Treating Discoloured Permanent Anterior Teeth in Young Pts

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Created by
Eleanor Jubb

Cards (30)

  • Aetiology of discolouration:
    • There are several classifications for discolouration of teeth. Clinical management lends itself to the classification identifying tissue type, because it is the site of the anomaly which dictates the most appropriate treatment method.
    • Therefore the following classification can be used:
    • Extrinsic staining
    • Intrinsic enamel staining (local causes)
    • Intrinsic enamel staining (systemic causes)
    • Intrinsic dentine staining (local causes)
    • Intrinsic dentine staining (systemic causes)
  • Extrinsic staining can be caused by:
    • Food and drink
    • Smoking
    • Chromogenic bacteria
    • Chlorhexidine
    • Drugs (iron supplements, minocycline)
  • Intrinsic enamel staining can be caused by:
    • Local causes
    • Injury/infection of primary predecessor
    • Idiopathic
    • Caries
    • Internal resorption
    • Systemic causes
    • Amelogenesis imperfecta
    • Fluorosis
    • Systemic illness during tooth formation
    • Idiopathic
    • Tetracycline
  • Intrinsic dentine staining can be caused by:
    • Local causes
    • Necrotic pulp tissue
    • Metallic restorations
    • Root canal filling materials
    • Caries
    • Internal resorption
    • Systemic causes
    • Dentinogenesis imperfecta
    • Hereditary opalescent dentine
    • Tetracycline
    • Congenital porphyria
    • Bilirubin (haemolytic disease of newborn)
  • Acid-pumice microabrasion = a controlled method of removing surface enamel to improve discolouration that is limited to the outer layer of enamel. This is NOT a bleaching technique, more an ‘abrosion’. It is not suitable for non-vital teeth or tetracycline stains.
  • Acid-pumice microabrasion indications:
    • White/brown stains in surface enamel
    • Turner teeth
    • Fluorosis
    • Idiopathic speckling
    • Post-orthodontic treatment demineralisation
    • Prior to veneering
  • Acid-pumice microabrasion materials:
    • Rubber dam
    • Copalite varnish or GIC varnish
    • Sodium bicarbonate/water paste
    • Pumice/18%/hydrochloric acid paste
    • Rubber prophylaxis cup
    • Non-acidulated fluoride varnish (pro-fluoride varnish)
    • Soflex discs
    • Fluoridated toothpaste (white)
    • Proprietary kits can be purchased - 'Prema' (Premier Dental Products) - 'Opalustre' (Optident)
  • Acid-pumice microabrasion technique:
    1. Pre-operative vitality tests, radiographs & photos
    2. Clean teeth w/ pumice + water - dry
    3. Isolate teeth w/ rubber dam & paint Copalite varnish at junction of tooth & dam
    4. Place sodium bicarbonate water paste around area to neutralise any acid drips
    5. Mix 18% HCl + pumice & apply to tooth surface on rubber cup - rotating slowly & contacting for 5s
    6. Wash for 5s
    7. Repeat up to max of 10 applications
    8. Apply FV for 3 mins - NOT Duraphat; yellow
    9. Polish w/ finest Soflex discs
    10. Prophylaxis w/ toothpaste
    11. Warn not to eat coloured food for 24 hours
    12. Review in 1 month
  • Only 50-70% of white enamel defects are sufficiently superficial to be removed with acid-pumice microabrasion. May need follow-up localised composite ‘veneers’. When white flecking removed, the residual colour is quite creamy yellow - this may give rise to dissatisfaction.
  • Bleaching can be broadly divided into VITAL and NON-VITAL. There are also subdivisions within these categories:
    • Non-vital
    • In surgery 'powerbleaching' - thermocatalytic
    • Walking bleach
    • Vital
    • Over the counter preparations (eg toothpaste, boil and form kits)
    • In surgery vital bleaching
    • Matrix bleaching (nightguard vital bleaching)
    • How it works:
    • Thought to be an oxidation process, whereby pigmented carbon ring structures are broken down into colourless structures.
  • Non-vital bleaching:
    • Pulpless teeth discolour often as a result of haemolysis of red blood cells. This can occur from trauma or from incomplete extirpation of coronal pulp tissue during root canal treatment.
    • Haemolysis of rbc’s releases haemoglobin which combines with hydrogen sulphide from bacteria, producing iron sulphide.
