Given the range of composites that exist in the dental market, many dentists have not yet found their ideal composite for each case. From Dentaltix, we want to help you with a list of the most frequent questions in dentistry, about the world of dental composites. In the choice of a composite there are many factors that can be key to achieving success in a good dental filling or restoration: The location of the dental cavity, aesthetic requirements and whether the restorations are anterior or posterior, etc.
Why does the size of the composite filler particles matter?
In the world of composites, particle size matters a lot. Depending on the filler particle size, we find the following types of dental composite:
The first dental composites that were used in dentistry were determined by their macro filling. They are so called because their size was 15 to 100 micrometers. On the other hand, nowadays, simple particles of 2 micrometers are considered macroparticles. These composites were very resistant, but their surface roughness, difficult polishing and poor clinical performance limited their use until they became obsolete. Fortunately, to deal with this aesthetic issue, microfiller composites soon emerged.
These composites have a more appropriate particle size: 0.4 micrometers. Their reduction, together with their natural translucency and high degree of polish, make for exceptional aesthetics. However, they are limited to the anterior sector, where the masticatory stresses are lower than those of the posterior sector. A good example of microrfilled composite is Heliomolar from Ivoclar Vivadent, available in syringe , capsules or in fluid composite
Another type of dental composite is the hybrid, characterized by mixing different sizes in its composition, this offers the best of both in dental resins. Hybrid composites can be described as small particle macro-fill composites (0.6 - 5 micrometers), with a microfiller of 0.04 micrometers incorporated into the resin matrix. This combination of particles improves the transfer of tension between particles, conferring unique and superior properties. These microhybrids are universal composites, and can be used in both anterior and posterior restorations, thanks to their impressive combination of strength and polishability, wear and fracture resistance, and versatile clinical handling. An example of a microhybrid composite with a very high degree of polish and strength is Ultradent's Amelogen Plus., available in a 2.5 gram.
The nanorelleno is one of the most advanced choices in the field of dentistry. Nanotechnology has made it even more possible to reduce filler particles to nanometric dimensions. Composites formed by nanoparticles have exponentially improved their mechanical and aesthetic properties, such as abrasion resistance, surface smoothness, and the final finish result. An example of this composite is Voco's Grandio. This composite, available in a syringe, consists of nanoparticles between 25 and 60 nm and particles with an average size of 0.7 microns.
What tone range is available?
The composite is a synthetic material that adheres to the tooth surface for a perfect filling of the tooth. However, emulating the natural dentition to achieve an imperceptible restoration and great aesthetics, and adapt the colour through three aspects: tone , saturation and value, are other main objectives. Tonality or hue is the name of the colour, i.e. the specific type of wavelength. Today, most resinous systems use the classification Vita to identify shades. In it we can find four classical shades:
- A. Brown - Reddish. 80% of patients
- B. Orange - Yellow
- C. Grey - greenish
- D. Grey - Pink. Corresponding to 5% of people, and used more specifically for characterizations.
The tone of the dentine which is to be considered basic among the dentin elements, is recorded at the level of the central part of the vestibular cervical third. This is where the least amount of enamel can be found, but a large volume of dentine can be found. On the other hand, the shade of the enamel should be recognized at the level of the middle third of the teeth, where it is generally two or three shades lighter than the one chosen for the dentine.
What to take into account in composite polymerization?
There are a lot of factors that can alter a good polymerization , and therefore, the final result of dental restorations. One of them is the time we dedicate to it, this varies according to the colour of the composite, the power of the lamp, the depth of the cavity, the thickness of the layer, the interposed dental structures or the quantity of the filling material itself.
- The colour of the composite. Darker shades require longer polymerization time, about 60 seconds at maximum depth of 0.5 mm.
- A composite at room temperature polymerizes in less time and faster
- The layer thickness of the resins is very important. It is recommended not to polymerize layers with a thickness greater than 2 mm.
- The type of fill, for example, microfines polymerize worse than those with higher loads.
- The distance between the light bulb and the composite . The most optimal distance is greater than 1 mm with the light perpendicular to the material.
The contraction of the composite in the polymerization process
In treatment of dental composites it is very important to take into account certain situations that can be the cause of many of the problems when polymerizing. The hardening process of a polymer always occurs by the bonding of molecules that will bind and then occupy a smaller volume than the initial one. Dental resins need to be polymerized to obtain their properties. The more the composite material is polymerized, the better properties it achieves, but at the same time and to the detriment of the above, the more it undergoes this process, the more it will contract. The more it contracts, the greater the tension the adhered surfaces will be subjected to. Shrinkage cannot be totally avoided in the polymerization process of dental composites, but if we have these clear tips, we will get reduce it .
- Use dental composites with a restorvie system based on silorane. The silorane is an experimental hydrophobic resin of 3M ESPE, which rises from the combination of two basic chemical compoents, siloxanes and oxiranes. Its application will cause a significantly lower volumetric shrinkage.
- Nanotechnology. Nanofillers incorporate ceramics. The application of ceramics in the filling composition of dental composites reduces shrinkage considerably without losing the handling characteristics of the material. An example is the nanocomposite Filtek Supreme XTE from 3M ESPE
- Using dental resins composed of Ormocer is another advantage to decrease contraction. Ormocer is a much larger molecule than the conventional bis - GMA, the main component of most existing composites. However, the introduction of ormocer in the DNA of the dental composite has meant that its application has achieved an exponential improvement in the final result, since the percentage of contraction is significantly low. The set of Admira Fusion of the Voco brand is mainly composed of Ormocer and presents incredible results.
Like fish in the sea, there is one composite for each type of treatment. To find out which one is right for you, you just have to be up to date with all the important features and factors in its application. We hope that, from Dentaltix, we have helped you to resolve the most frequent doubts and you have acquired a better vision of the composite. If you still don't have it completely clear, you can consult in our blog article the dental composites guide: Main types and applications.