Influence of a hydrophobic resin coating on the immediate and 6-month dentin bonding of three universal adhesives

• The objective was to study the influence of a hydrophobic resin coating on the 6-month microtensile dentin bond strengths (μTBS) and nanoleakage (NL) of three universal adhesives applied in self-etch or in etch-and-rinse mode.
• The universal adhesives Scotchbond Universal Adhesive (3M ESPE); All-Bond Universal (Bisco Inc.); and G-Bond Plus or G-ænial Bond (GC Co.) were applied under etch-and-rinse or self-etch modes. The use of a “hydrophobic resin coating” (with or without Heliobond, Ivoclar Vivadent), and “storage time” (24h or 6m) were the other factors.
• The application of a hydrophobic resin coating improved the 6m performance of all three universal adhesives when applied in SE mode.

ObjectiveTo test the influence of a hydrophobic resin coating (HC) on the immediate (24h) and 6-month (6m) microtensile dentin bond strengths (μTBS) and nanoleakage (NL) of three universal adhesives applied in self-etch (SE) or in etch-and-rinse (ER) mode.MethodsSixty caries-free extracted third molars were assigned to 12 experimental groups resulting from the combination of the factors “adhesive system” (Scotchbond Universal Adhesive [SBU], 3M ESPE; All-Bond Universal [ABU], Bisco Inc.; and G-Bond Plus [GBP], GC Corporation); “adhesive strategy” (SE or ER); “hydrophobic resin coating” [HC] (with or without Heliobond, Ivoclar Vivadent); and “storage time” (24h or 6m). Specimens were prepared for μTBS testing – (24h) half of the beams were immediately tested under tension; and (6m) the other half was stored in distilled water (37 °C) for 6m prior to testing. For each tooth, two beams were randomly selected for NL evaluation for both evaluation times. Data were analyzed for each adhesive system using three-way ANOVA and Tukey's post-hoc test (α = 0.05).ResultsμTBS: (24h): In SE mode, HC resulted in statistically greater mean μTBS for all adhesives. (6m): When HC was not used the mean μTBS for SBU/ER, ABU/ER, GBP/ER and SBU/SE decreased significantly.NL: (24h): SBU/ER, ABU/ER and GBP/SE resulted in a significant reduction in NL when HC was applied. (6m): No significant reduction was observed for SBU/ER or for SBU/SE regardless of the use of HC.SignificanceThe application of a hydrophobic resin coating improved the 24h and the 6m performances of all three adhesives systems in SE mode.