  • Non-vital bleaching:
    • Indications
    • Discoloured, well root obturated permanent teeth; no pathology seen on radiographs.
    • Contraindications
    • Discolouration due to metal ions
    • Extensive coronal restoration
  • Non-vital bleaching materials:
    • Vaseline
    • Rubber dam
    • Pumice and water
    • Miniature air turbine head and round steel burs - or normal turbine head and goose-necked burs
    • Zinc phosphate cement
    • 37% phosphoric acid
    • Sterile water
    • Sodium perborate granules (Bocasan)
    • Cotton wool
    • GIC
    • Non-setting calcium hydroxide paste
    • White GP
    • Composite resin
  • Walking bleach technique:
    1. Pre-op x-rays = essential to assess root filling & periradicular status
    2. Clean teeth w/ pumice - note discoloured tooth shade & aim shade
    3. Vaseline on gingivae
    4. Isolate tooth
    5. Remove access & pulp chamber restoration
    6. Remove GP to just beyond dento-gingival junction
    7. Put 1mm zinc phosphate over GP
    8. Etch pulp chamber w/ acid (30s). Wash + dry.
    9. Mix perborate + sterile water -THICK paste. Apply to labial aspect of access cavity
    10. Cover w/dry cotton wool
    11. Seal w/GIC
    12. Repeat weekly until overbleached
    13. Non-setting CaOH & seal w/ GIC for 2/52
    14. Restore w/white GP & composite
  • Problems with walking bleach:
    • External cervical resorption (ECR)
    • Linked with
    • Thermocatalytic methods
    • Previously traumatised teeth
    • No lining over GP
    • Hydrogen peroxide stimulating odontoclastic activity
    • Particularly if H2O2 is used it is suggested that at the end of treatment it is sensible to place non-setting calcium hydroxide for 2/52 in an attempt to prevent ECR.
  • Problems with walking bleach:
    • External cervical resorption (ECR)
    • Studies using sodium perborate and water as bleaching agents have shown success, but longer review periods need to be published.
    • Non-vital teeth can also be bleached by soaking cotton wool pledgets in H2O2 and placing them in the pulp chamber (powerbleaching). This is then activated by heat and light for 20-30 minutes. Consider its use with caution because of case reports highlighting ECR.
    • Spillage
    • Failure to bleach
    • Brittleness of tooth crown
  • Indivations for vital bleaching:
    • Severe extrinsic staining
    • Age-related discolouration
    • Calcified pulp
    • Fluorosis, especially brown stain
    • Mild tetracycline stain
  • In-surgery vital bleaching involves the external application of usually a hydrogen peroxide containing product, heat and light to the labial surfaces of the teeth in the dental chair. It can be used to lighten teeth at the darker end of the ‘normal’ spectrum. Commonly
    used in the USA! NO PLACE IN CHILDREN!!!
  • Materials for vital bleaching:
    • Pumice and water
    • Topical anaesthetic gel
    • Orabase or Vaseline
    • Rubber dam, floss, clamps
    • 37% phosphoric acid
    • Gauze strips
    • Heat-light
    • Hydrogen peroxide solution/preparation (legally up to 6% maximum hydrogen peroxide in the UK, in the US higher concentrations are used)
    • Soflex discs (smooth)
  • Technique for vital bleaching (part 1):
    1. Pre-op x-rays & vitality tests. Check for leaking restorations.
    2. Clean teeth with pumice and water to remove extrinsic stain.
    3. Apply topical anaesthetic gel to the gingival margins.
    4. Coat buccal and palatal gingivae with Orabase gel to protect from bleaching solution.
    5. Isolate each tooth to be bleached using floss ligatures, except the end teeth which should be clamped.
    6. Cover the metal clamps with water moistened gauze to prevent overheating under the heat-light source.
  • Technique for vital bleaching (part 2):
    • 7. Etch buccal & 1/3 of palatal surfaces w/ acid for 60s, wash & dry. Soak gauze in whitening agent & cover teeth.
    • 8. Set heat lamp 13-15in from teeth. Set to mid temp range - turn up until pt can just feel warmth & turn down a little.
    • 9. Reapply bleach every 3-5 mins using cotton bud.
    • 10. After 30 mins remove rubber dam & polish teeth. Apply fluoride drops for 2-3 mins.
