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Purpose: The aim of this study was to investigate the effect of Teethmate Desensitizer (TD), an aqueous slurry of calcium phosphates, on the pre- and postcementation sensitivity of contralateral premolars prepared for full-coverage restorations.Materials and Methods: In this clinical study, using a split-mouth design, 20 patients were allocated and two contralateral vital premolars per patient were randomly assigned to treatment with TD and placebo (PLA; distilled water). One day after preparation and temporization, sensitivity (PRE) upon air blast (AB) and probe scratch (PS) was determined using a 10-cm-long visual analog scale (VAS). The trial was double-blinded; neither the patient nor the investigator knew the treatment performed. Sensitivity was assessed immediately after treatment, before seating the final crowns after 1 week, and 1 month after cementation. Statistical data analysis was performed with one-way analysis of variance followed by Tukey post hoc test and two-sided paired t test. Statistical significance was determined at α < .05.Results: VAS scores upon stimulation with AB and PS were significantly lower at POST and 1 week, and with AB after 1 month. TD-treated teeth showed significantly less sensitivity than PLA. At the postcementation recall, TD and PLA were not significantly different and the average pain scores were almost 0.Conclusion: Treatment of teeth prepared for full crown restorations with TD can significantly reduce pre- and postcementation sensitivity. [ABSTRACT FROM AUTHOR]

Stabilizing high dispersions of catalytically active metals is integral to improving the lifetime, activity, and material utilization of catalysts that are periodically exposed to high temperatures during operation or maintenance. We have found that annealing palladium-based core@shell catalysts in air at elevated temperatures (800 °C) promotes the redispersion of active metals into highly dispersed sites, which we refer to as halo sites. Here, we examine the restructuring of Pd@SiO2 and Pd@CeO2 core@shell catalysts over successive 800 °C aging cycles to understand the formation, activity, nanoscale structure, and stability of these palladium halo sites. While encapsulation generally improves metal utilization by providing a physical barrier that promotes redispersion over agglomeration, our cycled aging experiments demonstrate that halo sites are not stable in all catalysts. Halo sites continue to migrate in Pd@SiO2 due to poor metal–support bonding, which leads to palladium agglomeration. In contrast, halo sites formed in Pd@CeO2 remain stable. The dispersed palladium also synergistically stabilizes the ceria from agglomerating. We attribute this stability, in addition to an observed improvement in catalytic activity, to the coordination between palladium and reducible ceria that arises during the formation of halo sites. We probe the importance of ceria oxidation state on the stability of halo sites by aging Pd@CeO2 after it has been reduced. While some halo sites agglomerate, we find that returning to air aging mitigates the loss of these sites and catalytic activity. Our findings illustrate how nanoscale catalyst structures can be designed to promote the formation of highly stable and dispersed metal sites. [ABSTRACT FROM AUTHOR]

Nearly all published reports and clinical studies of hemodialysis solute kinetics are confined to thrice-weekly dialysis schedules. Over the past 40 years, clinical experience with dialysis treatments given three times per week has expanded enormously, but it was not until the Hemodialysis (HEMO) study results were revealed that nephrologists became fully aware of the limits of usefulness of infrequent dialysis. In light of continued reports of improved quality of life and survival with daily dialysis, it appears that the limits of thrice-weekly dialysis may be extended when treatments are given more often. Analysis of solute kinetics during and between dialyses supports the notion that a more frequent schedule delivers more efficient dialysis and that methods can be developed to allow a comparison of risks among patients treated 3–7 days per week. One such method, based on the concept of solute seclusion, suggests that at the currently established minimum standard dose, approximately 50% of the improvement in solute control afforded by seven treatments per week is achieved by increasing the frequency to four treatments per week. The same model shows that seven treatments per week afford an improvement in solute control that is approximately 80% as effective as continuous dialysis. These conclusions are similar to those derived from a completely different model based on peak concentration toxicity. Neither of these models has been clinically tested, so caution must be advised when treating individual patients. [ABSTRACT FROM AUTHOR]