Study of the rate of calculus and its contributing factors in patients referring to the Department of oral disease, Dental School, Shahid Beheshti University in fall 2002

Dental calculus has a major role in the development of periodontal disease, so this study was designed to assess the frequency of dental calculus and its precipitating factors and the correlation between them in patients referring to Department of Oral Disease, Shahid Beheshti Dental School in 2002. Methods & Materials: 100 patients without missing in lower incisors and having teeth necessary for Sillness - Loe plaque Index were selected. This descriptive - analytical (cross sectional) study was accomplished by means of interview and observation (examination and laboratory tests). After filling out a data form, the height of calculi on lingual surfaces of lower incisors were measured by using a graded periodontal probe, and the calculus score (c.s) and Sillness - Loe plaque index were calculated for each patient. Then a saliva sample was taken and sent to the laboratory to measure the concentration of calcium. All the data collected by interviewing, examination, and laboratory results were recorded in questionnaires and finally analyzed by SPSS statistical software. The research showed that the frequency of dental calculus was 75%, and the mean calculus score was 30.21±22.9. The mean saliva calcium concentration was 4.96±1.43 mg/dl. Meanwhile, there was a correlation between dental calculus and saliva calcium (2=0.96, P<0.0001). This study revealed that 69.2% of patients with very heavy calculus were male 57.7% of them did not have academic education 80.7% had poor oral hygiene and 69.2% of them had crowding in site of dental calculus. Also 38.5% of them were cigarette smokers (O.R=17.7). The frequency of dental calculus and calculus scores in dental patients are high. It's mandatory to determine and remove calculus contributing factors to achieve an optimum level of oral hygiene and decrease periodontal problems.