Antimicrobial and physical characteristics of orthodontic primers containing antimicrobial agents.
OBJECTIVE
To compare the antimicrobial and physical properties of experimental primers containing chlorhexidine (CHX) or ursolic acid (UA) with a commercial primer.


METHODS
Two antibacterial agents, 3 mg each of CHX and UA were incorporated respectively into 1 ml of Transbond XT primer (TX) to form antibacterial primers, TX-CHX and TX-UA. The antimicrobial activity of the three primers (TX, TX-CHX, and TX-UA) against Streptococcus mutans in both planktonic and biofilm phases was analyzed by determining minimum inhibitory and bactericidal concentrations and by performing growth and biofilm assays. Growth and biofilm assays were performed in both the absence and presence of thermocycling in a water tank to analyze the effects of water aging on the antimicrobial activities of primers. After bonding brackets onto bovine incisors using the primers, shear bond strength and mode of fracture were analyzed to compare physical properties.


RESULTS
TX-CHX had stronger antimicrobial activity against S. mutans in the planktonic and biofilm phases than did TX or TX-UA. When applied, TX-CHX completely inhibited the growth and biofilm formation of S. mutans . In addition, the antimicrobial activity of TX-CHX was maintained after thermocycling. However, TX-UA did not show significant antimicrobial activity compared with TX. There was no significant difference in either shear bond strength or bond failure interface among the primers.


CONCLUSIONS
Incorporation of CHX into an orthodontic primer may help prevent enamel demineralization around surfaces without compromising its physical properties.
Shin-Hye
SH
Chung
Soha
S
Cho
Kyungsun
K
Kim
Bum-Soon
BS
Lim
Sug-Joon
SJ
Ahn
D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D018441:Biofilms / Q000254:growth & development*; D002417:Cattle; D002710:Chlorhexidine / Q000494:pharmacology*; D001840:Dental Bonding; D066298:In Vitro Techniques; D008826:Microbial Sensitivity Tests; D016910:Orthodontic Brackets; D019279:Resin Cements / Q000494:pharmacology*; D013295:Streptococcus mutans / Q000187:drug effects*; D013499:Surface Properties; D017001:Tooth Demineralization / Q000517:prevention & control*; D014315:Triterpenes / Q000494:pharmacology*; D000097245:Ursolic Acid
D000890:Anti-Infective Agents; D002710:Chlorhexidine; D019279:Resin Cements; D014315:Triterpenes; D000097245:Ursolic Acid; C477790:Transbond XT
Antimicrobial; Bond strength; Bonding; Orthodontic primer