Tooth Whitening Flashcards
what are the extrinsic causes of tooth discolouration
smoking
tea
coffee
red wine
chromogenic bacteria
chlorhexidine
iron supplements
what are the intrinsic causes of tooth discolouration
fluorosis
tetracycline
non-vitality
physiological
dental materials
porphyria
cystic fibrosis
sickle cell anaemia
hyperbillirubinaemia
what should the first method of tooth whitening for extrinsic staining be
hygiene phase therapy
what are the 2 types of bleaching
external vital bleaching
internal non-vital bleaching
what does bleaching do to extrinsic compounds adhered to the tooth
oxidises them leading to smaller molecules which are not pigmented
cause ionic exchange in metallic molecules leading to lighter colour
what is the action of hydrogen peroxide
forms an acidic solution in water
breaks down to form water and oxygen
free radical per hydroxyl is formed which is the active oxidising agent
what is carbamide peroxide
active ingredient which breaks down to produce hydrogen peroxide and urea
what is carbopol
thickening agent which slowly releases oxygen and increases viscosity of the gel making it stay where you put it
allows slow diffusion into enamel
what is the action of urea
raising pH
stabilising hydrogen peroxide
what does surfactant do
allow gel to wet the tooth surface
what are potassium nitrate and calcium phosphate
tooth desensitising agents
what does fluoride do
prevent erosion
desensitising
what are the factors affecting bleaching
time
cleanliness of tooth surface
concentration of solution
temperature
what do you do before you start tooth whitening
ensure patient is dentally fit and no leakage around carious cavity margins
take initial shade
what do you need to warn the patient about
sensitivity
relapse
restoration colour
allergy
might not work
compliance with regime
what are the two types of vital external bleaching
chair side
home
what are the advantages of chair side bleaching
controlled by dentist
can use heat/light
quick results for patient
what are the disadvantages of chair side bleaching
time for dentist
uncomfortable
results wear off quicker
expensive
what is the technique for chair side bleaching
thorough cleaning of teeth
rubber dam
gingival mask
bleaching gel applied to tooth
heat/light applied
wash/dry/repeat
takes 30mins to an hour
what is home bleaching
patient gets custom made trays and bleaches slowly over several weeks
when getting soft splints made for at home bleaching what do you need to tell the lab
stop 1mm short of gingival margin
buccal spacer to allow for placement of gel
what is the technique for at home bleaching
full mouth cleaning in surgery
fit trays
instructions for use
brush and floss teeth at home
load tray with 1mm squared buccal on each tooth
fit tray in mouth for 2 hours but preferably overnight
when would you bleach teeth
age related darkening
mild fluorosis
post smoking cessation
tetracyclin staining
what are the problems with bleaching
sensitivity
wears off
cytotoxicity
gingival irritation
tooth damage
damage to restorations
problems with bonding to tooth
what are the predictors of sensitivity
pre-existing
high concentration of bleaching agent
frequency of change
bleaching method
gingival recession
when would sensitivity resolve
2-3 days after bleaching
what does chlorine dioxide do
strips enamel from tooth surface
has pH of 3
what are the indications for internal non-vital bleaching
non-vital tooth
adequate RCT
no apical path
what are the contraindications for internal non-vital bleaching
heavily restored tooth
staining dur to amalgam
what are the advantages of internal non-vital bleaching
easy
conservative
patient satisfaction
what are the risks of internal non-vital bleaching
external cervical resorption
what is the technique for internal bleaching
record shade
prophylaxis
rubber dam
remove filling from access cavity
remove GP from pulp chamber and place RMGIC over GP to seal canal
remove dark dentine
etch internal surface
place 10% carbamide peroxide gel
cotton wool over this
seal with GIC
repeat procedure at weekly intervals
how long does internal bleaching take
3-4 visits
what is combination bleaching
make access cavity and remove GP, make bleaching tray and place bleach in access cavity and tray and keep in the whole time (week)
what does micro abrasion do
remove discolouration limited to outer layers of enamel
what are indicators for microabrasion
fluorosis
demineralisation with staining
post ortho demineralisation
prior to veneering
what is the micro abrasion technique
clean teeth
rubber dam
mix 18% HCl and pumice
apply to teeth
rub with prophy cup
wash
repeat 10x
remove rubber dam
polish teeth with fluoride prophy paste
apply fluoride gel or varnish
what are the advantages to microabrasion
quick
easy
no long term problems
what are the disadvantages to microabrasion
acid
sensitivity
only for superficial staining
works better for brown stains than white marks
what does resin infiltration do
changes the refractive index of the white area and makes it look like surrounding enamel
what regulations are needed to comply with for tooth whitening
cosmetic products regulations 2012
what is the maximum legal amount of hydrogen peroxide allowed in practice
6%
what age must you be to use 0.1% to 6% hydrogen peroxide
18
what percentage of hydrogen peroxide is allowed on the market in toothpastes
0.1%
