March 2011, Volume 32, Issue 2
Published by AEGIS Communications
Kerr Develops Adhesives with Improved Performance
At Kerr, they believe the best results come from covering the most fundamental step in the restoration—providing excellent adhesion. Michael Padilla, senior product manager, explains, "We think it’s really important to let the clinicians know that the adhesive step is the most critical part of their restoration. So we’ll continually strive to develop adhesives that provide improved clinical performance and ease of use and increased utility."
As an example, Padilla points to the long-term use and clinical success of total-etch bonding. "When the total-etch technique is performed right, clinicians can achieve really great outcomes. At Kerr, when we develop new dental adhesives, we compare them to our total-etch products, because we know that any new adhesive needs to maintain that standard."
Kerr now offers an adhesive for every generation to meet the specific needs of almost any restorative case. "Dentists don’t use just one adhesive," Padilla says. "They’ll use two or three different adhesives depending on the nature of the case. For example, the great thing about self-etch adhesives is they provide a secondary option in cases where a total-etch adhesive may not be appropriate. Self-etch adhesives have provided effective, reproducible techniques, while making procedures more efficient."
Marcos Vargas, DDS, MS, Professor, Department of Family Dentistry, University of Iowa, agrees that selecting the right product from all the available categories of adhesives is key. "For example, there’s still a significant difference between the three-step and two-step total-etch, even though two-step seems to be more popular," he says. "We have shown over and over in clinical studies that total-etch three-step adhesives are the best so far."
However, he explains that it’s important to differentiate between adhesion to enamel and adhesion to dentin. "We’ve been doing adhesion to enamel for more than 50 years—it’s very reliable, very secure, and fills very well. I believe the best way to bond to enamel is to etch the enamel. But adhesion to dentin is more difficult, because of the nature of the dentin, and I think the trend might be changing to self-etch. Based on very good literature reviews and clinical studies, self-etch two-step products are probably the ones that are going to become the standard for dentin." Whatever product is selected, Vargas recommends that it should be an adhesive with a good reputation, backed by clinical studies.
"If you traced our adhesive portfolio over the last 20 years, Kerr has been a leader in the dental adhesive area," Padilla says. "The technology within the OptiBond™ brands provides vehicles for exceptional adhesion and bond strength, effective dentin penetration, and sealing, as well as ruggedness, to provide good bond durability."
The company recently launched Opti Bond® XTR, a sixth-generation product. "We saw opportunities and weaknesses in current sixth-generation bonding agents," he says."Studies—internal and external—have shown XTR is comparable in bond strengths to a total-etch on enamel. Moreover, XTR can be used for direct and indirect applications. A lot of light-curing bonding agents can’t be used for indirect restorations due to film thickness or incompatible chemistries, but XTR solves that problem. Clinicians are very excited about it— some have said an adhesive such as XTR could help reduce their adhesive inventories and simplify their office techniques."
"When we first launched XTR, some clinicians asked why we were going backwards, to a sixth-generation," Padilla continues. "We didn’t go back and think, hey, we’re missing a bonding agent in the sixth-generation area. Instead, we did our homework and realized that doctors need this product with these features—and that’s what XTR is all about. We’ve looked at issues found in every generation and improved upon them with XTR."
Padilla cautions that it’s important for clinicians to keep in mind that the generational nomenclature reflects only the adhesive technique procedure and the number of components in the adhesive system. "It doesn’t speak to indication or performance," he says. "I think it's possible to develop an eighth-generation adhesive, but more realistically, at Kerr we strive to develop dental adhesives with improved performance and ease of use. That could include an improved fourth-generation or fifth-generation." Vargas anticipates that future advances will be in the area of self-etch adhesive materials. "They don’t need to have an adhesive to bond to the structure," he says. "There are already materials in the market (such as Vertise™ Flow from Kerr) that are attempting to do this—to completely do away with adhesive, and just have the material be adhesive by itself. So I think that will be on the horizon—self-adhesive restorative material."
"I can happily say that there’s still a lot of room for improvement in adhesives, and we’ll continue to focus our efforts there," Padilla adds. "Because if you have a compromised adhesive layer, you’ll have failures—restorations falling out, increased microleakage, secondary caries. Especially in today’s market, patients want the best results, and at Kerr we know the best results come from providing exceptional adhesion."
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