In addition, the influence of smoking on the occurrence of S. tigurinus was assessed. Methods Study population Human saliva samples and pooled plaque samples of two different groups, i.e., a non-periodontitis control group (n = 26; 18 females, mean
age 27.7 years, range 16 to 58) and a periodontitis group (n = 25; 14 females, mean age 59.4 years, range 26 to 83) of patients of the Center of Dental Medicine, University of Zurich, Switzerland, were prospectively analyzed. This study was approved by the Ethics committee of the canton Zurich, Switzerland (reference number KEK-ZH-2012-0322) and was conducted according to the guidelines of the Declaration of Helsinki. Pregnant patients or patients under antibiotic therapy were excluded from the study. All patients ML323 cost gave their written informed consent for the study. Clinical data were retrieved from the patients’ medical and dental records. Smoking status was anamnestically registered. Periodontal health status In order to assess the periodontal health status of the patients, a periodontal examination was performed using a pressure-sensitive probe (Hawe Click Probe, Kerr Hawe, Bioggio, Switzerland), which included measurement of probing pocket depth (PPD) at six sites around selleck chemicals each tooth. The dichotomous measurement of bleeding on probing (BOP) and presence of plaque/calculus or overhanging restorations were also recorded. All recordings were made by one calibrated investigator.
Based on this clinical data set, the periodontal
health status was assessed by the periodontal screening index (PSI). This index provides Dynein an overall expression of the health status of the periodontium by assessing the PPD and BOP [15]. In brief, the staging is as follows: grade 0: no pockets >3 mm and no bleeding, grade 1: no pockets >3 mm, but presence of bleeding, grade 2: no pockets >3 mm, presence of bleeding plus the presence of calculus and/or overhanging restorations, grade 3: pockets of 4–5 mm, grade 4: pockets ≥6 mm. The highest score of a subject determined the clinical diagnosis according to the definition of Cutress and co-workers [16]: scores 0, 1, and 2: “no periodontitis”; scores 3 and 4: “periodontitis”. Clinical sample collection Saliva samples of each patient were obtained by paraffin stimulation for 5 min. In addition, one week after the periodontal charting, subgingival plaque samples were collected from the four deepest pockets in the periodontitis group and from the mesial sulcus of the first selleck compound molars in the non-periodontitis control group by paper points and curette method as described earlier [17]. Four subgingival plaque samples were pooled together for each patient. Primer design and TaqMan hydrolysis probes To establish a S. tigurinus specific RT TaqMan PCR, 16S rRNA gene sequences of S. mitis group species available from GenBank database and of S. tigurinus type strain AZ_3aT (GenBank accession number JN004270) and S.