Evaluation of the band strength and of the antimicrobial activity of different bracket bonding systems associated with chlorhexidina and fluor / Avaliação da resistência adesiva e da atividade antimicrobiana de diferentes sistemas de colagem de bráquetes associados à clorexidina e ao flúor.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

The objective of this in vitro study was to evaluate the influence of the incorporation of fluor and chlorhexidine in the bond strength and in the antimicrobial activity of different bracket bonding systems (Transbond XT System / 3M-Unitek and Enlight System / Ormco) whose respective adhesives were pre-mixed with fluoride varnish (Fluor Protector / Ivoclar-Vivadent) and/or chlorhexidine varnish (Cervitec / Ivoclar- Vivadent). The sample used consisted of human pre-molars extracted for orthodontic purposes and divided in eight experimental groups: G1 Transbond XT System according to the manufacturers instructions; G2 - Transbond XT System combined with chlorhexidine varnish; G3 Tansbond XT System combined with fluoride varnish; G4 - Transbond XT System combined, simultaneously, with fluoride and chlorhexidine varnishes; G5 Enlight System according to the manufacturers instructions; G6 Enlight System combined with chlorhexidine varnish; G7 Enlight System combined with fluoride varnish; G8 Enlight System combined, simultaneously, with fluoride and chlorhexidine varnishes. The bond strength evaluation was obtained through the shear bond strength test, and the adhesive remnant index (ARI) on the tooths enamel surface was also tested after bracket debonding. Moreover, the samples were submitted to ph cycling, simulating a cariogenic challenge, and also Staphylococcus aureus cultures, to evaluate the possibility of these bonding systems, associated with fluoride and/or chlorhexidine, to provide protection against tooths enamel demineralization and/or hinder bacterium growth, especially in areas located around the brackets. The results concluded that the bond strength was not statistically significantly altered in the experimental groups that used Transbond XT System (G2, G3 and G4), as well as in the group that used Enlight System combined with chlorhexidine varnish (G6); however in the groups that used Enlight System associated only with fluoride varnish (G7) and/or simultaneously with chlorhexidine varnish (G8) the bond strength was statistically significantly reduced when compared to the respective control group (G5). The adhesive remnant index (ARI) analysis demonstrated a predominance of score 3 in all experimental groups that used Transbond XT System and score 2 for all experimental groups that used Enlight System, and, therefore, adhesive fractures in all adhesive-bracket interfaces and mixed fractures (adhesive and cohesive), respectively. Beyond this, by observing the formation of halos of bacterium growth inhibition in the cultures, 24 hours after sample inclusion, it was evident that adhesive systems associated solely with chlorhexidine varnish (G2 and G6) were the only ones to demonstrate statistically significant antimicrobial activity. None of the experimental groups was efficient to prevent the tooths enamel demineralization after the cariogenic challenge through ph cycling.

ASSUNTO(S)

ortodontia clorexidina shear bond strength bráquetes ortodonticos chlorhexidine orthodontic brackets resistência ao cisalhamento

ACESSO AO ARTIGO

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