Effects of water storage on bond strength and dentin sealing ability promoted by adhesive systems.
OBJECTIVE
To evaluate the dentin bond strength (BS) and sealing ability (SA) promoted by adhesive systems after 24 h or 6 months of water storage.


METHODS
The tested adhesive systems were: one three-step etch-and-rinse adhesive (Adper Scotchbond Multi-Purpose, SBMP) and three single-step self-etching systems (Adper Easy Bond, Bond Force, and G-Bond Plus). Bovine incisors were used for both evaluations, BS (n = 11) and SA (n = 5). To examine BS, the buccal surface was ground with SiC paper to expose a flat dentin surface. After adhesive application, a block of resin composite was incrementally built up over the bonded surface and sectioned into sticks. These bonded specimens were subjected to microtensile bond strength testing after 24 h and 6 months of water storage using a universal testing machine. For SA analysis, enamel was removed from the buccal surfaces. The teeth were connected to a device to measure the initial SA (10 psi), and the second measurement was taken after treating dentin with EDTA. Afterwards, the adhesive systems were applied to dentin and the SA was re-measured for each adhesive after 24 h and 6 months of water storage. The SA was expressed in terms of percentage of dentinal sealing. BS and SA data were submitted to two-way ANOVA and Tukey's test (α = 0.05).


RESULTS
All adhesives showed a reduction of SA after 6 months of water storage. The SA promoted by self-etching adhesives was higher than that of SBMP. No adhesive system showed a reduction of the BS after 6 months.


CONCLUSIONS
Sealing ability was affected by water storage, while no changes in microtensile bond strength were observed after 6 months of water storage. The single-step self-etching systems showed greater sealing ability than did SBMP, even after 6 months of storage in water.
Department of Restorative Dentistry, State University of Campinas, Piracicaba, Brazil.
Renata Bacelar
RB
Cantanhede de Sá
Adriana
A
Oliveira Carvalho
Regina Maria
RM
Puppin-Rontani
Glaúcia Maria
GM
Ambrosano
Toru
T
Nikaido
Junji
J
Tagami
Marcelo
M
Giannini
D000818:Animals; D002417:Cattle; D001840:Dental Bonding; D003763:Dental Leakage / Q000517:prevention & control*; D003799:Dental Stress Analysis; D003806:Dentin Permeability; D017220:Dentin-Bonding Agents / Q000737:chemistry; D004356:Drug Storage; D019279:Resin Cements / Q000737:chemistry; D013718:Tensile Strength; D014867:Water
D017220:Dentin-Bonding Agents; D019279:Resin Cements; D014867:Water