tx of intrinsic discolouration in permanent incisors

Question 1

tx options for discoloration

5

Answer 1

enamel microabrasion
bleaching
resin infiltration (ICON)
localised composite Rxs
veneers - composite

Question 2

pre-op records for all discoloured teeth

Answer 2

• standardisation
• clinical photos
• shade
• sensibility testing, check for sensitivity
• diagram of defect
• radiographs if clinically indicated
• pt assessment e.g. VAS - Visual Analogue Scale - see how pt feels before and after tx

Question 3

indications for HCl-pumice microabrasion

Answer 3

trauma to primary incisors
fluorosis
decalcification after fixed ortho
MIH

Question 4

pre-tx preparation for HCl-pumice microabrasion

Answer 4

PPE - pt must be wearing glasses and bib
clean teeth with pumice and H2O
petroleum jelly to gingivae &lips

MUST place dam and wedges IP between every tooth

• dry dam - has earloops
• caulking agent (oraseal)

Sodium bicarbonate guard (behind teeth)

• and have more available

Question 5

HCl-pumice microabrasion method

Answer 5

• 18% HCl acid pumice slurry in slowly rotating rubber cup for 5secs press hard on labial surfaces
• wash direct into aspirator after every 5secs application
• remove dam
• FV
  Profluorid etc not Duraphat
• polish with finest sandpaper disc
  final polish with toothpaste

Question 6

HCl-pumice microabrasion conc

Answer 6

18% HCl pumice slurry

Question 7

max HCl-pumice microabrasion application

Answer 7

10 x 5secs

Question 8

why shouldn’t you use Duraphat after HCl-pumice microabrasion?

Answer 8

colophony is yellow - teeth are more porous so may take up stain

Question 9

HCl-pumice microabrasion - why sandpaper discs polsih at the end ?

Answer 9

SEM (systematic evidence map) evidence shows a compacted, relatively prismless layer of surface Enamel
this changes the optical properties of Enamel so areas of intrinsic discolouration become less perceptible

Question 10

dental txs and enamel loss - prophy with toothpaste

Answer 10

5-10um

Question 11

dental txs and enamel loss - prophy with pumice

Answer 11

5-50um

Question 12

dental txs and enamel loss - ortho bracket bonding/debonding

Answer 12

5-50um

Question 13

dental txs and enamel loss - acid etch

Answer 13

10um

Question 14

dental txs and enamel loss - 10 x 5secs HCl pumice microabrasion

Answer 14

100um

Question 15

Example of proprietary kit for microabrasion

Answer 15

Opalustre (ultradent)

• 6.6% HCl

Prema kit

• 10% HCl

Question 16

advantages of HCl-pumice microabrasion

Answer 16

easy
conservative
cheap
minimal maintenance
fast-acting
effective
permanent results
can use before/after bleaching
removes yellow-brown, white and multicoloured stains
 - best on brown stains

Question 17

HCl-pumice microabrasion disadvantages

Answer 17

• removes E -sensitivity
• HCl compounds caustic
• requires PPE for pt, dentist and nurse
• prediction of tx outcome is difficult
• must be done in surgery
• cannot be delegated

Question 18

post op instruction for microabrasion

Answer 18

• teeth dehydrated after procedure
• porous
• warn pt to avoid highly coloured food and drinks for at least 24hrs
• will take up stains easily - avoid anything that will stain a white t shirt - tomato based, curry, cola

Question 19

reviewing HCl-pumice microabrasion

Answer 19

• review in 4-6wks and take post-op photos
  (when fully rehydrated)

Question 20

bleaching regulations

Answer 20

• EU directive 2012
  can whiten >18yo with up to 6% H2O2
• GDC 2014
  “products containing/releasing 0.1-6% H2O2 cannot be used on U18yo except where such use is intended wholly for the purpose of txing/preventing disease” -
  ( incs discolouration due to hypomineralisation, fluorosis, trauma etc)

Question 21

options for bleaching

Answer 21

external vital bleaching

• chair side ‘power’ bleaching
• at home nightguard

internal non-vital bleaching

• inside outside
• walking bleach

Question 22

what to warn pt about future when doing bleaching?

Answer 22

effects of bleaching aren’t permanent

as get older may have to pay in future

Question 23

vital chair side bleaching conc

Answer 23

unstable, rapidly reacting H2O2 usually 15-38%
(= 75% carbamide peroxide)
increased risk to STs and eyes

