Method: The experiments were carried out on 8 buccal cervical hypersensitive dentine of premolars in 7 subjects (aged 18-60 yr). The study was approved by the university ethic committee. After identified the exposed hypersensitive dentine area, air-blast and cold (water 4°C) stimulation were applied for 3 s. The subject indicated the intensity of any pain produced by placing a mark on a 100 mm visual analog scale (VAS). Then, silicone rubber impressions (Xantopren®, Heraeus, Germany) were taken of the cervical surface of the tooth. This method of testing dentine sensitivity and the impression were repeated again after application of Colgate® Sensitive Pro-relief™ for 5 min then washing with water and after application of SE bond (Kuraray, Japan). Epoxy resin replicas were made from the impressions and examined in a scanning electron microscope.
Result: For air blast stimulus, both Colgate® Sensitive Pro-relief™ and SE bond, the mean VAS scores decreased significantly (P<0.05, 1way RM ANOVA, Tukey test) from 50.0 ± 22.7 (s.d.) to 36.3 ± 18.5 and to 6.3 ± 17.7 respectively. Cold stimulus, treatment with Colgate® Sensitive Pro-relief™ the mean VAS scores were not significantly different from the baseline value (baseline 63.8 ± 20.7; after Colgate® Sensitive Pro-relief™ 58.6 ± 22.3). SE bond significantly decreased the mean VAS scores to 40.0 ± 31.6 (P<0.05, Tukey test). SEM micrographs after SE bond showed the resin layer covering the exposed dentine.
Conclusion: SE bond reduces the sensitivity to air blast and cold stimuli in hypersensitive dentine patients. Colgate® Sensitive Pro-relief™ could do only air blast but not cold stimulus.