Planning for Crowns and Bridges

Question 1

Define treatment planning

Answer 1

Logical sequence of treatment to restore the dentition to good health with optimal func and aesthetics

Question 2

What to inform the pt of regarding their TP?

Answer 2

Current conditions
Extent of dental tx proposed
Time and cost
Level of home care
Level of maintenance/repairs/replacements
Possible alterations
Informed consent

Question 3

What may the pt need regarding their tx?

Answer 3

Correct disease
Prevent future disease
Restore func
Improve appearance
Conform to pt needs

Question 4

Define crown

Answer 4

Indirect extracoronal restoration which replaces missiImpng tooth structure and restores anatomy

Question 5

Crown indications?

Answer 5

Badly broken down/previously heavily restored teeth
Trauma
Tooth wear
Hypoplastic conditions and typical shape
Alter and correct occlusion
Part of another restoration
Restore missing function
Appearance

Question 6

Crown contraindications?

Answer 6

More conservative restorative options viable
Poor OH
V broken down tooth with caries extending subginigvally
Periodontal condition - not enough bone support

Question 7

How to plan for crowns?

Answer 7

History and examination
Critical thinking and decision making - what is the best for the pt
Detailed planning of the crown and performing clinical and lab stages

Question 8

Features of pt history and examination for crowns?

Answer 8

Pt factors - compliance, expectations, age, understand limitations of procedure, complex procedure, social history, profession, habits, cost

Mouth condition - OH, status of other teeth, soft tissue conditions - mucosal reactions to dental materials

Tooth/teeth in question - value of tooth, position of tooth, appearance, pulp status, periodontium, occlusion, root length - bone support

Question 9

What to consider with young pts?

Answer 9

Size of pulp
Degree of eruption of teeth
Cooperation of pt

Question 10

Aesthetics in crowns?

Answer 10

Colour
Contour
Outline
Symmetry
Proportion
Soft tissue harmony

Question 11

Features of pulp status with crowns?

Answer 11

Check for vitality prior to crown prep (EPT, ethyl chloride)
15-20% of vital teeth will become non-vital following crown prep
Preop periapical radiograph
Assess size and depth of current restorations

Question 12

Features of occlusion with crowns?

Answer 12

Anterior teeth determine movement of posterior teeth
Failure to conform to, or correct anterior guidance upsets posterior occlusion
Understand and plan the occlusion

Question 13

Periodontal factors with crowns?

Answer 13

Correct and control inflam defects
Assess soft tissue contours
Correct if necessary:
- Ortho 
- Surgical

Question 14

Questions to ask before crowning?

Answer 14

Is it worth to be kept? Better extracted?
Suitable to be kept? Different restoration more suitable?
Remaining tooth sufficient for crown prep?
Will it need a restoration with a direct material first? - GIC, amalgam, composite
Pre-crown tx necessary - RCT?
Change occlusion?

Need for lengthening
Diagnostic waxup to help visualise result
Provisional restorations
Determination of best material?

Question 15

Types of crowns?

Answer 15

Full coverage crown
Partial coverage crown: 3/4
Post core crown

Question 16

Type of crown materials?

Answer 16

Gold or metal = good for posteriors as provides strength
Metal ceramic or porcelain fused to metal (PFM)
Dentine bonded crowns (ceramic)
High strength core all ceramic crown
Composite crown

Question 17

Define bridge

Answer 17

Bridge = tooth borne indirect fixed prosthetics used for the replacement of one or more missing teeth

Question 18

Indications for bridges?

Answer 18

Replacement of missing teeth and restoration of edentulous areas

Question 19

Reasons for tooth loss?

Answer 19

Caries
PD
Trauma
Hypodontia
Toothwear
Oral cancer
Iatrogenic

Question 20

Types of bridges?

Answer 20

Fixed-fixed = fixed both sides via abutments, pontic in middle
Fixed-moveable = in long stand bridges for flexibility
Cantilever = fixed from one end and free on the other
Resin bonded = pontic with wing
Implant retained = can be fixed fixed or cantilever

Question 21

Steps for bridge planning?

Answer 21

History and examination
Critical thinking and decision making
Detailed planning of the bridge and performing clinical and lab stages
Is the pt suitable for a bridge?

Question 22

What are the possible tx options for partially edentulous pts? Disadvantages?

Answer 22

No prosthetic tx: compromised func and aesthetics. Risk of tilting the adjacent teeth and over eruption of the opposing teeth

RPD: Conservative but removable option

Conventional tooth supported FPD: Invasive and irreversible approach, loss of enamel, pulp damage but fixed and predictable soln

Resin bonded bridge: Conservative fixed option but risk of debond and some aesthetic issues

Implant-supported FPD: Bone quantity and costs

Question 23

Clinical examination of bridges requires what?

Answer 23

Assessment of abutment teeth:

• Perio assessment
• Periapical abscess
• Root configuration; teeth with conical roots more suitable for short-span bridge

Radiographic exam to evaluate above

Length of span: how many missing teeth, fixed bridge more suitable than cantilever? Implant supported bridge?
Occlusion - sufficient intra-occlusal space?
Shape of ridge: ridge defect?
Surgical ridge augmentation?