Open Access
CC BY 4.0 · European Journal of General Dentistry 2025; 14(01): 044-050
DOI: 10.1055/s-0044-1787789
Original Article

Hybrid Layer, Shear Bond Strength, and Fracture Patterns of Titanium Dioxide–Doped Phosphate Glass–Filled Universal Dental Adhesives

1   Department of Restorative Dentistry, College of Dental Medicine, University of Sharjah, Sharjah, United Arab Emirates
2   School of Dental Sciences, Universiti Sains Malaysia, Kota Bharu, Kelantan, Malaysia
,
1   Department of Restorative Dentistry, College of Dental Medicine, University of Sharjah, Sharjah, United Arab Emirates
,
1   Department of Restorative Dentistry, College of Dental Medicine, University of Sharjah, Sharjah, United Arab Emirates
,
Ibrahim Mahmood Aziz
1   Department of Restorative Dentistry, College of Dental Medicine, University of Sharjah, Sharjah, United Arab Emirates
,
Ensanya Ali Abou Neel
1   Department of Restorative Dentistry, College of Dental Medicine, University of Sharjah, Sharjah, United Arab Emirates
3   Division of Biomaterials & Tissue Engineering, UCL Eastman Dental Institute, Royal Free Hospital, London, United Kingdom
› Author Affiliations

Funding This study was funded by the University of Sharjah under the Seed Grant scheme (Research Project No. 2201100255).
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Abstract

Objectives The aim of the study was to explore the potential effects of incorporating 5 and 10 wt% of TiO2-doped phosphate glass powder as fillers into the universal adhesive system.

Materials and Methods Human permanent premolars and molars were used in the study. Five and 10 wt% of TiO2-doped phosphate glass powder as fillers were added into the universal adhesive system. Unmodified universal adhesive was used as control. The effects of the added filler in the universal adhesive were examined on hybrid layer formation at the resin composite and dentine interface (mesio-occlusal-distal [MOD] cavities) under scanning electron microscope (SEM), shear bond strength (SBS) of resin composite to dentine using shear bond testing machine, and the patterns of fracture at the resin composite–dentin interface, which were examined under stereomicroscope. The SBS analyses were performed with (8 samples per group, n = 24) and without (8 samples per group, n = 24) 5,000 cycles of thermocycling.

Statistical Analysis One-way analysis of variance (ANOVA) was used to analyze the data of the SBS. For bond strength, the effects of adding fillers into the universal adhesive were analyzed.

Results The SEM images showed that the hybrid layers were similar in all the groups of unmodified and modified adhesives. An ANOVA test revealed that the SBSs of control and modified adhesives were not significantly different before (p = 0.15) or after (p = 0.39) thermocycling for all the groups. The patterns of fracture revealed various types of fracture in all adhesive groups including composite resin, adhesive, and dentine failure. Composite resin fractures are the most encountered pattern of fracture.

Conclusion Adding 5 and 10 wt% of TiO2 into universal adhesive did not adversely affect the hybrid layer, SBS, or mode of failure of composite resin to dentine. The pattern of fracture at the resin composite and dentine interface showed a favorable bonding with more cohesive than adhesive failure, particularly with the 5 wt% glass-modified adhesive group.

Authors' Contributions

A.B.H., H.M.E., and E.A.A.N. conceptualized and designed the study. S.M.F.S. and I.M.A. performed acquisition of data. All the authors revised the manuscript for submission.




Publication History

Article published online:
24 July 2024

© 2024. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/)

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