COLOUR OF NATURAL HEALTHY TEETH


  • Teeth are composed of a surface enamel layer, which is whiter and semitransparent, and an underlying dentin layer, which is darker and less transparent.
  • The colour of teeth varies among the gum, tip and central areas according to the thickness, reflectance of different colours and translucency in enamel and dentin.
  • The colour of healthy teeth is primarily determined by the dentin and is modified by:

           1. The colour of the enamel

           2. The translucency of the enamel

           3. The thickness of the enamel.

TOOTH STAINS

Stained teeth
  1. Tooth stains are one of the most common problems. People of various ages may be affected, and it can occur in both primary (milk) and secondary (permanent) teeth.
  2. The cause of tooth stains is due to various factors, & different parts of the tooth can take up different types of stains.

TYPES OF STAINS

  • There are two types of stains: extrinsic or intrinsic.
  • Extrinsic- occurs when an external agent stains or damages the enamel surface of teeth. Can be easily removed by prophylaxis (tooth cleaning).
  • Intrinsic- occurs when internal tooth structure is penetrated by a discoloring agent. These stains cannot be removed by prophylaxis, some of them can be removed by bleaching.

CAUSES OF TOOTH STAINS

Extrinsic stains

  • Plaque
  • Calculus (tartar)
  • Bacteria
  • Smoking
  • Tobacco and tobacco products
  • Betel nut (supari)
  • Mouthwashes, e.g. chlorhexidine,
  • Beverages (tea, coffee, red wine, cola)
  • Foods (curry, cooking oils and fried foods, foods with colorings, berries, beetroot)
  • Dietary precipitate
  • Antibiotics (erythromycin, amoxicillins)
  • Iron supplements

Intrinsic stains 

  • Disease:

        - Haematological diseases

        - Liver diseases

        - Diseases of enamel and dentin

  • Medication:

        - Tetracycline stains

        - Other antibiotics use

  • Trauma
  • Primary and secondary decay
  • Dental restorative materials
  • Ageing
  • Chemicals
  • Fluorosis

BLEACHING TECHNIQUES

  1. Home bleaching
  2. In-Office bleaching

HOME BLEACHING TECHNIQUE

Home bleaching involves getting a set of bleaching trays made for your teeth from your dentist, and then applying bleach into those trays to whiten your teeth.

Home bleach tray

ADVANTAGES

  • Simple method and easy to use for patient
  • Less time in dental clinic
  • Cost effective

DISADVANTAGES

  • Depends on patient compliance
  • Color change depends on amount of time the tray is worn by patient
  • Excessive wearing of tray may lead to sensitivity
  • Results may be unpredictable
  • Day time use can enable the patient to replenish the solution after every 1-2 hrs
  • It takes a long time before achieving satisfactory results

SIDE EFFECTS

  • Gum irritation: either due to leakage of bleaching material from the margins of the tray or excessive wearing or applying too much bleach on the tray

  • Metallic taste after removing the tray
  • Sensitive teeth

IN-OFFICE BLEACHING

In-office bleach involves application of bleaching material and careful monitoring by the dentist in the clinic. Sometimes the bleaching can be accelerated by external photo-activated method like LED’s, lasers, mercury halide lamps, plasma arc, quartz halogen or ultraviolet units. Incorporation of light-activated technology has reduced the treatment time.

In-office bleach
Light activated in-office bleach

ADVANTAGES

  • Easy for dentists to monitor as the whole process is done in clinic
  • Color change is uniform and predictable
  • Faster and visible results
  • Results are long lasting as compared to home bleach technique

DISADVANTAGES

  • More time in dental clinic
  • Not as cost effective as home bleach technique