The ultimate goal of periodontal therapy is the regeneration of periodontal tissue which has been lost due to destructive periodontal disease. Various periodontal procedures have been used throughout the years in an attempt to reestablish attachment of periodontal tissues to root surfaces affected by periodontitis. Flap debridement surgery has been demonstrated to be a successful procedure in gaining the probing attachment level and reducing probing depth. A tendency towards impaired wound healing following periodontal procedures in smokers has been clinically documented. But, previous clinical studies on healing response in smokers are based on a retrospective design.

The purpose of this study was to evaluate the treatment outcome following flap debridement surgery in smokers compared to nonsmokers.

25 patients with moderate to advanced periodontitis were included for study. Among these patients, 13 patients were smokers, and 12 patients were nonsmokers. Mucoperiosteal flap was raised with the sulcular incision. No antibiotic treatment was administered postsurgery. The patients was recalled at monthly intervals during a period of 6 months following the surgery. The patients were received supragingival scaling and oral hygiene reinforcement. All the recordings, including modified O'Leary plaque control record, bleeding on probing! probing pocket depth, probing attachment level, were recorded, presurgery and 6 months postsurgery.

The changes of all the recordings at 6 months after flap debridement surgery revealed the following results:

1. PI on all the dentitions and surgical sites showed no statistical significance between smokers and nonsmokers at presurgery. But, smokers demonstrated a significantly lower % of PI than nonsmokers at 6 months postsurgery.

2. Smokers demonstrated a greater % of BOP sites than nonsmokers on the surgical sites and all the dentitions, presurgery and 6 months postsurgery. But, there was no statistical significance between two groups.

3. Smokers exhibited significantly less reduction of probing depth in the 3 mm or less probing pocket depth(PPD) group, 6mm or more PPD group and total PPD group when compared to nonsmokers at 6 months postsurgery.

4. Smokers exhibited significantly less gain of probing attachment level(PAL) in the 3mm or less PPD group, 6 mm or more PPD group and total PPD group when compared to nonstmokers at 6 months postsurgery.