Effect of a silane coupling agent on composite repair strengths

Abstract

Purpose: To evaluate the use of a silane coupling agent (Silane Bond Enhancer) for repair of a glass-filled hybrid resin composite (Herculite XR).

Materials and methods: Composite specimens (n = 20) were either air-abraded (AA) with an intraoral sandblaster (Microetcher), etched with 9.6% hydrofluoric acid (HF) (Porcelain Etch Gel), or treated with both methods (AA/HF). A silane coupling agent was applied to half of the specimens after these initial surface treatments. Composite repairs were completed by application of a phosphonate ester bonding agent (Bondlite) and resin composite (XRV Herculite). Transverse strengths of repaired specimens and intact (control) specimens were determined using an Instron.

Results: The mean bond strengths of repaired specimens ranged from 41% to 62% of the composite's cohesive strength. All repair strengths were significantly lower than the cohesive strength, but were not significantly different from each other. Silanation slightly improved the transverse strength of specimens repaired using the HF and AA/HF methods, but not those repaired using the AA procedure.