Behind the bleaching: chemistry and mechanics of teeth whitening agents and their effects on tooth surface

During a verbal interaction with another person, the gaze focuses at eye level and at that of the lower third of the interlocutor’s face. Therefore, the smile is an important verbal and non-verbal communication tool, other than having a major social impact and contributing to an image of order and cleaniness. Dental aesthetic appearance is related to cultural factors and different personal preferences, i.e. visual perception may be pleasant or unpleasant, and what is considered ‘beautiful’ in one country may be ‘ugly’ in another. With the rise of social networks, people pay more attention to their image. Also, aesthetic treatments have increased considerably in recent years. Dental discolouration is a major aesthetic problem and, consequently, 'cosmetic dentistry’ is an increasingly popular discipline in modern dental practice. It is crucial for the practitioner to try to perform these treatments in the least invasive way possible. Therefore, this requires us to be fully aware of everything that goes on behind the scenes of a tooth whitening procedure: chemistry, interaction with dental tissue, mechanical properties of teeth, etc.