RESUMO
OBJECTIVE: To compare the evaporation of vehicles included in different single-bottle adhesives as a function of time. METHODS: The following adhesives were used: Prime and Bond 2.1 (Dentsply); Single Bond (3M); PrimaBond 97' (BJM); Syntac Sprint (Vivadent); Optibond Solo (Kerr) and Syntac Single Component (Vivadent). Two primers that are used in multiple-component adhesives (PermaQuick Primer, Ultradent and Scotchbond Multipurpose Primer, 3M) as well as distilled water, 96% ethanol and acetone were also included in the experiment. Samples of these products were stored in small glass containers under controlled temperature and humidity conditions. Initials mass and mass after different periods of time were registered to calculate the percentage loss of mass. RESULTS: The analysis of variance of the results followed by orthogonal contrast comparisons revealed a significantly higher loss of mass in the single-bottle adhesives that contain organic vehicles (especially in those in which the vehicle was acetone). A somewhat lower loss of mass was found in a water-based product. CONCLUSION: There is a relationship among the evaporation possibilities of the vehicles used in single-bottle adhesive systems and their loss of mass during storage.