Objective: The outcome of non-surgical periodontal therapy is known to be inferior in smokers compared to non-smokers. In the present study, the question was asked whether such a difference in healing response may be less evident following adjunctive use of locally delivered controlled-release doxycycline.
Methods: One hundred and three patients (42 smokers, 61 non-smokers), each having at least eight periodontal sites with PPD (probing pocket depth) > or =5 mm, were following stratification for smoking randomly assigned to two different treatment protocols; non-surgical scaling/root planing (Control) or ultrasonic instrumentation+application of a 8.5% w/w doxycycline gel (Atridox trade mark ) (Test). Instructions in oral hygiene were given to all patients. Clinical examinations of plaque, PPD, clinical attachment level (CAL) and bleeding following pocket probing were performed at baseline and after 3 months. Primary efficacy endpoints were changes in PPD and CAL. Patient mean values were calculated as basis for statistical analysis (multiple regression analyses).
Results: The baseline examination revealed no significant difference in mean PPD between treatment groups or between smokers and non-smokers (mean PPD 5.7-5.9 mm). The mean PPD reduction in the control group at 3-month was 1.1 mm (SD=0.45) for smokers and 1.5 mm (0.67) for non-smokers. In the test group the PPD reduction was 1.4 mm (0.60) and 1.6 mm (0.45) for smokers and non-smokers, respectively. The mean CAL gain for smokers and non-smokers amounted to 0.5 mm (0.56) and 0.8 mm (0.71), respectively, in the control group, and to 0.8 mm (0.72) and 0.9 mm (0.82), respectively, in the test group. Multiple regression analysis revealed that smoking and initial PPD negatively influenced the treatment outcome in terms of PPD reduction and CAL gain, while the use of doxycycline had a significant positive effect.
Conclusion: Locally applied controlled-release doxycycline gel may partly counteract the negative effect of smoking on periodontal healing following non-surgical therapy.