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teeth whitening lecture
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COLOUR
Teeth made of many colours, with natural gradation from the darker cervical to the lighter incisal third
Variation affected by thickness of enamel and dentine, and reflectance of different colours
Blue, green and pink tints in enamel, yellow through to brown shades of dentine beneath
Canine teeth darker than lateral incisors Teeth become darker with age
(secondary/tertiary dentine, tooth wear/dentine exposure)
COLOUR
Tooth colour affected by:
individual interpretation time of day patient positioning/ angle tooth is viewed at hydration of tooth (always take shade at start
of appointment) skin tone (make-up) surrounding conditions (e.g. lighting in clinic)
AETIOLOGY OF DISCOLOURATION
Extrinsic Discolouration: Stains (chromogens) that lies on/attach to the
tooth surface or in the acquired pellicle, or The incorporation of extrinsic stain within the
tooth substance following dental development. It occurs in enamel defects and in the porous surface of exposed dentine (‘stain internalisation’).
Extrinsic Discolouration:
E.g.•Plaque, chromogenenic bacteria•Mouthwashes (chlorhexidine)
•Smoking / chewing tobacco•Beverages (tea, coffee, red wine, cola)•Foods (curry, cooking oils and fried foods, foods with colorings, berries, beetroot)
• Antibiotics (erythromycin, amoxicillin-clavulanic acid)• Iron supplements
AETIOLOGY OF DISCOLOURATION
AETIOLOGY OF DISCOLOURATION
Intrinsic Discolouration: Intrinsic discolouration occurs following a change to the structural composition or thickness of the dental hard tissues.
Pre-eruptive:
Disease:•Haematological diseases•Liver diseases•Diseases of enamel and dentine (e.g. Amelogenesis/ Dentinogenesis imperfecta)
Medication:•Tetracycline, other antibiotic s
Fluorosis stains (excess F)Enamel hypoplasia (trauma or infection)
Post-eruptive:Trauma (e.g. pulpal haemorrhagic products)Primary and secondary cariesTooth wearDental restorative materialsAgeingChemicalsAntibiotics
Minocycline (used to treat acne)
Intrinsic Discolouration:
AETIOLOGY OF DISCOLOURATION
Types of Discoloration Colour Produced
Extrinsic (Direct stains)
Tea, coffee and other foods
Cigarettes/cigars
Plaque/poor oral hygiene
Brown to black
Yellow/brown to black
Yellow/brown
Extrinsic (Indirect stains)
Polyvalent metal salts and cationic antiseptics
e.g. Chlorhexidine
Black and brown
Intrinsic
(Metabolic causes)
e.g. Congenital erythropoietic porphyria
(Inherited causes)
e.g. Amelogenesis Imperfecta
e.g. Dentinogenesis Imperfecta
(Iatrogenic causes)
Tetracycline
Minocycline
Fluorosis
(Traumatic causes)
Enamel hypoplasia
Pulpal haemorrhage products
Root resorption
(Ageing causes)
Purple/brown
Brown or black
Blue-brown (opalescent)
Banding appearance:
classically yellow, brown, blue, black or grey
Grey
White, yellow, grey or black
Brown
Grey black
Pink spot
Yellow
Internalized
Caries
Restorations
Orange to brown
Brown, grey, black
MANAGEMENT OF DISCOLOURED TEETH
Treatment options:
1.No treatment
2.Removal of surface stain
3.Bleaching techniques
4.Operative techniques to mask underlying discolouration Veneers Crowns
Treatment option Indications Advantages Disadvantages
No treatment Patient with poor oral hygiene/ caries/ PA pathology, large ant restorations/crowns
Non invasive, no cost Will not address patients aesthetic concerns
Removal of surface stain
-Scale and polish
-Microabrasion-Extrinsic staining
-Fluorosis, white spot demineralisation, enamel hypoplasia
Non/minimally invasive May not improve aesthetics significantly, may require further Rx
Microabrasion- soft tissue irritation/ excessive tooth prep (technique sensitive)
Bleaching
-Home bleaching, Walking bleach
-See later slides
Non/minimally invasive Cost, limitation on shade improvement (a few shade lighter only), may fail/ need repeating, compliance (home bleaching)
Restorative treatment
-Veneers, crowns
