People are often insecure about the colour and appearance of their teeth, and the appearance of their smile is very important to them. The colour of the teeth has a great psychological and social impact on people and influences the opinion about one's own appearance. Whitening with gels in splints is one of the most requested aesthetic procedures among patients today. There is a difference in tooth colour assessment between the dentist and the patient, so patients perceive their teeth as darker than their dentists. We are witnessing an increasing general influence of social networks and thus their influence on people’s general appearance and the appearance of their teeth. For this reason, there is a growing number of patients with unrealistic expectations. It should be defined more clearly what the patient can expect from each procedure in order to avoid possible inconveniences after the procedure has been completed. The objective of this work is to perform a two-week at-home whitening of natural teeth using a splint and 16% carbamide peroxide, thereby photographing the changes and measuring the whitening index on a weekly basis. A digital protocol for monitoring the colour change during the whitening procedure is assumed to help improve communication between the dentist and the patient.