ORIGINAL ARTICLE Six-month results following treatment of aggressive periodontitis with antimicrobial photodynamic therapy or amoxicillin and metronidazole Nicole Birgit Arweiler & Malgorzata Pietruska & Jan Pietruski & Ana Skurska & Eva Dolińska & Christian Heumann & Thorsten Mathias Auschill & Anton Sculean Received: 6 October 2013 /Accepted: 16 January 2014 /Published online: 4 February 2014 # Springer-Verlag Berlin Heidelberg 2014 Abstract Objective The use of antibacterial photodynamic therapy (aPDT) additionally to scaling and root planing (SRP) has been shown to positively influence the clinical outcomes. However, at present, it is unknown to what extent aPDT may represent a potential alternative to the use of systemic antibiotics in nonsurgical periodontal therapy in patients with aggressive periodontitis (AP). The aim of this study was to evaluate the outcomes following nonsurgical periodontal ther- apy and additional use of either aPDT or amoxicillin and metronidazole (AB) in patients with AP. Material and methods Thirty-six patients with AP displaying at least three sites with pocket depth (PD) ≥6 mm were treated with SRP and either systemic administration of AB for 7 days or with two episodes of aPDT. The following clinical param- eters were evaluated at baseline and at 6 months: plaque index (PI), bleeding on probing (BOP), PD, gingival recession (GR) and clinical attachment level (CAL). Results Thirty-five patients have completed the 6-month eval- uation. At 6 months, mean PD was statistically significantly reduced in both groups (from 5.0±0.8 to 3.0±0.6 mm with AB and from 5.1±0.5 to 3.9±0.8 mm with aPDT (p<0.001)). AB yielded statistically significantly higher improvements in the primary outcome parameter PD (p<0.001) when com- pared to aPDT. The number of pockets ≥7 mm was reduced from 141 to 3 after AB (p<0.001) and from 137 to 45 after aPDT (p=0.03). Both therapies resulted in statistically signif- icant reductions in all parameters compared to baseline. Conclusion While both treatments resulted in statistically sig- nificant clinical improvements, AB showed statistically sig- nificantly higher PD reduction and lower number of pockets ≥7 mm compared to aPDT. Clinical relevance In patients with AP, the two times applica- tion of aPDT in conjunction with nonsurgical periodontal therapy cannot be considered an alternative to the systemic use of amoxicillin and metronidazole. Keywords Photodynamic therapy . Nonsurgical periodontal therapy . Scaling and root planing . Systemic antibiotics . Amoxicillin . Metronidazole . Randomized controlled clinical study Introduction Nonsurgical periodontal therapy involving scaling and root planing (SRP) aims to remove or disrupt the bacterial biofilm, thus reducing the load of periodontal pathogenic microorgan- isms [1, 2]. Longitudinal studies have provided evidence for the clinical efficacy of nonsurgical periodontal therapy in the treatment of chronic periodontitis (CP) [3, 4]. Aggressive periodontitis (AP)—although its prevalence is low—is usually characterized by a rapid destruction of peri- odontal tissue support involving the cementum, periodontal ligament and alveolar bone and deterioration of tooth progno- sis eventually leading to tooth loss [5]. In most patients diagnosed with AP, mechanical debridement alone is not N. B. Arweiler (*) : T. M. Auschill Department of Periodontology, Philipps-University, 35039 Marburg, Germany e-mail: arweiler@med.uni-marburg.de M. Pietruska : J. Pietruski : A. Skurska : E. Dolińska Department of Periodontology, Medical Academy Bialystok, Bialystok, Poland C. Heumann Department of Statistics, LMU Munich, Munich, Germany A. Sculean Department of Periodontology, Dental School, University of Bern, Bern, Switzerland Clin Oral Invest (2014) 18:2129–2135 DOI 10.1007/s00784-014-1193-6