Discolouration Flashcards
What should be included in pre-op records for all discoloured teeth?
- clinical photos
- shade
- sensibility testing
- diagram of defect
- radiographs (if clinically indicated)
- patient assessment
What are the treatent options for tooth discolouration?
- enamel microabrasion
- bleaching (vital, non-vital)
- resin infiltration (ICON)
- localised composite restoration
- composite venneers (direct, indirect)
- do nothing
What is microabrasion?
the removal of the surface layer of opaque enamel
What are the disadvantages of microabrasion?
- sensitivity
- more susceptible to staining
- prediction of treatment outcome difficult
- must be done in dental surgery
- cannot be delegated
What are the advantages of microabrasion?
- easily performed
- conserative
- inexpensive
- fast-acting
- removes yellow-brown, white and multi-ccoloured stains
- effective
- results are permanent
- can use before or after bleaching
Describe the clinical technique for microabrasion.
- PPE
- clean teeth with pumice and water
- soft tissue protection (petroleum jelly)
- rubber dam
- sodium bicarbonate guard
- HCL pumice slurry in slowly rotating rubber cup for 5 seconds
- wash directly into aspirator after every 5 sec application, review colour and shape
- maximum 10 of 5secs application
- fluoride varnish application (profluorid)
- polish with finest sandpaper disc
- final polish with toothpaste
Why is the tooth polished with sandpaper disc after microabrasion?
- compacted, relatively prismless layer of surface enamel
- changes the optical properties of the enamel
- intrinsic discolouration becomes less perceptible
How much enamel is lost when using prophy with toothpaste?
5-10 micron
How much enamel is lost when using prophy with pumice?
5-50 micron
How much enamel is lost when bonding/debonding orthodontic brackets?
5-50 micron
How much enamel is lost when acid etching?
10 micron
How much enamel is lost after 10 x 5 secs HCL pumice microabrasion?
100 micron
What proprietary kits are available for microabrasion?
- Opalustre (Ultradent)
- Prema Kit 10% HCl
What post-op instructions should be given after microabrasion?
- teeth are dehydrated after procedure
- warn patient to avoid highly coloured food and drinks for at least 24 hours
- review patient 4-6 weeks after microabrasion and take post-op photographs
What did GDC say about tooth whitening?
GDC 2014
Products containing or releasing between 0.1% and 6% hydrogen peroxide cannot be used on any person under 18 years of age except where such use is intended wholly for the purpose of treating or preventing disease.
This includes discolouration due to hypomineralisation, trauma, fluorosis, etc.
What whitening material is used for chairside bleaching?
unstable, rapidly reacting
hydrogen peroxide 15-38%
(equivalent to 75% carbamide peroxide)
What whitening material is used for home bleaching?
10% carbamide peroxide
What instructions should you give the patient when doing nightguard vital bleaching?
home bleaching
- brush teeth thoroughly
- apply a little gel to tray
- set over teeth and press down
- remove excess
- rinse gently, do not swallow
- wear overnight (or for at least 2 hours)
- remove tray and rinse with cold water
- sensitive toothpaste if required
What are the side effects of bleaching?
- tooth sensitivity in adults (15-65%)
- gingival irritation (more common in higher concentrations)
Why are teeth sensitive after bleaching?
easy passage of hydrogen peroxide through intact enamel and dentine and to the bleaching tray
What teeth are suitable for non-vital bleaching?
tooth selection
- adequate root filling (no clinical and radiological disease)
- anterior teeth without large restorations
- not amalgam intrinsic discolouration
- not fluorosis or tetracycline discolouration
What techniques are availables for non-vital bleaching?
walking bleach:
* oxidising process allowed to proceed gradually over days
inside-out method:
* 10% carbamide peroxide gel, can seal in if cooperation an issue
What is the clinical technique for non-vital bleaching?
- GP removed to below CEJ
- clean with ultrasonic
- bleachinng agent on cotton pledget
- cover with dry cotton pledget
- seal with GIC/RMGIC
How often are the appointments for non-vital walking bleach?
- renew bleach - ideally no more than 2 weeks between appointments
- if no change after 3-4 renewals, stop
- 6-10 changes total
regression 50% at 2-6 years
How would you restore a pulp chamber?
after RCT
- non-setting calcium hydroxide for 2 weeks, seal with GIC
- white GP and composite resin (facility to re-bleach)
OR
- non-setting calcium hydroxide for 2 weeks, seal with GIC
- incrementally cured composite (no re-bleaching, but stronger tooth)
if regression, restore tooth with veneer or crown
What are the complications of non-vital bleaching?
- external cervical resorption
- spillage of bleaching agents
- failure to bleach
- over bleach
- brittleness of tooth crown
How can external cervical resorption be prevented?
nv-bleaching
layer of cement over GP
* prevents bleaching agent from getting to external surface of root (not for inside-out technique)
* can prevent adequate bleaching of cervical area
non-setting calcium hydroxide in tooth for 2 weeks before final restoration
* reverses any acidity in PDL that might have occured
What are the effects of bleach on soft tissue?
short term and long term
Short-term exposure:
* minor ulceration/irritation
* plaque reduction
* aids wound healing
Long-term exposure:
* ? delayed wound healing
* ? periodontal harm
* ? mutagenic potential
What is resin infiltration?
infiltration of enamel lesions with low-viscosity light-curing resins
* surface layer is eroded, lesions desiccated and a resin infiltrant is applied
* resin pennetrates lesion driven by capillary forces
* infiltrated lesions lose their discoloured apperance and look similar to sound enamel
