Hold Firm, Or Go With the Flow? by Dr. Foroud Hakim

A rubric for deciding composite viscosity selection

by Dr. Foroud Hakim

Composite resin has become the most common material selected by practitioners for direct restorations over the past three decades. An expanding desire for tooth-colored restorations, advancements in material science and simplification of delivery are equally responsible for doctors choosing composites for an expanding list of clinical indications.

Insurance company reimbursement data indicates that Class I and II restorations account for nearly 70% of composites delivered in contemporary practices. A combination of Class III, IV and V restorations account for most of the remaining procedures submitted. Through research and development, manufacturers continue to provide doctors better materials and technologies. In my estimation, the four most important advancements in this area include:

Nanofiller technology. Nanofillers are in large part responsible for mitigating many of the shrinkage-related liabilities related to traditional composites by lowering values below the 2% threshold. Aesthetics, strength, handling and many other improved characteristics are attributed to nanoparticle integration.

Bulk-fill options. Volumetric shrinkage stress, depth of cure and conversion, and improvements in aesthetic potential are just a few challenges that have been overcome with modern bulk-fill entries. They allow practitioners to reduce delivery time, simplify technique, and reduce voids and gap formation associated with traditional layering.

Predictable adhesion. The evolution of bonding agents affords practitioners simplification with respect to delivery, expanded and improved adhesion to various substrates (including predictable dentin bonds), and just plain stronger bonds with reduced deviations.

Viscosity variations. One of the most important advancements in composite differentiation is the expanded menu revolving around viscosity. Not only do the traditional body composites present in a variety of viscosities ranging from very creamy to mid-consistency and all the way to firm, but all of these also can be further modified via the introduction of heat using composite warming technologies that continue to gain traction. Added to this is an increased menu of flowable composites that can range from highly flowable to the heaviest of viscosities.


The balance of the article will focus on composite viscosity—in particular, critical and intentional viscosity variation based on the clinical circumstance. In my opinion, and through my observations when providing continuing education to colleagues, viscosity selection is an underutilized strategy that can greatly benefit doctors in daily practice while helping to improve outcomes and efficiency.


Case 1

A 64-year-old patient presented with recurrent decay involving a long-standing occlusal amalgam on tooth #30 (Fig. 1). After anesthesia, the old restoration and all remaining infected tooth structure was removed (Fig. 2) under Isolite isolation (Zyris). A selective-etch approach to tooth conditioning was employed, with the enamel margins etched with 37% phosphoric acid (Fig. 3) using Ultraetch (Ultradent) for 20 seconds. After application of the eighth-generation adhesive Futurabond U (Voco) and appropriate light curing, a thin layer of an opaque shade of flowable composite (Grandioso Flow Opaque A2, Voco) was deployed to mask the amalgam-stained dentin and mitigate any unsightly shine through (Fig. 4).

Final restoration (Fig. 5) was achieved using X-tra Base bulk-fill flowable composite (Voco) in a universal shade for the base layer and Grandioso nanohybrid composite (Voco) in shade A1 for the capping layer.

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