Dental bleaching, also known as tooth whitening, is a common procedure in
                                        general dentistry. As a person ages the adult teeth often become darker due to
                                        changes in the mineral structure of the tooth, as the enamel becomes less
                                        porous. Teeth can also become stained by bacterial pigments, foodstuffs and
                                        tobacco. whitening is done with bleaching gel such as hydrogen peroxide or
                                        carbamide peroxide which is applied to the teeth using thin guard trays to
                                        lighten the shade of the tooth. 
                                        
The effects of bleaching can last for several months but may vary depending
                                        on the lifestyle of the patient. Factors which will decrease whitening include
                                        smoking and the ingestion of dark colored liquids like coffee, tea and red
                                        wine. 
                                    
                                    click