    • 11. Post-op sensitivity relieved w/ Paracetamol/Tooth Mousse.
    • 12. Assess change - may be necessary to repeat process. Review periodically; may need to be repeated every year.
  • Vital tray-based bleaching evolved from observed tooth lightening when carbamide peroxide was used in a splint after periodontal treatment. The active ingredients of these systems is carbamide peroxide gel. The exact mode of action is unclear, but again thought to be an oxidising process. 10% Carbamide peroxide breaks down into approx 3% H2O2, and urea. These then break down to oxygen, water, ammonia and carbon dioxide. Urea and H2O2 have small molecular weight and can therefore diffuse rapidly through enamel and dentine. This may explain the transient pulpal sensitivity sometimes experienced.
  • Vital tray-based bleaching materials:
    • Upper impression and working model
    • Custom-fabricated bleaching tray, avoiding gingivae
    • Syringes of gel for home application
  • Vital tray-based bleaching technique:
    1. Alginate impression
    2. Pour up stone/plaster working model
    3. Relieve labial surface of model w/ wax spacer (0.5mm)
    4. Produce 2mm thick soft pull-down vacuum formed splint. Carefully trim away from gingival margin; should be no contact w/ gingivae.
    5. Determine initial shade & record. OHI to pt. Instruct pt to apply gel to internal labial aspect of splint, just on teeth to be bleached.
    6. Length of time splint should be worn varies w/ different systems. Low viscosity gels need topping up.
    7. Review pt 2/52 and 6/52. 80% colour change should have occurred by then.
  • Side effects of vital tray-based bleaching:
    • Gingivae
    • Gingivitis
    • Number of micro-organisms
    • Cell necrosis if concentrated directly on tissue
    • Pulp
    • Mild sensitivity to temperature changes - due to small molecular weight
    • Enamel
    • Insignificant change in enamel surface morphology or subsurface enamel hardness after 6 weeks use
    • Concern that lower pH solutions/gels would cause demineralisation
    • There's an initial decrease in bond strength to composite resins placed immediately after bleaching. This is thought to be because of residual O2 on the tooth surface, which inhibits polymerisation
  • Side effects of vital tray-based bleaching:
    • Under proper conditions w/ careful technique & pt management, bleaching may offer an effective alternative to restoring discoloured vital & non-vital teeth to more normal colour. In some cases it replaces more invasive/expensive procedures, like crowns. It can provide initial/supplementary lightening of teeth, increasing efficacy of other treatment, like veneers
    • If the child experiences significant sensitivity consider alternating gel and toothpaste. Mild sensitivity can usually be controlled by the child using a desensitising toothpaste to brush.
  • For non-vital tooth whitening/bleaching of a discoloured root-filled tooth, the prerequisites for treatment are the same as for walking NV bleach and the plaque control must be excellent (remember they have to keep an unrestored access cavity clean during the whole procedure).
  • Non-vital tooth whitening/bleaching of a discoloured root-filled tooth (part 1):
    1. Baseline records as before; usually a single root filled tooth is dark
    2. Alginate impression of arch containing tooth to be bleached
    3. Lab construction of bleaching tray (hard acrylic), cut away the labial surfaces of one tooth either side of tooth to be bleached so seepage doesn't occur. This will prevent adjacent teeth from bleaching. The corresponding labial surface of the tray (related to the dark tooth) should be trimmed to sit just onto the gingivae. The remaining splint can extend further to help retention.
  • Non-vital tooth whitening/bleaching of a discoloured root-filled tooth (part 2):
    • 4. Fit bleaching tray. OHI.
    • 5. Remove access restoration and ensure sufficient GP removed.
    • 6. Seal GP surface with GIC or similar; NB maintain sufficient depth.
    • 7. Some clinicians 'ultrasonicate' (Cavitron or similar) the exposed dentine within the access cavity prior to placing the first bleach.
  • Non-vital tooth whitening/bleaching of a discoloured root-filled tooth (part 3):
    • 8. Instruct patient how to apply 10% CP gel into access cavity using syringe and how to apply the same CP gel onto labial fit surface of the bleach tray.
    • 9. Instruct to wear for 2 hours periods up to twice daily or during the night whilst asleep (gentle approach in children, adults can wear for longer/more often). Review after 2 weeks.
    • 10. Advise pt to stop when reached desired shade or overbleach occurs.
    • 11. Review and restore as previously.