Method: 300 subjects assisted at the Restorative Dentistry Clinic of the University of São Paulo were eligible to participate in this study,based on the inclusion and exclusion criteria.The subjects completed a questionnaire regarding their personal information, the presence of DH and some of its related risk factors. After, they were clinically examined by three calibrated investigators. To confirm the presence of DH, the subjects were further evaluated with the use of a probe and cold air from a triple syringe. Frequency distribution and cross-tabulation tables were constructed. Statistical analysis was performed with the Chi-square test and the Odds Ratio (OR), considering a 95% Confidence Interval (CI).
Result: The prevalence of DH was 46%. Females presented higher prevalence of hypersensitivity than males (OR=2.66; CI=1.64-4.31; p<0.01). No difference was found between different age groups (18-77 years old; mean age (SD): 40.42(±13.75). The left posterior region, either superior as inferior, was reported to be the most frequent regionaffected by DH (41% and 35%, respectively). Cold was the commonest pain-inducing stimulus (87%) and 51% of the subjects with DH described their pain as a mild discomfort. Toothbrush applying excessive force(OR=3.02; CI=1.87-4.89; p<0.01), bruxism (OR=3.85; CI=2.22-6.67; p<0.01) and gastroesophageal reflux (OR=3.15; CI=1.63-6.08; p<0.01) were strongly correlated with DH, while no association could be found between DH and the high consumption of acidic fruits and drinks, frequency of toothbrushing and different brush bristle hardness.
Conclusion: The prevalence of DH was particularly high, affecting almost half of the population studied. The risk factors for DH in this population were: gender (female), toothbrushing applying excessive force, bruxism and gastroesophageal reflux.