Immediate repair bond strengths of microhybrid, nanohybrid and nanofilled composites after different surface treatments

Rinastiti, Margareta; Özcan, Mutlu; Siswomihardjo, Widowati; Busscher, Henk J.

doi:10.1016/j.jdent.2009.08.009

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Volume 38, Issue 1 , Pages 29-38, January 2010

Immediate repair bond strengths of microhybrid, nanohybrid and nanofilled composites after different surface treatments

Margareta Rinastiti
- Department of BioMedical Engineering, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Department of Conservative Dentistry, Faculty of Dentistry, Gadjah Mada University, Yogyakarta, Indonesia
Mutlu Özcan
- Department of Dentistry and Dental Hygiene, Clinical Dental Biomaterials, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
Widowati Siswomihardjo
- Department of Biomaterials, Faculty of Dentistry, Gadjah Mada University, Yogyakarta, Indonesia
Henk J. Busscher
- Department of BioMedical Engineering, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Corresponding author at: Department of Biomedical Engineering, University Medical Center Groningen, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands. Tel.: +31 50 363 3140; fax: +31 50 363 3159.

Received 25 May 2009; received in revised form 27 August 2009; accepted 27 August 2009. published online 07 September 2009.

Abstract

Objectives

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 20.0MPa). SC increased the bond strength in all composites except TE by an average 8.9MPa, while in all composites the surface roughness increased from 7 to 384μm. 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.

Conclusion

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.

Keywords: Immediate layering, Intermediate adhesive resin, Microhybrid composite, Nanofilled composite, Nanohybrid composite, Repair, Resin composite, Silica coating, Surface conditioning