Severely discoloured teeth, e.g. tetracycline staining (may bleach 1st)
Unaesthetic tooth morphology (e.g. AI/DI)
Heavily restored teeth
May achieve a more aesthetic result
Destructive, irreversible (tooth tissue removal), changes natural shape of teeth, cost, maintenance, oral hygiene compliance (interdental cleaning)
GENERAL INDICATIONS
Generalised staining Ageing Extrinsic stain - Smoking and dietary stains
(tea/coffee etc) Fluorosis Tetracycline staining (? in combination with
restorative techniques) Traumatic pulpal changes White spots Brown spots (not as good response)
CONTRAINDICATIONS
Patients with high/unrealistic expectations
Decay and active peri-apical pathology (must be resolved first)
Pregnancy/Breastfeeding
Sensitivity/cracks/exposed dentine
Existing crowns / large restorations (anteriorly)
Elderly patients with visible recession and yellow roots (roots don’t bleach as readily as crowns)
If patients cannot afford changing existing restorations post-bleaching
Effects on
Soft tissues
Cervical resorption
Pulp
Hardness of teeth
Tooth coloured restorations
Adhesive bond strength
-changes composition of enamel and dentine, therefore defer definitive adhesive restorations until 2 weeks (at least 10 days) after bleaching completed
BLEACHING
Definition “any treatment procedure or method a dental professional might prescribe to whiten the color and brighten your teeth”
10-15% carbamide peroxide used as a oral disinfectant since late 1960s – LONG CLINICAL HISTORY
BLEACHING TECHNIQUES
Vital bleaching : • Home use of 10 % (15%, 20% ALSO)
carbamide peroxide in a dental tray• “In office bleaching” (~30% carbamide
peroxide) carried out in single visit (photo initiation) plus additional home use of carbamide peroxide 10% to “top up”
Non-vital bleaching : • (A.k.a Walking bleaching)• The ‘Inside/Outside’ method using 10 %
carbamide peroxide
MATERIALS
1. Hydrogen peroxide (HP): H2O2
2. Carbamide peroxide: CH6N2O3 much more stable than hydrogen peroxide, hence it’s preferred use
• Urea stabilises and buffers HP – shelf life!
• A 10% Carbamide peroxide solution contains 3% HP, 7% Urea
3. Tetrahydrate sodium perborate: NaBO3 (Borax) mixed with water- decomposes to HP.
MATERIALS
Why 10% CP most widely used?
• 10% is the only bleaching concentration approved by the FDI
• Majority of clinical data on 10%, if a lawsuit ensued – could be criticized for using something less well “tested”
• Higher concentrations= increased sensitivity and harmful effects
MODE OF ACTION
Thought to be due to the ingress of oxidisers and oxygenating molecules through enamel micropores.
Break/cleave pigment bonds and allow molecules to diffuse through the tooth
&/or become smaller and absorb less light and hence appear lighter
MODE OF ACTION 2
When bleach is applied to the tooth it passes from the incisal edge to the apex of the tooth through the enamel, dentin & pulp chamber within 5- 15 minutes.
Hydrogen Peroxide breaks down very rapidly to water, an oxygen ion and oxygen free radicals. The 3 or 4 most active free radical species are OH- 95%, OOH- 2.3% & O- 2.3%.
H2O
OOH-
O-
OH-H2o2
O2
MODE OF ACTION 3
The oxygen molecules then
attach to the double carbon
bonds (colour stain molecules) and break them down into
single carbon bonds, thus disfiguring their internal colors.
The Single carbon bonds reflect light and therefore make teeth appear brighter and whiter. The changed molecules are now translucent.
The molecules may also now diffuse through the pores more readily because of their reduced size
OH-
OOH-
O-
DCB
DCB
SCB SCB
BREAK DOWN THE STAIN MOLECULES
LEGAL SITUATION
The situation at present is that it is illegal in the UK to supply a product for the purpose of tooth whitening, if that product contains or releases more than 0.1% Hydrogen Peroxide.
Companies are able to supply as a “chemical” only i.e. without instructions for use in bleaching
10% CARBAMIDE PEROXIDE RELEASES ~3% HYDROGEN PEROXIDE
SO ESSENTIALLY IT’S ILLEGAL PRACTICE...
