Introduction

Dental Composites, also known as composite restorative materials, filled resins, composite resins, resin-based composites or filled composites. Composite restorative materials are the most commonly used restoration since they replace biological tissue in appearance and function. At least 40-52% of posterior direct restoration placements now rely on composite materials broadly categorized according to the filler particle size, restorative procedure, clinical application, and curing methods.

Different Types of Dental Composites

Let's discuss all the types of composite based on filler particle size.

Micro-Fill Composite

First are the small micro-fill composites of irregular-shaped particles with high surface area. These have lower filler content, implying that the microfill composite strength is reduced compared to the other options, although microfill composites can be polished and give aesthetic results.

Nano-Fill Composite

Measuring 100 nm in size, these nano-fill composites are small particles with high filler content and provide great strength to the material. It is a material of choice for an ideal case as it has outstanding strengths and excellent aesthetics.

Micro-Hybrid composite

Moving on to the micro hybrids composite, this is just one of the two different types of hybrid-based composites. The word hybrid indicates the combination of both a small and a large particle.

It has good filler loading, due to which strength is not compromised and provides good aesthetic quality.

With time, studies have reported a loss of polish or luster with micro-hybrid composites.

Nano-Hybrid Composite

Next is the nanohybride composite. When we're comparing nano-hybrids to some micro-hybrids, they're extremely similar. They have the same strength and properties because it has the same amount of filler loading. 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 nanoparticles; they're mixed with other larger-sized particles, and again, with micro hybrids and nanohybrids, you do get good strength along with good aesthetics, making it one of the universal accepted composites.

Flowable Composite

Moving on to the higher resin matrix and a lower filler composite, the flowable composite. This type has a probability of shrinking more; however, there are the treatments of choice. Its modulus of elasticity is very similar to that of the tooth. This means that the restoration will flex with the tooth, making these very good for liners and non-caries cervical lesions such as class 5 cervical lesions.

Flowable Bulk-Fill

The next composite is the flowable bulk fills, also known as base bulk fills. Now, these typically are a little bit more flowable, so they can be placed in higher or deeper increments than traditional composites because they are bulk fills. They typically have a lower filler content in higher matrix content. The lower filler content is advantageous in this case because it does give an ink of cure. After all, 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, four millimeters with your flowable bulk-fill, and then you have to cap that bulk-fill with a two-millimeter increment of traditional paste composite.

Full-Body Bulk Fill

The last type of composite is a full-body bulk fill, meaning a true bulk fill that can be placed from the bottom of the cavity to the occlusal surface. Now, these types of composite restorations do have high filler content, and something that is be noted is that you can place them in increments greater than two millimeters.

Factors for long-term success of composite restorations

There could be numerous factors affecting the longevity of composite restoration. These may range anywhere from patient induced such as caries risk, parafunctional habits etc. Dentist induced factors include multiple operators on a single patient, increment thickness, light unit system used, cavity diameter, filler type etc.

Here are some crucial factors:                                                                            

1. Etching and bonding: Proper concentration of acid and etching time are mandatory to achieve requisite tags. Also, make sure the acid is washed off properly, or else a lack of residual acids can hinder the bonding process.

2. Damage to the bonding interface: The resin matrix binds the fiber reinforcement, transfers loads between fibers, gives the composite component its net shape, and determines its surface quality. The failure of the restoration–tooth structure bond, or the resin–tooth interface, is the weak link whose failure is the main reason for the failure of the restoration.

3. Adhesive-composite application techniques: The longevity of bonded composite restorations could be affected by the adhesive-composite application techniques utilized. This involves adhesive preparation followed by etching and the use of dental desensitizers, which reduce the sensitivity resulting from composite restorations. When applied in the cavity before dental adhesives, they do not affect the bonding of the restorative material.

Conclusion

To summarize the key features,

Take home notes:

• The size of the filler particles in a composite can affect the strength, wear resistance, and shrinkage of the restoration. 
• Composite fillings are versatile and suitable for both anterior and posterior teeth. Their adaptability ensures that they withstand the daily pressures of eating and chewing.
• To minimize the chances of failure, one should focus on small cavity preparations, proper isolation, the use of small increments while filling the cavity, proper etching, etc.

Frequently Asked Questions

What are the advantages of using resin-based dental composites in restorative dentistry?

The resin-based dental composite does not require much drilling, so natural tooth structure is conserved. Also, they harden in seconds and bond to the tooth, giving it higher strength. 

How do dental composites differ from other restorative materials like amalgam or ceramics?

Firstly, as compared to amalgam restorations, dental composites offer great aesthetics, making them natural tooth-looking; apart from that, amalgam mercury release and bonding to the tooth structure makes composite a preferable choice. Composite resins are less brittle than ceramics.

What factors should a dentist consider when selecting the right type of dental composite for a patient?

The following factors should be considered such as polish of the material, natural tooth color, age, gender, smile makeover goals and expectations, the strength of the composite, how it wears in the patient's mouth, as well as its bond strength and adhesion. 

What are the three main components of dental composite?

The three principal components are a polymer matrix, a coupling agent, and a filler particle. The matrix is combined with filler to form a composite-like material consisting of ceramic and polymer.

How do I select the right shade of dental composite for my patients' restorations?

While selecting the right shade of the dental composite, the following points should be taken into consideration:-

1. Follow the Composite button technique.
2. Evaluating the shade in different light sources.
3. The tooth should be moist with saliva, as dehydration results in a whiter appearance. The tooth becomes dryer after the application of the rubber dam, and therefore, color matching should be performed before applying it.
4. Distance of the Operator from the tooth and Position of the patient (A distance of 61 cm (2 feet) to 183 cm (6 feet) distance from the oral cavity is considered ideal for shade matching)
5. Performing the Squint Test for Restricting Light.