Effect of ethanol-conditioned dentine on sealer penetration into dentinal tubules: a confocal microscopy study

Aim: The aim of this study was to evaluate the effect of ethanol-conditioned dentin on endodontic sealer penetration into dentinal tubules by confocal laser scanning microscopy (CLSM). Methods: Forty human maxillary anterior teeth were instrumented and divided into four groups (n = 10) according to the drying methods: 1) wet: vacuum only, 2) paper points: vacuum + absorbent paper points, (3) 70% ethanol: 70% ethanol (1 min) + vacuum + absorbent paper points, and (4) 100% ethanol: 100% ethanol (1 min) + vacuum + absorbent paper points. All root canals were filled with resin-based endodontic sealer. Four sections from each third (cervical, middle, and apical) were examined by CLSM. Root canal wall perimeter infiltrated by sealer, maximum depth of sealer penetration, percentage of penetrated area, and fluorescence intensity of rhodamine B were measured. Statistical analysis was performed by analysis of variance and Tukey's tests (α = 0.05). Results: No statistical difference was found when percentage of root canal wall coverage infiltrated by sealer were compared. The groups in which ethanol solutions were used presented greater depth of sealer penetration, higher percentage of penetrated area, and higher fluorescence intensity of rhodamine B (p< 0.05) when compared with the wet and paper point groups. Overall, 100% ethanol produced better results than 70% ethanol, except for rhodamine B intensity (cervical third). In addition, the absorbent paper points drying method behaved better than did vacuum only group, except for rhodamine B intensity (apical third). Conclusion: Ethanol-conditioned dentin improved the penetration of resin-based sealer into dentinal tubules, especially at the concentration of 100%

Teaching experiences during the SARS-COV-2 pandemic in a Brazilian School of Dentistry

The coronavirus outbreak (2019) represents a public health emergency of global concern. Several measures have been taken to minimise the risk of infection among the population, including social distancing, working from home, closure of non-essential activities since the detection of the first case in Brazil. This study describes the teaching experiences during the SARS-COV-2 pandemic in a Brazilian School of Dentistry. The State University of Campinas (UNICAMP) was the first public university in Brazil to stop all the classroom activities on 13th of March 2020 due to COVID-19, followed by other universities. UNICAMP developed several initiatives and created a special support page for digital teaching, where it is possible to obtain guidance, support materials for teachers and a space for exchanging messages (e-mail and chat) for specific guidelines. UNICAMP has started lending computer equipment to undergraduate and graduate students according to socioeconomic criteria. Along with the equipment, 500 chips have been delivered with 10 GB of internet so that these students are able to access the network and carry out the remote activities related to their courses. In conclusion, quality education is the key-element in forming high-quality professionals that will in a near future provide health care for the community, be part in international research groups and become lecturers