Mesenchymal adipose stem cells maintain the capacity for differentiation and survival in culture beyond the long term.

Mesenchymal cells (MSCs) are considered to be cellular populations of common embryological origin. For clinical research applications, MSCs are expanded and increased with cells obtained from a primary culture. By extracting cells from tissue and encouraging them to reproduce, the stem cell population ends up dominating the culture due to a high proliferation rate and self-renewal. The first subcultures between the third and sixth are chosen in order to obtain the maximum number of cells with optimal differentiation capacity. However, few studies have reported long-term cultivation of MSCs. The objective of this study was to advance the knowledge on the characteristics of MSCs by assessing their capacity for self-renewal and phenotypic maintenance beyond 50 cell subcultures, which is defined as the normal limit for cellular survival. Rat subcutaneous adipose tissue was the source of mesenchymal adipose stem cells (MASCs) cultured over 175 subcultures. Early 1 to 5 and late 25 to 30 subcultures were used to induce cellular differentiation to become adipogenic, chondrogenic and osteogenic connective tissue cells. MASCs characteristics were studied using flow cytometry, transmission electron microscopy (TEM), and immunohistochemical and reverse transcription polymerase chain reaction (RT-qPCR) assays. The MASCs maintained cell differentiation capacity for more than 30 subcultures but lost potentiality starting at 60 up to 175 subcultures. MASCs showed the embryonic phenotypes OCT3/4 and Nanog indefinitely, and developed compensatory mechanisms, such as autophagy, to achieve cell survival over a long time period. Therefore, long-term subcultures showed that MASCs could maintain their potential for clinical research use.

Concerns, Knowledge, and Practices of Dentists in Mexico Regarding Infection Control during the Coronavirus Disease Pandemic: A Cross-Sectional Study.

Dentists are highly exposed and vulnerable during the coronavirus disease (COVID-19) pandemic, as physical proximity to patients is necessary for effective dental examination and treatment. The objective of this study was to describe the concerns, knowledge, and infection control practices of dentists in Mexico during the COVID-19 pandemic. In this cross-sectional study conducted from 22 May 2020 to 8 July 2020, an anonymous survey was distributed to dentists, which covered information regarding dentists' sociodemographic and professional characteristics, clinical practices during the pandemic, and perceptions regarding the application of infection prevention and control guidance for dental settings during the COVID-19 pandemic. Out of 703 respondents, 73.1% (n = 514) were women and 53.6% (n = 377) were dentists with 1-10 years of experience. Regarding the statements issued by the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC), the responses for 11 survey items had total agreement rates >90% (high frequency); seven and nine items had moderate and low frequency of total agreement, respectively. Most dentists in this study agreed with the WHO and CDC statements and were concerned regarding the possibility of infection, despite using the protective gear.

Assessing the effectiveness of an online dental pharmacology course.

OBJECTIVES: Undergraduate dentistry students in their final year often lack the knowledge and confidence required to prescribe oral health medications. Online courses could help to solve this problem through augmenting traditional teaching methods. This study assessed the effectiveness of a non-curricular, online, clinical case-based dental pharmacology course designed to improve medication management in senior dentistry students. MATERIALS AND METHODS: This study developed and implemented an online dental pharmacotherapy course for 287 dentistry students in Mexico. Pre- and post-course tests evaluated knowledge acquisition, and a 5-point Likert scale questionnaire was administered to 238 participants to evaluate the course's content and educational strategies. RESULTS: Mean knowledge scores significantly increased from pre- (5.5 ± 1.6) to post-test (9.1 ± 1.3, P < 0.001). Participants reported a high satisfaction level (70.2%) with the course content and materials, educational techniques, and instructors. CONCLUSION: These findings support the use of online, clinically based dental pharmacotherapy courses, in conjunction with traditional teaching methods, as a viable strategy for effectively educating dentistry students.

Correlation between caries history and laser fluorescence of sound tooth enamel in restored and unrestored dentition.

The aim of this study was to determine the correlation between laser fluorescence (LF) values of apparently sound tooth enamel and caries history. LF measurements were recorded from six sound enamel tooth surfaces in each of 346 subjects aged 8-25 years. Caries experience was evaluated using the decayed, missing, and filled tooth (DMFT) index and the International Caries Detection and Assessment System (ICDAS). To measure differences between the unrestored and restored tooth groups, an unpaired two-sample t-test was used. To assess the relationship between LF of sound enamel and caries experience based on the DMFT and ICDAS, Pearson's correlation coefficient and linear regression analyses were used. The LF values of sound dental enamel in subjects with no history of invasive dental treatment were highly correlated with caries experience, as measured by the DMFT index (R = 0.76) and ICDAS (R = 0.7). The LF values of sound enamel in subjects with a history of previous invasive dental treatment were weakly correlated with caries experience, as measured by the DMFT index (R = 0.33), and moderately correlated with the ICDAS values (R = 0.66). The LF value of clinically healthy tooth enamel correlates with caries status based on the DMFT or ICDAS.