Comparative Evaluation of Microtensile Bond Strength in Three Different Dentin Luting Agents: An In vitro Study.

Aim: Long-term clinical success on indirect restorations is largely determined by bonding efficiency of the luting agent, with adhesion to dentin being the main challenge. Therefore, aim of this study was to assess the microtensile bond strength when using flowable resin composite, preheated resin composite and dual self-adhesive resin cement as dentin luting agents. Materials and Methods: Occlusal thirds of molar teeth were cut and randomly divided into 3 groups to be cemented: RelyX™U200, Filtek™ Z250 XT- preheated to 70° and Filtek Flow™ Z350XT. They were then thermocycled 5000 times between 5+/-2°C and 55+/-2°C. Subsequently, 10 microbars per group were prepared. The 30 samples were placed in saline solution for 24 hours at room temperature prior to microtensile test. This was performed with a digital universal testing machine at a crosshead speed of 0.5 mm/min. The bond strength values obtained were analyzed in Megapascals (MPa). Measures of central tendency such mean and measures of dispersion such standard deviation were used. In addition, the Kruskall Wallis non-parametric test with Bonferroni post hoc test was applied, considering a significance value of 5% (P < 0.05), with type I error. Results: The dentin microtensile bond strengths of preheated resin composite, flowable resin composite and dual self-adhesive cement were 6.08 ± 0.66 Mpa, 5.25 ± 2.60Mpa and 2.82 ± 1.26Mpa, respectively. In addition, the preheated resin composite exhibited significantly higher microtensile bond strength compared to the dual self-adhesive cement (P < 0.001). While the flowable resin composite showed no significant difference with the dual self-adhesive cement (P = 0.054) and the preheated resin composite (P = 0.329). Conclusions: The microtensile bond strength in dentin was significantly higher when using a preheated resin composite at 70°C as a luting agent compared to dual self-adhesive cement. However, the preheated resin composite showed similar microtensile bond strength compared to the flowable resin composite.

Resonance Frequency Analysis Mapping During Implant Healing Using a Nanostructured Hydroxyapatite Surface.

Aim: Stability measured by resonance frequency analysis (RFA) is an important factor to be considered in the success of dental implant treatments, which can be evaluated from the implant stability quotient (ISQ). The aim of the present case series was to map the RFA during healing of implants with nanostructured hydroxyapatite surface to describe the behavior of ISQ values related to individual factors. Materials and Methods: Twenty-three implants were placed in eight patients by conventional surgical protocol, and ISQ values were monitored from the day of implant placement until week 20. To obtain the ISQ values, an Osstell device was used and the placed implants were grouped in proportional amounts to describe the ISQ behavior considering the length (≤10 or >10 mm), the diameter (3.5 or 4.3 mm), the insertion torque (<40 N-cm or ≥40 N-cm), and the placement area (maxilla or mandible). Results: All the implants assessed decreased their values in the first 3 weeks after placement. Subsequently, the ISQ values increased by amounts similar to those obtained at the time of the placement and even more. Implants with length >10 mm, diameter 4.3 mm, and insertion torque ≥40 N-cm showed the highest ISQ values. Conclusions: A decrease in the ISQ values of dental implants with nanostructured hydroxyapatite surface was evidenced between weeks 2 and 3 considering length, diameter, insertion torque, and maxillary or mandibular placement site.

Factors associated with the perception of university professors about academic dishonesty in dental students from two peruvian universities: analysis under multivariable regression model.

BACKGROUND: Academic dishonesty is an intentional behavior that transgresses ethics in the teaching-learning process. The present study aimed to evaluate the factors associated with the perception of university professors about academic dishonesty in dental students from two universities in the Peruvian capital. METHODS: This cross-sectional, analytical study evaluated 181 professors from two Peruvian universities between March and July 2022. A validated 28-item questionnaire was used to measure the perceived academic dishonesty of their students. A logit model was used to evaluate the influence of the variables gender, marital status, place of origin, academic degree, specialization, academic area, years of teaching experience, scientific publications, ethical training and university of origin, considering a significance level of p < 0.05. RESULTS: According to the median, professors perceived that their students sometimes had attitudes and motivations to commit academic dishonesty. The professors whose origin was the capital city were twice as likely to perceive dishonest attitudes in dental students as those whose origin was a province (OR = 2.04; 95% CI: 1.06-3.93). University professors in pre-clinical courses were 0.37 times less likely to perceive dishonest attitudes than those teaching in the dental clinic (OR = 0.37; CI: 0.15-0.91). University professors in basic science courses and professors in preclinical courses were 0.43 times (OR = 0.43; CI: 0.19-0.96) and 0.39 times (OR = 0.39; CI: 0.15-0.98) less likely to perceive dishonest motivations in their students compared to university professors in the dental clinic. Gender, marital status, academic degree, specialty, years of teaching experience, scientific publications and ethical training were not found to be influential factors (p > 0.05). CONCLUSION: Although all university professors surveyed perceived dishonest attitudes and motivations in their students, university professors from the capital city perceived such attitudes more. In addition, being a preclinical university professor was a hindered factor for perceiving such dishonest attitudes and motivations. It is advisable to implement and constantly disseminate regulations that empower academic integrity as well as to manage a system for reporting misconduct and to make students aware of the impact of dishonesty in their professional training.

