Local antimicrobial therapy after initial periodontal treatment - A randomized clinical trial comparing three biodegradable sustained release polymers

Aim: The aim of this single-blind, randomized, parallel-designed clinical trial (RCT) was to evaluate the clinical and microbiological effects of three sustained-release biodegradable polymers delivered into periodontal pockets following initial periodontal therapy. Methods: Forty-seven patients (28 females and 19 males) with a mean age of 51 years (range 29-71) underwent a periodontal examination at baseline (i.e. Week 0) and after 18 weeks. This included the assessment of the Plaque Index (PlI), Bleeding on Probing (BOP), Pocket Probing Depths (PPD) and Probing Attachment Levels (PAL) at six sites per tooth. Two to 4 months prior to baseline, all subjects had received initial periodontal therapy including motivation, instruction in oral hygiene practices and full-mouth scaling and root planing. At the treatment appointment (i.e. Week 2), the patients were randomly assigned to receive either Atridox(TM), Elyzol(R) Dental Gel or PerioChip(R) at all residual periodontal pockets with a probing depth greater than or equal to 5 mm and concomitant BOP. In accordance with the manufacturer's recommendations, Elyzol(R) Dental Gel was applied for a second time 7 days later. In addition to the clinical evaluation, subgingival microbiological samples were collected prior to treatment (i.e. Week 2) and at Weeks 4 and 18. Analysis of variance/covariance was used to evaluate changes from baseline to Week 18 for the clinical parameters. Results: Between the baseline and 18-week examinations, subjects treated with Atridox showed a significantly greater gain in mean PAL of 0.33 mm +/- 0.09 (SD) than subjects treated with Elyzol(R) Dental Gel [0.03 mm +/- 0.09 (SD)](p=0.03). However, the gain in PAL of 0.16 mm +/- 0.10 (SD) found after PerioChip(R) application did not differ significantly from that obtained following the application of Atridox(TM) (p=0.27). Of the sites treated with Atridox(TM) , 42% gained greater than or equal to 1 mm PAL and 9% greater than or equal to 2 mm PAL as opposed to the sites treated with Elyzol(R) Dental Gel, in which 34% gained greater than or equal to 1 mm PAL and 8% gained greater than or equal to 2 mm PAL. Of the sites treated with PerioChip(R), 36% gained greater than or equal to 1 mm and 6% gained greater than or equal to 2 mm PAL following a completed initial periodontal therapy. Conclusions: The application of the three biodegradable sustained release devices tested following initial periodontal therapy resulted in a statistically significant gain in mean PAL for Atridox(TM) and a significant reduction in PPD for all three devices during the study period. Furthermore, when sites treated with Atridox(TM) were compared with sites treated with Elyzol(R) , a significant difference in mean PAL gain (0.3 mm) was observed.