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.