Repairing Old Composite: Silane and Not Curing the Bonding Agent

فارسی

One of the clinical challenges is bonding new composite to old composite. This episode reviews a laboratory study that looked for the protocol with the highest bond strength in these restorations.

What the study did

The composites were aged with thermocycling. Two things were then compared: with or without silane, and a bonding agent that was cured or not cured before the new composite was placed.

Silane

Silane significantly increased the bond strength between the old and the new composite and should not be left out of the repair protocol.

Not curing the bonding agent

Not curing the bonding agent before placing the new composite gave higher strength. Here the bonding agent acts like a wetting agent and fills the microscopic irregularities of the surface. This effect was independent of silane and was seen in the groups with silane and in the groups without silane.

Proposed protocol

• Roughening the surface of the old composite with a bur
• Applying silane
• Applying the bonding agent without light-curing
• Placing the new composite and final curing

Summary

Silane and not curing the bonding agent both increase the strength of the repair of old composite.

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