Six-month storage-time evaluation of one-bottle adhesive systems to dentin

Purpose : The goal of this study was to evaluate the 1-week, 3-month, and 6-month performance of eight commercially available one-bottle adhesive systems to dentin.
Materials and Methods : Lingual and buccal surfaces from human third molars were ground wet on 600-grit SiC paper to obtain a flat dentinal surface. The specimens were randomly divided into 24 groups (n = 10), which were established to measure the shear bond strengths of Bond-1 (B1), ONE-STEP (OS), OptiBond SOLO (OP), Prime & Bond 2.1 (PB), Single Bond (SB), STAE (ST), Syntac Sprint (SS), and Tenure Quick (TQ) after 1-week, 3-month, and 6-month water storage at 37°C. One-bottle adhesives were applied according to manufacturers' instructions and Z100 composite cylinders were applied on the bonded dentinal surfaces. The 3-month water-storage groups were thermocycled for 1500 cycles at 5°C and 55°C and 6-month groups for 3000 cycles. After storage periods, specimens were tested in shear in a universal testing machine (0.5 mm/min). Results were statistically analyzed by analysis of variance and Tukey test.
Results : The changes in shear bond strengths were not uniform over time. Over the test period, OS, PB, SB, and SS exhibited bond strength stability, however, SS presented low bond strengths on all tested periods. A significant decrease in bond strength was observed for B1, OP, ST, and TQ after the 6-month storage period.
CLINICAL SlGNlFlCANCE
Bonding is only clinically significant if long lasting. Three one-bottle adhesive systems presented remarkable stability over the storage period and thermal cycling regimen. However, decreased bond strengths were verified for the other bonding agents.