Treatment of Intrinsic Discolouration

Question 1

What are the treatment options are there for anterior discolouration in children?

Answer 1

Enamel micro-abrasions
Bleaching
Resin infiltration
Localised composite restorations
Venners

Question 2

How many microns do you remove when you acid etch?

Answer 2

10 microns

Question 3

What pre-op records should be taken for all discoloured teeth?

Answer 3

Standardised with future records
Clinical photos
Shade
Sensibility testing
Diagram of defect
Radiographs if indicated
Patient assessment

Question 4

Describe the steps taken to protect operator and patient from the HCL in microabrasion,

Answer 4

Full PPE
Patient wearing glass and bibs
Petroleum jelly on gingiva
Rubber dam placed
Sodium bicarbonate resevoir

Question 5

Describe the process of performing microabrasion for enamel discolouration.

Answer 5

Pre-op steps taken
Protective elements in place
Use HCL/pummice
Apply with slowly rotating rubber cup
Maximum 10x5 second applications per tooth
Teeth washed and aspirated after each 5 seconds
Fluoride varnish applied
Polish with finest sandpaper disc
Final polish with toothpaste

Question 6

Why do we use sandpaper discs after completing microabrasion?

Answer 6

SEM shows a compacted aprysmatic surface enamel layer, this changes the optical properties of enamel, so areas of intrinsic discolouration become less perceptible.

Question 7

Identify the discolouration in this dentition. What managment options are there?

Answer 7

Fluorisis

Accept
Microabraision
Internal/external bleaching
Resin infiltration
Composites
Veneers

Question 8

How many microns of enamel do you remove when you apply toothpaste with a rubber cup?

Answer 8

10 Microns

Question 9

How many microns of enamel do you remove when you apply pummice with a rubber cup?

Answer 9

5-50 microns

Question 10

How many microns of enamel is removed from ortho bracket bonding/debonding?

Answer 10

5-50 microns

Question 11

What are the advantages of microabrasion to remove staining?

Answer 11

Easily performed
Conservative
Inexpensive
Teeth need minimal subsequent maintenance
Fast acting
Removes yellow/brown, white, and multi-colored stains
Results are permanent
Can be used before or after bleaching
Results are permanent

Question 12

What are the disadvantages of microabrasion?

Answer 12

Removes enamel
HCL acid compounds are caustic
Requires protective apparatus for operators and patient
Prediction of treatment outcome is difficult
Must be done in dental surgery
Cannot be delegated

Question 13

What is the review time and key post-op instruction following micro-abrasion?

Answer 13

Review 4-6 weeks after treatment and take post op pictures.

Teeth are dehydrated after procedure, avoid highly coloured food/drink for at least 24 hours.

Question 14

What is the GDC guidance on bleaching for those aged under 18?

Answer 14

Products releasing 0.1-6.0% hydrogen peroxide cannot be used on any person under 18, except where such use is intended wholly for the purpose of treating disease.

This exception includes discolouration due to hypomineralisation, trauma, fluorosis etc.

Question 15

What are the treatment options for bleaching in under 18s?

Answer 15

External vital bleaching
- Chairside
- At home

Non-vital bleaching
- Inside outside technique
- Walking bleach technique

Question 16

What are the instructions to patients regarding nightguard vital bleaching?

Answer 16

Brush teeth thoroughly
Apply a little to each tooth of the tray
Set over teeth and press down
Remove excess
Rinse gently, do not swallow
Wear overnight
Remove and brush tray, rinse with cold water

Question 17

What are the advantages of non-vital bleaching?

Answer 17

Simple
Tooth conserving
Original tooth morphology
Gingival tissue not irritated by restoration
Adolescent gingival level not impacted
No lab assistance for ‘walking bleach’

Question 18

What teeth should be selected for non-vital bleaching?

Answer 18

Adequate root filling
No clinical disease
No radiological disease
Anterior teeth without large restorations or amalgam
Staining not from fluorosis or tetracycline

Question 19

Describe the method for the ‘walking bleach’ technique.

Answer 19

Access cavity opened and filling removed down to gingival margin.

Carbamide soaked cotton wool placed into cavity.

Dry cotton wool over the top.

Cavity sealed with GI or equivalent.

Renew bleach ideally no more than two weeks between appointments. If after 3-4 renewals no change is noted it probably won’t work.

Question 20

Outline the method for ‘inside out’ bleaching.

Answer 20

Patient has an open access cavity. Does not necessarily need lining.

Custom made mouthguard, with windows cut in teeth you don’t want whitened.

Patient applies bleach to back of tray, and wears 24/7 except eating.

Gel reapplied every two hours.

Patient instructed on how to keep cavity clean.

Question 21

What are the potential complications of non-vial bleaching?

Answer 21

External cervical resorption

Spillage of bleaching agents

Overbleach the tooth

Brittleness of crown

Question 22

What step can you take to prevent external cervical resorption when bleaching?

Answer 22

Layer of cement over the GP, to prevent the bleach from leaking into the cervical dentine.

OR

Non-setting calcium hydroxide in the tooth 2 weeks before the final restoration (this reduces acidity in the PDL)

Question 23

Describe the short and long term risks of carbamide gel if it spills onto the soft tissue?

Answer 23

Short term:
- Minor Ulceration/irritation
- Plaque reduction
- Aids wound healing

Long term exposure:
- Delayed wound healing
- Periodontal harm
- Mutagenic potential

Question 24

What is tooth mousse?

Answer 24

CCP-ACP

Caesin phosphopeptide - amorphous calcium

Question 25

What step can be taken to help with sensitivity post micro-abrasion?

Answer 25

Tooth Mousse

Question 26

What is resin infiltration?

Answer 26

Infiltration of enamel lesions with low viscosity light curing resins.

Surface layer is eroded, lesions desiccated and resin infiltrate is applied.

Resin penetrates lesion driven by capillary forces, infiltrated lesions lose their discoloured appearance and look similar to sound enamel.

Question 27

What is a potential drawbacks from enamel reduction for veneer placement?

Answer 27

Overcountouring, which could lead to more plaque retention and stagnation at the gingival margin