Two-component glue is familiar to most people from everyday life. With this, a wide variety of things can be glued together in a flash and very firmly. But two-component adhesives also exist in dentistry.
What is a two-component adhesive?
Two-component adhesives also exist in dentistry. Two-component adhesives, also called two-component adhesives or 2K adhesives, belong to the so-called chemically setting adhesives (also called reaction adhesives). In dentistry, too, two-component adhesives are similar in principle to the adhesives we know from other areas – at least when it comes to the pure adhesive function. Here, too, two components are used, each of which is applied separately to the various parts that are to be bonded together. When these parts are finally joined together, and the two different components come together, they bond in a flash – often within seconds. However, in this case we are dealing with an adhesive that is made specifically for use in the mouth area. This is because the two-component adhesive for dentistry is required to be different from adhesives that are used in the home, for example.
Forms, types and grades
As with ordinary two-component adhesives, there are also different types of adhesives in the field of dental adhesives. These differ not so much in their basic composition, but in their mode of action. Experts in the overarching field of two-component adhesives speak of polymerization adhesives, for example, when polymerization (the synthesis that joins the substances together) is triggered by a reaction with a catalyst. Polyaddition adhesives, on the other hand, refer to compositions that mix two chemically different but stoichiometric and reactive substances. These combine with each other when they come into contact. Polycondensation adhesives, on the other hand, refer to compositions that react and bond together when pressed against each other (for example, by releasing condensates such as gas molecules). Due to the different compositions and also the different advantages and disadvantages, in case of doubt it must also be assessed in dentistry which type of adhesive and which composition is correct in the individual case. However, although there are also various types of two-component adhesives in the dental field, one type is mainly used today because it has often proved its worth. In dentistry, the cyanoacrylate adhesive system is usually used for two-component adhesives. This also makes use of the polymerization reaction that occurs when the ingredient cyanoacrylate reacts with the adhesive polymer used. Adhesives for dental use are also available in different viscosities and also setting times. That is, they come in thin, medium and thick flowing, and they cure more or less quickly depending on the design.
Structure and mode of operation
Two-component adhesives belong to the so-called chemically setting adhesives, which are also called reaction adhesives. These adhesives consist of two components that bond together when they come into contact. How quickly they form the bond depends on the individual components. In most cases, however, the bonding process is completely finished within a few seconds. As a rule, 2K adhesives consist of a resin that acts as the binder. Epoxy resins or acrylate resins are usually used for this purpose. To this is now added a catalyst, also called a hardener. In addition, substances can be added to accelerate the curing process or stabilize the result. Here, it depends on the composition of the adhesive. Basically, two-component adhesives for dentistry may not differ significantly from other two-component adhesives. For this reason, the compositions of most adhesives closely resemble those of adhesives used in other fields. Moreover, the cyanoacrylate adhesive system is not only in demand in the field of dentistry. However, adhesives used here have to meet some special requirements. For example, they must be as harmless as possible to the human body. After all, the dental prosthesis, partial denture or similar on which the adhesive has been used should be able to be reinserted in the mouth as quickly as possible (sometimes even immediately after bonding) without any concerns.However, not all adhesives meet this requirement. Some pollutants must first be neutralized with special substances. Depending on the type of pollutant, this can take a few minutes but also several hours.
Medical and health benefits
Suitable two-component adhesives can be used in dentistry to bond materials such as plaster, ceramic, plastic or metal, among others. So far, so good, because so can other adhesives, such as ordinary superglues, which were developed for or, by their nature, can be used in dentistry. However, the greatest advantage of the two-component adhesive for dentistry is the comparatively lower material consumption. This is supported, for example, by special applicators with which the two components of the adhesive can be applied very precisely. Since the curing process of the 2-component adhesive does not begin until the two components come together, the dentist or dental technician in charge can – unlike with ordinary instant adhesive – take the necessary care when applying the adhesive. This makes it possible, for example, to prevent the adhesive from reaching places where it should not. Today, it is possible to very specifically prevent holes from being glued or the adhesive from spreading into bulges. In the case of dentures, for example, this would have a negative impact on the patient’s wearing experience. What’s more, some bonds provide a stronger and more stable adhesive result than ordinary instant adhesives, which are also used in dentistry.
