title: Antibacterial properties of 4 orthodontic cements.
abstract: BACKGROUND
  White spot lesions are observed in nearly 50% of patients undergoing orthodontic treatment. Long-lasting antibacterial properties of orthodontic cements can reduce this phenomenon.
  
  
  METHODS
  The antibacterial properties of 4 orthodontic cements were evaluated by direct contact test (DCT) and agar diffusion test (ADT). With the DCT technique, octet specimens of glass ionomer (CX-Plus; Shofu, Kyoto, Japan), reinforced glass ionomer (GC Fuji ORTHO LC; GC Corporation, Tokyo, Japan), and 2 composite (Transbond XT and Transbond Plus; 3M Unitek, Monrovia, Calif) orthodontic cements were placed on the sidewalls of wells of a 96-microtiter plate. Streptococcus mutans cells (ca. 1 x 10(6) ) were placed on the surface of each specimen for 1 hour at 37 degrees C. Then, fresh media was added to each well, and bacterial growth was monitored for 16 hours with a temperature-controlled spectrophotometer. This was repeated on specimens aged in phosphate-buffered saline for 1 day, 1 week, and 1 month. The ADT was performed by placing specimens in wells punched in agar plates.
  
  
  RESULTS
  Measurement of the halo in bacterial lawn after 48 hours showed that only the glass ionomer cement (CX-Plus) produced an inhibition zone (1.2 mm around the sample). Results at the DCT showed that only the reinforced glass ionomer cement (GC Fuji ORTHO LC) exhibited potent antibacterial activity, which lasted 1 week and diminished over the next 3 weeks.
  
  
  CONCLUSIONS
  The reinforced glass ionomer cement possessed the most potent and long-lasting antibacterial activity.
authors.affiliation: Department of Restorative Dentistry, Maurice and Gabriella Goldschleger School of Dental Medicine, Tel-Aviv University, Tel-Aviv, Israel. matalons@post.tau.ac.il <matalons@post.tau.ac.il>
authors.forename: Shlomo
authors.initials: S
authors.lastname: Matalon
authors.forename: Hagay
authors.initials: H
authors.lastname: Slutzky
authors.forename: Erwin I
authors.initials: EI
authors.lastname: Weiss
mesh_terms: D000180:Acrylic Resins / Q000494:pharmacology*; D000538:Aluminum Silicates / Q000494:pharmacology*; D000704:Analysis of Variance; D000890:Anti-Infective Agents / Q000494:pharmacology*; D015169:Colony Count, Microbial / Q000379:methods; D005899:Glass Ionomer Cements / Q000493:pharmacokinetics / Q000494:pharmacology*; D009967:Orthodontic Appliances; D012044:Regression Analysis; D019279:Resin Cements / Q000494:pharmacology; D013295:Streptococcus mutans / Q000187:drug effects*
chemical_list: D000180:Acrylic Resins; D000538:Aluminum Silicates; D000890:Anti-Infective Agents; C496048:CX-Plus; C095451:Fuji Ortho LC; D005899:Glass Ionomer Cements; D019279:Resin Cements; C429625:Transbond Plus Self-Etching Primer; C477790:Transbond XT