Teeth whitening is a dental aesthetic procedure used to try to recover the natural color of the teeth. To perform an external tooth whitening, molds are first taken from the patient’s mouth. From these molds a transparent splint of soft acrylic is made in the shape of horseshoe that has engraved the fingerprints of the teeth to adapt perfectly to them. This serves as a vehicle to apply a whitening gel to the teeth. This bleaching product can have different compositions depending on the degree of tooth whitening needed to achieve.