Method: After institutional review and informed consent, 150 adult volunteers who reported natural tooth sensitivity were enrolled in a screening study to assess differential pain responses to two provocative stimuli (air and water). Oral hygiene was not standardized, except that subjects were instructed to avoid daily hygiene on the morning of evaluation. An interview and an oral examination were conducted to identify subjects with recession sites, which served as test sites for this study. Each test site was first stimulated with a 1-sec application of cool air (~21oC, 40-60 psi) using a dental syringe, after which, a single drop of refrigerated (~2oC) water from a 3 mL hypodermic syringe. Site response was measured immediately after each stimulus by a trained clinical examiner using a standard 4-point scale (Schiff) that categorized discomfort from none-to-painful.
Result: A total of 86 subjects (mean age of 48.1 years, 47% female) exhibited a sensitivity response at recession sites for air and/or water stimuli. Subjects averaged 3.73 (SE 0.43) sites with air response versus 2.21 (SE 0.25) for water, ranging from 0 to 16 for air and 0 to 13 for water. The total Schiff sum per subject averaged 5.52 (SE 0.72) for air and 3.14 (SE 0.34) for water, while mean Schiff scores per subject averaged 1.12 (SE 0.07) for air and 0.80 (0.07) water. Subject-level correlations between air and water stimuli were high for the number of sensitivity sites (r = 0.71) and total Schiff sum (r = 0.72). Mean Schiff level revealed an insignificant subject-level correlation.
Conclusion: In a general population without acclimation, use of two different stimuli (air and water) yielded consistent clinical sensitivity occurrence of teeth within-subjects and for total Schiff sum, while simple means yielded low subject-level consistency between stimuli.