Objective Preheated resins (PR) are considered a cementing agent option for indirect adhesive restorations of composite inlays and onlays. The objective of this in vitro study was to evaluate the marginal sealing, adhesive interface, and microtensile bond strength of indirect adhesive restorations of composites in terms of dentin cemented with PR. Materials and Methods Standardized Class II preparations were performed on 30 extracted human premolars, impressions were taken, and indirect composite restorations were manufactured. In total, 15 restorations were cemented with PR (ENA HRi, SYNCA), and 15 restorations were cemented with self-adhesive resinous cement (RC) (Relyx U200, 3M ESPE), followed by a thermocycling regime. After that, these were segmented sagittally and longitudinally to evaluate the marginal sealing and the adhesive interface with scanning electron microscopy and confocal microscopy. Microtensile bond strength was assessed with a mechanical device (TA. XT Plus C, Stable Micro System). Statistical analysis Statistical analysis was conducted using the two-sample Student’s t-test. Results The results showed that there is no statistically significant difference in the degree of microfiltration using PR or RC; however, microtensile bond strength is greater when the restoration is cemented with RC (278.75 N/cm3) than with PR (144.49 N/cm3), and better adjustment and sealing were observed for composite restorations with PR. Conclusion PR comprise an alternative cementing agent for indirect composite restorations in Class II cavities in premolars.

Objective: The aim of this study was to evaluate the frequency of Staphylococcus aureus, Pseudomonas aeruginosa, and Candida species in removable orthodontic appliances (ROA) and the support oral mucosa in children. Study design: The study participants comprised 55 patients aged 6–12 years requiring ROA. The samples of biofilm colonization from the support oral mucosa and the ROA were taken prior to the use of the ROA (T0) and 4 weeks (T1) after ROA placement. The biofilm samples were seeded on chromogenic culture plates and incubated for 24–48 h. Results: The microbial species evaluated were not present in either the support oral mucosa nor in the ROA at T0. After 4 weeks, P. aeruginosa was found in the support oral mucosa with a frequency of 60%, Candida spp. with 30.9% and S. aureus with 89.09%; in the ROA, P. aeruginosa with 67.7%, Candida spp. with 32.7%, while S. aureus with 90.9%. In the ROA were found C. glabrata in 15 cases, C. albicans in 14 cases, C. tropicalis in two cases, and C. krusei in one case. In the oral mucosa there were 10 cases of C. glabrata, 14 cases of C. albicans, one case of C. tropicalis, and 0 cases of C. krusei. Conclusions: The frequency of S. aureus, P. aeruginosa, and Candida spp. increased after the orthodontic treatment in either the ROA and or in the support oral mucosa. There is a direct relation between the use of the ROA and the increase of periodontal-pathogenic microorganisms.

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<p><strong>Introducción:</strong> La práctica odontológica es considerada una profesión de alto riesgo, al estar en contacto directo con fluidos como saliva, secreciones y sangre, los estudiantes y profesionistas deben de estar preparados y contar con los conocimientos para saber actuar ante una pandemia como por el SARS-Cov-2. <strong>Objetivo:</strong> El objetivo de este estudio transversal, descriptivo y exploratorio fue evaluar si existe relación entre la experiencia profesional, la percepción y el nivel conocimiento de COVID-19 con el riesgo de infección. La población estudiada fue de estudiantes de licenciatura, posgrado de Odontología, y profesionistas de practica privada y/o pública. <strong>Métodos:</strong> El instrumento aplicado fue un cuestionario de 35 preguntas de opción múltiple, dividido en tres secciones: 1) variables sociodemográficas, 2) percepción del riesgo a contagiarse con el virus SARS-CoV-2 y enfermar de la COVID-19 y 3) conocimientos respecto a tres aspectos distintos: a) etiopatogenia, b) reconocimiento de las características clínicas o diagnóstico precoz de la COVID-19 y c) pruebas diagnósticas de la COVID-19 (23 preguntas). <strong>Resultados:</strong> Se encuestaron a 847 sujetos, de estos 723 fueron estudiantes de Odontología y 124 dentistas. El porcentaje de positividad de COVID-19 confirmada en los estudiantes fue del 6.8% y un 31.5% de casos de sospecha; en los dentistas un 12.2% de positividad confirmada y un 17.7% de sospecha. Tanto estudiantes y dentistas percibieron que su nivel de conocimiento del COVID-19 es suficiente, perciben que durante su la practica clínica tienen un riesgo alto de ser infectados por el SARS-CoV-2, sin embargo, nuestros resultados señalan que tener menor experiencia profesional ha sido determinante en el aumento del riesgo de contagio de la COVID-19. <strong>Conclusiones:</strong> Los estudiantes de odontología de licenciatura y posgrado, así como los dentistas deben de incluir protocolos en su practica diaria para la detección oportuna de pacientes con COVID-19.</p>