Surface Roughness in Nanoparticle Resin Composites Subjected to Two Polishing Systems: An In vitro Comparative Study.

Aim: The surface roughness of dental restorations can decrease resin durability, since it leads to its deterioration, color variation, and loss of gloss. Therefore, the aim was to assess the surface roughness of nanoparticle resin composites, subjected to two different polishing systems. Materials and Methods: This longitudinal in vitro experimental study consisted of 32 resin specimens made according to ISO 4049-2019 and divided equally into four groups: A1: Palfique LX5 / Sof-Lex, A2: Palfique LX5 / Super Snap, B1: Filtek Z350 XT / Sof-Lex, and B2: Filtek Z350 XT / Super Snap. The samples were stored in distilled water at 37°C for 24 h. Surface roughness was measured with a digital roughness tester, both before and after the polishing procedure. The data were analyzed with the Student's t-test for related samples, and with the inter-subject ANOVA test with two factors; considering significance at P < 0.05. Results: The surface roughness of Palfique LX5 resin with the Sof-lex system was 0.330 (CI: 0.282-0.378 µm) and 0.170 (CI: 0.087-0.253 µm) before and after polishing, respectively. With the Super Snap system, values of 0.448 (CI: 0.346-0.549 µm) and 0.206 (CI: 0.130-0.282 µm) were obtained before and after polishing, respectively. For the Filtek Z350 XT resin, the surface roughness obtained with the Sof-lex system was 0.353 (CI: 0.278-0.427 µm) and 0.134 (CI: 0.095-0.172 µm) before and after polishing, respectively. With the Super Snap system, values of 0.334 (CI: 0.247-0.421 µm) and 0.171 (CI: 0.122-0.221 µm) were obtained before and after polishing, respectively. Surface roughness did not show significant differences in all groups assessed both before (P = 0.068) and after (P = 0.335) polishing. However, before and after the application of the polishing systems, all groups significantly decreased their surface roughness (P < 0.05). Further, when comparing this decrease among all groups, no significant differences were observed (P = 0.437). Conclusion: The surface roughness of the Filtek Z350 XT and Palfique LX5 nanoparticle resin composites showed no significant differences when using the Sof-lex and Super Snap polishing systems. However, both polishing systems significantly decreased the surface roughness of the nanoparticulated resins, with this decrease being similar in all groups.

The Microhardness and Surface Roughness Assessment of Bulk-Fill Resin Composites Treated with and without the Application of an Oxygen-Inhibited Layer and a Polishing System: An In Vitro Study.

The aim of this study was to assess the microhardness and surface roughness of bulk-fill resin composites treated with and without the application of an oxygen-inhibited layer (OIL) and a polishing system. This in vitro experimental study consisted of 72 resin composite blocks divided into three groups: Tetric N-Ceram Bulk Fill, Opus Bulk Fill APS, and Filtek Bulk Fill. Each resin composite group was further divided into two subgroups: with and without OIL control. Subsequently, surface roughness and microhardness were measured before and after polishing. A t-test was used to compare independent and related measures. For the intergroup comparison of variation before and after polishing, the Kruskal−Wallis test with Bonferroni post hoc was used considering a significance level of p < 0.05. When comparing surface roughness, significant differences were observed between Opus Bulk Fill resin composite with and without OIL control (p = 0.003) before polishing. The same occurred when comparing Tetric N-Ceram resin composite with and without OIL control (p = 0.039) after polishing. In addition, the surface roughness of Filtek Bulk Fill, Opus Bulk Fill, and Tetric N-Ceram Bulk Fill resin composites, with and without OIL control, decreased significantly after polishing (p < 0.001), while surface microhardness significantly increased (p < 0.05), with the exception of Opus Bulk Fill resin with OIL control (p = 0.413). In conclusion, OIL control and polishing significantly improved the surface roughness and surface microhardness of Filtek Bulk Fill and Tetric N-Ceram Bulk Fill resin composites. However, in the case of Opus Bulk Fill resin composite, only its surface roughness was significantly improved.

Impact of Puppet Theater on Oral Health Knowledge and Oral Hygiene in Preschoolers from a Peruvian Educational Institution: A Quasi-experimental Study.

