Influence of smoking on periodontal healing one year after active treatment

To investigate the impact of smoking on the reduction of pockets >4 mm deep and a composite variable of residual pockets >4 mm and bleeding on probing (BoP) after treatment.

Eligible after exclusion due to missing records were 3,535 individuals, referred for periodontal treatment between 1980 and 2015. The number of teeth (NT), probing pocket depth (PPD), proportion of plaque (PLI) and BoP were registered before treatment and 1 year after treatment. To analyse the impact of smoking on PPD reduction, a mixed model adjusted for age, sex, type of therapy, baseline PPD, reduction of PLI, BoP and NT was used. Depending on residual PPD and BoP, two categories were created: good and poor responders.

PLI was reduced by 20% in non-smokers and by 18% in smokers, and BoP by 46% and 37%, respectively. In the adjusted mixed model, the mean reduction of PPD > 4 mm among smokers undergoing surgery was 14.4 versus 9.7 in non-smokers (p < .001). The odds ratio for being a poor responder was 2.40 (95% CI 1.99-2.91, p < .001) for smokers.

Although surgical treatment reduced PPD >4 mm in smokers more effectively than in non-smokers, significantly more non-smokers were good responders after periodontal therapy.