Medical devices

Composite – Application & Health Benefits


Composite or composites are filling materials from the dental practice. They are used to place fillings, attach crowns and root posts and carry out ceramic improvements. The materials are mostly used in the front tooth area . However, there are now substances with a higher filler content that can also be used for posterior teeth.

What is composite?

Composite has almost completely replaced the amalgam filling that was common in the past, since amalgam is said to pose health risks due to its mercury content .

Composites consist of several high-tech composite materials. The main part of about 80 percent consists of ceramic, glass and quartz particles. Only 20 percent make up the actual plastic content. As a result, the filling material has gained in stability.

In contrast to amalgam fillings, composite fillings are not stuffed, but applied and glued in layers. Thanks to the nature of modern composites, they can withstand high mechanical loads and are very abrasion-resistant. On average, a composite filling lasts at least seven years.

Shapes, Species & Types

The material from which the composites are made is based on plastics that originate from an acrylic base. These include BisGMA, TEGMA, EGDMA, UDMA and methacrylate. It may also contain traces of acids, formaldehyde and glutaraldehyde. Particles of glass, quartz and ceramics are used as fillers. Silanes improve the coating with the plastics.

There are three types of composites. The conventional composites with large fillers, also called macro fillers. They are made of quartz, glass or ceramic with a size of one micron. There are also micro-filler composites with the finest micro-fillers. They are made of silicon dioxide ranging in size from 0.01 to 0.04 microns. The third variant is the hybrid composite, which consists of both micro-fillers and macro-fillers. These state-of-the-art composites contain between 85 and 90 percent macrofillers, with the remainder being microfillers. This combination ensures increased packing density.

There are further subdivisions for the hybrid composites. There are hybrid composites with an average filler of up to ten microns. There are also fine particle hybrid composites with a filler size of up to five microns, followed by the finest particle hybrid composites with a filler size of up to three microns and finally the submicron hybrid composites with a filler size of less than one micron.

Structure & functionality

The first generation of composites was based on a combination of paste and liquid. This type of polymerization has proven to be disadvantageous in several respects. Layer application was not possible with this combination, the curing time could not be controlled and the plastics were not color stable. That is why there are light-curing composites today.

The curing process is started with the curing light, which emits blue light. This cold light source with a specific wavelength stimulates a chemical process that starts curing. A major advantage of the light-curing variant is the higher degree of curing and the significantly better color stability, which is particularly important in the front tooth area. In addition, the materials can be processed and modeled for as long as is necessary for the respective individual case. The application of several layers is also possible. Only the targeted use of light sets the final curing in motion.

If treatment with light-curing composites is not possible, which is often the case with opaque materials such as those used in partial and full crowns or ceramic inlays , dual-curing composites can be used. Only the edge areas are cured with the polymerization lamp. Chemical polymerisation is then used on the areas inaccessible to light.

Medical & health benefits

Composite fillings can be done in one visit without the help of a dental laboratory. Once the decay has been removed by the dentist , the tooth is restored layer by layer. The various natural color gradations make a lifelike reconstruction possible, so that after polishing the filling can hardly be distinguished from the actual tooth structure.

The advantages compared to earlier amalgam fillings are not only health benefits, but also better stabilization of the tooth and color. However, plastic fillings are more complex than amalgam fillings, since the composites have to be applied in several layers and hardened in layers.

Compared to ceramic fillings, composite fillings have the advantage of being cheaper and less time-consuming, since impressions are required for ceramic fillings. The number of plastic fillings is increasing because amalgam fillings are considered to be harmful to health.

In the meantime, however, a possible problematic effect of the composites is also being discussed. Assumptions are made regarding toxicity, mutagenicity, estrogenicity and allergies caused by the composites. However, apart from allergies, nothing of the sort has been proven in studies so far.

The plastics BisGMA and UDMA are not mutagenic in their cell cultures, unlike TEGDMA, where mutagenicity has been demonstrated in cell cultures. However, it requires a very high concentration, which is not the case with tooth fillings. An estrogenic effect could also not be demonstrated. Although BisGMA contains bisphenol A, which develops a pseudoestrogenic effect, this has not yet been proven in the mouth area.

Lisa Newlon
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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.