Laird Harrison

March 29, 2012

March 29, 2012 (Tampa, Florida) — A clinical trial pitting two 2-bottle adhesives against a 1-bottle adhesive showed them almost equally effective after 3 years, researchers reported at the American Association for Dental Research (AADR) 2012 Annual Meeting here.

The head-to-head trial compared 3 products by 3M Espe against each other in noncarious cervical lesions and found a statistical disadvantage for the 1-bottle product only in measurements of margin integrity.

"It's just the margins and it's probably because that's where you have the most tension," first author Augusto Robles, DDS, MS, an assistant professor of dentistry at the University of Alabama in Birmingham told Medscape Medical News.

Dental adhesive companies have worked for years to reduce the number of steps needed to apply adhesives to restorations by combining etches, primers, and adhesives in 1 bottle. But most research has shown that combining these ingredients results in a weaker bond.

Although many trials every year compare dental adhesives with each other, most are done in laboratories and only approximate the conditions under which restorations are meant to stick to teeth.

In this study, researchers tried 3 different adhesives, all made by 3M Espe (which provided a grant for the study). They used the adhesives to place 3M Espe Filtek Supreme Plus composite resin restorations.

Adper Single Bond Plus requires 6 steps. Practitioners must etch the tooth surface, rinse, blot, apply adhesive, air, and finally cure.

Adper Scotchbond SE also requires 6 steps, but instead of incorporating the primer and adhesive, it incorporates the etchant and adhesive. Practitioners must prime the tooth surface, apply the adhesive, agitate, apply adhesive again, and cure.

By contrast, Adper Easy Bond contains etchant, primer, and adhesive in 1 bottle. It requires only 3 steps. Practitioners apply the adhesive, then dry and cure.

The researchers placed the restorations in 126 class V noncarious cervical lesions in 50 patients. They chose cervical lesions because the patients' bite and food choices, which can vary from one patient to another, are less important factors for the durability of this type of restoration, Dr. Robles said.

The researchers evaluated the patients at baseline (2 weeks after placement of the restoration) and again at 6, 12, 24, and 36 months. They measured retention, anatomic form, color match, margin integrity, margin discoloration, surface roughness, secondary caries, staining, gingival index, and postoperative cold sensitivity using modified US Public Health Service criteria.

After 3 years, 6 restorations failed. The retention rates were 94% for Single Bond Plus, 97% for Scotchbond SE, and 92% for Easy Bond. These differences were not statistically significant (P > 0.05).

The only criterion for which a difference emerged was margin integrity: 72% for Single Bond Plus, 84% for Scotchbond SE, and 49% for Easy Bond. These differences were statistically significant, Dr. Robles said (the P value was not available at press time).

The restorations were divided among anterior, molar, and premolar teeth; a roughly equal proportion of each was restored with each of the adhesives. In a new study now underway, the researchers are more systematically accounting for tooth type and bite intensity, Dr. Robles said.

Asked to comment, Afnan Omar Alzain, DDS, MS, told Medscape Medical News that the study was well designed on the whole. "The results seem pretty good," she said. The difference in marginal integrity can be misleading because a coffee or tea stain can affect these results, she pointed out.

3M Espe provided funding for this study. Dr. Robles and Dr. Alzain have disclosed no relevant financial relationships.

American Association for Dental Research (AADR) 2012 Annual Meeting; Abstract #408. Presented March 23, 2012.


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