Effectiveness of different toothbrushing patterns among schoolchildren in an urban area of Argentina.

AIM: To identify toothbrushing patterns among schoolchildren with no prior dental hygiene training and associate them with effectiveness for eliminating dental biofilm. MATERIALS AND METHODS: Eight calibrated dentists assessed dental biofilm, toothbrushing procedure and dental status and registered: grip, bristle angle with respect to tooth, type of movement, surfaces brushed, simultaneous brushing of both jaws, including all six sextants and duration of brushing dental biofilm before and after brushing was determined in 944 children. Frequency distribution was calculated for nominal variables and central tendency and dispersion for quantitative variables of the toothbrushing procedure. Effectiveness was evaluated in 236 children by calculating differences between biofilm levels before and after brushing using Student's test. A cutoff value was established for the difference in reductions in biofilm levels by means of an ROC curve. RESULTS: The variables including all 6 sextants and bristle angle showed positive association with biofilm reduction. The cutoff point for biofilm reduction for including all 6 sextants was 66.85% (OR 6.4 [3.6-11.38]). The cutoff value for biofilm reduction for bristle angle was 68.35% (OR 3.2 [1.83-5.8]). CONCLUSION: The variables associated with biofilm reduction can be used to optimize the modality of future educational interventions in schoolchildren.

Disease activity and subcutaneous nodules are associated to severe periodontitis in patients with rheumatoid arthritis.

Rheumatoid arthritis (RA) was significantly associated with increased overall risk of periodontitis, both chronic, inflammatory pathologies leading to connective tissue breakdown and bone destruction. To identify clinical and/or serological variables routinely evaluated during follow-up of people with RA which are associated with the severity of their periodontal disease. An observational, cross-sectional study was carried out, which included RA patients according to ACR/EULAR 2010 criteria having chronic periodontal disease. RA clinical parameters (disease duration, erythrocyte sedimentation rate, serum C-reactive protein, disease activity (DAS28) and rheumatoid factor, presence of bone erosions and rheumatic nodules) and also corticosteroid therapy were considered. Periodontitis was evaluated according to the American Academy of Periodontology (1999) and chronic periodontitis was assessed by full mouth periapical radiographic examination, periodontal probing depth, clinical attachment level and bleeding index. A total of 110 subjects with RA and chronic periodontitis were included. The female/male relation was 5.1, and no significant differences between genres were found in rheumatic or oral variables. RA patients with longer disease duration, higher disease activity and with rheumatic nodules had significantly greater periodontitis severity. Multivariate analysis confirmed that severe periodontitis was associated with DAS283 4.1 (OR 51.4, CI 95% 9.4-281.5) and the presence of rheumatic nodules (OR 6.4, CI 95% 1.3-31.6). Disease activity and rheumatic nodules were strongly associated with severe periodontitis. Based on these findings it would be desirable to include interdisciplinary management at an early stage of RA to ensure comprehensive treatment of both pathologies.

Dental caries lesions and impact on quality of life in adolescents living in urban and rural areas. A case study.

The concept of quality of life (QoL) developed from early studies on subjective wellbeing and satisfaction with life, interpreted as resulting from living conditions, and recognized by means of objective indicators. Indicators have been developed and validated to measure the relationship between quality of life and health Aim: To determine, during an Educational Social Practice, the association between presence of dental caries lesions and its impact on quality of life of adolescents living in rural and urban areas in Argentina. Materials and Method: This was an observational cross-sectional study in (a) a rural area (Tres Isletas; Chaco Province/Schools No. 601 and 477) and (b) an urban area (Villa Soldati; Buenos Aires City/Nuestra Sra. Fátima School). The sample included 40 students from the urban area (UG) and 30 from the rural area (RG). A calibrated researcher (Kappa 0.80) collected the survey data and performed the clinical examinations. The following were recorded: (a) sociodemographic distribution in terms of age and gender; (b) presence of dental biofilm according to Silness and Löe; caries lesions according to ICDAS II /INTCy criteria, and (d) DMFT, total and per component. Quality of life was assessed using the CPQ 11-14r. Statistical processing included calculation of frequency distribution of the variables (X± DS), and chi-square and Mann-Whitney tests to calculate association and comparisons between groups. Results: The sample included 47 girls (67.1%) and 23 boys (32.9%). Distribution according to sex and age did not differ significantly between sites (UG:12.9 years ± 0.5 and RG:11.8 years ±1.1). No significant difference was found between sites for a) plaque biofilm (p=0.759); b) DMFT, total value and per component, or c) individual and grouped ICDAS scores. Percentage analysis of the CPQr 1-14 scores showed significant differences between groups for questionnaire total scores (26.9% ± 2.2 in UG and 4.1% ± 0.8 in RG) and for the different domains. Conclusion: Perceived impact on quality of life caused by dental caries lesions was significantly higher in urban than the rural group, although neither the dental caries process nor the amount of biofilm differed significantly between groups.

El concepto de calidad de vida (CV) se desarrolló a partir de estudios tempranos sobre bienestar subjetivo y satisfacción con la vida3, interpretado como resultante de las condiciones de vida empleando para su reconocimiento. Para medir su relación con la salud se han desarrollado y validado indicadores. Objetivo: Determinar la asociación entre presencia de lesiones de caries dental y el impacto que producen sobre la calidad de vida de adolescentes residentes en áreas rural y urbana República Argentina), en un caso de Practica Social Educativa. Materiales y Método: Estudio observacional de corte transversal en (a) área rural (Tres Isletas; Provincia Chaco/escuelas N° 601 y N° 477) y (b) área urbana (Villa Soldati; CABA/ escuela Nuestra Sra. Fátima). La muestra incluyó 40 escolares residentes en área urbana (GU) y 30 residentes en área rural (GR). Un investigador calibrado (Kappa 0.80) realizó el relevamiento de datos y el examen clínico Se registraron (a) distribución sociodemográfica en términos de edad y género; (b) presencia de biofilm dental segùn Silness y Löe; lesiones de caries según criterios ICDAS II /INTCy (d) cálculo de CPOD total y por componente. La calidad de vida fue evaluada mediante cuestionario CPQ 11-14r. El procesamiento estadístico incluyó cálculo de distribución de frecuencias de las variables (X± DS) y las pruebas chi cuadrado y Mann-Whitney.para calcular asociacion y comparaciones. entre grupos. Resultados: La muestra incluyó 47 mujeres (67,1%) y 23 hombres (32,9%). La distribución según sexo y edad no mostró diferencias significativas entre las sedes (GU:12,9 años ± 0,5 y GR:11,8 años ±1,1). No se encontraron diferencias significativas entre las sedes al comparar a) biofilm de placa (p=0,759); b) CPOD, valor total y por componentes y c) códigos de ICDAS individuales y agrupados. El análisis porcentual del índice CPQr 1-14 reveló diferencias significativas en el puntaje total (26,9% ± 2.2 en GU y 4,1% ± 0.8 en GR) y en los respectivos dominios del instrumento. Conclusión: La percepción del impacto sobre la calidad de vida generado por las lesiones de caries dental resultó significativamente mayor en los escolares urbanos que en los rurales, aunque ni el proceso de caries dental ni la cantidad de biofilm encontrados en cada grupo, revelaron diferencias significativas.

Hyposalivation and periodontal disease as oral non-articular characteristics in rheumatoid arthritis.

