Ongoing Modifications to Filler Particles Are Moving Us Closer to True Universality
Marcos Vargas, BDS, DDS, MS
Because resin composite restorations are one of the most commonly performed dental procedures, fully understanding the key features of this material can be a critical factor that impacts a practice's efficiency and treatment outcomes.
When resin composite was first introduced to dentistry, it offered several distinct benefits, the most notable being "tooth-colored" esthetics. As the material gained traction in dental practice, adhesives were developed that facilitated more conservative preparations.
Composites have progressed from macrofills to microfills; then to hybrids and microhybrids; and then to nanocomposites and nanohybrids. Throughout these modifications, the size and distribution of the filler particles was the aspect that changed the most, moving from larger particles to much smaller particles and clusters. Incorporating a higher number of particles resulted in composites with better physical properties. At the same time, manufacturers were developing particles that would facilitate more esthetic restorations with better polishability that sustain their luster long-term.
Bulk-fill composite materials are the most recent, highly practical innovation, allowing clinicians to place material in larger increments. Bulk-fill composite is invaluable for posterior restorations because, along with faster, easier placement, it offers reasonably good esthetics. In addition, bulk-fill composite demonstrates more translucency, allowing it to be cured to a deeper level.
Regarding the strength and wear attributes, research demonstrates that, although some microfills are deemed weaker, most modern composite materials are comparable. In retrospect, the technology of resin composites hasn't advanced significantly in recent years. Instead, the established materials have been subtly refined, fine-tuning the details to meet the demands of different restorative scenarios.
Until composite technology has advanced to the point that a truly "universal" product is developed (ie, one that can not only be used universally, but universally without compromise), dentists will continue to work around the limitations or rely on multiple products to achieve the necessary strength and esthetics for various clinical situations.
Marcos Vargas, BDS, DDS, MS, is a professor in the Department of Family Dentistry at the University of Iowa's College of Dentistry. His primary interests are in the area of dental materials, including glass ionomers, dentin bonding, composite resins, and esthetic dentistry. An active member of the American Academy of Cosmetic Dentistry, the Academy of Operative Dentistry, the American Dental Association, and the International Association for Dental Research, he lectures nationally and internationally on cosmetic dentistry.