Short-term Efficacy of Agents Containing KNO3 or CPP-ACP in Treatment of Dentin Hypersensitivity.

OBJECTIVE: To evaluate the short-term efficacy of agents containing KNO3 or casein phosphopeptide- amorphous calcium phosphate (CPP-ACP) in the treatment of dentin hypersensitivity. METHODS: UltraEZ, containing KNO3 and MI Paste, containing CPP-ACP were applied in this study. The dentin hypersensitivity of 102 subjects was established by a tactile stimulus with a Yeaple preasure probe, and the degree of hypersensitivity was measured using a visual analogue scale (VAS). The patients were divided into four groups: A, B, C and D, using a random number table. UltraEZ, a placebo of UltraEZ, MI Paste, and a placebo of MI Paste were applied to group A, B, C and D respectively for 2 weeks. Dentin hypersensitivity was measured using VAS before the treatment (baseline), on day 2, 7, and 14 during the treatment, and on day 30 and 60 posttreatment. RESULTS: The efficacy of UltraEZ on dentin hypersensitivity was significantly better than that of the corresponding placebo group on day 7 during the treatment, whereas the efficacy of MI Paste exhibited better than that of the placebo group on day 14 during the treatment. However, there were no differences between the efficacy of the two agents on day 14 during the treatment, day 30 or day 60 posttreatment. CONCLUSION: Both UltraEZ and MI Paste had a significant effect on dentin hypersensitivity. UltraEZ showed quicker effects than MI Paste, but MI Paste had a greater sustained action after treatment than UltraEZ.

[Effect of two different desensitizers on bond strength of dentin bonding agents].

OBJECTIVE: To evaluate the bond strength of total-etch or self-etch dentin bonding agents after using two different dentin desensitizers on exposed dentin and investigate the bond interface by scanning electron microscope (SEM). METHODS: Thirty intact and non-carious human third molars were used. The occlusal enamel was removed with the use of a slow-speed saw under water cooling. These teeth were divided into three groups using a table of random numbers with 10 teeth each. These three groups were treated with water (Group C), UltraEZ (Group U) and MI Paste (Group M) respectively. Then 10 teeth from each group were divided into A subgroup (n = 5) bonded with Single Bond 2 adhesive system and B subgroup (n = 5) bonded with Xeno III adhesive system according to manufacturers' instructions. A block of composite resin was build up to 4-5 mm. All the teeth were sectioned occluso-gingivally to obtain bar-shaped specimens with bonded surface area about 0.9 mm x 0.9 mm. The tension of the sample was tested by a microtensile tester at 1 mm/min. The mean values of bond strength were compared using one-way ANOVA. Three samples were chosen randomly from each of six groups for SEM investigation. RESULTS: There were no significant differences between Group U and Group C both in A and B subgroups. While there were significant differences between Group M and Group C in two bonding-agent subgroups. For SEM, the hybrid layer was thin and dense in six groups. Both total-etch and self-etch bonding systems could get fair resin tag infiltration in Group C and Group U. In Group M, the resin tags were relatively shorter and fewer than the anterior mentioned two groups. CONCLUSIONS: UltraEZ had no effect on bond strength of both kinds of dentin bonding agents, while MI paste could diminish bond strength.