Global Health and Emergency Care: A Resuscitation Research Agenda—Part 2

At the 2013 Academic Emergency Medicine global health consensus conference, a breakout session to develop a research agenda for resuscitation was held. Two articles are the result of that discussion. This second article addresses data collection, management, and analysis and regionalization of postresuscitation care, resuscitation programs, and research examples around the world and proposes a strategy to strengthen resuscitation research globally. There is a need for reliable global statistics on resuscitation, international standardization of data, and development of an electronic standard for reporting data. Regionalization of postresuscitation care is a priority area for future research. Large resuscitation clinical research networks are feasible and can give valuable data for improvement of service and outcomes. Low‐cost models of population‐based research, and emphasis on interventional and implementation studies that assess the clinical effects of programs and interventions, are needed to determine the most cost‐effective strategies to improve outcomes. The global challenge is how to adapt research findings to a developing world situation to have an effect internationally.     

Improving the effect of NaOCl pretreatment on bonding to caries-affected dentin using self-etch adhesives

Objective

To evaluate the effect of sodium hypochlorite pretreatment on adhesion to normal and caries-affected dentin using self-etch adhesives.

Methods

Forty extracted human molars with coronal carious lesions were used in this experiment. The occlusal dentin surfaces including the caries-affected dentin in each group were treated as follows: group 1, rinsed with water; group 2, treated with 6% NaOCl for 15 s; group 3, treated with 6% NaOCl for 30 s; group 4, application with Accel for 30 s after NaOCl-30 s pretreatment. After rinsing with water and air-drying, the treated dentin surfaces were applied with self-etch systems (Bond Force and Clearfil Protect Bond) according to the manufacturers’ instructions, and built-up with resin composite. After 37 °C water storage for 24 h, the bonded normal or caries-affected dentin areas were isolated to create an hourglass configuration with a cross-sectional area of approximately 1 mm². The specimens were subjected to tensile stress at a cross-head speed of 1.0 mm/min.

Results

NaOCl-15 s pretreatment significantly improved the μTBS of both self-etch adhesives to caries-affected dentin, while the 30 s pretreatment did not affect them. For normal dentin, NaOCl-30 s pretreatment significantly reduced the μTBS of both self-etch adhesives although the 15 s pretreatment did not alter them. Furthermore, the application of Accel with a reducing effect increased the μTBS to normal and caries-affected dentin treated with NaOCl for 30 s.

Conclusions

The effects of NaOCl pretreatment on bonding of both self-etch adhesives were dependent upon type of dentin (normal and caries-affected dentin) and the treatment time.     

Combined effect of smear layer characteristics and hydrostatic pulpal pressure on dentine bond strength of HEMA-free and HEMA-containing adhesives

Objective

This study evaluated the combined effect of smear layer characteristics with hydrostatic pulpal pressure (PP) on bond strength and nanoleakage expression of HEMA-free and -containing self-etch adhesives.

Methods

Flat dentine surfaces were obtained from extracted human molars. Smear layers were created by grinding with #180- or #600-SiC paper. Three HEMA-free adhesives (Xeno V, G Bond Plus, Beautibond Multi) and two HEMA-containing adhesives (Bond Force, Tri-S Bond) were applied to the dentine surfaces under hydrostatic PP or none. Dentine bond strengths were determined using the microtensile bond test (μTBS). Data were statistically analyzed using three- and two-way ANOVA with Tukey post hoc comparison test. Nanoleakage evaluation was carried out under a scanning electron microscope (SEM).

Results

Coarse smear layer preparation and hydrostatic PP negatively affected the μTBS of HEMA-free and -containing adhesives, but there were no significant differences. The combined experimental condition significantly reduced μTBS of the HEMA-free adhesives, while the HEMA-containing adhesives exhibited no significant differences. Two-way ANOVA indicated that for HEMA-free adhesives, there were significant interactions in μTBS between smear layer characteristics and pulpal pressure, while for HEMA-containing adhesives, there were no significant interactions between them. Nanoleakage formation within the adhesive layers of both adhesive systems distinctly increased in the combined experimental group.

Conclusion

The combined effect of coarse smear layer preparation with hydrostatic PP significantly reduced the μTBS of HEMA-free adhesives, while in HEMA-containing adhesives, these effects were not obvious.

Clinical significance

Smear layer characteristics and hydrostatic PP would additively compromise dentine bonding of self-etch adhesives, especially HEMA-free adhesives.