• Pregnancy and breastfeeding;
• Bronchial asthma;
• "Tetracycline teeth" - gray spots on teeth;
• Hyperplasia - white stripes on the teeth;
• Age up to 16 years - teeth tissue is not yet fully formed;
• wearing braces - whitening will be uneven;
• Presence of an exposed tooth neck, erosion;
• Significant decrease in enamel as a result of pathological or age-related abrasion, deep cracks on the enamel surface.
• Periodontal disease;
• Caries. Before whiten, you need to brush your teeth;
• The presence of denture of the front teeth. After teeth whitening, the difference in the color of the whitened teeth and crowns may be different because the crowns were matched to the teeth before whitening.