Effect of adhesive system type and tooth region on the bond strength to dentin.
OBJECTIVE
This study evaluated the bond strength of two etch-and-rinse adhesive systems (two- and three-step) and a self-etching system to coronal and root canal dentin.


METHODS
The root canals of 30 human incisors and canines were instrumented and prepared with burs. The posts used for luting were duplicated with dual resin cement (Duo-link) inside Aestheti Plus #2 molds. Thus, three groups were formed (n = 10) according to the adhesive system employed: All-Bond 2 (TE3) + resin cement post (rcp) + Duo-link (Dl); One-Step Plus (TE2) + rcp + Dl; Tyrian/One-Step Plus (SE) + rcp + Dl. Afterwards, 8 transverse sections (1.5 mm) were cut from 4 mm above the CEJ up to 4 mm short of the root canal apex, comprising coronal and root canal dentin. The sections were submitted to push-out testing in a universal testing machine EMIC (1 mm/min). Bond strength data were analyzed with two-way repeated measures ANOVA and Tukey's test (p < 0.05).


RESULTS
The relationship between the adhesives was not the same in the different regions (p < 0.05). Comparison of the means achieved with the adhesives in each region (Tukey; p < 0.05) revealed that TE3 (mean +/- standard deviation: 5.22 +/- 1.70) was higher than TE2 (2.60 +/- 1.74) and SE (1.68 +/- 1.85).


CONCLUSIONS
Under the experimental conditions, better bonding to dentin was achieved using the three-step etch-and-rinse system, especially in the coronal region. Therefore, the traditional etch-and-rinse three-step adhesive system seems to be the best choice for teeth needing adhesive endodontic restorations.
São Jose dos Campos Dental School, São Paulo State University, São José dos Campos, SP, Brazil. marquesdemelo@gmail.com
Renata
R
Marques de Melo
Graziela
G
Galhano
Sílvia Helena
SH
Barbosa
Luiz Felipe
LF
Valandro
Carlos Augusto
CA
Pavanelli
Marco Antônio
MA
Bottino
D000134:Acid Etching, Dental; D003481:Cuspid; D001840:Dental Bonding; D003764:Dental Materials / Q000737:chemistry; D003786:Dental Pulp Cavity / Q000648:ultrastructure*; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry / Q000145:classification*; D006801:Humans; D007180:Incisor; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D011176:Post and Core Technique / Q000295:instrumentation; D019279:Resin Cements / Q000737:chemistry; D018915:Root Canal Preparation / Q000379:methods; D013314:Stress, Mechanical; D019228:Tooth Crown / Q000648:ultrastructure*
C103506:Bis-GMA, BPDM, HEMA dental-bonding resin; D003764:Dental Materials; D017220:Dentin-Bonding Agents; C431350:Duo-Link; D008689:Methacrylates; D019279:Resin Cements; C481138:Tyrian SPE; C100742:All-Bond 2