Online videos: The hidden curriculum

Introduction: Dental undergraduates will access the Internet searching for learning materials to complement their training; however, open access content is not generally recommended by dental schools. This study aimed to evaluate how dental students are using online video content. Materials and Methods: Students from eight Universities (Athens, Birmingham, Brescia, Cardiff, Melbourne, Paris, Sao Paulo and Valdivia) representing three continents were invited to complete a survey on their access and learning from online videos. Results: International students behave similarly when studying dental content online. Of 515 respondents, 94.6% use the Internet as a learning tool. It was observed that videos are not frequently recommended during didactic lectures (9.6%). But many students (79.9%) will use YouTube for their learning which includes clinical procedures. Students will check online content before performing procedures for the first time (74.8%), to understand what was explained in class (65.9%) or read in books (59.5%), to relearn clinical techniques (64.7%) and to visualise rare procedures (49.8%). More than half of the students do not fully trust the accuracy or the reliability of online content. This does not prevent students from watching and sharing dental videos with classmates (64.4%). The content watched is not shared with teachers (23.3%) even when it contradicts what was learnt in the school (38.2%). Conclusion: This study concludes that students regularly integrate open access digital resources into learning portfolios but are hesitant to inform their teachers about their viewing habits. Students wish to receive critical skills on how to evaluate the material they encounter outside their traditional learning space

Surface Roughness of Commercial Composites after Different Polishing Protocols: An Analysis with Atomic Force Microscopy

Polishing may increase the surface roughness of composites, with a possible effect on bacterial growth and material properties. This preliminary in vitro study evaluates the effect of three different polishing systems (PoGo polishers, Enhance, Venus Supra) on six direct resin composites (Gradia Direct, Venus, Venus Diamond, Enamel Plus HFO, Tetric Evoceram, Filtek Supreme XT)

In vitro assessment of tooth color alteration by two different types of endodontic irrigants

AIM: The purpose of this study was to assess in vitro the tooth color alterations associated with two commonly used endodontic irrigants, the chlorhexidine gluconate (CHX) and the sodium hypochlorite (NaOCl) up to 15 days post-treatment. Additionally, the possible influence of endodontic access preparation on tooth color was investigated. MATERIALS AND METHODS: Thirty intact human anterior teeth were used. Black adhesive tape with a 4 mm diameter window was used to standardize the enamel surface intended for color analysis. After the access cavity, preparation and the initial root canal negotiation with stainless steel hand files, the root canal shaping was completed with rotary nickel-titanium files. The teeth were divided into three groups (n = 10). Conventional syringe irrigation was performed with one irrigant for each group. The enamel surfaces were colorimetrically evaluated before access cavity, after cavity preparation and at 1, 3, 7 and 15 days post-treatment. The CIE color parameters (L*, a*, b*) were recorded and averaged for each material and the corresponding color differences (ΔE) were calculated and statistically analyzed. RESULTS: The most significant factor in tooth color alteration, during the endodontic treatment, was the access preparation. CHX and NaOCl caused tooth color changes comparable with the saline. CHX and NaOCl did not increase the tooth color changes relative to the values induced by the access preparation. CONCLUSION: The two endodontic irrigants were not able to induce tooth color alteration to a greater extent than the access preparation. CLINICAL SIGNIFICANCE: Chlorhexidine and NaOCl cannot be considered as discoloring endodontic materials. The most contributing factor in tooth color alteration during endodontic treatment in the anterior teeth is access preparation

Comparative evaluation of chair-side saliva tests according to current dental status in adult patient

Background: this cross-sectional study evaluated the correlation of commercial chair-side saliva tests with caries status in adults. Methods: teeth in 87 adults (20–40 years old) were clinically examined for carious lesions according to International Caries Detection and Assessment System (ICDAS) criteria. The Decayed-Missing-Filling-Tooth (DMFT) and Decayed-Missing-Filling-Surface (DMFS) indexes at D1 (lesions 1–6 according to ICDAS criteria) and D3 (lesions 4–6 according to ICDAS criteria threshold and the number of active lesions, according to the Lesion Activity Assessment (LAA)) criteria were measured. The saliva parameters measured by chair-side tests were stimulated and non-stimulated saliva flow rate, saliva consistency, saliva pH, saliva buffer capacity, and lactic acid production. The statistical analyses performed were Student t-test and Mann–Whitney U test at a = 0.05 significant level. Results: the low resting saliva pH was related to a high value of DMFT (D1) index (p = 0.007). Conclusions: among the saliva parameters measured, the values of low resting pH are associated with increased DMFT at threshold D1. None of the chair-side available saliva tests evaluated can accurately underline the tooth carious status. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Early responses of human pulp to direct capping with resin adhesive systems and calcium hydroxide

Objective: Early responses of human pulp to Prime&Bond/phosphoric acid, Clearfil SE Bond, Clearfil S3 Bond and Dycal were investigated ex vivo. Materials and methods: The three adhesives, Dycal or buffer (DPBS) were applied directly onto the pulp of human teeth slices that were placed in culture for 4 days. Cell viability was monitored by the MTT assay during the culture period. After 4 days, tissue integrity was examined by hematoxylin–eosin staining. Vimentin levels were assessed by Western blotting. TUNEL assay was applied for apoptotic cell detection at specific pulp areas. Results: Profound reduction of cell viability and tissue integrity was observed in adhesive-treated groups, while the impact of Dycal was found to be less harmful. Extended apoptosis was caused mostly by the Clearfil SE and Prime&Bond. All adhesives reduced Vimentin levels. Significance: The study provides evidence that early pulp responses to direct capping with different adhesive systems or calcium hydroxide may vary significantly and underline the need for further studies in relevant ex vivo systems. © 2018 The Academy of Dental Material