Metronidazole does not enhance effective non-surgical treatment of periodontitis

Controlling systematic perioperative anaerobic contamination during sinus-lift procedures by using metronidazole: an innovative approach

BACKGROUND AND OBJECTIVES

Analysis of tomodensitometric controls following sinus grafts clearly demonstrates a quite systematic lack of homogeneity. Sinus contamination by anaerobic bacteria seems almost unavoidable during bone graft surgery, and this problem may jeopardize the healing process. The aim of this study was to characterize in a systematic way the nonhomogeneities observed at 1, 2, or 3 months postsurgery within allogenous sinus grafts, and to assess the possible influence of a 0.5% sterile solution of metronidazole incorporated in the sinus bone graft.

MATERIALS

This clinical study was conducted on 72 patients treated with single or bilateral sinus-lifts: 94 sinus elevations performed with freeze-dried bone allograft (Phoenix, TBF, Mions, France), with (test group) or without (control group) metronidazole. In the test group, each bone graft was hydrated with 2 mL of a 0.5% metronidazole solution, i.e., only 10 mg of metronidazole. All the patients went through a first presurgical computerized tomography (CT)-scan followed by a second scan performed at 1, 2, or 3 months postsurgery (which was used as the preimplant reference scan). For 11 patients, 2 postsurgical CT-scans were performed respectively at 10 days and 2 months. Using an arbitrary gray scale (Arbitrary Densitometric Unit) which functions according to the Hounsfield unit principle, the degree of radiographic homogeneity of the grafts was established. Density scattering provides some information on the homogeneity or nonhomogeneity of the bone graft.

RESULTS

The 12 grafts performed without metronidazole show significant nonhomogeneities at 1, 2, or 3 months. Moreover, when a CT-scan is performed during the first postoperative days (at 10 days), the presence of air bubbles in the graft is confirmed. The tomodensitometric aspects of all grafts treated with metronidazole in this series are absolutely identical: they show a high degree of homogeneity. Sixty-three cases (76.8%) are homogeneous, and 19 cases (23.2%) are significantly homogeneous. The time at which the control scan is performed (10 days, 1, 2, or 3 months) does not seem to influence significantly the degree of homogeneity assessed. In the control group, some inflammatory events associated with facial oedema were observed in 25% of the cases. In the test group, no such event was recorded for the 82 sinus-lifts treated with metronidazole.

CONCLUSION

A possible correlation may exist between the occurrence of non homogeneities within the bone grafts and the anaerobic bacterial contamination. The local use of a very small quantity of metronidazole (equivalent to only 1/20 of a common 200 mg oral tablet) could provide more security when performing sinus-lift procedures and an improved quality of the graft. This protocol should not be considered as an antibiotherapy, but only as way to limit the initial contamination of bone graft.

Clinical and microbiological effects of subgingival administration of two active gels on persistent pockets of chronic periodontitis patients

OBJECTIVES

The present controlled, single-blind study was performed to assess and compare the clinical healing and the microbiological findings following repeated intrasulcular applications of 1% metronidazole or 1% chlorhexidine gels in persistent periodontal pockets previously treated by scaling and root planing (SRP).

MATERIAL AND METHODS

Sixty-three systemically healthy subjects, 25 males and 38 females (mean age 48.4+/-7.2 years), diagnosed for chronic periodontitis were enrolled in this study. They underwent SRP and received oral hygiene instructions (OHI). Three months later, at baseline, a single persistent pocket with a probing depth (PD) of 5-9 mm was chosen as the experimental site in each patient; the subjects were stratified into three matched experimental groups on the basis of the treatment to be performed, which consisted of the subgingival administration of 1% metronidazole gel (MG, n=19), 1% chlorhexidine gel (CG, n=20) or placebo gel (PG, n=24). The treatments consisted of four repeated administrations of subgingival gels, each separated by 7 days, starting at the baseline. Clinical assessment was performed at the baseline and at the 180-day follow-up, after the end of treatment. For microbiological evaluations, subgingival plaque was sampled from the experimental sites at baseline, prior to the first subgingival gel administration, and at 7, 15, 30 and 90 days after the end of the treatment (days 28, 36, 51 and 111 from baseline).

RESULTS

Plaque accumulation did not change significantly in all three groups. Bleeding on probing and clinical attachment levels reduced in the MGs and CGs only. PD was significantly reduced by the same amount in all experimental groups. In the MGs and CGs a remarkable reduction in the frequencies of detection of several periodontopathic micoorganisms was recorded after the treatment. The same was not seen for the PGs.

CONCLUSIONS

Subgingival administration of MG or CG, both at 1%, may have a role in the management of persistent pockets during chronic periodontitis.