OBJECTIVE: To investigate the association among rheumatoid arthritis (RA), saliva production, and periodontal status. METHODS: An observational study was carried out on 103 subjects with RA and 103 without RA matched by sex and age. Rheumatologic evaluation included serological and clinical variables. A full mouth periodontal examination was performed according to the American Academy of Periodontology (1999). Resting and stimulated whole salivary flows were determined after spiting during 5 min. RESULTS: RA was associated with a higher prevalence of severe periodontitis (12% vs. 4%), with a marked reduction in resting and stimulated saliva production, and with a higher prevalence of resting (19% vs. 0%) and also stimulated hyposalivation (54% vs. 10%), compared with the control group. The differences in mean resting and stimulated salivary flows between RA and control groups persisted after the exclusion of people with hyposalivation. Saliva production was not associated with the presence or the severity of periodontal disease, or with the rheumatic clinical characteristics of the patients. CONCLUSIONS: More than 50% of people with RA have some degree of reduction in their salivary flows, an affection not associated with the periodontal status or rheumatic activity, which are the expression of the two related inflammatory diseases. The influence of autonomic dysfunction on hyposalivation can be considered. While periodontitis would be a disease-associated comorbidity of RA, poor saliva production should be included among the extra-articular manifestations. Key Points • Rheumatoid arthritis patients are more prone to suffer from periodontitis and/or hyposalivation. • Periodontal disease is more prevalent in people with rheumatoid arthritis and also an association was found between the severities of both pathologies. • More than 50% of people with RA would have some degree of reduction in their salivary flows, an affection not associated with the periodontal status or rheumatic activity. • Reduced saliva production in rheumatoid arthritis patients should be included among the extra-articular manifestations.

gDNA extraction from Candida albicans and Candida dubliniensis in subgingival samples in Argentina. Evaluation of different methods.

The oral cavity constitutes a unique ecosystem with highly variable ecological niches that harbor a great variety of microorganisms, including yeasts. Molecular methods are currently considered the gold standard for identifying species, although they involve limitations associated with the disruption of yeast cell walls to release the genomic DNA (gDNA) for amplification. AIM: The aim of this study was to compare the performance of different methods for extracting gDNA from Candida albicans and Candida dubliniensis, subsequently amplifying DNA by PCR. MATERIALS AND METHOD: Fifty-two isolates (16 C. albicans and 36 C. dubliniensis) were obtained from subgingival biofilm of HIV+ patients with clinical signs of periodontal disease. The study evaluated 6 gDNA extraction methods and two PCR amplification methods. Furthermore, the presence of alleles of HWP1 gene was determined in C. albicans. RESULTS: Comparisons of six methods show statistically significant differences (p <0.001) except for C. albicans in two of them. For C. dubliniensis, statistical differences were observed in all comparisons. Commercial methods were more efficient for concentrating gDNA than in-house methods, and both PCRs were effective. Ten heterozygous C. albicans isolates for this allele were positive for the HWP1-1 / HWP1-2 allele, one was homozygous for Wild Type HWP1-1 allele, and 5 were homozygous for novel/rare HWP1-2 allele. CONCLUSIONS: This study aims to provide simple, inexpensive strategies for phenotypic identification and molecular confirmation of Candida albicans and Candida dubliniensis for non-reference laboratories with low complexity and/or low budgets.

La cavidad oral constituye un ecosistema único con nichos ecológicos muy variables, capaz de albergar una gran variedad de microorganismos, incluidas las levaduras. Los métodos moleculares son considerados actualmente los métodos de identificación definitivos ya que a diferencia de los anteriores, nos brindan una correcta sensibilidad y especificidad. Sin embargo, existen limitaciones asociadas con la ruptura de las paredes celulares de estas levaduras para liberar el ADN genómico (gADN) necesario para la amplificación. OBJETIVO: El objetivo de este estudio fue comparar el rendimiento de diferentes métodos de extracción de gADN de Candida albicans y Candida dubliniensis, amplificando posteriormente por PCR. Materiales y Método: Se estudiaron 52 aislamientos, 16/52 de Candida albicans y 36/52 de Candida dubliniensis obtenidos de biofilm subgingival de pacientes VIH+ con signos clínicos de enfermedad periodontal. Se evaluaron seis métodos de extracción de gADN y la posterior amplificación se realizó por dos técnicas de PCR. Además en C. albicans se determinó la presencia de alelos para el gen HWP1. RESULTADOS: Las comparaciones de seis métodos son estadísticamente significativas (p<0,001) excepto para C. albicans en dos de ellos. Para C. dubliniensis se observaron diferencias estadísticas en todas las comparaciones. Los métodos comerciales mostraron una mayor eficiencia en la concentración de gADN que los métodos caseros y ambos fueron efectivos en las dos PCR. 10 aislados de C. albicans resultaron positivos para el alelo HWP1-1/HWP1-2, siendo heterocigotos para este alelo. Solo un aislamiento fue homocigoto para el alelo HWP1-1 de tipo salvaje y 5 eran homocigotos para el alelo HWP1-2 nuevo/raro. CONCLUSIONES: Este estudio tiene como objetivo proporcionar estrategias simples y económicas para la identificación fenotípica y confirmación molecular de Candida albicans y Candida dubliniensis para laboratorios de no referencia con baja complejidad y/o bajo presupuesto económico.

Detection of Streptococcus mutans and Streptococcus sobrinus and Their Association with Oral Microbiome Stressors in 6-18-month-old Infants.

Aim: To determine the presence of Streptococcus mutans (S. mutans) and Streptococcus sobrinus (S. sobrinus) and their association with extrinsic and intrinsic variables in 6-18-month-old infants. Methods: This was an analytical, cross-sectional study of 65 6-18-month-old infants who visited the Centers for Early Childhood in Buenos Aires City. Three groups were established according to the presence of teeth-group I (GI)-edentulous infants, group II (GII)-infants with 1-8 teeth, and group III (GIII)-infants with 9-16 teeth. Data on the variables, diet, use of artificial teats, and oral hygiene were gathered using a self-administered questionnaire. An oral examination was performed according to the International Caries Detection and Assessment System (ICDAS II) criterion. A saliva sample was taken by aspiration with a sterile plastic syringe. Cariogenic Streptococci (CS) were counted using the adherence test in modified gold broth (AT-MGB). Molecular detection and quantification were performed by quantitative polymerase chain reaction (qPCR) (gtfB, gtfT, and tuf). Results: A total of 12% of infants received oral hygiene, 38% used bottles, 30% used pacifiers, and 55% had sugar intake. S. sobrinus and S. mutans were detected in 57.1 and 28.6% of the children with caries, respectively. Groups I, II, and III had CS counts of log 2, 3.4, and 3.7, respectively. S. sobrinus was detected in 26.7% of GI, 52.9% of GII, and 85.7% of GIII, while S. mutans was detected in 13.3%, 35.3%, and 57.7%, respectively. Conclusion: The prevalence of S. sobrinus was higher than S. mutans in all groups. The presence of CS was significantly associated with sugar intake. No association was found between S. mutans and S. sobrinus and the presence of caries, hygiene habits, or use of artificial teats. Clinical Significance: This study supports the role of diet in developing a cariogenic biofilm in children under 2 years of age. How to cite this article: Cornejo CF, Soken LJ, Salgado PA, et al. Detection of Streptococcus mutans and Streptococcus sobrinus and Their Association with Oral Microbiome Stressors in 6-18-month-old Infants. Int J Clin Pediatr Dent 2023;16(1):68-73.

Learning strategies of dental students in Buenos Aires, Argentina prior to and during the COVID-19 pandemic.

