Effect of preheated composite resin luting agents on the color of ceramic laminates.

This in vitro study evaluated the effects of preheating, ultrasound application, and composite resin luting agent composition on the optical characteristics of feldspar ceramic laminates. The hypothesis was that the optical properties of the ceramic-luting agent-substrate unit would be affected by the composition of the luting material and use of ultrasound. Preheated restorative composite resins Charisma, IPS Empress Direct, and Filtek Z350 were used, with unheated RelyX Veneer resin cement serving as the control. The response variables for the physical properties of the materials were degree of conversion (n = 3 per material) and viscosity (n = 3 per material). Seven groups were generated based on the tested luting agent and the use of ultrasound. Color parameters were evaluated with a spectrophotometer at 3 timepoints (before luting [baseline], 24 hours after luting, and 1 month after luting), and color change was calculated according to the Commission Internationale de l'Eclairage (CIE) CIEDE 2000 formula and translucency parameters. The statistical significance of color change and viscosity was measured using 2-way analysis of variance (ANOVA), while the degree of conversion was measured using 1-way ANOVA. For translucency parameters, ANOVA on ranks and post hoc Duncan multiple range tests were performed. The control group showed the highest degree of conversion, while Filtek Z350 showed the highest viscosity. Statistically significant differences in color change between luting material groups were found under most conditions (P < 0.001), but there was no difference in translucency parameters between the luting materials (P = 0.446). Overall, the use of preheated composite resins as luting agents offers similar to poorer performance than conventional resin cement.

Related factors to atazanavir plasma levels in a cohort of HIV positive individuals with undetectable viral load.

OBJECTIVE: To evaluate the factors associated with plasma concentrations of atazanavir (ATV) in a cohort of well-controlled HIV infected subjects (undetectable viremia). DESIGN: Cross-sectional study where 69 subjects were consecutively enrolled between April and November, 2011. METHODS: Patients had to be on atazanavir for at least six months, undetectable viral load for a period equal to or longer than 12 months, T CD4+ lymphocyte count higher than 200 cells/mm(3), and aged between 18 years and 70 years old. Exclusion criteria were pregnancy, any neurologic disease, active opportunistic disease, hepatitis or cancer. Atazanavir plasma levels were measured by ultra-performance liquid chromatography. RESULTS AND DISCUSSION: Overall, 54 patients (mean age of 47 years and 50% women) were included in the analysis. Those without ritonavir (unboosted atazanavir) had statistically lower plasma concentrations than those with ritonavir boosted atazanavir (p=0.001) and total and indirect bilirubin were statistically associated with plasma concentration of atazanavir (r=0.32 and r=0.33 respectively; p<0.05 in both cases). No statistical association was found among gender, ethnicity, age, weight, body mass index (BMI), lipid profile, and the plasma concentration of atazanavir. CONCLUSION: In summary, as expected, concomitant ritonavir use was the only factor associated with atazanavir plasma levels. Prospective studies with a larger sample size might help to observe an association of atazanavir concentrations to other characteristics such as body weight, since the p-value showed to be close to significance (p=0.068).

Related factors to atazanavir plasma levels in a cohort of HIV positive individuals with undetectable viral load

OBJECTIVE: To evaluate the factors associated with plasma concentrations of atazanavir (ATV) in a cohort of well-controlled HIV infected subjects (undetectable viremia). Design: Cross-sectional study where 69 subjects were consecutively enrolled between April and November, 2011. METHODS: Patients had to be on atazanavir for at least six months, undetectable viral load for a period equal to or longer than 12 months, T CD4+ lymphocyte count higher than 200 cells/mm³, and aged between 18 years and 70 years old. Exclusion criteria were pregnancy, any neurologic disease, active opportunistic disease, hepatitis or cancer. Atazanavir plasma levels were measured by ultra-performance liquid chromatography. RESULTS AND DISCUSSION: Overall, 54 patients (mean age of 47 years and 50% women) were included in the analysis. Those without ritonavir (unboosted atazanavir) had statistically lower plasma concentrations than those with ritonavir boosted atazanavir (p = 0.001) and total and indirect bilirubin were statistically associated with plasma concentration of atazanavir (r = 0.32 and r = 0.33 respectively; p < 0.05 in both cases). no statistical association was found among gender, ethnicity, age, weight, body mass index (BMI), lipid profile, and the plasma concentration of atazanavir. CONCLUSION: in summary, as expected, concomitant ritonavir use was the only factor associated with atazanavir plasma levels. prospective studies with a larger sample size might help to observe an association of atazanavir concentrations to other characteristics such as body weight, since the p-value showed to be close to significance (p = 0.068).