limit the path of insertion of a denture
they may occur naturally, but more often need to be prepared
what do guide planes provide
- increased stability
- reciprocation
- prevention of clasp deformation by a deep undercut
- improved appearance
How should guide planes be prepared
- tooth surfaces prepared to be parallel to each other and the path of insertion
- guide surface should extend vertically 3mm but be kept as far from the gingival margin as possible
- no more than 0.5mm enamel should be removed
If the dentist has done guide planes what does that mean
there is just one path of insertion for the denture and it helps in the stability
How can retentive areas be created
by acid-etched ultrafine/hybrid composite
need a broad area of attachment of the restoration to the enamel
What impression material should you use for master impressions
- alginate (?)
- silicone (?)
- polyether e.g. pentamix
- polyvinylsiloxane e.g. extrude
+ correct adhesive
When should you not use alginate as an impression material and why
for chrome as not dimensionally stable
How do you clinically take a master impression
- obtain accurate impression of denture bearing area
- use individual tray
- use appropriate impression material
What do you ask the lab for after taking a master impression
- produce master cast
- for cobalt chrome needs to be improved cast
- produce record blocks so need to duplicated the improved cast
- produce trial denture
- produce finished denture
why do we ask the lab to duplicate casts
one is made of 100% dental stone and the other made of improved stone so it doesn’t chip or damage because if they get damaged back to square 1
How can you adjust the periphery of an individual tray if it needs it
- by using green thermal plastic material
- Heat on bunson burner to make it flow and use it in distal aspect or upper tray or lingually on lower so that material flows under tongue
- Don’t need to extend to the sulcus in RPD so impression may be more extended than RPD
- Green stick can spark if you put it in right away - lay it where you want to add it. Put in hot water. Still soft but firm so it can flow and record tissues in that area and once it is chilled then you add adhesive and took full impression
What can make taking an impression hard
- beard/ mustache
- gag reflex
where do you stand for an upper impression
behind them
where do you stand for a lower impression
in front (thumbs on mandible)
What do you do with their lips and tongue when taking an impression
lips out the way and tongue lifted up
What do we not want to see in our impressions
- air bubbles
what do we want to see on our impressions
- nice sulcus form
- rugae on palate
- all the teeth
- frenal attachment
- all anatomy
