This study was conducted to investigate the effects of multibanded orthodontic appliances on dental caries activity. The subjects consisted of 50 males and females with multibanded orthodontic appliance and the same number of caries free group. The following conclusions were obtained, 1. There was significant difference between the experimental group and control group in the tests of Snyder colorimetric test, acid :buffering capacity and oral glucose clearance test (at 5% level of significance). 2. There was no significant difference between the experimental group and control group in the tests of unstimulated salivary flow fate, stimulated salivary flow rate and salivary viscosity test (at 5% level of significance). 3. Dental caries activity was higher in experimental group than in control group.