Various theories have endeavored to explain how knowledge is accessed. Students, in order to learn, need a good repertoire of appropriate metacognitive and self-regulating strategies and knowledge, which they use consciously or unconsciously. Teachers, in addition to knowing how to teach, need to be aware of students' learning strategies, metacognition, and self-regulation, and of the impact of changes associated with recent pandemic scenarios. AIM: The aim of this study was to identify the study strategies preferred by dental students in two different scenarios: prior to and during the pandemic. MATERIALS AND METHOD: The sample consisted of third-year dentistry students at Buenos Aires University (UBA) during 2019 (Group GP, 141 students, face-toface activity) and 2021 (Group GE, 60 students, e-learning during the pandemic). Participants were asked (a) to provide demographic information (sex and age) and (b) to answer the abridged ACRA scale. Statistical treatment included descriptive tests; Chi2, binomial exact and Student's t-test (p<0.05). RESULTS: The proportion of students who participated with respect to total students enrolled was 58.50% in 2019 and 26.20% in 2021, with female gender being significantly higher. There were significant differences in total number of participants during the different periods (p=0.001), and in gender distribution during the pandemic (p=0.007). Comparison between groups GP and GE showed no significant difference regarding preferences expressed in total values for the scale or for the domains. Analysis of preferences according to gender showed significant differences in total group (p=0.007) and the domains CLCS (Cognitive and Learning Control Strategies) (p= 0.008) and LSS (Learning Support Strategies) (p=0.002). The mean values of preferences selected by females were higher. Similar results were found upon analyzing preferences during the pandemic (n= 60) considering total score (p= 0.033) and the domains CLCS (p= 0.035) and LSS (p= 0.007). CONCLUSIONS: The study identified trends towards an increase in the score and consequently greater use of techniques included in the domains related to metacognition, especially among women. There is potential neutralization of the impact created by the methodological shift between the two periods (face-to-face and e-learning) probably as a result of the implicit adaptability, latent in students, regarding digital methodology, which enables them to adapt to learning in challenging situations.

Varias teorías se han esforzado por explicar cómo se accede al conocimiento. Para aprender, los estudiantes necesitan tener un conjunto de estrategias y conocimientos apropiados, y utilizarlos consciente o inconscientemente. Los docentes deben conocer las estrategias de aprendizaje, la metacognición y la autorregulación de los estudiantes, así como el impacto de los cambios asociados con los escenarios pandémicos recientes sobre esas estrategias. OBJETIVO: El objetivo de este estudio fue identificar las estrategias de estudio preferidas por los estudiantes de odontología en diferentes escenarios: previo y durante la pandemia. Materiales y Método: La muestra estuvo conformada por estudiantes de tercer año de la carrera de odontología (UBA) durante el año 2019 (Grupo GP, 141 estudiantes, actividad presencial) y 2021 (Grupo GE, 60 estudiantes, e-learning durante la pandemia). Los participantes proporcionaron información demográfica (sexo y edad) y respondieron el cuestionario ACRA abreviado. El tratamiento estadístico incluyó medidas de tendencia central, dispersión y distribución de frecuencias, prueba Chi2, binomial exacta y prueba t de Student (p<0,05). RESULTADOS: La distribución de estudiantes que participaron con respecto al total de estudiantes matriculados fue de 58,50% en 2019 y 26,20% en 2021, siendo significativamente mayor el género femenino. Hubo diferencias significativas en el número total de participantes durante los diferentes períodos (p=0,001) y en la distribución por género durante la pandemia (p=0,007). La comparación entre los grupos GP y GE no mostró diferencia significativa en cuanto a las preferencias expresadas en valores totales para la escala o para los dominios. El análisis de preferencias según género mostró diferencias significativas en: grupo total (p=0,007) y los dominios ECCA (Estrategias de Control Cognitivo y de Aprendizaje) (p= 0,008) y EAA (Estrategias de Apoyo al Aprendizaje) (p=0,002). Los valores medios de las preferencias seleccionadas por las mujeres fueron más altos. Resultados similares se encontraron al analizar las preferencias durante la pandemia (n= 60) considerando la puntuación total (p= 0,033) y los dominios ECCA (p= 0,035) y EAA (p= 0,007). CONCLUSIONES: El estudio identificó un aumento en el puntaje y consecuentemente un mayor uso de técnicas incluidas en los dominios relacionados con la metacognición, especialmente entre las mujeres. Existe una potencial neutralización del impacto creado por el cambio metodológico entre los dos períodos (presencial y e-learning) probablemente como resultado de la adaptabilidad implícita, latente en los estudiantes, respecto a la metodología digital, que les permita adaptarse al aprendizaje en situaciones desafiantes.

Saliva sampling methods. Cariogenic streptococci count using two different methods of saliva collection in children.

The aim of this study is to compare the efficacy of two methods for collecting saliva samples from infants under 2 years of age for cariogenic streptococci (CS) count. Two collection methods were applied in 11 infants. In Method (A), saliva samples were collected by swabbing the inner cheek mucosa and floor of the mouth in figure of eight motions with a sterile cotton swab until it was soaked. In method (B), saliva samples were collected by aspiration of 1 ml of saliva with a sterile plastic syringe on the floor of the mouth, after stimulation with glove. The samples were cultured in modified Gold's broth (MSMG), and on trypticase, yeast extract, sucrose, cystine and bacitracin culture medium (TYSCB). In method (A), the swab with the sample was unloaded in situ on TYSCB and placed in PBS medium for transport. Then, 100 µl of the eluate was seeded in MSMG. In method (B) 100 µl were seeded in TYSCB and 100 µl in MSMG. Both culture media were incubatedundercapnophilicconditions for 48 hours at 37 °C. Colony forming units (CFU/ml) were counted by calibrated operators (kappa = 0.75). The presence of cariogenic streptococci (CS) (Streptococcus mutans-Streptococcus sobrinus) was determined by qPCR in the samples collected by both methods. The CFU/ml counts in MSMG differed significantly between methods (p = 0.021). In TYSCB, the recovery of CFU/ml was higher in method (A), without significant difference (p = 0.705). The molecular technique detected presence of CS, with no difference between collection methods. Collecting saliva samples by swabbing proved more effective in terms of recovery of microorganisms, and did not affect the detection of presence of CS by molecular techniques.

El objetivo de este estudio es comparar la eficacia de dos métodos de obtención de muestras salivales, en infantes menores de 2 años para el recuento de estreptococos cariogénicos (EC). Se aplicaron dos métodos de recolección en 11 infantes, el método (A), consistió en la recolección de muestras de saliva con hisopos de algodón estériles, realizando movimientos en ocho sobre la mucosa del carrillo y piso de boca, hasta embeber el hisopo. En el método (B) la recolección de las muestras se realizó por aspiración con jeringa plástica estéril en piso de boca hasta obtener 1 ml, luego de estimulación con guante. Las muestras fueron cultivadas en caldo de Gold modificado (MSMG) y medio de cultivo TYSCB (tripticasa, extracto de levadura, sacarosa, cistina y bacitracina). En (A), el hisopo con la muestra fue descargado in situ en TYSCB y colocado en medio de transporte PBS. 100 µl del eluato se sembró en MSMG. En (B) 100 µl fueron sembrados en TYSCB y 100µlen MSMG. Ambosmedios de cultivo fueron incubados en condiciones de capnofilia por 48 hs. a 37°C. El recuento de unidades formadoras de colonias (UFC/ml) se realizó por operadores calibrados (kappa= 0.75). La presencia de EC (Streptococcus mutans - Streptococcus sobrinus) fue determinada por qPCR en las muestras obtenidas por ambos métodos. Los resultados mostraron que los recuentos de UFC/ml en MSMG presentaron diferencias significativas entre ambos métodos (p=0.021) En TYSCB la recuperación de UFC/ml fue mayor en el método (A), sin observarse diferencias significativas (p=0.705). Se detectó la presencia de EC por técnica molecular, sin mostrar diferencias entre los métodos empleados. La recolección de muestra de saliva con hisopo presentó mayor eficacia en términos de recuperación de microorganismos, sin alterar la detección de presencia de EC por técnicas moleculares.

Comparison between indexes for diagnosis and guidance for treatment of dental caries.

