Discolouration of teeth

Question 1

Aetiology of discolouration

Answer 1

Extrinsic/intrinsic
System/local
Enamel/dentine
Congenital/acquired

Question 2

Extrinsic factors causing tooth discolouration

Answer 2

Food/drink
Smoking
Poor OH
Drugs

Question 3

Intrinsic factors causing discolouration of enamel

a) local
b) systemic

Answer 3

a) trauma, idopathic, caries

b) amelogenesis inperfecta, flourosis, systemic illness, idiopathic

Question 4

Intrinsic factors causing discolouration of dentine

a) local
b) systemic

Answer 4

a) necrotic pulp, metal ions, root canal filling materials, caries,
b) dentinogesis imperfecta, tetracycline, bilirubin

Question 5

Amelogenesis imperfecta manifestations?

Answer 5

Normal shape
Brown markings
Opaque

Question 6

Treatment of discoloured anterior teeth

Answer 6

Enamel micro abrasion
Tooth whitening
Veneers (composite/porcelain)
Crowns

Question 7

Indications for micorabrasion?

Answer 7

White/brown intrinsic blemishes in outer layer of enamel
Turner teeth (hypoplasia)
Flurosis
Idiopathic speckling
Post-ortho demin 
Prior to veneers

Question 8

Microabrasion contraindications

Answer 8

Non-vital teeth or tetracycline staining (within the dentine)

Question 9

Microabrasion technique

Answer 9

Clean teeth
Rubber dam
Seal dam
Sodium bicarbonate and water paste on rubber dam around teeth

Etchant for 15 secs and wash off
Repeat up to 10x
Fluoride gel on teeth to mineralise
Polish with toothpaste

Question 10

HOw can vital tooth whitening be characterised?

Answer 10

Over the counter - toothpaste
In-surgery - heat and light - 15% carbamide peroxide gel
Tray-based - 15% carbamide peroxide gel over night

Question 11

Problems with over the counter teeth whitening?

Answer 11

Self-diagnosis - may be careis

Question 12

Indications of vital whitenign?

Answer 12

Severe extrinsic stain
Age related discolouration
Calcified pulp
Fluorosis
Mild tetracylcine

Question 13

Contraindications for vital whitening?

Answer 13

Large pulp
During ortho
Hypersensitive teeth
Severe enamel loss
Extensive restoration
Pregnancy/breast feeding

Question 14

How does teeth whitening work?

Answer 14

Oxidation

Question 15

Consequence of whitening?

Answer 15

If you do it too long - enamel breakdown

Question 16

Materials used for in-surgery tooth whitening?

Answer 16

Rubber dam
Phosphoric acid (etch)
Hydrogen peroxide

Question 17

Tray-based whitening materials?

Answer 17

Carbamide peroxide gel 10% = 3% hydrogen peroxide

Question 18

Effects of whitening on teeth?

Answer 18

Mild sensitivity to temperature changes
Cellular pulp changes
Dameg to enamel
PH of solution
Bond strength to composite

Question 19

Saftey concerns of tray whitening?

Answer 19

JE may be permeable to carbamide peroxide - exposure to lots of cells

Question 20

Why should <18 years not use vital whitening?

Answer 20

Larger pulp chambers
Little secondary dentine
Poorer plaque control (?)
Increased potential for pulpal hyperaemia 
Heat should not be used

Question 21

What is the maximum hydrogen peroxide dose prescribed by dentist for whitneing?

Answer 21

<6%

Question 22

Advantages of non-vital tooth whitening

Answer 22

Simple
Tooth conserving
Original morphology
Gingival tissues
Adolescents
No lab assistance

Question 23

Materials/methods of non-vital whitening?

Answer 23

Thermo-catalytic –> heat source, light or probe release oxygen from bleaching agent

Walking bleach –> oxidising process allowed to proceed gradually over days - seal carbamide peroxide gel in for a week repeatedly

Inside/outside bleach –> bleach tray and open access cavity

Question 24

Indications for non-vital whitenign?

Answer 24

Adequate obturation (remove GP to gingival margin)
No radiological disease
No lareg restorations
Not staining caused by restorative materials (amalgam not reversible)
Fluorosis/tetracylines not appropriate

Question 25

Describe walking bleach technique

Answer 25

Access cavity and pulp chamber restorations removed - GP to gingival margin Freshen dentine inside pulp chamber, etch chamber carbamide peroxide gel into cavity, cotton wool placed over Seal with GIC Return in a week

Question 26

Complications of non-vital whitening?

Answer 26

``` External cervical resorption Spillage Failure to whiten Over whitening Brittleness of tooth crown ```

Question 27

Describe inside/outside non-vital whitening technique

Answer 27

Access pulp chamber squirt carbamide peroxide gel inside Place beaching tray on and squirt into bleaching tray (inside and outside the tooth)

Question 28

Indications for inside/outside NV whitenign?

Answer 28

Single root filled tooth No signs of pathology Impressions Adequate OHI and able to clean tray

Question 29

Arguments for enamel reduction in primary teeth for veneer prep?

Answer 29

Decreases likelihood of over contouring | Better bond strength to composite

Question 30

Arguments against enamel reduction in primary teeth for veneer prep?

Answer 30

Young patient have large pulp chambers and unstable soft tissue

Question 31

Indications for composite e | veneers in children

Answer 31

``` Morphology Diastemata Fractures Failed acid pumice Inherited disorder Growing child ```

Question 32

Indications of porcelain veneers

Answer 32

``` Discolouration Enamel defects Diastemata Malpositioned teeth Malocclusion Poor restorations Ageing Wear patterns ```

Question 33

Contraindications of porcelain veneer

Answer 33

Available enamel | Oral habits