A method for testing denture adhesives

An in vitro test is described that simulates the in vivo fate of a denture adhesive, namely destruction, dilution, and dissolution of the adhesive, by repeated measurement of tensile bond strength for the adhesive in isotonic saline over time. The bond strengths were measured under two different settings of the testing machine. The main compositions of three denture adhesive pastes, Fittydent, Fixodent, and Super Poli-Grip and one powder adhesive, Super Wernet's, were determined by infrared spectroscopy. The tensile bond strengths of these adhesives and those of pure tragacanth gum were subjected to a three-way analysis of variance. The Fittydent and Super Poli-Grip adhesives exhibited the best results over time. The most appropriate of the described methods for testing denture adhesives seem useful; however, when seen in relation to the results of a published clinical study where the patients were asked to evaluate the retention and the duration of some of these adhesives, there are indications that the clinical validity of the method might be improved if paste adhesives are tested at temperatures above 35 degrees C.