1 - Discolouration Flashcards
What are the broad treatment options for discolouration?
- enamel microabrasion
- bleaching
- resin infiltration
- localised composite restoration
- veneers
What pre-op records are required for discoloured teeth?
- clinical photos
- shade
- sensibility testing
- can also take radiographs, defect diagram, patient self-assessment
Describe the HCl pumice microabrasion technique.
- vaseline to gingivae, rubber dam placed and sodium bicarbonate guard
- HCl pumice slurry in slowly rotating rubber cup for 10s x 5 on each tooth
- wash tooth into aspirator between each pumice
- polish with sandpaper disc
- apply fluoride varnish
- polish with toothpaste
What fluoride varnish is recommended for HCl pumice microabrasion?
- profluorid
- duraphat is yellow in colour and can stain teeth
What concentration of HCl is used for microabrasion?
18%
What is the purpose of the sodium bicarbonate guard?
To neutralise the acid and prevent damage to the rubber dam and injury to the patient
What is the purpose of polishing with sandpaper discs?
- changes the optical properties of the enamel prisms
- areas of intrinsic discolouration become less perceptible
How much enamel is removed using microabrasion?
100 microns
What are the advantages of microabrasion?
- conservative
- inexpensive
- minimal maintenance
- fast acting
- removes yellow/brown/white stains
- effective
- results are permanent
- can be used alongside bleaching
What are the disadvantages of microabrasion?
- removes enamel
- HCl is caustic
- requires PPE
- prediction of outcome is difficult
- must be done chair side
- cannot be delegated
What POI are important after microabrasion?
- avoid highly coloured food and drink for 24-48 hours
- “anything that would stain a white t-shirt”
When should you review a microabrasion treatment?
- 4-6 weeks with post-op photos
- teeth are dehydrated after procedure so final result may differ
What is the legislation surrounding bleaching in children?
Bleaching with hydrogen peroxide is not allowed in U18s except for the use which is wholly intended for the purpose of treating or preventing disease
What are the different types of bleaching?
- vital bleaching
- non-vital bleaching
What are the different types of vital bleaching?
- power bleaching (chairside)
- night guard bleaching
What are the different types of non-vital bleaching?
- inside outside technique
- walking bleach technique
What chemical is used for chairside power bleaching?
Fast acting 15-38% hydrogen peroxide
What chemical is used for night guard bleaching?
10% carbamide peroxide
How long does night guard bleaching take to get a desired result?
3-6 weeks
What is the breakdown of carbamide peroxide?
- 10% carbamide peroxide
- 3% hydrogen peroxide, 7% urea
- water, ammonia and CO2
What are the advantages of non-vital bleaching?
- conservative
- original tooth morphology
- gingival tissues are not irritated by a restoration
- adolescent gingival margin is not a restorative consideration
- no laboratory involvement
What is the selection criteria for non-vital bleaching?
- adequate root filing with no clinical or radiographic disease
- anterior tooth without large restoration
- no amalgam intrinsic discolouration
- discolouration is not due to fluorosis or tetracycline
Describe the preparation for “walking” non-vital bleaching.
- GP removed below gingival margin
- cotton wool pellet soaked with bleaching agent placed in cavity
- dry cotton wool pellet to cover
- sealed with GIC
What is the frequency of appointments for walking bleach?
- renew bleach every 2 weeks
- 6-10 changes total
Describe the preparation for combination non-vital bleaching.
- access cavity
- remove GP below gingival margin
- GI lining
- custom made trays given to patient and bleaching agent
What instructions should be given to patients using combination non-vital bleaching?
- ensure cavity is kept clean
- apply bleaching agent to back of tooth and in tray
- gel changed every 2 hours except during night
- to wear trays at all times except eating and cleaning
Describe the restoration of the pulp chamber after non-vital bleaching.
- non-setting CaOH for 2 weeks to reverse acidity of chamber
- either, white GP and composite (facilitate re-bleach)
- or, incrementally cured composite (no re-bleach)
What are the potential complications of non-vital bleaching?
- external cervical resorption (more common in traumatised teeth)
- spillage of bleaching agents
- failure to bleach
- over bleach
- brittle crown
What is the indication for tooth mousse after bleaching?
- sensitivity
- prevention
What contraindicates the use of tooth mousse?
- dairy allergy
- religious views
Describe the process of resin infiltration.
- surface eroded
- lesions desiccated
- resin infiltrant applied
What causes the resin to infiltrate the enamel?
Capillary forces due to the lesion being desiccated
What causes the change in discolouration using resin infiltration?
Resin changes refractive index of enamel
What should you warn patients of before resin infiltration?
- takes away white lesions, to appear more like background enamel
- can be used in conjunction with bleaching but resin may block enamel prisms and prevent uniform bleach
What method of treating discolouration is recommended for tetracycline staining?
- composite veneers
- will not respond to other methods
Why are veneers contraindicated in younger patients?
- gingival margin level does not finalise until early 20s
- restoration margin may become visible as level finalises
