Teeth can become discolored for many reasons. Teeth damaged by trauma (injury) can turn yellowish as a consequence of excessive calcification. Disturbances of the enamel formation can be triggered by many diseases (e.g., amelogenesis imperfecta, vitamin D or C deficiency) or by an excess of fluoride in drinking water or food. Caries, eating habits or simply age are some of the most common and important causes of discoloration.
Hereditary diseases (e.g., dentinogenesis imperfecta, or osteogenesis imperfecta) can cause extensive discoloration because dentin is not formed properly. Antibiotics like tetracycline, if taken during childhood when teeth are mineralizing, can cause a characteristic blueish-grey or yellowish-brown discoloration.
Non-vital or root-canal treated teeth often show a darker color and are less translucent. Because the exact cause of discoloration can significantly affect the result of the bleaching it is important that the dentist takes an extensive medical and dental history before bleaching.
Hypersensitivity would strongly indicate that bleaching should not be carried out!
- Appropriate for root-canal treated teeth
- A bleaching agent (e.g., sodium perborate mixed with hydrogen peroxide or with water) is applied to the former crown’s pulp for about one week, after application of a cement barrier (about 2mm under the gums)
- Calcium hydroxide dressing for about 2 weeks before the tooth is treated with an adhesive filling
- Repetition of bleaching after 1-3 years often necessary
- Improper treatment can lead to root-resorption, where the body’s own cells eat away and dissolve tooth structure
- Appropriate for vital teeth
- Application of the bleaching-agent (10% carbamide peroxide gel) using an individually made occlusal splint which the patient wears at night
- Treatment takes longer (4-6 weeks)
- Regular check-ups at the dentist are required
- An alternative to bleaching
- Involves the removal of about 25 microns of the enamel surface
- Appropriate where white or brown spots, or rough places are on the tooth’s surface
- The enamel surface is treated for 10 seconds with a gel made of diluted hydrochloric acid and pumice using a rubber polishing cup
- The procedure can be repeated as needed
- The tooth is subsequently rinsed with water and neutralized with sodium bicarbonate, then washed with water again and polished with a polishing fluoride-paste