A pilot assessment of alternative methods of quantifying dental pain with particular reference to dentine hypersensitivity.

OBJECTIVE

The overall aim of this pilot study was to establish the usefulness and comparability of selected verbal and non-verbal methods in the quantification of sensory and affective aspects of dental pain associated with dentine hypersensitivity (DH).

DESIGN

The assessment of dental pain was conducted during an eight week clinical study. Patients were asked to rate their perception of dental pain using selected methods of quantification following tactile (Yeaple Probe-an electronic pressure-sensitive probe) and evaporative (cold air from a dental air syringe) stimulation; together with an overall assessment of perception to daily stimuli (e.g., cold air/water, toothbrushing, sweet and sour foods). The assessment methods used to quantify pain arising from DH were a continuous visual analogue scale (VAS), a 0-10 numerical rating VAS scale (NRS), and a separate intensity verbal descriptor (IVD) and unpleasantness verbal descriptor (UVD) word scales.

SETTING

A specialist department at a postgraduate dental institute and hospital in London, UK.

SUBJECTS

Twenty-five adult patients (8M + 17F) with a mean age of 42.6 years (95 per cent C.I. 38.8 to 46.4 years) attending the department for a clinical study evaluating the efficacy of a desensitising toothpaste agreed to participate.

OUTCOME MEASURES

The study compared a continuous visual analogue scale (VAS), a 0-10 numerical rating visual analogue scale (NRS), and a separate intensity (IVD) and unpleasantness verbal descriptor (UVD) scales to quantify sensory and affective aspects of pain. An unweighted moving average technique was used to construct graphs of the relative frequency of reported severity gradings over a range of 0-10.

RESULTS

The results of the study indicated that cold air appeared to cause greater discomfort to the patient than tactile sensitivity, with the air intensity curve for both IVD and 0-10 VAS peaking at a severity score of 5 while continuous VAS peaked at a score of 3-4. All methods peaked at score 2 for tactile sensitivity. The UVD scale peaked at score 2-3 and again at 6 for air sensitivity, but conformed to the other scales by peaking at score 2 for tactile sensitivity. NRS and IVD scales therefore appeared to provide acceptable alternatives to continuous VAS, but the UVD scale, probably because of the imprecise nature of the words used in the scale, did not.

CONCLUSIONS

This study partially confirms previous conclusions that both verbal and non-verbal techniques quantify sensory and affective aspects of pain. However, the imprecise nature of UVD words provided misleading information in terms of both accuracy and sensitivity (except at very low levels of discomfort), when assessing pain arising from dentine hypersensitivity. In view of the highly subjective data arising from studies of this nature, the use of a moving average technique may be considered a more pragmatic method of analysis.