Clinical Techniques of RPDs (1) Flashcards
Describe treatment planning for RPDs following diagnosis
- Pain relief
- Initial prosthodontics
- Surgery / periodontal / orthodontics / restorative dentistry
- Definitive prosthodontics
Describe the clinical stages of RPD production
- Preliminary impressions
- Recording occlusal relationship for articulation of study casts
- Master impressions for working casts
- Castings trial / altered cast impressions
- Trial protheses
- Insertion
- Review
Why must study casts be articulated and surveyed?
To allow RPD design and custom impression trays to be made
Name 4 things which should be recorded in a preliminary impression
- All surfaces of all teeth
- All of the palate back to junction of hard and soft palate
- Bounded saddle areas to full depth of sulci
- Distal extension saddle areas to hamular notch (upper) and retromolar pad (lower) to full functional width and depth of sulci
Describe 5 features of a tray used to take an impression
- Rigid in use
- Sufficient extension to support impression of all structures
- Incorporate occlusal stops
- Have a robust, preferably integral handle
- Capable of withstanding autoclave sterilisation if reusable
What are box trays designed for?
To be used where teeth are present
Describe why alginate impressions in rigid stock trays are useful
- Give accurate impressions for good quality casts
- Prepare satisfactory design, assess occlusion and enable custom impression trays to be constructed
Name 3 places where dead space is likely to occur
- Saddles
- Palate
- Reflection of sulci
What is the best way to prevent dead space ruining an impression?
Adapt the tray
Explain how a tray is adapted to remove dead space
- Thermoplastic impression compound added to tray
- Hot wax knife removes excess impression compound or teeth indent
- Alginate places over the compound and impression taken normally
Describe how to take a lower impression
- Stand in front of patient while seating tray
- Half close mouth
- Tongue up and forward to touch the upper lip
Give 4 steps of disinfecting alginate impressions
- Rinse with cold water for 30 secs
- Immerse Perform for 10 mins
- Rinse in water and remove excess
- Wrap in damp gauze, plastic bag and label as disinfected
What is Immerse Perform?
Persulphate compound - Organic acids
Describe 6 things which may be included on prescription to the laboratory with alginate impression for a RPD
- Patient details
- Registration rims (+/-)
- Impression material to be used for master impressions
- Trays (+/-)
- RPD Design
- Date to be ready for
What is the function of articulating study casts when designing RPDs?
Avoid premature occlusion on prosthesis