AQ

Chapter 43 - Tooth Bleaching (Clinical Practice of the Dental Hygienist, 14th Edition)

Chapter 43: Tooth Bleaching – Study Notes

  • Bleaching vs Whitening

    • Bleaching: involves free radicals and the breakdown of chromogens to lighten tooth color.
    • Whitening: general term for processes that lighten tooth color; can include non-oxidative methods.
    • Color change can extend into the dentin to produce a whitened tooth.

  • Chromogens and Staining

    • Definition: Chromogens are molecules in foods/drinks that alter reflected light, making them appear colored.
    • Staining mechanism: chromogens bind to the enamel surface or salivary pellicle, changing tooth color.
    • Common staining examples: red wine, blueberries, cherries (contain tannins and other chromogenic compounds).
    • Other contributing factors: tannins and acids can enhance discoloration.
    • Types of staining:
    • Extrinsic: on the enamel surface
    • Intrinsic: within the tooth structure
    • Bacterial involvement: some bacteria can produce chromogens, leading to dark staining (e.g., black staining).

  • Tooth Color Changes

    • Determinants: enamel thickness and dentin color influence overall tooth color.
    • Primary driver: dentin color changes more than enamel color; dentin color is typically yellow or gray and can show through due to translucency.
    • Darker teeth take longer to lighten.
    • Each tooth has a maximum color change; additional product or longer contact time may not yield further lightening.
    • Bleaching can cause temporary dehydration, making teeth appear lighter briefly.
    • Color stabilization: typically occurs about ~2 weeks after bleaching.

  • Materials Used For Bleaching

    • Agents: Hydrogen peroxide (HP) and carbamide peroxide (CP) are used to lighten vital teeth.
    • Hydrogen peroxide:
    • Shorter working time because it begins to break down in ~30{-}60\;\text{minutes} per application.
    • Lower pH than CP, potentially increasing risk of demineralization/erosion if used for longer treatment times than recommended.
    • Practical implication: less time per day but more days to achieve color change.
    • Carbamide peroxide:
    • Longer working time due to slower release; can be safely used at home.
    • Higher pH, which facilitates bleaching and can result in less sensitivity.
    • Summary: HP is faster but potentially more irritating; CP is gentler and suitable for home use.

  • Medications Associated with Photosensitivity (Box/Figure reference)

    • Some medications can cause photosensitivity or hyperpigmentation when exposed to light.
    • Be aware of patient history that may increase risk during light-activated bleaching.

  • Decision Making for Tooth Bleaching (Table 43-1)

    • Tooth conditions and typical responses:
    • Yellow color
      • Response: normally excellent.
      • Special considerations: generally straightforward lightening.
    • Enamel white spots
      • Response: variable; may be resistant to bleaching.
      • Special considerations: microabrasion can lessen white spots if lesions are under one-third through enamel; microabrasion after bleaching and color stabilization may improve final result.
    • Brown fluorosis stains
      • Response: may bleach but effectiveness varies; some residual staining may remain.
      • Special considerations: monitor whitening progress; may require adjunctive treatments.
    • Nicotine stains
      • Response: about 80% of cases respond.
      • Special considerations: multicolored bands may not respond well.
    • Tetracycline stains
      • Response: gray stains are the most difficult to lighten; dark grays lighten only slowly.
      • Special considerations: dark cervical third has the poorest prognosis; may go through a splotchy stage before background color lightens.
      • Additional notes: some lines indicate microabrasion may help white spots when enamel is sufficiently intact; longer treatment times are common (see below).
    • General timing cues:
      • Some cases may take 2–3 months of nightly application.
      • Others may require 3–6 months of daily bleaching.
    • Additional notes drawn from the table:
    • Gray stain types (e.g., tetracycline) require particular attention due to prognosis.
    • Background color changes may occur more slowly for certain stains, affecting planning and expectations.

  • Additional Decision Making for Tooth Bleaching (Page 8 content)

    • Minocycline stains: Will respond to bleaching but will take longer than yellow stains.
    • Root exposure: Does not respond to bleaching.
    • Dentinogenesis imperfecta and amelogenesis imperfecta: No significant improvement with bleaching; better managed with periodontal coverage or final restorations; inherited dentin/enamel defects documented.
    • Microcracks: May respond but incisal edges may be less responsive; replacement strategies discussed.
    • Anterior lingual amalgams: Not to be bleached.
    • Dental caries: No significant improvement with bleaching.
    • Dark canines: Can become whiter than the rest of the tooth after bleaching.
    • Attrition: Bleaching may make affected areas more visible.
    • Aging: Some aging-related changes may not respond uniformly to bleaching.
    • Translucent teeth: Bleaching can increase translucency at the incisal edge; translucency considerations may affect aesthetic results.
    • Additional notes: Mention of tetracycline stain type (gray hue) and the possibility of periodontal coverage as an adjunct.

  • Issues Associated with Light-Activated Bleaching (Box 43-2)

    • Contraindications for light-activated bleaching:
    • Light-sensitive patients or those taking photosensitive medications.
    • Patients receiving photochemotherapeutic drugs or treatments (e.g., psoralen) or ultraviolet radiation.
    • Exposure to UV from lights should be avoided in patients at increased risk for skin cancer (including melanoma).

  • Indications for Tooth Bleaching and Methods of Treatment

    • General indications: cosmetic enhancement for discolored vital teeth.
    • Treatment methods: in-office, professional at-home bleaching, or combination approaches depending on stain type and patient needs.
    • Clinically relevant considerations: patient safety, sensitivity management, staining type, and restoration planning when color matching is essential.

