Fixed Prosthodontics Flashcards
What is the definition of fixed prosthodontics?
- Area of prosthodontics focused on permanently attached (fixed) dental prostheses
- AKA indirect restorations
What are the types of fixed prosthodontics?
- Veneers
- Inlays and Onlays
- Crowns
- Post and cores
- Bridgework
What is included in the history and examination?
- Patient complaint (CO)
- History of Presenting Complaint (HPC)
- Past Dental History (PDH)
- Past Medical History (PMH)
- Social History (SH)
- Family History (FH)
- Extra-oral Examination(EO)
- Intra-oral Examination (IO)
- BPE
- Dentition charting
- Occlusion
- Inter-arch space
- Inter-tooth space (mesio-distal)
What are you looking for in occlusion upon examination?
Incisal relationship
Excursions of the mandible
- Protrusion
- Retrusion
- Lateral
Canine guidance?
Group function?
What special investigations can you do?
- Sensibility testing
- Radiographs
- Study models
- Facebow
- Diagnostic wax up
What additional info is useful before diagnosis?
- Diet diary
- Plaque and gingivitis indices
- Full mouth periodontal chart
- Clinical photographs
- Microbiology, biopsy, haematology
What is the layout for treatment planning?
IMMEDIATE
- Relief of acute symptoms
- Consider endodontics and extractions
- Consider immediate denture/bridge
INITIAL (Disease Control)
- Extraction of hopeless teeth
- OHI and dietary advice
- HPT
- Management of carious lesions and defective restorations with direct restorations or provisional restorations
- Endodontics
- Denture design, wax up for fixed prosthodontics
RE-EVALUATION
- Re-assessment of periodontal status, confirm denture/bridge design
RECONSTRUCTIVE
- Perio surgery
- Fixed and removable prosthodontics
MAINTENANCE
- Supportive periodontal care and review of restorations
Why do we place 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 is the Gurel minimal preparation technique?
- Wax up
- Stent
- Intra-oral mock up
- Preparation into mock up (can use depth cut burs)
When should you not use veneers?
- Poor OH
- High caries rate
- Interproximal caries and/or unsound restorations
- Gingival recession
- Root exposure
- High lip lines
- If extensive prep needed (>50% of surface area no longer in enamel)
- Labially positioned, severely rotated and overlapping teeth
- Extensive TSL/insufficient bonding area
- Heavy occlusal contacts
- Severe discolouration
Why restore teeth with inlays/onlays?
- Tooth wear cases (Can Increase OVD)
- Fractured cusps
- Restoration of root treated teeth
- Onlays provide cuspal coverage
- Replace failed direct restorations
- Minor bridge retainers (not recommended)
Why would we not restore teeth with inlays/onlays?
- Active caries and periodontal diseases
- Time (Tooth preparation and laboratory fabrication required)
- Cost
Why restore teeth with crowns?
- To protect weakened tooth structure
- To improve or restore aesthetics
- For use as a retainer for fixed bridgework
- When indicated by the design of a RPD
- Rest seats
- Clasps
- Guide planes - To restore tooth function e.g. restore in OVD
Why 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 principle of crown preparation?
- Preservation of tooth structure
- Retention and resistance
- Structural durability
- Marginal integrity
- Preservation of the periodontium
- Aesthetic considerations
Why should we preserve tooth structure?
- Can weaken tooth structure unnecessarily
- Can damage pulp
What does under preparation of the tooth result in when doing a crown prep?
- Poor aesthetics
- Over built crown with periodontal and occlusal consequences
- Restorations with insufficient thickness
Why is retention important when crown prep?
- Prevents removal of restoration along path of insertion or long axis of tooth prep
Why is resistance important when crown prep?
- Prevents dislodgement of restoration by forces directed in apical or oblique direction
- Prevents movement of restoration under occlusal forces
How can retention and resistance be created in crown prep?
- Taper (ideal inclination of opposing walls 6-10°
- Length of walls
- Path of insertion
- Grooves and slots
Why is length of walls important for crown prep?
- Longer walls interfere with tipping displacement
What is path of insertion important for crown prep?
- Imaginary line along which restoration is placed onto or removed from preparation
- All features must coincide with the line
How is retention improved?
- Limited number of paths of insertion
Why is structural durability important for crown prep?
- Resto must contain bulk material that is adequate to withstand forces of occlusion
How is structural durability achieved?
- Occlusal reduction
- Functional cusp bevel
- Axial reduction
What are the finish line configurations for marginal integrity in crown prep?
- Knife edge
- Bevel
- Chamfer
- Shoulder
- Bevelled shoulder
What is the successful criteria for margins of the restoration?
- Smooth and fully exposed to a cleansing action
- Placed where dentist can finish them and patient can clean them
- Placed supra-gingival or gingival margin where poss
What are the reduction measurements for Metal crowns (full veneer gold crowns)?
Axial - 0.5mm
Occlusal functional cusps 1.5mm
Occlusal non functional cusps - 0.5mm
Finish line - Chamfer 0.5mm
What are the reduction measurements for Ceramic crowns (traditional porcelains)?
Axial - 1mm
Occlusal functional cusps - 1.5mm
Occlusal non-functional cusps - 1mm
Finish line - Shoulder 1mm
What are the reduction measurements for Metal ceramic crowns?
Axial - 1.3mm
Occlusal functional cusps - 1.8mm
Occlusal non functional cusps - 1.3mm
Finish line - Chamfer 0.5mm and Shoulder 1.3mm, 0.4mm metal, 0.9mm porcelain
What are the reduction measurements for all ceramic crowns?
Axial - 1.5mm
Occlusal functional cusps - 2mm
Occlusal non-functional cusps - 1.5mm
Finish line - Chamfer 1-1.5mm
Why should we replace teeth with bridgework?
- Aesthetics
- Occlusal stability (Prevent tilting and overeruption of adjacent and opposing teeth)
- Function
- Mastication
- Speech
- Wind instrument players
- Periodontal splinting
- Restoring occlusal vertical dimension
- Patient preference
Why would we not replace teeth with bridgework?
- Damage to tooth and pulp
- Secondary caries
- Effect on the periodontium
- Cost
- Failures
What are the different bridge designs?
- Cantilever
- Fixed-fixed
- Adhesive/Resin-bonded/Resin retained
- “Conventional”
- Hybrid
- Fixed-moveable
- Spring cantilever
What should you include in your informed consent to the patient?
- Verbal
- Written
- Invasiveness / reversibility
- Likely longevity and success rates (evidence based)
- Possible complications/consequences
- Time involved
- Costs
- Alternative options
What are some things patients may claim if you don’t give informed consent?
- Did not know what treatment was being provided
- Did not know the cost implications
- Received no warnings about the risks involved
- Was not aware of alterative options
- Did not give consent
