title: Persistence of Porphyromonas gingivalis is a negative predictor in patients with moderate to severe periodontitis after nonsurgical periodontal therapy.
abstract: OBJECTIVE
  The aim of this study was to evaluate the quality of prediction for stable results after nonsurgical periodontal therapy by several microbiological variables of the subgingival biofilm and biomarkers of gingival crevicular fluid or oral lavage.
  
  
  METHODS
  Forty-six individuals with moderate or severe chronic periodontitis receiving nonsurgical periodontal therapy were monitored for clinical variables, selected microorganisms, and biomarkers at baseline and 3 and 6 months thereafter. Logistic regression analysis and general linear model (GLM) were applied for analysis of variance and covariance.
  
  
  RESULTS
  At 6 months, 20 patients showed a high response (HR) to treatment (at least 60 % of reduction of numbers of sites with PD >4 mm), whereas 26 did not (low response, LR). All clinical variables were significantly improved at 3 and 6 months within each group (p < 0.001, each compared with baseline). Modeling the impact of Porphyromonas gingivalis, Treponema denticola, and median of MMP-8 on to the response to treatment as continuous variables by GLM showed a significant influence of these variables (p = 0.045) with the strongest influence of P. gingivalis (p = 0.012) followed by T. denticola (p = 0.045) and no association with MMP-8 (p = 0.982). Samples tested positively for P. gingivalis decreased only in HR (3 months: p = 0.003; 6 months: p = 0.002). Calprotectin levels in GCF were lower in the HR group compared with the LR group at 3 months (p = 0.008) and at 6 months (p = 0.018).
  
  
  CONCLUSIONS
  Persistence of P. gingivalis combined with a high GCF level of calprotectin may have a negative predictive value on response to periodontal therapy.
  
  
  CONCLUSIONS
  Microbiological diagnostics for P. gingivalis before and 3 months after SRP may have a predictive value on response to periodontal therapy. The combination with MMP-8 in oral lavage or preferably calprotectin in GCF might give additional information.
authors: Department of Periodontology, School of Dental Medicine, University of Bern, Freiburgstrasse 7, 3010, Bern, Switzerland. sigrun.eick@zmk.unibe.ch.
authors: Sigrun
authors: http://orcid.org/0000-0002-4619-2461
authors: S
authors: Eick
authors: Department of Periodontology, School of Dental Medicine, University of Bern, Freiburgstrasse 7, 3010, Bern, Switzerland.
authors: Ayse
authors: A
authors: Mathey
authors: Centre for Periodontology, Department of Cariology, Endodontology and Periodontology, University Hospital of Leipzig, Liebigstr. 12, 04103, Leipzig, Germany.
authors: Karolin
authors: K
authors: Vollroth
authors: Centre for Periodontology, Department of Cariology, Endodontology and Periodontology, University Hospital of Leipzig, Liebigstr. 12, 04103, Leipzig, Germany.
authors: Martin
authors: M
authors: Kramesberger
authors: Ressort Research, School of Dental Medicine, University of Bern, Bern, Switzerland.
authors: Walter
authors: W
authors: Bürgin
authors: Department of Periodontology, School of Dental Medicine, University of Bern, Freiburgstrasse 7, 3010, Bern, Switzerland.
authors: Anton
authors: A
authors: Sculean
authors: Department of Periodontology, School of Dental Medicine, University of Bern, Freiburgstrasse 7, 3010, Bern, Switzerland.
authors: Christoph
authors: C
authors: Ramseier
authors: Centre for Periodontology, Department of Cariology, Endodontology and Periodontology, University Hospital of Leipzig, Liebigstr. 12, 04103, Leipzig, Germany.
authors: Holger
authors: H
authors: Jentsch
mesh_terms: D000328:Adult; D000368:Aged; D018441:Biofilms; D015415:Biomarkers / Q000032:analysis; D005260:Female; D005883:Gingival Crevicular Fluid / Q000382:microbiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010518:Periodontitis / Q000382:microbiology* / Q000628:therapy*; D016966:Porphyromonas gingivalis / Q000302:isolation & purification*
chemical_list: D015415:Biomarkers
keywords: Biomarkers; Chronic periodontitis; Microbiological diagnostics; Porphyromonas gingivalis; Response to treatment