Two-Year Bonding Performances of a Universal Adhesive After Dentin Pre-Treatment With Two-Step Silver-Containing...

Area of Science:

• Dental Materials Science
• Adhesive Dentistry
• Biomaterials

Background:

• Universal adhesives are widely used in composite resin restorations.
• Dentin matrix metalloproteinases (MMPs) can degrade the hybrid layer, compromising bond longevity.
• Silver-containing solutions are explored for their potential antimicrobial and MMP-inhibiting properties.

Purpose of the Study:

• To assess the long-term (2-year) effects of dentin pre-treatment with two-step silver solutions on universal adhesive bond strength.
• To characterize the chemo-morphology and matrix metalloproteinases (MMPs) activity at the adhesive interface.
• To evaluate the influence of pre-treatment on microtensile bond strength (µTBS) after artificial aging.

Main Methods:

• Sixty human molars were divided into self-etch (SE) and etch-and-rinse (ER) groups.
• Dentin was pre-treated with Riva Star or Riva Star Aqua before universal adhesive application.
• Microtensile bond strength (µTBS), SEM/EDS, and in-situ zymography were performed at baseline and after 2 years of artificial aging.

Main Results:

• Dentin pre-treatment with silver solutions significantly reduced µTBS compared to controls after 2 years.
• Artificial aging decreased bond strength in all groups; ER groups showed higher strength than SE groups.
• No silver ions were detected, but Riva Star significantly decreased MMPs activity, indicating product-dependent effects.

Conclusions:

• Two-step silver-containing solutions as dentin pre-treatment negatively affected the 2-year bonding performance of universal adhesives.
• The tested silver solutions did not improve long-term bond durability despite MMPs activity reduction.
• Bonding outcomes are dependent on the specific silver-containing product used.