Effect of chlorhexidine concentrations on micro-shear bond strength of self-etch adhesive to normal and caries-affected dentin.
OBJECTIVE
To evaluate the effect of different chlorhexidine concentrations on bond strength of resin composite to normal and caries-affected dentin using a self-etch primer adhesive.


METHODS
Thirty carious human molars were ground to expose flat dentin surfaces containing caries-affected surrounded by normal dentin. The teeth were divided into three groups. One group received no chlorhexidine pretreatment (control). The second and third groups received 2% or 5% chlorhexidine pretreatments, respectively before applying the self-etch primer adhesive (Clearfil SE Bond). Resin composite was applied to caries-affected dentin and to normal dentin on the same tooth with the aid of polyethylene tubes (0.9 mm diameter and 0.7 mm height). For micro-shear bond strength testing, each tooth was secured in a specially designed attachment jig to hold the specimens to the universal testing machine. Load was applied by the testing machine through a wire loop adjusted to the bonded interface at a crosshead speed of 0.5 mm/minute. Micro-shear bond strength was calculated and mode of failure was examined with a x40 stereomicroscope.


RESULTS
Statistical analysis revealed insignificant differences between control, 2% and 5% chlorhexidine pretreatment for normal as well as for caries-affected dentin groups. Also, there were insignificant differences in bond strength values between normal and caries-affected dentin for each treatment modality. Adhesive failure was the most common mode of failure.
Department of Restorative Dentistry, Faculty of Oral and Dental Medicine, Cairo University, 29 El-Zahraa St. Dokki, Giza, Cairo, 12311 Egypt. enasmobarak@hotmail.com
Enas H
EH
Mobarak
Dalia I
DI
El-Korashy
David H
DH
Pashley
D000268:Adhesiveness; D000891:Anti-Infective Agents, Local / Q000737:chemistry*; D002710:Chlorhexidine / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003731:Dental Caries / Q000473:pathology*; D003764:Dental Materials / Q000737:chemistry; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000648:ultrastructure*; D006801:Humans; D055115:Light-Curing of Dental Adhesives; D008422:Materials Testing; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D013314:Stress, Mechanical; D013499:Surface Properties
D000891:Anti-Infective Agents, Local; C438313:Clearfil SE Bond; D003188:Composite Resins; D003764:Dental Materials; C444701:Filtek Z250; D019279:Resin Cements; D002710:Chlorhexidine