Extrinsic and intrinsic causes of tooth discolouration
Intrinsic
- smoking
- tea, coffee, red wine, Guinness
- chromogenic bacteria
- iron supplements
Extrinsic
- fluorosis
- non vitality
- Physiological (age change)
- injury - pulp obliteration
- materials - amalgam /root filling
- cystic fibrosis (grey)
- sickle cell anaemia
What are the two types of bleaching teeth
Intrinsic (non vital)
Extrinsic (vital or non vital)
External tooth bleaching
- what used
- how has effect
How:
- hydrogen peroxide 6% MAX but normally 3.6% (H2O2)
- carbamide peroxide 10% which actually breaks down to make 3.6% (16% carbamide peroxide = 6%)
- chemically stable, chromogenic products within tubules (long chain organic molecules
- bleaching oxidises these into non pigmented smaller molecules
- also oxidation = ionic change in metallic molecules meaning lighter colour
Constituents of material used for external bleaching of teeth
Bleaching gel
1. Carbamide peroxide 10% (makes h2o2)
- Carbopol (thickening agent, makes stay on surface and slow diffusion)
- Urea (raises ph, stabilises h2o2)
- Surfactant (let’s gel wet tooth)
- Pigment dispersers
- Preservative
- Flavour
- Fluoride (prevents erosion)
- Potassium nitrate and Calcium phosphate (tooth desensitising agents)
Factors effecting efficient of bleaching
- Time
- Cleanliness of surface
- Conc.
- Temp
Adv / negatives of in office tooth bleaching
Technique
How long for
Does heat / light / laser effect bleaching of teeth
Home vital bleaching of teeth info
10-15% carbamide peroxide prescribed by dentist and 0.5mm acrylic sport splint
1mm squared on each tooth buccal on splint and wear for at least 2 hrs once a day (preferably do at night sleeping)
Should see results in 2-3 (max at 3-4) days and review in a week, if no effect by then then won’t work
What to never use for tooth whitening
Chlorine dioxide as softens and strips enamel
Sensitivity issues with tooth bleaching
And bonding issues
Contraindications / adv / negatives of internal bleaching
Contraindications / adv / negatives of internal bleaching
Technique for internal bleaching
Why place RMGI
- Remove pump chamber filling and flight part of GP and cover with 1mm RMGI to make flush and full access to entire pulp chamber AND stops getting into root and then diffuse to PDL and damage
- Remove any dark dentine
- 37% phosphoric acid etch internal surface then place 10% carbamide peroxide in cavity and cotton wool then seal with GIC
- Repeat weekly for up to 4 visits and if not better after this won’t work
- Fill pulp cavity with white GP, then restore with composite
- Gradually darker over time and re do in 4-5 years
What is combination bleaching
Wear tray whole time as hole and gel replace frequently for a week (reservoir on palatal side rather than buccal of tray for this)
What is the micro abrasion technique in tooth whitening
Indications for
Technique
Advantages/disadvantages
18% HCL and pumice mixed and prophy cup used for 5 secs per tooth to sand down with abrasion and erosion
What is the micro abrasion technique in tooth whitening
Indications for
Technique
Advantages/disadvantages
18% HCL and pumice mixed and prophy cup used for 5 secs per tooth to sand down with abrasion and erosion
What is resin infiltration in terms of fixing the aesthetics of teeth
Anaesthetics and max doses
Lidocaine 2% 1:80,000
- 4.4mg kg (1 cartridge per kg) - as one cartridge is 2.2ml
- 44mg in a cartridge
Prilocain 3% with fiepressin
- 8mg / kg
- 66mg in cartridge
Articain 4%
- 7mg /kg
88mg in cartridge
Minimum UKELD SCORE for liver transplant
49 - lower = worse and this is the cut off
When best to do to for a dialysis to
24hrs after dialysis but not close to next dialysis
