NON-VITAL BLEACHING

WHAT IS BLEACHING:-• Bleaching is a procedure which involves lightening of the color of a tooth through the application of

a chemical agent to oxidize the organic pigmentation in the tooth.

HISTORY OF TOOTH BLEACHING

BLEACHING WAS FIRST DESCRIBED IN 1864 AND A VARIETY OF MEDICAMENTS SUCH AS CHLORIDE, SODIUM HYPOCHLORITE, SODIUM PERBORATE AND HYDROGEN PEROXIDE HAS BEEN USED, ALONE OR IN COMBINATION, WITH OR WITHOUT HEAT ACTIVATION.

Discolouration of anterior teeth – after R.C.T. Tetracycline stains (mild). Fluorosis. Discolouration due to ageing.

INDICATIONS:-

CONSTITUENTS OF BLEACHING GELS• Carbamide peroxide.•Hydrogen peroxide and sodium hydroxide. •Sodium perborate.• Thickening agent-carbopol or

carboxy polymethylene.

• Urea.• Surfactant and pigment

dispersants.• Preservatives.• Vehicle-glycerine and dentifrice.• Fluoride and 3 percent potassium

nitrate

MECHANISM OF BLEACHING

The mechanism is oxidation/reduction process called as “Redox process”.The active ingredient is hydrogen peroxide, an oxidizing agentIt diffuses through the organic matrix of enamel and dentinproduces free radicals, which are responsible for the bleaching process (oxidation)These free radicals open the highly pigmented carbon rings and converting them into chains, which are lighter in color

BLEACHING TECHNIQUE :- 1. FORNONVITAL TEETH (A). THERMOCATALYTIC IN-OFFICE BLEACHING. (B). WALKING BLEACH/INTRACORONAL

BLEACHING. (C). INSIDE/OUTSIDE BLEACHING. 2. FOR VITAL TEETH (A). HOME BLEACHING TECHNIQUE (B). IN-OFFICE BLEACHING.

BLEACHING OF NONVITAL TEETH1. THERMOCATALYTIC TECHNIQUE OF BLEACHING 1. Isolate the tooth to be bleached using rubber dam.2. Prepare the access cavity3. Place bleaching agent (30% to 35% superoxol

and sodium perborate separately or in combination) in the tooth chamber.

4. Heat the bleaching solution using light curing unit.

5. Repeat the procedure till the desired tooth colour is achieved.

6. Wash the tooth with water and seal the chamber using dry cotton and temporary restorations.

7. Recall the patient after 1-3 weeks and do the permanent restoration of tooth.

THERMOCATALYTIC IN-OFFICE BLEACHING

2. INTRACORONAL BLEACHING/WALKING BLEACH OF NONVITAL TEETH1. Take the radiographs to assess the quality of

obturation. If found unsatisfactory, retreatment should be done.2. Evaluate tooth color with shade guide.3. Isolate the tooth with rubber dam.4. Prepare the access cavity, remove the

coronal guttapercha, expose the dentin and clean the cavity.

5. Place mechanical barriers of 2 mm thick, preferably of glass ionomer cement, zinc phosphate, IRM, polycarboxylate cement on root canal filling material. The coronal height of barrier should protect the dentinal tubules.

6. Now mix sodium perborate with an inert liquid (saline or water) and place this paste into pulp chamber.

7. After removing the excess bleaching paste, place a temporary restoration over it.

8. Recall the patient after 1-2 weeks, repeat the treatment until desired shade is achieved.9. Restore access cavity with composite after 2 weeks.

Walking bleach

RECENT ADVANCEMENT:-3. INSIDE/OUTSIDE BLEACHING TECHNIQUE Synonyms:- Internal/External Bleaching, Modified Walking

Bleach Technique• This technique involves intracoronal bleaching technique along

with home bleaching technique. • This combination of bleaching treatment is helpful in treating

difficult stains.• PROCEDURES1. Isolate the tooth and prepare the access cavity by removing gutta-percha 2-3 mm below the cementoenamel junction.2. Place the mechanical barrier, clean the access cavity and place a cotton pellet in the chamber to avoid food packing into it.

3. Evaluate the shade of tooth.4. Check the fitting of bleaching tray and advise the patient to remove the cotton pellet before bleaching.5. After bleaching, tooth is irrigated with water, cleaned and again a cotton pellet is placed in the empty space.6. Re-assessment of shade is done after 4-7 days.7. When the desired shade is achieved, seal the access cavity initially with temporary restoration and finally with composite restoration after at least two weeks.

INSIDE/OUTSIDE BLEACHING

Precautions should be taken for Safer Nonvital Bleaching

1. Isolate tooth effectively. 2. Protect oral mucosa. 3. Verify adequate endodontic obturation. 4. Use protective barriers. 5. Avoid acid etching. 6. Avoid strong oxidizers. 7. Avoid heat. 8. Recall periodically.

NONVITAL BLEACHING ADVANTAGESLow costHigh success rateNo tooth alternationNONVITAL BLEACHING DISADVANTAGESUnpredictable resultsNeed Re-treatmentPossible side effects

Bleaching is safe, economical, conservative and effective method of discoloring the stained teeth. It should always be given a thought before going

for more invasive procedure like veneering or full ceramic coverage,

depending upon specific case.

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