BackgroundThe aim of this study was to assess the efficacy of photodynamic therapy (PDT) as an adjunct to scaling and root planing (SRP) on clinical parameters and microbial composition in subgingival plaque of periodontitis patients.MethodsSeventeen patients were included in this split‐mouth randomized clinical trial. Sites with probing pocket depth (PPD) ≥5 mm in combination with bleeding on probing in different quadrants were randomized into the control group, the group with a single PDT application right after SRP, and the group with three repeated PDT applications 1 week after SRP. The subgingival plaque was collected for 16S rRNA gene sequencing at baseline, Week 2, and Week 8.ResultsSeventeen patients with 60 sites completed this 8‐week follow‐up, and 157 subgingival plaques were successfully analyzed by sequencing. Significant improvements were observed in two primary outcomes: PPD at Week 8 and subgingival microbial composition. Compared to the control group, the repeated‐PDT group showed a notable improvement in PPD, substantial alterations in the microbial profile, including a reduction in α‐diversity and anaerobic bacteria, and an increase in aerobic bacteria at Week 2. Secondary outcomes, such as clinical attachment level and sulcus bleeding index, also showed improvement at Week 8. Furthermore, both the single‐ and repeated‐PDT groups exhibited a decrease in periodontopathogens and an increase in beneficial bacteria compared with baseline.ConclusionPDT promotes changes in the microbial composition of periodontitis patients’ subgingival plaque in a direction favorable to periodontal health, and repeated PDT is a promising adjunctive therapy for periodontal treatment.

中文翻译：

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光动力疗法作为洗牙和根面平整的辅助手段对牙周炎患者龈下菌斑临床参数和微生物组成的功效：一项分口随机临床试验

背景本研究的目的是评估光动力疗法 (PDT) 作为洗牙和根面平整术 (SRP) 的辅助手段对牙周炎患者龈下菌斑的临床参数和微生物组成的疗效。方法本次分口随机试验纳入了 17 名患者临床试验。将探诊袋深度（PPD）≥5 mm且不同象限探诊出血的部位随机分为对照组、SRP后立即进行单次PDT治疗组、SRP后1周重复进行3次PDT治疗组。在基线、第2周和第8周收集龈下菌斑进行16S rRNA基因测序。结果17名患者60个位点完成了为期8周的随访，成功对157个龈下菌斑进行了测序分析。在两个主要结果中观察到显着改善：第 8 周的 PPD 和龈下微生物组成。与对照组相比，重复 PDT 组的 PPD 显着改善，微生物特征发生显着改变，包括减少α‐第 2 周时，多样性和厌氧菌，以及需氧菌的增加。次要结果，例如临床附着水平和沟出血指数，在第 8 周也显示出改善。此外，单次和重复 PDT 组均表现出下降结论PDT促进牙周炎患者龈下菌斑微生物组成向有利于牙周健康的方向变化，重复PDT是一种很有前景的牙周治疗辅助疗法。