Aim: The puppet theater, due to its artistic and educational characteristics, could allow children to develop oral health self-care in an attractive and fun way. The aim of this study was to evaluate the impact of puppet theater on oral health knowledge and oral hygiene in preschoolers from a Peruvian public school. Materials and Methods: An analytical, longitudinal, and quasi-experimental study was conducted in 132 preschoolers divided into three age-matched groups (3, 4, and 5 years old) from August to November 2019 in a Peruvian public school. At 4 weeks and 4 months after performing the puppet theater, a validated questionnaire of five closed questions was used to evaluate oral health knowledge, and the Greene-Vermillion index [only bacterial plaque index (BPI) part] was used to evaluate oral hygiene, considering good (0-0.6), fair (0.7-1.8), and poor (1.9-3.0). The theater sessions were held every week for the first month and every 2 weeks for the following 3 months. To analyze the levels in the BPI, the Wilcoxon and Friedman test was used to compare related measures, and to compare the knowledge for each question of the questionnaire, the McNemar and Cochran's Q tests were used, considering a P-value less than 0.05. Results: The BPI in relation to age (3, 4, and 5 years), before and after 4 months of performing the puppet theater, was 1.9 [confidence interval (CI): 1.7-2.0], 1.8 (CI: 1.6-1.9), and 1.8 (CI: 1.7-2.0), decreasing to 0.9 (CI: 0.8-1.0), 0.8 (CI: 0.7-0.9), and 0.9 (CI: 0.8-1.00), respectively. In relation to gender (men and women), it was 1.8 (CI: 1.7-2.0) and 1.8 (CI: 1.7-1.9), decreasing to 0.9 (CI: 0.8-1.0) and 0.8 (CI: 0.8-0.9), respectively. In relation to origin (urban or rural), it was 1.8 (CI: 1.7-1.9) and 1.8 (CI: 1.4-2.2), decreasing to 0.9 (CI: 0.8-0.9) and 0.8 (CI: 0.7-0.9), respectively. The level of BPI and oral health knowledge improved significantly (P < 0.001) over time in all preschoolers, except in those who came from the rural area (P > 0.05). Conclusion: The application of the puppet theater positively influenced the preschoolers in such a way that it significantly improved their oral health knowledge and oral hygiene at 4 weeks and 4 months, in both genders of 3, 4, and 5 years of age, and in those whose origin was the urban area. However, no significant improvements in oral health knowledge and oral hygiene were observed in those preschoolers whose origin was the rural area.

Eficacia Antimicrobiana del Cemento Portland Comparado con el Mineral Trióxido Agregado Frente a Enterococcus faecalis y Candida albicans

RESUMEN: El objetivo del estudio experimental in vitro fue evaluar la eficacia antimicrobiana del cemento Portland (CP) comparado con el Mineral Trióxido Agregado (MTA) frente a cepas de Enterococcus faecalis (E. faecalis) y Candida albicans (C. albicans) a las 24, 48 y 72 horas después del sembrado. Para ello se utilizó la técnica de difusión en agar. La capa base fue realizada con el Agar Müller-Hinton en el que se hicieron agujeros de 6 mm de diámetro a fin de contener los cementos de estudio y medir posteriormente la zona de inhibición microbiana alrededor de los materiales mediante un calibrador vernier digital. Se utilizó la prueba T de Student para comparar la diferencia entre el CP y MTA y el análisis de ANOVA para evaluar las diferencias entre los tres tiempos de estudio. Los resultados mostraron que tanto frente a E. faecalis y C. albicans el CP tuvo un mayor halo de inhibición que el MTA, siendo estas diferencias estadísticamente significativas (p0.05). Asimismo, la C. albicans presentó valores mayores de inhibición que el E. faecalis en los dos cementos estudiados. Se concluyó que el CP tuvo mayor eficacia antimicrobiana que el MTA independientemente del tiempo evaluado.

ABSTRACT: The aim of the experimental in vitro study was to evaluate the antimicrobial efficacy of Portland cement (CP) compared with Mineral Trioxide Aggregate (MTA) against Enterococcus faecalis (E. faecalis) and Candida albicans (C. albicans) strains at 24, 48 and 72 hours after sowing. For this, the agar diffusion technique was used. The base layer was made with Müller-Hinton Agar in which 6 mm diameter holes were made in order to contain the study cements and subsequently measure the zone of microbial inhibition around the materials using a digital vernier caliper. The Student's t test was used to compare the difference between CP and MTA and the ANOVA analysis to evaluate the differences between the three study times. The results showed that both against E. faecalis and C. albicans, CP had a greater inhibition than MTA, these differences being statistically significant (p 0.05). Likewise, C. albicans presented higher inhibition values than E. faecalis in the two cements studied. It was concluded that CP had greater antimicrobial efficacy than MTA regardless of the time evaluated.

Cambios del pH salival por ingesta cariogénica y no cariogénica en preescolares de Huaura, Perú / Salivary pH changes caused by cariogenic and non-cariogenic food intake in preschoolers from Huaura, Peru

Introducción: El tipo de dieta influye directamente en el valor del pH salival, el cual es un factor importante para evitar la formación de caries. Objetivo: Evaluar el cambio del pH salival por ingesta cariogénica y no cariogénica en preescolares de una institución educativa de Huaura, Perú. Métodos: Esta investigación fue de tipo observacional, comparativo y longitudinal. El tamaño de muestra fue de 30 preescolares. Después que los niños consumieron dieta cariogénica y no cariogénica, se evaluó su pH a diferentes tiempos. Para el contraste de resultados se utilizó la prueba T Student y U de Mann-Whitney. Resultados: El pH salival con dieta no cariogénica a los cinco minutos fue 7,11 ± 0,19 y 7,09 ± 0,20, y, a los 40 minutos, 7,46 ± 0,19 y 7,42 ± 0,22, en mujeres y hombres, respectivamente. El pH salival con dieta cariogénica en mujeres fue 6,56 ± 0,21 a los cinco minutos y 7,15 ± 0,12 a los 60 minutos; mientras que, en los hombres, para iguales rangos de tiempos fue 6,47 ± 0,32 y 7,23 ± 0,22, respectivamente. Al realizar las comparaciones entre grupos de dieta cariogénica y no cariogénica se observaron diferencias muy significativas (p < 0,01). Conclusiones: Para la dieta cariogénica el pH disminuye como máximo a los cinco minutos y se restablece a partir de los 60 minutos. Para la dieta no cariogénica disminuye en el mismo tiempo pero se recupera a los 40 minutos, siendo este proceso similar en ambos géneros(AU)

