Teeth whitening

The color of teeth changes due to either external or internal factors. Foods, medications, and tobacco chemically affect dental plaque and produce pigments that penetrate through enamel cracks into the deeper enamel layers. As we age, enamel becomes thinner and its structure changes, which alters the way it refracts light. These changes lead over time to the so-called age-related darkening of teeth.

During tooth development, tetracycline treatment, excess fluoride, and certain systemic diseases such as porphyria and erythroblastosis fetalis can cause so-called intrinsic discoloration of teeth. The discoloration of a single tooth can be the result of dental trauma, where bleeding within the tooth causes a change in color.

Teeth whitening is part of cosmetic healthcare: people feel younger, healthier, and more attractive when otherwise healthy teeth are whitened. Chemical whitening is a simple and inexpensive procedure compared to veneers or crowns.

Whitening agents

The history of whitening is more than 100 years old. Hydrogen peroxide was first used in 1884, and it remains the active ingredient today in various concentrations (3%–38%) and combinations. The hydrogen peroxide molecule is small and easily penetrates enamel and dentin. Home whitening gels usually contain 10–20% carbamide peroxide, which breaks down into hydrogen peroxide and urea. Ten percent carbamide peroxide equals about 3% hydrogen peroxide.

Home whitening with trays

Home whitening is suitable for mild discoloration, such as age-related darkening. To use home whitening, you must first visit a dentist, where your teeth are cleaned, the shade is recorded to track results, and you are given instructions along with a package containing whitening trays. The duration of results varies individually and depends partly on diet. Retreatment is usually needed every 0.5–2 years.

The most common, though rare, side effects are tooth sensitivity to cold and gum irritation. In addition, tingling of the tongue and throat may occur. All side effects usually disappear within a few days after tray use is stopped.

Whitening agents are not recommended for smokers (especially home whitening), as acidic substances can increase the carcinogenic potential of compounds produced during smoking. Whitening is also generally not recommended for pregnant or breastfeeding women.

Nowadays, all whitening techniques are based on the same principle. The whitening effect comes from the whitening gel—most often hydrogen peroxide combined with other components. Additional factors such as light (LED/halogen lamps, lasers, plasma light, etc.) have been shown not to significantly affect the outcome of whitening. They are mainly product-specific features used to initiate or accelerate the process, often making it more cumbersome or expensive. Excess heat from light can be harmful to the tooth nerve due to temperature rise. Light-induced drying of the tooth may temporarily enhance results, but the effect fades after a short time. Chemically activated whitening gels are safe, equally effective, and generally the most cost-efficient option for whitening teeth.

At Lille Dental Clinic, we use products from Ultradent, one of the leading and most respected manufacturers of whitening agents.