Antimicrobial properties of an orthodontic adhesive combined with cetylpyridinium chloride.
BACKGROUND
Patients undergoing fixed appliance treatment are at greater risk for increases in salivary and plaque levels of Streptococcus mutans and an elevated risk of dental caries. Cetylpyridinium chloride (CPC) is known to be an effective antiplaque agent. The purpose of this study was to investigate whether incorporating CPC into a commercially available orthodontic adhesive would impart antimicrobial properties without altering the diametral tensile strength of the material.


METHODS
CPC was added to a commercially available, filled, photo-activated bracket adhesive (Transbond XT, Unitek 3M, Monrovia, Calif) in varying amounts, to obtain specimens with CPC concentrations of 0% (control), 2.5%, 5.0%, and 10.0% by weight. Adhesive discs 2 mm thick and 4 mm in diameter were incubated with Streptococcus mutans for 48 hours. The diameters of the zones of bacterial inhibition were measured in an agar disc diffusion assay; specimens of each concentration were tested every other week for 196 days. Other discs were soaked in distilled water for 180 days. The amount of CPC released into the water from the modified discs was measured and recorded on days 7, 15, 30, 60, and 180 by using a spectrophotometer at 254 nm. Diametral tensile strength of the modified adhesive discs was measured with a universal testing machine, and the effect of water aging was also evaluated.


RESULTS
The measured zone of bacterial inhibition increased as CPC content increased. All CPC-adhesive specimens maintained antimicrobial activity up to 196 days. No zone of bacterial inhibition was measured around the control specimens. CPC release was observed through the end of 180-day period, but the greatest release was recorded in the first week. There was no significant difference (P < .05) in diametral tensile strength between the 2.5% CPC-adhesive group and the control; there were significant differences among the 5.0% and 10.0% CPC-adhesive groups and the control. Water aging had no significant effect on diametral tensile strength other than decreasing it for the test group containing 10.0% CPC.


CONCLUSIONS
The incorporation of 2.5% CPC in adhesive material imparted antimicrobial activity without altering diametral tensile strength.
Department of Orthodontics, College of Dentistry, University of Illinois, Chicago, IL 60612-7211, USA.
Tahani A
TA
Al-Musallam
Carla A
CA
Evans
James L
JL
Drummond
Claude
C
Matasa
Christine D
CD
Wu
D000269:Adhesives / Q000737:chemistry*; D000704:Analysis of Variance; D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D002594:Cetylpyridinium / Q000494:pharmacology*; D001840:Dental Bonding; D003799:Dental Stress Analysis; D008422:Materials Testing; D016910:Orthodontic Brackets / Q000009:adverse effects; D019279:Resin Cements / Q000737:chemistry*; D013295:Streptococcus mutans / Q000187:drug effects*; D013718:Tensile Strength; D013997:Time Factors; D017001:Tooth Demineralization / Q000209:etiology / Q000517:prevention & control; D017155:Wettability
D000269:Adhesives; D000891:Anti-Infective Agents, Local; D019279:Resin Cements; C477790:Transbond XT; D002594:Cetylpyridinium