Introduction: Salivary pH, an important factor in caries prevention, is under the direct influence of diet type. Objective: Evaluate salivary pH changes caused by cariogenic and non-cariogenic food intake in preschoolers from an educational institution in Huaura, Peru. Methods: An observational longitudinal comparative study was conducted of a sample of 30 preschoolers. After the children consumed cariogenic and non-cariogenic food, their salivary pH was evaluated at various times. Student's t-test and the Mann-Whitney U test were used to contrast results. Results: Salivary pH with a non-cariogenic diet at five minutes was 7.11 ± 0.19 and 7.09 ± 0.20; whereas at 40 minutes it was 7.46 ± 0.19 and 7.42 ± 0.22, in female and male participants, respectively. Salivary pH with a cariogenic diet in women was 6.56 ± 0.21 at five minutes and 7.15 ± 0.12 at 60 minutes, whereas values in men for the same time ranges were 6.47 ± 0.32 and 7.23 ± 0.22, respectively. Comparison between the cariogenic and non-cariogenic diet groups revealed very significant differences (p < 0.01). Conclusions: With a cariogenic diet, pH is reduced at five minutes maximum, and is restored as of 60 minutes. With a non-cariogenic diet, pH is reduced in the same time period, but is restored at 40 minutes. This process is similar in the two genders(AU)

Knowledge about oral health, salivary PH, body mass index and its relationship with dental caries in preschool children / Conocimiento en salud bucal, PH salival, índice de masa corporal y su relación con caries dental en preescolares

Abstract Introduction: Dental caries is a disease caused by the interaction of several factors, including diet, since the development of the biological environment that promotes cariogenic bacterial metabolism often depends on it. Objectives: To determine the prevalence of caries in preschool children from Huaura, Peru, and to confirm if there is an association between their salivary pH and body mass index (BMI) and the level of knowledge about oral health of one of their parents. Materials and methods: A non-experimental, correlational, and cross-sectional study was conducted in 126 preschoolers equally distributed in 3 age groups (3, 4, and 5 years old). The association between the presence of caries and the variables considered was determined by means of the chi-square test of independence, with a confidence level of 95% and a type I error of 5%. In addition, a multiple logistic regression analysis was performed to calculate the probability of caries development in relation to each risk factor. Results: The prevalence of caries was 80.2% (95%CI:73.2-87.2); furthermore, salivary pH (p=0.012) and the level of parental knowledge (p<0.001) were significantly associated with caries occurrence. Regarding the multiple regression analysis, an OR=0.12 (95%CI:0.02-0.63) was obtained for pH and an OR=0.50 (95%CI:0.35-0.74) for the level of parental knowledge in relation to the probability of caries development. Conclusion: The level of parental knowledge about oral health and high salivary pH levels of preschoolers were protective factors against caries development in the study population. On the other hand, no association was found between BMI and the presence of caries in 5-year-old preschoolers.

Resumen Introducción. La caries dental es una condición causada por la interacción de múltiples factores, entre ellos la dieta, ya que, con frecuencia, de ella depende el desarrollo del medio biológico propicio para el metabolismo bacteriano cariogénico. Objetivo. Determinar la prevalencia de caries en preescolares de Huaura, Perú, y confirmar si hay una asociación con el pH salival y el índice de masa corporal (IMC) de los preescolares, y con el nivel de conocimiento en salud bucal de uno de sus padres. Materiales y métodos. Estudio no experimental, correlacional y transversal realizado en 126 preescolares distribuidos equitativamente en 3 grupos etarios (3, 4 y 5 años). La asociación entre presencia de caries y las variables consideradas se determinó mediante la prueba de independencia de chi cuadrado, con un nivel de confianza del 95% y error tipo I del 5%; además, se realizó un análisis de regresión logística múltiple para calcular la probabilidad de ocurrencia de caries en relación con cada factor de riesgo. Resultados. La prevalencia de caries fue de 80.2% (IC95%:73.2-87.2); además, el pH salival (p=0.012) y el nivel de conocimiento de los padres (p<0.001) se asociaron significativamente con la ocurrencia de caries. En cuanto al análisis de regresión múltiple, se obtuvo un 0R=0.12 (IC95%:0.02-0.63) para el pH y un 0R=0.50 (IC95%:0.35-0.74) para el nivel de conocimiento de los padres en relación con la probabilidad de presentar caries. Conclusión. El nivel de conocimiento sobre salud bucal de los padres y los niveles altos de pH salival de los preescolares fueron factores protectores frente al desarrollo de caries en la población de estudio. Por otra parte, no se encontró asociación entre IMC y presencia de caries en los preescolares de 5 años.

Effect of Polishing on the Surface Microhardness of Nanohybrid Composite Resins Subjected to 35% Hydrogen Peroxide: An In vitro Study.