The objective of this study was to establish the correlation between an index for caries treatment needs and an index for caries lesions detection and evaluation. A cross-sectional study was performed on three samples of children aged 3 (n = 302), 5 (n = 183), and 11-14 years old (n = 60), attending early childhood centers and schools in the cities of Avellaneda, Rio Grande, and Buenos Aires. Dental caries treatment needs were estimated on every child through the Caries Treatment Needs Index (CTNI) for programming resources allocation. Also, a diagnosis of dental caries was made according to ICDAS II criteria. After the diagnostic procedures, a dental care program was developed. The ICDAS II variable was operationalized by grouping the codes into four categories: G1: code 0; G2: code 1-2; G3: code 3; G4: code 4-5-6. Measures of central tendency and dispersion were calculated for both variables, and the correlation was calculated using the Spearman coefficient. Results revealed that in the group of 3-year-old children, a significant correlation was observed in G1 (rho = -0.822); G2 (rho = 0.330); G3 (rho = 0.509) and G4 (rho = 0.710) between both indexes. For the group of 5-year-old children, a significant correlation was observed in G1 (rho = -0.821); G2 (rho = 0.260); G3 (rho = 0.344) and G4 (rho = 0.840). In the group of children 11-14 years of age, a significant correlation was observed in G1 (rho = -0.692); G3 (rho = 0.437) and G4 (rho = 0.764). The indices analyzed in this study (CTNI and ICDAS II) show reasonable equivalence for use in clinical and epidemiological studies based on the statistical analysis.

El objetivo de este estudio fue establecer la correlación entre un índice de necesidad de tratamiento de caries y un índice para la detección y evaluación de lesiones de caries. Se realizó un estudio de corte transversal en tres muestras de niños de 3 años (n = 302), 5 años (n = 183) y 11-14 años (n = 60), que asistían a centros y escuelas de primera infancia en las ciudades de Avellaneda, Rio Grande y Buenos Aires. Las necesidades de tratamiento de caries dentales se estimaron en cada niño a través del Índice de Necesidad de Tratamiento de Caries (INTC) para la asignación de recursos de programación. Además, se realizó un diagnóstico de caries dental según los criterios de la ICDAS II. Después de los procedimientos de diagnóstico, se desarrolló un programa de atención odontológica. La variable ICDAS II se operacionalizó agrupando los códigos en cuatro categorías: G1: código 0; G2: código 1-2; G3: código 3; G4: código 4-5-6. Se calcularon medidas de tendencia central y dispersión para ambas variables y la correlación se calculó mediante el coeficiente de Spearman. Los resultados revelaron que en el grupo de niños de 3 años se observó una correlación significativa en G1 (rho = -0,822); G2 (rho = 0,330); G3 (rho = 0,509) y G4 (rho = 0,710) entre ambos índices. Para el grupo de niños de 5 años se observó una correlación significativa en G1 (rho = -0,821); G2 (rho = 0,260); G3 (rho = 0,344) y G4 (rho = 0,840). En el grupo de niños de 11 a 14 años se observó una correlación significativa en G1 (rho = -0,692); G3 (rho = 0,437) y G4 (rho = 0,764). Los índices analizados en este estudio (INTC e ICDAS II) muestran una equivalencia razonable para su uso en estudios clínicos y epidemiológicos, basado en el análisis estadístico realizado.

Modalidades de administración de un cuestionario referido a hábitos de salud bucal: análisis de concordancia / Modalities for the administration of a questionnaire on oral health habits: a concordance analysis

Objetivo: Analizar las diferencias entre dos modali-dades de administración de un instrumento, autoad-ministrado o guiado por un investigador, aplicados a tutores legales de infantes de una institución educa-tiva. Materiales y Métodos: muestra de 130 tutores legales de niños/as (3 y 5 años) pertenecientes a un jardín de infantes municipal de Avellaneda. Se aplicó un instrumento de recolección de datos sobre hábi-tos de salud bucal constituido por 14 preguntas sim-ples, múltiples y cerradas. La entrega y devolución del instrumento fue a través de la institución. A los 2 meses se convocó a la misma población para comple-tar el mismo instrumento guiado por un investigador. Se evaluó: porcentajede concurrentes e instrumen-tos respondidos totalmente (modalidad autoadminis-trada), porcentaje de concurrentes que completaron el instrumento guiado y concordancia total y por res-puesta de las 2 modalidades. Se analizaron frecuen-cias y porcentajes. Para comparar la concordancia se utilizó Kappa global y Kappa de Cohen para cada pregunta. Resultados: 76,9% de tutores legales res-pondieron en la modalidad autoadministrada y 48,5% la guiada por el investigador. El 80,0% respondió la totalidad de las preguntas del instrumento autoad-ministrado. Al comparar las respuestas para ambas modalidades, no se observaron diferencias signifi-cativas en la totalidad de las mismas. Al analizar las respuestas solo 3 de las 14 preguntas tuvieron una concordancia menor (0,70). Conclusión: Para la po-blación estudiada, la forma autoadministrada tuvo mayor tasa de respuesta que la guiada por un inves-tigador, sin que se registren diferencias en las res-puestas de ambas formas de administración (AU)

Objective: Analyze the differences between two methods of administration of an instrument, self-administered or guided by a researcher, applied to legal guardians of infants in an educational institution. Materials and Methods: Population 130 legal guardians of children (3 and 5 years old) belonging to a municipal kindergarten in Avellaneda. A data collection instrument on oral health habits was applied, consisting of 14 simple, multiple, and closed questions. The delivery and return of the instrument was through the institution. After 2 months, the same population was called to complete the same instrument guided by a researcher. The following were evaluated: percentage of participants and instruments fully answered (self-administered mode), percentage of participants who completed the guided instrument. The total and response agreement of the 2 modalities was evaluated. Frequencies and percentages were analyzed. To compare agreement, global Kappa was used, and Cohen's Kappa was used for each question. Results: 76.9% of legal guardians responded to the self-administered modality and 48.5% to the one guided by the researcher. 80.0% answered all the questions of the self-administered instrument. When comparing the responses for both modalities, no significant differences were observed in all of them. When analyzing the answers, only 3 of the 14 questions had a lower agreement (0.70). Conclusion: For the population studied, the self-administered form had a higher response rate than the one guided by a researcher, with no differences recorded in the responses of both forms of administration (AU)

Student learning strategies according to years spent studying for a degree in dentistry.

Learning strategies are a set of organized, conscious, intentional tasks performed by a student to achieve a learning objective effectively in a given social context. The aim of the present study was to determine the type and frequency of use of different learning strategies among students taking the subject "Comprehensive Clinic II ", which corresponds to the 3rd year of the 6-year general syllabus of the undergraduate course at the School of Dentistry, Buenos Aires University, and to analyze the use of these learning strategies according to the number of years elapsed between each students admission to dental school and the time he/she took that subject. Dental students (n=189) filled in the Learning and Study Strategies Inventory (LASSI). Seventy-five percent were female. The tool includes 10 dimensions, organized in 77 items. Responses to each question were recorded using a Likert type scale (5 choices). Total scores were obtained by assigning values to the responses. The students were grouped according to time elapsed from year of admission to dental school to the year in which they took the subject (Institutional Persistence, TI). Statistical analysis included mean and confidence intervals for scores (total and for each domain) and comparisons among TI groups using one-way ANOVA and Tukeys post hoc test. Total score for the sample was 275.3 (71.5% of maximum possible score). There were differences in the use of learning strategies reported by dental students in the tool. Students with shorter institutional persistence times scored higher in the following dimensions: attitude and interest, motivation, selfdiscipline, willingness, self-testing and reviewing.