Question 24

nightguard vital bleaching gel and tray design

Answer 24

10% carbamide peroxide gel

cut windows in customised tray over any teeth you don’t want to bleach

Question 25

nightguard vital bleaching pt instructions

Answer 25

``` brush teeth thoroughly apply a little gel to tray set over teeth and press down remove excess rinse gently, don't swallow wear overnight (or for at least 2hrs) remove, brush tray and rinse cold water ```

Question 26

timescale of vital nightguard bleaching

Answer 26

about **3-6 weeks** keep going until acceptable colour (as long as not too many side effects) can be used as an **adjunct to microabrasion**

Question 27

what does 10% carbamide peroxide gel break down into?

Answer 27

- **3% H2O2 and 7% urea** then catalases and peroxidases - water, ammonia, CO2

Question 28

advantages of non-vital bleaching

Answer 28

simple tooth conserving original tooth morphology **gingival tissues** not irritated by Rx adolescent gingival level not a Rx consideration **no lab** assistance for 'walking bleach'

Question 29

non-vital bleaching tooth selection

Answer 29

- adequate root filling no clinical/radiological disease - anterior teeth without large Rxs may need to replace composites after bleaching e.g. trauma - not amalgam intrinsic discolouration - not fluorosis or tetracycline discolouration (vital cases)

Question 30

2 method of non-vital bleaching

Answer 30

- walking bleach - inside-out method

Question 31

walking bleach

Answer 31

oxidising process allowed to proceed over days. seal inside tooth remove root filling to below gingival margin - adult bur - miniature head - clean with ultrasonic tip bleaching agent on cotton wool cover with dry cotton wool seal **GIC/IRM** renew bleach - ideally **no more than 2 weeks** between its appts as oxidation process will have finished if no change after 3-4 renewals stop **6-10 changes** total

Question 32

walking bleach regression

Answer 32

50% 2-6yrs

Question 33

combination inside out bleaching in office aspect

Answer 33

**10% Carbamide peroxide gel** * 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)

Question 34

combination inside out bleaching home aspect

Answer 34

* pt applies bleaching agent to back of tooth and tray * pt keeps access cavity clean - replacing gel removes food debris etc * wear all the time except eating and cleaning * gel changed about every 2 hours except overnight

Question 35

non-vital bleaching restoration of pulp chamber

Answer 35

nsCaOH paste for 2wks, seal in with GIC then: 1 - white GP and composite resin - facility to rebleach OR 2 - incrementally cured composite - no internal rebleaching but stronger tooth - veneer or crown prep if regression

Question 36

potential complications of non-vital bleaching

Answer 36

**ECR** - rare, more likely if prev trauma spillage of bleaching agents failure to bleach over bleach **brittleness** of tooth crown

Question 37

preventing ECR

Answer 37

- layer of cement over GP - nsCaOH in tooth for 2 weeks before final restoration

Question 38

preventing ECR - layer of cement over GP

Answer 38

* prevents bleaching agent from getting to external surface of root (not for inside-out technique) * can prevent adequate bleaching of cervical area

Question 39

preventing ECR - nsCaOH in tooth for 2 weeks before final restoration

Answer 39

**reverses any acidity** in PDL that might have occurred if had got to external surface of root

Question 40

bleaching - effects on ST

Answer 40

concern? short-term exposure - minor ulceration/irritation - plaque reduction - aids wound healing long-term exposure (theoretical)? - delayed wound healing - PD harm - mutagenic potential

Question 41

Tooth mousse - main ingredient and function?

Answer 41

- **Recaldent CPP-ACP** (casein phosphopeptide-amorphous Ca phosphate) - milk derived protein - Promote remineralisation - Adjunct to microabrasion and bleaching (evidence not great)

Question 42

suggested use of tooth mousse from manufacturer as an adjunct to bleaching and microabrasion

Answer 42

- after bleaching : 2wks home application - poorly demarcated hypo mineralised lesions, mild/mod fluorosis : after microabrasion and for 4wks home application (pea sized at night before bed)

Question 43

what is resin infiltration?

Answer 43

- infiltration of E lesions with **low viscosity** light-curing resins - surface layer is **eroded**, lesions **desiccated** (dried with **ethanol**), and apply resin infiltrant - resin penetrates lesion driven by **capillary forces** - infiltrated lesions lose their discoloured appearance and look similar to sound E

Question 44

brand for resin infiltration

Answer 44

ICON

Question 45

resin infiltration method

Answer 45

clean teeth and rinse apply and rub in etch gel (Icon Etch). 2mins working time rinse and apply Icon Dry. 30s visual inspection - insufficient result/lesion not accessible repeat until good masking of white spots, lesion accessible apply separation sheets Icon Infiltrant. 3mins remove excess - blow light cure 40s 2nd infiltration to compensate for polymerisation shrinkage polish

Question 46

to reduce/not to reduce enamel for veneers?

Answer 46

``` aesthetics relative tooth position e.g. instanding incisor would be good to build it out a bit masking dark stain age (v young teeth large pulp) psyche plaque removal ```

Question 47

insufficient enamel reduction consequence

Answer 47

- over contouring - increases plaque retention and - stagnation (salivary flow) at the gingival margin, esp in those with poor OH

Question 48

bond strength of comp in enamel reduction

Answer 48

Significantly increased after partial removal of buccal E

Question 49

composite veneers

Answer 49

direct - freehand/putty guide indirect e.g. BellGlass - often for amelogenesis imperfecta