AIM: The use of bleaching agents, despite being a conservative treatment, can cause a decrease in the surface microhardness of dental resins, affecting their aesthetics and performance. The aim of this study was to evaluate the in vitro effect of polishing on the surface microhardness of nanohybrid composite resins that were subjected to bleaching with 35% hydrogen peroxide. MATERIALS AND METHODS: This cross-sectional, in vitro experimental study consisted of 30 composite resin samples made according to ISO 4049-2019 and divided equally into two groups (A and B) which were subjected to 35% hydrogen peroxide bleaching. Group A was subjected to polishing procedure, whereas group B was the control group. The samples were stored in distilled water at 37°C for 24 h. The Vickers microhardness was determined with a load of 100 g-f for 10 s. The data were analyzed with Student's t-test for independent samples at a confidence level of 95%. RESULTS: The surface microhardness of the group that was subjected to polishing (A) obtained a mean of 78.07 ± 7.96 HV, whereas for the group that was not subjected to polishing (B) the mean was 65.67 ± 5.22 HV. The difference between groups (A and B) was statistically significant (P < 0.001). CONCLUSION: Nanohybrid composite resins previously subjected to 35% hydrogen peroxide gel significantly increased their surface microhardness when subjected to polishing when compared with unpolished nanohybrid composite resins.

Impact of COVID-19 Mandatory Social Isolation on the Development of Anxiety in Peruvian Dentistry Students: A Logistic Regression Analysis.

AIM: The COVID-19 pandemic has generated much concern worldwide. Due to its high transmissibility, many young university students have had to carry out their academic activities in mandatory social isolation, which could generate excessive anxiety. Therefore, the aim of this study was to evaluate the anxiety levels in Peruvian dentistry students developed during COVID-19 mandatory social isolation. MATERIALS AND METHODS: An analytical, observational, and transversal study was carried out in 403 dentistry students in the last two years from three Peruvian universities from May to July 2020. The Zung Self-Rating Anxiety Scale was used to detect anxiety symptoms and their respective diagnoses. A logit model was used to evaluate the association of the variables: age group (X1), gender (X2), type of university (X3), and marital status (X4), with the anxiety levels of the students, considering a p-value less than 0.05. RESULTS: The prevalence of anxiety resulted in 56.8% (95% confidence interval (CI): 51.9-61.7) of 403 dentistry students. According to the multivariate logistic regression analysis, the type of university was the only variable that demonstrated to have a significant influence on the development of anxiety with an odds ratio (OR = 1.98; CI: 1.29-3.02); whereas the other variables such as age group (OR = 0.77; CI: 0.49-1.20), gender (OR = 1.15; CI: 0.72-1.84), and marital status (OR = 0.75; CI: 0.35-1.60) were not considered factors that influenced the development of anxiety. CONCLUSION: More than a half of the Peruvian dentistry students from three universities showed mild-to-severe anxiety levels. Students from a private university have a 98% higher chance of developing anxiety in comparison to students from public universities. Other variables such as gender, age group, or marital status were not considered influencing factors to develop anxiety.

Evaluación antibacteriana del peróxido de hidrógeno comparado con hipoclorito de sodio sobre cepillos dentales inoculados con Streptococcus mutans / Antibacterial Evaluation of Hydrogen Peroxide Compared to Sodium Hypochlorite on Dental Brushes Inoculated with Streptococcus Mutans / Avaliação do efeito antibacteriano do peróxido de hidrogênio em comparação ao hipoclorito de sódio em escovas de dente inoculadas com Streptococcus mutans

Resumen Objetivo: evaluar el efecto antibacteriano del peróxido de hidrógeno (H2O2) al 6 % comparado con hipoclorito de sodio (NaClO) al 1 % y al 2 %, sobre cepillos dentales inoculados con Streptococcus mutans ATCC® 25175™. Materiales y métodos: estudio experimental in vitro, transversal y comparativo. Se utilizaron 60 cepillos dentales, divididos en 4 grupos de 15 cepillos cada uno. El número de muestra lo determinó la fórmula de comparación de medias, después de realizar un estudio piloto, y se seleccionaron por muestreo aleatorio simple. Se aplicaron las pruebas de normalidad de Shapiro-Wilk, y para la prueba de hipótesis, la U de Mann-Whitney. Resultados: el H2O2 al 6 % presentó una media de crecimiento de 2 * 109 UFC/mL, lo que indica que su efectividad es mayor comparada con el NaClO al 1 %>, que presentó una media de crecimiento de 4 * 109 UFC/mL, y esta es menor al NaClO al 2 %, que tuvo 0 UFC /mL de Streptococcus mutans (p = 0,004). Conclusión: el H2O2 al 6 % y el NaClO al 1 % y al 2 % evidenciaron efectividad antibacteriana, aun cuando fue el NaClO al 2 % el más efectivo.

Abstract Objective: To assess the antibacterial effect of 6% hydrogen peroxide (H2O2) compared with 1% and 2% sodium hypochlorite, on toothbrushes inoculated with Streptococcus mutans ATCC® 25175™. Materials and methods: The study design was an experimental in vitro, cross-sectional prospective and comparative study. Sixty toothbrushes were used, which were divided into four groups of 15 brushes. After conducting a pilot study, the sample number was determined by the means comparison formula and these were selected by simple random sampling. These brushes were inoculated with strains of S. mutans ATCC® 25175™. The disinfectants included H2O2 at 6% and sodium hypochlorite (NaOCl) at 1% and 2%. The Shapiro-Wilk test was used to assess normality and the Mann-Whitney U test was applied for the hypothesis test. Results: The 6% H2O2 showed an average growth of 2 * 109 CFU/mL, which indicates that its effectiveness is greater compared to the 1% NaClO that showed a growth average of 4 * 109 CFU/mL which is less than the 2% NaClO that presented 0 CFU/mL of S. mutans (p = 0.004). Conclusion: Between 6% H2O2 and 1% and 2% NaClO, specifically antibacterial detection, 2% NaClO was concluded as being the most effective.

