Subjects were grouped as CAD (+) or CAD (-) based on their coronary angiography outcomes. Participants were included in CAD (+) if they had more than 50% reduction in diameter in one or more major epicardial arteries, whereas patients with less than 50% reduction in epicardial artery diameter were enrolled to CAD (-) group.The extent of CAD was measured by the number of main coronary vessels with more than 50% stenosis and occluded left main coronary artery (LMCA) was also noted.Demographic and socioeconomic backgrounds, brushing and interdental cleaning habits, frequency of dental visits, levels of education and medical histories of participants were carefully recorded. Medical histories mainly included cardiovascular risk factors consisting of age, gender, family history of heart disease and myocardial infarction (MI), smoking habits, current medications, body mass index (BMI), hypertension, diabetes, high density protein (HDL) and CRP levels. BMIs of participants were obtained through dividing weight (in kilograms) by the square of height (in meters). Blood samples were collected before angiography in order to analyze biological parameters. Hospital records were consulted to obtain patient information such as existence of hypertension, hyperlipidemia, and diabetes mellitus. Education levels were evaluated based on the last school the patient had graduated from and categorized as no education, secondary school, high school and university.During the examination, remaining teeth count, plaque index (PI), gingival index (GI), bleeding on probing (BOP) and probing pocket depth (PPD) were analyzed. Periodontal measurements were recorded at four sites around each tooth (mesial, mid-buccal, distal, and mid-lingual) by a periodontal probe excluding third molars. Each patient was evaluated for PI, GI, PPD average scores (whole-mouth) and percent of BOP (+) sites. Oral status was categorized in three groups: Group 1 consisted of periodontally healthy subjects and patients with gingivitis. Patients having periodontitis were involved in group 2 and group 3 included edentulous subjects. Periodontal health was defined as the absence of gingivitis or periodontitis. Gingivitis was defined as BOP score of ≥ 10% and probing depth of ≤ 3mm. Diagnosis of periodontitis is based on multiple clinical and radiographic parameters. If a patient has one or more sites of inflammation (BOP), ≥ 2mm radiographic bone loss and ≥ 4mm probing depth; he/she will be diagnosed for periodontitis.
For radiographic analysis, periapical radiographs were taken from teeth with ≥ 4mm PPD using a hand held intra-oral x-ray system operating at 60kVp, 1.5 mA by Dexcowin DX 3000 with a CCD based sensor Trophy RVG ver. 5.0 . The alveolar bone loss was measured by a personal computer with the Microsoft Windows XP operating system with original software. The site where periodontal ligament terminates at the surface of the root was labeled as the alveolar bone crest. Apart from the third molars, all teeth were examined to measure the interval between cementoenamel junction and interproximal alveolar crest, regarding both mesial and distal aspects of each tooth.
