This study has shown that systemic usage of metronidazole and amoxicillin, when used in conjunction with initial periodontal treatment in adult periodontitis patients, achieves significantly better clinical and microbiological results than initial periodontal treatment alone. Moreover, this research suggests that especially patients diagnosed with P. gingivalis benefit from antibiotic treatment.

Our study provides evidence that the VSC, CH(3)SH and to a lesser extent H(2)S are the main contributors to intra-oral halitosis and that CH(3)SCH(3) is the main contributor to extra-oral or blood-borne halitosis, due to a hitherto unknown metabolic disorder.

The potential use of an adjunctive therapy of metronidazole plus amoxycillin for the subgingival elimination of Actinobacillus actinomycetemcomitans in periodontitis patients was investigated. 22 patients participated in this study, 11 with localized juvenile periodontitis (LJP) and 11 with rapidly progressive periodontitis (RPP). 14 patients had received periodontal treatment in the past. All patients were subgingivally infected with A. actinomycetemcomitans. After mechanical subgingival debridement in combination with the antibiotic treatment, elimination of A. actinomycetemcomitans was achieved in all patients but one. With this one exception, clinical improvements were observed in all patients, resulting in reduced pocket probing depths as well as in a significant reduction in bleeding on probing. Re-examination of 16 patients after 9-11 months revealed that A. actinomycetemcomitans was still undetectable and further clinical improvement was observed. It was concluded that the combination of metronidazole plus amoxycillin is a valuable adjunct to mechanical therapy in A. actinomycetemcomitans associated periodontal infections.

Smoking is a determining factor for the composition of the subgingival microflora in adult patients with periodontitis and may select for a specific cluster of periodontal pathogens, notably Bf, Pm, Fn, and Cr. On the basis of these observations, smoking, among other criteria, may be one parameter to use in deciding to treat refractory periodontitis in smokers with a systemic antibiotic therapy directed against smoking-associated periodontal bacteria.

Implant surface decontamination with 0.12% CHX + 0.05% CPC in resective surgical treatment of peri-implantitis leads to a greater immediate suppression of anaerobic bacteria on the implant surface than a placebo-solution, but does not lead to superior clinical results. The long-term microbiological effect remains unknown.