Las estrategias de aprendizaje son un conjunto organizado, consciente e intencional de lo que hace el estudiante para lograr con eficacia un objetivo de aprendizaje en un contexto social dado. El objetivo de este trabajo fue determinar el tipo y frecuencia de uso de estrategias de aprendizaje en estudiantes del curso de Clínica Integrada II, que corresponde al 3er año del programa general de 6 años de la Carrera de Odontología, y analizar su utilización en función del tiempo de permanencia en la Facultad. Los alumnos (n=189) respondieron el cuestionario "Inventario de Estrategias de Aprendizaje y Estudio” (LASSI). Este instrumento consta de 10 dimensiones organizadas en 77 reactivos. Las respuestas a cada reactivo fueron registradas mediante una escala de Likert (5 opciones). El puntaje total se obtuvo mediante asignación de valores a las respuestas elegidas. Los estudiantes fueron agrupados de acuerdo con el tiempo transcurrido entre el ingreso a la carrera y el la fecha en que cursaron la asignatura elegida. (Permanencia institucional, TI). Procesamiento estadístico: cálculo de media e intervalo de confianza para puntajes (total y por dominio) y comparación entre grupos (PI) mediante ANOVA de un factor y post hoc Tukey. El componente femenino fue 75%. El puntaje total para la muestra fue 275,3 (71,5% del máximo posible). Se comprobaron diferencias en el uso de estrategias de aprendizaje. Los alumnos con menor tiempo de permanencia institucional mostraron puntajes mas altos en las siguientes dimensiones: actitud e interés, motivación, autodisciplina, disponibilidad y autoevaluación / repaso.

Microbiological study of the subgingival biofilm in HIV+/HAART patients at a specialized dental service.

The aim of this study was to describe the microbiological profile of HIV patients under highly active antiretroviral treatment (HAART). This crosssectional study comprised 32 HIV patients with periodontal disease (PD) who had been under HAART for more than 6 months. Information about the patients' medical history was obtained from clinical records. Clinical dental examination was performed by a calibrated researcher using standard dental instruments to determine probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP). A total 4,765 periodontal sites were evaluated, 125 of which were also studied microbiologically. Subgingival biofilm samples were obtained using sterile paper points; one set was used for microbiological culture studies and the other for endpoint PCR. Statistical analysis was performed using KruskalWallis and posthoc DunnBonferroni contrast tests. All participants were on HAART at the time of the study, and 90.6% had a viral load below 50 copies / mm3. Prevalence of periodontally active sites was low in the study population. Microbiological studies: Black pigmented anaerobic bacteria and fusiform CFU counts were significantly higher in samples from sites with BOP and PD ≥4mm (p 0.020 and p 0.005, respectively). Molecular Assays: Detection of Porphyromonas gingivalis (p 0.002), Tannerella forsythia (p 0.023) and Treponema denticola (p 0.015) was significantly more frequent at sites with BOP and PD ≥4mm. Conclusions: The patients living with HIV/AIDS under HAART studied here had low prevalence of clinical periodontal disease signs. However, significant detection of P. gingivalis, T. denticola, and T. forsythia in periodontal active sites, and the involvement of these microorganisms as potential HIV reactivators, show the importance of creating awareness among dental health professionals of the need for close dental and periodontal monitoring in HIV patients.

El objetivo de este estudio fue describir el perfil microbiológico del biofilm subgingival de los pacientes con VIH bajo tratamiento antirretroviral de alta actividad (TARGA). El estudio comprendió a 32 pacientes VIH seropositivos con enfermedad periodontal (EP) que se encontraran en tratamiento con TARGA por más de 6 meses. Los antecedentes médicos de los pacientes se obtuvieron de las historias clínicas. El examen clínico instrumental (profun didad de sondaje (PS), nivel de inserción clínico (NIC) y sangrado al sondaje (SS)) fue realizado con instrumental odontológico estándar por un investigador calibrado. De este modo, se evaluaron un total de 4.765 sitios periodontales de los cuales 125 fueron estudiados microbiológicamente. Las muestras de biope lícula subgingival se obtuvieron empleando conos de papel estéril. Las muestras se emplearon en estudios microbiológicos y moleculares por PCR de punto final. El análisis estadístico se realizó según KruskalWallis y pruebas de contrastes posthoc de DunnBonferroni. El 90,6% de la población en estudio presentó carga viral inferior a 50 copias/mm3. La prevalencia de sitios periodontales activos fue baja (1%). Los recuentos de bacterias anaerobias estrictas pigmentadas de negro y fusiformes fueron significativamente más altos en muestras de sitios periodontales con SS positivo y PS ≥4 mm (p 0.020 y p 0.005). La detección molecular de Porphyromonas gingivalis (p 0.002), Tannerella forsythia (p 0.023) y Treponema denticola (p 0.015) fue significativamente mayor en los sitios con SS y PS ≥4mm. La prevalencia del 1% de enfermedad periodontal en el grupo de pacientes estudiados fue menor a la esperada, sin embargo; la detección significativa de P. gingivalis, T. denticola y T. forsythia en sitios periodontales activos y su potencial participación como agentes reactivadores del VIH, nos alerta de la importancia de crear conciencia en los profesionales de la salud (médicos y odontólogos) acerca de la necesidad de un monitoreo minucioso del estado periodontal de pacientes con características semejantes a las descriptas en la muestra poblacional estudiada.

Validation of an adherence assay to detect group mutans streptococci in saliva samples.

The aim of the present study was to validate and establish a cut off point and the predictive value of an adhesion test (AA-MSMG), as a microbiological method for evaluating cariogenic risk. The study is based on a variant (20% sucrose) of a selective medium descripted by Gold et al. (MSMG). This method differentiates mutans group streptococci (MGS) by exacerbating the production of insoluble extracellular polysaccharide which gives adhesion to surfaces such as glass, plastic and dental enamel. Caries assessment according to ICDAS was conducted in 154 patients (aged >21 years) who were attended at Preventive and Community Dentistry Department, School of Dentistry, University of Buenos Aires, Argentina, between August 2017 to August 2018. The study population was assigned to groups according to the presence/ absence of caries lesions: Group A: ICDAS lesion code = 0 (L=0) on all dental surfaces (n=23); and Group B: L>1 (n=131). After mouth-rinsing with distilled water, saliva samples were collected with fasting and hygiene protocol, and sent immediately to the Microbiological Diagnosis Laboratory, Microbiology Department, School of Dentistry, University of Buenos Aires. Samples were homogenized and serially diluted to the tenth. 100 pl of the dilutions were cultured in 25 cm2 sterile plastic flasks containing 9.9 ml of modified selective medium described by Gold (MSMG-selective and differential medium). Cultures were incubated in an anaerobic atmosphere at 36 ± 1°C for 48 hours. The supernatants were eluted and the samples washed with sterile distilled water. Colony forming unit counts were performed by calibrated researchers (Kappa >0.75) using a stereoscopic microscope at 50X. Mutans group streptococci (MGS) counts ranged from 1x104 to 1x105 CFU/ml in group A, and were higher than 1x106 CFU/ml in Group B. Statically analysis of results (ROC) showed that the AAMSMG has a satisfactory predictive value (91%) and established a cutoff point in 1.68x105 UFC / ml. This would indicate that individuals whose MGS saliva counts are higher than the cutoff value would be 5 times more likely to develop dental caries. Adherence assay could be a useful microbiological predictor of caries risk.