Resumo Objetivo: avaliar o efeito antibacteriano do peróxido de hidrogênio 6% em comparação ao hipoclorito de sódio 1% e 2%, em escovas de dente inoculadas com Streptococcus mutans ATCC® 25175™. Materiais e métodos: estudo experimental in vitro, transversal e comparativo. Foram utilizadas 60 escovas de dente, as quais foram divididas em 4 grupos de 15 escovas cada um. O número amostral foi determinado pela fórmula de comparação de médias, após realização de um estudo piloto, sendo selecionado por meio de amostragem aleatória simples. As escovas foram inoculadas com cepas de Streptococcus mutans ATCC® 25175™. Os desinfetantes utilizados foram peróxido de hidrogênio (H202) 6% em comparação ao hipo-clorito de sódio (NaClO) 1% e 2%. Aplicou-se a prova de normalidade de Shapiro-Wilk e como teste de hipótese utilizou-se o U de Mann-Whitney. Resultados: o H202 6% apresentou uma média de crescimento de 2*109 UFC/mL, indicando uma efetividade maior em comparação com o NaClO 1% que apresentou uma média de crescimento de 4*109 UFC/mL, que por sua vez foi menos efetivo que o NaClO 2% que apresentou uma contagem de 0 UFC/mL de Streptococcus mutans (p=0,004). Conclusão: o H2O2 6% e o NaClO 1% e 2%, apresentaram efetividade antibacteriana, sendo que o NaClO 2% foi totalmente efetivo.

Association Between Periodontal Disease and the Risk of COVID-19 Complications and Mortality: A Systematic Review.

AIM: The COVID-19 pandemic has strained the world's healthcare systems. Studies have identified how the COVID-19 infections are linked to several co-morbidities such as hypertension, diabetes, cardiovascular disease, renal and pulmonary disease. It is known that periodontal disease (PD) shares the same risk factors. Moreover, both diseases are characterized by an exaggerated immune response. The aim of the study was to investigate the available evidence of a potential association between PD and the risk of COVID-19 complications and mortality. MATERIALS AND METHODS: MEDLINE/PubMed, EMBASE, Scopus, and ProQuest were searched. Studies that assess the association between PD and the risk of COVID-19 complications and mortality were eligible for inclusion. Two independent reviewers performed the selection of articles and data extraction. The New Castle Ottawa Scale was used to assess the quality of the selected studies, and the GRADE system was used to evaluate the level of confidence to support the conclusions. RESULTS: Only two studies met the eligibility criteria. One study had a low risk of bias, whereas the other had a high risk of bias. CONCLUSION: The level of confidence in the available evidence is very low. A close association between periodontitis and the risk of COVID-19 complications and mortality can neither be supported nor refuted.

Actividad antibacteriana y antifúngica del aceite esencial de Minthostachys mollis frente a microorganismos de la cavidad oral / Antibacterial and Antifungal Activity of the essential oil of Minthostachys mollis against oral microorganisms

Introducción: La Minthostachys mollises una planta aromática que crece en América Latina y produce aceites esenciales con acción antimicrobiana. Objetivo: Determinar la actividad del aceite esencial de Minthostachys mollis en diferentes concentraciones, comparado con doxiciclina y fluconazol frente a Porphyromonas gingivalis, Staphylococcus aureus y Candida albicans, a las 24, 48 y 72 horas. Métodos: Se realiza estudio experimental in vitro y longitudinal. Se prepararon 15 pocillos por subgrupo para evaluar el efecto inhibitorio de todas las concentraciones, dando un total de 360 pocillos. Por cromatografía de gases acoplada a espectrometría de masas se identificaron los componentes químicos del aceite esencial. Se analizó el efecto inhibitorio por el método de difusión de Kirby-Bauer en Agar Columbia y Agar Muller Hinton. El análisis estadístico se realizó mediante la prueba ANOVA y Tukey. Resultados: En el análisis químico se identificó principalmente pulegona (30,17 por ciento) y mentona (16,55 por ciento). Los halos de inhibición de Minthostachys mollis al 100 por ciento a las 24, 48 y 72 horas frente a la Porphyromonas gingivalis, midieron: 10,2 mm, 9,8 mm y 9,6 mm, respectivamente; frente al Staphylococcus aureus, midieron: 10,4 mm, 9,7 mm y 9,4 mm, respectivamente; y, por último, frente a Candida albicans midieron: 9,8 mm, 8,9 mm y 8,5 mm, respectivamente. Todas las concentraciones de Minthostachys mollis presentaron un efecto antimicrobiano significativamente menor que el fluconazol y la doxiciclina (p < 0,001). Conclusiones: El aceite esencial de Minthostachys mollis al 100 % presentó su mejor actividad inhibitoria frente al Staphylococcus aureus, la Porphyromonas gingivalis y la Candida albicans a las 24 horas. Sin embargo, este efecto antimicrobiano disminuye a medida que pasa el tiempo(AU)