  • Tetracycline Staining – Visual References

    • Figures 43.F02A and 43.F02B show before/after pictures of brown tetracycline-stained teeth treated with 10% carbamide peroxide for 2 months.
    • Important clinical note: Some tetracycline-stained teeth may require up to 12 months to achieve improved results; severe gray stain or banding may require porcelain veneers for an acceptable cosmetic result.
    • Images are courtesy of Dr. Van B. Haywood (D.M.D.), Professor, Dental College of Georgia.

  • Desensitization Procedures for Bleaching

    • Pre-treatment (2 weeks before bleaching):
    • Brush with a sensitive toothpaste containing potassium nitrate.
    • Use toothpaste with prescription-strength sodium fluoride.
    • During treatment:
    • Continue desensitizing toothpaste (sodium fluoride or potassium nitrate) daily between treatments.
    • Increase time intervals between bleaching treatments.
    • Reduce exposure time of bleaching materials.
    • Post-bleaching:
    • Continue daily desensitizing dentifrice.
    • Apply professional fluoride varnish as needed.
    • Avoid foods/beverages with extreme temperatures or acidic content to minimize sensitivity.

  • Comparisons of Modes of Tooth-Bleaching Systems

    • Different systems vary by activation method (e.g., light-activated vs. chemical), tray designs, and supervision level.
    • Choice depends on stain type, patient preference, sensitivity profile, and desired speed of whitening.

  • Tray Designs for Tooth Bleaching

    • Figure 43.F04A: Scalloped and unscalloped bleaching trays.
    • Scalloped trays protect gingiva and exposed root surfaces.
    • Unscalloped trays are more comfortable and require less preparation.
    • Important warning: patients should avoid overfilling trays.
    • Figure 43.F04B: Another depiction of scalloped vs unscalloped designs with similar cautions.

  • Professionally Monitored At-Home Bleaching Tray Treatment

    • Figure 43.F05: Depicts before and after treatment for at-home bleaching.
    • Note: Some tetracycline-stained teeth may require up to 12 months for improvement; in some cases, veneers may be needed for acceptable cosmetics.

  • At-Home vs In-Office Trays and Shade Assessment

    • Figure 43.F06A: Comparison of at-home bleaching trays.
    • Scalloped professionally dispensed trays vs OTC patient-made trays.
    • Professionally dispensed: fitted to the patient using impressions, casts, and flexible plastic for a custom fit.
    • OTC trays: bulkier and prepared by the patient at home.
    • Figure 43.F07A and 43.F07B: Manual selection of tooth shade
    • Shade taken, recorded, and photographed under appropriate lighting after extrinsic stain removal and before bleaching.
    • Shade tab ranges can be extensive (as many as 29 shades in some manufacturers).
    • Photo and shade are recorded at each bleaching visit.
    • Figure 43.F08: Digital photographic record of tooth shade
    • Electronic shade guides provide objective records.

  • Practical and Ethical Considerations

    • Set realistic expectations: some stains (notably gray tetracycline staining) may require long treatment times or adjunctive restorations (veneers, bonding).
    • Safety first: avoid light activation for photosensitive individuals; monitor sensitivity; follow desensitization protocols.
    • Restoration planning: communicate impact on shade matching with existing restorations; plan for final esthetics after color stabilization.
    • Real-world relevance: at-home systems offer convenience and cost savings but require patient compliance and careful tray design (scalloped vs unscalloped).

  • Quick references and typical values

    • Common bleaching agents and working times:
    • Hydrogen peroxide: begins to break down in ~30{-}60\;\text{minutes} and has a shorter working-time window per session.
    • Carbamide peroxide: slower release, higher pH, suitable for home use, with extended contact time.
    • Common treatment durations:
    • Nightly applications may range from 2{-}3\;\text{months} for some cases.
    • Daily bleaching regimens can extend to 3{-}6\;\text{months} for others.

  • Summary takeaways for exam readiness

    • Understand the biochemical basis of bleaching vs whitening and the role of chromogens.
    • Be able to categorize staining into extrinsic vs intrinsic and associate likely bleaching outcomes with stain type (yellow, nicotine, fluorosis, tetracycline, minocycline, etc.).
    • Recognize safety considerations, including light-activated bleaching contraindications and desensitization strategies.
    • Recall practical differences between tray designs, professional vs OTC products, and shade documentation methods (manual vs digital).
    • Be aware that certain conditions (e.g., root exposure, caries, amalgams, microcracks) influence bleaching response and treatment planning.

  • Connections to clinical practice

    • Bleaching is often a cosmetic adjunct rather than a definitive intervention; plan for color stabilization and possible restorative follow-up.
    • Documentation with shade guides and photographs supports treatment monitoring and patient communication.
    • Patient education on sensitivity management and seasonal timing (e.g., avoiding dehydration effects) improves outcomes and satisfaction.

  • Formulas and LaTeX references used in notes

    • Treatment durations and times represented where applicable:
    • 30{-}60\;\text{min} per HP session.
    • 2{-}3\;\text{months} (nightly) & 3{-}6\;\text{months} (daily)—illustrative ranges.
    • Concentrations mentioned in figures/options:
    • 10\% \text{ carbamide peroxide} (as in Fig. 43.F02A/B).

Note: The notes above consolidate content from the provided transcript, including the decision-making table, condition-specific responses, desensitization procedures, tray designs, shade assessment methods, and safety considerations related to light-activated bleaching. Figures are referenced to indicate typical visual or procedural content that accompanies the text (without reproducing the images themselves).