When we have a patient with clinical inflammation about many teeth and a positive BANA test in 3 or 4 plaque samples taken from about teeth with obvious inflammation, then we are able to diagnose an anaerobic infection. This suggests that an antimicrobial agent such as metronidazole, which specifically kills anaerobic bacteria, would be of value in periodontal disease. This means that those germs in the plaque which are not anaerobes will not be affected by the metronidazole and will persist in the plaque. These other germs would be facultative bacteria of the type that seem to dominate in plaque when there is periodontal health. Thus, the metronidazole would selectively kill only those bacteria that seem to be involved with the periodontal inflammation.

This assumes that there are no medical contra-indications to using metronidazole, such as allergies and drug interactions. It is important to realize that the use of alcohol while taking metronidazole can cause some patients to experience acute nausea. We normally prescribe metronidazole 500 mg twice a day (1,000 mg) for one or two weeks, depending on the severity of the periodontal condition. The dosage would be reduced or increased depending on the patient's weight, i.e., we would reduce the dosage to 750 mg for people weighing under 100 pounds, and increase it for those individuals over 200 pounds.

For patients not able to abstain from alcohol, doxycycline may be substituted for metronidazole. Doxycycline (100 mg per day) has the advantage of needing to be taken only once a day, which greatly improves patient compliance. Doxycycline may cause the emergence of antibiotic resistant organisms, and may cause a transient diarrhea, problems that are rarely seen with metronidazole. Metronidazole would be the preferred agent because it selectively kills the anaerobic gram negative members of the plaque flora, and leaves behind the facultative flora which has been shown in many studies to be associated with periodontal health. Thus, when metronidazole is stopped, the remaining germs consists of those very types that are considered to be members of the "normal flora."

 

 

Combination Therapy (Patients have a Choice)

Systemic antimicrobials such as metronidazole or doxycycline should never be used without first cleaning the teeth of bacterial accumulations (debridement procedures). This is because the numbers of bacteria in a single periodontal pocket can be as high as 500,000,000. It would be difficult to deliver enough antimicrobial agent via a pill or tablet that is swallowed (systemic route), and expect that enough of the agent would enter the pocket via the gingival crevicular fluid so as to kill this large number of bacteria. Debridement becomes essential, as a skilled clinician, by scaling and root planing can probably reduce the level of the flora by 99%, leaving behind 5,000,000 bacteria. While this is still a large number, it is within the killing range of a systemically-delivered antimicrobial agent. Thus Combination Therapy is the preferred approach to the treatment of advanced forms of periodontal disease.

The effectiveness of combination therapy is demonstrated in the before and after clinical photos below. In the before photo, the periodontal probe is inserted into the pocket to a depth of about 6 mm. Under the nonspecific plaque hypothesis, this patient would be a candidate for access surgery. However, when the teeth were cleaned by scaling and root planing combined with metronidazole antibiotic treatment, the inflamed gum tissue shrank and the tissue receded. The "after treatment photo" shows that the deep pocket from the "before treatment photo" has shrunk and the periodontal probe is now above the gums. The reduction in pockets that was obtained by treating the infection is comparable to that which would have occurred if the patient's inflamed gum tissue had been removed by a surgical procedure.

 

 

*Before Treatment with Metronidazole

 

 

 

*After Treatment with Debridement and Metronidazole

*Clinical photos courtesy of Dr. Randolph Valentine, Erie, PA.

 

 

We have conducted four double-blind studies involving combination therapy, that have been funded by the National Institute of Dental and Cranial-facial Research. In each of these studies, we have shown that debridement plus one week of unsupervised usage of systemic metronidazole was superior to debridement plus the usage of placebo. We have in the last three studies, used the reduced need for periodontal surgery as our primary treatment outcome, and were able to show that the combination treatment always significantly reduced the need for periodontal surgery. In a 1996 study, we were curious to see how many surgical procedures could be avoided if we retreated the patient, or the involved teeth. We found that about 80% of the patients did not need periodontal surgery, and that those 20% who still needed surgery, the number of teeth needing surgery was reduced from the initial levels. We found that combination therapy, involving sometimes retreatment with the antimicrobial agents, resulted in a 92% reduction in the need for access surgery about individual teeth, and in a 66% reduction in the number of teeth that needed extraction. Amazingly, those teeth previously requiring extraction now did not even require surgery!

A summary of four double-blind studies in which the metronidazole plus scaling and root planing treatment was compared to placebo medication plus scaling and root planing is shown in the following table. In each of these studies the standard debridement procedures (scaling and root planing) plus the use of a placebo medication, gave results that were statistically inferior in improving the patient's periodontal health, when compared to those obtained when the same debridement procedure was combined with metronidazole. Using the traditional approach, periodontal surgery would most likely be recommended to the patient, whereas, in the case of the metronidazole-treated group, most of the surgical procedures were avoided.

1. Loesche, W.J., Syed, S.A., Morrison, E.C., Kerry, G.A., Higgins, T. and Stoll, J. Metronidazole in Periodontitis. I. Clinical and Bacteriological Results after 15 to 30 weeks. J. Periodontol. 1984;55:325-335

2. Loesche, W.J., Schmidt, E., Smith B.A., Morrison E.C., Caffesse R., and Hujoel P.P. Effect of metronidazole on periodontal treatment needs. J. Periodontol. 1991; 62:247-257

3. Loesche, W.J., Giordano, J.R., Hujoel, P.P., Schwarcz, J., and Smith, B.A. Metronidazole in periodontitis. Reduced need for surgery. J. Clin. Periodontol. 1992;19: 103-112

4. Loesche WJ, Giordano J, Soehren S, Hutchinson R, Rau CF, Walsh L, Schork MA. The non-surgical treatment of periodontal patients. Oral Med Oral Surg Oral Path. 1996;81:533-43

 

 

Non-Surgical Treatment of Periodontal Disease. (Patients have a Choice)

These results, derived from these double-blind clinical studies in which patients were randomly assigned to the treatment groups, indicate that patients with advanced forms of periodontal disease may have a choice between nonsurgical and surgical treatment approaches. The use of antimicrobials in the nonsurgical treatment of periodontal infections should be based on clinical symptoms and subsequent bacteriological diagnosis. We have found that more than 90% of patients with deep pockets, of the depth that would normally require periodontal surgery, or even tooth extraction, have an overgrowth of anaerobic bacterial types in their plaques. We have in these individuals diagnosed an anaerobic infection and treated with metronidazole immediately after all teeth were debrided.

We have followed these patients for five years and find that the results hold up nicely. Almost all the teeth that were spared from surgery as a result of the initial combination therapy, still do not need surgery. In some patients there is evidence of bone gain on radiographs (see illustration below), but this finding needs more thorough analysis. These findings indicate that combination therapy provides long-term benefits. We have interpreted these results as indicating that patients and clinicians now have a choice when it comes to the treatment of advanced forms of periodontal disease. They can treat the periodontal inflammation as a dirty mouth problem and use debridement plus surgery and extraction of hopeless teeth to restore periodontal health, or they can treat the inflammation as an anaerobic infection and use debridement plus short-term antimicrobial therapy to restore health. There are important cost and health considerations in this choice. This choice will become even more important if periodontal inflammation is shown to be a risk factor for heart disease and stroke (See Section on Periodontal Disease and Cardiovascular Disease).