Tensile bond strength of a flowable composite resin to ER:YAG-laser-treated dentin.
OBJECTIVE
This in vitro study evaluated the influence of a flowable composite resin (FCR) on the tensile bond strength of resin to dentin treated with the Er:YAG Laser (L) and diamond bur (DB).


METHODS
Ninety dentin surfaces obtained from 45 third molars were ground and randomly divided into six groups (n = 15): G1-DB, G2-DB+FCR, G3-L (100 mJ, 10 Hz, 37.04 J/cm2), G4-L (100 mJ, 10 Hz, 37.04 J/cm2)+FCR, G5-L (250 mJ, 2 Hz, 92.60 J/cm2), and G6-L (250 mJ, 2 Hz, 92.60 J/cm2)+FCR. After surface etching with 37% phosphoric acid and the application of an adhesive system, inverted conical specimens were prepared with a hybrid composite resin. In groups G2, G4, and G6 a FCR was placed before the hybrid composite resin. After 24 hours-storage in distilled water, the tensile test was performed in a universal testing machine (0.5 mm/minute, 500 N).


RESULTS
Data were submitted to Kruskal Wallis test (P = 0.01). The mean bond strength values (MPa+/-SD) were: G1-13.54 (+/-2.99), G2-14.67 (+/-2.32), G3-9.49 (+/-3.09), G4-14.60 (+/-2.76), G5-8.97 (+/-3.89), and G6-13.02 (+/-2.18). Groups G1 and G2 presented the highest bond strength values, which were statistically similar to those of G4 and G6. The groups treated with laser and without the FCR (G3 and G5) showed the lowest shear bond strength values.


CONCLUSIONS
FCR can increase the adhesion to dentin treated with Er:YAG laser within different parameters.
Donadio-Moura
Juliana
J
School of Dentistry, University of São Paulo (USP), São Paulo, SP 05508-900, Brazil.
Gouw-Soares
Sheila
S
de Freitas
Patricia M
PM
Navarro
Ricardo S
RS
Powell
Lynn G
LG
Eduardo
Carlos de P
Cde P
D000268:Adhesiveness / Q000528:radiation effects*; D000328:Adult; D000535:Aluminum; D003188:Composite Resins; D001840:Dental Bonding; D003804:Dentin / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D004871:Erbium; D006801:Humans; D066298:In Vitro Techniques; D007834:Lasers; D008689:Methacrylates; D013718:Tensile Strength; D015019:Yttrium
D003188:Composite Resins; C420130:Excite cement; D008689:Methacrylates; C121818:Tetric ceram; C452226:tetric flow composite resin; C503779:yttrium-aluminum-garnet; D015019:Yttrium; D004871:Erbium; D000535:Aluminum