This article describes an exploration of the concept of ‘oral freshness’ for as far as it is important in oral care. It intends to consider the most important mouth sensations and cognitive connotations, including (but not restricted to) the well-known effect of menthol in toothpaste.
Two aspects were given attention:
(1) The attributes that together form the concept of oral freshness were investigated using a ‘personal construct approach’(Kelly 1955). This method consists of unbiased, structured interviews with subjects, and ultimately yields attribute dimensions that the subjects have in common.
(2) The intensity of the freshness sensation over time was investigated using the Time-Intensity method. Subjects gave repeated freshness judgments every few seconds after the intake of a freshness-related stimulus, and continued to do so after the stimulus had left their mouth. In addition we asked for ‘overall’ freshness judgments directly after the TI-measurements and after 2 months.
The results confirm that ‘oral freshness’ is a complex concept. We identified 6 attributes, some of which were perceptual/physiological and some cognitive in nature: ‘water’-ness, cool/cold-ness, taste (menthol-ness), clean-ness, smell, energy (texture and touch, e.g., bubbles). Different persons will generally give different importance weights to each of these 6 attributes.
Time-intensity measurements show that temperature, menthol-content and, to some extent, the presence of bubbles (energy) influence the momentous sensation of freshness. It appears, however, that in the way freshness is remembered after a few months, mainly cleanness and taste (menthol-ness) are important. Apparently, people tend to value (temporary) sensory input during the actual freshness experience, but tend to remember the freshness result in the longer run.