P31The relationship between the relative amount of Porphyromonas gingivalis in saliva and halitosis

Objectives  Porphyromonas gingivalis is one of the microorganisms that most actively produce CH₃SH and we have reported that subjects with P . gingivalis have higher CH₃SH levels than subjects without P .  gingivalis . However, little is known about the relationship between P . gingivalis levels in saliva and the condition of oral malodor. In this study, we evaluated the association between the relative amount of P . gingivalis in saliva and halitosis in mouth air.
Methods  All of the subjects were patients at the Preventive Dentistry and Breath Odor Clinic of Kyushu Dental College, where they received a periodontal examination. Volatile sulfur compounds (VSC: hydrogen sulfide and methyl mercaptan) were measured using gas chromatography. Saliva samples were collected in a sterile plastic tube over a period of 5 min while the subject chewed on paraffin wax, and were then immediately stored at –80°C until use. Template DNA was obtained from the stored saliva using an Easy-DNA Kit (Invitrogen, CA, USA) according to the manufacturer's instructions. Conventional PCR assays were used to confirm the presence of P . gingivalis . A 5' nuclease TaqMan PCR was used to quantify P . gingivalis in saliva. The relative numbers of bacteria were measured using the comparative threshold cycle method.
Results  We found a quantitative relationship between the P . gingivalis levels in saliva and the condition of halitosis in mouth air.
Conclusion  We analyzed the relationship between the relative amount of P . gingivalis in saliva and oral malodor.