LEGAL SITUATION
However
Chief Dental Officer Statement 2000:
“The Department of Health would not
seek to interfere with a dentist’s
therapeutic decision to utilize a
bleaching technique where a dentist
considers this to be in the best interests
of the patient’s overall oral health care”
LEGAL SITUATION
Tooth whitening update (September 2011)- Dental Protection:
• New European Directive allowing dentists to legally supply products for tooth whitening, which release or contain up to 6% hydrogen peroxide , provided that the patient has been examined by a dentist and the first treatment has been performed by the dentist or under his or her direct supervision.
• Once in place (due for publication in October 2011), the UK Government is obliged to amend the Regulations to reflect this within 12 months.
• 6% HP limit will allow dentists to use 18% CP
GENERAL DENTAL COUNCIL
GDC The GDC believes that it is illegal for non-dental
professionals to be offering tooth whitening treatment.
We advise any member of the public wanting tooth whitening to speak to their dentist.
In our view tooth whitening amounts to the practice of dentistry. The carrying out of dentistry by non-registrants is a criminal offence. We are committed to protecting the public by investigating and prosecuting people who are not registered with us and who perform, or provide clinical advice about, tooth whitening
BEWARE
http://www.smilestudiowirral.co.uk/procedure.html
http://www.circlesmk.co.uk/pages/teeth.html
ETHICAL CONSIDERATIONS
The end point is fixed for all teeth and this must be explained fully to the patient.
The Professional should explain the various treatment options, incuding bleaching alternatives such as toothpastes, OTC, at home tray and in-office so that an informed decision can be made.
You must not lead a patient to believe that in-office bleaching will yield better results than home bleaching.
LIVERPOOL UNIVERSITY DENTAL HOSPITAL
At the LUDH, our bleaching protocol states:
“tooth bleaching should only be done if there is a real, clearly-defined clinical need to provide this form of treatment and not merely for the cosmetic aspirations of a patient”.
NON-VITAL BLEACHING
Spasser (1961) - sodium perborate sealed within canal (walking bleach)
Nutting and Poe (1963, 1967) – combination walking bleach (perborate and HP)
Now carbamide peroxide 10% used widely Known as walking bleaching
Indications:
To whiten endodontically treated, discolored teeth.
NON-VITAL BLEACHING- RISK:
• External (cervical) resorption, especially when used with thermocatalytic activation (heated instrument within pulp chamber)
• Heithersay found incidence increased when associated with trauma (3.9-9.7%) and orthodontic treatment (24%)
CLINICAL RELEVANCE:
Pre-operative radiograph• ensure no pathology (external resorption)
prior to commencing procedure• medico-legal
Warn patient if previous orthodontic treatment or trauma- higher risk
Sealing GP with a 2mm RMGIC (minimum 2mm to prevent ingress of bleach into pulp chamber
WARNINGS
Warn patient:• May not improve shade• May reverse, and patient may need to repeat
procedure in future at own cost• May require other treatment: veneer/crown• Tooth is hollow whilst carrying out bleaching and
patient must be careful, do not bit into hard foods, tooth may fracture!
• Cervical resorption? Previous trauma/ortho• If temp filling lost must see dentist urgently
(walking bleach)
NON-VITAL BLEACHING
1. History taking & examination
2. Examine the radiograph to establish adequate RCF
3. Take shade and photograph
4. Rubber dam isolation- single tooth
5. Remove all filling material and gutta percha 2-3mm apical to CEJ (Williams/PCP 2 probe used).
6. All restorative material must be removed to allow bleaching agent to contact the internal tooth structure.
7. Mix RMGIC and place 2mm thickness to assure a seal. Light cure for 20s.
8. Express Carbamide Peroxide into the cavity (use a small tip, e.g. the tips used for acid etch).
NON-VITAL BLEACHING
9. Place tiny cotton pellet into gel. Leave 1.0 to 1.5mm of space to accommodate the provisional restoration.
10.Place a GIC provisional restorative material to seal the access opening, check occlusion.
11.Repeat the procedure every 3 to 7 days until the desired color change is achieved.
12.Remove provisional restorative material and bleaching material to level of GI sealing material. Rinse and clean access opening. Place a temp restoration.
13.A definitive resin composite restoration of a light colour should not be placed before 14 days after the bleaching process.
“INSIDE-OUTSIDE” BLEACHING
Essentially same technique as Non vital bleaching
1. Pre-op radiograph (assess endo)
2. Re-open access cavity
3. Ensure chamber free of GP
4. Seal off the root filling with resin-modified GIC
5. Place the 10% gel (may be higher) into a single tooth tray with labial and lingual reservoirs.
6. Insert tray into the mouth. Remove excess as necessary. This should be kept in position for at least 2 to 3 hours and preferably overnight.
