Amalgam shear bond strength to dentin using single-bottle primer/adhesive systems.

Area of Science:

• Dental Materials Science
• Adhesive Dentistry
• Restorative Dentistry

Background:

• Dental adhesives are crucial for bonding restorative materials to tooth structure.
• Evaluating the shear bond strength (SBS) of amalgam to dentin is essential for clinical success.
• Various single-bottle and multi-component adhesive systems exist, each with different bonding mechanisms.

Purpose of the Study:

• To compare the in vitro shear bond strengths (SBS) of a spherical amalgam alloy to dentin.
• To assess the performance of several single-bottle primer/adhesive systems, both alone and with supplemental amalgam bonding agents.
• To compare these systems against two three-component adhesive systems.

Main Methods:

• Extracted human third molars were prepared to expose flat dentin surfaces.
• Dentin surfaces were treated with nine different adhesive systems (n=12 per group).
• Amalgam was condensed onto treated dentin, followed by water storage, thermocycling, and shear bond strength testing.

Main Results:

• Scotchbond Multi-Purpose Plus with light curing (S + V) and Single Bond with 3M RelyX ARC (SBX) exhibited the highest mean SBS values (10.3 ± 2.3 MPa and 10.2 ± 3.5 MPa, respectively).
• OptiBond Solo (SOL) and Prime & Bond 2.1 with Amalgam Bonding Accessory Kit (PBA) showed comparable bond strengths to three-component systems (SBMP and S+).
• Single-bottle systems One-Step (OS), Single Bond (SB), and Prime & Bond 2.1 (PB) demonstrated significantly lower bond strengths.

Conclusions:

• The combination of Single Bond with 3M RelyX ARC (SBX) and Scotchbond Multi-Purpose Plus with light curing (S + V) significantly enhanced amalgam-to-dentin shear bond strength.
• Some single-bottle adhesives, when used with specific amalgam bonding agents, can achieve bond strengths comparable to multi-component systems.
• Adhesive system selection plays a critical role in achieving durable amalgam restorations.