Introduction: Minthostachys mollis is an aromatic plant species growing in Latin America which produces essential oils with antimicrobial activity. Objective: Determine the activity of essential oil from Minthostachys mollis at various concentrations as compared with doxycycline and fluconazole against Porphyromonas gingivalis, Staphylococcus aureus and Candida albicans at 24, 48 and 72 hours. Methods: An in vitro experimental longitudinal study was conducted. Fifteen wells were prepared per subgroup to evaluate the inhibitory effect of all concentrations, for a sum total of 360 wells. Chemical components of the essential oil were identified by gas chromatography-mass spectrometry. The inhibitory effect was analyzed with the Kirby-Bauer diffusion method in Mueller-Hinton and Columbia agar. Statistical analysis was based on ANOVA and Tukey's test. Results: Chemical analysis mainly found pulegone (30.17 percent) and menthone (16.55 percent). The inhibition halos of 100 percent Minthostachys mollis at 24, 48 and 72 hours against Porphyromonas gingivalis measured 10.2 mm, 9.8 mm and 9.6 mm, respectively, against Staphylococcus aureus they measured 10.4 mm, 9.7 mm and 9.4 mm, respectively, and against Candida albicans they measured 9.8 mm, 8.9 mm and 8.5 mm, respectively. The antimicrobial effect of Minthostachys mollis at all concentrations was significantly lower than that of fluconazole and doxycycline (p < 0.001). Conclusions: The essential oil from 100% Minthostachys mollis displayed its best inhibitory activity against Staphylococcus aureus, Porphyromonas gingivalis and Candida albicans at 24 hours. However, such antimicrobial effect decreases with the passing of time(AU)

Sellado marginal aplicando hipoclorito de sodio versus ácido fosfórico como acondicionador dental / Marginal sealing applying sodium hypochlorite versus phosphoric acid as dental conditioner

RESUMEN Introducción: La microfiltración es uno de los problemas principales de todas las obturaciones a base de resina. Muchos estudios buscan optimizar un buen sellado marginal utilizando diversos acondicionadores, como el hipoclorito de sodio, que permite que el adhesivo penetre bien, al generar desproteinización, y el ácido fosfórico que permite remover el barro dentinario, y así de esta manera formar una capa híbrida al colocar el adhesivo. Objetivo: Evaluar el grado de sellado marginal de la resina Bulk Fill aplicando gel de hipoclorito de sodio 10 por ciento comparado con el gel de ácido fosfórico al 37 por ciento en el acondicionamiento dental in vitro. Métodos: El universo fue de 72 dientes con cavidades clase I; se separaron en 4 grupos por muestra de 18 dientes cada uno; después de obturar se realizó el termociclaje a 500 ciclos entre 5 °C a 55 °C; luego se sumergieron en azul de metileno 2 por ciento, durante 12 h y 24 h a temperatura de 37 °C. Finalmente se evaluó el sellado marginal en el estereomicroscopio, según el ISO / TS 11405: 2015, con los criterios siguientes: grado 0 (sin microfiltración), grado 1 (microfiltración hasta esmalte), grado 2 (microfiltración hasta dentina) y grado 3 (microfiltración hasta piso pulpar). Resultados: El acondicionamiento con ácido fosfórico 37 por ciento a las 12 h presentó grado 0 (55,6 por ciento) y grado 1 (33,3 por ciento), y a las 24 h, grado 1 (55,6 por ciento). Con respecto al hipoclorito de sodio 10 por ciento a las 12 h, grado 0 (44.4 por ciento) y a las 24 h predominó grado 1 (55,6 por ciento). Para la contrastación de hipótesis en muestras relacionadas se obtuvo en ácido fosfórico 37 por ciento e hipoclorito de sodio al 10 por ciento a las 12 h y 24 h un p= 0,052 y p= 0,584, respectivamente. Para comparaciones entre muestras independientes a las 12 h y 24 h se obtuvo p= 0,462 y p= 0,406, respectivamente. Conclusiones: El gel de hipoclorito de sodio al 10 por ciento presenta similar eficacia en el sellado marginal respecto al gel de ácido fosfórico al 37 por ciento, al utilizarlo como acondicionador dental(AU)

ABSTRACT Introduction: Microfiltration is one of the main problems of all resin sealings. Many studies aim to optimize marginal sealing using a variety of conditioners, such as sodium hypochlorite, which allows good penetration of the adhesive by generating deproteinization, and phosphoric acid, which allows removal of the dental smear layer, thus creating a hybrid layer when the adhesive is placed. Objective: Evaluate the marginal sealing degree of Bulk Fill resin applying 10 percent sodium hypochlorite gel versus 37 percent phosphoric acid gel in in vitro dental conditioning. Methods: The study universe was 72 teeth with class I cavities, divided into four groups of 18 teeth. Upon sealing, thermal cycling was performed at 500 cycles from 5 ºC to 55 ºC. Next the teeth were submerged in 2 percent methylene blue for 12 h and 24 h at a temperature of 37 ºC. Finally marginal sealing was evaluated in the stereo microscope according to ISO / TS 11405: 2015, using the following scale: grade 0 (no microfiltration), grade 1 (microfiltration as far as the enamel), grade 2 (microfiltration as far as the dentin), and grade 3 (microfiltration as far as the pulp floor). Results: Conditioning with 37 percent phosphoric acid was grade 0 (55.6 percent) and grade 1 (33.3 percent) at 12 h, and grade 1 (55.6 percent) at 24 h, whereas conditioning with 10 percent sodium hypochlorite was grade 0 (44.4%) at 12 h, and predominantly grade 1 (55.6 percent) at 24 h. Hypothesis contrast in related samples yielded 37 percent phosphoric acid and 10 percent sodium hypochlorite at 12 h and 24 h, p= 0.052 and p= 0.584, respectively. Comparison between independent samples at 12 h and 24 h yielded p= 0.462 and p= 0.406, respectively. Conclusions: The 10 percent sodium hypochlorite gel has similar marginal sealing effectiveness as the 37 percent phosphoric acid gel when used as dental conditioners(AU)

