title: Laboratory evaluation of a new denture adhesive.
abstract: OBJECTIVE
  The ideal denture adhesive demonstrates a neutral or slightly basic pH, satisfactory bonding load, and minimal toxicity to the oral mucosa. The purpose of this study was to evaluate the properties of a new denture adhesive (Comfort-DA, developed by the authors).
  
  
  METHODS
  Comfort-DA was evaluated in the laboratory to determine the clinical effect of pH, bonding strength, and cytotoxicity. Firstly, the material was diluted at 1.0, 2.0, 3.3, 5.0, and 10% concentrations. Then the pH values were measured at 1-, 2-, 3-, 4-, 5-, 6-, and 8-hour intervals. Secondly, bonding load test was performed between acrylic resin samples on a universal testing machine. An existing product, Fittydent, was used as a control. Finally, the cytotoxicity of several dilutions of Comfort-DA was recorded with a MTT assay on human oral fibroblast cells. Cell viability was recorded by optical density after culturing in an atmosphere of 5% CO2 and 95% air at 37 degrees C for 2, 3 and 4 days, respectively. Wells containing fresh medium alone served as controls. All the results were compared with ANOVA or Tukey intervals (alpha = 0.05).
  
  
  RESULTS
  Comfort-DA remained above the critical pH for hydroxyapatite (pH 6.5) in all dilutions throughout the study. Results of bonding strength test indicated that Comfort-DA was significantly stronger than Fittydent (p < 0.05). The statistical analysis of results for cytotoxicity showed that Comfort-DA only displayed slight cytotoxicity.
  
  
  CONCLUSIONS
  The generally favorable laboratory performance of Comfort-DA formulations indicates that this product may be an efficacious denture adhesive.
authors.affiliation: Department of Prosthodontics, College of Stomatology, Sun Yat-sen University, No. 56 of Lingyuan road West, Guangzhou, Guangdong 510055, China. zhaokirk@163.com
authors.forename: Ke
authors.initials: K
authors.lastname: Zhao
authors.forename: Xiang-Rong
authors.initials: XR
authors.lastname: Cheng
authors.forename: Yong-Lie
authors.initials: YL
authors.lastname: Chao
authors.forename: Zhi-An
authors.initials: ZA
authors.lastname: Li
authors.forename: Guang-Li
authors.initials: GL
authors.lastname: Han
mesh_terms: D000268:Adhesiveness; D000269:Adhesives / Q000633:toxicity; D000704:Analysis of Variance; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003781:Denture Retention; D005347:Fibroblasts / Q000187:drug effects; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing
chemical_list: D000269:Adhesives