University of Oulu

Stape, T. H. S., Mutluay, M. M., Tjäderhane, L., Uurasjärvi, E., Koistinen, A., & Tezvergil-Mutluay, A. (2021). The pursuit of resin-dentin bond durability: Simultaneous enhancement of collagen structure and polymer network formation in hybrid layers. Dental Materials, 37(7), 1083–1095.

The pursuit of resin-dentin bond durability : simultaneous enhancement of collagen structure and polymer network formation in hybrid layers

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Author: Stape, Thiago Henrique Scarabello1,2; Mutluay, Mustafa Murat1,3; Tjäderhane, Leo4,5;
Organizations: 1Department of Restorative Dentistry and Cariology, Adhesive Dentistry Research Group, Institute of Dentistry, University of Turku, Turku, Finland
2Turku University Hospital, TYKS, University of Turku, Turku, Finland
3Department of Prosthodontics and Clinical Dentistry, Institute of Dentistry, University of Eastern Finland, Kuopio, Finland
4Department of Oral and Maxillofacial Diseases, University of Helsinki, Helsinki, Finland and Helsinki University Hospital, Helsinki, Finland
5Research Unit of Oral Health Sciences and Medical Research Center Oulu (MRC Oulu), Oulu University Hospital and University of Oulu, Oulu, Finland
6University of Eastern Finland, SIB Labs, Kuopio, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1.8 MB)
Persistent link:
Language: English
Published: Elsevier, 2021
Publish Date: 2021-07-05


Objective: Imperfect polymer formation as well as collagen’s susceptibility to enzymatic degradation increase the vulnerability of hybrid layers over time. This study investigated the effect of new dimethyl sulfoxide (DMSO)-containing pretreatments on long-term bond strength, hybrid layer quality, monomer conversion and collagen structure.

Methods: H₃PO₄-etched mid-coronal dentin surfaces from extracted human molars (n = 8) were randomly treated with aqueous and ethanolic DMSO solutions or following the ethanol-wet bonding technique. Dentin bonding was performed with a three-step etch-and-rinse adhesive. Resin-dentin beams (0.8 mm²) were stored in artificial saliva at 37 °C for 24 h and 2.5 years, submitted to microtensile bond strength testing at 0.5 mm/min and semi-quantitative SEM nanoleakage analysis (n = 8). Micro-Raman spectroscopy was used to determine the degree of conversion at different depths in the hybrid layer (n = 6). Changes in the apparent modulus of elasticity of demineralized collagen beams measuring 0.5 × 1.7 × 7 mm (n = 10) and loss of dry mass (n = 10) after 30 days were calculated via three-point bending and precision weighing, respectively.

Results: DMSO-containing pretreatments produced higher bond strengths, which did not change significantly over time presenting lower incidence of water-filled zones. Higher uniformity in monomer conversion across the hybrid layer occurred for all pretreatments. DMSO-induced collagen stiffening was reversible in water, but with lower peptide solubilization.

Significance: Improved polymer formation and higher stability of the collagen-structure can be attributed to DMSO’s unique ability to simultaneously modify both biological and resin components within the hybrid layer. Pretreatments composed of DMSO/ethanol may be a viable-effective alternative to extend the longevity of resin-dentin bonds.

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Series: Dental materials
ISSN: 0109-5641
ISSN-E: 1879-0097
ISSN-L: 0109-5641
Volume: 37
Issue: 7
Pages: 1083 - 1095
DOI: 10.1016/
Type of Publication: A1 Journal article – refereed
Field of Science: 313 Dentistry
Funding: This work was supported by grant #296653 from the Academy of Finland to AT-M (PI), EVO funding of Turku University Hospital to AT-M (PI).
Copyright information: © 2021 The Author(s). Published by Elsevier Inc. on behalf of The Academy of Dental Materials. This is an open access article under the CC BY-NC-ND license (