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 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.
- 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
- Calculus (tartar)
- 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
- Haematological diseases
- Liver diseases
- Diseases of enamel and dentin
- Tetracycline stains
- Other antibiotics use
- Primary and secondary decay
- Dental restorative materials
- Home bleaching
- 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.
- Simple method and easy to use for patient
- Less time in dental clinic
- Cost effective
- 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
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 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.
- 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
- More time in dental clinic
- Not as cost effective as home bleach technique