El objetivo del presente estudio fue validar, establecer el punto de corte y valor predictivo de una técnica microbiológica para evaluar el nivel de estreptococos del grupo mutans en saliva. La técnica consiste en un test de adherencia que emplea un medio selectivo modificado (20% sacarosa) descripto por Gold et al. (TA-MSMG). Este método permite diferenciar a los estreptococos del grupo mutans (SGM) exacerbando la producción del polisacárido extracelular insoluble que le confiere adhesión a superficies como vidrio, plástico y esmalte dental. De acuerdo con los criterios de ICDAS se sembraron 154 salivas de pacientes mayores de edad, que asistieron al Servicio de Odontología Preventiva y Comunitaria de la Facultad de Odontología de la Universidad de Buenos Aires entre los meses de agosto de los años 2017 y 2018. La población estudiada fue asignada a dos grupos según la presencia / ausencia de lesiones de caries: Grupo A: código de lesión ICDAS = 0 (L = 0) en todas las superficies dentales (n = 23); y Grupo B: L> 1 (n = 131). Después de realizar un enjuague bucal con agua destilada, las muestras de saliva se recogieron según protocolo (ayuno de 4 horas y suspensión de higiene dental de 12 hs). Las muestras se remitieron de inmediato al Laboratorio de Diagnóstico Microbiológico, Departamento de Microbiología de la Facultad de Odontología, Universidad de Buenos Aires. Para su procesamiento, las muestras fueron homogeneizadas y diluidas al décimo. Se cultivaron 100 pl de las diluciones en botellas de plástico estériles de 25 cm2 que contenían 9,9 ml de medio de Gold modificado (MSMG-20% sacarosa). Los cultivos se incubaron en atmósfera anaeróbica a 36 ± 1°C durante 48 horas. El sobrenadante se eluyó y las muestras se lavaron con agua destilada estéril. Los recuentos de unidades formadoras de colonias SGMfueron realizados por investigadores calibrados (Kappa >0.75) utilizando un microscopio estereoscópico a 50X. Los recuentos de SGM presentaron una variación entre 1x104y 1x105 UFC/ml en el grupo A, mientras que en el Grupo B fueron superiores a 1x106 UFC/ml. El análisis estadístico de los resultados determinó una curva ROC que establece para el TA-MSMG un valor predictivo del 91% y un punto de corte en 1.68x105 UFC SGM / ml. Esto indicaría que los individuos cuyos recuentos en saliva de SGM sean superiores al valor de corte, tendrían 5 veces más posibilidades de desarrollar caries (5:1). Este método podría ser un instrumento útil al momento de evaluar (indicador microbiológico) el riesgo cariogénico del paciente.

gDNA extraction from Candida albicans and Candida dubliniensis in subgingival samples in Argentina. Evaluation of different methods / Evaluación de diferentes métodos de extracción de gADN en Candida albicans y Candida dubliniensis en muestras subgingivales en Argentina

ABSTRACT The oral cavity constitutes a unique ecosystem with highly variable ecological niches that harbor a great variety of microorganisms, including yeasts. Molecular methods are currently considered the gold standard for identifying species, although they involve limitations associated with the disruption of yeast cell walls to release the genomic DNA (gDNA) for amplification. Aim: The aim of this study was to compare the performance of different methods for extracting gDNA from Candida albicans and Candida dubliniensis, subsequently amplifying DNA by PCR. Materials and Method: Fifty-two isolates (16 C. albicans and 36 C. dubliniensis) were obtained from subgingival biofilm of HIV+ patients with clinical signs of periodontal disease. The study evaluated 6 gDNA extraction methods and two PCR amplification methods. Furthermore, the presence of alleles of HWP1 gene was determined in C. albicans. Results: Comparisons of six methods show statistically significant differences (p<0.001) except for C. albicans in two of them. For C. dubliniensis, statistical differences were observed in all comparisons. Commercial methods were more efficient for concentrating gDNA than in-house methods, and both PCRs were effective. Ten heterozygous C. albicans isolates for this allele were positive for the HWP1-1 / HWP1-2 allele, one was homozygous for Wild Type HWP1-1 allele, and 5 were homozygous for novel/rare HWP1-2 allele. Conclusions: This study aims to provide simple, inexpensive strategies for phenotypic identification and molecular confirmation of Candida albicans and Candida dubliniensis for non-reference laboratories with low complexity and/or low budgets.

RESUMEN La cavidad oral constituye un ecosistema único con nichos ecológicos muy variables, capaz de albergar una gran variedad de microorganismos, incluidas las levaduras. Los métodos moleculares son considerados actualmente los métodos de identificación definitivos ya que a diferencia de los anteriores, nos brindan una correcta sensibilidad y especificidad. Sin embargo, existen limitaciones asociadas con la ruptura de las paredes celulares de estas levaduras para liberar el ADN genómico (gADN) necesario para la amplificación. Objetivo: El objetivo de este estudio fue comparar el rendimiento de diferentes métodos de extracción de gADN de Candida albicans y Candida dubliniensis, amplificando posteriormente por PCR. Materiales y Método: Se estudiaron 52 aislamientos, 16/52 de Candida albicans y 36/52 de Candida dubliniensis obtenidos de biofilm subgingival de pacientes VIH+ con signos clínicos de enfermedad periodontal. Se evaluaron seis métodos de extracción de gADN y la posterior amplificación se realizó por dos técnicas de PCR. Además en C. albicans se determinó la presencia de alelos para el gen HWP1. Resultados: Las comparaciones de seis métodos son estadísticamente significativas (p<0,001) excepto para C. albicans en dos de ellos. Para C. dubliniensis se observaron diferencias estadísticas en todas las comparaciones. Los métodos comerciales mostraron una mayor eficiencia en la concentración de gADN que los métodos caseros y ambos fueron efectivos en las dos PCR. 10 aislados de C. albicans resultaron positivos para el alelo HWP1-1/HWP1-2, siendo heterocigotos para este alelo. Solo un aislamiento fue homocigoto para el alelo HWP1-1 de tipo salvaje y 5 eran homocigotos para el alelo HWP1-2 nuevo/raro. Conclusiones: Este estudio tiene como objetivo proporcionar estrategias simples y económicas para la identificación fenotípica y confirmación molecular de Candida albicans y Candida dubliniensis para laboratorios de no referencia con baja complejidad y/o bajo presupuesto económico.

Is cold blood cardioplegia absolutely superior to cold crystalloid cardioplegia in aortic valve surgery?

BACKGROUND: Experimental evidence suggests that blood cardioplegia (BCP) may be superior to cold crystalloid cardioplegia (CCP) for myocardial protection. However, robust clinical data are lacking. We compared postoperative outcome of patients undergoing aortic valve replacement (AVR) using cold anterograde-retrograde intermittent BCP versus anterograde (CCP). METHODS: Adult consecutive isolated AVR performed between April 2006 and February 2011 at the Royal Infirmary Hospital of Edinburgh were retrospectively analyzed. The use of anterograde CCP was compared with that of intermittent anterograde-retrograde cold BCP. End points were intra-operative mortality, 30-day hospital re-admission, need for RBC or platelet transfusion, mechanical ventilation time and renal failure. RESULTS: Of total 774 cases analyzed, 592 cases of BCP and 182 cases of CCP were identified. Demographics did not differ between groups (mean age: 67±12 years in CCP and 69±12 years in BCP). Groups (BCP vs. CCP) were indistinguishable (P>0.05, not significant) based on: average aortic cross clamp time 77.01±14.47 vs. 75.78±18.78 minutes, cardiopulmonary bypass time 104.07±43.70 vs. 100.34±25.90 minutes, surgery time 190.53±61.80 vs. 204.04±51.09 minutes and postoperative total blood consumption 1.38±2.11 vs. 1.61±2.4 units. The percentage of patients who required platelets' transfusion was similar: 12.8% BCP and 18.7% CCP (Fisher's exact test, P=0.053). Prevalence of respiratory failure was lower in BCP than in CCP: 2.6% vs. 6.3% (P=0.028). Admission time (days) at ICU was 3.63± 21.90 in BCP and 3.07±8.04 in CCP (not significant). Intra-hospital mortality, 30-day hospital re-admission, renal failure, sepsis, wound healing and stroke did not differ between groups. CONCLUSIONS: BCP was strictly not superior to CCP in every aspect. In particular it was definitely not superior in terms of postoperative ventricular function. Our results question the absolute superiority of BCP over CCP in terms of hard outcomes. Likelihood of serious complications should be considered to improve risk profile of patients before choosing a cardioplegic solution.

