Microtensile Bond Strength, Bonding Interface Morphology, Adhesive Resin Infiltration, and Marginal Adaptation of Bulk-fill Composites Placed ﻿Using Different Adhesives.
PURPOSE
This study evaluated dentin bond strength, failure mode, interface morphology, adhesive infiltration into dentin, and marginal adaptation of bulk-fill composites used with different adhesives.


MATERIALS AND METHODS
Third molars received occlusal class I cavities (4 mm x 4 mm x 4 mm) that were bulk-filled with Admira Fusion x-tra (Voco) or SonicFill 2 (Kerr) using four adhesives (Scotchbond Multipurpose, 3M Oral Care; Clearfil SE Bond, Kuraray Noritake; OptiBond All-In-One, Kerr; Futurabond U, Voco). Scotchbond was used with acid-etching, while the remaining adhesives were applied in self-etch mode. Sixty-four teeth were selected for the microtensile bond strength test (n = 8). Failure modes were analyzed with scanning electron microscopy (SEM). Interface morphology and adhesive infiltration (n = 3) were investigated using confocal laser scanning microscopy (CLSM). Marginal adaptation (n = 3) was also evaluated using SEM. Bond strength, failure mode, and adhesive infiltration data were analyzed for distribution and homocedasticity, followed by appropriate statistical analyses (α = 0.05).


RESULTS
Regarding bond strength, no differences were found among adhesives for SonicFill; Clearfil showed a significantly lower mean value than did Scotchbond (p ≤ 0.05) for Admira; the two composites did not differ. Adhesive and mixed failures were observed for all groups. Scotchbond led to thicker hybrid layers with deeper adhesive infiltration as opposed to Futurabond. The groups Admira+Futurabond, SonicFill+Clearfil, and SonicFill+Futurabond presented the highest marginal discontinuity.


CONCLUSION
The tested bulk-fill composites did not affect dentin bonding. Scotchbond and Clearfil seem to be reliable for bonding SonicFill 2 to dentin. ﻿The performance of Futurabond ﻿was questionable﻿, given its poor-quality interface and higher percentages of marginal gaps.
['Sebold|Maicon|M|', 'Lins|Rodrigo Barros Esteves|RBE|', 'Sahadi|Beatriz Ometto|BO|', 'Santi|Marina Rodrigues|MR|', 'Martins|Luís Roberto Marcondes|LRM|', 'Giannini|Marcelo|M|']
D000269:Adhesives D003188:Composite Resins D001840:Dental Bonding D003738:Dental Cements D003804:Dentin D017220:Dentin-Bonding Agents D008422:Materials Testing D008855:Microscopy, Electron, Scanning D019279:Resin Cements D013718:Tensile Strength
adhesive dentin composite resin dental bonding dental etching ultrasonics