Abstract
Objective The main purpose of this study was to evaluate the effect of dentin pretreatment
with 8% arginine on the immediate and 6-month bond strength (BS) of adhesive systems
and surface morphology of dentin.
Materials and Methods Dentin bovine specimens (5 × 5 mm) were allocated into following pretreatments: without
pretreatment (conventional technique, C) or exposure to arginine solution (A) for
5 minutes prior to tooth restoration. The adhesive procedure was performed using (n = 12): 3-step etch-and-rinse adhesive (Scotchbond Multipurpose—SBMP [C+SBMP and A+SBMP]);
2-step etch-and-rinse adhesive (Single Bond 2 - SB [C+SB and A+SB]); or 2-step self-etch
adhesive (Clearfil SE Bond - CSEB [C+CSEB and A+CSEB]). After 24 hours, the composite
resin restorations were evaluated immediately and after 6 months of water storage
using a microshear test and fracture pattern. The dentin surface exposed to A was
assessed by scanning electron microscopy (SEM). The immediate BS data were submitted
to a two-way analysis of variance and Tukey's test, and the long-term BS results were
analyzed using Kruskal–Wallis and Dunn tests (α = 0.05).
Results There was a significant decrease in immediate and 6-month BS for the A+SB and A+CSEB
groups, which differed statistically from the C group. The fracture pattern was predominantly
adhesive for SB and CSEB adhesive for C and A. The SEM images presented a different
conditioning pattern of the dentin exposed to A.
Conclusion The dentin pretreatment with arginine interfered negatively in the immediate and
long-term BS of the simplified adhesive system. However, the SBMP adhesive was not
affected by arginine pretreatment presenting the most satisfactory results.
Keywords
arginine - dentin - adhesive systems - adhesion - dentin-bonding agents
