Resumen de Clinical and Microbiologic Effects of Adjunctive Metronidazole Plus Amoxicillin in the Treatment of Generalized Chronic Periodontitis: Smokers Versus Non-Smokers
Background: The aim of the present study is to evaluate the clinical and microbiologic effects of the adjunctive use of metronidazole (MTZ) and amoxicillin (AMX) in the treatment of smokers and non-smokers with generalized chronic periodontitis (CP).
Methods: Thirty-two smokers and 32 non-smokers were selected and received scaling and root planing (SRP) combined with MTZ (400 mg three times daily) and AMX (500 mg three times daily) for 14 days. Clinical and microbiologic examinations were performed at baseline and 3 months after SRP. Nine subgingival plaque samples per patient were analyzed using checkerboard DNA�DNA hybridization.
Results: Both groups presented a significant improvement in all clinical parameters at 3 months after therapy (P <0.05). Non-smokers showed lower mean number of sites with probing depth (PD) =5 mm after therapy. Fewer non-smokers exhibited at least nine of these sites at 3 months after treatment. Non-smokers also presented the greatest reductions in mean PD and gain in clinical attachment between baseline and 3 months after therapy at initially deep (PD =7 mm) sites (P <0.01). The most beneficial changes in the microbial profile were also observed in the non-smoker group, which showed the lowest proportions of the orange complex at 3 months, as well as a significant increase in the proportions of Actinomyces species after treatment.
Conclusion: Smokers with CP benefit less than non-smokers from treatment by the combination of SRP, MTZ, and AMX.
Smoking plays a significant role in the pathogenesis of chronic periodontitis (CP),1-4 and it is one of the main and most prevalent risk factors of this infection.3,5 Positive associations between dose and years of exposure to tobacco products and the severity of periodontal disease have been reported,6,7 with odds ratios varying from 2 to 8, depending on the definition of periodontal disease and smoking history.3,5,8 The negative effects of smoking on bacterial challenge9-13 and the reduced immune-inflammatory response14-17 have been suggested as possible mechanisms by which smokers are at increased risk of periodontitis.
Several studies have reported greater reduction in probing depth (PD) and gain in clinical attachment level (CAL) in non-smokers compared with smokers after different periodontal therapies, including non-surgical18-22 and surgical approaches.23,24 Jin et al.21 reported a statistically significant greater mean PD reduction in non-smokers (2.4 ± 0.2 mm) compared with smokers (1.1 ± 0.3 mm) at 3 months after scaling and root planing (SRP). In addition, a systematic review evaluating the effect of smoking on non-surgical periodontal therapy25 demonstrated that the mean difference in PD reduction between smokers and non-smokers in sites with initial PD =5 mm were 0.43 mm in favor of non-smokers. Hence, smokers seem to respond less favorably to periodontal therapy, suggesting that these patients might need additional treatments to achieve better and more sustained clinical outcomes.
Randomized controlled clinical trials have demonstrated that the use of amoxicillin (AMX) and metronidazole (MTZ) as adjuncts to mechanical therapy improves the clinical and microbiologic outcomes of SRP in non-smokers with CP.26-30 Certain clinical and microbiologic benefits of SRP + MTZ + AMX in smokers have been described recently by the present authors,31 and apparently this therapy was less effective in reducing certain putative pathogens from the orange complex compared with a group of non-smokers.29 However, to date, the effects of this antibiotic protocol have not been directly compared in non-smokers and smokers. Therefore, the aim of this study is to compare the clinical and microbiologic effects of the adjunctive use of MTZ + AMX to SRP in smoker and non-smoker patients with generalized CP. It was hypothesized that non-smokers would reap greater benefit from this combination of therapies than the smokers.
