Bleaching

History

ROMANS Polished teeth using urea (carbamide) from

Portugal

MIDDLE AGES Barbaric bleaching

Filed teeth with an iron grater Used Aqua fortis (contains nitric acid)

WESTLAKE (1895) Bleached teeth with high concentrations of

hydrogen peroxide (H202) mixed with ether Treatment method was first published in the

American Journal of Dental Science

ABBOT (1918) Used Superoxol (30% (H202) to bleach teeth

discolored by fluorosis

AMES (1937) Bleached teeth with 30% hydrogen peroxide (H202)

and ether along with a source heat Treatment lasted approximately 30 minutes and

sessions were repeated up to 25 times.

ZACK AND COHEN (1965) First to conduct a scientific evaluation on how the

effect of the source of the heat affected the pulpo RESULT: No pulp damage found

Later confirmed by NYBORG & BRANNSTROM (1970)

ARENS (1972) Tried to bleach tetracycline discolorations with

35% Superoxol at 10°c below the pain threshold

History: Home Bleaching

KLUSMIER (1895) Orthodontist from Fort Smith, Arkansas Examined the effect of Gly-Oxid (Marion) used by his young

patients for removable appliances Discovered teeth became brighter and lighter tetracycline

stain disappeared

WAGNER Periodontist, Colleague of Klusmier Used the method in adults Result: gingiva less inflamed and teeth appeared whiter

MUNRO (1968) Side effect of Carbamide peroxide in a splint: Teeth

became whiter

HAYWOOD (1988) Adopted the concept

HAYWOOD AND HEYMANN (1989) Developed a home bleaching technique (currently the

used standard of care)

HAYWOOD (1990) Bleached teeth with high concentrations of

hydrogen peroxide (H202) mixed with ether Treatment method was first published in the

American Journal of Dental Science

ABBOT (1918) Used Superoxol (30% (H202) to bleach teeth

discolored by fluorosis

COMMERCIAL PRODUCTS INTRODUCED TO THE MARKET:

1989 White & Brite by Omni Based on Munro’s findings First commercial bleaching agent for vital teeth Contains 10% carbamide peroxide

1991 Opalescence by Den-Mat 1992 Nite White by Discus Dental 1994 Platinum by Colgate

Scientific Studies

HAYWOOD (1990) Studied on extracted teeth which were bleached for 5 weeks Scanning electron microscope showed no changes Bleaching materials used did not affect the topography of the

enamel

YARBOROUGH (1991) Published a review on the effectiveness and safety of

bleaching 2 effective ways: Carbamide peroxide and Hydrogen peroxide Hydrogen peroxide 3 to 6 times faster than Carbamide

peroxide

MURCHISON (1992) Examined the effect of carbamide peroxide on

enamel Conclusion: short term application did not cause

any significant change to enamel

Generally, majority show that it is safe to bleach teeth with

10% carbamide peroxide

Side Effects of Bleaching Agent

1. CONTAINS PEROXIDES Enhances effects of other chemicals (ex. Cigarette

smoke) Tendency to change oral flora If done over a long time, C. Albicans can accumulate

and hypertrophy the papilla

2. POWER BLEACHING Changes the hard structure of the hard tooth structures Resulted in Pulpitis (on animals)

3. TEMPORARY HYPERSENSITIVITY Disappears in almost every case when bleaching is

interrupted Remineralize using toothpaste with fluoride

4. ETCHED GINGIVA Unprotected gingiva Damage is temporary and disappears after a few days

5. TOOTH HYPERSENSITIVITY Patients should not have their teeth bleached Higher risk for post-operative sensitivity

6. ROOT RESORPTION On non-vital teeth prepared internally Possible CROWN FRACTURE

7. REDUCED BONDING ABILITY Avoid bonding restorations directly after bleaching Allow 2 weeks to elapse before bonding restorations

8. NEED FOR SUPPLEMENTARY BLEACHING Bleaching will decrease in time due and resulting to

color changes (coffee, red wine, fruit juices, soda, etc) Done approximately 1 year after 1st bleaching

Review of Bleaching Methods

BLEACHING OF VITAL TEETH Chemicals are placed on enamel Also called External Bleaching Can only change enamel discoloraiton

BLEACHING OF NONVITAL TEETHChemicals placed in the pulp chamberAlso called Internal BleachingCoronal dentin is changed

IN – OFFICE BLEACHING Power Bleaching 33% H2O2 with light and heat Stronger chemicals used Enamel damage could occur For patients who want to achieve results very

quickly Mostly, 3 bleaching treatments required

HOME BLEACHINGAdvantages

Little time spent (dentist must have an assistant or hygienist with necessary qualifications)

Usually more affordable Patients can bleach

whenever they wish to No rubber dam required Takes longer = Safer

Disadvantages Patients must collaborate

actively- Not worn, no effect- Too much, hypersensitivity

Higher cost and longer treatment time (if patients prefer to have their bleaching by the dentist)

Longer time