7. Clean the access cavities out with a toothbrush or interproximal brush.
“INSIDE-OUTSIDE” BLEACHING
8. No limit to how many times the material can be changed and changing the material every 2 to 3 hours will probably speed up the process.
9. The access cavity should ideally left open for no longer than necessary (suggested 3 days?)
10. The chamber should be cleaned out thoroughly and temporised.
11. A definitive resin composite restoration of a light colour should not be placed until 14 days after the bleaching process.
LUDH- PROTOCOL 1- Home Bleaching (aka Night Guard Vital Bleaching)
Make a diagnosis of the cause(s) of discolouration and record this in the notes.
Treatment plan: Discuss the various alternative treatment options to bleaching teeth, e.g. no treatment, veneers, crowns.
Check that the patient is not allergic to peroxide or plastic.
Identify the teeth for bleaching **check their periapical status on radiograph.
PROTOCOL 2
• Record the shade of the discoloured teeth and write that in the notes.
• Photograph if possible (with shade tab)
• Obtain patient consent• Warn restorations will not
change colour*• Take alginate impressions for
tray- lab prescription*• Fit bleaching trays, ensure
good fit and comfortable• Advise patient on procedure-
demo use, give leaflets
PATIENT INFORMATION
Using the 10% CP
(Home Bleaching )
1. Brush teeth and floss as normal before each use.
2. Advise the patient to remove the tip from the syringe containing the 10% carbamide gel and to extrude a little (~1mm) of the gel into the deeper and front parts of the tray. (No more than ½ a syringe). Place gel in the tray on the cheek and the tongue side of the back teeth.
3. Seat the tray over the teeth and press down firmly.
4. A finger, a tissue, or a soft toothbrush should be used to remove excess gel that will flow beyond the edge of the tray.
PATIENT INFORMATION
5. Rinse gently and do not swallow. The tray is usually worn whilst sleeping or a minimum of 2 hours.
6. In the morning, remove the tray and brush the residual gel from the teeth. Rinse out the tray and brush it. Store it in a safe container.
The patient should not eat, drink or smoke while bleaching trays in mouth.
10% CP should not be exposed to heat (decomposes), sunlight or extreme cold. Store in a fridge and keep away from reach of children.
PATIENT INFO 2
• Advise the patient that it will probably take about 2-6 weeks to achieve satisfactory result• Nicotine stain 1-3 months
• Tetracycline stain 2-6 months, sometimes 12
• Further restorations
may be required
POST WHITENING INSTRUCTIONS
The Next 24 – 48 hours are important in enhancing & maximizing whitening results.
Avoid substances which may stain teeth Such as: Red wine, coca cola, coffee, tea
Sensitivity: Teeth can be sensitive for 24-48 hours (esp after in office bleaching). It can range from a dull ache in the teeth to sharp pains various teeth. Take Panadol or Nurofen as required.
SENSITIVITY
55% to 75% of patients experience sensitivity
Cause: •Passage of hydrogen peroxide through enamel and dentine to the pulp•Manipulation of teeth
SENSITIVITY
At risk patients:
Large pulp chambers Exposed root surfaces Abfraction, attrition,
erosion, abrasion lesions Over wearing of trays Improper fit of trays High concentrations of
bleaching agent No long-term effects in
the literature
•Decrease wearing time/concentration
•Desensitizing toothpaste–Potassium nitrate
• works on the nerve of the tooth•10 - 30 mins in a tray
–Neutral Sodium Fluoride •occludes the dentinal tubules ( 4-6 weeks)
•Relief gel, Tooth mousse–Amorphous Calcium Phosphate
TREATMENT OF SENSITIVITY
MAKING THE TRAY
• Take alginate impressions of arch(es) to be bleached
• Technician to cast up and block-out the labial aspects of the teeth to be bleached if using reservoirs- recommended (lab technicians add flowable composite onto labial aspects of teeth)
• Make a thin vacuum-formed soft tray from a thermoplastic material
• Check this carefully on the model to ensure there are no sharp areas of the tray that might irritate the gingival margins.
