HOW TO “GO WITH THE FLOW”
1. Check the indications From core build-ups to pit and fissure sealants, flowable composites have been recommended for many indications – but not all. Always double check what your material is capable of before counting on it to perform in every situation. On the flip side, many dental professionals underutilize flowable composites based on the limitations of early generation products. But there’s a reason these low-viscosity materials are suggested for nearly every indication – they’ve come a long way in their performance since their inception and have improved in nearly every way, including their versatility. So before writing off a flowable composite as a viable option, verify its capabilities.
2. Choose the right viscosity Flowable composites are defined by their low viscosity, which can provide easier flow, more rapid filling, improved syringe delivery and better cavity adaptation. You can count on flowable composites to be less viscous than your traditional, paste-like composite – but they don’t all flow, or perform, the same way. Flowables are available in a wide variety of viscosities that can be useful in many different clinical situations, and it’s not enough to simply select the most fluid option. Lower viscosity can translate to more shrinkage stress, reduced mechanical and physical properties, and run-on or slumping. With this in mind, make sure you’re using the correct viscosity for each situation or case. For example, some compositions feature thixotropic properties that allow the material to flow well during extrusion and thicken within the cavity prep, others “self-level”, while yet others have utilized novel monomer mixtures to lower viscosity without increasing polymerization shrinkage.
1 Check out our article to learn more about monomers: 3. Know what fills your flowable First-generation flowables owed their low viscosity to lower filler content. However, reducing filler content can have a huge impact on physical, mechanical, and especially wear properties. This trade-off is why many clinicians still distrust flowables or are hesitant to use them in load-bearing areas. But as mentioned earlier, flowable composites have evolved dramatically in many ways – including filler composition. Newer materials use different filler particle sizes, shapes and concentrations to improve mechanical properties while maintaining that desirable low viscosity and related flow characteristics. For example, some current generation flowables feature nano-sized filler particles that provide excellent wear resistance, strength, polish retention, and optical properties – all while reducing polymerization shrinkage. Keep fillers in mind when selecting your restorative: in addition to viscosity, they affect adaptation, shrinkage stress, other rheological effects, and durability.
To learn more about filler, check out our article: 4. Keep an eye on esthetics In addition to being strong and wear-resistant, the ideal flowable composite should provide esthetic, natural-looking results. But there are a number of factors that go into matching natural dentition, including color, translucency, fluorescence, radiopacity and polish retention – and not every flowable brings the same level of esthetics to the table. While flowables are available in a wide variety of shades designed to reproduce target tooth color, they can often be more translucent, less radiopaque and less fluorescent than their universal composite counterparts, due to their decreased filler content. This limits their usefulness in certain clinical situations.
2 However, the inclusion of nanotechnology has allowed certain manufacturers to address optical properties at the nanoscale – and provide versatile flowable composites with high fluorescence, radiopacity, polish and improved wear rivaling that of some universal composite materials.
5. Use to line the base of restorations Because flowable composites have demonstrated improved cavity adaptation, they’re often used as a liner under composite restorations to seal the margin – which can prevent sensitivity and secondary caries. In fact, studies have shown that using a flowable as a liner can result in less microleakage regardless of whether a conventional or nanofilled composite is used.
3 NOTE: Resin Modified Glass Ionomers (RMGIs) are a solid alternative to flowable composites – both can be used successfully to line a restoration.
6. Use for difficult or complex preps and minimally invasive treatment As the demand for minimally invasive treatment increases, clinicians are seeking new methods to treat conditions while preserving healthy oral tissue. Flowable composites lend themselves to this philosophy, as their low viscosity allows the material to flow into all the nooks and crannies of small, complex cavity preps without unnecessarily sacrificing healthy tissue. By making use of flowables, you can open a door to a new avenue of treatment.
7. Make sure your delivery method delivers One of the biggest complaints that clinicians have about flowable composites are the bubbles that appear during dispensing. These tiny voids can cause staining, optical defects, microleakage and limit the lifetime of the restoration – but they can be hard to see and even more difficult to get rid of once they’re in the prep. There are many different recommended methods to reduce bubbles, including re-etching, vertical storage, or incremental placement and filling of voids with additional composite. But each requires additional, time-consuming steps. A better solution may lie in a different delivery method. Some syringe systems are designed to eliminate bubbles and material run-on, while improving overall handling characteristics. Making sure your material and delivery method work together will bring you closer to a bubble-free restoration.
8. Explore new ways to use your flowable. As stated earlier, flowable composites are recommended for many different indications – including some you may not expect. Take the time to investigate new ways to use flowable restoratives, how to take advantage of their strengths, and how they can open doors to improved patient outcomes. Some options to consider: • Bonding orthodontic brackets and retainers • Abfraction lesions and erosive lesions • Repair of small defects