Effect of different polishing systems on the surface roughness of various bulk-fill and nano-filled resin-based composites: An atomic force microscopy and scanning electron microscopy study.

The aim of the study was to evaluate the effects of different polishing systems on the surface roughness of various bulk-fill and nano-filled resin-based composites using different methods. For the study, a total of 192 disc-shaped samples (10-mm wide and 2-mm thick) were prepared from four different bulk-fill composites (Filtek Bulk Fill, X-tra fil, Beautifil-Bulk Restorative and Fill Up) and two nano-filled resin-based composites (Ceram.x SphereTEC and Filtek Z550).

The environmental impact of governance: a system-generalized method of moments analysis.

To investigate the role of governance on environmental quality, two hypotheses are developed; when good governance practices dominate governance structures, then improvement in governance levels leads to better environmental outcomes, and when bad governance practices dominate governance structures, then improvement in governance levels leads to deterioration in environmental outcomes. To test these hypotheses for 115 countries clustered as high, middle, and low income over the period of 2000 to 2015, system generalized method of moments is employed. The results show that an improvement in governance increases environmental quality in high income countries, while it decreases environmental quality in middle- and low-income countries.

The role of financial development on carbon emissions: a meta regression analysis.

The study analyzes the role of financial development on CO2 emissions based on the primary studies in the existing literature. However, the heterogeneity in reported effect size estimates of the primary studies complicates to test the competing hypotheses for the role of financial development on CO2 emissions. The paper tries to determine and quantify the representative empirical genuine effect of financial development on CO2 emissions, if any.

Bond strength of self-adhesive resin cement to root dentin. Comparison of photon-initiated photoacoustic streaming technique with needle and ultrasonic irrigation.

Objective: The aim of this study was to investigate the effects of photon-initiated photoacoustic streaming (PIPS) with various irrigating solutions on the bond strength of a self-adhesive resin cement to root dentin.

Materials And Methods: Seventy-two mandibular premolar roots were divided into six groups after post space preparation and treated with a needle irrigation with distilled water and NaOCl, ultrasonic irrigation with NaOCl, PIPS with NaOCl, PIPS with EDTA and PIPS with distilled water at 0.3 W, 15 Hz and 20 mJ per pulse for 60 s.

Comparison of bond strength of self-etch adhesive to pulp chamber dentin after placement of calcium hydroxide and various antibiotic pastes.

Objective: The aim of this study was to evaluate the effect of calcium hydroxide, double antibiotic paste (DAP) and triple antibiotic paste (TAP) with minocycline, cefaclor and amoxicillin on the micro tensile bond strength (µTBS) of self-etch adhesive to pulp chamber dentin.

Materials And Methods: Sixty mandibular first molars were cut horizontally and randomly divided into a control group and five experimental groups, which received an intra-canal dressing, as follows: calcium hydroxide, DAP, TAP with minocycline, TAP with cefaclor and TAP with amoxicillin. After storing the specimens for 4 weeks, the medicaments were removed by irrigation with 10 mL each of the following solution: 2.