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Published on: May 17, 2020
Repair Bond Strength of Aged Bulk-Fill Composites: Influence of Different Primers and Direction of Debonding Stress
P Ahlholm1, F Staxrud2, K Sipilä3,4
1Department of Oral and Maxillofacial Diseases, Helsinki University Hospital, Helsinki, Finland.
Objective:
This study aimed to assess the hydrolytic stability of the adhesive interface between repaired bulk-fill and bulk-fill resin composites after 12 months of water storage.
Materials And Methods:
Bulk-fill resin composite specimens were bonded to smooth substrate surfaces using three different primer/bonding systems. A total of 35 specimens were prepared for shear bond strength (SBS) testing, and 30 specimens for micro-tensile bond strength (μTBS) testing. The specimens were aged in water at 37°C for 12 months, after which SBS and μTBS were evaluated.
Results:
The mean SBS ranged from 6.0 to 14.9 MPa, with the highest values observed for the Ceramic primer. The mean μTBS ranged from 0 to 7.8 MPa, with the Composite primer yielding the highest values. Both primers outperformed the three-step etch-and-rinse adhesive in terms of bond strength.
Conclusions:
The Ceramic primer (containing silane) and the Composite primer exhibited superior adhesive performance compared to the three-step etch-and-rinse adhesive, demonstrating better long-term bond stability.
Clinical Relevance:
The findings suggest that using Ceramic or Composite primers can enhance the durability of repaired bulk-fill composite restorations, improving adhesive stability and long-term clinical outcomes.
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