Effect of chlorhexidine application on shear bond strength of brackets bonded with a resin-modified glass ionomer.
BACKGROUND
The purpose of study was to assess the effect of chlorhexidine application on the shear bond strength and bond failure site of a resin-modified glass ionomer (Fuji Ortho LC, GC Europe, Leuven, Belgium).


METHODS
Forty-five bovine permanent mandibular incisors were randomly divided into 3 groups of 15. Group 1 had no chlorhexidine treatment and served as the control; groups 2 and 3 had chlorhexidine application immediately before and 1 week before bonding, respectively. Stainless steel brackets (DB, Leone, Sesto Fiorentino, Italy) were bonded with the resin-modified glass ionomer. After bonding, all samples were stored in distilled water for 24 hours and subsequently tested in a shear mode on a testing machine. Analysis of variance (ANOVA) and the Scheffé test were applied to determine significant differences in the shear bond strength values, and the chi-square test was used to determine significant differences in the adhesive remnant index scores among the groups. Significance for all statistical tests was predetermined at P < .05.


RESULTS
Group 1 (no chlorhexidine application) showed significantly higher shear bond strength values than group 2 (chlorhexidine applied immediately before bonding). No significant differences were found between groups 1 and 3 (chlorhexidine applied 1 week before bonding). Moreover, significant differences in debond locations were found among the 3 groups.


CONCLUSIONS
Chlorhexidine application immediately before bonding significantly lowered the bond strength values of Fuji Ortho LC but did not affect its bond strength when applied 1 week before bonding.
Cacciafesta
Vittorio
V
Department of Orthodontics, University of Insubria, Varese, Italy. vcacciafesta@hotmail.com
Sfondrini
Maria Francesca
MF
Stifanelli
Paola
P
Scribante
Andrea
A
Klersy
Catherine
C
D000180:Acrylic Resins; D000269:Adhesives; D000538:Aluminum Silicates; D000704:Analysis of Variance; D000818:Animals; D000891:Anti-Infective Agents, Local; D002417:Cattle; D002710:Chlorhexidine; D003722:Dental Alloys; D001840:Dental Bonding; D003799:Dental Stress Analysis; D005899:Glass Ionomer Cements; D009067:Mouthwashes; D016910:Orthodontic Brackets; D033081:Shear Strength; D013193:Stainless Steel; D018709:Statistics, Nonparametric; D013997:Time Factors
D000180:Acrylic Resins; D000269:Adhesives; D000538:Aluminum Silicates; D000891:Anti-Infective Agents, Local; D003722:Dental Alloys; C095451:Fuji Ortho LC; D005899:Glass Ionomer Cements; D009067:Mouthwashes; D013193:Stainless Steel; D002710:Chlorhexidine