A RANDOMIZED CONTROLLED TRIAL OF A 2-PERCENT MINOCYCLINE GEL AS AN ADJUNCT TO NONSURGICAL PERIODONTAL TREATMENT, USING A DESIGN WITH MULTIPLE MATCHING CRITERIA

Topical locally delivered minocycline is an adjunctive to non-surgical periodontal treatment, but there are few reported trials. Previous tr ials have reported differences between changes in probing depth in tre atment and control groups, but no differences in probing attachment le vel. In the present study, 30 subjects were paired according to gender , age, ethnic group, smoking habits, and probing depths. Both groups r eceived intensive oral hygiene education and root planing with local a naesthesia. Active or placebo gel was placed subgingivally at planed s ites in each subject according to a double-blind protocol, immediately after instrumentation, and 2 and 4 weeks later. A periodontal examina tion was made with a constant force probe before instrumentation, and 6 and 12. weeks later. 2 subjects failed to complete the study, and th eir pairs were therefore not included in the analysis. Results were te sted with analysis of covariance. Differences between groups in mean p robing depth did not reach statistical significance at any visit (base line: test (T)=5.93 mm, control (C)=5.74 mm; 6 weeks: T=3.53 mm, C=3.6 3 mm; 12 weeks: T=3.29 mm, C=3.44 mm), but mean probing attachment lev els were different (p<0.05) at both reassessments (baseline: T=6.86 mm , C=6.83 mm; 6 weeks. T=4.93 mm, C=5.30 mm; 12 weeks T=4.91 mm, C=5.27 mm). There was also a difference in the number of sites with bleeding on deep probing at 12 weeks (p<0.05). This trial showed that adjuncti ve minocycline gel provided a more advantageous outcome for nonsurgica l periodontal treatment in terms of probing attachment level and bleed ing on deep probing. This trial was a good example of experimental, as opposed to community, design, and used limited resources to show a cl ear result.