Rest: Treating Discolouration Flashcards
EXTERNAL VITAL BLEACHING
Extrinsic causes for tooth discolouration ?
Smoking, tannins (tea, coffee, red wine), chromogenic bacteria, chlorhexidine, iron supplements.
EXTERNAL VITAL BLEACHING
Intrinsic causes for tooth discolouration ?
Fluorosis, tetracycline use in first year of life, non-vitality, physiological age changes, dental materials, medical conditions.
EXTERNAL VITAL BLEACHING
Name some medical condition which can cause tooth discolouration ?
Porphyria, cystic fibrosis, thalassemia, sickle cell anaemia, hyperbilirubinemia.
EXTERNAL VITAL BLEACHING
The active agent in vital external bleaching is hydrogen peroxide - how does it work ?
Forms acidic solution, breaks down into water and oxygen, hydroxyl free radical is formed (oxidising agent) which oxidises long chain organic molecules and breaks them into smaller non-pigmented ones.
EXTERNAL VITAL BLEACHING
What is the active agent in bleach ?
Carbamide peroxide - breaks down to produce hydrogen peroxide and urea (urea creates acidic environment and stabilised hydrogen peroxide).
EXTERNAL VITAL BLEACHING
What is the purpose of surfactant ?
Wets tooth surface.
EXTERNAL VITAL BLEACHING
What are the desensitising agents in bleach ?
Potassium nitrate and calcium phosphate and contains fluoride.
EXTERNAL VITAL BLEACHING
What is the function of carbopol ?
Thicknening agent.
EXTERNAL VITAL BLEACHING
What factors affect bleaching ?
Time, cleanliness of tooth, concentration, temperature.
EXTERNAL VITAL BLEACHING
What advice should you give to your patient regarding how long their sensitivity will last after treatment ?
2-3 days.
EXTERNAL VITAL BLEACHING
What will make a patient likely to experience sensitivity ?
Pre-existing sensitivity, gingival recession.
EXTERNAL VITAL BLEACHING
At home bleaching - what % of gel is prescribed to the patient ?
10-15% carbamide peroxide gel.
EXTERNAL VITAL BLEACHING
At home bleaching - what is the maximum strength of bleaching gel ?
16.7% carbamide peroxide = 6% hydrogen peroxide.
INTERNAL NON-VITAL BLEACHING
What are the indications for internal non-vital bleaching ?
Successful RCT, no PA pathology, non-vital tooth.
INTERNAL NON-VITAL BLEACHING
What are the contraindications for internal non-vital bleaching ?
Staining due to amalgam.
Heavily restored tooth.
INTERNAL NON-VITAL BLEACHING
What are the risks of internal non-vital bleaching that you should warn the patient of ?
External cervical root resorption due to diffusion of H2O2 through dentine/cementum into PD tissues - 1mm GP to be removed from pulp chamber.
Sensitivity.
INTERNAL NON-VITAL BLEACHING
Why should 1mm of RMGI be placed over the RCT after 1mm removal prior to internal bleaching ?
- Reduces risk of root resorption.
- Seals dentinal tubules.
- Prevents leaching of hydrogen peroxide into PD tissues.
INTERNAL NON-VITAL BLEACHING
What % of gel is used for internal non-vital bleaching ?
10% carbamide peroxide gel.
INTERNAL NON-VITAL BLEACHING
How often should internal bleaching be carried out and at what intervals ?
3-4 times at weekly intervals.
Should be repeated every 4-5 years.
MICRO-ABRASION
What are the indications for micro-abrasion ?
Fluorosis, post-orthodontic demineralisation, demineralisation with staining, prior to veneering if dark staining is present.
PAEDATRICS TREATMENT OF INTRINSIC DISCOLOURATION
What special investigations would you carry out prior to planning treatment for discolouration ?
Clinical images, shade, sensibility testing, diagram of defect, radiographs if indicated.
PAEDATRICS TREATMENT OF INTRINSIC DISCOLOURATION
What are the treatment options for treating intrinsic discolouration ?
Enamel microabrasion.
Bleaching.
Resin infiltration.
Localised composite restoration.
Veneers - lab or composite.
Nothing.
PAEDATRICS TREATMENT OF INTRINSIC DISCOLOURATION
Define microabrasion.
Removal of surface layer of opaque enamel.
PAEDATRICS TREATMENT OF INTRINSIC DISCOLOURATION
What are the advantages of microabrasion ?
Easy, conservative, inexpensive, minimal subsequent maintainance, fast acting, removes all stains, effective, permanent results.
PAEDATRICS TREATMENT OF INTRINSIC DISCOLOURATION
What are the disadvantages of microabrasion ?
Removes enamel, sensitivity, more suseptible to staining, requires protective apparatus, difficult to predict outcome, done in dental surgery, cannot be delegated.
PAEDATRICS TREATMENT OF INTRINSIC DISCOLOURATION
What protective equipment should you use for a patient when carrying about acid microabrasion ?
PPE - patient and operators.
Soft tissue vaseline.
Sodium bicarbonate guard.
Rubber dam.
Clean teeth with pumice and water.
Sodium bicarbonate available.
PAEDATRICS TREATMENT OF INTRINSIC DISCOLOURATION
Describe microabrasion technique.
- Clean and dry teeth.
- HCl pumice slurry in rubber cup for 5 seconds with sodium bicarb behind teeth.
- 10 x 5 second applications - max.
- Wash directly into aspirator.
- Review colour.
- Fluoride varnish (Profluorid).
- Polish with finest sandpaper.
- Polish with toothpaste.
PAEDATRICS TREATMENT OF INTRINSIC DISCOLOURATION
What is the maximum applications of microabrasion (HCl pumice) ?
10 x 5 second applications.
PAEDATRICS TREATMENT OF INTRINSIC DISCOLOURATION
Why are teeth polished with finest disc after microabrasion ?
SEM shows compacted, relatively prismless layer of surface enamel after microabrasion so this changes optical properies of enamel so that areas of intrinsic discolouration become less perceptible.
PAEDATRICS TREATMENT OF INTRINSIC DISCOLOURATION
How many microns of enamel surface is lost after microabrasion treatment vs. toothpaste ?
100 microns.
5-10 microns with toothpaste.
PAEDATRICS TREATMENT OF INTRINSIC DISCOLOURATION
What % of HCl pumice do proprietary kits used for microabrasion ?
Opalustre 6.6%
Prema Kit 10%
PAEDATRICS TREATMENT OF INTRINSIC DISCOLOURATION
What post-op advice should be given following microabrasion ?
Avoid highly coloured foods and drinks for at least 24 hours.
PAEDATRICS TREATMENT OF INTRINSIC DISCOLOURATION
When should a patient be reviewed following microabrasion ?
4-6 weeks and take post-op photos.
PAEDATRICS TREATMENT OF INTRINSIC DISCOLOURATION
How many cycles of HCl pumice microabrasion can you undertake ?
2
PAEDATRICS TREATMENT OF INTRINSIC DISCOLOURATION
How do you prevent external cervical root resorption due to internal bleaching ?
GI over GP.
Non-setting CaOH 2 weeks before final restoration - reverses acidity in PDL.
PAEDATRICS TREATMENT OF INTRINSIC DISCOLOURATION
Describe resin infiltration.
Infiltration of enamel lesions with low-viscosity light-cure resins - resin penetrates through capillary forces and corrects discolouration to same refractive index as enamel.
PAEDATRICS TREATMENT OF INTRINSIC DISCOLOURATION
What are the two indications for resin infiltration ?
Decal and MIH.