Background: The aim was to compare two different systemic antibiotics regimens adjunctive to non-surgical periodontal therapy when Aggregatibacter actinomycetemcomitans was not detected in the subgingival biofilm. Methods: A total of 58 patients with periodontitis and with no A. actinomycetemcomitans in the subgingival biofilm were treated with full-mouth subgingival instrumentation and either metronidazole (MET; n = 29) or amoxicillin/metronidazole (AMX/MET; n = 29). Probing depth (PD), clinical attachment level (CAL) and bleeding on probing (BOP) were recorded at baseline, as well as after three and six months. Subgingival biofilm and gingival crevicular fluid were collected and analyzed for major periodontopathogens and biomarkers. Results: PD, CAL and BOP improved at 3 and 6 months (each p < 0.001 vs. baseline) with no difference between the groups. Sites with initial PD ≥ 6 mm also improved in both groups after 3 and 6 months (p < 0.001) with a higher reduction of PD in the AMX/MET group (p < 0.05). T. forsythia was lower in the AMX/MET group after 3 months (p < 0.05). MMP-8 and IL-1β were without significant changes and differences between the groups. Conclusion: When A. actinomycetemcomitans was not detected in the subgingival biofilm, the adjunctive systemic use of amoxicillin/metronidazole results in better clinical and microbiological outcomes of non-surgical periodontal therapy when the application of systemic antibiotics is scheduled.

中文翻译：

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未检测到放线杆菌的聚合酶的非手术性牙周疗法联合阿莫西林/甲硝唑或甲硝唑的随机临床试验

背景：目的是比较在龈下生物膜中未检测到聚合酶放线菌的情况下，非手术牙周治疗的两种不同的全身性抗生素治疗方案。方法：对58例牙周炎且龈下生物膜无A.放线菌的患者进行了全口龈下器械和甲硝唑（MET；n = 29）或阿莫西林/甲硝唑（AMX / MET；n= 29）。在基线以及三个月和六个月后记录探查深度（PD），临床附着水平（CAL）和探查出血（BOP）。收集龈下生物膜和龈沟液并分析主要牙周病原体和生物标志物。结果：PD，CAL和BOP在3和6个月时有所改善（相对于基线，每个p <0.001），两组之间无差异。在3和6个月后，两组的初始PD≥6 mm的部位也都有改善（p <0.001），而AMX / MET组的PD降低程度更高（p <0.05）。3个月后，AMX / MET组的T.连翘较低。（p <0.05）。两组间MMP-8和IL-1β无明显变化和差异。结论：何时在龈下生物膜中未检测到放线杆菌，当计划应用全身性抗生素时，阿莫西林/甲硝唑的辅助全身使用可导致非手术性牙周治疗的临床和微生物结果更好。