Dens invaginatus may be seen as a developmental malformation. It is characterized by an invagination of the enamel and dentin, creating a lumen inside the affected tooth, which may extend as deep as the apical foramen. Oehlers Type IIIb is considered the most challenging clinical conditions. The purpose of this study is to discuss the nonsurgical endodontic management of vital and necrotic dens invaginatus Type IIIb cases. Due to the complex anatomical consideration of dens invaginatus Type IIIb, endodontic treatment is extremely technique sensitive. A conservative approach was used in a vital case to treat the invaginated lumen only, to preserve the vitality of the pulp, and a more invasive approach was used in a necrotic case to debride the lumen and necrotic pulp for proper disinfection of the root canal system. Although different, all the approaches were successful. The clinical signs and symptoms were resolved. The vital case remains vital after 19 months, and the recall radiographs were able to show satisfactory periapical healing both in vital and necrotic cases. Due to the highly complex anatomy of dens invaginatus Type IIIb, the decision of preserving the pulp vitality may not be related only to pulpal diagnosis but also to the technical requirements of the treatment. Although very technically sensitive, it may be possible to treat the invaginated lumen exclusively, while preserving the vitality of the pulp. Necrotic cases may require a more aggressive approach to achieve a favorable prognosis.

Aim: To compare design, metallurgy and mechanical performance of the ProTaper (PT) Ultimate system with instruments of similar dimensions from the ProGlider, PT Gold and PT Universal systems.Methodology: New PT Ultimate instruments (n = 248) were compared with instruments of similar dimensions from ProGlider (n = 31), PT Gold (n = 155) and PT Universal (n = 155) systems regarding their number of spirals, helical angle, blade symmetry, tip geometry, surface finishing, nickel/titanium ratio, phase transformation temperatures and mechanical performance. One-way anova and nonparametric Mood's median tests were used for statistical comparison (α = 5%).Results: All instruments had symmetrical blades without radial lands or flat sides, similar surface finishing and an almost equiatomic nickel/titanium ratio, whilst the number of spirals, helical angles and the tip geometry were different. PT Ultimate instruments showed 3 distinct heat treatments that matched with the colour of their metal wire. Slider and ProGlider instruments had similar R-phase start (Rs) and Rphase finish (Rf) temperatures. SX, F1, F2, F3 and Shaper instruments showed equivalent heat treatments (Rs ~45.6°C and Rf ~28.3°C) that were similar to their PT Gold counterparts (Rs ~47.9°C and Rf ~28.2°C), but completely distinct to the PT Universal ones (Rs ~16.2°C and Rf ~−18.2°C). Amongst the PT Ultimate instruments, the lowest maximum torques were observed in the SX (0.44 N cm), Slider (0.45 N cm) and Shaper (0.60 N cm) instruments, whilst the highest was noted in the FXL (4.90 N cm).PT Ultimate Slider and ProGlider had similar torsional (~0.40 N cm) and bending loads (~145.0 gf) (p = 1.000), whilst the other PT Ultimate instruments showed statistically significantly lower maximum torque, higher angle of rotation and lower bending load (higher flexibility) than their counterparts of the PT Universal and PT Gold systems. Conclusions:The PT Ultimate system comprises instruments with 3 distinct heat treatments that showed similar phase transformation temperatures to their heattreated analogues. PT Ultimate instruments presented lower torsional strength and

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Objective: The traditional face-to-face or on-site lecturing methods are still among the most common forms of delivering knowledge to students in dental education. However, other innovative learning methodologies have the potential to complement, or even improve, the effectiveness and quality of teaching. The aim of this online survey was to analyze the receptivity of endodontics practitioners to a specific online teaching format of a multi-day congress, mimicking an on-site conference, and perceive whether the participants regarded it as an effective way of acquiring knowledge with application in their clinical practice activity. Methods: An online questionnaire, composed of 17 items, was sent during the last day of a multi-day online congress. Four strands of information were taken into account: demographics; previous online formation experience; personal involvement in the underway online congress; and overview of the online congress concept. Participation was voluntary and anonymous. Total counts, frequencies and descriptive statistics were generated by using SurveyMonkey software. Results: A total of 1.827 answers were delivered, which represented a return rate of 15.8%. The results indicated that most of the participants agree that online learning could be a good alternative to the traditional on-site learning methodology in improving their practical abilities. In addition, the present survey found that the majority of the attendees support the use of computers as an assisting tool and only 18.0% reported difficulties when using technologies. A high number of practitioners recognized a favourable cost-benefit ratio of using online lessons and stated they would recommend others to participate in online meetings as well. Conclusion: Overall, the present results suggest that online learning may be used successfully to improve student’s knowledge and enhance their abilities to apply acquired content in clinical situations. Moreover, the participants felt online learning to be effective, engaging and with a favourable cost-benefit ratio.

Abstract:Bark from Pinus Pinaster is an interesting source of polyphenolic natural compounds, that can be used successful1y as total or partial replacement of conventional phenolic resins. These compounds, among other applications, are used as adhesives in the wood agglomerate industry. In this kind of application some problems remain to be solved in order to obtain a Pine extract of commercial value. It is necessary to optimise tije extraction procedure and select a suitable method for the quantification of the tannin content of the bark. In order to study these problems, the tannin extraction from the Pine bark was tested with an alkaline solution (NaOH), and with a fractionation procedure based on a sequence of an organic (ethanol) and aqueous extraction. The phenolic content of each extract or fraction was evaluated by the FolinCiocalteu colorimetric assay for total phenols and two procedures using the Stiasny reaction: the gravimetric Stiasny method and the indirect colorimetric procedure that uses the Folin-Ciocalteu reagent to evaluate the total phenols present in the extract solution before and after it condenses with formaldehyde. The yield value when the alkaline extraction is used is substantially higher than the values obtained with organic or aqueous solutions. However, the selectivity of the process is low. In fact, it was found that the alkaline extract Formaldehyde Condensable Phenolic Material (FCPM) content represents 95-96 % of the total phenols content of the extract but this fraction is only~40 % of the total mass of extract. So, the alkaline extract is relatively poor in phenolic material, exhibiting a large variety of non-phenolic extractives. On the other end, ethanol provides a very rich phenolic extract, in which 96 % of total phenols are condensable with formaldehyde, but exhibits a relatively low extraction yield. The aqueous extract presents the lowest extraction yield with low content either in phenolic material as in FCPM, but, as most of the