Treatment of discoloration

Question 1

What Tx options are there for discoloration

Answer 1

Enamel microabrasion

Bleaching, vital & non-vital

Resin infiltration technique

localised composite restoration

Veneers

Question 2

What pre-op records are required for discolored teeth

Answer 2

Standardisation of recording of aesthetic procedures

Clinical photos

Shade

Sensibility testing, check for sensitivity

Diagram of defect

Radiographs if clinically indicated

Patient assessment

Question 3

What is required for the HCL pumice technique

Answer 3

PPE

Patient Must be wearing glasses and bib

Clean teeth with pumice and water

Petroleum jelly to gingivae

Rubber dam

Place sodium bicarbonate guard

Have more sodium bicarbonate available

Question 4

What is the technique for HCL pumice

Answer 4

Once dam is on and teeth are dry place wedjets betweeen teeth

HCL pumice slurry in slowly rotating rubber cup for 5secs

Wash direct into asspirator after 5s application

Fluoride varnish applied, do NOT use duraphat as its coloured

Polish with finest sandpaper disc

Final polish with toothpaste

Question 5

What the maximum application for the HCL pumice slurry

Answer 5

Maximum 10 x 5 second applications

Question 6

Why is a sandpaper disc used at the end

Answer 6

SEM evidence shows a compacted, relatively prismless layer of surface enamel. This changes the optical properties of the enamel so that areas of intrinsic discolouration become less perceptible

Question 7

What is the enamel loss in prophy with toothpaste

Answer 7

5-10 microns

Question 8

What is the enamel loss in prophy with pumice

Answer 8

5-10 microns

Question 9

What is the enamel loss in ortho bracket bonding/debonding

Answer 9

5-10 microns

Question 10

What is the enamel loss in acid etching

Answer 10

10 microns

Question 11

What is the enamel loss in 10 x 5 secs HCL pumice microabrasion

Answer 11

100 microns

Question 12

What are the Adv of microabrasion

Answer 12

Easily performed

Conservative

Inexpensive

Teeth need minimal subsequent maintainence

Fast acting

Removes yellow-brown, white an multi-coloured stains

Effective

Results are permanent

Can use before or after bleaching

Question 13

What are the DisAdv of microabrasion

Answer 13

Removes enamel

HCl acid compounds are caustic

Requires protective apparatus for patient, dentist and dental nurse

Prediction of treatment outcome is difficult

Must be done in dental surgery

Cannot be delegated

Final result you wont see instantly

Question 14

What would you say to a pt after carrying out microabrasion

Answer 14

Dont eat or drink anything that would stain a white tshirt as it’ll stain your teeth again for at least 24hrs

Question 15

How long till the review period after microabrasion and what must it involve

Answer 15

Review patient 4- 6 weeks after microabrasion and take post op photographs

Question 16

What does the GDC say about bleaching under 18’s teeth

Answer 16

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 treating or preventing disease

Question 17

What options are there rfor tooth bleaching

Answer 17

Vital bleaching (external vital bleaching)
-Chairside- ‘power bleaching’
-Night guard vital bleaching ‘at home’

Non- vital (dead tooth) bleaching (interbal non-vital bleaching)
-‘inside outside’ technique
-‘walking bleach’ technique

Question 18

Are the effects of dental bleaching permanent

Answer 18

No

Question 19

When chairside vital bleaching what is used

Answer 19

unstable, rapidly reacting hydrogen peroxide usually 15-38% (equivalent to 75% carbamide peroxide)

Question 20

When vital bleaching at home (nightguard vital bleaching) what is used

Answer 20

10% carbamide peroxide

Question 21

What instructions are given to the pt for nightguard bleaching

Answer 21

Brush teeth thouroughly

Apply a little gel to tray

Set over teeth and press down

Remove excess

Rinse gently, do not swallow

Wear overnight (or for at least 2 hours)

Remove brush try with brush and rinse with cold water

Question 22

What is the timescale for night guard bleaching

Answer 22

approx 3-6wks, until acceptable colour

Question 23

What is the chemical reaction of carbamide peroxide

Answer 23

10% carbamide peroxide

turns into 3% hydrogen peroxide, 7% urea

Then reacts with catalases and peroxidases

Turns into Water, ammonia and carbon dioxide

Question 24

What are the Adv of non-vital bleaching

Answer 24

Simple

Tooth conserving

Original tooth morphology

Gingival tissues not irritated by restoration

Adolescent gingival level not a restorative consideration

No laboratory assistance for ‘walking bleach’

Question 25

How do you decide a tooth is good for non-vital bleaching

Answer 25

No nerve in tooth

Adequate root filling
-no clinical disease
-no radiological disease

Anterior teeth without large restorations

Not amalgam intrinsic discolouration

Not fluorosis or tetracycline discolouration

Question 26

What are the non-vital bleaching methods

Answer 26

Walking bleach (bleach in tooth and sealed up)
-oxidising process allowed to proceed gradually over days

‘Inside-out’ method
-10% carbamide peroxide gel, can seal in if co-op an issue

Question 27

How much root filling do you want removed in non-vital bleaching

Answer 27

Removed below the gingival margin

Question 28

What is the technique for walking bleaching

Answer 28

Access created

Root filling removed below gingival margin

Bleaching agent on cotton wool placed in

Cover with dry cotton wool

Seal with CIC/IRM

Question 29

For walking bleach what is the frequency of placing in bleach

Answer 29

Renew bleach – ideally no more than 2 weeks between appointments

If no change after 3-4 renewals stop

6-10 changes total

Question 30

When do the results of walking bleach start to regress

Answer 30

Regression 50% at 2-6 years

Question 31

What is the technique for Combination –’inside out’ bleaching

Answer 31

Access cavity of tooth open

Do not necessarily need GI lining

Custom made mouthguard (cut windows in guard of the teeth you don’t want to bleach!)

Patient applied bleaching agent to back of tooth and tray

Patient keeps access cavity clean, replacing gel removes food debris etc
10% Carbamide peroxide is bleaching agent of choice

Worn all the time except eating and cleaning

Gel changed every 2 hours or so except during the night

Question 32

After bleaching how do you restore the pulp chamber

Answer 32

Non setting calcium hydroxide paste for 2 weeks, seal in with GIC.

Then Either:

-White GP and composite resin, facility to re-bleach

-Incrementally cured composite, no re-bleaching but stronger tooth

Veneer or crown prep if regression

Question 33

What are the potentional complications involved with non-vital bleaching

Answer 33

External cervical resorption (more common in trauama cases)

Spillage of bleaching agents

Failure to bleach

Over bleach

Brittleness of tooth crown

Question 34

How would you prevent external cervical resorption

Answer 34

Layer of cement over GP
-Prevents bleaching agent from getting to external surface of root (not for inside-out technique)
-Can prevent adequate bleaching of cervical area

Non setting calcium hydroxide in tooth for 2 weeks before final restoration
-Reverses any acidity in PL that might have
occurred

Question 35

What are effect of bleaching agents on soft tissues

Answer 35

Short term exposure
-Minor ulceration/irritation
-Plaque reduction
-Aids wound healing

Long term exposure
-delayed wound healing
-periodontal harm
-Mutagenic potential

Question 36

What is the technique of resin infiltration

Answer 36

infiltration of enamel lesions with low-viscosity light-curing resins

surface layer is eroded, lesions desiccated and a resin infiltrant is applied.

Resin penetrates lesion driven by capillary forces

Infiltrated lesions lose their discoloured appearance and look similar to sound enamel