Bridges Flashcards
what factors influence the success of adhesive bridgework (4)
quality of bonding surface
design of retainer
design of pontic
occlusal management
what pontic design should be used posteriorly for a bridge
dome shape
what are the two design aspects of a retainer for an adhesive bridge
0.5mm lingual and interproximal areas
0.1mm occlusal areas
what is the pontic design that should be used anteriorly for a bridge
modified ridge lap
how do conventional indirect restorations stay in place
resistance from opposing walls of the preparation prevent displacement
for maximum retention these walls should be parallel
however most walls will have 7-9 degree taper to long axis of the tooth
what are four types of conventional bridges
fixed fixed
cantilever
fixed moveable
spring cantilever
how should the abutment teeth at either side of the pontic be prepared with regards to their walls
the walls should be parallel
how may we overcome the problem of providing a bridge to teeth that are tilted
retainers with separate parts of insertion
eg - moveable connector
what are unfavourable tooth contacts
on cuspal inclines
no contact at all
what may contacts on cuspal inclines lead to
lateral forces being applied to teeth
what are the 5 properties of occlusal forces
magnitude
velocity
frequency
duration
direction
what are the three types of occlusal guidance
canine
group function
balanced articulation - complete dentures only
why is canine guidance preferred
simple to produce guiding contacts on anterior restorations
posterior teeth are restorations are protected
what are facebows used for
mounting upper casts only
transfers the relationship between maxillary teeth and axis of rotation from patient to articulator
what makes up the assessment to see if a patient is a suitable candidate for bridgework
patient preference
age - not too old/young
attitude to dentistry
medical conditions
diet/ smoking/ cost
dentist skill
consent
what are adhesive bridges
those retained by metal wing(s) which are bonded onto minimally prepped enamel
how do you improve bridge retention
maximise available bonding surface area
sandblast fitting surface of wing
cutting notches/ grooves and locating margins
incorporate rest seats
why is only one abutment preferred for adhesive bridges
oral hygiene
divergent guide paths
what are the two main types of bridges
conventional (crowns on abutment teeth)
adhesive (wings)
what are two types of bridge designs (can be used for either conventional or adhesive)
fixed fixed
cantilever
when would a fixed moveable bridge be used
when you cannot achieve a common path of insertion
what is a spring cantilever bridge and when would it be used
on pontic attached to end of metal arm that runs across the palate to rigid connector on palatal side
used when the anterior teeth are unrestored and there is a suitable posterior tooth
what are the five types of pontic connector designs
wash through
dome
modified ridge lap
ridge lap
ovate
what is LAVA 3M ESPE
3-4 unit bridge milled zirconium oxide
what should be used to cement metal or metal ceramic conventional bridges
GI or RMGIC luting cement (aquacem or relyX)
what should be used to cement adhesive bridgework
panavia - anaerobic dual cure resin cement
what should be used to cement all ceramic bridgework
NEXUS - dual cure resin cement
why should distal cantilevers be avoided
concerns that occlusal forces on pontic will produce leverage forces on abutment tooth and cause it to tilt
what is combination syndrome
where a denture opposes natural dentition and the forces exerted cause increased resorption of the alveolar ridge
