Systemic Antibiotic Therapy

Systemic antibiotics are drugs that, when given, affect the whole body. Typically administered in pill form, periodontists use systemic antibiotics to treat acute infections, such as a gum abscess (gum boil), and before treatment when patients have certain medical conditions, such as prosthetic heart valve or prosthetic joint. Systemic antibiotics are also recommended for one to two weeks after regeneration and dental implant procedures to prevent infection during critical early healing stages.

Because periodontal disease is an infection, it might seem logical that antibiotics could eliminate the problem. Unfortunately, when treating routine periodontal breakdown, the effects of antibiotics are short-lived because bacteria that cause the disease returns immediately when antibiotics are discontinued. More effective at controlling the infection, periodontal cleanings done to remove calculus and plaque appear to be as effective as antibiotics in controlling the infection.

Systemic antibiotics are not necessary or useful for most routine periodontal conditions, but in some advanced cases systemic antibiotics can help eradicate very specific harmful bacteria. In these cases, a short-term treatment of antibiotics may be useful. When traditional treatment does not produce expected results, the mouth can be cultured to determine which specific bacteria are present and which antibiotic treatment to use.

Because overuse of systemic antibiotics can cause patient sensitivity and bacterial resistance, they should be used only when specifically indicated.

Low Dose Antibiotics

Low dose antibiotics do not target bacteria directly, but instead, change how the body responds to infection.

An effect of these antibiotics is the reduction of collagenase, an enzyme the body produces to destroy gingival tissues. We all need some collagenase as older tissue is removed and replaced with new tissue. However, in cases of periodontal disease an overproduction of collagenase is common causing the body to destroy healthy gum tissue. The antibiotic doxycycline combats these enzymes, even in small doses. The advantage is a decreased chance of resistant bacterial strains forming and fewer side effects.

Two clinical studies have shown that patients who take two capsules of Periostat (20mg Doxycycline) daily can reduce clinical inflammation. There is no scientific recommendation for patients to take the product for longer than nine months, but there’s also no scientific reason not to take Periodotat indefinitely.  However, some preliminary tests have indicated that there is a positive residual effect for three months after stopping the drug, and so some practitioners recommend taking Periostat three months on, three months off. The low 20mg doses do not qualify as an antibiotic, and there is no known effect on the pocket bacteria. Periostat is most effective when used in conjunction with other therapies that address bacterial removal. Patients who do not respond well to Periostat typically exhibit inflammation despite reasonable oral hygiene.

Local Antibiotic Therapy

While systemic antibiotics have a very limited use in treating typical periodontal disease, there has been much interest in local antibiotic delivery. If an antibiotic can be delivered directly to the pocket, without the patient having to take systemic doses, there are far fewer side effects, and fewer chances of resistant bacteria forming. In addition, with direct local delivery, the concentration of the antibiotic at the diseased site can be 100 times greater than taking the medication orally. However, it is important to note that all local delivery antibiotics are recommended as adjuncts to scaling and root debridement, and not as stand-alone treatments.

Systemic antibiotics are diluted before reaching the pocket. With local application, the antibiotic is inserted directly into the pocket, resulting in much higher concentrations.


The most recent local antibiotic therapy introduced consists of small spheres of minocycline, a derivative of tetracycline. This drug, similar to the ingredients in Actisite and Atridox®, is very effective in killing the bacteria that are thought to cause periodontal disease. The primary advantage of this new product is the ease of use. The spheres, which look like a fine powder, are contained in a small blunt plastic needle, and are injected into the pocket. This requires no anesthesia. The spheres are bioadhesive, and stick to the pocket wall where they slowly release minocycline over a 14-21 day period. Because the spheres are also biodegradable they do not require removal.

Delivery syringe containing Arestin (minocycline) The plastic syringe consists of a cap,a plunger, and the Arestin, which is expelled by the plunger
Close-up of Arestin powder being
expelled from syringe tip
Arestin being expelled under the gum
and into the periodontal pocket

Generally speaking local delivery antibiotics are used in the Periodontal Maintenance phase of therapy, when isolated areas of the mouth seems to be worsening. Their use is generally not recommended during the active phase of treatment. The effectiveness of these products is somewhat controversial, and while there is usually some improvement, whether these results are long-term has yet to be demonstrated. Certain cases seems to respond better than others, and your periodontist will help advise you whether these treatments may be beneficial in your particular case.