Tooth whitening Flashcards
Causes of discoloration
Caused by formation of chem. stable chromogenic products in tooth substance
Extrinsic
-Smoking
-Tannins
-Tea
-Coffee
-Red Wine
-Guinness
-Chromogenic Bacteria
-Chlorhexidine
-Iron supplements
Intrinsic
-Fluorosis
-Tetracycline
-Non-vitality (blood products)
-Physiological (age changes)
-Dental Materials
-Amalgam
-Root filling materials
-Porphyria (red primary teeth)
-Cystic Fibrosis (grey teeth)
-Thalassemia, Sickle Cell anaemia (blue, green or brown teeth)
-Hyperbilirubinaemia (green teeth)
What should first method of tooth whitening for extrinsic staining be
PMPr and polish
What are the types of bleaching
External Vital Bleaching
Internal Non-vital bleaching
Talk about external vital bleaching
Oxidisies componds in stain leading to smaller molecules not pigmented
Oxidation can cause ionic exchange in metallic molecules leading to lighter colour
Hydrogen peroxide is the active agent
-Forms an acidic solution in water
Breaks down to form water and oxygen
-Free radical per hydroxyl (HO2)is formed. This is the active oxidising agent
What are the consituents of Vital External Bleaching
Carbamide peroxide
Carbopol (thickening agent)
Urea (Raises pH
Stabilises Hydrogen Peroxide)
Surfactant (Allows the gel to wet the tooth surface)
Pigment dispersers
Preservative
Flavour
Potassium Nitrate
Calcium Phosphate
Fluoride
What factors affect external vital bleaching
time
cleanliness of tooth
conc. of solution
Temp. higher=quicker
What should you make sure with bleaching and what warnings do you give
check patient is dentally fit
Warnings for patient:
Sensitivity
Relapse
Restoration colour
Allergy
Might not work
Compliance with regime
What are the 2 types of vital external bleaching
Chair-side/In-office
Home
Adv and DisAdv of chair side
Adv:
your in cahrge
Can use heat/light
Quick results
Disadvantages:
Time for dentist
Can be uncomfortable
Results tend to wear off quicker
Expensive
Whats the chair side technique
Thorough cleaning of teeth
Ideally rubber dam
At least gingival mask
Apply bleaching gel to tooth
Apply heat/light
Wash/dry/repeat
Whats vital
Gingival mask for protection of the gingivae
What is home external vital bleaching
Much the commonest technique
10%-15% Carbamide Peroxide Gel
Patient uses solution at home
Custom made tray
Bleaches slowly, over several weeks
Easy for dentist and patient
Whats the at home technique
In Surgery
-Full mouth cleaning/polishing of teeth in surgery
-Fit trays and check extension/comfort
-Instruction in use
At Home
-Brush and floss teeth
-Load tray 1mm2 dot buccally on each tooth
-Fit tray in mouth, Requires to be in place for at least 2 hrs
Preferably overnight
Review at 1 week:
Most patient see a result within 2 – 3 days
Normally reached maximum by 3 – 4 weeks
When to do bleach (External)
Age related darkening/discolouration(yellow/orange discolouration respond better)
Mild fluorosis
Post smoking cessation
Tetracyclin staining
What are common bleaching problems
Sensitivity (Resolves over 2-3 days post bleaching)
Wears off
Cytotoxicity/Mutagenicity
Gingival irritation
Tooth damage
Damage to restorations
Problems with bonding to tooth
Do you use chlorine dioxide
NEVER
What are the indications of internal bleaching
Indications
Non-vital tooth
Adequate RCT
No apical path
What are the contraindications of internal bleaching
Heavily restored tooth
Better with crown or veneer
Staining due to amalgam
Limitations
Doesn’t always work but generally worth a go
at are Adv and risks of internal bleaching
Advantages
-Easy
-Conservative
-Patient satisfaction
Risks
-External Cervical resorption
Whats the internal whitening tech.
-Record shade
-Prophylaxis
-Rubber dam
-Remove filling from access cavity
-Remove GP from pulp chamber and 1mm below amelo-cemental junction
-Place 1mm RMGIC over GP to seal canal,Seals dentine and prevents root resorption
-Remove any very dark dentine
-Etch the internal surface of the tooth with 37% phosphoric acid
-Place 10% carbamide peroxide gel in cavity
-Cotton wool over this
-Seal with GIC
-Repeat procedure at weekly interval
-Repeat until,Required shade achieved,No change
Normally takes 3 – 4 visits
-Once final shade obtained restore the palatal cavity
-Place white GP or similar in pulp chamber
-Restore with light shade of composite
-Will gradually darken again
Retreatment every 4 – 5 years
What is microabrasion and its indications
Removes discolouration limited to the outer layers of enamel
Combination of erosion (acid) and abrasion (pumice)
Fluorosis
Post orthodontic demineralisation
Demineralisation with staining
Prior to veneering if dark staining is prese
Tech. of abrasion
-Clean teeth thoroughly
-Rubber dam (seal is very important)
-Mix 18% HCl and pumice
-Apply to teeth
-Gently rub with prophy cup 5 seconds/tooth
-Wash
-Repeat up to 10X
-Remove rubber dam
-Polish teeth with fluoride prophy paste
-Apply fluoride gel or varnish, fluoride to help reharden the surface and decrease sensitivity
-Review after one month
AD and DisAdv of microabrasion
Advantages
Quick
Easy
No long term problems
Pulpal damage
caries
Disadvantages
Acid
Sensitivity
Only works for superficial staining
Works much better for brown staining than white marks
What is whitening classed as and why
Cosmetic
The Cosmetic Products (Safety Amendment) Regulations 2012 (implementing Directive 2011/84 EU which amends directive 76/768/EEC) came into force in October 2012
What are the contradictions to whitening
Very rare
Glucose-6-Phosphate dehydrogenase deficiency
Acatalasemia
What are the medico legal issues
it is illegal for tooth whitening products which contain more than 6% hydrogen peroxide
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 preventing disease
tooth whitening products containing or releasing between 0.1%-6% hydrogen peroxide should not be made directly available to the consumer, other than through treatment by a registered dentist
Whitening products can only be sold by dental practitioners
The first cycle of treatment must be supervised
