Teeth whitening: the progress of the past 25 years

Teeth whitening as a dental procedure began to gain popularity after the publication of the article "Aligners for bleaching" Van Haywood and Harald Heymann, published in the year 1989, in which the author describes the technique of home whitening, providing long-term and the best result of this therapeutic intervention. Further research of many authors proved the effectiveness and safety of teeth whitening procedures, such as reducing the risk of complications, since the Protocol of this intervention over the years, more and more modificeres, and the handling to be more clinically controlled. Therefore, in this article we will discuss how it has changed approaches to whiten your teeth during the last quarter of a century from the point of view of research, clinical observations and experimental evidence.


Even with 25 years of history, as a particular teeth whitening service continues to gain more and more popularity among patients due to the constant improvement of the techniques used in the course of the procedure of materials (Greenwall, 2001). In 1880 a high concentration of hydrogen peroxide is used to make the smile more expressive, in our time – to this effect a special night splints, which can be completely safe to use at home.

History of the popularity of aligners for bleaching were quite interesting: the dentist the American Bill Klausmier in 1968 will be recommended to your patients to fill the night splints-retainers, with a solution of peroxide in order to reduce the amount of hyperplasia gingival (Haywood, 1991a), and what was his surprise when, six months later, she began to notice that not only the patients gums look much better, but his teeth were noticeably whiter. This accidental discovery, as in his time, and the discovery of penicillin has allowed many patients to achieve the desired aesthetic result of the correction of their smile without any major interventions.

Forty years Klausmier continues to claim that in his practice none of his patients do not need treatment dental as a result of bleaching and a method of evening applications of the peroxide with the use of Kappa is one of the most safe variants of the procedure. Currently Klausmier deliver the responsibility to carry out studies of the effects of the procedure of bleaching Van Haywood, something that makes this day.

Early studies

The first studies of several aspects of treatment were more focused on the study of the safety and efficacy of this manipulation. Professor Yiming Li of Loma Linda University, who has spent the last 20 years of his life devoted to the study of peroxide as a bleaching agent, came to the conclusion unequivocally that the compound is chemically safe substance to oral tissues, if the use of the same is controlled by the treating dentist (You, Greenwall, 2013).

In the 1990s, the issue of money laundering was involved in a large number of researchers, and therefore the number of publications on different aspects of this procedure, in addition to a few thousand euros. During the research advanced, on the question of sensitivity, characteristics which are observed in 85% of patients after the treatment, it was found that very important is the application time of the chemical agent and the pulp of the tooth, in which the procedure is carried out. Therefore, the vital importance of teeth, the application of the chemical agent can be carried out at from 5 to 15 minutes, while bleaching requires mandatory prior endodontic treatment.

Methods whitening

There are two main types of whitening procedures:

  • the night through carbamide peroxide.
  • day by means of hydrogen peroxide.
How has the principles?

Guidelines for the money laundering was introduced in 2011 in the structure of the safety Regulations of the use of beauty products of 2012 (Directive 2011/84/EU supplements Directive 75/768/ESA), which came into force in October 2012. According to this normative document, the use of products that contain from 0.1% to 6% of hydrogen peroxide, is prohibited between persons under the age of 18 years, if this is not aimed at the prevention and the treatment of any disease or disorder. At the same time, products that contain less than 0.1% of hydrogen peroxide, such as oral rinses, and bleaching agents are completely safe to use and free disposal in the commercial.

Dental products containing hydrogen peroxide in the amount of 0.1 – 6% can only be used with careful clinical monitoring, taking into account all the possible risk factors for the emergence of specific pathologies and complications. In addition, the use of agents for bleaching should be limited in frequency and in time, and since the control of the same is difficult, these chemical agents should not be directly available to the immediate buyer. These substances may only be carried out in the course of dental treatments, and only as directed by your doctor, who will monitor the effect of this procedure in each of the repeated visits of the patient. In addition, the first use of this type of products must take place under the direct supervision of a dentist, which you can later adjust the algorithm performs this procedure for the patient and carefully explain all the important aspects of this type of manipulation.

The use of products that contains peroxide, the concentration of which is about 6%, is strictly prohibited, if this does not provide for preventative or therapeutic purposes. Anyway, dentists, according to the rules, it is forbidden to assign patients, any substance used for bleaching, hydrogen peroxide concentrations above 6%.

