7 Types Of Composite You Should Know (FOR DENTAL PROFESSIONALS)
Today we’re going to talk about seven different types of composite that you should know. So, why should you know these seven different types of dental composite? Well, if you’re a general dentist and you’re doing restorative dentistry on a regular basis you’re really the subject matter expert for restorative dentistry so nobody should know these materials better than you and I’m a firm believer that if you understand why you do things and you understand the materials that you use it’s gonna be to your advantage in the clinic on a regular basis. You’re gonna be able to make good sound clinical decisions because you understand the materials and how to use them.
Alright before we talk about the different types of composites I want you to know we need to discuss some components. Now typically composites are comprised of four major components. I am only going to mention two of those components here today. Those components are a resin matrix and filler. Now when you have a composite that has a high filler content it’s gonna have better properties. It’s gonna have better physical properties and better mechanical properties. Typically we’re gonna think of it being stronger if you have a composite that has a very high resin matrix and low filler content. We’re typically talking about a product that usually has lower physical properties, lower mechanical properties, and increased polymerization shrinkage. There are many ways that you can classify composites and if you look at all the composites that are on the market there are a lot of ways that you could categorize these composites. Some of the ways that you may see composites categorize are based on the particle type or the filler type. That’s typically the way I like to look at composites and you’ll see and understand why shortly.
Other ways that you can categorize composites are based on the monomer. Remember the resin matrix contains a monomer and depending on what the monomer is in that matrix you could have monomers that are more traditional-based monomers and now there are a lot of monomers on the market that are low shrinkage monomers. They’re basically designed to minimize the shrinkage of the composites when it’s polymerized.
Now you could also classify them based on the viscosity where you have paste composites and you have flowable based composites. They basically are handled in different ways and so that could be another way that you could classify composites and it is based on the depth of cure of your composite. How deep or how much thickness of composite can you cure at one time. Right now we have a lot of bulk-fill-based restorative materials on the market. These typically have a higher depth of cure and allow you to place composite in more bulk increments and cure those increments all at one time compared to traditional incremental fill. And the last way you can classify composites is really based on how you cure the composite. We don’t really use a whole lot of self-cure direct composite materials now. And probably the most popular one that you may use on a regular basis would be something similar to like a core build-up material but typically the majority of the composites that we use right now are basically light polymerized composites and that is another way that you can classify composite resins.
So out of the seven different types of composites we’re gonna talk about today there are gonna be basically three broad categories that these seven will fit in and those three broad categories are paste composites, global composites, and bulk-fill composites.
So, the first composite we’re going to talk about is micro-fill composites. These have been on the market for an extremely long amount of time and some of the features of micro fills that you may find useful are that they typically contain small irregular-shaped particles and these particles have a very high surface area. Now because they’re small irregular and they have a high surface area it’s really hard to pack a lot of these particles into the composite so that means that micro field composites typically have a lower filler content. Lower filler content remembers means that
the physical and mechanical properties of this composite are not as good so they’re not very strong composites. However, Micro Field composites can be polished and they do have some of the best aesthetics of some of the composites on the market and that’s a nice thing if you’re looking for good aesthetics. However, if you’re thinking about placing these in stress-burying areas like class 1 and class 2 restorations in the back of the mouth, you may want to think about a different type of composite. The last thing about micro fills is they have a modulus of elasticity that is very similar to the tooth which means that these composites are really good for things like class 5 non-carius cervical lesions where you have possible flexure of the tooth and if they flex at the same rate the tooth does they actually hold up a lot better in the long term.
The second category of composites we’re going to talk about is nano-fill composites. Now, a true nano-fill composite means that every particle in the composite is less than 100 nanometers. This is ideal because you have such small particles, you can pack a ton of these particles into the composite which means that you have a very high filler content and you have very high strength. Another nice feature is because these particles are so small you can actually polish the composite very nicely as well. So, typically nano fills have kind of the best of both worlds. They have really good strengths and really good aesthetics. A good example of a true nano field would be phil tex of premium ultra from 3m espe.
The third composite you need to know is micro hybrids. This is just one of two different types of hybrid-based composites. Hybrid means that you have a mixture of small particles and large particles. Now, with a micro heart hybrid, you actually do get really good filler loading meaning that the strength of these composites is really good, and polish ability is not bad either. Typically
though these composites will look really good on the day of placement but then over time, months and months later even years later they’ll start to lose or polish. They’ll start to look a lot rougher on the exterior. Another feature of micro-hybrid composites is that they contain some larger particles. As this composite wears over time some of those larger particles at the surface will become more exposed due to the wear and they’ll actually be plucked out of the resin itself and this can leave voids or basically almost something that looks like potholes. If you ever see a composite that looks very rough on the surface, it’s a good chance it’s a micro-hybrid.
Next, we’re going to talk nanohybrids now. When we’re comparing nano hybrids to some micro hybrids they’re extremely similar. They have basically the same strength and properties because you do have about the same amount of filler loading with these materials. Another thing to consider though is that nano hybrids do contain nano-sized particles. However, they’re not true nano fills because they do not contain only exclusively nano particles, they’re actually mixed with other larger-sized particles, and again with micro hybrids and nano hybrids you do get good strength with these you get pretty good aesthetics. So, really across the board, they’re good universally accepted composites.
The next category of composite we’re going to discuss is flowable composites. Now, these typically have a lower filler content and a higher resin matrix content because it contains lower amounts of filler. It’s not as strong as pastes-based composites and because the matrix content is higher it does tend to shrink more. Now, that can be kind of a negative side effect because if you’re placing this as the sole only restoration you could have a little bit more shrinkage. These types of composites are really good for small conservative restorations, for liners, or for situations where you’re really just kind of placing something like a sealant or preventive resin restoration. Now, the other thing is that they have a modulus elasticity that is very similar to the tooth. This means that the restoration will actually flex with the tooth that making these very good for liners and for non-caries cervical lesions such as class 5 cervical lesions.
The next composite we’re going to talk about is flowable bulk fills, also known as base bulk fills. Now, these typically are a little bit more flowable in nature. However, they have considered bulk fills which means that you can place these in basically higher or deeper increments than traditional composites because they are bulk fills and they’re flowable. They typically have a lower filler content in higher matrix content. The lower filler content is advantageous in this case because it does give you an ink of cure because the filler content is low. However, these composites are not as strong and most of them are indicated as base layers, meaning that you would fill your preparation up say like four millimeters with your flowable bulk-fill, and then you have to actually cap that bulk-fill with a two-millimeter increment of traditional paste composite.
The last type of composite you need to know is a full-body bulk fill, meaning a true bulk fill that you can actually place from the bottom of your prep to the top of your prep and theoretically one increment if it’s not too deep. Obviously now these types of composite restorations do have a high filler content and they’re very strong the nice thing is that you can place them in greater than two-millimeter increments.
So, that’s going to be it for this article on seven different types of composite that you need to know in your restorative practice. If you’d like more information on composite filling procedure or top composite restoration tips, please check our blog articles.