The Periotest is a non-invasive, electronic device which provides an objective measurement of the reaction of the periodontium to a defined impact load applied to the tooth crown. In order for a clinician to interpret Periotest readings, normal physiological values must be known. In traumatology, using the contralateral tooth as a control is impractical, as it too may be affected by injury. The main purpose of this research project was to establish the normal physiological Periotest readings for upper permanent incisor teeth at an age when trauma to teeth is at a peak. This was achieved by taking Periotest readings on healthy upper permanent incisors of 250 children aged between 8-12 years. Test-retest reliability was investigated by taking repeated Periotest readings on the teeth of 13 dental nurses at timed intervals over a 2-h period. The practicality of using the device on children was examined by examiner observation and patient questionnaire. Results showed a wide variation of Periotest readings in healthy upper permanent incisor teeth in 8-12-year-olds, and thus it was felt that normal physiological measurements are best expressed as a range. The test-retest reliability of readings was good (R > 0.85) provided that the repeat reading was taken at least 15 min after the initial reading. The examiner found the equipment easy to use and taking measurement was readily acceptable by the sample group. It was concluded that Periotest could be utilised in traumatology, although the clinician needs to take into account the limitations of the device and the difficulty in interpreting the results.