In 2009, the launch of SDR^® (Smart Dentin Replacement) bulk-fill composite revolutionized restorative dentistry. It was the first technology to enable 4 mm bulk placement in a flowable consistency. More than 135 million applications[1] and several long-term clinical studies later, SDR^® flow+ is the bulk-fill technology of choice for quick and easy direct restorations with clinically reliable results.[2]

Charlotte, N.C., April 23, 2025.  Bulk-fill composites were developed in the late 1990s. They consisted of a higher proportion of filler and showed less volume shrinkage than universal composites, whose polymerization stress often caused marginal gaps and led to clinical failures when placed in larger increments. The first bulk-fill composites had to be packed into the cavity to ensure the necessary adaptation. Since 2009, flowable bulk-fill composites have been available whose polymerization stress was comprehensively analyzed.[1] Tests showed that the special flowable bulk-fill chemistry in SDR^® flow+[2] from Dentsply Sirona had the lowest shrinkage stress. This unique property makes SDR^® flow+ a trusted standard bulk fill material for posterior cavities to this day. It is one of the most commonly used self-leveling bulk fill composites for underfillings in Class I and II restorations.  

Seamless adaptation for more efficiency in dental procedures

The flowable composite enables gap-free restorations even in hard-to-reach areas and is indicated for a variety of dental procedures, including filling Class I, II, III and V cavities, sealing pits and fissures, and even for core build-ups prior to crown placement. Because SDR^® flow+ filling material can be applied in one step to a depth of up to 4 mm, a restoration can be completed in less time and in fewer steps. In addition, the adaptable, self-leveling bulk fill composite flows—even against gravity—into all recesses of the cavity, helping achieve seamless adaptation. Manipulation using an instrument is not necessary. Excellent clinical results can be reliably achieved by reducing the risk of marginal gaps and secondary caries. Another advantage of SDR^® flow+ is its high radiopacity, which simplifies long-term monitoring of the restoration. Dr. Alan Atlas, a dentist specializing in restorative dentistry from Philadelphia, USA, has been using Dentsply Sirona's bulk fill composite for many years: “After 15 years, SDR Flow+ remains the most effective composite ever developed for dentin replacement in direct restorations. Its ability to seal dentin margins is especially crucial in Class II posterior composites, significantly reducing the risk of recurrent decay and postoperative sensitivity. It has truly been a game changer in restorative dentistry.”

Both dentist and patient benefit

SDR^® flow+ can also increase the productivity of the dental practice. Direct restorations account for about one third of the annual turnover of a general dental practice. Ugurlu et. al. concluded in a retrospective study[3] that SDR^® flow+ can reduce the time required for posterior fillings compared to conventional composites and extended layering techniques. This, in turn, has the potential to improve the cost-effectiveness of the practice. SDR^® flowable bulk-fill technology also eliminates the need for an additional liner prior to application, which reduces the practice inventory.

Patients also gain from shorter treatment times, especially children and those who have difficulty tolerating prolonged dental treatment. SDR^® flow+ also has a low risk of post-operative sensitivity.² In addition, the clinical longevity of the restoration is not compromised and is as effective as using small increments in a conventional technique.³ Besides the universal shade, SDR^® flow+ is available in three additional shades (A1, A2, and A3), making it very easy to achieve esthetic results in various indication areas and for restoring visible proximal walls of class II cavities.

“With the development of SDR^® and SDR^® flow+, Dentsply Sirona has come up with a real game changer in restorative therapy,” explained Julie Mroziak, Vice President Restorative Solutions at Dentsply Sirona. “Today, it is one of the most extensively studied dental restoration materials and has achieved very good clinical results in over 135 million restorations. In vitro and clinical studies prove that dentists can advance with confidence by using SDR^® flow+ as a bulk-fill flowable—a high-quality material because of its adaption and efficiency for direct restorations.”

Learn more about SDR^® flow+ here: SDR® flow+ | Bulk Fill Flowable | Dentsply Sirona Global

[1] Kaisarly D, Langenegger R, Litzenburger F, Heck K, El Gezawi M, Rösch P, Kunzelmann KH. Effects of application method on shrinkage vectors and volumetric shrinkage of bulk-fill composites in class-II restorations. Dent Mater. 2022 Jan;38(1):79-93.

[2] Marketed as SDR® flow+ Bulk Fill 
Flowable or SDR® Plus Bulk Fill Flowable based on location. 

[3] Ugurlu M, Sari F. A 3-year retrospective study of clinical durability of bulk-filled resin composite restorations. Restor Dent En-dod. 2021 Dec 30;47(1):e5.