Treatment planning for fixed pros Flashcards
What features are relevant when checking occlusion for fixed pros?
incisor relationship
excursions of mandible
canine guidance
group function
What are the indications for veneers
Improve aesthetics
Change teeth shape and/or contour
Correct peg shaped laterals reduce or close proximal spaces and Diastemas
Align labial surfaces of instanding teeth
What are the contraindications for veneers?
poor OH
high caries rate
interproximal caries
gingival recession
root exposure
high tip lines
if extensive prep needed
labially positioned, severely rotated and overlapping teeth
extensive TSL/insufficient bonding area
heavy occlusal contacts
severe discolouration
When are inlays/onlays indicated?
Inlays - Isthmust greater than 1.5-2mm, cusps in tact, previous failed direct, occlusal/proximal caries
Onlays - As above but cusps broken down, and a large isthmus.
What are the disadvantages of inlays/onlays?
active caries and periodontal diseases
time
cost
Why would you use a crown to restore teeth?
Protect weakened tooth structure
Improve/restore aesthetics
Use as a retainer for fixed bridge
When indicated by design of RPD
Restore tooth function
When would you not restore with crowns?
Active caries and periodontal disease
More conservation options available
Lack of tooth tissue for preparation
Unable to provide post and core
Unfavourable occlusion
What are the principles of crown preparation?
Preservation of tooth structure
Retention and resistance form
Structural durability
Marginal integrity
Preservation of periodontium
Aesthetic considerations
Why would you preserve sound tooth?
To avoid weakening tooth structure and damaging pulp
Prostethesis will never be as good as natural tooth
What does under preparation result in?
Poor aesthetics
Over built crown with periodontal and occlusal consequences
Restorations with insufficient thickness
What does over preparation result in?
Pulp exposure risk and tooth strength compromised
What does retention form prevent?
Removal of restoration along path of insertion or long axis of tooth preparation
What does resistance form prevent?
Dislodgement of restoration by forces directed in an apical or oblique direction and prevents any movement of restoration under occlusal forces
How do you create retention and resistance form?
Taper
Length of walls
Path of insertion
Grooves and slots
How do you achieve structural durability?
occlusal reduction
functional cusp bevel
axial reduction
What are the types of finish line configurations?
knife edge
bevel
chamfer
shoulder
bevelled shoulder
To help preserve the periodontium, how should the margins of the crown be prepared?
smooth and fully exposed to cleansing action
Placed where the dentist can finish them and patient can clean them
Placed supragingivally or at gingival margin
Why replace teeth with a bridge?
Aesthetics
Maintain occlusal stability
Function
Periodontal splinting
Restoring occlusal vertical dimension
Patient preference
Why would you not replace teeth?
Damage to tooth and pulp
Secondary caries
Effect on periodontium
Cost
Failures
What are the types of bridge design?
Cantilever
Fixed-fixed
Adhesive/resin bonded
Conventional
Hybrid
Fixed moveable
Spring cantilever
What do you need to communicate to patients to ensure you get informed consent for fixed pros?
Invasiveness/reversibility
longevity and success rates
Possible complications
Time involved
Costs
Alternative options
What treatment performed
Why it is necessary
Consequences of not having treatment
What risks there are
What is the risk of devitalisation when performing a direct for a crown or bridge?
Tooth has a 20-30% chance of devitalisaion, and would require endo.
What is meant by the term biological width?
The biological width is defined as the dimension of the soft tissue, which is attached to the portion of the tooth coronal to the crest of the alveolar bone.
What is the effect if an indirect margin encroches on biological width?
Invasion of biologic periodontal space for additional retention will cause iatrogenic periodontal disease with a premature loss of restoration.
What aspects determine if a tooth is restorable?
Amount of remaining strucutre
Bone levels (including no caries at bone level)
Active disease management
Sufficient biological width
