Study shows SRP is significantly more effective with local antibiotics

Sept. 28, 2007
Arestin plus SRP therapy creates environment conducive to healing, reducing pocket depth by decreasing perio pathogens and increasing attachment level with almost twice the effect on bleeding.

A new study published this month in the Journal of Periodontology shows that a combination of Arestin® (minocycline hydrochloride) Microspheres 1 mg, plus scaling and root planing (SRP) is significantly more effective than SRP alone in controlling periodontal disease. Study results indicate clearly that when Arestin is placed at the time of initial SRP, clinical markers of disease are reduced, such as pocket depth, inflammation, and bleeding on probing, thus creating an environment where healing has occurred.

The study measured the antimicrobial effectiveness of using Arestin to treat periodontal pathogens, also called red complex bacteria (RCB) (Porphyromonas gingivalis, Tannerella forsynthensis, and Treponema denticola), that play a primary role in periodontal infection. When administered in conjunction with SRP, Arestin significantly reduced the proportion of these disease-causing bacteria by 29 percent more than SRP alone and showed nearly twice the reduction in levels of these periodontal pathogens. Additionally, Arestin patients maintained relative levels of periodontal pathogens normally seen in healthy patients, while the SRP only patients did not.

Arestin plus SRP also significantly decreased pocket bleeding by 79 percent, more than SRP alone. From a microbiologic standpoint, reduction in pocket bleeding is a measure of reduced inflammation and reduced nutrient flow. This restriction of nutrients makes the environment less favorable for the re-growth of these periodontal pathogens.

Additionally, the study found that the combination of Arestin and SRP led to positive changes in clinical attachment level (CAL) and overall reduction of periodontal disease. The mean gain in CAL for subjects receiving both treatments was 45 percent greater than in those treated with PDR alone (1.16 mm as opposed to 0.80 mm, respectively). Regarding pocket depth reduction (PDR), subjects treated with Arestin and SRP experienced average reductions that were 37 percent greater than those observed in SRP-only groups (1.38 mm vs 1.01 mm, respectively). These findings suggest that the combination of Arestin and SRP is more effective in targeting bacteria that grow to a greater density in deeper pockets, such as the red complex strain, than SRP alone.

Study authors were excited to find that the anti-microbial effect of locally delivered Arestin were directed primarily at the periodontal pathogens and caused little impact on healthy or normally occurring oral bacteria.

"It is now recognized that chronic periodontitis is an infectious disease in which red complex bacteria play a primary role," said Dr. J. Max Goodson, lead investigator for the study and senior member of the Department of Periodontology at the Forsyth Institute. "This study supports a very strong association between these periodontal pathogens and periodontal disease and demonstrates that local antimicrobial therapy using Arestin and SRP effectively reduces the numbers of these periodontal pathogens and their proportions to a far greater extent than SRP alone. The result of this reduction allows for improved clinical outcomes for patients treated with Arestin plus SRP."

Dr. Goodson added, "Study authors concluded locally delivered Arestin exhibited surprising specificity of action in being directed almost entirely toward inhibition of bacteria generally considered periodontal pathogens with little inhibitory effect on other species. Based on risk/benefit analysis it would seem that regular use of Arestin would be preferred because there is little or no risk, and it provides a clear benefit."

About the study

The study, titled "Minocycline HCI Microspheres reduce red-complex bacteria in periodontal disease therapy," is a phase IV, multi-center, single-blind, randomized, parallel-group trial. DNA probe analysis for 40 bacteria was used to evaluate 127 patients with moderate-to-advanced chronic periodontitis.

The study's authors include: J. Max Goodson, (Forsyth Institute); John C. Gunsolley (Virginia Commonwealth University); Sara G. Grossi (East Carolina University); Paul S. Bland (University of Tennessee); Joan Otomo-Corgel (University of California-Los Angeles School of Dentistry); and Fergus Doherty (University Medical School, Queens Medical Centre, Nottingham, UK); and J. Comiskey (OraPharma, Inc). The study was supported in part by a grant from OraPharma, Inc.