Comparison of clinical outcomes following treatment of chronic adult periodontitis with subgingival scaling or subgingival scaling plus metronidazolegel

Background, aims: Conventional treatment of chronic periodontitis involves mechanical debridement of periodontal pockets. Recently, subgingival antimi crobials have been used adjunctively following such debridement. This 2-cen tre study compared the clinical effects of subgingival scaling (SRP) with S RP plus subgingival application of 25% metronidazole gel, Elyzol(R) (SRP+ge l), in patients with chronic adult periodontitis. Method: Voluntary informed written consent was obtained from 45 subjects at the Eastman (mean age 46, range 34-63) and 43 subjects at RAF Halton (mean age 47, range 34-71) who participated in this blind, randomised split-mout h design study. All had at least 2 sites in each quadrant with probing pock et depth (PPD) greater than or equal to5 mm. PPD bleeding on probing (BOP), and clinical probing attachment levels (CAL) measured using a stent, were recorded at baseline and at 1, 3, 6 and 9 months posttherapy. After subging ival scaling of all quadrants, 2 quadrants were randomly selected to be tre ated with metronidazole gel. Results: A paired t-test on baseline values showed no bias between groups. Both treatments effectively reduced the signs of periodontitis. At each fol low-up visit, reduction in PPD, CAL and BOP after the combined treatment wa s greater than for SRP alone. Paired t-tests showed that the improvement in the SRP+gel group was statistically significantly better (p<0.001) than fo r SRP alone (mean 0.5+/-0.6 mm. 95% CI0.4-0.6 mm.) Similarly, the % of site s which improved to a final pocket depth of 43 mm and the % of sites which improved over the 9 months of the study by as much as <greater than or equa l to>2 mm were greater for SRP+gel than for SRP alone. Conclusions: At the end of the study, the mean reductions for PPD were 1.0 mm (SRP) compared to 1.5 mm (SRP+gel), and for CAL they were 0.4 mm (SRP) c ompared to 0.8 mm (SRP+gel), with mean difference for CAL between treatment s of 0.4+/-0.6 mm (95% confidence intervals of 0.3-0.6 mm). The combination therapy of SRP+gel was superior to the conventional treatment of SRP alone , and these differences were maintained for 9 months.