Loading Effect on µTBS of All-In-One Adhesives – Direct Bonding

Objectives: The purpose of this in vitro study is to use microtensile bond strength (µTBS) test to compare an experimental unfilled single-component adhesive containing a proprietary organophosphate and hydrophobic monomers (Danville Materials) to commercial products by using each in direct bonding of AP-X to dentin with and without mechanical loading on each system.

Methods: Dentin surfaces of sound human third molars were exposed using #600 SiC paper, treated with four all-in-one adhesives: Danville Experimental (Danville Materials); G Bond (GC); TriS Bond (Kuraray); AdheseOne (Vivadent) and a total etch adhesive, Prelude (Danville). Composite resin (AP-X, Kuraray) build ups were created. The samples were divided into two subgroups and the first subgroups only were subjected to mechanical fatique loading (5x10⁴ ; 50N at 0.2 Hz). After storage at 37°C for 1 week, µTBS test was performed, data was calculated as MPa and statistically analyzed using Multivariate Analysis of Variance. Multiple comparisons were done using t-test.

Results: µTBS of tested materials with/without loading were as follows (Mean±SD;MPa): Danville Experimental: 11.92±2.52/22.72±3.92; GBond: 22.91±1.89/33.22±5.55; TriS Bond: 19.46±3.87/27.65±4.28; AdheseOne: 16.67±2.15/19.8±3.86; Prelude Total Etch: 31.21±2.54/40.92±3.51.

Conclusion: Mechanical loading significantly decreased µTBS of the tested materials (p=0.000). Prelude Total Etch showed the highest bond strength values when compared to the all-in-one adhesives (p<0.01). G Bond and TriS Bond showed significantly higher bond strength values than Danville Experimental and AdheseOne (p<0.01).