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Background: The clinical evidence relate the effect of associating the in-office and at home vital tooth whitening, describing positive effects on tooth color change and reduction of dental sensitivity. Objective: The purpose of this randomized double-blind clinical trial was to evaluate the effect on the shortened application of in-office vital tooth whitening combined with different concentrations of at-home peroxides in the final tooth color change and dental sensitivity. Methods: Randomized double-blind clinical trial with 120 participants between 18-65 years, allocated in four tooth whitening treatment groups: G1= Carbamide Peroxide 10% + Hydrogen Peroxide 40%, G2= Carbamide Peroxide 15% + Hydrogen Peroxide 40%, G3= Carbamide Peroxide 20% + Hydrogen Peroxide 40%, G4= Hydrogen Peroxide 10% + Hydrogen Peroxide 40% was conducted. Tooth color was measured at baseline and dental sensitivity and tooth color change during and after treatment. Results: No statistical significant differences were found in tooth color change (superior arch p= 0.183 / inferior arch p= 0.374), and in dental sensitivity (p=0.268). Conclusion: Reducing the application time of in-office whitening, combined with in-home products was effective in improving the color. All groups resulted in identical final color change and dental sensitivity. Clinicaltrials.gov: NCT02682329 Available from: https://clinicaltrials.gov/ct2/show/NCT02682329?term=hydrogen+peroxide.

El proyecto USAID Leer es una intervención de lectura y escritura en escuelas públicas de la República Dominicana en respuesta a sus bajos niveles de comprensión lectora. el objetivo del estudio fue determinar la eficacia del proyecto USAID Leer a través de dos estudios transversales (al iniciar el proyecto y en la mitad). Se realizó un estudio experimental con aleatorización de grupos (experimental vs. control) y una estimación del contrafactual basada en la evaluación de línea base. Participaron 2,399 alumnos de segundo grado para línea base, y 2,359 alumnos de cuarto grado para línea media. Se evaluaron comprensión lectora, habilidades precursoras a la misma (comprensión oral, conciencia fonológica, conocimiento de letras, lectura de palabras por minuto, lectura de pseudopalabras por minuto y fluidez), y habilidades cognitivas generales (memoria de trabajo de palabras y memoria de trabajo de pseudopalabras). Dentro de los resultados se destaca que no hubo diferencias entre los grupos durante la línea base. En la línea media, el grupo experimental obtuvo mejores puntuaciones que el grupo control en comprensión oral, conciencia fonológica, conocimiento de letras, lectura de palabras y pseudopalabras por minuto y memoria de trabajo de pseudopalabras. No hubo diferencias entre los grupos en fluidez ni en comprensión lectora. Se concluyó que la intervención fue efectiva, pero aún no ha alcanzado el umbral necesario para que sus efectos se reflejen más allá de las habilidades precursoras de la comprensión lectora. Los resultados se interpretan desde la teoría de la automatización lectora y la necesidad de mayor práctica lectora de los alumnos en proceso de alfabetización.

ObjectivesThis study aimed to identify the risk factors associated with preterm birth, and to determine the prevalence of preterm births in the Dominican Republic.DesignCase-control study.SettingsSeven National Reference Hospitals from different regions of the Dominican Republic.ParticipantsA probabilistic sampling of both cases and controls was performed with a ratio of 2.92:1, and a power analysis was performed with α=0.05, P1=0.5, P2=0.6, and β=0.08, to yield a distribution of 394 cases and 1150 controls. Estimation of gestational age was based on neonatologist reports.Primary outcome measuresA protocol was created to obtain maternal and obstetric information.ResultsThe main risk factors were a family history of premature births (p<0.001, OR: 14.95, 95% CI 8.50 to 26.29), previous preterm birth (p=0.005, OR: 20.00; 95% CI 12.13 to 32.96), advanced maternal age (over 35 years; p<0.001, OR: 2.21; 95% CI 1.57 to 3.09), smoking (p<0.001, OR: 6.65, 95% CI 3.13 to 13.46), drug consumption (p=0.004, OR: 2.43, 95% CI 1.37 to 4.30), premature rupture of membranes (p<0.001, OR: 2.5) and reduced attendance at prenatal consultations (95% CI 6 to 7, Z=−10.294, p<0.001).ConclusionMaternal age greater than 35 years, previous preterm birth, family history of preterm births and prelabour rupture of membranes were independent risk factors for preterm birth. Adolescence, pregnancy weight gain and prenatal consultations, on the other hand, were protective factors for preterm birth. Although the prevalence of premature births in this study was 25%, this could have been biased.

The Simple View of Reading (SVR) proposes that reading comprehension depends on two general processes –language comprehension and word recognition– and that the contribution of these known processes to reading comprehension varies in time. Specifically, the contribution of word recognition decreases, and the contribution of language comprehension increases with student progress. The purpose of this study was to test the SVR in a large sample of 4,750 Dominican public-school students from second (n = 2,399) and fourth grade (2,351) and determine the contribution of phonological awareness within the SVR. The study found that word recognition and language comprehension explained 80% of the variance in reading comprehension regardless of grade. A quantile regression showed that, as reading comprehension progresses, language comprehension’s predictive power increases, and word recognition’s predictive power decreases. A structural equation model conducted on each grade separately showed that the contribution of word recognition toward reading comprehension remained stable between second and fourth grade. This means that, although the dynamism of the SVR components follows the same pattern reported in the literature, the students evaluated here might reach reading automaticity later than expected. Therefore, more attentional resources need to be allocated toward decoding. The study found that the contribution of phonological awareness toward word recognition increases from second to fourth grade, confirming that students are taking longer than expected to obtain reading automaticity and still going through an overt effortful decoding stage rather than a covert phonological recoding stage, making reading more effortful.