Immediate repair bond strengths of microhybrid, nanohybrid and nanofilled composites after different surface treatments.
OBJECTIVE
To evaluate immediate repair bond strengths and failure types of resin composites with and without surface conditioning and characterize the interacting composite surfaces by their surface composition and roughness.


METHODS
Microhybrid, nanohybrid and nanofilled resin composites were photo-polymerized and assigned to four groups: (1) no conditioning (Control), (2) no conditioning, polymerized against a Mylar strip (Control, with strip), (3) intermediate adhesive resin (IAR) application, and (4) chair-side silica coating, silanization and intermediate resin application (SC). Resin composites, similar as their substrates, were adhered onto the substrates. Shear force was applied to the interface in a universal testing machine and failure types were evaluated under light microscopy. Surface characterization was done by contact angle measurements, X-ray photoelectron spectroscopy, scanning electron and atomic force microscopy.


RESULTS
Significant effects of the resin composite type and surface conditioning were observed. Conditioning the composites with their IARs does not result in significant improvements in bond strength compared to the control with strip (bond strengths between 14.5 and 20.0 MPa). SC increased the bond strength in all composites except TE by an average 8.9 MPa, while in all composites the surface roughness increased from 7 to 384 microm. Failure types in this group were exclusively cohesive. Physico-chemical modelling of the composite surfaces showed that the surfaces were dominated by the resin matrix, with a major increase in silica-coverage after SC for all composites.


CONCLUSIONS
Intermediate adhesive resin conditioning did not improve the composite-to-composite immediate repair strength. Silica coating and silanization followed by its corresponding IAR, strongly increased repair bond strengths and provided exclusively cohesive failures in the substrate in all composites.
Rinastiti
Margareta
M
Department of BioMedical Engineering, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands.
Ozcan
Mutlu
M
Siswomihardjo
Widowati
W
Busscher
Henk J
HJ
D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D055598:Chemical Phenomena; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding / Q000379:methods*; D003764:Dental Materials / Q000737:chemistry*; D017269:Dental Prosthesis Repair; D003799:Dental Stress Analysis / Q000295:instrumentation; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D011108:Polymers / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D017155:Wettability
D003188:Composite Resins; D003764:Dental Materials; C515951:Filtek Supreme Plus; C509998:Grandio; D008689:Methacrylates; D011108:Polymers; D019279:Resin Cements; D012821:Silanes; C488002:Solobond Plus adhesive; C501891:Tetric EvoCeram; C502351:multilink adhesive system; C523291:quadrant anterior shine; C017492:methacryloxypropyltrimethoxysilane; D017438:Bisphenol A-Glycidyl Methacrylate; D012822:Silicon Dioxide; C081713:Visio-Bond; C041330:Scotchbond