A 2-year evaluation of moisture on microtensile bond strength and nanoleakage.
OBJECTIVE
This study evaluated the effect of moisture on the resin-dentin mu-bond strength (BS) and silver nitrate uptake (SNU) of three adhesive systems (Single Bond, One-Step and Syntac Single Component) soon after bonding (IM) and after 2 years of water storage (2Y).


METHODS
Dentin surfaces were bonded on a dry (D), moist (W) or over-wet surfaces (OW). After restorations were constructed, specimens were stored in water (37 degrees C/24h). Resin-dentin sticks were prepared (0.8mm(2)) and they were divided for immediate (IM) and 2-year storage (2Y) testing. Half of the specimens from each period of time were tested in tension at 0.5mm/min and the other half was immersed in silver nitrate and examined by SEM-EDX. The data was analyzed by three-way repeated measures ANOVA and Tukey's tests (alpha=0.05).


RESULTS
The overall BS (MPa) in the IM group under W condition was higher than in D and OW groups. After 2Y, the BS in W was lower than in the IM group, however higher than in the D and OW for OS and SB. The overall silver nitrate deposition (%) in the IM group under D, W and OW were similar. In the 2Y groups, the nanoleakage was higher than IM groups, however the increase was less pronounced in the W condition.


CONCLUSIONS
Higher BS and a significantly lower nitrate uptake were observed for IM groups, for OS and SB. Under W conditions, the BS reduction over time was less pronounced and less nitrate uptake occurred.
Reis
A
A
School of Dentistry, University of Oeste de Santa Catarina, Joaçaba, SC, Brazil.
Grande
R H M
RH
Oliveira
G M S
GM
Lopes
G C
GC
Loguercio
A D
AD
D000042:Absorption; D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate; D001840:Dental Bonding; D003763:Dental Leakage; D003799:Dental Stress Analysis; D003804:Dentin; D003806:Dentin Permeability; D017220:Dentin-Bonding Agents; D004577:Electron Probe Microanalysis; D006801:Humans; D008689:Methacrylates; D008964:Molar, Third; D012044:Regression Analysis; D019279:Resin Cements; D012835:Silver Nitrate / Q000737:chemistry; D013718:Tensile Strength; D013997:Time Factors; D014867:Water
C103506:Bis-GMA, BPDM, HEMA dental-bonding resin; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D019279:Resin Cements; C078484:Syntac dentine adhesive; C115612:single bond; D014867:Water; D017438:Bisphenol A-Glycidyl Methacrylate; D012835:Silver Nitrate