In the present study, our objective was to quantify the daily duration of vibration exposure from ultrasonic scaling in dental hygienists and to compare different methods of self-estimates to time-recorded measurements. The exposure time was self-estimated by use of diary and interview methods in 10 subjects. We found that the measured total daily exposure time was limited, only on average 12min, with a great variation, however, between and within the subjects. Self-assessed duration of exposure was overestimated, on average three times higher with a diary and even more at an interview (8 times). In conclusion, the objectively measured exposure time was short and clearly overestimated in self-reports.