Bonding super translucent multilayered monolithic zirconia to different foundation materials: an invitro study.

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Adhesive Dentistry

Background:

• Monolithic zirconia restorations require optimal bonding for longevity.
• Surface conditioning and substrate type significantly influence bond strength.

Purpose of the Study:

• To evaluate the effect of surface conditioning (milling vs. sandblasting with primer) on monolithic zirconia.
• To assess the influence of different substrates (dentin, composite, RMGI) on bond strength.
• To determine the interaction between surface treatment and substrate on shear bond strength.

Main Methods:

• Forty-eight monolithic zirconia discs underwent two surface treatments: milled with primer (P) or sandblasted with primer (SP).
• Specimens were bonded to dentin, composite, or resin-modified glass ionomer (RMGI).
• Shear bond strength (SBS) was tested after 6 months of water storage and 10,000 thermal cycles.

Main Results:

• The sandblasted and primed dentin group (DSP) exhibited the highest mean SBS (22.65 MPa).
• The milled and primed dentin group (DP) showed the second-highest SBS (18.61 MPa).
• Resin-modified glass ionomer (RMGI) groups (GSP, GP) displayed the lowest SBS (around 4.7 MPa).

Conclusions:

• Sandblasting followed by universal primer application is a recommended surface treatment for monolithic zirconia.
• Dentin is the most reliable substrate for bonding monolithic zirconia, followed by composite.
• Surface conditioning and substrate choice are critical factors for successful zirconia bonding.