A laboratory study of the effect of thermocycling in saline and artificial saliva on two dentine bonding agents

Thermocycling of composite resins in saline and artificial saliva was carried out in order to determine the effect of these solutions on the bonding of Lumifor/Gluma and Valux/Scotchbond to dentine and enamel. Minimal Class V cavities were prepared in extracted human teeth and restored with light-cured composite resins, following each manufacturer's instructions. The restored teeth were subjected to 500 cycles at temperatures ranging between 5 degrees C and 45 degrees C. One group was thermocycled in saline, the other in artificial saliva. The resultant marginal gaps were stained and evaluated microscopically. No difference was found between the respective composite resins. However, significantly more gaps were present in those restorations thermocycled in saline.