Combining Dentures with Crown & Bridgework Flashcards
Why might crowns be placed before dentures are constructed?
- heavily restored posterior teeth are commonly used as abutments
- placing a crown increases longevity
What adjustments can be made to crowns when planning to incorporate into a denture design?
- rest seats
- guide planes
- palatal or lingual
- buccal undercuts
- CoCr clasp
- 0.25mm
- CoCr clasp
When incorporating crown or bridgework into dentures, which should be designed first?
denture design should be carried out to ensure components included in the crown are utilised
What preparations may have to be made to crown preps when incorporating dentures and crown and bridgework?
- increased occlusal reduction
- due to tight occlusion
- increased palatal or lingual reduction
- due to tilt of tooth
Outline the process of constructing a denture incorporating crown and bridgework
- assess whether tooth is suitable for modified crown prep
- prepare tooth according to planning
- take impression of crown press and denture bearing area together
- polyether
- UV monophase
- place temporary crown while definitive is constructed
- remove temporary crown and try in denture framework and crown
- recement temporary crown
- at denture delivery cement the final crown
- crown must be well seated
- remove excess cement
- immediately insert denture and seat
What are the most common types of precision attachments used when crown and bridgework is incorporated into dentures?
- studs
- tube locks
What are the challenges faced when using precision attachments for dentures?
- oral hygiene
- must be excellent
- very challenging to clean
- risk of secondary caries
- especially root surface
- technician
- crown and bridgework technician
- denture technician
- must have good communication
- repairs and replacements
- notes must be thorough
- exact details
- type of attachment
How do traditional stud precision attachments work?
- ball attachment on crown and socket on denture
- usually canine or second premolar
- tooth must be RCT
- post and diaphragm constructed
- ball located on end of post
- ball protrudes so crown height is required
How do zest anchor precision attachments work?
- ball attachment on crown and socket on crown
- better for smaller teeth
- tooth must be RCT
- prefabricated drill used to place zest
- fibreglass ball
- cold cured into denture
- easily replaced
- drill out old one
- cold cure new one
- wears over time - retention reduces after a few years
Why might survey lines be modified when constructing crowns or dentures?
- modified to make more favourable
- denture designed first
- composite
- crowns
- instruction given to technician to increase bulk
- contingency planning for future dentures
How can crown be made to fit existing dentures?
- if a tooth fractures or a restoration comes out, a denture which fits perfectly may require replacing
- easier with metal crowns
- temporise the tooth and carve until the denture fits
- take impression of tooth without denture in
- prepare the tooth for a crown
- place core material if required
- take impression with duralay using impression from temporary
- pattern resin
- takes shape of the original temporary filling and tooth
- reseat duralay and check denture fits
- can make small adjustments with so flex discs
- impression, interocclusal record and duralay sent to lab
- duralay fit to cast and wax up to gingival margin
- ensure exact fit
- duralay fit to cast and wax up to gingival margin
- crown sent back to clinic
- can make minor adjustments
- cement crown and seat denture
What contingency planning can be carried out when designing crowns?
- crowns can be designed with future dentures in mind
- do not have to currently be making denture
- crown key teeth
- e.g. keep a molar in each quadrant
What is a tunnel preparation for a crown?
- crowning of a periodontally involved tooth
- stable periodontal condition
- allows cleaning through the furcation
How can denture design be simplified using crown and bridgework?
- anterior bridge to avoid single tooth saddle
- single anterior tooth in saddle is prone to breakage
- patient regularly attends for repairs
- replace tooth with cantilever bridge
- adhesive or conventional
- single anterior tooth in saddle is prone to breakage
- avoidance of dentures using bridges or implants
- single tooth gap
- fixed-fixed can splint periodontally involved teeth
- low load situations for bridge (denture opposing)
- by accepting spaces
- no aesthetic or functional problems
- no suitable abutment
- overeruption of opposing teeth
- must monitor
- implants difficult with medially tipped adjacent teeth
- challenging to clean
What are the challenges of tooth wear rehabilitations?
- reduced OVD
- aim to increase
- lack of denture wearing experience
- lack posterior support
- staged approach
- transitional dentures
