Tooth Whitening Flashcards
What regulation was implemented to aid with tooth whitening?
EU cosmetics regulation
What did the EU cosmetics regulation bring about?
Illegal to contain more than 6% hydrogen peroxide
Substances with 0.1-6% sodium peroxide should not be made directly available to consumer
What does GDC state about tooth whitening products?
Only sold to practitioners and first use can only be carried out by practitioners or under direct supervision
Not use over 6%
Causes of tooth discolouration?
Smoking
Red wine
Tea and coffee
Bacteria
Chlorhexadine
Iron supplement
Two types of tooth bleaching?
External vital bleaching
Internal non-vital bleaching
What is vital external bleaching?
Bleaching oxidises high molecular weight organic molecules within tooth substance
Causes ionic exchange leading to lighter colour
What active agent is used in vital external bleaching?
H2O2
Mixed with water producing free radical of HO2 which is oxidising agent
What ingredient is broken down to produce the H2O2?
Carbamide peroxide
Breaks down to form H2O2 and urea
10% carbamide gives 2.6% H2O2
What ingredient increases the viscosity of material in vital external bleaching?
Carbopol
Thickening agent to keep the material on the tooth or in the tray
Advantages of in office bleaching
Dentist controlled
Heat and light
Quicker results
Disadvantages of in office bleaching
Time for dentist
Uncomfortable
Results wear off quicker
Expensive
Technique of in office bleaching
Cleaning of teeth
Rubber dam or gingival mask
Apply bleaching gel and heat / light
Wash dry and repeat
30 mins - 1 hour
How is home vital bleaching done?
10-15% carbamide peroxide gel equating to 6% H2O2
Custom made tray and gels at home
Bleaches slowly over several weeks
How does dentist set up home bleaching?
Alginate impressions and then acrylic vacuum formed splint made that stops 1mm short of gingival margin and has buccal spacer
Full mouth cleaning in surgery and check trays
Give instructions
Load tray at home 1mm dot buccal on each tooth
Place tray in for 2 hours or overnight
When should one bleach
Age related bleaching
Mild fluorosis
Post smoking cessation - dont bleach a smoker
Possible issued with bleaching?
Sensitivity is large one
- normally resolves over 2-3 days
- pre-existing sensitivity or high bleach conc can increase risk
Possible irritation of the gingiva
Composite does not bleach but teeth do!
Causes of non-vital tooth discolouration
Pulp canal obliteration
Pulp bleeding into dentine
Non vital tooth
Indications for non vital internal bleaching?
Non vital tooth
Adequate RCT
Contra indications for internal non vital bleaching
Heavily restored tooth
Amalgam staining in tooth
Risks of internal bleaching?
External cervical resorption
Due to diffusion of H2O2 through dentine into periodontal tissues
Technique for internal bleaching?
Record shade
Prophylaxis
Rubber dam
Remove filling from access cavity
Remove GP from pulp chamber and 1mm below ACJ
Place 1mm RMGIC over gp to seal canal
Remove dark dentine
Etch internal surface with phosphoric acid
Place 10\5 carbamide peroxide gel topped with cotton wool
Seal with GIC
Repeat weekly intervals until shade required or no change
Restore palatal cavity with white GP in pulp chamber and light shade composite
What is micro abrasion?
Removes discolouration of enamel on outer layers only
Using 18% HCL and pumice
What is resin infiltration?
Treats white spot lesions on teeth
Resin impregnates the porous enamel area and masks it to look like normal enamel
What must be done prior to tooth whitening
Proper medical examination and history to ensure patient is ok for bleaching of teeth
What are some medical contraindications
Glucose 6 phosphate dehydrogenase deficiency
Acatalasemia
Neither group can metabolise hydrogen peroxide
Aged under 18 - can only be used solely for preventing disease, not aesthetics
