2.1 | Patients with CHD
Out of a population of 308 patients 102 patients with CHD for whom an
CABG surgery was indicated were included at the department of
cardiothoracic surgery of the Heart Centre of the University Clinics
Halle (Saale) in the study between January and October 2017. Follow-up
data were generated from 101 patients between January 2018 to June 2019
(drop out rate 0.98%) (Fig. 1). An experienced cardiac surgeon
diagnosed patients with CHD and checked the inclusion and exclusion
criteria. The following inclusion criteria had to be met: age
> 18 years, at least 60 % stenosis of one of the main
coronary arteries demonstrated by angiography, presence of at least four
teeth. Exclusion criteria were inability to give written informed
consent, subgingival scaling and root planing and/or antibiotic therapy
during the last 6 months prior to the examination, pregnancy, and the
need of antibiotic prophylaxis against endocarditis according to the
criteria of the German Society for Cardiology . Moreover, patients with
diseases or disorders such as current drug or alcohol abuse that
preclude participation in this clinical study according to investigator
judgment were excluded. In order to be able to assess the severity of
the CHD the number of coronaries affected was determined (one-, two- or
threevessel disease). In addition, Canadian Cardiovascular Society (CCS)
stages for angina pectoris were determined. Baseline variables such as
age, smoking status (never, past, current smokers and pack years) and
current or past diseases (e.g., diabetes mellitus, hypertension,
peripheral arterial disease, and dyslipoproteinemia) were assessed as
part of the patient’s medical history. A person who smoked a minimum of
one cigarette per day at the time of questioning was considered to be a
current smoker. A past smoker did not smoke for at least one year at the
time of the survey. The number of pack years was calculated by
multiplying the number of packs of cigarettes smoked per day by the
number of years of smoking. Furthermore, all patients underwent detailed
clinical and biochemical investigation. For instance, intake of drugs
such as lipid lowering drugs, oral anticoagulants, and antiarrhythmics
have been registered. Serum parameters including INR (International
Normalized Ratio) score, hemoglobin (Hb) [mmol/l], hematocrit
[1/l], creatinine [µmol/l], urea [mmol/l], glycated
hemoglobin (HbA1c) [mmol/mol], ], C-reactive protein (CRP)
[mg/dl], leukocytes [Gpt/l], and platelets [Gpt/l] were
recorded.
The dental anamnesis and examination was done one day before the CABG
surgery. The patients were asked about the frequency of brushing teeth
per day and whether they practiced interdental hygiene using dental
floss or interdental brushes. Furthermore, the question was asked
whether periodontal therapy in form of scaling and root planing had ever
been carried out. In order to be able to estimate an increased
occurrence of severe periodontitis within a family, the patients were
asked whether there was premature tooth loss due to tooth loosening
within relatives of the first degree.
Before the dental examination, the study participants were asked to
rinse with an antibacterial mouthwash solution (Chlorhexamed® FORTE
alcohol-free 0.2 %, GlaxoSmithKline Consumer Healthcare GmbH & Co. KG,
Munich, Germany) in order to reduce the risk of bacteremia due to the
probing of dental pockets. The clinical dental assessment involved
determining the plaque index (PI) and bleeding on probing (BOP) . In
plaque index four tooth surfaces were evaluated mesio-buccal,
mid-buccal, disto-bucca, lingual). In bleeding index six sites around
each tooth (mesio-buccal, mid-buccal, disto-buccal, disto-oral,
mid-oral, mesio-oral) were examined. BOP was only evaluated after a
waiting time of 30 seconds after probing.
The measurements for both maximal clinical probing depth (PD= distance
between gingival margin and the apical stop of the probe) and maximum
clinical attachment loss (CAL= distance between the cemento-enamel
junction and the apical stop of the probe) were taken also at six sites
around each tooth. The maximum values for each tooth were taken to
calculate the overall mean per participant. In order to obtain
reproducible results for BOP, PD, and CAL, the two examiners (L.F. and
J.G.) were particularly trained in using a pressure-sensitive dental
probe UNC 15 (0.2N) (Aesculap, Tuttlingen, Germany) and calibrated.
Particular attention was paid that the examiner oriented the probe in
the direction of the tooth axis. The reading was made exactly to the
millimeter. If one measuring point (gingival margin or cemento-enamel
junction) was between two markers of the measuring scale, the
measurement was estimated to 0.5 mm. For the calibration, both examiners
determined PD and CAL twice on five periodontal phantom models (phantom
model A-PB, frasaco GmbH, Tettnang, Germany) and on five patients. To
assess the reproducibility of the double measurements the Bland-Altman
method was used . The difference (d) of the two measurements was
calculated and plotted against the mean of the two measurements. The
measurements are sufficiently reproducible if 95 % of the differences
(d) are in the range d ± 2 x s, where s denotes the standard deviation
of the differences. Regarding our two rater the differences from two
measurements for PD and CAL were to 100 % in this range d ± 2 x s. Thus
the examiner L.F. and J.G. were able to generate reproducible
measurement results.
The clinical periodontitis case definition was held according to the
guidelines of the working group of the Centers for Disease Control and
Prevention (CDC) and according the consensus report of the 2017 world
workshop on the classification of periodontal and peri-implant diseases
and conditions . According CDC a severe periodontitis case was diagnosed
if at least ≥ 2 interproximal sites with CAL ≥ 6 mm (not on same tooth)
and ≥ 1 interproximal site with PD ≥ 5 mm were present. A moderate
periodontitis case was diagnosed if at least ≥ 2 interproximal sites
with CAL ≥ 4 mm (not on same tooth) or ≥ 2 interproximal sites with PD ≥
5 mm (not on one tooth) were present. If no severe or moderate
periodontitis was present, periodontitis was diagnosed as mild or
absent. When using the new classification, the disease stages I to IV
were defined by severity (according to the level of interdental clinical
attachment loss, and tooth loss), complexity and extent and
distribution. However, since no X-ray images were available, the
radiological bone loss could not be taken into account. For this reason
too, periodontitis was not classified according to the progression rates
A to C.
For a more accurate quantification of the root surface affected by
attachment loss and quantification of the inflamed epithelial surface,
both the periodontal epithelial surface area (PESA) and the periodontal
inflamed surface area (PISA) were calculated . For that purpose, a
freely downloadable
(www.parsprototo.info<http://www.parsprototo.info) Excel
spreadsheet was used. In order to calculate PESA, data of CAL and
recession have to be entered. For the calculation of PISA, sites with
BOP have to be recorded additionally.