A randomized four-years study of periodontal therapy.

The purpose of this study was to compare the long term effectiveness of scaling and root planing alone to scaling and root planing followed by periodontal surgery. Seventeen subjects with moderate to advanced periodontitis received through scaling and root planing as well as oral hygiene instruction. A modified Widman flap was then randomly performed for one-half of each subject's dentition. Recall prophylaxis and oral hygiene reinforcement were administered for 4 years after completion of therapy. Shallow crevices (1--3 mm)subjected to either procedure tended to increase slightly in depth and exhibit a slight loss of attachment when compared to pretreatment measurements. Moderately deep pockets (4--6 mm) treated by either procedure were reduced and demonstrated a sustained gain or maintenance of attachment level. Pockets initially greater than or equal to 7 mm exhibited the greatest reduction in depth and attachment gain. Gingivitis was reduced following either procedure for moderate and deep pockets. No difference in supragingival plaque retention was noted and both procedures reduced calculus. The results indicate that both procedures were effective in treating moderate to advanced periodontitis. However, the additional flap procedure tended to result in greater pocket reduction and attachment gain for deeper pockets.