 Test and control groups were administered either diclofenac potassium 50 mg or placebo gel caps containing inactive filler of starch flour and carboxymethylcellulose, respectively, b.i.d. after a meal for 6 months in a cyclic regimen. Administration of diclofenac potassium or placebo was undertaken from baseline to 2 months, no drug diclofenac potassium or placebo was administered from 2 to 4 months, then diclofenac potassium or placebo therapy was reinstituted b.i.d. from 4 to 6 months. To promote compliance, each patient was recalled monthly. Patients in both groups were instructed on oral hygiene, including tooth brushing for at least 2 minutes b.i.d. and daily interdental cleaning. SRP was not carried out during these recalls. During the screening period baseline as well as 2, 4 and 6 months, all subjects underwent physical examinations and biochemical analyses blood chemistry, complete blood count, urinalyses and pregnancy testing. 