Bonding Done Right
In direct composite restorations, a well-executed bond supports the strength and longevity of the restoration. Universal adhesives such as G-Premio BOND offer flexibility across etching approaches. Here is a practical look at enamel, dentin and the smear layer, and how to choose a bonding protocol.
Etching Techniques
| Total etch | Selective etch | Self etch |
|---|---|---|
| Phosphoric acid on enamel (10–15 sec) and dentin (about 15 sec). | Phosphoric acid on enamel only (10–15 sec). | No separate phosphoric-acid etching of enamel or dentin. |
Etched enamel
Phosphoric acid removes the superficial aprismatic enamel and exposes enamel rods, creating a surface for micromechanical bonding.
Etched dentin
| Dry dentin | Hydrated dentin |
|---|---|
| Overdrying can collapse exposed collagen fibres and reduce adhesive infiltration. | Properly managed moisture keeps the collagen network open for adhesive infiltration. |
After dentin etching, avoid excessive drying. Follow the adhesive manufacturer’s instructions for moisture control, application and curing.
Smear Layer
Preparation leaves a smear layer of debris on dentin. Total-etch protocols remove it with phosphoric acid. In selective-etch and self-etch approaches, the adhesive interacts with the smear layer rather than removing it with a separate dentin acid-etch step. Air abrasion may be considered where appropriate to the clinical case and product instructions.
GC’s expertise in bonding
GC describes its universal bonding systems as suitable for total-etch, selective-etch and self-etch techniques. They feature HEMA-free formulations and the functional monomers 4-MET, MDP and MDTP. Check the current product instructions for precise indications and application steps.
| G-Premio BOND | G2-Bond Universal |
|---|---|
| One-step, one-bottle universal adhesive system. | Two-step, two-bottle system with separate primer and bond. |
For predictable results, choose the etching strategy that fits the tooth surface, maintain good isolation, and use the adhesive exactly as directed. This educational guide does not replace clinical judgment or the manufacturer’s instructions.
0 comments