Treatment Planning for Fixed Prosthodontics Flashcards
What are the types of indirect restoration?
Veneers
Inlays and Onlays
Crowns
Post and cores
Bridgework
What is included in the history and exam that provides a provisional diagnosis?
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)
What are the extra-oral sites to be examined?
TMJ
Muscles of mastication (MoM)
Lymph nodes
Symmetry
Lips (vermillion border, commissures, smile line)
What are the intra-oral sites to be examined?
Soft tissues
Buccal mucosa
Tongue
Lateral borders
Dorsum
Sublingual tissues/Floor of mouth
Palate
Hard
Soft
Lips
What other exams do you do during the intial exam?
Periodontal
BPE
Dentition
Chart teeth
Present and missing teeth
Restorations
Caries
Occlusion
Incisal relationship
Excursions of the mandible
Protrusion
Retrusion
Lateral
Canine guidance?
Group function?
Inter-arch space
Inter-tooth space (mesio-distal)
What are the special investigations?
Radiographs
Sensibility tests
Study models
Facebow
Diagnostic wax-up
Diet diary
Plaque indices
6PPC
Clinical photographs
Microbiology, Biopsy, Haematology
What radiographs should you take if the patient is edentulous?
periapical
What does a facebow measure?
measures relationship between hinge axis of TMJ and maxilla relationship
What part of treatment planning should fixed prosthodontics be?
reconstructive
What are the steps of treatment planning?
immediate
intial (disease control)
re-evaluation
reconstructive
maintenance
What are alternative options to fixed pros?
extract tooth
removable pros
implant
Why 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 technique is used for planning veneers?
gurel minimal prep technique
Wax up
Stent
Intra-oral mock up
Preparation into mock up (can use depth cut burs)
When should veneers not be an option?
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?
Toothwear cases
Increase OVD
Fractured cusps
Restoration of root treated teeth Onlays provide cuspal coverage
Replace failed direct restorations
Minor bridge retainers (not recommended)
When would you 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 conventional bridgework
When indicated by the design of a RPD
Rest seats
Clasps
Guide planes
To restore tooth function e.g.restore in OVD
Why 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 prep?
- Preservation of tooth structure
- Retention and resistance
- Structural durability
- Marginal integrity
- Preservation of the periodontium
- Aesthetic considerations
What does under-prep result in?
Poor aesthetics
“Over built” crown with periodontal and occlusal consequences
Restorations with insufficient thickness
What does over-prep result in?
Pulp and tooth strength being compromised
What is retention?
Prevents removal of the restoration along the path of insertion or the long axis of the tooth preparation
What is resistance?
Prevents dislodgement of the restoration by forces directed in an apical or oblique direction and prevents any movement of the restoration under occlusal forces
What aspects of the prep of crowns determines retention and resistance?
Taper: Ideal inclination of opposing walls 6-10o.
Length of the walls
Path of insertion
Extra means of retention (Grooves, Slots)
What do longer walls mean?
reduced tipping displacement
What is the path of insertion?
Imaginary line along which the restoration will be place onto or removed from the preparation.
Is set before the preparation is begun and all the features of the preparation must coincide with that line.
What does limiting the paths of insertion do?
improve retention
What aspects of design acheive structural durability?
Occlusal reduction
Functional cusp bevel
Axial reduction
What are the 5 finish line configurations for the margins?
(a) Knife edge
(b) Bevel
(c) Chamfer
(d) Shoulder
(e) Bevelled shoulder
What finish line is used for metal/procelin crowns?
chamfer
What finish line is used for ceramic/metal crowns?
shoulder
What should the margins of the restoration be?
- Smooth and fully exposed to a cleansing action.
- Placed where the dentist can finish them and the patient can clean them.
- Placed supra-gingival or at gingival margin whenever possible.
Why not replace teeth?
Damage to tooth and pulp Secondary caries
Effect on the periodontium Cost
Failures
What are the two shapes for bridge designs?
cantilever
fixed-fixed
What should you communicate with the patient?
Invasiveness / reversibility
Likely longevity and success rates (evidence based)
Possible complications
Time involved
Costs
Alternative options
What should patients be informed for consent?
What treatment is to be performed
Why it is necessary
Consequences of not having treatment
What risks may be involved (material risks)
What alternatives are there (and their risks)
Relative costs
