Crown and bridges Flashcards
What does treatment planning inform the patient about?
Current conditions Extend of dental treatment proposed Time and cost Level of home care Level of maintenance/repairs/replacement
What does identification of patient’s needs involve?
Correction of existing disease Prevention of future disease Restoration of function Improvement of appearance should conform to the patient's needs
What are the available materials and techniques?
Plastic materials (amalgam and composite) Cast metal Porcelain Metal ceramic Veneered composite Fibre re-inforced composite CAD/CAM
What is the definition of a crown
an indirect extracoronal restoration which replaces tooth structure and restores anatomy
What are the indications for placing a crown?
Badly broken down or previously heavily restored teeth Trauma Tooth wear Hypoplastic conditions and atypical shape To alter occlusion Part of another restoration Restore missing function Mechanical problems Appearance
what are contraindications?
Other more conservative restorative option are viable
Poor oral hygiene
Very broken-down tooth with subgingival caries
Periodontal condition - not enough bone support
How do you carry out the history and examination for crown
Patient factors - age; younger have larger pulp, older more brittle teeth
Mouth condition
Tooth/teeth in question
What patient factors need to be considered in crown planning in young patients
Size of pulps
Degree of eruption of the tooth
co-operation of the patient
what are the general patient factors for crown planning
Attitude and expectation Co-operation Age Female patients - more concerned about appearance Social history, occupation Habits Cost
What are the individual tooth factors that need to be considered when crown planning
Value of the tooth Position of the tooth in the mouth Appearance Pulp status Periodontium Occlusion Root length
What are the 6 basic points of aesthetics
Colour Contour Outline Symmetry Proportion Soft tissue harmony
How would you assess the pulp status?
Always check vitality prior to crown prep
15-20% of vital teeth will become non-vital following crown prep
Always take a pre-op periapical radiograph
Assess size and depth of current restorations
Why is occlusion so important?
Anterior teeth determines the movement of the posterior teeth.
Failure to conform to, or create anterior guidance will upset posterior occlusion
Understanding and planning the occlusion is essential for success
What are the different types of crowns?
Gold or metal - posterior Metal ceramic or porcelain fused to metal (PFM) Dentine bonded crown (ceramic) High strength core all ceramic crown Composite crown
What is a bridge
Tooth-borne indirect prosthesis which is used for the replacement of one or more missing teeth
What are the reasons for tooth loss?
Caries Periodontal disease Trauma Hypodontia Tooth wear Oral cancer Iatrogenic
What are the different types of bridges
Fixed-fixed Fixed-movable Cantilever Resin bonded Implant retained
What are the steps for planning for bridges?
History and examination
Critical thinking and decision making
Detailed planning of the bridges and performing clinical and laboratory stages
(similar to crown planning )
What are the treatment options for partially edentulous patients
No prosthetic treatment - then have compromised function and aesthetics RPD Conventional tooth supported FPD Resin bonded bridge Implant supported FPD
What are the problems with conventional tooth supported FPD?
Invasive and irreversible approach
loss of enamel
Pulp damage but fixed and predictable solution, need to prepare the adjacent tooth
What is the problem with resin-bonded bridge?
Conservative fixed option but risk of debond and some aesthetic issues
How do you carry out a clinical examination
Assessing the abutment teeth Crown:root ratio Radiographic assessment Length of span Occlusion Shape of ridge
How do you assess the abutment teeth
Periodontal assessment
Periapical assessment
Root configuration
What is the max and minimum crown-root ratio
2: 3 optimum
1: 1 is the minimum
How should the occlusion be assessed?
the occlusion of the abutment tooth/teeth should be assessed but also the occlusion of pontic with the opposing arch should be predicted
How can the final appearance be predicted
use of study models and diagnostic wax ups
Temporary RPD
Reshaping of abutment teeth with composite and temporary attachment of pontic teeth
What are temporary lab-made bridges used for?
To predict outcome
Allow further modifications for aesthetic reasons
Allow modifications to occlusion
Give time to soft tissues to heal and reshape before final restoration