Whitening a single tooth dark

Approaches for bleaching vital teeth and the other has changed significantly over the past 25 years to improve this procedure have increased the expectations of patients, to popularise the maximum white color of the teeth, despite the complexity of some procedures disappeared any age restriction of the procedure, and some people have even begun to develop a pathological obsession with whitening. However, he changed the focus of the use of the full and segmented Kapp as different algorithms therapeutic bleaching with the use of different gels, wet agents (potassium nitrate), solutions of different concentrations, the effect of the ozone treatment or even laser technology.

Today for whitening a single tooth can be used segmented Kappa, but before carrying out this manipulation it is important to evaluate properly the whitening potential and opportunities of the problematic tooth. In the first place, we need to provide the conditions in which the use of mouth guards will ensure the realization of the whitening from the first to the part affected, and then the adjacent; if you do not adhere to this principle – a dark tooth in the background partially bleached adjacent will be even worse.

Whitening single tooth

In the case of injury to the tooth structure begins with the deposition of secondary and tertiary dentin, bleeding in the pulp space, and also the deposition of iron in the formed blood clot – all of this leads to a change of the crown in one or two tones in comparison with the adjacent normal teeth. In the past it was believed that these teeth go through the process of conversion of calcium, and, therefore, require the prior endodontic treatment (Haywood, 2010). But as it turned out, and bleaching may be sufficient to achieve a suitable aesthetic smile profile.

Special teeth

The standard technique, called step-by-step, bleaching and developed by Nutting and Poe in the year 1965, in our time, few have been modified and now involves the combined use of sodium and 35% solution of hydrogen peroxide. These two substances are not the best action, the force is equal to the action of 50% peroxide, which is too aggressive a drug, in contrast to offer a mixture of chemical agents. According to the European standards, the use of hydrogen peroxide with a concentration of more than 6% it is prohibited, especially if the treatment is planned in the area of the tooth with an injury history – in this case, significantly increases the risk of cervical resorption, are widely described in the literature (Cvek, Lindwall, 1985; Hierthersay 1999).

New protocols require bleaching using aligners for bleaching of different design – full and partial: 16% solution of carbamide peroxide is placed in the space of the root canal, while the patient, in this case, wearing a mouthguard for bleaching, thus, the process of tooth restoration is done both to the exterior and the interior. William Liebenberg in 1997 even offered to keep the access cavity in the tooth open in order for the patient by using the syringe to establish a bleaching agent in the space of the root canal for weeks. After that, the patient returned to the dentist, who did a complete cleaning of the camera and its recovery by means of special cement.


Future Perspectives: the whitening varnish

A new direction in the improvement of the procedures for teeth whitening is using whitening varnish containing 6% solution of hydrogen peroxide. Due to the property of this product, it is very well connected with the tooth and ensures the direct delivery of the active chemical agent in the tissue of the enamel and dentin. After the application of the active substance on the surface of the teeth, in addition, cause more hydrophobic layer of silane, which helps to keep the peroxide in place. After 30 minutes or an hour to the whole substance is removed from the tooth surface by brushing with a toothbrush. In addition, it continues to develop the enzymatic approach to restore the color of the teeth, with the mixture of two different agents for the treatment of carbamide peroxide and lactoperoxidase, which provides for activation of the bleaching chemical agent.

In the long-term whitening effect

According to studies, if you adhere strictly to the Protocol of treatment, the effect can be stable for 17 years. However, the majority of patients often repeat this procedure every 3 years. When it reaches the maximum whitening potential of the teeth, during the re-intervention rate, in general, takes a very short period of time – ranging from 3 to 7 days.

Whitening for life

After the first treatment, it is expected that the patient will periodically repeat this procedure in order to preserve the maximum white of the teeth. With an average of 25 years of life of the patient, it is not recommended more than 4-5 of these whitening procedures with the obligation of periodic carrying out professional hygiene of the oral cavity and other preventive measures, the use of whitening toothpaste and limiting the food and drinks that contain harsh dyes.

Obsession with teeth whitening, or bleachorexia

During the last 25 years it has been possible to whiten your teeth to shades that are not even characteristic of the classical dial-color Vita. Therefore, the market appeared new models from the standard white color, and for a comparison of the results of treatment, as well as the selection of certain types of ceramics or composites during dental treatment. Some patients in the confusion of the General popularity in the procedures of bleaching can develop the syndrome of bleachorexia (Kelleher, 2014), or a pathological obsession with whitening the teeth, often associated with several disorders and low self-esteem. Every dentist should be able to identify these patients, including their patients. One of the main symptoms of the obsession with teeth whitening is its shade, which they seem to be more white that the scelera of their own eyes, which often is positioned as the most reference of white color. These patients need to persuade in the absence of the need for re-treatment, and keep them relevant explanatory work.