La actividad antibacteriana de Camellia sinensis comparada con propóleo frente al Streptococcus mutans / Antibacterial activity of Camellia sinensis versus propolis against Streptococcus mutans

RESUMEN Introducción: El té verde (Camellia sinensis) y el propóleo presentan flavonoides, que inhiben el crecimiento, metabolismo y la coagregación del Streptococcus mutans, principal agente causal de la caries dental. Objetivo: Evaluar la actividad antibacteriana in vitro del extracto etanólico del té verde (Camellia sinensis) al 10 por ciento y 20 por ciento comparado con extracto etanólico de propóleo al 10 por ciento y 20 por ciento, frente al crecimiento de cepas de Streptococcus mutans (ATCC 25175). Métodos: Estudio experimental in vitro, longitudinal, prospectivo y comparativo. El universo estuvo constituido por 90 discos de difusión y la muestra por 15 discos embebidos en té verde (Camellia sinensis) o propóleo a diferentes concentraciones, clorhexidina acuosa al 0,12 por ciento y agua destilada. El tamaño de muestra se calculó por fórmula de comparación de medias, después de realizar un estudio piloto. Se colocaron los discos de difusión embebidos en las sustancias sobre agar Mueller Hinton, sembrado con Streptococcus mutans (ATCC 25175), haciendo medición del ancho de los halos inhibitorios a las 24 y 48 h. Se aplicaron pruebas de comparación no paramétricas de Kruskal Wallis y la prueba rangos de Wilcoxon. Resultados: El máximo ancho de halo inhibitorio logrado por clorhexidina acuosa al 0,12 por ciento, extracto etanólico de té verde (Camellia sinensis) al 20 por ciento y extracto etanólico de propóleo al 20 por ciento fue a las 24 h con valores de 10,64 mm ± 0,924 mm, 6,82 mm ± 0,982 mm y 8,36 mm ± 1,286 mm, respectivamente. El extracto etanólico de té verde (Camellia sinensis) al 20 por ciento, presentó diferencias estadísticamente significativas respecto al extracto etanólico de propóleo al 20 por ciento, tanto a las 24 h (p= 0,013), como a las 48 h (p= 0,011). Conclusiones: Frente al crecimiento de cepas de Streptococcus mutans (ATCC 25175), el extracto etanólico de propóleo al 20 por ciento presenta mayor actividad antibacteriana respecto al extracto etanólico de té verde (Camellia sinensis) al 10 por ciento y 20 por ciento, actividad que disminuye con el paso del tiempo(AU)

ABSTRACT Introduction: Green tea (Camellia sinensis) and propolis contain flavonoids which inhibit the growth, metabolism and co-aggregation of Streptococcus mutans, the main causative agent of dental caries. Objective: Evaluate the antibacterial activity in vitro of 10 percent and 20 percent green tea (Camellia sinensis) ethanolic extract versus 10 percent and 20 percent propolis ethanolic extract against the growth of Streptococcus mutans (ATCC 25175) strains. Methods: An in vitro experimental prospective longitudinal comparative study was conducted. The study universe was 90 diffusion disks and the sample was 15 disks soaked up in green tea (Camellia sinensis) or propolis at various concentrations, 0.12 percent aqueous chlorhexidine and distilled water. Sample size was estimated by the comparison of means formula after conducting a pilot study. The diffusion disks soaked up in the substances were placed on Mueller Hinton agar planted with Streptococcus mutans (ATCC 25175) and the width of the inhibition haloes was measured at 24 h and 48 h. Nonparametric Kruskal-Wallis comparison tests and the Wilcoxon rank test were performed. Results: The maximum width of the inhibition halo achieved by 0.12 percent aqueous chlorhexidine, 20 percent green tea (Camellia sinensis) ethanolic extract, and 20 percent propolis ethanolic extract at 24 h was 10.64 mm ± 0.924 mm, 6.82 mm ± 0.982 mm and 8.36 mm ± 1.286 mm, respectively. The 20 percent green tea (Camellia sinensis) ethanolic extract showed statistically significant differences with respect to the 20 percent propolis ethanolic extract, both at 24 h (p= 0.013) and at 48 h (p= 0.011). Conclusions: The 20 percent propolis ethanolic extract displays greater antibacterial activity against the growth of Streptococcus mutans (ATCC 25175) strains than the 10 percent and 20 percent green tea (Camellia sinensis) ethanolic extract. This activity decreases with the passing of time(AU)