Effect of water contamination on the shear bond strength of five orthodontic adhesives.
OBJECTIVE
To evaluate the shear bond strength and site of failure of brackets bonded to dry and wet enamel.


METHODS
50 teeth were divided into ten groups of 5 teeth each (10 surfaces). In half the groups enamel was kept dry before bonding, and in the other half distilled water was applied to wet the surface after etching. The following groups were established: 1) Acid/Transbond-XT (dry/wet) XT; 2) Transbond Plus Self Etching Primer (TSEP)/Transbond-XT paste (dry/wet); 3) Concise (dry), Transbond MIP/Concise (wet), 4) FujiOrtho-LC (dry/wet); 5) SmartBond (dry/wet). Brackets were bonded to both buccal and lingual surfaces. Specimens were stored in distilled water (24 hours at 37 degrees C) and thermocycled. Brackets were debonded using a Universal testing machine (cross-head speed 1 mm/min). Failure sites were classified using a stereomicroscope.


RESULTS
No significant differences in bond strength were detected between the adhesives under wet and dry conditions except for SmartBond, whose bond strength was significantly lower under dry conditions. For all the adhesives most bond failures were of mixed site location except for Smartbond, which failed at the adhesive-bracket interface.


CONCLUSIONS
Under wet conditions the bonding capacity of the adhesives tested was similar than under dry conditions, with the exception of SmartBond which improved under wet conditions.
Vicente
Ascensión
A
Orthodontic Teaching Unit, University of Murcia, Murcia, Spain. ascenvi@um.es
Toledano
Manuel
M
Bravo
Luis A
LA
Romeo
Alejandro
A
de la Higuera
Blanca
B
Osorio
Raquel
R
D001840:Dental Bonding; D003738:Dental Cements; D006801:Humans; D006813:Humidity; D066298:In Vitro Techniques; D014867:Water
D003738:Dental Cements; D014867:Water