Systemic antimicrobial treatment and guided tissue regeneration. Clinical and microbiological effects in furcation defects
This study's aim was to compare the effects of testing an antibiotic with a nonresorbable membrane versus conventional treatment in terms of attachment gains, recession, and bacterial samples in grade II furcation defects.
Ten patients were participants in this placebocontrolled, double-blind, prospective longitudinal study. The study included 20 mandibular molars with furcation defects split-mouth design, and were followed for 50 weeks. Half the patients received the antibiotic Ornidazole, which has properties similar to metronidazole. The antibiotic was administered for two weeks starting at week two.
More horizontal attachment gain and increase in bone density were obtained in patients receiving the active drug than in patients receiving the placebo. The group of membrane plus antibiotic resulted in 0.7 mm mean recession increase and a 1.2 mm decrease in horizontal probing depth. No significant difference was found between the groups in terms of recession, but horizontal attachment gain and bone density showed positive effects in the active drug group over placebo. The microbiological testing showed sites treated with membranes generally tended to be positive for the target organisms more often than the sites treated without a membrane. No significant differences in morphotypes, of the 15 types tested, were found in treatment groups.
Does this study show that the use of systemic antibiotic helps with conventional and GTR therapies for grade II furcations? Unfortunately, in this study we don't see the cause-and-effect benefits of the antibiotic. A marked change in the flora along with differences in attachment gains would help us to justify this form of therapy. But in this study, no changes in the microflora could be found, and slight differences, although significant with statistics, were found in horizontal measurements. Remember that this is a small sample size, and measuring horizontal attachment has been shown to be inaccurate (Eickholz and Staehle, 1994). [D.H.]
Mombelli A., U. Zappa, U. Bragger, and N. Lang, J Clin Periodont, 23:386,1996