clinical laboratory tests to saliva samples, and examined
the feasibility and reliability of these methods for the
screening of periodontal disease.
Materials and Methods
Study population
Subjects working at the municipal office of Honjo City,
Saitama Prefecture, Japan, who underwent annual medical
check-ups at Honjo Comprehensive Health Care Center
were enrolled in the study. The study population comprised
137 males and 50 females with a mean age of 37.2 ± 9.6
(range; 21-60) years. The mean number of remaining teeth
in each subject was 27.5 ± 1.06 (range; 21-32). Smoking
status was investigated by interview. Among the subjects,
46 (24.6%) were current smokers, 41 (21.9%) were previous
smokers, and 100 (53.5%) had never smoked. Eighteen
(9.6%) of the subjects had systemic diseases; however,
diseases that affect periodontal conditions, such as diabetes,
were not included. Therefore, all these subjects were
included in the analysis.
Clinical examination, diagnosis, and saliva
sampling
Before the clinical examination, a 5-min stimulated
saliva sample was collected by chewing a gum base
containing no fragrant or taste ingredients. Six dentists
conducted periodontal pocket probing on all the subjects
using disposable WHO probes. Before the examination,
all the participating dentists were obliged to attend a
training course in probing depth determination. The kappa
value for probing depth was between 0.67 and 0.80. The
diagnostic criteria used in this study were as follows:
Gingivitis was diagnosed when bleeding was observed after
periodontal pocket probing; moderate periodontitis was
diagnosed when at least one probing depth was 4-5 mm;
and severe periodontitis was diagnosed when at least one
probing depth was 6 mm or more.
Before sampling, informed written consent was obtained
from every subject for analysis of the saliva samples. This
study was approved by the ethics committee of Nippon
Dental College. Saliva samples were immediately
transferred to a refrigerated container at 4°C and then
transported to the laboratory. The following measurements
were carried out on the same day.