Flowable composite resins made their debut in the dental world in 1996, but they didn’t make a very big splash. Originally developed to simplify the placement technique and expand the range of clinical applications for resin composites, these first-generation flowables failed to impress as clinicians quickly found that they demonstrated poor clinical performance and did not achieve predictable, long-term results because of inferior flexural strength and wear resistance compared with conventional hybrid composites. However, over the past 20 years flowable composite resins have been re-evaluated and redesigned with extensive improvements to their chemistry in order to increase their usability in dentistry.
The most dramatic and clinically effective improvement between the first- and next-generation flowable composite resins is the filler component. Next-generation flowables make use of filler components with finer particle size, shape, orientation, and concentration. The result is a resin composite with dramatically improved mechanical properties, making the materials comparable to conventional hybrid composites. The improved filler component also improves the esthetic and optical qualities of the flowable by using a polychromatic double-layer effect similar to the color relationship between natural enamel and the underlying dentin. These flowable resins can be layered over each other for subtle color combinations that give esthetic dentists unparalleled freedom in developing natural-looking, esthetic restorations.
But next-generation flowables didn’t just improve upon their own recipe; according to recent studies, certain flowable composites (G-aenial Universal Flo, G-aenial Flo, and Clearfil Majesty Flow) have shown significantly greater flexural strength and a higher elastic modulus than the manufacturers’ corresponding conventional composite materials. Combine these benefits with the easier and more convenient application technique—flowable composite resins were always intended to improve upon the scoop-and-pack technique of conventional hybrid composites—and you have a composite material that can create predictable, customizable, durable restorations chairside.
Understandably, some clinicians who gave the first-generation flowables a chance may be reluctant to offer the benefit of the doubt to this new generation. However, current research and the clinical experience of those who have tried the next-generation materials proves that the technology today is not the technology of 20 years ago. As Dr John M. Powers has stated, the flowable today is not really a flowable—it’s an injectable composite. The next-generation flowables are proving themselves to be viable fulfillments to those promises manufacturers made in the past. They can be used for anterior and posterior composite restorations; sealants and preventive resin restorations; fabrication, modification, and repair of composite prototypes and provisional restorations; intraoral repair of fractured ceramic and composite restorations; elimination of cervical sensitivity; resurfacing of occlusal wear on posterior composite restorations; development of composite prototypes for copy milling; and the placement of pediatric composite crowns. There is seemingly no end to the ways a creative dentist can use these new flowables.
One dentist who is already making use of the new formulations is Dr Douglas A. Terry of Houston, Texas. In his new book, Restoring with Flowables, he describes the many clinical uses of flowables and the science behind their success, and he also presents guidelines and case reports for specific applications. To him, the decision to use flowables in clinical situations where others may choose ceramic veneers or crowns is all about the patient. Flowables are a much more affordable option for many patients than ceramics, and they also drastically reduce the treatment time. “I’m like most people,” he says, “and if some doctor tells me it’s going to be $10,000 to get my mouth done, I’m going to think, ‘Well, can we make this in payments for the next 10 years?’ I think these techniques are great because everyone can get it, and esthetics is something that needs to be given. A lot of people can’t have 10 crowns done next week, but does that mean they don’t deserve anything?”
It is not a bad thing for clinicians to defer to the options they personally know will achieve successful results for their patients. However, Dr Markus B. Blatz has said that “the incredible breadth of clinical applications of modern flowable composites, especially in combination with a novel injection technique . . . calls into question the validity of many ‘traditional’ treatment concepts and materials.” So what will it take for more clinicians to give the new generation of flowables a chance?
In some cases, the reluctance to try flowables before ceramics could be a costly mistake. Dr Terry describes a patient who came to him last year with two peg laterals who had seen seven different cosmetic dentists to solve the problem: “First, they did a composite veneer, and it fell off. Then they did a composite ceramic veneer, but it didn’t work. Then they prepared it for a crown, but they exposed a nerve and had to do a root canal. Then she lost her papilla from that procedure and had to have periodontal surgery. After that, she saw another doctor because there was space between the teeth, so they added to the other tooth and they messed up that tooth. So she came to me after seven doctors, and she had spent a fortune. If she had come to me first, I could have had it done in 45 minutes and she would have been out the door, done.”
“I’m not saying that this is a cure-all for all your needs,” Dr Terry continued. “I’m trying to give parameters and ideas of how to use these concepts so you can do more and utilize your imagination. Whether it’s for a prototype or a final restoration, you have to utilize good clinical judgment and experience. You can utilize these materials and you can still go to ceramics afterward if you want. But what do you have to lose?”
As with any new biomaterial, research must be done to fully measure and evaluate the capabilities of flowable composite resins. However, recent studies and clinical experience so far indicate there is a bright future ahead for flowables as they etch their place in modern esthetic dentistry. For more information on the clinical applications of flowable composite resins, please refer to Dr Terry’s forthcoming book, Restoring with Flowables.