AimThe aim of this study was to evaluate the effect of saliva contamination and curing and reusing self-etching primer (SEP) on shear bond strength of orthodontic brackets. MethodsEighty sound extracted human premolars were collected and divided equally into 8 groups of 10 teeth in. Orthodontic metal brackets were bonded with self-etching primer adhesive under the following enamel surface conditions: (1) (control): SEP/XT(bonding)/Light Curing(LC), (2) SEP/LC/XT/LC (3) SEP/saliva/XT/LC, (4) SEP/saliva/LC/XT/LC, (5) SEP/saliva/SEP/XT/LC, (6) SEP/saliva/SEP/LC/XT/LC, (7) SEP/saliva/LC/SEP/XT/LC, (8) SEP/saliva/LC/SEP/LC/XT/LC. Samples were stored for 24h in distilled water at 37°C, then thermocycled for 1000 times (5–55°C). Shear bond strength of each sample was examined with a universal testing machine. The load was recorded at bond failure. Data were analyzed statistically. ResultsClinically acceptable bond strength was found for all groups. There were significant differences between groups 1 and 4, also groups 3 and 4. ConclusionsSaliva contamination has no significant effect on the shear bond strength of SEP. Light curing of SEP increased the bond strength. SEP has more value than the conventional primer in reaching to good bond strength results so that it may diminish the bad effect of saliva contamination on shear bond strength.