Management of approximal caries Flashcards
Why is approximate caries common?
Contact point of tooth is a nice stagnation point for bacteria
At what point does approximal caries need restoration?
When the lesion reaches the ADJ
On occlusal surfaces what is the most common restoration? Why is this not the same for approximal?
PRR and FS over the top
Approximal is harder to get to
What factors are necessary for a good clinical examination to diagnose approximal caries?
Clean, dry, good lighting
What probe is used to test the hardness of the enamel in a suspected lesion?
Briault/straight probe
What is transillumination?
When is it useful?
Reflecting operating light through contact point. This is useful for posterior teeth.
The bright light will make the caries appear darker
What technique is particularly useful for viewing approximal caries?
Seperators
What types of radiographs are useful for diagnosing approximal caries?
Bitewiing, DPTs, periapical
How does approximal caries spread?
In a vertical line, simultaneously pulpward
Name 5 problems with radiographs for diagnosis.
Cervical burn-out = area of black between and enamel and bone, looking like caries
Contrast (over/under-exposure)
Restorations (lesions may be beneath or hidden by restorations)
Problems if bean angulation is wrong
Superimposition
How can you tell the difference between cervical burn-out and caries?
Burn out will be more triangular shape and closer to the bone, it will affect equal number of teeth on the X-ray, not just one.
Caries will be more rounded with no defined border, it will spread into enamel nd subgingivally
How long does approximal caries take to reach dentine in permanent teeth?
3-4 years, in a reversible cycle of demineralisation and remineralisation
Name and explain 4 ways approximal caries can be prevented?
Eliminate carbohydrate substrate (dietary analysis and advice)
Increase resistance of host (fluoride)
Eliminate bacterial plaque (inter proximal cleaning techniques)
Diet diary (define the problem)
Name 4 aims of operative treatment
Remove bacterial infection
Reinforce the remaining tooth structure
Restore function and aesthetics
Protect the pulp from bacterial invasion
Name the 3 steps that come before designing a cavity?
Gain access to caries Remove caries (clear periphery at ADJ) Put instruments down --> Look, think, design
What 5 things must you think about during ‘look, think, design’ of a cavity?
Choice of material
Retention of material
Features to protect the remaining tooth structure
Features to maximise strength of the tooth and restoration
Shape and position of the cavity margins
What are the 3 types of materials that can be used for designing a cavity?
Direct e.g. amalgam, composite, glass ionomer
Indirect e.g. inlet/onlay
Combination
What 5 factors affect the retention of the material?
Grooves Undercuts Dovetails (pins) Dentine bonding Physical and chemical bonds
What features of a cavity protect the remaining tooth structure?
Removing unsupported enamel
Modify weak cusps
Occlusal coverage
Splinting with adhesive materials
What features of a cavity maximise strength of the tooth and restoration?
Adequate thickness of material
Ensure sufficient tooth is left
Tissue has been removed
Shape and position of cavity margins
a) amalgam and porcelain
b) composite
c) position in relation to gum
d) contact area between teeth
e) margins on anterior sites
a) 90-degree margin
b) bevelled margin
c) supragingival
d) clear contact area
e) left intact to improve aesthetics
Name 3 ways approximal caries can be accessed
Occlusally
Buccal/lingually
Directly
How is approximal caries accessed occlusally?
Through the marginal ridge - always try to preserve after but if too little is left it will just break so remove
When can approximal caries be accessed directly?
When there is adjacent tooth loss
Why try to preserve marginal ridge?
Removing reduces strength of tooth by 69%
What are the limitations of dental amalgam?
Not used in children under 15/pregnant/breastfeeding
Destructive preparations
Differences and similarities between posterior amalgam vs composite preparations
Composite -> access caries sousing larger, slower speed burr
Both - remove caries at ADJ
Amalgam –> at this point consider retention factors e.g. make groove
Composite –> remove surface contaminants , etch, bond and restore
Amalgam –> insert metal matrix band and insert amalgam