Estrategias de autorregulación del aprendizaje en contextos virtuales en estudiantes de odontología / Strategies for the self-regulation of learning in virtual contexts in dental students

Objetivo: Comparar estrategias de autorregulación del aprendizaje en contextos virtuales de estudiantes de la carrera de odontología. Métodos: Participantes: estudiantes de 5 asignaturas de la carrera de odon-tología (N=1514). Instrumento: escala de auto-re-porte validada con 25 reactivos agrupados en 5 dimensiones: D1) Estrategias de planeación y control; D2) Atribuciones motivacionales; D3) Trabajo colabo-rativo con compañeros; D4) Apoyo del asesor en las tareas. La muestra se agrupó en 3: (G3) cursantes del último año de la carrera; (G2) de asignaturas in-termedias; (G1) de primer año. Se utilizaron: ANOVA de medidas repetidas y test de Tukey como post-hoc; tests de X2 y comparación de proporciones con post-hoc de Bonferroni. Resultados: Puntajes por grupo (media±DS-%): D1) G3=39,2±5,6-78,5%; G2=38,8±6,1-77,6%; G1=36,7±5,7-73,1%. D2) G3=14,4±5,2-57,4%; G2=15,5±5,1-61,9%; G1=14,8±5,6-59,3%. D3) G3=22,8±3,1-91,2%; G2=21,2±4,3-84,7%; G1=18,9±6,5­76,3%. D4) G3=15,5±4,5­61,9%; G2=15,8±4,6-63,1%; G1=16,4±4,0-65,8%. Diferencias significativas: entre G1 y G3 en D1 (p=0,014) y entre los tres grupos en D3 (p<0,001). G1 y G3 se diferenciaron (p<0,05) en cin-co de los 10 reactivos de D1 y en todos los reactivos de D3. Conclusiones: Los estudiantes de primer año reportaron menos estrategias de planeación y con-trol. El trabajo colaborativo mostró un incremento a lo largo de la carrera (AU)

Objective: To compare self-regulated learning strat-egies in virtual contexts (VC) among dental students. Methods: Participants: Undergraduate dental students attending five subjects. (N=1514). We used a validat-ed self-report scale with 25 items grouped into five dimensions: D1) planning and control strategies, D2) motivational attributes, D3) collaborative work with colleagues, and D4) support from the advisor Statistical analysis: The relative percentage of the max-imum score was calculated. Students were grouped into 3: those in the last year of their degree (G3), an intermediate group (G2), and freshmen (G1). We used repeated measures ANOVA and Tukey's post-hoc test to compare the relative weights of the dimensions; X2 test, proportion comparisons, and Bonferroni post-hoc test were used for comparisons. Results: Scores by group (mean±SD-%): D1) G3=39.2±5.6-78.5%; G2=38.8±6.1-77.6%; G1=36.7±5.7-73.1%. D2) G3=14.4±5.2-57.4%; G2=15.5±5.1-61.9%; G1=14.8±5.6-59.3%. D3) G3=22.8±3.1-91.2%; G2=21.2±4.3-84.7%; G1=18.9±6.5­76.3%. D4) G3=15.5±4.5­61.9%; G2=15.8±4.6-63.1%; G1=16.4±4.0­65.8%. Significant differences were observed between G1 and G3 on D1 (p=0.014), and between the three groups on D3 (p<0.001). G1 and G3 differed (p<0.05) in five of the 10 D1 items and in all D3 items. Conclusions: Freshmen reported the lowest number of planning and control strategies. Collaborative work increased throughout the career (AU)

Learning strategies of dental students in Buenos Aires, Argentina prior to and during the COVID-19 pandemic / Impacto de la pandemia por covid-19 sobre las estrategias de aprendizaje de los estudiantes de odontología en Buenos Aires, Argentina

ABSTRACT Various theories have endeavored to explain how knowledge is accessed. Students, in order to learn, need a good repertoire of appropriate metacognitive and self-regulating strategies and knowledge, which they use consciously or unconsciously. Teachers, in addition to knowing how to teach, need to be aware of students' learning strategies, metacognition, and self-regulation, and of the impact of changes associated with recent pandemic scenarios. Aim: The aim of this study was to identify the study strategies preferred by dental students in two different scenarios: prior to and during the pandemic. Materials and Method: The sample consisted of third-year dentistry students at Buenos Aires University (UBA) during 2019 (Group GP, 141 students, face-toface activity) and 2021 (Group GE, 60 students, e-learning during the pandemic). Participants were asked (a) to provide demographic information (sex and age) and (b) to answer the abridged ACRA scale. Statistical treatment included descriptive tests; Chi2, binomial exact and Student's t-test (p<0.05). Results: The proportion of students who participated with respect to total students enrolled was 58.50% in 2019 and 26.20% in 2021, with female gender being significantly higher. There were significant differences in total number of participants during the different periods (p=0.001), and in gender distribution during the pandemic (p=0.007). Comparison between groups GP and GE showed no significant difference regarding preferences expressed in total values for the scale or for the domains. Analysis of preferences according to gender showed significant differences in total group (p=0.007) and the domains CLCS (Cognitive and Learning Control Strategies) (p= 0.008) and LSS (Learning Support Strategies) (p=0.002). The mean values of preferences selected by females were higher. Similar results were found upon analyzing preferences during the pandemic (n= 60) considering total score (p= 0.033) and the domains CLCS (p= 0.035) and LSS (p= 0.007). Conclusions: The study identified trends towards an increase in the score and consequently greater use of techniques included in the domains related to metacognition, especially among women. There is potential neutralization of the impact created by the methodological shift between the two periods (face-to-face and e-learning) probably as a result of the implicit adaptability, latent in students, regarding digital methodology, which enables them to adapt to learning in challenging situations.

RESUMEN Varias teorías se han esforzado por explicar cómo se accede al conocimiento. Para aprender, los estudiantes necesitan tener un conjunto de estrategias y conocimientos apropiados, y utilizarlos consciente o inconscientemente. Los docentes deben conocer las estrategias de aprendizaje, la metacognición y la autorregulación de los estudiantes, así como el impacto de los cambios asociados con los escenarios pandémicos recientes sobre esas estrategias. Objetivo: El objetivo de este estudio fue identificar las estrategias de estudio preferidas por los estudiantes de odontología en diferentes escenarios: previo y durante la pandemia. Materiales y Método: La muestra estuvo conformada por estudiantes de tercer año de la carrera de odontología (UBA) durante el año 2019 (Grupo GP, 141 estudiantes, actividad presencial) y 2021 (Grupo GE, 60 estudiantes, e-learning durante la pandemia). Los participantes proporcionaron información demográfica (sexo y edad) y respondieron el cuestionario ACRA abreviado. El tratamiento estadístico incluyó medidas de tendencia central, dispersión y distribución de frecuencias, prueba Chi2, binomial exacta y prueba t de Student (p<0,05). Resultados: La distribución de estudiantes que participaron con respecto al total de estudiantes matriculados fue de 58,50% en 2019 y 26,20% en 2021, siendo significativamente mayor el género femenino. Hubo diferencias significativas en el número total de participantes durante los diferentes períodos (p=0,001) y en la distribución por género durante la pandemia (p=0,007). La comparación entre los grupos GP y GE no mostró diferencia significativa en cuanto a las preferencias expresadas en valores totales para la escala o para los dominios. El análisis de preferencias según género mostró diferencias significativas en: grupo total (p=0,007) y los dominios ECCA (Estrategias de Control Cognitivo y de Aprendizaje) (p= 0,008) y EAA (Estrategias de Apoyo al Aprendizaje) (p=0,002). Los valores medios de las preferencias seleccionadas por las mujeres fueron más altos. Resultados similares se encontraron al analizar las preferencias durante la pandemia (n= 60) considerando la puntuación total (p= 0,033) y los dominios ECCA (p= 0,035) y EAA (p= 0,007). Conclusiones: El estudio identificó un aumento en el puntaje y consecuentemente un mayor uso de técnicas incluidas en los dominios relacionados con la metacognición, especialmente entre las mujeres. Existe una potencial neutralización del impacto creado por el cambio metodológico entre los dos períodos (presencial y e-learning) probablemente como resultado de la adaptabilidad implícita, latente en los estudiantes, respecto a la metodología digital, que les permita adaptarse al aprendizaje en situaciones desafiantes.

