Objectives: The aim of this study was to identify changes in the oral environment with clinical, salivary and bacterial risk markers after placement of fixed orthodontic appliances on permanent dentition. Material and Methods: With ethical approval, we used different techniques to analyzed clinical, salivary and bacterial risk markers in 34 patients (mean age, 16.7 ± 5.2 years), 14 males and 20 females; before starting orthodontic treatment and 1 month after. Clinical risk markers (decayed, missing, and filled surfaces [DMFS], O'Leary´s plaque index, and plaque pH); salivary markers (unstimulated and stimulated saliva flow rate, buffer capacity, pH, and occult blood in saliva) and bacterial counts (Streptococcus mutans and Lactobacillus). Data were analyzed by paired t-test and χ 2 test. Results: This study showed that orthodontic appliances increased the stimulated salivary flow rate (p=0.0001), buffer capacity (p=0.0359), salivary pH (p=0.0246) and occult blood in saliva (p=0.0305). Bacterial levels increased slightly after 1 month of treatment, without statistical significance. Between genders, initially we observed differences in: stimulated saliva (p=0.0019), buffer capacity (p=0.0381) and plaque pH (p=0.0430); after treatment the unstimulated saliva (p=0.0026) showed differences. Conclusions: Orthodontic treatment changes the oral environmental factors, promotes an increase in stimulated flow rate, buffer capacity and salivary pH, which augment the anti caries activity of saliva. In contrast, increased occult blood indicated more gingival inflammation, apparently because augmented the retentive plaque surfaces and the difficult to maintain a good oral hygiene, rinsed the bleeding in saliva by periodontal damage.

In the present study, silver nanoparticles (AgNPs) were synthesized in situ on orthodontic elastomeric modules (OEM) using silver nitrate salts as metal-ion precursors and extract of the plant Hetheroteca inuloides (H. inuloides) as bioreductant via a simple and eco-friendly method. The synthesized AgNPs were characterized by UV-visible spectroscopy; scanning electron microscopy-energy-dispersive spectroscopy (SEM-EDS) and transmission electron microscopy (TEM). The surface plasmon resonance peak found at 472 nm confirmed the formation of AgNPs. SEM and TEM images reveal that the particles are quasi-spherical. The EDS analysis of the AgNPs confirmed the presence of elemental silver. The antibacterial properties of OEM with AgNPs were evaluated against the clinical isolates Streptococcus mutans, Lactobacillus casei, Staphylococcus aureus and Escherichia coli using agar diffusion tests. The physical properties were evaluated by a universal testing machine. OEM with AgNPs had shown inhibition halos for all microorganisms in comparison with OEM control. Physical properties increased with respect to the control group. The results suggest the potential of the material to combat dental biofilm and in turn decrease the incidence of demineralization in dental enamel, ensuring their performance in patients with orthodontic treatment.

Objective To identify dental pain prevalence and associated factors in Mexican schoolchildren. Methods This cross-sectional study included 1,404 schoolchildren aged 6 to 12 years from public schools in the city of Pachuca de Soto, Hidalgo, Mexico. Data were collected through a questionnaire that addressed sociodemographic and socioeconomic factors, eating and dental hygiene habits, and behavior variables. The dependent variable was self-reported dental pain in the 12 months prior to the survey. Data were analyzed using nonparametric statistics and a binary logistical regression model. Results Dental pain prevalence among the studied children was 49.9%. The variables associated in the final model (p < 0.05) were younger mother's age, higher socioeconomic level, absence of an automobile in the home, fried food, fruit intake, lower tooth brushing frequency, never having used mouthwash or not knowing about it, and parents/guardians with regular to high levels of knowledge about oral health and a regular or good/very good perception of their child's oral health. Conclusions One in two children in the study had experienced dental pain in the twelve months prior to the survey. The association of socioeconomic variables with dental pain suggested inequalities among the children in terms of oral health.

To evaluate the relationship between the Human Development Index (HDI) and its components with oral cancer (OC) in Latin America. Ecological study in 20 Latin American countries in 2010 and 2017, which evaluated the relationship between the Age-Standardized Rates (ASRs) of incidence and mortality from oral cancer and the following indicators: HDI, with its components (income, education, and health indexes); and the Gini and Theil-L indexes. Among the countries with the highest HDI, men from Brazil and Cuba had the highest incidence and mortality ASRs per 100,000 inhabitants (ASR incidence >7.5 and mortality >4.5). Among those with the lowest HDI, Haiti was the most affected country (ASR incidence >4.1 and mortality >3.0). The highest male:female ratio was in Paraguay in both years (incidence >3.5 and mortality >4.0). Mortality from oral cancer is negatively related to the global HDI in both years, with regression coefficients (95% confidence interval) being −5.78 (−11.77, 0.20) in 2010 and −5.97 (−11.38, −0.56) in 2017; and separate (independent) from the income [−4.57 (−9.92, 0.77) in 2010 and −4.84 (−9.52, −0.17) in 2017] and health indexes [−5.81 (−11.10, −0.52) and −6.52 (−11.32, −1.72) in 2017] (p < 0.05) in the countries with lower HDI. Oral cancer incidence and mortality rates vary both among and within Latin American countries according to sex, with a greater burden on men. The HDI is negatively related to mortality from oral cancer in the countries of medium and low HDI.

Objetivos: Describir las tendencias de la incidencia del cáncer oral según sexos en Americalatina entre 2000 y 2017; y analizar su relación con factores de riesgo. Método: estudio ecológico que describe las tasas y tendencias de incidencia de cáncer oral en Americalatina; y su correlación con el hábito de fumar, consumo de alcohol y urbanización. Resultados:Las tasas más altas se presentan en los hombres (8,01), y mujeres (3,64) de Cuba. Las tendencias son al aumento, sólo Guatemala presenta estancamiento en ambos sexos. Existe correlación positiva entre la incidencia de cáncer oral y el hábito de fumar (r: 0,37), y con el consumo de alcohol (r: 0,60) en los hombres; y negativa con la urbanización en ambos sexos (r: -0,16) (p:<0,01). Conclusión: La incidencia varía entre los países y entre los sexos, con tendencia al aumento. La mayor carga está en los hombres, con correlación con los factores de riesgo.