LABORATORY PRESCRIPTION:
Please:
1. Pour study models in dental stone
2. Place composite resin on labial surfaces on e.g. UR5-UL5, LR5-LL5 (+/- palatal surfaces), kept short of gingival margins
3. Make upper and lower full arch, 1mm thickness, soft pull down bleaching trays which are well adapted and trim to the level of the gingival margins
REFERENCES
DENTAL PROTECTION POSITION STATEMENT ON WHITENING
Dr Van Haywood and Dr Harald Heymann published the original technique, called Nightguard Vital Bleaching, in an article in 1989
http://www.dentalprotection.org/United_Kingdom/News_And_Information/Position_Statements/20061014_ps_whitening.aspx
School of Dental Sciences - Liverpool University Dental Hospital
Protocols for Tooth Bleaching/Whitening (AJP)
Suliman 2004 - Dental Update papers (links on vital)
FURTHER READING
1. Greenwall, Linda. Bleaching techniques in restorative dentistry : an illustrated guide
2. Haywood, Van B. TitleTooth whitening : indications and outcomes of nightguard vital bleaching / Van B. Haywood; Quintessence Publishing, 2007.
3. Van Haywood’s article: Frequently Asked Questions About Bleaching; Compendium / April 2003
4. GOLDSTEIN, Ronald E Complete dental bleaching; 1995; Quintessence
5. Sulieman M. An Overview of Bleaching Techniques: 1. History, Chemsitry, Safety and Legal Aspects. Dent Update 2004; 31:608-616
6. Sulieman M. An Overview of Bleaching Techniques: 2. Night Guard Vital Bleaching and Non-Vital Bleaching. Dent Update 2005; 32: 39-46
LUDH- PROTOCOL 1
Make a diagnosis of the cause(s) of discolouration and record this in the notes.
Discuss the various alternative options to bleaching teeth, for instance, veneers, crowns and post crowns.
Check that the patient is not allergic to peroxide or plastic.
Identify the teeth for bleaching **check their periapical status on radiograph.
PROTOCOL 2
• Record the shade of the discoloured teeth and write that in the notes.
• Photograph if possible (with shade tab)
• Record that in the notes and obtain patient consent• Warn restorations will not
change colour*• Take alginate impressions for
tray- lab prescription*• Fit bleaching trays, ensure
good fit and comfortable• Advise patient on procedure-
give leaflets
PROTOCOL 3
• Check for the presence of composites, veneers, crowns at adjacent and opposite teeth and warn patients that these will not change colour with bleaching and may need to be redone if bleaching is undertaken as the colour mismatch may become much more apparent following bleaching.
• If possible draw a diagram to remind the patient of the presence of such restorations and keep a copy in the notes.
• The teeth will change colour with bleaching but the existing composites, veneers, or bridges will not change colour.
• If it is subsequently necessary to make these the same colour as the bleached teeth, significant numbers of restorations may need to be redone.
• White spots will become whiter in initial stages, but almost always revert.
• Record in the notes that this has been discussed
PROTOCOL 4
Advise the patient that the necks of the teeth may take longer to lighten.
If there is a lot of recession – must inform pt root surfaces may not bleach
Temporise carious teeth and leaking restorations. Very old amalgam fillings may leave a dark purple colour on the bleaching tray. It is prudent to polish these restorations with conventional multibladed tungsten carbide burs before commencing.
Bleaching should not be undertaken whilst patients are known to be pregnant or breast-feeding.
HISTORY (adapted from data in Haywood)
Year Authors Innovation1799 Macintosh Chloride of lime is invented - Called bleaching powder1884 Harlan 1st Hydrogen peroxide use
1958 PearsonUsed 35% HP inside tooth and suggested 25%HP with heated lamp
1961 Spasser Perborate sealed within tooth - "walking bleach"
1965 StewartThermocatalytic Technique - pellet saturated with suoperoxyl and heated with an instrument inside pulp chamber.
1987 FeinmannIn office bleaching using 30% H2O2 and heat from bleaching light
1989 Croll Microabrasion technique1989 Haywood and Heyman 10% CP used in trays overnight "Nightguard Vital Bleaching"1990 Bleaching products available OTC - contraversial !
1991 Bleaching materials were investigated and the FDA called for safety studies. Ban was lifted after 6months
1991 Numerous authors Power bleaching using 30% HP and light activiation1996 Rayto Laser tooth whitening1997 Settembrini et al Inside-Outside bleaching technique1998 Carrilo et al Open pulp chamber with CP inside
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