Laboratory evaluation of a new denture adhesive

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 °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 (α=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. Significance. The generally favorable laboratory performance of Comfort-DA formulations indicates that this product may be an efficacious denture adhesive.