Bond strength and quality of the hybrid layer of one-step self-etch adhesives applied with agitation on dentin.
OBJECTIVE
This study evaluated the effect of the application mode on the microtensile resin-dentin bond strength (microTBS) and silver nitrate uptake (SNU) of three one-step self-etch adhesives systems (Clearfil S3 Bond [S3], Xeno III [XE] and Adper Prompt L-Pop [AD]).


METHODS
The occlusal enamel of 30 caries-free extracted molars was removed with a slow-speed diamond saw under copious water-cooling in order to expose a flat dentin surface. The adhesives were applied passively or with agitation. After light-curing (600 mW/cm2 for 10 seconds), composite buildups were constructed incrementally and the specimens were stored in water (37 degrees C/24 hours). The specimens were longitudinally sectioned in the "x" and "'y" direction to obtain bonded sticks (0.8 mm2) to be tested immediately in tension at 0.5 mm/minute. For SNU, two bonded sticks from each tooth were coated with nail varnish, placed in silver nitrate and polished down with SiC paper. The microTBS and SNU data were submitted to two-way ANOVA and Tukey's test (alpha=0.05).


RESULTS
Regarding the microTBS, only the main factor mode of application was statistically significant (p = 0.01). All adhesives showed higher microTBS when applied with agitation. Regarding SNU, only the main factor adhesive was statistically significant (p = 0.001). A higher amount of silver nitrate uptake, located in both the hybrid and adhesive layer, occurred for AD, regardless of the mode of application.


CONCLUSIONS
Application with agitation on the dentin surface is a clinical tool capable of improving the resin-dentin bond strength of one-step self-etch adhesives; however, this clinical approach does not improve the hybrid layer resistance to silver nitrate uptake.
do Amaral
Roberto César
RC
Department of Dental Materials and Restorative Dentistry, Universidade do Oeste de Santa Catarina, Joaçaba, SC, Brazil.
Stanislawczuk
Rodrigo
R
Zander-Grande
Cristiana
C
Gagler
Diego
D
Reis
Alessandra
A
Loguercio
Alessandro Dourado
AD
D000134:Acid Etching, Dental; D001840:Dental Bonding; D003799:Dental Stress Analysis; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D019279:Resin Cements / Q000737:chemistry*; D012835:Silver Nitrate / Q000737:chemistry; D013718:Tensile Strength; D014732:Vibration
C505694:Clearfil S3 Bond; D017220:Dentin-Bonding Agents; C408584:Prompt L-Pop; D019279:Resin Cements; C487957:Xeno III; D012835:Silver Nitrate