Silica & Zirconia Bonding Protocols — Step-by-Step Guide

Glass-Based Ceramic (Lithium Discolate) Restoration

Step 1

Apply 5% or 9.5% hydrofluoric acid etching on ceramic for 20-60 sec. Rinse with water and air dry.

Step 2

Cleansing protocol: 30-40% phosphoric acid for 60 seconds, then immerse in Ultrasonic water for 5 minutes, or steam clean, or air water spray for 30 seconds. Rinse with water and air dry.

Step 3

Prime the Surface by applying silane solution for 60 seconds on a frosty (chalky white) surface. Allow the silane to react and evaporate completely. Do not rinse. Gently air dry if needed.

Why do we need etching?

HF dissolves the glassy matrix, creating a microporous surface for micro-mechanical retention.

How should the surface look after etching?

The ceramic should appear frosty, chalky, and dull, indicating a proper etch.

What remains after etching?

Etching leaves residual acids, crystalline precipitates, and salts on the surface.

Why is this important?

These residues can block micro-retentive undercuts and reduce bond strength.

Why do we need ultrasonic cleaning?

It removes residual contaminants and exposes the etched microstructure for optimal bonding.

How should we clean the surface?

Place the restoration in an ultrasonic bath for 2–5min., or use air-water spray or steam cleaning.

When should the restoration be cleaned?

The restoration should be cleaned after try-in to eliminate contamination.

When is the best time to etch?

Etching is preferably performed after try-in to ensure maximum control and cleanliness.

What is the key principle?

A clean and etched surface improves silane coupling and results in stronger bond strength.

Oxide-Based Ceramic (Zirconia) Restorations

Step 1

Particle abrade with 27 um aluminum oxide at 40 psi (2.75 bar). Rinse with water and air dry.

Step 2

Prime the Surface. Apply zirconia primer (MDP) for 20sec.  Dry the inside surface thoroughly for 5 seconds.

Why do we need sandblasting (air abrasion) for zirconia?

Airborne-particle abrasion creates a roughened surface, increasing surface energy and providing micro-mechanical retention for improved bonding.

Why is MDP primer required for zirconia?

MDP chemically bonds to zirconia by forming a stable bond with zirconium oxide, enhancing adhesion between the restoration and resin cement.

Why is this combination important?

Sandblasting provides micro-mechanical retention, while MDP creates chemical bonding, resulting in a strong and durable adhesion.