Clinical Efficacy of Local Delivery Minocycline Gel for the Treatment of Moderate to Severe Periodontitis

Abstract

Background: Local delivery of antimicrobial agents has been used for many years as an adjunct to treat periodontal disease. The gel form of minocycline local delivery application has an advantage in that it allows multiple sites to be treated with the same syringe loaded with minocycline gel when compared to other modalities on the market. However, the use of this gel form of minocycline has not been clinically proven effective or approved for clinical use in the United States. Objectives: The objective of this study was to determine the clinical efficacy of a 2.1% minocycline gel as an adjunct to scaling and root planning (SRP) for treating patients with moderate to severe periodontitis. The hypothesis for this study is that patients with moderate to severe periodontitis would have a statistically significant greater increase in clinical attachment (CAL) gain, reduced pocket depth (PD), and reduced bleeding on probing (BOP) when SRP with adjunctive minocycline gel were used when compared to patients treated with sham (SRP alone) and vehicle control (SRP+ vehicle without active ingredient). Material and Methods: Eligible patients (n=59) had at least ten remaining teeth and each subject had at least four teeth with pocket depths ≥5 - ≤9 mm with BOP at baseline. In addition to baseline, patients were evaluated at three, six and nine months. Enrolled subjects were randomly assigned to one of three groups: 1) root planing therapy only-sham; 2) root planing therapy and the vehicle control; 3) root planing and minocycline gel. The minocycline gel as well as the vehicle control were administered at 2 weeks and at the one, three and six-month visits. No mechanical debridement as supportive periodontal therapy was performed during this study. Results: It was found that in the overall study population the minocycline study group, when compared to the sham group, resulted in a greater significant decrease BOP (p=0.035) at 3-month, but not when compared to the vehicle control group (p=0.64). In sites presenting with the severe form of periodontitis (≥8 mm), there was a statistically significant difference between the minocycline gel group and the sham group with respect to % BOP reduction at 9-months (p=0.014). On the other hand, results failed to show any other statistically significant difference between the minocycline gel group and the sham group with respect to other clinical variables including PD and CAL (p>0.05). However, minocycline gel did present with statistically significant differences compared to the vehicle control group with respect to the clinical variables. Conclusion: The minocycline gel as an adjunct to non-surgical periodontal therapy provided a significant favorable clinical effect in decreasing BOP for all moderate to severe periodontitis sites following SRP at the 3-month evaluation. In the severe forms of periodontitis, minocycline gel had an adjunctive favorable effect at 9-months after SRP with respect to %BOP reduction. This study was supported in part by Sunstar Americas, Inc. and the clinical research center at the University of Minnesota.