Effect of Polywave and Monowave Light Curing Units on the Microtensile Bond Strength and Failure Types of Different Bulk-Fill Resin Composites: An in vitro Study.

Aim: This study aimed to evaluate the effects of polywave and monowave light-emitting diode curing units on the microtensile bond strength and failure types of three bulk-fill resin composites. Materials and Methods: This in vitro experimental study was performed on 180 microbars obtained from human third molars and were distributed into 12 groups according to the type of bulk-fill resin composite and the light-curing unit. Third molars were restored using Filtek One Bulk Fill Restorative, Tetric® N-Ceram Bulk Fill, and Opus Bulk Fill resin composites was light-cured with Elipar Deep Cure L and Valo in three modes: standard, high power, and extra power. Subsequently, microtensile analysis was carried out with a universal testing machine and the type of failure with an optical stereomicroscope. For statistical analysis, the Kruskal-Wallis H-test was used, with the Bonferroni post hoc test and Fisher's exact test, considering a significance of p<0.05. Results: There were significant differences in the microtensile bond strength between the Filtek One Bulk Fill restorative and Opus Bulk-Fill (p = 0.042) when light was cured with the polywave unit at standard power. On the other hand, the Filtek One Bulk Fill Restorative and Opus Bulk Fill resins showed significant differences in microtensile bond strength when light was cured with the monowave unit compared with the polywave unit (p<0.05). Conclusion: The presence of alternative photoinitiator systems that are more reactive than camphorquinone produced higher microtensile bond strength in Tetric N-Ceram Bulk Fill and Opus Bulk Fill resins when light-cured with a high and standard polywave unit, respectively, compared to Filtek One Bulk Fill resins. Finally, Tetric N-Ceram Bulk Fill and Opus Bulk Fill resins had the highest percentage of mixed failures, while Filtek One Bulk Fill resin had adhesive failures, which was related to its lower microtensile bond strength.

In vitro bacterial adherence on teeth submitted to whitening with musa paradisiaca / Adherencia bacteriana in vitro en dientes sometidos a blanqueamiento con musa paradisiaca

Objetive: To compare in vitro bacterial adherence on teeth submitted to whitening with 50% ethanolic extract of Musa paradisiaca and 35% hydrogen peroxide. Material and Methods: The study was experimental and used 18 premolars that were grouped into: G1 (control), G2 (50% ethanol extract of Musa paradisiaca) and G3 (35% hydrogen peroxide). The teeth were then exposed to a Streptococcus mutans culture for 24 hours, followed by centrifugation in thioglycolate broth. A culture on trypticase soy agar was done with a 1 in 100 dilution, and after 48 hours colony forming units (CFU) were counted. Statistical analysis was performed using the ANOVA test, complemented by the Bonferroni post-hoc. Results: Bacterial adherence was 77x105 CFU/ml in Group 3 using 35% hydrogen peroxide, 40x105 CFU/ml in Group 2 using 50% ethanol extract of Musa paradisiaca, and 89x104 CFU/ml in Group 1 (control). The difference between the three groups was significant (p=0.000). Conclusion: Both whitening methods cause bacterial adherence to the tooth surface, although to a lower degree with Musa paradisiaca.eses.

Objetivo: Comparar la adherencia bacteriana in vitro en dientes sometidos a blanqueamiento con extracto etanólico de Musa paradisiaca al 50% y con peróxido de hidrógeno al 35%. Material y Métodos: Comparar la adherencia bacteriana in vitro en dientes sometidos a blanqueamiento con extracto etanólico de Musa paradisiaca al 50% y con peróxido de hidrógeno al 35%.Resultados: La adherencia bacteriana fue de 77x105 UFC/ml con el peróxido de hidrógeno al 35%, de 40x105 UFC/ml con el extracto etanólico de Musa paradisiaca al 50% y de 89x104 UFC/ml con el control. La diferencia fue significativa entre los tres grupos (p=0.000). Conclusión: Ambos métodos de blanqueamiento causan adherencia bacteriana en la superficie dental, siendo menor con Musa paradisiaca.

Depression, anxiety, and stress in dentists in times of covid-19 in northern Peru / Depresión, ansiedad y estrés en cirujanos dentistas en tiempos de covid-19 en el norte del Perú

Objective: To determine the levels of depression, anxiety, and stress in dentists working in the northern region of Peru in times of COV ID -19. Material and Methods: 310 dentists working in the northern region of Peru in times of COVID-19 were evaluated by means of an observational and cross-sectional study. Subjects were asked to give their informed consent and answer a virtual questionnaire containing 21 items based on the DASS-21 Scale that assesses depression, anxiety, and stress. A descriptive analysis was carried out with frequencies; for the variables of gender and years of work experience the Chi square test (p<0.05) was used. Results: It was found that 291 (93.87%) of the dentists suffered from some type of psychological disorder: stress (35.74%), anxiety (35.05%), depression (29.21%). Mild stress was the most prevalent accounting for 49.04% (51); mild depression with 45.88% (39), and moderate anxiety with 40.20% (41). A higher prevalence was found in females and in those dentists who had less than 5 years of work experience. Conclusion: 93.87% of dentists working in the northern region of Peru in times of COVID-19 presented some type of psychological disorder, a higher frequency of mild stress was found, followed by mild depression, and moderate anxiety.

Objetivo: Determinar los niveles de depresión, ansiedad y estrés en cirujanos dentistas que laboran en la región norte del Perú en tiempos de COVID-19. Material y Métodos: Se realizó un estudio observacional de corte transversal, evaluando a 310 cirujanos dentistas que laboran en la región norte del Perú en tiempos de COVID-19 y que respondieron un cuestionario virtual sobre la base de la Escala de Dass-21 que evalúa depresión, ansiedad y estrés y que contiene 21 ítems, previo consentimiento informado. Se realizó un análisis descriptivo con frecuencias y para las variables género y tiempo de servicio se empleó la Prueba Chi cuadrado (p<0.05). Resultados: Se encontró que 291 (93.87%) de cirujanos dentistas presentaron algún trastorno psicológico, de los cuales el 35.74% presentaron estrés; ansiedad el 35.05% o depresión el 29.21%; siendo mayor el estrés leve con el 49.04% (51); depresión leve el 45.88% (39) y ansiedad moderada el 40.20% (41), presentando un porcentaje mayor en mujeres y en aquellos cirujanos dentistas que laboran menos de 5 años. Conclusión: El 93.87% de los cirujanos dentistas que laboran en la región norte del Perú en tiempos de COVID-19, presentaron algún tipo de trastorno psicológico, se encontró mayor frecuencia de estrés leve, seguido de depresión leve y ansiedad moderada.