Can the durability of one-step self-etch adhesives be improved by double application or by an extra layer of hydrophobic resin?
OBJECTIVE
This study evaluated the immediate and 6-month resin-dentin micro-bond strength (microTBS) of one-step self-etch systems (Adper Prompt L-Pop [AD] 3M ESPE; Xeno III [XE] Dentsply De Trey; iBond [iB] Heraeus Kulzer) under different application modes.


METHODS
Dentin oclusal surfaces were exposed by grinding with 600-grit SiC paper. The adhesives were applied according to the manufacturer's directions [MD], or with double application of the adhesive layer [DA] or following the manufacturer's directions plus a hydrophobic resin layer coating [HL]. After applying the adhesive resins, composite crowns were built up incrementally. After 24-h water storage, the specimens were serially sectioned in "x" and "y" directions to obtain bonded sticks of about 0.8mm2 to be tested immediately [IM] or after 6 months of water storage [6M] at a crosshead speed of 0.5mm/min. The data from each adhesive was analyzed by a two-way repeated measures ANOVA (mode of application vs. storage time) and Tukey's test (alpha=0.05).


RESULTS
The adhesives performed differently according to the application mode. The DA and HL either improved the immediate performance of the adhesive or did not differ from the MD. The resin-dentin bond strength values observed after 6 months were higher when a hydrophobic resin coat was used than compared to those values observed under the manufacturer's directions.


CONCLUSIONS
The double application of one-step self-etch system can be safety performed however the application of an additional hydrophobic resin layer can improve the immediate resin-dentin bonds and reduce the degradation of resin bonds over time.
Reis
Alessandra
A
Department of Restorative Dentistry, Universidade Estadual de Ponta Grossa, Avenida General Carlos Cavalcanti, 4748, Bloco M, Sala 64A, Uvaranas, Ponta Grossa, PR 84030-900, Brazil. reis_ale@hotmail.com
Albuquerque
Maurício
M
Pegoraro
Mariana
M
Mattei
Gracielle
G
Bauer
José Roberto de Oliveira
JR
Grande
Rosa Helena Miranda
RH
Klein-Junior
Celso Afonso
CA
Baumhardt-Neto
Ricardo
R
Loguercio
Alessandro D
AD
D003188:Composite Resins / Q000737:chemistry; D003442:Crowns; D001840:Dental Bonding; D003804:Dentin / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008422:Materials Testing; D019279:Resin Cements / Q000737:chemistry*; D013314:Stress, Mechanical; D013499:Surface Properties; D016019:Survival Analysis; D013718:Tensile Strength; D013997:Time Factors; D014867:Water / Q000737:chemistry
C438313:Clearfil SE Bond; D003188:Composite Resins; D017220:Dentin-Bonding Agents; C444701:Filtek Z250; C408584:Prompt L-Pop; D019279:Resin Cements; C487957:Xeno III; C477386:iBond; D014867:Water