Clinical Relevance Dentin desensitizers and one-bottle self-etching adhesives can significantly reduce dentin hypersensitivity. Clinical desensitizing effectiveness depends on the individual dentin desensitizers/adhesives used. SUMMARY This in vivo study evaluated the desensitizing efficacy of two one-bottle self-etching adhesives, two dentin desensitizers and a placebo (water). Methods: Thirty-one volunteers with 55 hypersensitive teeth were recruited into this clinical investigation. The sensitive teeth were randomly assigned into five groups and treated with one of the following materials: iBond, Heraeus; Xeno V, Dentsply; Gluma desensitizer, Heraeus; Bifluorid 12, Voco; placebo (water). Mechanical and thermal stimuli were used to assess the tooth sensitivity response. Discomfort interval scale (DIS) scores of the sensitive teeth were recorded at three different investigation times (baseline, immediately and one month after treatment). Impressions were taken from the sensitive teeth at all three different investigation times, and replica models were made for the evaluation of the dentin surfaces by scanning electron microscopy. The Friedman test and the Mann Whitney U-test were used to analyze the data. Results: All dental materials significantly reduced the dentin hypersensitivity immediately ( p <0.05) and one month after treatment ( p <0.05), with the exception of Bifluorid 12 for mechanical tooth sensitivity. The placebo (water) only caused a short-term effect on the thermal dentin hypersensitivity ( p <0.05). Topical application of the dentin adhesives/desensitizers on sensitive dentinal areas resulted in occlusion of the patent tubules. Conclusions: The one-bottle self-etching adhesives and dentin desensitizers involved in the current clinical investigation could significantly relieve dentin hypersensitivity immediately and over the course of a month after treatment (except for Bifluorid 12 for tooth mechanical sensitivity). The placebo (water) had an immediate effect on thermal dentin hypersensitivity.
Clinical Relevance Salivary contamination before and after priming could significantly reduce the enamel bond strength of self-etching adhesives. Proper isolation should be performed before and during application of the adhesives and placement of the resin composite. Thorough water-spraying could significantly improve the μTBS of saliva-contaminated enamel. SUMMARY Objective: This study evaluated the effect of saliva contamination on the bovine enamel microtensile bond strengths (μTBS) of four self-etching adhesives. Materials and Methods: The labial enamel surfaces of extracted non-carious bovine incisors were serially wet ground. The enamel surfaces were not contaminated (Group A), contaminated with saliva before/after priming (Groups B/C) or they were water-sprayed after salivary contamination occurred before/after priming (Groups D/E). Four self-etching adhesives and the corresponding resin composites from the same manufacturer (Clearfil SE Bond + Clearfil AP-X, Kuraray Co; Xeno III + Ceram X, Densply; Frog + Ice, SDI; FL Bond II + Beautifil II, Shofu Inc) were applied onto the enamel surfaces. The μTBS tests were performed with a micro tester (BISCO, Inc). The enamel surface was analyzed with AFM (Atomic Force Microscopy) before/after salivary contamination occurred or after the saliva-contaminated enamel was water-sprayed. The data were analyzed using one-way ANOVA, factorial design ANOVA and post hoc Tukey's HSD multiple comparisons. Results: Salivary contamination significantly reduced the μTBS of all the adhesives in the current study ( p <0.001). Thorough water-spraying could significantly restore the μTBS of saliva-contaminated enamel to some degree ( p <0.05) or fully restore it for Clearfil SE Bond, but it could not remove some proteins adsorbed on the enamel surface. Conclusion: Hydrophilic self-etching adhesives are negatively influenced by salivary contamination. Thorough water-spraying could significantly improve the μTBS of the saliva-contaminated enamel. Proper isolation should be performed before and during application of the adhesives and during placement of the resin composite.