A new portable sulfide monitor with a zinc-oxide semiconductor sensor for daily use and field study

For measuring oral malodor in daily clinical practice and in field study, we developed and evaluated a highly sensitive portable monitor system.

We examined sensitivity and specificity of the sensor for volatile sulfur compounds (VSC) and obstructive gases, such as ethanol, acetone, and acetaldehyde. Each mouth air provided by 46 people was measured by this monitor, gas chromatography (GC), and olfactory panel and compared with each other. Based on the result, we used the monitor for mass health examination of a rural town with standardized measuring.

The sensor detected hydrogen sulfide, methyl mercaptan, and dimethyl sulfide with 10-1000 times higher sensitivity than the other gases. The monitor's specificity was significantly improved by a VSC-selective filter. There were significant correlations between VSC concentration by the sulfide monitor and by GC, and by organoleptic score. Thirty-six percent of 969 examinees had oral malodor in a rural town. Seventy-eight percent of 969 examinees were motivated to take care of their oral condition by oral malodor measuring with the monitor.

The portable sulfide monitor was useful to promote oral health care not only in clinics, but also in field study. The simple and quick operation system and the standardized measuring make it one of parameters of oral condition.