ABSTRACT
The present study was performed to evaluate the effect of one week metronidazole treatment on patients with advanced periodontal disease. Thirteen patients [three males and ten females] were selected in the study. Clinical and microbiological evaluations were carried out initially at the pretreatment visit, then repeated at 2 and 15 weeks after metronidazole treatment. Clinical measurements of pocket depth and attachement level was done using Ramfjord procedures [1967] [12]. In addition, microbiological samples were obtained from the most severely involved sites as shown by X-ray picture to detect the effect of metronidazole on anaerobic and facultative organisms. The results of this study revealed an improvement in clinical parameters as indicated by reduction in pocket depth associated with an apparent gain of attachement. This suggested that metronidazole permitted a type of disease resolution at the base of deep pockets. In addition, the presentinvestigation revealed that metronidazole eliminated anaerobic organisms from subgingival microbiota and reduced some of the facultative organisms such as streptococcus mutans, streptococcus sangius and streptococcus salivarius. These findings emphasize that the elimination of anaerobic organisms was responsible for the improved periodontal health; whereas the suppression but not the elimination of facultative species in the plaque were not primarily responsible for signs of disease observed. In addition, it may suppress the pathogenic flora so that when the antimicrobial therapy stops, a non pathogenic flora may reestablish in the subgingiral area. The metronidazole unique spectrum of activity against anaerobes involved in periodontal disease coupled with favorable clinical response to the short term treatment inelicate that this agent will have valuable usage in dentistry. However, long-term studies are needed to disclose if discontinuation of metronidazole therapy will lead to reestablishment of a subgingival microbiota inductive to progressive periodontal disease