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This study aims to determine the impact of the COVID-19 pandemic, specifically considering the mandatory social isolation measures implemented, on the perceived stress of a sample of dentists and dental students from Latin America and the Caribbean, as well as the associated sociodemographic and pandemic-related variables. A cross-sectional survey was conducted with a sample of 2036 dentists and dental students (1433 women). For the main outcome, the 14-item Perceived Stress Scale (PSS-14) was used. The survey also questioned sociodemographic aspects, questions on the COVID-19 pandemic, health variables, and habits. Descriptive, bivariate, and multivariate analyses (linear regression) were applied to observe the factors associated with perceived stress. The PSS-14 mean score was 24.76 (±11.76). Hierarchical regression models showed significant variables associated with the PSS-14 scores: income level during mandatory social isolation, having older adults under care during mandatory social isolation, self-perceived level of concern regarding COVID-19, self-perceived health, Coffee consumption during mandatory social isolation. In general terms, the pandemic has influenced the personal, social, labor, and everyday life of dental staff and affected the mental health of this population specifically when perceived stress is considered. Public policies, strategies, and mental health surveillance systems are required for this population.

Objective: To compare the effectiveness of the pretreatment with sandblasting and deproteinization with NaOCl on bond strength (SBS), in situ conversion degree (CD) of brackets in fluorotic enamel, and enamel etching pattern. Methods: A total of 90 non-carious maxillary premolars were used. The teeth were then assigned to six experimental groups according to: enamel surface (sound and fluorotic enamel); surface treatment (Regular etch with 37% phosphoric acid [RE]; 5.2% sodium hypochlorite + phosphoric acid [NaOCl + RE]; sandblasting + phosphoric acid [sandblasting + RE]). After storage in distilled water (37°C/24h), the specimens were tested at 1 mm/min until failure (SBS). Enamel-resin cement interfaces were evaluated for CD using micro-Raman spectroscopy. The enamel-etching pattern was evaluated under a scanning electron microscope. Data from SBS and in situ CD values were analyzed using ANOVA two-away and Tukey test (α=0.05). The enamel etching pattern was evaluated only qualitatively. Results: For sound enamel, RE showed the highest SBS values, when compared to NaOCl + RE and Sandblasting + RE groups (p< 0.01). Regarding CD, only NaOCl + RE significantly compromised the mean DC, in comparison with other groups (p= 0.002). For fluorotic enamel, the Sandblasting + RE group significantly increased the mean SBS values, in comparison with RE group (p= 0.01) and no significant change was observed for CD (p> 0.52). Conclusions: The application of NaOCl or sandblasting associated to phosphoric acid improved the SBS of the brackets in fluorotic enamel without compromising the CD of the resin cement, with improving of enamel interprismatic conditioning.

BackgroundBleaching procedures performed before restorative procedures, due to the oxygen released, affects the quality of bonding restorations. The application of an lower-concentrated antioxidant for one-hour or more can reversal the compromised bonding to bleached enamel, but it was not effective according to the bleaching concentrations applied. The aim of the present study was to evaluate simplified protocol of higher-concentrated sodium ascorbate (35%SA) in bond strength values of enamel bleached with 10%, 16%, 22% carbamide peroxide (CP) or 35% hydrogen peroxide (HP).Material and MethodsThree hundred and forty enamel surfaces of 85 human third molars were used, divided into 17 groups (n=20), according to the following groups: control = no bleaching and no ascorbic acid application; bleaching (CP10%, CP16%, CP22% at-home and HP 35% in-office) and 35%SA application (no application; 35%SA applied twice for 1-min each [SA2×1], twice for 5-min each [SA2×5] and; twice for 10-min each [SA2×10]). After that, adhesive was applied and composite cylinders were made with Filtek Z350 composite. Microshear test was performed in a universal testing machine. BS values were statistically evaluated using ANOVA and Tukey’s and Dunnet’s (against control) tests, with 5% level of significance.ResultsAll bleaching concentrations significantly decrease the enamel bond strength results when compared to control group (p<0.05). More concentrated PC (PC22% and PH35%) showed lower enamel bond strength results when compared to lower concentrated PC (PC10% and PC16%; p<0.05). A significant increase of the enamel bond strength results were only observed when SA2×5 and SA2×10 were applied (p<0.05).ConclusionsThe application of 35% sodium ascorbate for twice 5- and 10-min each was an efficient protocol to reverse the bond strength in bleached enamel at the same level as the no bleaching enamel, independently of the bleaching concentration used. Key words:Tooth bleaching, hydrogen peroxide, sodium ascorbate, bond strength.

Background: To determine the prevalence of dental fluorosis in 10-12 year-old school children, in three provinces of the inter-andean Region of Ecuador: Imbabura, Pichincha and Chimborazo, as well as the relationship between certain factors, considering that the latest studies go back to the year 2009. Material and Methods: A cross-sectional and observational study was proposed. A sample of 599 was calculated at 95% of confidence considering population projections for children between 10 and 12 old of three zones of Ecuador. However, 608 school children, who had the acceptance and informed consent of their parents to participate, completed a survey about factors associated with dental fluorosis. Once the survey was completed, the vestibular surfaces of the upper and lower anterior teeth of the infant were photographed, following standardized distance and light procedures. Three evaluators, trained in the detection of fluorosis using the Thylstrup and Fejerskov index, analyzed the photographs. The Stata 13.0 software was used for the statistical analysis, with a level of significance of 5% and with a confidence interval of 95%. To relate the risk factor of fluorosis, a multinomial logistic model was used. Results: The prevalence of dental fluorosis was of 89.96%, with a greater presence of grade 2 TF. A positive statistical relationship and statistical significance was detected between dental fluorosis and consumption of bottled beverages. Also the amount of toothpaste used and its ingestion during brushing (p = 0.000) were analyzed. Conclusions: The populations evaluated, that are related to the consumption of bottled beverages and involuntary toothpaste ingestion, and have a high prevalence of a mild level of fluorosis.