Arestin - Perio's Newest Tool

In mid June 2001, I had the opportunity to meet in Dallas with the lead researcher for Arestin, some marketing representatives from Orapharma, Inc., and several periodontists to discuss their product. They were looking for feedback as to our views on the efficacy of Arestin and their marketing efforts. Arestin was approved by The FDA as an adjunctive treatment (with root planing) for periodontitis. New innovations are exciting, especially if they perform in a manner consistent with all the hype. Their product is generating a lot of interest. I have received many calls from dental colleagues asking what I thought of the Arestin. Here is a "bottom line" synopsis.

Local Drug Delivery for the treatment of periodontitis is not a new concept. Studies involving tetracycline in ethylene vinyl acetate fibers (Actisite) began in the 1980's. They were followed in 1998 chlorhexidine chips (PerioChip) and again in 1999 by doxycycline in a polylactic acid gel (Atridox). Therefore, Arestin represents a third generation product with significant enhancements over its' predecessors.

Arestin is minocycline in a PGLA polymer. The product is formulated into syringeable microspheres. No mixing is needed. When Arestin is introduced into a pocket, it quickly lines the wall of pocket epithelium and the root of the tooth. The antibiotic is gradually released as the PGLA is slowly dissolved by hydrolysis. Each unit dose contains exactly

1 mg of minocycline, so there is no doubt as to the actual amount administered to each site. A single dose can treat one pocket. Arestin maintains minimal inhibitory concentrations for P. gingivalis, P. intermedia, and A. actinomycetumcomitans (3 notable pathogens) for at least 14 days. A single dose costs a little over $12.00, however the company does offer promotional and volume purchase discounts. Lets get to the science and look at how it performs with comparisons to the predecessors.

Two multi center clinical trials were performed to get the product approved by FDA. The basic protocol had sites with 5 mm or more pocket depths. There were 3 groups: Control-scaling and root planing alone (C), scaling and root planing with vehicle only, and scaling and root planing with Arestin (T). I will report only the control (C) and test (T). The study lasted nine months. Arestin was administered 3 times: at baseline, at 3 months and at 6 months. To compare with other products, I have included studies on Actisite, PerioChip, Atridox, and Arestin.

Legend: #Aps is the number of times the test product was administered to a site, Dur is the duration of study in months, C and T are the values for the magnitude of the pocket depth reduction in mm's from the baseline to the end of study for the C and T groups, respectively and Diff is the difference in the two groups in mm's.

References: AC- Drisko. J Perio 1995;66:692, PC- Jeffcoat. J. Perio 1998;69:989, AT- Garret. 1999;70:490, and AR- unpublished (taken from prescribing info. Accepted for publication in J Perio). These references are representative examples taken from AAP Position Paper- The Role of Controlled Drug Delivery in Periodontitis. J Perio 2000;71:125

As you can see, all of the products generate some benefit over scaling and root planing alone. Arestin with root planing (T) resulted in probing depth improvements that were greater than the root planing only group (C). The reduction difference of 0.24 mm compares favorably with the other products. Arestin also performs quite well in furcations with a 0.30 mm improvement difference between T and C groups. Gains were also seen in smokers. The test group showed 0.28 mm more pocket depth reduction than the control group. This is a benefit since these etiologic factors often lead to refractory sites. Most studies of other systems did not report these sub groups.

My Interpretation:

Arestin represents a significant improvement in the delivery technology for controlled release local drug applications in periodontal lesions. I have found that the product is by far the easiest to use, the most comfortable to receive from a patient's point of view, and seems to have the longest duration of activity. These are things to be excited about. My experience with representatives of Orapharma was positive in that they are trying to get their marketing efforts to match what their supporting studies demonstrated. They were clearly trying not to package Arestin as a cure all for periodontitis.

I see Arestin as a potential adjunct in the supportive periodontal therapy (recall) arena in our office. The numbers of furcations, teeth with root flutes, and teeth with crowding or atypical emergence profiles are at times, hard to maintain. Refractory sites often need additional steps. Arestin may play a significant role in those situations. Peri implantitis sites may also improve with this therapy. In some limited situations, I may use it during initial therapy when a site may not be a candidate for surgery and when conventional debridement will not control the infection.

In my opinion, you will not see periodontists applying any controlled release product routinely into every pocket over 4 mm in our scaling and root planing patients. The cost to benefit analysis simply is not favorable enough to warrant that approach. In the past, some product representatives have attempted to convince providers that controlled release products should be used in all root planing cases. Periodontics, as a specialty, is very concerned about the widespread overuse of antibiotics in dentistry to control periodontitis. Judicious antibiotic use is always indicated.

To sum up, each clinician has to gauge the severity of a particular periodontitis site and recommend therapy appropriate for that site. No single therapy is appropriate for all sites. With experience, you will find Arestin useful in sites appropriate for controlled release drug therapy.

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