Comparación del desempeño técnico-asistencial en programas escolares con diferentes modalidades de implementación / Comparison of technical-assisstance performance in school programs with different implementation modalities

Se comparó el desempeño técnico-asistencial de 2 programas de atención odontológica con iguales protocolos de atención y diferente modalidad de implementación. Ambos programas se caracterizaron por un perfil preventivo-promocional; uso de protocolos validados según riesgo biológico, atención odontológica adaptada a sedes no convencionales, recursos asignados por método de necesidades; ejecución por recurso humano pre-profesional supervisado y modulación por altas. La modalidad de implementación difirió en la densidad/concentración de las actividades realizadas: en el Programa Extensivo (PE) las acciones se implementaron con frecuencia semanal; en el Programa Intensivo (PI) las acciones se concentraron en una semana en el año. Cobertura anual: PE = 120 escolares de 6 a 9 años de edad; PI = 180 escolares y preescolares de 3 a 12 años de edad. Se midió la cantidad de prestaciones, sesiones y tiempo -en minutos- hasta alcanzar el Alta Básica Operativa (ABO). Para comparar grupos (PI y PE) se utilizaron los tests: U de Mann Whitney, t de Student para mues-tras independientes, chi cuadrado y comparación de proporciones. La razón de prestaciones/sesión fue significativamente mayor (p=0,000) en el programa intensivo. El número de prestaciones hasta el alta (ABO) y la razón tiempo/sesión no mostraron diferencias entre programas (p=0,8 p=0,087), mientras que se evidenció una mayor razón tiempo/prestación y tiempo en alcanzar el alta (ABO) en la modalidad extensiva (p=0,000). La modalidad intensiva mostró mayor eficiencia en el desempeño técnico asistencial que la extensiva (AU)

Aim: To compare technical-care performance of 2 dental care programs with the same care protocols and different implementation modalities. Both programs shared the following features: preventive-promotional profile; use of validated clinical protocols according to biological risk, dental care adapted to non-conventional settings, allocation of resources by needs method; supervised pre-professional human resource and modulation by discharges. The implementation mode differed in the density/concentration of the activities: in the extensive program (EP) the actions were implemented on a weekly basis along the year; in the intensive program (IP) the actions were concentrated in one week in the year. Annual coverage of the programs: 180 schoolchildren and preschoolers (3 -12 years old); EP = 120 schoolchildren (6 - 9 years old). We measured the following variables: the number of dental services performed, the number of sessions and the time, in minutes, to reach the basic operating discharge (BOD). We used the following tests to compare groups (IP and EP): Mann Whitney U; Student's t for independent samples, chi square and comparison of proportions test. The action per session ratio was significantly higher (p=0.000) in the intensive program. The number of actions performed until discharge (BOD) and the time per session ratio did not show differences between programs (p=0.8 p=0.087). In the extensive mode, compared to intensive mode, it took longer to reach discharge (BOD) (p=0.000) The program implemented with intensive modality (PI) showed greater efficiency regarding technical-care performance when compared to the extensive mode (AU)

Saliva sampling methods. Cariogenic streptococci count using two different methods of saliva collection in children / Recuento de estreptococos cariogénicos a partir de dos métodos de obtención de saliva en niños

ABSTRACT The aim of this study is to compare the efficacy of two methods for collecting saliva samples from infants under 2 years of age for cariogenic streptococci (CS) count. Two collection methods were applied in 11 infants. In Method (A), saliva samples were collected by swabbing the inner cheek mucosa and floor of the mouth in figure of eight motions with a sterile cotton swab until it was soaked. In method (B), saliva samples were collected by aspiration of 1 ml of saliva with a sterile plastic syringe on the floor of the mouth, after stimulation with glove. The samples were cultured in modified Gold's broth (MSMG), and on trypticase, yeast extract, sucrose, cystine and bacitracin culture medium (TYSCB). In method (A), the swab with the sample was unloaded in situ on TYSCB and placed in PBS medium for transport. Then, 100 μl of the eluate was seeded in MSMG. In method (B) 100 μl were seeded in TYSCB and 100 μl in MSMG. Both culture media were incubated under capnophilic conditions for 48 hours at 37 °C. Colony forming units (CFU/ml) were counted by calibrated operators (kappa = 0.75). The presence of cariogenic streptococci (CS) (Streptococcus mutans-Streptococcus sobrinus) was determined by qPCR in the samples collected by both methods. The CFU/ml counts in MSMG differed significantly between methods (p = 0.021). In TYSCB, the recovery of CFU/ml was higher in method (A), without significant difference (p = 0.705). The molecular technique detected presence of CS, with no difference between collection methods. Collecting saliva samples by swabbing proved more effective in terms of recovery of microorganisms, and did not affect the detection of presence of CS by molecular techniques.

RESUMEN El objetivo de este estudio es comparar la eficacia de dos métodos de obtención de muestras salivales, en infantes menores de 2 años para el recuento de estreptococos cariogénicos (EC). Se aplicaron dos métodos de recolección en 11 infantes, el método (A), consistió en la recolección de muestras de saliva con hisopos de algodón estériles, realizando movimientos en ocho sobre la mucosa del carrillo y piso de boca, hasta embeber el hisopo. En el método (B) la recolección de las muestras se realizó por aspiración con jeringa plástica estéril en piso de boca hasta obtener 1 ml, luego de estimulación con guante. Las muestras fueron cultivadas en caldo de Gold modificado (MSMG) y medio de cultivo TYSCB (tripticasa, extracto de levadura, sacarosa, cistina y bacitracina). En (A), el hisopo con la muestra fue descargado in situ en TYSCB y colocado en medio de transporte PBS. 100 μl del eluato se sembró en MSMG. En (B) 100 μl fueron sembrados en TYSCB y 100 μl en MSMG. Ambos medios de cultivo fueron incubados en condiciones de capnofilia por 48 hs. a 37°C. El recuento de unidades formadoras de colonias (UFC/ml) se realizó por operadores calibrados (kappa= 0.75). La presencia de EC (Streptococcus mutans - Streptococcus sobrinus) fue determinada por qPCR en las muestras obtenidas por ambos métodos. Los resultados mostraron que los recuentos de UFC/ml en MSMG presentaron diferencias significativas entre ambos métodos (p=0.021) En TYSCB la recuperación de UFC/ml fue mayor en el método (A), sin observarse diferencias significativas (p=0.705). Se detectó la presencia de EC por técnica molecular, sin mostrar diferencias entre los métodos empleados. La recolección de muestra de saliva con hisopo presentó mayor eficacia en términos de recuperación de microorganismos, sin alterar la detección de presencia de EC por técnicas moleculares.

Periventricular nodular and subcortical neuronal heterotopia in adult epileptic patients.

Developmental malformations are brain abnormalities that occur during embryogenesis. Neuronal migration disorders, including heterotopic lesions, constitute one type of such abnormalities. The aim of the study was to compare the epileptic clinical patterns of patients with periventricular nodular heterotopia (PNH) (G1) with those affected by subcortical heterotopia (SCH) (G2) looking for differences between both groups which, eventually, might suggest the type of the underlying malformation. The variables studied in both groups were: type of the heterotopia depicted on MRI studies, sex, age, age at seizure onset, annual seizure frequency, localization of the ictal symptomatogenic zone, characteristics of the EEG, other associated anomalies on the magnetic resonance images (MRI) besides the heterotopia, and response to treatment. The only difference found between both groups was the type of heterotopia as shown by MRI studies. The other assessed variables did not significantly (p>0.05) differ between groups. No differences in the clinical features characterizing epilepsy could be found in patients with PNH or SCH, being the images the only tool able to differentiate them.